--- a/browser/confvars.sh
+++ b/browser/confvars.sh
@@ -59,11 +59,12 @@ if test "$OS_TARGET" = "WINNT" -o "$OS_T
   MOZ_FOLD_LIBS=1
 fi
 MOZ_WEBGL_CONFORMANT=1
 # Enable navigator.mozPay
 MOZ_PAY=1
 # Enable activities. These are used for FxOS developers currently.
 MOZ_ACTIVITIES=1
 MOZ_JSDOWNLOADS=1
+MOZ_WEBM_ENCODER=1
 # Enable exact rooting on desktop.
 JSGC_USE_EXACT_ROOTING=1
 

--- a/config/external/moz.build
+++ b/config/external/moz.build
@@ -22,16 +22,19 @@ if CONFIG['MOZ_TREMOR']:
     external_dirs += ['media/libtremor']
 
 if CONFIG['MOZ_OPUS']:
     external_dirs += ['media/libopus']
 
 if CONFIG['MOZ_WEBM']:
     external_dirs += ['media/libnestegg']
 
+if CONFIG['MOZ_WEBM_ENCODER']:
+    external_dirs += ['media/libmkv']
+
 if CONFIG['MOZ_VPX'] and not CONFIG['MOZ_NATIVE_LIBVPX']:
     external_dirs += ['media/libvpx']
 
 if CONFIG['MOZ_OGG']:
     external_dirs += ['media/libogg', 'media/libtheora']
 
 if not CONFIG['MOZ_NATIVE_PNG']:
     external_dirs += ['media/libpng']

--- a/configure.in
+++ b/configure.in
@@ -5541,16 +5541,21 @@ fi
 if test -n "$MOZ_TREMOR"; then
     AC_DEFINE(MOZ_TREMOR)
 fi
 
 if test -n "$MOZ_OPUS"; then
     AC_DEFINE(MOZ_OPUS)
 fi
 
+if test -n "$MOZ_WEBM_ENCODER"; then
+    AC_DEFINE(MOZ_WEBM_ENCODER)
+fi
+AC_SUBST(MOZ_WEBM_ENCODER)
+
 dnl ==================================
 dnl = Check alsa availability on Linux
 dnl ==================================
 
 dnl If using Linux, ensure that the alsa library is available
 if test "$OS_TARGET" = "Linux"; then
     MOZ_ALSA=1
 fi

--- a/content/media/encoder/MediaEncoder.cpp
+++ b/content/media/encoder/MediaEncoder.cpp
@@ -9,16 +9,21 @@
 #include "prlog.h"
 #include "mozilla/Preferences.h"
 
 #ifdef MOZ_OGG
 #include "OggWriter.h"
 #endif
 #ifdef MOZ_OPUS
 #include "OpusTrackEncoder.h"
+
+#endif
+
+#ifdef MOZ_VORBIS
+#include "VorbisTrackEncoder.h"
 #endif
 #ifdef MOZ_WEBM_ENCODER
 #include "VorbisTrackEncoder.h"
 #include "VP8TrackEncoder.h"
 #include "WebMWriter.h"
 #endif
 #ifdef MOZ_OMX_ENCODER
 #include "OmxTrackEncoder.h"

--- a/content/media/encoder/TrackEncoder.cpp
+++ b/content/media/encoder/TrackEncoder.cpp
@@ -123,16 +123,30 @@ AudioTrackEncoder::InterleaveTrackData(A
                          aChunk.mVolume, aOutputChannels, aOutput);
   } else {
     InterleaveAndConvertBuffer(aChunk.mChannelData.Elements(),
                                aChunk.mBufferFormat, aDuration, aChunk.mVolume,
                                aOutputChannels, aOutput);
   }
 }
 
+/*static*/
+void
+AudioTrackEncoder::DeInterleaveTrackData(AudioDataValue* aInput,
+                                         int32_t aDuration,
+                                         int32_t aChannels,
+                                         AudioDataValue* aOutput)
+{
+  for (int32_t i = 0; i < aChannels; ++i) {
+    for(int32_t j = 0; j < aDuration; ++j) {
+      aOutput[i * aDuration + j] = aInput[i + j * aChannels];
+    }
+  }
+}
+
 void
 VideoTrackEncoder::NotifyQueuedTrackChanges(MediaStreamGraph* aGraph,
                                             TrackID aID,
                                             TrackRate aTrackRate,
                                             TrackTicks aTrackOffset,
                                             uint32_t aTrackEvents,
                                             const MediaSegment& aQueuedMedia)
 {

--- a/content/media/encoder/TrackEncoder.h
+++ b/content/media/encoder/TrackEncoder.h
@@ -153,16 +153,23 @@ public:
    * to up-mix or down-mix the channel data if the channels number of this chunk
    * is different from aOutputChannels. The channel data from aChunk might be
    * modified by up-mixing.
    */
   static void InterleaveTrackData(AudioChunk& aChunk, int32_t aDuration,
                                   uint32_t aOutputChannels,
                                   AudioDataValue* aOutput);
 
+  /**
+   * De-interleaves the aInput data and stores the result into aOutput.
+   * No up-mix or down-mix operations inside.
+   */
+  static void DeInterleaveTrackData(AudioDataValue* aInput, int32_t aDuration,
+                                    int32_t aChannels, AudioDataValue* aOutput);
+
 protected:
   /**
    * Number of samples per channel in a pcm buffer. This is also the value of
    * frame size required by audio encoder, and mReentrantMonitor will be
    * notified when at least this much data has been added to mRawSegment.
    */
   virtual int GetPacketDuration() { return 0; }
 

--- a/content/media/encoder/TrackMetadataBase.h
+++ b/content/media/encoder/TrackMetadataBase.h
@@ -13,16 +13,17 @@ namespace mozilla {
 // A class represent meta data for various codec format. Only support one track information.
 class TrackMetadataBase
 {
 public:
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(TrackMetadataBase)
   enum MetadataKind {
     METADATA_OPUS,    // Represent the Opus metadata
     METADATA_VP8,
+    METADATA_VORBIS,
     METADATA_AVC,
     METADATA_AAC,
     METADATA_UNKNOWN  // Metadata Kind not set
   };
   virtual ~TrackMetadataBase() {}
   // Return the specific metadata kind
   virtual MetadataKind GetKind() const = 0;
 };

new file mode 100644
--- /dev/null
+++ b/content/media/encoder/VP8TrackEncoder.cpp
@@ -0,0 +1,472 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "VP8TrackEncoder.h"
+#include "vpx/vp8cx.h"
+#include "vpx/vpx_encoder.h"
+#include "VideoUtils.h"
+#include "prsystem.h"
+#include "WebMWriter.h"
+
+namespace mozilla {
+
+#ifdef PR_LOGGING
+PRLogModuleInfo* gVP8TrackEncoderLog;
+#define VP8LOG(msg, ...) PR_LOG(gVP8TrackEncoderLog, PR_LOG_DEBUG, \
+                                  (msg, ##__VA_ARGS__))
+// Debug logging macro with object pointer and class name.
+#else
+#define VP8LOG(msg, ...)
+#endif
+
+#define DEFAULT_BITRATE 2500 // in kbit/s
+#define DEFAULT_ENCODE_FRAMERATE 30
+
+VP8TrackEncoder::VP8TrackEncoder()
+  : VideoTrackEncoder()
+  , mEncodedFrameDuration(0)
+  , mEncodedTimestamp(0)
+  , mRemainingTicks(0)
+  , mVPXContext(new vpx_codec_ctx_t())
+  , mVPXImageWrapper(new vpx_image_t())
+{
+  MOZ_COUNT_CTOR(VP8TrackEncoder);
+#ifdef PR_LOGGING
+  if (!gVP8TrackEncoderLog) {
+    gVP8TrackEncoderLog = PR_NewLogModule("VP8TrackEncoder");
+  }
+#endif
+}
+
+VP8TrackEncoder::~VP8TrackEncoder()
+{
+  if (mInitialized) {
+    vpx_codec_destroy(mVPXContext);
+  }
+
+  if (mVPXImageWrapper) {
+    vpx_img_free(mVPXImageWrapper);
+  }
+  MOZ_COUNT_DTOR(VP8TrackEncoder);
+}
+
+nsresult
+VP8TrackEncoder::Init(int32_t aWidth, int32_t aHeight, TrackRate aTrackRate)
+{
+  if (aWidth < 1 || aHeight < 1 || aTrackRate <= 0) {
+    return NS_ERROR_FAILURE;
+  }
+
+  ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+
+  mTrackRate = aTrackRate;
+  mEncodedFrameRate = DEFAULT_ENCODE_FRAMERATE;
+  mEncodedFrameDuration = mTrackRate / mEncodedFrameRate;
+  mFrameWidth = aWidth;
+  mFrameHeight = aHeight;
+
+  // Encoder configuration structure.
+  vpx_codec_enc_cfg_t config;
+  memset(&config, 0, sizeof(vpx_codec_enc_cfg_t));
+  if (vpx_codec_enc_config_default(vpx_codec_vp8_cx(), &config, 0)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Creating a wrapper to the image - setting image data to NULL. Actual
+  // pointer will be set in encode. Setting align to 1, as it is meaningless
+  // (actual memory is not allocated).
+  vpx_img_wrap(mVPXImageWrapper, IMG_FMT_I420,
+               mFrameWidth, mFrameHeight, 1, nullptr);
+
+  config.g_w = mFrameWidth;
+  config.g_h = mFrameHeight;
+  // TODO: Maybe we should have various aFrameRate bitrate pair for each devices?
+  // or for different platform
+  config.rc_target_bitrate = DEFAULT_BITRATE; // in kbit/s
+
+  // Setting the time base of the codec
+  config.g_timebase.num = 1;
+  config.g_timebase.den = mTrackRate;
+
+  config.g_error_resilient = 0;
+
+  config.g_lag_in_frames = 0; // 0- no frame lagging
+
+  int32_t number_of_cores = PR_GetNumberOfProcessors();
+  if (mFrameWidth * mFrameHeight > 1280 * 960 && number_of_cores >= 6) {
+    config.g_threads = 3; // 3 threads for 1080p.
+  } else if (mFrameWidth * mFrameHeight > 640 * 480 && number_of_cores >= 3) {
+    config.g_threads = 2; // 2 threads for qHD/HD.
+  } else {
+    config.g_threads = 1; // 1 thread for VGA or less
+  }
+
+  // rate control settings
+  config.rc_dropframe_thresh = 0;
+  config.rc_end_usage = VPX_CBR;
+  config.g_pass = VPX_RC_ONE_PASS;
+  config.rc_resize_allowed = 1;
+  config.rc_undershoot_pct = 100;
+  config.rc_overshoot_pct = 15;
+  config.rc_buf_initial_sz = 500;
+  config.rc_buf_optimal_sz = 600;
+  config.rc_buf_sz = 1000;
+
+  config.kf_mode = VPX_KF_AUTO;
+  // Ensure that we can output one I-frame per second.
+  config.kf_max_dist = mEncodedFrameRate;
+
+  vpx_codec_flags_t flags = 0;
+  flags |= VPX_CODEC_USE_OUTPUT_PARTITION;
+  if (vpx_codec_enc_init(mVPXContext, vpx_codec_vp8_cx(), &config, flags)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  vpx_codec_control(mVPXContext, VP8E_SET_STATIC_THRESHOLD, 1);
+  vpx_codec_control(mVPXContext, VP8E_SET_CPUUSED, -6);
+  vpx_codec_control(mVPXContext, VP8E_SET_TOKEN_PARTITIONS,
+                    VP8_ONE_TOKENPARTITION);
+
+  mInitialized = true;
+  mon.NotifyAll();
+
+  return NS_OK;
+}
+
+already_AddRefed<TrackMetadataBase>
+VP8TrackEncoder::GetMetadata()
+{
+  {
+    // Wait if mEncoder is not initialized.
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    while (!mCanceled && !mInitialized) {
+      mon.Wait();
+    }
+  }
+
+  if (mCanceled || mEncodingComplete) {
+    return nullptr;
+  }
+
+  nsRefPtr<VP8Metadata> meta = new VP8Metadata();
+  meta->mWidth = mFrameWidth;
+  meta->mHeight = mFrameHeight;
+  meta->mEncodedFrameRate = mEncodedFrameRate;
+
+  return meta.forget();
+}
+
+nsresult
+VP8TrackEncoder::GetEncodedPartitions(EncodedFrameContainer& aData)
+{
+  vpx_codec_iter_t iter = nullptr;
+  EncodedFrame::FrameType frameType = EncodedFrame::P_FRAME;
+  nsTArray<uint8_t> frameData;
+  const vpx_codec_cx_pkt_t *pkt = nullptr;
+  while ((pkt = vpx_codec_get_cx_data(mVPXContext, &iter)) != nullptr) {
+    switch (pkt->kind) {
+      case VPX_CODEC_CX_FRAME_PKT: {
+        // Copy the encoded data from libvpx to frameData
+        frameData.AppendElements((uint8_t*)pkt->data.frame.buf,
+                                 pkt->data.frame.sz);
+        break;
+      }
+      default: {
+        break;
+      }
+    }
+    // End of frame
+    if ((pkt->data.frame.flags & VPX_FRAME_IS_FRAGMENT) == 0) {
+      if (pkt->data.frame.flags & VPX_FRAME_IS_KEY) {
+        frameType = EncodedFrame::I_FRAME;
+      }
+      break;
+    }
+  }
+
+  if (!frameData.IsEmpty() &&
+      (pkt->data.frame.pts == mEncodedTimestamp)) {
+    // Copy the encoded data to aData.
+    EncodedFrame* videoData = new EncodedFrame();
+    videoData->SetFrameType(frameType);
+    // Convert the timestamp and duration to Usecs.
+    CheckedInt64 timestamp = FramesToUsecs(mEncodedTimestamp, mTrackRate);
+    if (timestamp.isValid()) {
+      videoData->SetTimeStamp(
+        (uint64_t)FramesToUsecs(mEncodedTimestamp, mTrackRate).value());
+    }
+    CheckedInt64 duration = FramesToUsecs(pkt->data.frame.duration, mTrackRate);
+    if (duration.isValid()) {
+      videoData->SetDuration(
+        (uint64_t)FramesToUsecs(pkt->data.frame.duration, mTrackRate).value());
+    }
+    videoData->SetFrameData(&frameData);
+    VP8LOG("GetEncodedPartitions TimeStamp %lld Duration %lld\n",
+           videoData->GetTimeStamp(), videoData->GetDuration());
+    VP8LOG("frameType %d\n", videoData->GetFrameType());
+    aData.AppendEncodedFrame(videoData);
+  }
+
+  return NS_OK;
+}
+
+void VP8TrackEncoder::PrepareMutedFrame()
+{
+  if (mMuteFrame.IsEmpty()) {
+    CreateMutedFrame(&mMuteFrame);
+  }
+
+  uint32_t yPlanSize = mFrameWidth * mFrameHeight;
+  uint32_t halfWidth = (mFrameWidth + 1) / 2;
+  uint32_t halfHeight = (mFrameHeight + 1) / 2;
+  uint32_t uvPlanSize = halfWidth * halfHeight;
+
+  MOZ_ASSERT(mMuteFrame.Length() >= (yPlanSize + uvPlanSize));
+  uint8_t *y = mMuteFrame.Elements();
+  uint8_t *cb = mMuteFrame.Elements() + yPlanSize;
+  uint8_t *cr = mMuteFrame.Elements() + yPlanSize + uvPlanSize;
+
+  mVPXImageWrapper->planes[PLANE_Y] = y;
+  mVPXImageWrapper->planes[PLANE_U] = cb;
+  mVPXImageWrapper->planes[PLANE_V] = cr;
+  mVPXImageWrapper->stride[VPX_PLANE_Y] = mFrameWidth;
+  mVPXImageWrapper->stride[VPX_PLANE_U] = halfWidth;
+  mVPXImageWrapper->stride[VPX_PLANE_V] = halfWidth;
+}
+
+nsresult VP8TrackEncoder::PrepareRawFrame(VideoChunk &aChunk)
+{
+  if (aChunk.mFrame.GetForceBlack()) {
+    PrepareMutedFrame();
+  } else {
+    layers::Image* img = aChunk.mFrame.GetImage();
+    if (NS_WARN_IF(!img)) {
+      return NS_ERROR_NULL_POINTER;
+    }
+    ImageFormat format = img->GetFormat();
+    if (format != PLANAR_YCBCR) {
+      VP8LOG("Unsupported video format\n");
+      return NS_ERROR_FAILURE;
+    }
+
+    // Cast away constness b/c some of the accessors are non-const
+    layers::PlanarYCbCrImage* yuv =
+    const_cast<layers::PlanarYCbCrImage *>(static_cast<const layers::PlanarYCbCrImage *>(img));
+    // Big-time assumption here that this is all contiguous data coming
+    // from getUserMedia or other sources.
+    MOZ_ASSERT(yuv);
+    const layers::PlanarYCbCrImage::Data *data = yuv->GetData();
+
+    mVPXImageWrapper->planes[PLANE_Y] = data->mYChannel;
+    mVPXImageWrapper->planes[PLANE_U] = data->mCbChannel;
+    mVPXImageWrapper->planes[PLANE_V] = data->mCrChannel;
+    mVPXImageWrapper->stride[VPX_PLANE_Y] = data->mYStride;
+    mVPXImageWrapper->stride[VPX_PLANE_U] = data->mCbCrStride;
+    mVPXImageWrapper->stride[VPX_PLANE_V] = data->mCbCrStride;
+  }
+  return NS_OK;
+}
+
+// These two define value used in GetNextEncodeOperation to determine the
+// EncodeOperation for next target frame.
+#define I_FRAME_RATIO (0.5)
+#define SKIP_FRAME_RATIO (0.75)
+
+/**
+ * Compares the elapsed time from the beginning of GetEncodedTrack and
+ * the processed frame duration in mSourceSegment
+ * in order to set the nextEncodeOperation for next target frame.
+ */
+VP8TrackEncoder::EncodeOperation
+VP8TrackEncoder::GetNextEncodeOperation(TimeDuration aTimeElapsed,
+                                        TrackTicks aProcessedDuration)
+{
+  int64_t durationInUsec =
+    FramesToUsecs(aProcessedDuration + mEncodedFrameDuration,
+                  mTrackRate).value();
+  if (aTimeElapsed.ToMicroseconds() > (durationInUsec * SKIP_FRAME_RATIO)) {
+    // The encoder is too slow.
+    // We should skip next frame to consume the mSourceSegment.
+    return SKIP_FRAME;
+  } else if (aTimeElapsed.ToMicroseconds() > (durationInUsec * I_FRAME_RATIO)) {
+    // The encoder is a little slow.
+    // We force the encoder to encode an I-frame to accelerate.
+    return ENCODE_I_FRAME;
+  } else {
+    return ENCODE_NORMAL_FRAME;
+  }
+}
+
+TrackTicks
+VP8TrackEncoder::CalculateRemainingTicks(TrackTicks aDurationCopied,
+                                         TrackTicks aEncodedDuration)
+{
+  return mRemainingTicks + aEncodedDuration - aDurationCopied;
+}
+
+// Try to extend the encodedDuration as long as possible if the target frame
+// has a long duration.
+TrackTicks
+VP8TrackEncoder::CalculateEncodedDuration(TrackTicks aDurationCopied)
+{
+  TrackTicks temp64 = aDurationCopied;
+  TrackTicks encodedDuration = mEncodedFrameDuration;
+  temp64 -= mRemainingTicks;
+  while (temp64 > mEncodedFrameDuration) {
+    temp64 -= mEncodedFrameDuration;
+    encodedDuration += mEncodedFrameDuration;
+  }
+  return encodedDuration;
+}
+
+/**
+ * Encoding flow in GetEncodedTrack():
+ * 1: Check the mInitialized state and the packet duration.
+ * 2: Move the data from mRawSegment to mSourceSegment.
+ * 3: Encode the video chunks in mSourceSegment in a for-loop.
+ * 3.1: Pick the video chunk by mRemainingTicks.
+ * 3.2: Calculate the encoding duration for the parameter of vpx_codec_encode().
+ *      The encoding duration is a multiple of mEncodedFrameDuration.
+ * 3.3: Setup the video chunk to mVPXImageWrapper by PrepareRawFrame().
+ * 3.4: Send frame into vp8 encoder by vpx_codec_encode().
+ * 3.5: Get the output frame from encoder by calling GetEncodedPartitions().
+ * 3.6: Calculate the mRemainingTicks for next target frame.
+ * 3.7: Set the nextEncodeOperation for the next target frame.
+ *      There is a heuristic: If the frame duration we have processed in
+ *      mSourceSegment is 100ms, means that we can't spend more than 100ms to
+ *      encode it.
+ * 4. Remove the encoded chunks in mSourceSegment after for-loop.
+ *
+ * Ex1: Input frame rate is 100 => input frame duration is 10ms for each.
+ *     mEncodedFrameRate is 30 => output frame duration is 33ms.
+ *     In this case, the frame duration in mSourceSegment will be:
+ *     1st : 0~10ms
+ *     2nd : 10~20ms
+ *     3rd : 20~30ms
+ *     4th : 30~40ms
+ *     ...
+ *     The VP8 encoder will take the 1st and 4th frames to encode. At beginning
+ *     mRemainingTicks is 0 for 1st frame, then the mRemainingTicks is set
+ *     to 23 to pick the 4th frame. (mEncodedFrameDuration - 1st frame duration)
+ *
+ * Ex2: Input frame rate is 25 => frame duration is 40ms for each.
+ *     mEncodedFrameRate is 30 => output frame duration is 33ms.
+ *     In this case, the frame duration in mSourceSegment will be:
+ *     1st : 0~40ms
+ *     2nd : 40~80ms
+ *     3rd : 80~120ms
+ *     4th : 120~160ms
+ *     ...
+ *     Because the input frame duration is 40ms larger than 33ms, so the first
+ *     encoded frame duration will be 66ms by calling CalculateEncodedDuration.
+ *     And the mRemainingTicks will be set to 26
+ *     (CalculateRemainingTicks 0+66-40) in order to pick the next frame(2nd)
+ *     in mSourceSegment.
+ */
+nsresult
+VP8TrackEncoder::GetEncodedTrack(EncodedFrameContainer& aData)
+{
+  {
+    // Move all the samples from mRawSegment to mSourceSegment. We only hold
+    // the monitor in this block.
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    // Wait if mEncoder is not initialized, or when not enough raw data, but is
+    // not the end of stream nor is being canceled.
+    while (!mCanceled && (!mInitialized ||
+           (mRawSegment.GetDuration() + mSourceSegment.GetDuration() <
+            mEncodedFrameDuration && !mEndOfStream))) {
+      mon.Wait();
+    }
+    if (mCanceled || mEncodingComplete) {
+      return NS_ERROR_FAILURE;
+    }
+    mSourceSegment.AppendFrom(&mRawSegment);
+  }
+
+  VideoSegment::ChunkIterator iter(mSourceSegment);
+  TrackTicks durationCopied = 0;
+  TrackTicks totalProcessedDuration = 0;
+  TimeStamp timebase = TimeStamp::Now();
+  EncodeOperation nextEncodeOperation = ENCODE_NORMAL_FRAME;
+
+  for (; !iter.IsEnded(); iter.Next()) {
+    VideoChunk &chunk = *iter;
+    // Accumulate chunk's duration to durationCopied until it reaches
+    // mRemainingTicks.
+    durationCopied += chunk.GetDuration();
+    MOZ_ASSERT(mRemainingTicks <= mEncodedFrameDuration);
+    VP8LOG("durationCopied %lld mRemainingTicks %lld\n",
+           durationCopied, mRemainingTicks);
+    if (durationCopied >= mRemainingTicks) {
+      VP8LOG("nextEncodeOperation is %d\n",nextEncodeOperation);
+      // Calculate encodedDuration for this target frame.
+      TrackTicks encodedDuration = CalculateEncodedDuration(durationCopied);
+
+      // Encode frame.
+      if (nextEncodeOperation != SKIP_FRAME) {
+        nsresult rv = PrepareRawFrame(chunk);
+        NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+        // Encode the data with VP8 encoder
+        int flags = (nextEncodeOperation == ENCODE_NORMAL_FRAME) ?
+                    0 : VPX_EFLAG_FORCE_KF;
+        if (vpx_codec_encode(mVPXContext, mVPXImageWrapper, mEncodedTimestamp,
+                             (unsigned long)encodedDuration, flags,
+                             VPX_DL_REALTIME)) {
+          return NS_ERROR_FAILURE;
+        }
+        // Get the encoded data from VP8 encoder.
+        GetEncodedPartitions(aData);
+      } else {
+        // SKIP_FRAME
+        // Extend the duration of the last encoded data in aData
+        // because this frame will be skip.
+        nsRefPtr<EncodedFrame> last = nullptr;
+        last = aData.GetEncodedFrames().LastElement();
+        if (last) {
+          last->SetDuration(last->GetDuration() + encodedDuration);
+        }
+      }
+      // Move forward the mEncodedTimestamp.
+      mEncodedTimestamp += encodedDuration;
+      totalProcessedDuration += durationCopied;
+      // Calculate mRemainingTicks for next target frame.
+      mRemainingTicks = CalculateRemainingTicks(durationCopied,
+                                                encodedDuration);
+
+      // Check the remain data is enough for next target frame.
+      if (mSourceSegment.GetDuration() - totalProcessedDuration
+          >= mEncodedFrameDuration) {
+        TimeDuration elapsedTime = TimeStamp::Now() - timebase;
+        nextEncodeOperation = GetNextEncodeOperation(elapsedTime,
+                                                     totalProcessedDuration);
+        // Reset durationCopied for next iteration.
+        durationCopied = 0;
+      } else {
+        // Process done, there is no enough data left for next iteration,
+        // break the for-loop.
+        break;
+      }
+    }
+  }
+  // Remove the chunks we have processed.
+  mSourceSegment.RemoveLeading(totalProcessedDuration);
+  VP8LOG("RemoveLeading %lld\n",totalProcessedDuration);
+
+  // End of stream, pull the rest frames in encoder.
+  if (mEndOfStream) {
+    VP8LOG("mEndOfStream is true\n");
+    mEncodingComplete = true;
+    if (vpx_codec_encode(mVPXContext, nullptr, mEncodedTimestamp,
+                         mEncodedFrameDuration, 0, VPX_DL_REALTIME)) {
+      return NS_ERROR_FAILURE;
+    }
+    GetEncodedPartitions(aData);
+  }
+
+  return NS_OK ;
+}
+
+} // namespace mozilla

new file mode 100644
--- /dev/null
+++ b/content/media/encoder/VP8TrackEncoder.h
@@ -0,0 +1,93 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef VP8TrackEncoder_h_
+#define VP8TrackEncoder_h_
+
+#include "TrackEncoder.h"
+#include "vpx/vpx_codec.h"
+
+namespace mozilla {
+
+typedef struct vpx_codec_ctx vpx_codec_ctx_t;
+typedef struct vpx_codec_enc_cfg vpx_codec_enc_cfg_t;
+typedef struct vpx_image vpx_image_t;
+
+/**
+ * VP8TrackEncoder implements VideoTrackEncoder by using libvpx library.
+ * We implement a realtime and fixed FPS encoder. In order to achieve that,
+ * there is a pick target frame and drop frame encoding policy implemented in
+ * GetEncodedTrack.
+ */
+class VP8TrackEncoder : public VideoTrackEncoder
+{
+  enum EncodeOperation {
+    ENCODE_NORMAL_FRAME, // VP8 track encoder works normally.
+    ENCODE_I_FRAME, // The next frame will be encoded as I-Frame.
+    SKIP_FRAME, // Skip the next frame.
+  };
+public:
+  VP8TrackEncoder();
+  virtual ~VP8TrackEncoder();
+
+  already_AddRefed<TrackMetadataBase> GetMetadata() MOZ_FINAL MOZ_OVERRIDE;
+
+  nsresult GetEncodedTrack(EncodedFrameContainer& aData) MOZ_FINAL MOZ_OVERRIDE;
+
+protected:
+  nsresult Init(int32_t aWidth, int32_t aHeight,
+                TrackRate aTrackRate) MOZ_FINAL MOZ_OVERRIDE;
+
+private:
+  // Calculate the target frame's encoded duration.
+  TrackTicks CalculateEncodedDuration(TrackTicks aDurationCopied);
+
+  // Calculate the mRemainingTicks for next target frame.
+  TrackTicks CalculateRemainingTicks(TrackTicks aDurationCopied,
+                                     TrackTicks aEncodedDuration);
+
+  // Get the EncodeOperation for next target frame.
+  EncodeOperation GetNextEncodeOperation(TimeDuration aTimeElapsed,
+                                         TrackTicks aProcessedDuration);
+
+  // Get the encoded data from encoder to aData.
+  nsresult GetEncodedPartitions(EncodedFrameContainer& aData);
+
+  // Prepare the input data to the mVPXImageWrapper for encoding.
+  nsresult PrepareRawFrame(VideoChunk &aChunk);
+
+  // Prepare the muted frame data to the mVPXImageWrapper for encoding.
+  void PrepareMutedFrame();
+
+  // Output frame rate.
+  uint32_t mEncodedFrameRate;
+  // Duration for the output frame, reciprocal to mEncodedFrameRate.
+  TrackTicks mEncodedFrameDuration;
+  // Encoded timestamp.
+  TrackTicks mEncodedTimestamp;
+  // Duration to the next encode frame.
+  TrackTicks mRemainingTicks;
+
+  // Muted frame, we only create it once.
+  nsTArray<uint8_t> mMuteFrame;
+
+  /**
+   * A local segment queue which takes the raw data out from mRawSegment in the
+   * call of GetEncodedTrack(). Since we implement the fixed FPS encoding
+   * policy, it needs to be global in order to store the leftover segments
+   * taken from mRawSegment.
+   */
+  VideoSegment mSourceSegment;
+
+  // VP8 relative members.
+  // Codec context structure.
+  nsAutoPtr<vpx_codec_ctx_t> mVPXContext;
+  // Image Descriptor.
+  nsAutoPtr<vpx_image_t> mVPXImageWrapper;
+};
+
+} // namespace mozilla
+
+#endif

new file mode 100644
--- /dev/null
+++ b/content/media/encoder/VorbisTrackEncoder.cpp
@@ -0,0 +1,238 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+#include "VorbisTrackEncoder.h"
+#include <ogg/ogg.h>
+#include <vorbis/vorbisenc.h>
+#include "WebMWriter.h"
+
+// One actually used: Encoding using a VBR quality mode. The usable range is -.1
+// (lowest quality, smallest file) to 1. (highest quality, largest file).
+// Example quality mode .4: 44kHz stereo coupled, roughly 128kbps VBR
+// ret = vorbis_encode_init_vbr(&vi,2,44100,.4);
+static const float BASE_QUALITY = 0.4f;
+
+namespace mozilla {
+
+#undef LOG
+#ifdef PR_LOGGING
+PRLogModuleInfo* gVorbisTrackEncoderLog;
+#define VORBISLOG(msg, ...) PR_LOG(gVorbisTrackEncoderLog, PR_LOG_DEBUG, \
+                             (msg, ##__VA_ARGS__))
+#else
+#define VORBISLOG(msg, ...)
+#endif
+
+VorbisTrackEncoder::VorbisTrackEncoder()
+  : AudioTrackEncoder()
+{
+  MOZ_COUNT_CTOR(VorbisTrackEncoder);
+#ifdef PR_LOGGING
+  if (!gVorbisTrackEncoderLog) {
+    gVorbisTrackEncoderLog = PR_NewLogModule("VorbisTrackEncoder");
+  }
+#endif
+}
+
+VorbisTrackEncoder::~VorbisTrackEncoder()
+{
+  MOZ_COUNT_DTOR(VorbisTrackEncoder);
+  if (mInitialized) {
+    vorbis_block_clear(&mVorbisBlock);
+    vorbis_dsp_clear(&mVorbisDsp);
+    vorbis_info_clear(&mVorbisInfo);
+  }
+}
+
+nsresult
+VorbisTrackEncoder::Init(int aChannels, int aSamplingRate)
+{
+  if (aChannels <= 0 || aChannels > 8) {
+    VORBISLOG("aChannels <= 0 || aChannels > 8");
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  // This monitor is used to wake up other methods that are waiting for encoder
+  // to be completely initialized.
+  ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+  mChannels = aChannels;
+  mSamplingRate = aSamplingRate;
+
+  int ret = 0;
+  vorbis_info_init(&mVorbisInfo);
+
+  ret = vorbis_encode_init_vbr(&mVorbisInfo, mChannels, mSamplingRate,
+                               BASE_QUALITY);
+
+  mInitialized = (ret == 0);
+
+  if (mInitialized) {
+    // Set up the analysis state and auxiliary encoding storage
+    vorbis_analysis_init(&mVorbisDsp, &mVorbisInfo);
+    vorbis_block_init(&mVorbisDsp, &mVorbisBlock);
+  }
+
+  mon.NotifyAll();
+
+  return ret == 0 ? NS_OK : NS_ERROR_FAILURE;
+}
+
+void VorbisTrackEncoder::WriteLacing(nsTArray<uint8_t> *aOutput, int32_t aLacing)
+{
+  while (aLacing > 255) {
+    aLacing -= 255;
+    aOutput->AppendElement(255);
+  }
+  aOutput->AppendElement((uint8_t)aLacing);
+}
+
+already_AddRefed<TrackMetadataBase>
+VorbisTrackEncoder::GetMetadata()
+{
+  {
+    // Wait if encoder is not initialized.
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+    while (!mCanceled && !mInitialized) {
+      mon.Wait();
+    }
+  }
+
+  if (mCanceled || mEncodingComplete) {
+    return nullptr;
+  }
+
+  // Vorbis codec specific data
+  // http://matroska.org/technical/specs/codecid/index.html
+  nsRefPtr<VorbisMetadata> meta = new VorbisMetadata();
+  meta->mBitDepth = 32; // float for desktop
+  meta->mChannels = mChannels;
+  meta->mSamplingFrequency = mSamplingRate;
+  ogg_packet header;
+  ogg_packet header_comm;
+  ogg_packet header_code;
+  // Add comment
+  vorbis_comment vorbisComment;
+  vorbis_comment_init(&vorbisComment);
+  vorbis_comment_add_tag(&vorbisComment, "ENCODER",
+    NS_LITERAL_CSTRING("Mozilla VorbisTrackEncoder " MOZ_APP_UA_VERSION).get());
+  vorbis_analysis_headerout(&mVorbisDsp, &vorbisComment,
+                            &header,&header_comm, &header_code);
+  vorbis_comment_clear(&vorbisComment);
+  // number of distinct packets - 1
+  meta->mData.AppendElement(2);
+  // Xiph-style lacing header.bytes, header_comm.bytes
+  WriteLacing(&(meta->mData), header.bytes);
+  WriteLacing(&(meta->mData), header_comm.bytes);
+
+  // Append the three packets
+  meta->mData.AppendElements(header.packet, header.bytes);
+  meta->mData.AppendElements(header_comm.packet, header_comm.bytes);
+  meta->mData.AppendElements(header_code.packet, header_code.bytes);
+
+  return meta.forget();
+}
+
+void
+VorbisTrackEncoder::GetEncodedFrames(EncodedFrameContainer& aData)
+{
+  // vorbis does some data preanalysis, then divvies up blocks for
+  // more involved (potentially parallel) processing. Get a single
+  // block for encoding now.
+  while (vorbis_analysis_blockout(&mVorbisDsp, &mVorbisBlock) == 1) {
+    ogg_packet oggPacket;
+    if (vorbis_analysis(&mVorbisBlock, &oggPacket) == 0) {
+      VORBISLOG("vorbis_analysis_blockout block size %d", oggPacket.bytes);
+      EncodedFrame* audiodata = new EncodedFrame();
+      audiodata->SetFrameType(EncodedFrame::AUDIO_FRAME);
+      nsTArray<uint8_t> frameData;
+      frameData.AppendElements(oggPacket.packet, oggPacket.bytes);
+      audiodata->SetFrameData(&frameData);
+      aData.AppendEncodedFrame(audiodata);
+    }
+  }
+}
+
+nsresult
+VorbisTrackEncoder::GetEncodedTrack(EncodedFrameContainer& aData)
+{
+  if (mEosSetInEncoder) {
+    return NS_OK;
+  }
+
+  nsAutoPtr<AudioSegment> sourceSegment;
+  sourceSegment = new AudioSegment();
+  {
+    // Move all the samples from mRawSegment to sourceSegment. We only hold
+    // the monitor in this block.
+    ReentrantMonitorAutoEnter mon(mReentrantMonitor);
+
+    // Wait if mEncoder is not initialized, or when not enough raw data, but is
+    // not the end of stream nor is being canceled.
+    while (!mCanceled && mRawSegment.GetDuration() < GetPacketDuration() &&
+           !mEndOfStream) {
+      mon.Wait();
+    }
+    VORBISLOG("GetEncodedTrack passes wait, duration is %lld\n",
+      mRawSegment.GetDuration());
+    if (mCanceled || mEncodingComplete) {
+      return NS_ERROR_FAILURE;
+    }
+
+    sourceSegment->AppendFrom(&mRawSegment);
+  }
+
+  if (mEndOfStream && (sourceSegment->GetDuration() == 0)
+      && !mEosSetInEncoder) {
+    mEncodingComplete = true;
+    mEosSetInEncoder = true;
+    VORBISLOG("[Vorbis] Done encoding.");
+    vorbis_analysis_wrote(&mVorbisDsp, 0);
+    GetEncodedFrames(aData);
+
+    return NS_OK;
+  }
+
+  // Start encoding data.
+  AudioSegment::ChunkIterator iter(*sourceSegment);
+
+  AudioDataValue **vorbisBuffer =
+    vorbis_analysis_buffer(&mVorbisDsp, (int)sourceSegment->GetDuration());
+
+  int framesCopied = 0;
+  nsAutoTArray<AudioDataValue, 9600> interleavedPcm;
+  nsAutoTArray<AudioDataValue, 9600> nonInterleavedPcm;
+  interleavedPcm.SetLength(sourceSegment->GetDuration() * mChannels);
+  nonInterleavedPcm.SetLength(sourceSegment->GetDuration() * mChannels);
+  while (!iter.IsEnded()) {
+    AudioChunk chunk = *iter;
+    int frameToCopy = chunk.GetDuration();
+    if (!chunk.IsNull()) {
+      InterleaveTrackData(chunk, frameToCopy, mChannels,
+                          interleavedPcm.Elements() + framesCopied * mChannels);
+    } else { // empty data
+      memset(interleavedPcm.Elements() + framesCopied * mChannels, 0,
+             frameToCopy * mChannels * sizeof(AudioDataValue));
+    }
+    framesCopied += frameToCopy;
+    iter.Next();
+  }
+  // De-interleave the interleavedPcm.
+  DeInterleaveTrackData(interleavedPcm.Elements(), framesCopied, mChannels,
+                        nonInterleavedPcm.Elements());
+  // Copy the nonInterleavedPcm to vorbis buffer.
+  for(uint8_t i = 0; i < mChannels; ++i) {
+    memcpy(vorbisBuffer[i], nonInterleavedPcm.Elements() + framesCopied * i,
+           framesCopied * sizeof(AudioDataValue));
+  }
+
+  // Now the vorbisBuffer contain the all data in non-interleaved.
+  // Tell the library how much we actually submitted.
+  vorbis_analysis_wrote(&mVorbisDsp, framesCopied);
+  VORBISLOG("vorbis_analysis_wrote framesCopied %d\n", framesCopied);
+  GetEncodedFrames(aData);
+
+  return NS_OK;
+}
+
+} // namespace mozilla

new file mode 100644
--- /dev/null
+++ b/content/media/encoder/VorbisTrackEncoder.h
@@ -0,0 +1,54 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef VorbisTrackEncoder_h_
+#define VorbisTrackEncoder_h_
+
+#include "TrackEncoder.h"
+#include "nsCOMPtr.h"
+#include <vorbis/codec.h>
+
+namespace mozilla {
+
+class VorbisTrackEncoder : public AudioTrackEncoder
+{
+public:
+  VorbisTrackEncoder();
+  virtual ~VorbisTrackEncoder();
+
+  already_AddRefed<TrackMetadataBase> GetMetadata() MOZ_FINAL MOZ_OVERRIDE;
+
+  nsresult GetEncodedTrack(EncodedFrameContainer& aData) MOZ_FINAL MOZ_OVERRIDE;
+
+protected:
+  /**
+   * http://xiph.org/vorbis/doc/libvorbis/vorbis_analysis_buffer.html
+   * We use 1024 samples for the write buffer; libvorbis will construct packets
+   * with the appropriate duration for the encoding mode internally.
+   */
+  int GetPacketDuration() MOZ_FINAL MOZ_OVERRIDE {
+    return 1024;
+  }
+
+  nsresult Init(int aChannels, int aSamplingRate) MOZ_FINAL MOZ_OVERRIDE;
+
+private:
+  // Write Xiph-style lacing to aOutput.
+  void WriteLacing(nsTArray<uint8_t> *aOutput, int32_t aLacing);
+
+  // Get the encoded data from vorbis encoder and append into aData.
+  void GetEncodedFrames(EncodedFrameContainer& aData);
+
+  // vorbis codec members
+  // Struct that stores all the static vorbis bitstream settings.
+  vorbis_info mVorbisInfo;
+  // Central working state for the PCM->packet encoder.
+  vorbis_dsp_state mVorbisDsp;
+  // Local working space for PCM->packet encode.
+  vorbis_block mVorbisBlock;
+};
+
+}
+#endif

--- a/content/media/encoder/moz.build
+++ b/content/media/encoder/moz.build
@@ -15,21 +15,29 @@ EXPORTS += [
     'TrackMetadataBase.h',
 ]
 
 UNIFIED_SOURCES += [
     'MediaEncoder.cpp',
     'TrackEncoder.cpp',
 ]
 
+if CONFIG['MOZ_OMX_ENCODER']:
+    EXPORTS += ['OmxTrackEncoder.h']
+    UNIFIED_SOURCES += ['OmxTrackEncoder.cpp']
+
 if CONFIG['MOZ_OPUS']:
     EXPORTS += ['OpusTrackEncoder.h']
     UNIFIED_SOURCES += ['OpusTrackEncoder.cpp']
 
-if CONFIG['MOZ_OMX_ENCODER']:
-    EXPORTS += ['OmxTrackEncoder.h']
-    UNIFIED_SOURCES += ['OmxTrackEncoder.cpp']
+if CONFIG['MOZ_WEBM_ENCODER']:
+    EXPORTS += ['VorbisTrackEncoder.h',
+                'VP8TrackEncoder.h',
+    ]
+    UNIFIED_SOURCES += ['VorbisTrackEncoder.cpp',
+                        'VP8TrackEncoder.cpp',
+    ]
 
 FAIL_ON_WARNINGS = True
 
 FINAL_LIBRARY = 'gklayout'
 
 include('/ipc/chromium/chromium-config.mozbuild')

new file mode 100644
--- /dev/null
+++ b/content/media/webm/EbmlComposer.cpp
@@ -0,0 +1,177 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "EbmlComposer.h"
+#include "libmkv/EbmlIDs.h"
+#include "libmkv/EbmlWriter.h"
+#include "libmkv/WebMElement.h"
+#include "prtime.h"
+
+namespace mozilla {
+
+// Timecode scale in nanoseconds
+static const unsigned long TIME_CODE_SCALE = 1000000;
+// The WebM header size without audio CodecPrivateData
+static const int32_t DEFAULT_HEADER_SIZE = 1024;
+
+void EbmlComposer::GenerateHeader()
+{
+  // Write the EBML header.
+  EbmlGlobal ebml;
+  // The WEbM header default size usually smaller than 1k.
+  nsAutoArrayPtr<uint8_t> buffer(new uint8_t[DEFAULT_HEADER_SIZE +
+                                             mCodecPrivateData.Length()]);
+  ebml.buf = buffer.get();
+  ebml.offset = 0;
+  writeHeader(&ebml);
+  {
+    EbmlLoc segEbmlLoc, ebmlLocseg, ebmlLoc;
+    Ebml_StartSubElement(&ebml, &segEbmlLoc, Segment);
+    {
+      Ebml_StartSubElement(&ebml, &ebmlLocseg, SeekHead);
+      // Todo: We don't know the exact sizes of encoded data and ignore this section.
+      Ebml_EndSubElement(&ebml, &ebmlLocseg);
+      writeSegmentInformation(&ebml, &ebmlLoc, TIME_CODE_SCALE, 0);
+      {
+        EbmlLoc trackLoc;
+        Ebml_StartSubElement(&ebml, &trackLoc, Tracks);
+        {
+          char cid_string[8];
+          // Video
+          if (mWidth > 0 && mHeight > 0) {
+            strcpy(cid_string, "V_VP8");
+            writeVideoTrack(&ebml, 0x1, 0, cid_string,
+                            mWidth, mHeight, mFrameRate);
+          }
+          // Audio
+          if (mCodecPrivateData.Length() > 0) {
+            strcpy(cid_string, "A_VORBIS");
+            writeAudioTrack(&ebml, 0x2, 0x0, cid_string, mSampleFreq,
+                            mChannels, mCodecPrivateData.Elements(),
+                            mCodecPrivateData.Length());
+          }
+        }
+        Ebml_EndSubElement(&ebml, &trackLoc);
+      }
+    }
+    // The Recording length is unknow and ignore write the whole Segment element size
+  }
+  MOZ_ASSERT_IF(ebml.offset > DEFAULT_HEADER_SIZE + mCodecPrivateData.Length(),
+                "write more data > EBML_BUFFER_SIZE");
+  mClusterBuffs.AppendElement();
+  mClusterBuffs.LastElement().SetLength(ebml.offset);
+  memcpy(mClusterBuffs.LastElement().Elements(), ebml.buf, ebml.offset);
+}
+
+void EbmlComposer::FinishCluster()
+{
+  MOZ_ASSERT(mClusterLengthLoc > 0 );
+  MOZ_ASSERT(mClusterHeaderIndex > 0);
+  for (uint32_t i = 0; i < mClusterBuffs.Length(); i ++ ) {
+    mClusterCanFlushBuffs.AppendElement()->SwapElements(mClusterBuffs[i]);
+  }
+  mClusterBuffs.Clear();
+  EbmlGlobal ebml;
+  EbmlLoc ebmlLoc;
+  ebmlLoc.offset = mClusterLengthLoc;
+  ebml.offset = mClusterCanFlushBuffs[mClusterHeaderIndex].Length();
+  ebml.buf = mClusterCanFlushBuffs[mClusterHeaderIndex].Elements();
+  Ebml_EndSubElement(&ebml, &ebmlLoc);
+  mClusterHeaderIndex = 0;
+  mClusterLengthLoc = 0;
+}
+
+void
+EbmlComposer::WriteSimpleBlock(EncodedFrame* aFrame)
+{
+  EbmlGlobal ebml;
+  ebml.offset = 0;
+
+  if (aFrame->GetFrameType() == EncodedFrame::FrameType::I_FRAME && mClusterHeaderIndex > 0) {
+    FinishCluster();
+  }
+
+  mClusterBuffs.AppendElement();
+  mClusterBuffs.LastElement().SetLength(aFrame->GetFrameData().Length() + DEFAULT_HEADER_SIZE);
+  ebml.buf = mClusterBuffs.LastElement().Elements();
+
+  if (aFrame->GetFrameType() == EncodedFrame::FrameType::I_FRAME) {
+    EbmlLoc ebmlLoc;
+    Ebml_StartSubElement(&ebml, &ebmlLoc, Cluster);
+    mClusterHeaderIndex = mClusterBuffs.Length() - 1; // current cluster header array index
+    mClusterLengthLoc = ebmlLoc.offset;
+    if (aFrame->GetFrameType() != EncodedFrame::FrameType::AUDIO_FRAME) {
+      mClusterTimecode = aFrame->GetTimeStamp() / PR_USEC_PER_MSEC;
+    }
+    Ebml_SerializeUnsigned(&ebml, Timecode, mClusterTimecode);
+  }
+
+  if (aFrame->GetFrameType() != EncodedFrame::FrameType::AUDIO_FRAME) {
+    short timeCode = aFrame->GetTimeStamp() / PR_USEC_PER_MSEC - mClusterTimecode;
+    writeSimpleBlock(&ebml, 0x1, timeCode, aFrame->GetFrameType() ==
+                     EncodedFrame::FrameType::I_FRAME,
+                     0, 0, (unsigned char*)aFrame->GetFrameData().Elements(),
+                     aFrame->GetFrameData().Length());
+  } else {
+    writeSimpleBlock(&ebml, 0x2, 0, false,
+                     0, 0, (unsigned char*)aFrame->GetFrameData().Elements(),
+                     aFrame->GetFrameData().Length());
+  }
+  MOZ_ASSERT_IF(ebml.offset > DEFAULT_HEADER_SIZE + aFrame->GetFrameData().Length(),
+                "write more data > EBML_BUFFER_SIZE");
+  mClusterBuffs.LastElement().SetLength(ebml.offset);
+}
+
+void
+EbmlComposer::SetVideoConfig(uint32_t aWidth, uint32_t aHeight,
+                             float aFrameRate)
+{
+  MOZ_ASSERT(aWidth > 0, "Width should > 0");
+  MOZ_ASSERT(aHeight > 0, "Height should > 0");
+  MOZ_ASSERT(aFrameRate > 0, "FrameRate should > 0");
+  mWidth = aWidth;
+  mHeight = aHeight;
+  mFrameRate = aFrameRate;
+}
+
+void
+EbmlComposer::SetAudioConfig(uint32_t aSampleFreq, uint32_t aChannels,
+                             uint32_t aBitDepth)
+{
+  MOZ_ASSERT(aSampleFreq > 0, "SampleFreq should > 0");
+  MOZ_ASSERT(aBitDepth > 0, "BitDepth should > 0");
+  MOZ_ASSERT(aChannels > 0, "Channels should > 0");
+  mSampleFreq = aSampleFreq;
+  mBitDepth = aBitDepth;
+  mChannels = aChannels;
+}
+
+void
+EbmlComposer::ExtractBuffer(nsTArray<nsTArray<uint8_t> >* aDestBufs,
+                            uint32_t aFlag)
+{
+  if ((aFlag & ContainerWriter::FLUSH_NEEDED) && mClusterHeaderIndex > 0) {
+    FinishCluster();
+  }
+  // aDestBufs may have some element
+  for (uint32_t i = 0; i < mClusterCanFlushBuffs.Length(); i ++ ) {
+    aDestBufs->AppendElement()->SwapElements(mClusterCanFlushBuffs[i]);
+  }
+  mClusterCanFlushBuffs.Clear();
+}
+
+EbmlComposer::EbmlComposer()
+  : mClusterHeaderIndex(0)
+  , mClusterLengthLoc(0)
+  , mClusterTimecode(0)
+  , mWidth(0)
+  , mHeight(0)
+  , mFrameRate(0)
+  , mSampleFreq(0)
+  , mBitDepth(0)
+  , mChannels(0)
+{}
+
+}

new file mode 100644
--- /dev/null
+++ b/content/media/webm/EbmlComposer.h
@@ -0,0 +1,75 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef EbmlComposer_h_
+#define EbmlComposer_h_
+#include "nsTArray.h"
+#include "ContainerWriter.h"
+
+namespace mozilla {
+
+/*
+ * A WebM muxer helper for package the valid WebM format.
+ */
+class EbmlComposer {
+public:
+  EbmlComposer();
+  /*
+   * Assign the parameter which header required.
+   */
+  void SetVideoConfig(uint32_t aWidth, uint32_t aHeight, float aFrameRate);
+
+  void SetAudioConfig(uint32_t aSampleFreq, uint32_t aChannels,
+                      uint32_t bitDepth);
+  /*
+   * Set the CodecPrivateData for writing in header.
+   */
+  void SetAudioCodecPrivateData(nsTArray<uint8_t>& aBufs)
+  {
+    mCodecPrivateData.AppendElements(aBufs);
+  }
+  /*
+   * Generate the whole WebM header and output to mBuff.
+   */
+  void GenerateHeader();
+  /*
+   * Insert media encoded buffer into muxer and it would be package
+   * into SimpleBlock. If no cluster is opened, new cluster will start for writing.
+   */
+  void WriteSimpleBlock(EncodedFrame* aFrame);
+  /*
+   * Get valid cluster data.
+   */
+  void ExtractBuffer(nsTArray<nsTArray<uint8_t> >* aDestBufs,
+                     uint32_t aFlag = 0);
+private:
+  // Close current cluster and move data to mClusterCanFlushBuffs.
+  void FinishCluster();
+  // The temporary storage for cluster data.
+  nsTArray<nsTArray<uint8_t> > mClusterBuffs;
+  // The storage which contain valid cluster data.
+  nsTArray<nsTArray<uint8_t> > mClusterCanFlushBuffs;
+  // Indicate the header index in mClusterBuffs.
+  uint32_t mClusterHeaderIndex;
+  // The cluster length position.
+  uint64_t mClusterLengthLoc;
+  // Audio codec specific header data.
+  nsTArray<uint8_t> mCodecPrivateData;
+
+  // The timecode of the cluster.
+  uint64_t mClusterTimecode;
+
+  // Video configuration
+  int mWidth;
+  int mHeight;
+  float mFrameRate;
+  // Audio configuration
+  float mSampleFreq;
+  int mBitDepth;
+  int mChannels;
+};
+
+}
+#endif

new file mode 100644
--- /dev/null
+++ b/content/media/webm/WebMWriter.cpp
@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "WebMWriter.h"
+#include "EbmlComposer.h"
+
+namespace mozilla {
+
+WebMWriter::WebMWriter(uint32_t aTrackTypes) : ContainerWriter()
+{
+  mMetadataRequiredFlag = aTrackTypes;
+  mEbmlComposer = new EbmlComposer();
+}
+
+nsresult
+WebMWriter::WriteEncodedTrack(const EncodedFrameContainer& aData,
+                              uint32_t aFlags)
+{
+  for (uint32_t i = 0 ; i < aData.GetEncodedFrames().Length(); i++) {
+    mEbmlComposer->WriteSimpleBlock(aData.GetEncodedFrames().ElementAt(i).get());
+  }
+  return NS_OK;
+}
+
+nsresult
+WebMWriter::GetContainerData(nsTArray<nsTArray<uint8_t> >* aOutputBufs,
+                             uint32_t aFlags)
+{
+  mEbmlComposer->ExtractBuffer(aOutputBufs, aFlags);
+  if (aFlags & ContainerWriter::FLUSH_NEEDED) {
+    mIsWritingComplete = true;
+  }
+  return NS_OK;
+}
+
+nsresult
+WebMWriter::SetMetadata(TrackMetadataBase* aMetadata)
+{
+  MOZ_ASSERT(aMetadata);
+  if (aMetadata->GetKind() == TrackMetadataBase::METADATA_VP8) {
+    VP8Metadata* meta = static_cast<VP8Metadata*>(aMetadata);
+    MOZ_ASSERT(meta, "Cannot find vp8 encoder metadata");
+    mEbmlComposer->SetVideoConfig(meta->mWidth, meta->mHeight,
+                                  meta->mEncodedFrameRate);
+    mMetadataRequiredFlag = mMetadataRequiredFlag & ~ContainerWriter::HAS_VIDEO;
+  }
+
+  if (aMetadata->GetKind() == TrackMetadataBase::METADATA_VORBIS) {
+    VorbisMetadata* meta = static_cast<VorbisMetadata*>(aMetadata);
+    MOZ_ASSERT(meta, "Cannot find vorbis encoder metadata");
+    mEbmlComposer->SetAudioConfig(meta->mSamplingFrequency, meta->mChannels, meta->mBitDepth);
+    mEbmlComposer->SetAudioCodecPrivateData(meta->mData);
+    mMetadataRequiredFlag = mMetadataRequiredFlag & ~ContainerWriter::HAS_AUDIO;
+  }
+
+  if (!mMetadataRequiredFlag) {
+    mEbmlComposer->GenerateHeader();
+  }
+  return NS_OK;
+}
+
+} // mozilla namespace

new file mode 100644
--- /dev/null
+++ b/content/media/webm/WebMWriter.h
@@ -0,0 +1,70 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef WebMWriter_h_
+#define WebMWriter_h_
+
+#include "ContainerWriter.h"
+
+namespace mozilla {
+
+class EbmlComposer;
+
+// Vorbis meta data structure
+class VorbisMetadata : public TrackMetadataBase
+{
+public:
+  nsTArray<uint8_t> mData;
+  int32_t mChannels;
+  int32_t mBitDepth;
+  float mSamplingFrequency;
+  MetadataKind GetKind() const MOZ_OVERRIDE { return METADATA_VORBIS; }
+};
+
+// VP8 meta data structure
+class VP8Metadata : public TrackMetadataBase
+{
+public:
+  int32_t mWidth;
+  int32_t mHeight;
+  int32_t mEncodedFrameRate;
+  MetadataKind GetKind() const MOZ_OVERRIDE { return METADATA_VP8; }
+};
+
+/**
+ * WebM writer helper
+ * This class accepts encoder to set audio or video meta data or
+ * encoded data to ebml Composer, and get muxing data through GetContainerData.
+ * The ctor/dtor run in the MediaRecorder thread, others run in MediaEncoder thread.
+ */
+class WebMWriter : public ContainerWriter
+{
+public:
+  // aTrackTypes indicate this muxer should multiplex into Video only or A/V foramt.
+  // Run in MediaRecorder thread
+  WebMWriter(uint32_t aTrackTypes);
+  // WriteEncodedTrack inserts raw packets into WebM stream.
+  nsresult WriteEncodedTrack(const EncodedFrameContainer &aData,
+                             uint32_t aFlags = 0) MOZ_OVERRIDE;
+
+  // GetContainerData outputs multiplexing data.
+  // aFlags indicates the muxer should enter into finished stage and flush out
+  // queue data.
+  nsresult GetContainerData(nsTArray<nsTArray<uint8_t> >* aOutputBufs,
+                            uint32_t aFlags = 0) MOZ_OVERRIDE;
+
+  // Assign metadata into muxer
+  nsresult SetMetadata(TrackMetadataBase* aMetadata) MOZ_OVERRIDE;
+
+private:
+  nsAutoPtr<EbmlComposer> mEbmlComposer;
+
+  // Indicate what kind of meta data needed in the writer.
+  // If this value become 0, it means writer can start to generate header.
+  uint8_t mMetadataRequiredFlag;
+};
+
+}
+#endif

--- a/content/media/webm/moz.build
+++ b/content/media/webm/moz.build
@@ -10,11 +10,17 @@ EXPORTS += [
 ]
 
 UNIFIED_SOURCES += [
     'WebMBufferedParser.cpp',
     'WebMDecoder.cpp',
     'WebMReader.cpp',
 ]
 
+if CONFIG['MOZ_WEBM_ENCODER']:
+    EXPORTS += ['WebMWriter.h']
+    UNIFIED_SOURCES += ['EbmlComposer.cpp',
+                        'WebMWriter.cpp',
+    ]
+
 FAIL_ON_WARNINGS = True
 
 FINAL_LIBRARY = 'gklayout'

--- a/layout/media/symbols.def.in
+++ b/layout/media/symbols.def.in
@@ -24,16 +24,27 @@ nestegg_track_count
 nestegg_get_cue_point
 nestegg_track_seek
 nestegg_track_type
 nestegg_track_video_params
 nestegg_tstamp_scale
 nestegg_has_cues
 nestegg_sniff
 #endif
+#ifdef MOZ_WEBM_ENCODER
+writeSimpleBlock
+writeHeader
+writeSegmentInformation
+writeVideoTrack
+writeAudioTrack
+Ebml_Serialize
+Ebml_SerializeUnsigned
+Ebml_StartSubElement
+Ebml_EndSubElement
+#endif
 #ifdef MOZ_VPX
 #ifndef MOZ_NATIVE_LIBVPX
 vpx_codec_control_
 vpx_codec_dec_init_ver
 vpx_codec_decode
 vpx_codec_destroy
 vpx_codec_get_frame
 vpx_codec_peek_stream_info

new file mode 100644
--- /dev/null
+++ b/media/libmkv/AUTHORS
@@ -0,0 +1,100 @@
+# This file is automatically generated from the git commit history
+# by tools/gen_authors.sh.
+
+Aaron Watry <awatry@gmail.com>
+Abo Talib Mahfoodh <ab.mahfoodh@gmail.com>
+Adrian Grange <agrange@google.com>
+Ahmad Sharif <asharif@google.com>
+Alexander Voronov <avoronov@graphics.cs.msu.ru>
+Alex Converse <alex.converse@gmail.com>
+Alexis Ballier <aballier@gentoo.org>
+Alok Ahuja <waveletcoeff@gmail.com>
+Alpha Lam <hclam@google.com>
+A.Mahfoodh <ab.mahfoodh@gmail.com>
+Ami Fischman <fischman@chromium.org>
+Andoni Morales Alastruey <ylatuya@gmail.com>
+Andres Mejia <mcitadel@gmail.com>
+Aron Rosenberg <arosenberg@logitech.com>
+Attila Nagy <attilanagy@google.com>
+changjun.yang <changjun.yang@intel.com>
+chm <chm@rock-chips.com>
+Christian Duvivier <cduvivier@google.com>
+Daniel Kang <ddkang@google.com>
+Deb Mukherjee <debargha@google.com>
+Dmitry Kovalev <dkovalev@google.com>
+Dragan Mrdjan <dmrdjan@mips.com>
+Erik Niemeyer <erik.a.niemeyer@gmail.com>
+Fabio Pedretti <fabio.ped@libero.it>
+Frank Galligan <fgalligan@google.com>
+Fredrik Söderquist <fs@opera.com>
+Fritz Koenig <frkoenig@google.com>
+Gaute Strokkenes <gaute.strokkenes@broadcom.com>
+Giuseppe Scrivano <gscrivano@gnu.org>
+Guillaume Martres <gmartres@google.com>
+Guillermo Ballester Valor <gbvalor@gmail.com>
+Hangyu Kuang <hkuang@google.com>
+Henrik Lundin <hlundin@google.com>
+Hui Su <huisu@google.com>
+Ivan Maltz <ivanmaltz@google.com>
+James Berry <jamesberry@google.com>
+James Zern <jzern@google.com>
+Jan Kratochvil <jan.kratochvil@redhat.com>
+Janne Salonen <jsalonen@google.com>
+Jeff Faust <jfaust@google.com>
+Jeff Muizelaar <jmuizelaar@mozilla.com>
+Jeff Petkau <jpet@chromium.org>
+Jim Bankoski <jimbankoski@google.com>
+Jingning Han <jingning@google.com>
+Johann Koenig <johannkoenig@google.com>
+John Koleszar <jkoleszar@google.com>
+Joshua Bleecher Snyder <josh@treelinelabs.com>
+Joshua Litt <joshualitt@google.com>
+Justin Clift <justin@salasaga.org>
+Justin Lebar <justin.lebar@gmail.com>
+KO Myung-Hun <komh@chollian.net>
+Lou Quillio <louquillio@google.com>
+Luca Barbato <lu_zero@gentoo.org>
+Makoto Kato <makoto.kt@gmail.com>
+Mans Rullgard <mans@mansr.com>
+Marco Paniconi <marpan@google.com>
+Mark Mentovai <mark@chromium.org>
+Martin Ettl <ettl.martin78@googlemail.com>
+Martin Storsjo <martin@martin.st>
+Matthew Heaney <matthewjheaney@chromium.org>
+Michael Kohler <michaelkohler@live.com>
+Mike Frysinger <vapier@chromium.org>
+Mike Hommey <mhommey@mozilla.com>
+Mikhal Shemer <mikhal@google.com>
+Morton Jonuschat <yabawock@gmail.com>
+Parag Salasakar <img.mips1@gmail.com>
+Pascal Massimino <pascal.massimino@gmail.com>
+Patrik Westin <patrik.westin@gmail.com>
+Paul Wilkins <paulwilkins@google.com>
+Pavol Rusnak <stick@gk2.sk>
+Paweł Hajdan <phajdan@google.com>
+Philip Jägenstedt <philipj@opera.com>
+Priit Laes <plaes@plaes.org>
+Rafael Ávila de Espíndola <rafael.espindola@gmail.com>
+Rafaël Carré <funman@videolan.org>
+Ralph Giles <giles@xiph.org>
+Rob Bradford <rob@linux.intel.com>
+Ronald S. Bultje <rbultje@google.com>
+Sami Pietilä <samipietila@google.com>
+Scott Graham <scottmg@chromium.org>
+Scott LaVarnway <slavarnway@google.com>
+Shimon Doodkin <helpmepro1@gmail.com>
+Stefan Holmer <holmer@google.com>
+Suman Sunkara <sunkaras@google.com>
+Taekhyun Kim <takim@nvidia.com>
+Takanori MATSUURA <t.matsuu@gmail.com>
+Tamar Levy <tamar.levy@intel.com>
+Tero Rintaluoma <teror@google.com>
+Thijs Vermeir <thijsvermeir@gmail.com>
+Timothy B. Terriberry <tterribe@xiph.org>
+Tom Finegan <tomfinegan@google.com>
+Vignesh Venkatasubramanian <vigneshv@google.com>
+Yaowu Xu <yaowu@google.com>
+Yunqing Wang <yunqingwang@google.com>
+Google Inc.
+The Mozilla Foundation
+The Xiph.Org Foundation

new file mode 100644
--- /dev/null
+++ b/media/libmkv/EbmlBufferWriter.c
@@ -0,0 +1,79 @@
+// #include <strmif.h>
+#include "EbmlBufferWriter.h"
+#include "EbmlWriter.h"
+// #include <cassert>
+// #include <limits>
+// #include <malloc.h>  //_alloca
+#include <stdlib.h>
+#include <wchar.h>
+#include <string.h>
+
+void
+Ebml_Serialize(EbmlGlobal *glob, const void *buffer_in, int buffer_size, unsigned long len)
+{
+  /* buffer_size:
+   * 1 - int8_t;
+   * 2 - int16_t;
+   * 3 - int32_t;
+   * 4 - int64_t;
+   */
+  long i;
+  for(i = len-1; i >= 0; i--) {
+    unsigned char x;
+    if (buffer_size == 1) {
+      x = (char)(*(const int8_t *)buffer_in >> (i * 8));
+	} else if (buffer_size == 2) {
+      x = (char)(*(const int16_t *)buffer_in >> (i * 8));
+	} else if (buffer_size == 4) {
+      x = (char)(*(const int32_t *)buffer_in >> (i * 8));
+	} else if (buffer_size == 8) {
+      x = (char)(*(const int64_t *)buffer_in >> (i * 8));
+	}
+    Ebml_Write(glob, &x, 1);
+  }
+}
+
+void Ebml_Write(EbmlGlobal *glob, const void *buffer_in, unsigned long len) {
+  unsigned char *src = glob->buf;
+  src += glob->offset;
+  memcpy(src, buffer_in, len);
+  glob->offset += len;
+}
+
+static void _Serialize(EbmlGlobal *glob, const unsigned char *p, const unsigned char *q) {
+  while (q != p) {
+    --q;
+
+    memcpy(&(glob->buf[glob->offset]), q, 1);
+    glob->offset++;
+  }
+}
+
+/*
+void Ebml_Serialize(EbmlGlobal *glob, const void *buffer_in, unsigned long len) {
+  // assert(buf);
+
+  const unsigned char *const p = (const unsigned char *)(buffer_in);
+  const unsigned char *const q = p + len;
+
+  _Serialize(glob, p, q);
+}
+*/
+
+void Ebml_StartSubElement(EbmlGlobal *glob, EbmlLoc *ebmlLoc, unsigned long class_id) {
+  unsigned long long unknownLen = 0x01FFFFFFFFFFFFFFLL;
+  Ebml_WriteID(glob, class_id);
+  ebmlLoc->offset = glob->offset;
+  // todo this is always taking 8 bytes, this may need later optimization
+  Ebml_Serialize(glob, (void *)&unknownLen,sizeof(unknownLen), 8); // this is a key that says lenght unknown
+}
+
+void Ebml_EndSubElement(EbmlGlobal *glob, EbmlLoc *ebmlLoc) {
+  unsigned long long size = glob->offset - ebmlLoc->offset - 8;
+  unsigned long long curOffset = glob->offset;
+  glob->offset = ebmlLoc->offset;
+  size |=  0x0100000000000000LL;
+  Ebml_Serialize(glob, &size,sizeof(size), 8);
+  glob->offset = curOffset;
+}
+

new file mode 100644
--- /dev/null
+++ b/media/libmkv/EbmlBufferWriter.h
@@ -0,0 +1,20 @@
+#ifndef EBMLBUFFERWRITER_HPP
+#define EBMLBUFFERWRITER_HPP
+
+typedef struct {
+  unsigned long long offset;
+} EbmlLoc;
+
+typedef struct {
+  unsigned char *buf;
+  unsigned int length;
+  unsigned int offset;
+} EbmlGlobal;
+
+void Ebml_Write(EbmlGlobal *glob, const void *buffer_in, unsigned long len);
+void Ebml_Serialize(EbmlGlobal *glob, const void *buffer_in,
+                    int buffer_size, unsigned long len);
+void Ebml_StartSubElement(EbmlGlobal *glob, EbmlLoc *ebmlLoc, unsigned long class_id);
+void Ebml_EndSubElement(EbmlGlobal *glob,  EbmlLoc *ebmlLoc);
+
+#endif

new file mode 100644
--- /dev/null
+++ b/media/libmkv/EbmlIDs.h
@@ -0,0 +1,231 @@
+/*
+ *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#ifndef MKV_DEFS_HPP
+#define MKV_DEFS_HPP 1
+
+/* Commenting out values not available in webm, but available in matroska */
+
+enum mkv {
+  EBML = 0x1A45DFA3,
+  EBMLVersion = 0x4286,
+  EBMLReadVersion = 0x42F7,
+  EBMLMaxIDLength = 0x42F2,
+  EBMLMaxSizeLength = 0x42F3,
+  DocType = 0x4282,
+  DocTypeVersion = 0x4287,
+  DocTypeReadVersion = 0x4285,
+/* CRC_32 = 0xBF, */
+  Void = 0xEC,
+  SignatureSlot = 0x1B538667,
+  SignatureAlgo = 0x7E8A,
+  SignatureHash = 0x7E9A,
+  SignaturePublicKey = 0x7EA5,
+  Signature = 0x7EB5,
+  SignatureElements = 0x7E5B,
+  SignatureElementList = 0x7E7B,
+  SignedElement = 0x6532,
+  /* segment */
+  Segment = 0x18538067,
+  /* Meta Seek Information */
+  SeekHead = 0x114D9B74,
+  Seek = 0x4DBB,
+  SeekID = 0x53AB,
+  SeekPosition = 0x53AC,
+  /* Segment Information */
+  Info = 0x1549A966,
+/* SegmentUID = 0x73A4, */
+/* SegmentFilename = 0x7384, */
+/* PrevUID = 0x3CB923, */
+/* PrevFilename = 0x3C83AB, */
+/* NextUID = 0x3EB923, */
+/* NextFilename = 0x3E83BB, */
+/* SegmentFamily = 0x4444, */
+/* ChapterTranslate = 0x6924, */
+/* ChapterTranslateEditionUID = 0x69FC, */
+/* ChapterTranslateCodec = 0x69BF, */
+/* ChapterTranslateID = 0x69A5, */
+  TimecodeScale = 0x2AD7B1,
+  Segment_Duration = 0x4489,
+  DateUTC = 0x4461,
+/* Title = 0x7BA9, */
+  MuxingApp = 0x4D80,
+  WritingApp = 0x5741,
+  /* Cluster */
+  Cluster = 0x1F43B675,
+  Timecode = 0xE7,
+/* SilentTracks = 0x5854, */
+/* SilentTrackNumber = 0x58D7, */
+/* Position = 0xA7, */
+  PrevSize = 0xAB,
+  BlockGroup = 0xA0,
+  Block = 0xA1,
+/* BlockVirtual = 0xA2, */
+  BlockAdditions = 0x75A1,
+  BlockMore = 0xA6,
+  BlockAddID = 0xEE,
+  BlockAdditional = 0xA5,
+  BlockDuration = 0x9B,
+/* ReferencePriority = 0xFA, */
+  ReferenceBlock = 0xFB,
+/* ReferenceVirtual = 0xFD, */
+/* CodecState = 0xA4, */
+/* Slices = 0x8E, */
+/* TimeSlice = 0xE8, */
+  LaceNumber = 0xCC,
+/* FrameNumber = 0xCD, */
+/* BlockAdditionID = 0xCB, */
+/* MkvDelay = 0xCE, */
+/* Cluster_Duration = 0xCF, */
+  SimpleBlock = 0xA3,
+/* EncryptedBlock = 0xAF, */
+  /* Track */
+  Tracks = 0x1654AE6B,
+  TrackEntry = 0xAE,
+  TrackNumber = 0xD7,
+  TrackUID = 0x73C5,
+  TrackType = 0x83,
+  FlagEnabled = 0xB9,
+  FlagDefault = 0x88,
+  FlagForced = 0x55AA,
+  FlagLacing = 0x9C,
+/* MinCache = 0x6DE7, */
+/* MaxCache = 0x6DF8, */
+  DefaultDuration = 0x23E383,
+/* TrackTimecodeScale = 0x23314F, */
+/* TrackOffset = 0x537F, */
+  MaxBlockAdditionID = 0x55EE,
+  Name = 0x536E,
+  Language = 0x22B59C,
+  CodecID = 0x86,
+  CodecPrivate = 0x63A2,
+  CodecName = 0x258688,
+/* AttachmentLink = 0x7446, */
+/* CodecSettings = 0x3A9697, */
+/* CodecInfoURL = 0x3B4040, */
+/* CodecDownloadURL = 0x26B240, */
+/* CodecDecodeAll = 0xAA, */
+/* TrackOverlay = 0x6FAB, */
+/* TrackTranslate = 0x6624, */
+/* TrackTranslateEditionUID = 0x66FC, */
+/* TrackTranslateCodec = 0x66BF, */
+/* TrackTranslateTrackID = 0x66A5, */
+  /* video */
+  Video = 0xE0,
+  FlagInterlaced = 0x9A,
+  WEBM_StereoMode = 0x53B8,
+  AlphaMode = 0x53C0,
+  PixelWidth = 0xB0,
+  PixelHeight = 0xBA,
+  PixelCropBottom = 0x54AA,
+  PixelCropTop = 0x54BB,
+  PixelCropLeft = 0x54CC,
+  PixelCropRight = 0x54DD,
+  DisplayWidth = 0x54B0,
+  DisplayHeight = 0x54BA,
+  DisplayUnit = 0x54B2,
+  AspectRatioType = 0x54B3,
+/* ColourSpace = 0x2EB524, */
+/* GammaValue = 0x2FB523, */
+  FrameRate = 0x2383E3,
+  /* end video */
+  /* audio */
+  Audio = 0xE1,
+  SamplingFrequency = 0xB5,
+  OutputSamplingFrequency = 0x78B5,
+  Channels = 0x9F,
+/* ChannelPositions = 0x7D7B, */
+  BitDepth = 0x6264,
+  /* end audio */
+  /* content encoding */
+/* ContentEncodings = 0x6d80, */
+/* ContentEncoding = 0x6240, */
+/* ContentEncodingOrder = 0x5031, */
+/* ContentEncodingScope = 0x5032, */
+/* ContentEncodingType = 0x5033, */
+/* ContentCompression = 0x5034, */
+/* ContentCompAlgo = 0x4254, */
+/* ContentCompSettings = 0x4255, */
+/* ContentEncryption = 0x5035, */
+/* ContentEncAlgo = 0x47e1, */
+/* ContentEncKeyID = 0x47e2, */
+/* ContentSignature = 0x47e3, */
+/* ContentSigKeyID = 0x47e4, */
+/* ContentSigAlgo = 0x47e5, */
+/* ContentSigHashAlgo = 0x47e6, */
+  /* end content encoding */
+  /* Cueing Data */
+  Cues = 0x1C53BB6B,
+  CuePoint = 0xBB,
+  CueTime = 0xB3,
+  CueTrackPositions = 0xB7,
+  CueTrack = 0xF7,
+  CueClusterPosition = 0xF1,
+  CueBlockNumber = 0x5378
+/* CueCodecState = 0xEA, */
+/* CueReference = 0xDB, */
+/* CueRefTime = 0x96, */
+/* CueRefCluster = 0x97, */
+/* CueRefNumber = 0x535F, */
+/* CueRefCodecState = 0xEB, */
+  /* Attachment */
+/* Attachments = 0x1941A469, */
+/* AttachedFile = 0x61A7, */
+/* FileDescription = 0x467E, */
+/* FileName = 0x466E, */
+/* FileMimeType = 0x4660, */
+/* FileData = 0x465C, */
+/* FileUID = 0x46AE, */
+/* FileReferral = 0x4675, */
+  /* Chapters */
+/* Chapters = 0x1043A770, */
+/* EditionEntry = 0x45B9, */
+/* EditionUID = 0x45BC, */
+/* EditionFlagHidden = 0x45BD, */
+/* EditionFlagDefault = 0x45DB, */
+/* EditionFlagOrdered = 0x45DD, */
+/* ChapterAtom = 0xB6, */
+/* ChapterUID = 0x73C4, */
+/* ChapterTimeStart = 0x91, */
+/* ChapterTimeEnd = 0x92, */
+/* ChapterFlagHidden = 0x98, */
+/* ChapterFlagEnabled = 0x4598, */
+/* ChapterSegmentUID = 0x6E67, */
+/* ChapterSegmentEditionUID = 0x6EBC, */
+/* ChapterPhysicalEquiv = 0x63C3, */
+/* ChapterTrack = 0x8F, */
+/* ChapterTrackNumber = 0x89, */
+/* ChapterDisplay = 0x80, */
+/* ChapString = 0x85, */
+/* ChapLanguage = 0x437C, */
+/* ChapCountry = 0x437E, */
+/* ChapProcess = 0x6944, */
+/* ChapProcessCodecID = 0x6955, */
+/* ChapProcessPrivate = 0x450D, */
+/* ChapProcessCommand = 0x6911, */
+/* ChapProcessTime = 0x6922, */
+/* ChapProcessData = 0x6933, */
+  /* Tagging */
+/* Tags = 0x1254C367, */
+/* Tag = 0x7373, */
+/* Targets = 0x63C0, */
+/* TargetTypeValue = 0x68CA, */
+/* TargetType = 0x63CA, */
+/* Tagging_TrackUID = 0x63C5, */
+/* Tagging_EditionUID = 0x63C9, */
+/* Tagging_ChapterUID = 0x63C4, */
+/* AttachmentUID = 0x63C6, */
+/* SimpleTag = 0x67C8, */
+/* TagName = 0x45A3, */
+/* TagLanguage = 0x447A, */
+/* TagDefault = 0x4484, */
+/* TagString = 0x4487, */
+/* TagBinary = 0x4485, */
+};
+#endif

new file mode 100644
--- /dev/null
+++ b/media/libmkv/EbmlWriter.c
@@ -0,0 +1,165 @@
+/*
+ *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+#include "EbmlWriter.h"
+#include <stdlib.h>
+#include <wchar.h>
+#include <string.h>
+#include <limits.h>
+#include "EbmlBufferWriter.h"
+#if defined(_MSC_VER)
+#define LITERALU64(n) n
+#else
+#define LITERALU64(n) n##LLU
+#endif
+
+void Ebml_WriteLen(EbmlGlobal *glob, int64_t val) {
+  /* TODO check and make sure we are not > than 0x0100000000000000LLU */
+  unsigned char size = 8; /* size in bytes to output */
+
+  /* mask to compare for byte size */
+  int64_t minVal = 0xff;
+
+  for (size = 1; size < 8; size ++) {
+    if (val < minVal)
+      break;
+
+    minVal = (minVal << 7);
+  }
+
+  val |= (((uint64_t)0x80) << ((size - 1) * 7));
+
+  Ebml_Serialize(glob, (void *) &val, sizeof(val), size);
+}
+
+void Ebml_WriteString(EbmlGlobal *glob, const char *str) {
+  const size_t size_ = strlen(str);
+  const uint64_t  size = size_;
+  Ebml_WriteLen(glob, size);
+  /* TODO: it's not clear from the spec whether the nul terminator
+   * should be serialized too.  For now we omit the null terminator.
+   */
+  Ebml_Write(glob, str, (unsigned long)size);
+}
+
+void Ebml_WriteUTF8(EbmlGlobal *glob, const wchar_t *wstr) {
+  const size_t strlen = wcslen(wstr);
+
+  /* TODO: it's not clear from the spec whether the nul terminator
+   * should be serialized too.  For now we include it.
+   */
+  const uint64_t  size = strlen;
+
+  Ebml_WriteLen(glob, size);
+  Ebml_Write(glob, wstr, (unsigned long)size);
+}
+
+void Ebml_WriteID(EbmlGlobal *glob, unsigned long class_id) {
+  int len;
+
+  if (class_id >= 0x01000000)
+    len = 4;
+  else if (class_id >= 0x00010000)
+    len = 3;
+  else if (class_id >= 0x00000100)
+    len = 2;
+  else
+    len = 1;
+
+  Ebml_Serialize(glob, (void *)&class_id, sizeof(class_id), len);
+}
+
+void Ebml_SerializeUnsigned32(EbmlGlobal *glob, unsigned long class_id, uint32_t ui) {
+  unsigned char sizeSerialized = 8 | 0x80;
+  Ebml_WriteID(glob, class_id);
+  Ebml_Serialize(glob, &sizeSerialized, sizeof(sizeSerialized), 1);
+  Ebml_Serialize(glob, &ui, sizeof(ui), 4);
+}
+
+void Ebml_SerializeUnsigned64(EbmlGlobal *glob, unsigned long class_id, uint64_t ui) {
+  unsigned char sizeSerialized = 8 | 0x80;
+  Ebml_WriteID(glob, class_id);
+  Ebml_Serialize(glob, &sizeSerialized, sizeof(sizeSerialized), 1);
+  Ebml_Serialize(glob, &ui, sizeof(ui), 8);
+}
+
+void Ebml_SerializeUnsigned(EbmlGlobal *glob, unsigned long class_id, unsigned long ui) {
+  unsigned char size = 8; /* size in bytes to output */
+  unsigned char sizeSerialized = 0;
+  unsigned long minVal;
+
+  Ebml_WriteID(glob, class_id);
+  minVal = 0x7fLU; /* mask to compare for byte size */
+
+  for (size = 1; size < 4; size ++) {
+    if (ui < minVal) {
+      break;
+    }
+
+    minVal <<= 7;
+  }
+
+  sizeSerialized = 0x80 | size;
+  Ebml_Serialize(glob, &sizeSerialized, sizeof(sizeSerialized), 1);
+  Ebml_Serialize(glob, &ui, sizeof(ui), size);
+}
+/* TODO: perhaps this is a poor name for this id serializer helper function */
+void Ebml_SerializeBinary(EbmlGlobal *glob, unsigned long class_id, unsigned long bin) {
+  int size;
+  for (size = 4; size > 1; size--) {
+    if (bin & (unsigned int)0x000000ff << ((size - 1) * 8))
+      break;
+  }
+  Ebml_WriteID(glob, class_id);
+  Ebml_WriteLen(glob, size);
+  Ebml_WriteID(glob, bin);
+}
+
+void Ebml_SerializeFloat(EbmlGlobal *glob, unsigned long class_id, double d) {
+  unsigned char len = 0x88;
+
+  Ebml_WriteID(glob, class_id);
+  Ebml_Serialize(glob, &len, sizeof(len), 1);
+  Ebml_Serialize(glob,  &d, sizeof(d), 8);
+}
+
+void Ebml_WriteSigned16(EbmlGlobal *glob, short val) {
+  signed long out = ((val & 0x003FFFFF) | 0x00200000) << 8;
+  Ebml_Serialize(glob, &out, sizeof(out), 3);
+}
+
+void Ebml_SerializeString(EbmlGlobal *glob, unsigned long class_id, const char *s) {
+  Ebml_WriteID(glob, class_id);
+  Ebml_WriteString(glob, s);
+}
+
+void Ebml_SerializeUTF8(EbmlGlobal *glob, unsigned long class_id, wchar_t *s) {
+  Ebml_WriteID(glob,  class_id);
+  Ebml_WriteUTF8(glob,  s);
+}
+
+void Ebml_SerializeData(EbmlGlobal *glob, unsigned long class_id, unsigned char *data, unsigned long data_length) {
+  Ebml_WriteID(glob, class_id);
+  Ebml_WriteLen(glob, data_length);
+  Ebml_Write(glob,  data, data_length);
+}
+
+void Ebml_WriteVoid(EbmlGlobal *glob, unsigned long vSize) {
+  unsigned char tmp = 0;
+  unsigned long i = 0;
+
+  Ebml_WriteID(glob, 0xEC);
+  Ebml_WriteLen(glob, vSize);
+
+  for (i = 0; i < vSize; i++) {
+    Ebml_Write(glob, &tmp, 1);
+  }
+}
+
+/* TODO Serialize Date */

new file mode 100644
--- /dev/null
+++ b/media/libmkv/EbmlWriter.h
@@ -0,0 +1,53 @@
+/*
+ *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef EBMLWRITER_HPP
+#define EBMLWRITER_HPP
+#include <stddef.h>
+#include "vpx/vpx_integer.h"
+#include "EbmlBufferWriter.h"
+
+/* note: you must define write and serialize functions as well as your own
+ * EBML_GLOBAL
+ *
+ * These functions MUST be implemented
+ */
+
+// typedef struct EbmlGlobal EbmlGlobal;
+// void  Ebml_Serialize(EbmlGlobal *glob, const void *, int, unsigned long);
+// void  Ebml_Write(EbmlGlobal *glob, const void *, unsigned long);
+
+/*****/
+
+void Ebml_WriteLen(EbmlGlobal *glob, int64_t val);
+void Ebml_WriteString(EbmlGlobal *glob, const char *str);
+void Ebml_WriteUTF8(EbmlGlobal *glob, const wchar_t *wstr);
+void Ebml_WriteID(EbmlGlobal *glob, unsigned long class_id);
+void Ebml_SerializeUnsigned32(EbmlGlobal *glob, unsigned long class_id, uint32_t ui);
+void Ebml_SerializeUnsigned64(EbmlGlobal *glob, unsigned long class_id, uint64_t ui);
+void Ebml_SerializeUnsigned(EbmlGlobal *glob, unsigned long class_id, unsigned long ui);
+void Ebml_SerializeBinary(EbmlGlobal *glob, unsigned long class_id, unsigned long ui);
+void Ebml_SerializeFloat(EbmlGlobal *glob, unsigned long class_id, double d);
+/* TODO make this more generic to signed */
+void Ebml_WriteSigned16(EbmlGlobal *glob, short val);
+void Ebml_SerializeString(EbmlGlobal *glob, unsigned long class_id, const char *s);
+void Ebml_SerializeUTF8(EbmlGlobal *glob, unsigned long class_id, wchar_t *s);
+void Ebml_SerializeData(EbmlGlobal *glob, unsigned long class_id, unsigned char *data, unsigned long data_length);
+void Ebml_WriteVoid(EbmlGlobal *glob, unsigned long vSize);
+/* TODO need date function */
+#endif
+
+#ifdef __cplusplus
+}
+#endif

new file mode 100644
--- /dev/null
+++ b/media/libmkv/LICENSE
@@ -0,0 +1,31 @@
+Copyright (c) 2010, The WebM Project authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+  * Redistributions of source code must retain the above copyright
+    notice, this list of conditions and the following disclaimer.
+
+  * Redistributions in binary form must reproduce the above copyright
+    notice, this list of conditions and the following disclaimer in
+    the documentation and/or other materials provided with the
+    distribution.
+
+  * Neither the name of Google, nor the WebM Project, nor the names
+    of its contributors may be used to endorse or promote products
+    derived from this software without specific prior written
+    permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+

new file mode 100644
--- /dev/null
+++ b/media/libmkv/README
@@ -0,0 +1,139 @@
+vpx Multi-Format Codec SDK
+README - 1 August 2013
+
+Welcome to the WebM VP8/VP9 Codec SDK!
+
+COMPILING THE APPLICATIONS/LIBRARIES:
+  The build system used is similar to autotools. Building generally consists of
+  "configuring" with your desired build options, then using GNU make to build
+  the application.
+
+  1. Prerequisites
+
+    * All x86 targets require the Yasm[1] assembler be installed.
+    * All Windows builds require that Cygwin[2] be installed.
+    * Building the documentation requires PHP[3] and Doxygen[4]. If you do not
+      have these packages, you must pass --disable-install-docs to the
+      configure script.
+    * Downloading the data for the unit tests requires curl[5] and sha1sum.
+      sha1sum is provided via the GNU coreutils, installed by default on
+      many *nix platforms, as well as MinGW and Cygwin. If coreutils is not
+      available, a compatible version of sha1sum can be built from
+      source[6]. These requirements are optional if not running the unit
+      tests.
+
+    [1]: http://www.tortall.net/projects/yasm
+    [2]: http://www.cygwin.com
+    [3]: http://php.net
+    [4]: http://www.doxygen.org
+    [5]: http://curl.haxx.se
+    [6]: http://www.microbrew.org/tools/md5sha1sum/
+
+  2. Out-of-tree builds
+  Out of tree builds are a supported method of building the application. For
+  an out of tree build, the source tree is kept separate from the object
+  files produced during compilation. For instance:
+
+    $ mkdir build
+    $ cd build
+    $ ../libvpx/configure <options>
+    $ make
+
+  3. Configuration options
+  The 'configure' script supports a number of options. The --help option can be
+  used to get a list of supported options:
+    $ ../libvpx/configure --help
+
+  4. Cross development
+  For cross development, the most notable option is the --target option. The
+  most up-to-date list of supported targets can be found at the bottom of the
+  --help output of the configure script. As of this writing, the list of
+  available targets is:
+
+    armv5te-android-gcc
+    armv5te-linux-rvct
+    armv5te-linux-gcc
+    armv5te-none-rvct
+    armv6-darwin-gcc
+    armv6-linux-rvct
+    armv6-linux-gcc
+    armv6-none-rvct
+    armv7-android-gcc
+    armv7-darwin-gcc
+    armv7-linux-rvct
+    armv7-linux-gcc
+    armv7-none-rvct
+    armv7-win32-vs11
+    armv7-win32-vs12
+    mips32-linux-gcc
+    ppc32-darwin8-gcc
+    ppc32-darwin9-gcc
+    ppc32-linux-gcc
+    ppc64-darwin8-gcc
+    ppc64-darwin9-gcc
+    ppc64-linux-gcc
+    sparc-solaris-gcc
+    x86-android-gcc
+    x86-darwin8-gcc
+    x86-darwin8-icc
+    x86-darwin9-gcc
+    x86-darwin9-icc
+    x86-darwin10-gcc
+    x86-darwin11-gcc
+    x86-darwin12-gcc
+    x86-darwin13-gcc
+    x86-linux-gcc
+    x86-linux-icc
+    x86-os2-gcc
+    x86-solaris-gcc
+    x86-win32-gcc
+    x86-win32-vs7
+    x86-win32-vs8
+    x86-win32-vs9
+    x86-win32-vs10
+    x86-win32-vs11
+    x86-win32-vs12
+    x86_64-darwin9-gcc
+    x86_64-darwin10-gcc
+    x86_64-darwin11-gcc
+    x86_64-darwin12-gcc
+    x86_64-darwin13-gcc
+    x86_64-linux-gcc
+    x86_64-linux-icc
+    x86_64-solaris-gcc
+    x86_64-win64-gcc
+    x86_64-win64-vs8
+    x86_64-win64-vs9
+    x86_64-win64-vs10
+    x86_64-win64-vs11
+    x86_64-win64-vs12
+    universal-darwin8-gcc
+    universal-darwin9-gcc
+    universal-darwin10-gcc
+    universal-darwin11-gcc
+    universal-darwin12-gcc
+    universal-darwin13-gcc
+    generic-gnu
+
+  The generic-gnu target, in conjunction with the CROSS environment variable,
+  can be used to cross compile architectures that aren't explicitly listed, if
+  the toolchain is a cross GNU (gcc/binutils) toolchain. Other POSIX toolchains
+  will likely work as well. For instance, to build using the mipsel-linux-uclibc
+  toolchain, the following command could be used (note, POSIX SH syntax, adapt
+  to your shell as necessary):
+
+    $ CROSS=mipsel-linux-uclibc- ../libvpx/configure
+
+  In addition, the executables to be invoked can be overridden by specifying the
+  environment variables: CC, AR, LD, AS, STRIP, NM. Additional flags can be
+  passed to these executables with CFLAGS, LDFLAGS, and ASFLAGS.
+
+  5. Configuration errors
+  If the configuration step fails, the first step is to look in the error log.
+  This defaults to config.log. This should give a good indication of what went
+  wrong. If not, contact us for support.
+
+SUPPORT
+  This library is an open source project supported by its community. Please
+  please email webm-discuss@webmproject.org for help.
+

new file mode 100644
--- /dev/null
+++ b/media/libmkv/README_MOZILLA
@@ -0,0 +1,6 @@
+The source from this directory was copied from the libvpx/third_party/libmkv
+git repository using the update.sh script.
+
+The libvpx git repository is: http://git.chromium.org/webm/libvpx.git
+
+The git commit ID used was c5aaf923d80e9f71e0c93d7d99dc1e2f83d7acbf.

new file mode 100644
--- /dev/null
+++ b/media/libmkv/WebMElement.c
@@ -0,0 +1,219 @@
+// Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS.  All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+
+#include "EbmlIDs.h"
+#include "WebMElement.h"
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <time.h>
+
+#define kVorbisPrivateMaxSize  4000
+#define UInt64 uint64_t
+
+void writeHeader(EbmlGlobal *glob) {
+  EbmlLoc start;
+  Ebml_StartSubElement(glob, &start, EBML);
+  Ebml_SerializeUnsigned(glob, EBMLVersion, 1);
+  Ebml_SerializeUnsigned(glob, EBMLReadVersion, 1); // EBML Read Version
+  Ebml_SerializeUnsigned(glob, EBMLMaxIDLength, 4); // EBML Max ID Length
+  Ebml_SerializeUnsigned(glob, EBMLMaxSizeLength, 8); // EBML Max Size Length
+  Ebml_SerializeString(glob, DocType, "webm"); // Doc Type
+  Ebml_SerializeUnsigned(glob, DocTypeVersion, 2); // Doc Type Version
+  Ebml_SerializeUnsigned(glob, DocTypeReadVersion, 2); // Doc Type Read Version
+  Ebml_EndSubElement(glob, &start);
+}
+
+void writeSimpleBlock(EbmlGlobal *glob, unsigned char trackNumber, short timeCode,
+                      int isKeyframe, unsigned char lacingFlag, int discardable,
+                      unsigned char *data, unsigned long dataLength) {
+  unsigned long blockLength = 4 + dataLength;
+  unsigned char flags = 0x00 | (isKeyframe ? 0x80 : 0x00) | (lacingFlag << 1) | discardable;
+  Ebml_WriteID(glob, SimpleBlock);
+  blockLength |= 0x10000000; // TODO check length < 0x0FFFFFFFF
+  Ebml_Serialize(glob, &blockLength, sizeof(blockLength), 4);
+  trackNumber |= 0x80;  // TODO check track nubmer < 128
+  Ebml_Write(glob, &trackNumber, 1);
+  // Ebml_WriteSigned16(glob, timeCode,2); //this is 3 bytes
+  Ebml_Serialize(glob, &timeCode, sizeof(timeCode), 2);
+  flags = 0x00 | (isKeyframe ? 0x80 : 0x00) | (lacingFlag << 1) | discardable;
+  Ebml_Write(glob, &flags, 1);
+  Ebml_Write(glob, data, dataLength);
+}
+
+static UInt64 generateTrackID(unsigned int trackNumber) {
+  UInt64 t = time(NULL) * trackNumber;
+  UInt64 r = rand();
+  r = r << 32;
+  r +=  rand();
+//  UInt64 rval = t ^ r;
+  return t ^ r;
+}
+
+void writeVideoTrack(EbmlGlobal *glob, unsigned int trackNumber, int flagLacing,
+                     char *codecId, unsigned int pixelWidth, unsigned int pixelHeight,
+                     double frameRate) {
+  EbmlLoc start;
+  UInt64 trackID;
+  Ebml_StartSubElement(glob, &start, TrackEntry);
+  Ebml_SerializeUnsigned(glob, TrackNumber, trackNumber);
+  trackID = generateTrackID(trackNumber);
+  Ebml_SerializeUnsigned(glob, TrackUID, trackID);
+  Ebml_SerializeString(glob, CodecName, "VP8");  // TODO shouldn't be fixed
+
+  Ebml_SerializeUnsigned(glob, TrackType, 1); // video is always 1
+  Ebml_SerializeString(glob, CodecID, codecId);
+  {
+    EbmlLoc videoStart;
+    Ebml_StartSubElement(glob, &videoStart, Video);
+    Ebml_SerializeUnsigned(glob, PixelWidth, pixelWidth);
+    Ebml_SerializeUnsigned(glob, PixelHeight, pixelHeight);
+    Ebml_SerializeFloat(glob, FrameRate, frameRate);
+    Ebml_EndSubElement(glob, &videoStart); // Video
+  }
+  Ebml_EndSubElement(glob, &start); // Track Entry
+}
+void writeAudioTrack(EbmlGlobal *glob, unsigned int trackNumber, int flagLacing,
+                     char *codecId, double samplingFrequency, unsigned int channels,
+                     unsigned char *private, unsigned long privateSize) {
+  EbmlLoc start;
+  UInt64 trackID;
+  Ebml_StartSubElement(glob, &start, TrackEntry);
+  Ebml_SerializeUnsigned(glob, TrackNumber, trackNumber);
+  trackID = generateTrackID(trackNumber);
+  Ebml_SerializeUnsigned(glob, TrackUID, trackID);
+  Ebml_SerializeUnsigned(glob, TrackType, 2); // audio is always 2
+  // I am using defaults for thesed required fields
+  /*  Ebml_SerializeUnsigned(glob, FlagEnabled, 1);
+      Ebml_SerializeUnsigned(glob, FlagDefault, 1);
+      Ebml_SerializeUnsigned(glob, FlagForced, 1);
+      Ebml_SerializeUnsigned(glob, FlagLacing, flagLacing);*/
+  Ebml_SerializeString(glob, CodecID, codecId);
+  Ebml_SerializeData(glob, CodecPrivate, private, privateSize);
+
+  Ebml_SerializeString(glob, CodecName, "VORBIS");  // fixed for now
+  {
+    EbmlLoc AudioStart;
+    Ebml_StartSubElement(glob, &AudioStart, Audio);
+    Ebml_SerializeFloat(glob, SamplingFrequency, samplingFrequency);
+    Ebml_SerializeUnsigned(glob, Channels, channels);
+    Ebml_EndSubElement(glob, &AudioStart);
+  }
+  Ebml_EndSubElement(glob, &start);
+}
+void writeSegmentInformation(EbmlGlobal *ebml, EbmlLoc *startInfo, unsigned long timeCodeScale, double duration) {
+  Ebml_StartSubElement(ebml, startInfo, Info);
+  Ebml_SerializeUnsigned(ebml, TimecodeScale, timeCodeScale);
+  Ebml_SerializeFloat(ebml, Segment_Duration, duration * 1000.0); // Currently fixed to using milliseconds
+  Ebml_SerializeString(ebml, 0x4D80, "QTmuxingAppLibWebM-0.0.1");
+  Ebml_SerializeString(ebml, 0x5741, "QTwritingAppLibWebM-0.0.1");
+  Ebml_EndSubElement(ebml, startInfo);
+}
+
+/*
+void Mkv_InitializeSegment(Ebml& ebml_out, EbmlLoc& ebmlLoc)
+{
+    Ebml_StartSubElement(ebml_out, ebmlLoc, 0x18538067);
+}
+
+void Mkv_InitializeSeek(Ebml& ebml_out, EbmlLoc& ebmlLoc)
+{
+    Ebml_StartSubElement(ebml_out, ebmlLoc, 0x114d9b74);
+}
+void Mkv_WriteSeekInformation(Ebml& ebml_out, SeekStruct& seekInformation)
+{
+    EbmlLoc ebmlLoc;
+    Ebml_StartSubElement(ebml_out, ebmlLoc, 0x4dbb);
+    Ebml_SerializeString(ebml_out, 0x53ab, seekInformation.SeekID);
+    Ebml_SerializeUnsigned(ebml_out, 0x53ac, seekInformation.SeekPosition);
+    Ebml_EndSubElement(ebml_out, ebmlLoc);
+}
+
+void Mkv_WriteSegmentInformation(Ebml& ebml_out, SegmentInformationStruct& segmentInformation)
+{
+    Ebml_SerializeUnsigned(ebml_out, 0x73a4, segmentInformation.segmentUID);
+    if (segmentInformation.filename != 0)
+        Ebml_SerializeString(ebml_out, 0x7384, segmentInformation.filename);
+    Ebml_SerializeUnsigned(ebml_out, 0x2AD7B1, segmentInformation.TimecodeScale);
+    Ebml_SerializeUnsigned(ebml_out, 0x4489, segmentInformation.Duration);
+    // TODO date
+    Ebml_SerializeWString(ebml_out, 0x4D80, L"MKVMUX");
+    Ebml_SerializeWString(ebml_out, 0x5741, segmentInformation.WritingApp);
+}
+
+void Mkv_InitializeTrack(Ebml& ebml_out, EbmlLoc& ebmlLoc)
+{
+    Ebml_StartSubElement(ebml_out, ebmlLoc, 0x1654AE6B);
+}
+
+static void Mkv_WriteGenericTrackData(Ebml& ebml_out, TrackStruct& track)
+{
+    Ebml_SerializeUnsigned(ebml_out, 0xD7, track.TrackNumber);
+    Ebml_SerializeUnsigned(ebml_out, 0x73C5, track.TrackUID);
+    Ebml_SerializeUnsigned(ebml_out, 0x83, track.TrackType);
+    Ebml_SerializeUnsigned(ebml_out, 0xB9, track.FlagEnabled ? 1 :0);
+    Ebml_SerializeUnsigned(ebml_out, 0x88, track.FlagDefault ? 1 :0);
+    Ebml_SerializeUnsigned(ebml_out, 0x55AA, track.FlagForced ? 1 :0);
+    if (track.Language != 0)
+        Ebml_SerializeString(ebml_out, 0x22B59C, track.Language);
+    if (track.CodecID != 0)
+        Ebml_SerializeString(ebml_out, 0x86, track.CodecID);
+    if (track.CodecPrivate != 0)
+        Ebml_SerializeData(ebml_out, 0x63A2, track.CodecPrivate, track.CodecPrivateLength);
+    if (track.CodecName != 0)
+        Ebml_SerializeWString(ebml_out, 0x258688, track.CodecName);
+}
+
+void Mkv_WriteVideoTrack(Ebml& ebml_out, TrackStruct & track, VideoTrackStruct& video)
+{
+    EbmlLoc trackHeadLoc, videoHeadLoc;
+    Ebml_StartSubElement(ebml_out, trackHeadLoc, 0xAE);  // start Track
+    Mkv_WriteGenericTrackData(ebml_out, track);
+    Ebml_StartSubElement(ebml_out, videoHeadLoc, 0xE0);  // start Video
+    Ebml_SerializeUnsigned(ebml_out, 0x9A, video.FlagInterlaced ? 1 :0);
+    Ebml_SerializeUnsigned(ebml_out, 0xB0, video.PixelWidth);
+    Ebml_SerializeUnsigned(ebml_out, 0xBA, video.PixelHeight);
+    Ebml_SerializeUnsigned(ebml_out, 0x54B0, video.PixelDisplayWidth);
+    Ebml_SerializeUnsigned(ebml_out, 0x54BA, video.PixelDisplayHeight);
+    Ebml_SerializeUnsigned(ebml_out, 0x54B2, video.displayUnit);
+    Ebml_SerializeFloat(ebml_out, 0x2383E3, video.FrameRate);
+    Ebml_EndSubElement(ebml_out, videoHeadLoc);
+    Ebml_EndSubElement(ebml_out, trackHeadLoc);
+
+}
+
+void Mkv_WriteAudioTrack(Ebml& ebml_out, TrackStruct & track, AudioTrackStruct& video)
+{
+    EbmlLoc trackHeadLoc, audioHeadLoc;
+    Ebml_StartSubElement(ebml_out, trackHeadLoc, 0xAE);
+    Mkv_WriteGenericTrackData(ebml_out, track);
+    Ebml_StartSubElement(ebml_out, audioHeadLoc, 0xE0);  // start Audio
+    Ebml_SerializeFloat(ebml_out, 0xB5, video.SamplingFrequency);
+    Ebml_SerializeUnsigned(ebml_out, 0x9F, video.Channels);
+    Ebml_SerializeUnsigned(ebml_out, 0x6264, video.BitDepth);
+    Ebml_EndSubElement(ebml_out, audioHeadLoc); // end audio
+    Ebml_EndSubElement(ebml_out, trackHeadLoc);
+}
+
+void Mkv_WriteEbmlClusterHead(Ebml& ebml_out,  EbmlLoc& ebmlLoc, ClusterHeadStruct & clusterHead)
+{
+    Ebml_StartSubElement(ebml_out, ebmlLoc, 0x1F43B675);
+    Ebml_SerializeUnsigned(ebml_out, 0x6264, clusterHead.TimeCode);
+}
+
+void Mkv_WriteSimpleBlockHead(Ebml& ebml_out,  EbmlLoc& ebmlLoc, SimpleBlockStruct& block)
+{
+    Ebml_StartSubElement(ebml_out, ebmlLoc, 0xA3);
+    Ebml_Write1UInt(ebml_out, block.TrackNumber);
+    Ebml_WriteSigned16(ebml_out,block.TimeCode);
+    unsigned char flags = 0x00 | (block.iskey ? 0x80:0x00) | (block.lacing << 1) | block.discardable;
+    Ebml_Write1UInt(ebml_out, flags);  // TODO this may be the wrong function
+    Ebml_Serialize(ebml_out, block.data, block.dataLength);
+    Ebml_EndSubElement(ebml_out,ebmlLoc);
+}
+*/

new file mode 100644
--- /dev/null
+++ b/media/libmkv/WebMElement.h
@@ -0,0 +1,37 @@
+// Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree. An additional intellectual property rights grant can be found
+// in the file PATENTS.  All contributing project authors may
+// be found in the AUTHORS file in the root of the source tree.
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifndef MKV_CONTEXT_HPP
+#define MKV_CONTEXT_HPP 1
+
+#include "EbmlWriter.h"
+
+// these are helper functions
+void writeHeader(EbmlGlobal *ebml);
+void writeSegmentInformation(EbmlGlobal *ebml, EbmlLoc *startInfo, unsigned long timeCodeScale, double duration);
+// this function is a helper only, it assumes a lot of defaults
+void writeVideoTrack(EbmlGlobal *ebml, unsigned int trackNumber, int flagLacing,
+                     char *codecId, unsigned int pixelWidth, unsigned int pixelHeight,
+                     double frameRate);
+void writeAudioTrack(EbmlGlobal *glob, unsigned int trackNumber, int flagLacing,
+                     char *codecId, double samplingFrequency, unsigned int channels,
+                     unsigned char *private_, unsigned long privateSize);
+
+void writeSimpleBlock(EbmlGlobal *ebml, unsigned char trackNumber, short timeCode,
+                      int isKeyframe, unsigned char lacingFlag, int discardable,
+                      unsigned char *data, unsigned long dataLength);
+
+#endif
+
+#ifdef __cplusplus
+}
+#endif

new file mode 100644
--- /dev/null
+++ b/media/libmkv/gecko_fix.patch
@@ -0,0 +1,133 @@
+diff --git a/EbmlBufferWriter.h b/EbmlBufferWriter.h
+index c135f29..d5116ce 100644
+--- a/EbmlBufferWriter.h
++++ b/EbmlBufferWriter.h
+@@ -11,6 +11,9 @@ typedef struct {
+   unsigned int offset;
+ } EbmlGlobal;
+ 
++void Ebml_Write(EbmlGlobal *glob, const void *buffer_in, unsigned long len);
++void Ebml_Serialize(EbmlGlobal *glob, const void *buffer_in,
++                    int buffer_size, unsigned long len);
+ void Ebml_StartSubElement(EbmlGlobal *glob, EbmlLoc *ebmlLoc, unsigned long class_id);
+ void Ebml_EndSubElement(EbmlGlobal *glob,  EbmlLoc *ebmlLoc);
+ 
+diff --git a/EbmlIDs.h b/EbmlIDs.h
+index 44d4385..3b5da19 100644
+--- a/EbmlIDs.h
++++ b/EbmlIDs.h
+@@ -119,7 +119,7 @@ enum mkv {
+   /* video */
+   Video = 0xE0,
+   FlagInterlaced = 0x9A,
+-  StereoMode = 0x53B8,
++  WEBM_StereoMode = 0x53B8,
+   AlphaMode = 0x53C0,
+   PixelWidth = 0xB0,
+   PixelHeight = 0xBA,
+diff --git a/EbmlWriter.c b/EbmlWriter.c
+index ebefc1a..087e817 100644
+--- a/EbmlWriter.c
++++ b/EbmlWriter.c
+@@ -12,6 +12,7 @@
+ #include <wchar.h>
+ #include <string.h>
+ #include <limits.h>
++#include "EbmlBufferWriter.h"
+ #if defined(_MSC_VER)
+ #define LITERALU64(n) n
+ #else
+diff --git a/EbmlWriter.h b/EbmlWriter.h
+index a0a848b..3aee2b3 100644
+--- a/EbmlWriter.h
++++ b/EbmlWriter.h
+@@ -7,10 +7,16 @@
+  *  in the file PATENTS.  All contributing project authors may
+  *  be found in the AUTHORS file in the root of the source tree.
+  */
++
++#ifdef __cplusplus
++extern "C" {
++#endif
++
+ #ifndef EBMLWRITER_HPP
+ #define EBMLWRITER_HPP
+ #include <stddef.h>
+ #include "vpx/vpx_integer.h"
++#include "EbmlBufferWriter.h"
+ 
+ /* note: you must define write and serialize functions as well as your own
+  * EBML_GLOBAL
+@@ -18,9 +24,9 @@
+  * These functions MUST be implemented
+  */
+ 
+-typedef struct EbmlGlobal EbmlGlobal;
+-void  Ebml_Serialize(EbmlGlobal *glob, const void *, int, unsigned long);
+-void  Ebml_Write(EbmlGlobal *glob, const void *, unsigned long);
++// typedef struct EbmlGlobal EbmlGlobal;
++// void  Ebml_Serialize(EbmlGlobal *glob, const void *, int, unsigned long);
++// void  Ebml_Write(EbmlGlobal *glob, const void *, unsigned long);
+ 
+ /*****/
+ 
+@@ -41,3 +47,7 @@ void Ebml_SerializeData(EbmlGlobal *glob, unsigned long class_id, unsigned char
+ void Ebml_WriteVoid(EbmlGlobal *glob, unsigned long vSize);
+ /* TODO need date function */
+ #endif
++
++#ifdef __cplusplus
++}
++#endif
+diff --git a/WebMElement.c b/WebMElement.c
+index 02eefa4..0d5056d 100644
+--- a/WebMElement.c
++++ b/WebMElement.c
+@@ -6,8 +6,6 @@
+ // in the file PATENTS.  All contributing project authors may
+ // be found in the AUTHORS file in the root of the source tree.
+ 
+-
+-#include "EbmlBufferWriter.h"
+ #include "EbmlIDs.h"
+ #include "WebMElement.h"
+ #include <stdio.h>
+diff --git a/WebMElement.h b/WebMElement.h
+index d9ad0a0..987582a 100644
+--- a/WebMElement.h
++++ b/WebMElement.h
+@@ -6,10 +6,15 @@
+ // in the file PATENTS.  All contributing project authors may
+ // be found in the AUTHORS file in the root of the source tree.
+ 
++#ifdef __cplusplus
++extern "C" {
++#endif
+ 
+ #ifndef MKV_CONTEXT_HPP
+ #define MKV_CONTEXT_HPP 1
+ 
++#include "EbmlWriter.h"
++
+ void writeSimpleBock(EbmlGlobal *ebml, unsigned char trackNumber, unsigned short timeCode,
+                      int isKeyframe, unsigned char lacingFlag, int  discardable,
+                      unsigned char *data, unsigned long dataLength);
+@@ -24,12 +29,14 @@ void writeVideoTrack(EbmlGlobal *ebml, unsigned int trackNumber, int flagLacing,
+                      double frameRate);
+ void writeAudioTrack(EbmlGlobal *glob, unsigned int trackNumber, int flagLacing,
+                      char *codecId, double samplingFrequency, unsigned int channels,
+-                     unsigned char *private, unsigned long privateSize);
++                     unsigned char *private_, unsigned long privateSize);
+ 
+ void writeSimpleBlock(EbmlGlobal *ebml, unsigned char trackNumber, short timeCode,
+                       int isKeyframe, unsigned char lacingFlag, int discardable,
+                       unsigned char *data, unsigned long dataLength);
+ 
++#endif
+ 
+-
+-#endif
+\ No newline at end of file
++#ifdef __cplusplus
++}
++#endif

new file mode 100644
--- /dev/null
+++ b/media/libmkv/moz.build
@@ -0,0 +1,27 @@
+# -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+EXPORTS.libmkv += [
+    'EbmlBufferWriter.h',
+    'EbmlIDs.h',
+    'EbmlWriter.h',
+    'WebMElement.h',
+]
+
+UNIFIED_SOURCES += [
+]
+
+# These files can't be unified because of function redefinitions.
+SOURCES += [
+    'EbmlBufferWriter.c',
+    'EbmlWriter.c',
+    'WebMElement.c',
+]
+
+if CONFIG['GKMEDIAS_SHARED_LIBRARY']:
+    NO_VISIBILITY_FLAGS = True
+
+FINAL_LIBRARY = 'gkmedias'

new file mode 100644
--- /dev/null
+++ b/media/libmkv/source_fix.patch
@@ -0,0 +1,193 @@
+diff --git a/EbmlBufferWriter.c b/EbmlBufferWriter.c
+index 574e478..8c26e80 100644
+--- a/EbmlBufferWriter.c
++++ b/EbmlBufferWriter.c
+@@ -8,6 +8,31 @@
+ #include <wchar.h>
+ #include <string.h>
+ 
++void
++Ebml_Serialize(EbmlGlobal *glob, const void *buffer_in, int buffer_size, unsigned long len)
++{
++  /* buffer_size:
++   * 1 - int8_t;
++   * 2 - int16_t;
++   * 3 - int32_t;
++   * 4 - int64_t;
++   */
++  long i;
++  for(i = len-1; i >= 0; i--) {
++    unsigned char x;
++    if (buffer_size == 1) {
++      x = (char)(*(const int8_t *)buffer_in >> (i * 8));
++	} else if (buffer_size == 2) {
++      x = (char)(*(const int16_t *)buffer_in >> (i * 8));
++	} else if (buffer_size == 4) {
++      x = (char)(*(const int32_t *)buffer_in >> (i * 8));
++	} else if (buffer_size == 8) {
++      x = (char)(*(const int64_t *)buffer_in >> (i * 8));
++	}
++    Ebml_Write(glob, &x, 1);
++  }
++}
++
+ void Ebml_Write(EbmlGlobal *glob, const void *buffer_in, unsigned long len) {
+   unsigned char *src = glob->buf;
+   src += glob->offset;
+@@ -19,12 +44,12 @@ static void _Serialize(EbmlGlobal *glob, const unsigned char *p, const unsigned
+   while (q != p) {
+     --q;
+ 
+-    unsigned long cbWritten;
+     memcpy(&(glob->buf[glob->offset]), q, 1);
+     glob->offset++;
+   }
+ }
+ 
++/*
+ void Ebml_Serialize(EbmlGlobal *glob, const void *buffer_in, unsigned long len) {
+   // assert(buf);
+ 
+@@ -33,22 +58,22 @@ void Ebml_Serialize(EbmlGlobal *glob, const void *buffer_in, unsigned long len)
+ 
+   _Serialize(glob, p, q);
+ }
+-
++*/
+ 
+ void Ebml_StartSubElement(EbmlGlobal *glob, EbmlLoc *ebmlLoc, unsigned long class_id) {
++  unsigned long long unknownLen = 0x01FFFFFFFFFFFFFFLL;
+   Ebml_WriteID(glob, class_id);
+   ebmlLoc->offset = glob->offset;
+   // todo this is always taking 8 bytes, this may need later optimization
+-  unsigned long long unknownLen =  0x01FFFFFFFFFFFFFFLLU;
+-  Ebml_Serialize(glob, (void *)&unknownLen, 8); // this is a key that says lenght unknown
++  Ebml_Serialize(glob, (void *)&unknownLen,sizeof(unknownLen), 8); // this is a key that says lenght unknown
+ }
+ 
+ void Ebml_EndSubElement(EbmlGlobal *glob, EbmlLoc *ebmlLoc) {
+   unsigned long long size = glob->offset - ebmlLoc->offset - 8;
+   unsigned long long curOffset = glob->offset;
+   glob->offset = ebmlLoc->offset;
+-  size |=  0x0100000000000000LLU;
+-  Ebml_Serialize(glob, &size, 8);
++  size |=  0x0100000000000000LL;
++  Ebml_Serialize(glob, &size,sizeof(size), 8);
+   glob->offset = curOffset;
+ }
+ 
+diff --git a/EbmlBufferWriter.h b/EbmlBufferWriter.h
+index acd5c2a..c135f29 100644
+--- a/EbmlBufferWriter.h
++++ b/EbmlBufferWriter.h
+@@ -11,9 +11,7 @@ typedef struct {
+   unsigned int offset;
+ } EbmlGlobal;
+ 
+-
+ void Ebml_StartSubElement(EbmlGlobal *glob, EbmlLoc *ebmlLoc, unsigned long class_id);
+ void Ebml_EndSubElement(EbmlGlobal *glob,  EbmlLoc *ebmlLoc);
+ 
+-
+ #endif
+diff --git a/EbmlWriter.c b/EbmlWriter.c
+index 27cfe86..ebefc1a 100644
+--- a/EbmlWriter.c
++++ b/EbmlWriter.c
+@@ -74,6 +74,13 @@ void Ebml_WriteID(EbmlGlobal *glob, unsigned long class_id) {
+   Ebml_Serialize(glob, (void *)&class_id, sizeof(class_id), len);
+ }
+ 
++void Ebml_SerializeUnsigned32(EbmlGlobal *glob, unsigned long class_id, uint32_t ui) {
++  unsigned char sizeSerialized = 8 | 0x80;
++  Ebml_WriteID(glob, class_id);
++  Ebml_Serialize(glob, &sizeSerialized, sizeof(sizeSerialized), 1);
++  Ebml_Serialize(glob, &ui, sizeof(ui), 4);
++}
++
+ void Ebml_SerializeUnsigned64(EbmlGlobal *glob, unsigned long class_id, uint64_t ui) {
+   unsigned char sizeSerialized = 8 | 0x80;
+   Ebml_WriteID(glob, class_id);
+diff --git a/EbmlWriter.h b/EbmlWriter.h
+index b94f757..a0a848b 100644
+--- a/EbmlWriter.h
++++ b/EbmlWriter.h
+@@ -28,6 +28,7 @@ void Ebml_WriteLen(EbmlGlobal *glob, int64_t val);
+ void Ebml_WriteString(EbmlGlobal *glob, const char *str);
+ void Ebml_WriteUTF8(EbmlGlobal *glob, const wchar_t *wstr);
+ void Ebml_WriteID(EbmlGlobal *glob, unsigned long class_id);
++void Ebml_SerializeUnsigned32(EbmlGlobal *glob, unsigned long class_id, uint32_t ui);
+ void Ebml_SerializeUnsigned64(EbmlGlobal *glob, unsigned long class_id, uint64_t ui);
+ void Ebml_SerializeUnsigned(EbmlGlobal *glob, unsigned long class_id, unsigned long ui);
+ void Ebml_SerializeBinary(EbmlGlobal *glob, unsigned long class_id, unsigned long ui);
+diff --git a/WebMElement.c b/WebMElement.c
+index 2f79a3c..02eefa4 100644
+--- a/WebMElement.c
++++ b/WebMElement.c
+@@ -11,8 +11,12 @@
+ #include "EbmlIDs.h"
+ #include "WebMElement.h"
+ #include <stdio.h>
++#include <stdint.h>
++#include <stdlib.h>
++#include <time.h>
+ 
+ #define kVorbisPrivateMaxSize  4000
++#define UInt64 uint64_t
+ 
+ void writeHeader(EbmlGlobal *glob) {
+   EbmlLoc start;
+@@ -30,15 +34,16 @@ void writeHeader(EbmlGlobal *glob) {
+ void writeSimpleBlock(EbmlGlobal *glob, unsigned char trackNumber, short timeCode,
+                       int isKeyframe, unsigned char lacingFlag, int discardable,
+                       unsigned char *data, unsigned long dataLength) {
+-  Ebml_WriteID(glob, SimpleBlock);
+   unsigned long blockLength = 4 + dataLength;
++  unsigned char flags = 0x00 | (isKeyframe ? 0x80 : 0x00) | (lacingFlag << 1) | discardable;
++  Ebml_WriteID(glob, SimpleBlock);
+   blockLength |= 0x10000000; // TODO check length < 0x0FFFFFFFF
+   Ebml_Serialize(glob, &blockLength, sizeof(blockLength), 4);
+   trackNumber |= 0x80;  // TODO check track nubmer < 128
+   Ebml_Write(glob, &trackNumber, 1);
+   // Ebml_WriteSigned16(glob, timeCode,2); //this is 3 bytes
+   Ebml_Serialize(glob, &timeCode, sizeof(timeCode), 2);
+-  unsigned char flags = 0x00 | (isKeyframe ? 0x80 : 0x00) | (lacingFlag << 1) | discardable;
++  flags = 0x00 | (isKeyframe ? 0x80 : 0x00) | (lacingFlag << 1) | discardable;
+   Ebml_Write(glob, &flags, 1);
+   Ebml_Write(glob, data, dataLength);
+ }
+@@ -48,17 +53,18 @@ static UInt64 generateTrackID(unsigned int trackNumber) {
+   UInt64 r = rand();
+   r = r << 32;
+   r +=  rand();
+-  UInt64 rval = t ^ r;
+-  return rval;
++//  UInt64 rval = t ^ r;
++  return t ^ r;
+ }
+ 
+ void writeVideoTrack(EbmlGlobal *glob, unsigned int trackNumber, int flagLacing,
+                      char *codecId, unsigned int pixelWidth, unsigned int pixelHeight,
+                      double frameRate) {
+   EbmlLoc start;
++  UInt64 trackID;
+   Ebml_StartSubElement(glob, &start, TrackEntry);
+   Ebml_SerializeUnsigned(glob, TrackNumber, trackNumber);
+-  UInt64 trackID = generateTrackID(trackNumber);
++  trackID = generateTrackID(trackNumber);
+   Ebml_SerializeUnsigned(glob, TrackUID, trackID);
+   Ebml_SerializeString(glob, CodecName, "VP8");  // TODO shouldn't be fixed
+ 
+@@ -78,9 +84,10 @@ void writeAudioTrack(EbmlGlobal *glob, unsigned int trackNumber, int flagLacing,
+                      char *codecId, double samplingFrequency, unsigned int channels,
+                      unsigned char *private, unsigned long privateSize) {
+   EbmlLoc start;
++  UInt64 trackID;
+   Ebml_StartSubElement(glob, &start, TrackEntry);
+   Ebml_SerializeUnsigned(glob, TrackNumber, trackNumber);
+-  UInt64 trackID = generateTrackID(trackNumber);
++  trackID = generateTrackID(trackNumber);
+   Ebml_SerializeUnsigned(glob, TrackUID, trackID);
+   Ebml_SerializeUnsigned(glob, TrackType, 2); // audio is always 2
+   // I am using defaults for thesed required fields
+

new file mode 100644
--- /dev/null
+++ b/media/libmkv/update.sh
@@ -0,0 +1,33 @@
+# Usage: sh update.sh <upstream_src_directory>
+set -e
+echo "copy source from libvpx"
+
+cp $1/third_party/libmkv/EbmlBufferWriter.c .
+cp $1/third_party/libmkv/WebMElement.c .
+cp $1/third_party/libmkv/EbmlWriter.c .
+cp $1/third_party/libmkv/EbmlWriter.h .
+cp $1/third_party/libmkv/EbmlBufferWriter.h .
+cp $1/third_party/libmkv/WebMElement.h .
+cp $1/third_party/libmkv/EbmlIDs.h .
+
+cp $1/LICENSE .
+cp $1/README .
+cp $1/AUTHORS .
+if [ -d $1/.git ]; then
+  rev=$(cd $1 && git rev-parse --verify HEAD)
+  dirty=$(cd $1 && git diff-index --name-only HEAD)
+fi
+
+if [ -n "$rev" ]; then
+  version=$rev
+  if [ -n "$dirty" ]; then
+    version=$version-dirty
+    echo "WARNING: updating from a dirty git repository."
+  fi
+  sed -i.bak -e "/The git commit ID used was/ s/[0-9a-f]\{40\}\(-dirty\)\{0,1\}\./$version./" README_MOZILLA
+  rm README_MOZILLA.bak
+else
+  echo "Remember to update README_MOZILLA with the version details."
+fi
+
+echo "please apply source_fix.patch and gecko_fix.patch"