dom/media/MediaPrefs.h
author Chris Pearce <cpearce@mozilla.com>
Fri, 19 Aug 2016 21:34:42 +1200
changeset 350216 7852ac7e74faf5a637189437ce0a9a7f39e6292c
parent 347954 d4ec1b2cf832673078935f9e57cff6061c1bec16
child 350692 c216304c306bda09e8b8766f692885fa378ddb3c
permissions -rw-r--r--
Bug 1295630 - Provide a way for A/V sync to be ruined, so talos can test compositor throughput by painting expired frames. r=mattwoodrow, a=ritu In bug 1258870 I changed the media code so that we dropped all late video frames. Without this, our A/V sync was broken when the decode was struggling to keep up, and we weren't reporting dropped frames when the decode couldn't keep up, and so players couldn't adapt to a bitrate which the decode could keep up on. However, dropping all late frames broke talos tests which relied on the old behaviour of us rendering video frames that were late. So this patch adds a pref to cause the frame dropping code to not drop the last frame in the queue, so there will always be something for the compositor to composit. This means talos will once again be able to test how fast it can composit frames that aren't supposed to be drawn. The pref is media.ruin-av-sync.enabled. It defaults to false. MozReview-Commit-ID: J3VvpzoDRmI

/* -*- Mode: C++; tab-width: 20; 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 MEDIA_PREFS_H
#define MEDIA_PREFS_H

#ifdef MOZ_WIDGET_ANDROID
#include "AndroidBridge.h"
#endif

#include "mozilla/Atomics.h"

// First time MediaPrefs::GetSingleton() needs to be called on the main thread,
// before any of the methods accessing the values are used, but after
// the Preferences system has been initialized.

// The static methods to access the preference value are safe to call
// from any thread after that first call.

// To register a preference, you need to add a line in this file using
// the DECL_MEDIA_PREF macro.
//
// For example this line in the .h:
//   DECL_MEDIA_PREF("media.resampling.enabled",AudioSinkResampling,bool,false);
// means that you can call
//   const bool& var = MediaPrefs::AudioSinkResampling();
// from any thread, you will get the most up to date preference value of
// "media.resampling.enabled".  If the value is not set, the default would be
// false.

#define DECL_MEDIA_PREF(Pref, Name, Type, Default)                            \
public:                                                                       \
static const Type& Name() { MOZ_ASSERT(SingletonExists()); return GetSingleton().mPref##Name.mValue; } \
private:                                                                      \
static const char* Get##Name##PrefName() { return Pref; }                     \
static StripAtomic<Type> Get##Name##PrefDefault() { return Default; }         \
PrefTemplate<Type, Get##Name##PrefDefault, Get##Name##PrefName> mPref##Name

// Custom Definitions.
#define GMP_DEFAULT_ASYNC_SHUTDOWN_TIMEOUT 3000
#define SUSPEND_BACKGROUND_VIDEO_DELAY_MS 10000
#define TEST_PREFERENCE_FAKE_RECOGNITION_SERVICE "media.webspeech.test.fake_recognition_service"

namespace mozilla {

template<class T> class StaticAutoPtr;

class MediaPrefs final
{
  typedef Atomic<uint32_t, Relaxed> AtomicUint32;

  template <typename T>
  struct StripAtomicImpl {
    typedef T Type;
  };

  template <typename T, MemoryOrdering Order>
  struct StripAtomicImpl<Atomic<T, Order>> {
    typedef T Type;
  };

  template <typename T>
  using StripAtomic = typename StripAtomicImpl<T>::Type;

private:
  // Since we cannot use const char*, use a function that returns it.
  template <class T, StripAtomic<T> Default(), const char* Pref()>
  class PrefTemplate
  {
  public:
    PrefTemplate()
    : mValue(Default())
    {
      Register(Pref());
    }
    T mValue;
  private:
    void Register(const char* aPreference)
    {
      AssertMainThread();
      PrefAddVarCache(&mValue, aPreference, mValue);
    }
  };

  // This is where DECL_MEDIA_PREF for each of the preferences should go.

  // AudioSink
  DECL_MEDIA_PREF("accessibility.monoaudio.enable",           MonoAudio, bool, false);
  DECL_MEDIA_PREF("media.resampling.enabled",                 AudioSinkResampling, bool, false);
  DECL_MEDIA_PREF("media.resampling.rate",                    AudioSinkResampleRate, uint32_t, 48000);
  DECL_MEDIA_PREF("media.forcestereo.enabled",                AudioSinkForceStereo, bool, true);

  // VideoSink
  DECL_MEDIA_PREF("media.ruin-av-sync.enabled",               RuinAvSync, bool, false);

  // PlatformDecoderModule
  DECL_MEDIA_PREF("media.apple.forcevda",                     AppleForceVDA, bool, false);
  DECL_MEDIA_PREF("media.gmp.insecure.allow",                 GMPAllowInsecure, bool, false);
  DECL_MEDIA_PREF("media.gmp.async-shutdown-timeout",         GMPAsyncShutdownTimeout, uint32_t, GMP_DEFAULT_ASYNC_SHUTDOWN_TIMEOUT);
  DECL_MEDIA_PREF("media.eme.enabled",                        EMEEnabled, bool, false);
  DECL_MEDIA_PREF("media.use-blank-decoder",                  PDMUseBlankDecoder, bool, false);
#ifdef MOZ_GONK_MEDIACODEC
  DECL_MEDIA_PREF("media.gonk.enabled",                       PDMGonkDecoderEnabled, bool, true);
#endif
#ifdef MOZ_WIDGET_ANDROID
  DECL_MEDIA_PREF("media.android-media-codec.enabled",        PDMAndroidMediaCodecEnabled, bool, false);
  DECL_MEDIA_PREF("media.android-media-codec.preferred",      PDMAndroidMediaCodecPreferred, bool, false);
#endif
#ifdef MOZ_FFMPEG
  DECL_MEDIA_PREF("media.ffmpeg.enabled",                     PDMFFmpegEnabled, bool, true);
#endif
#ifdef MOZ_FFVPX
  DECL_MEDIA_PREF("media.ffvpx.enabled",                      PDMFFVPXEnabled, bool, true);
#endif
#ifdef XP_WIN
  DECL_MEDIA_PREF("media.wmf.enabled",                        PDMWMFEnabled, bool, true);
  DECL_MEDIA_PREF("media.decoder-doctor.wmf-disabled-is-failure", DecoderDoctorWMFDisabledIsFailure, bool, false);
  DECL_MEDIA_PREF("media.webm.intel_decoder.enabled",         PDMWMFIntelDecoderEnabled, bool, false);
  DECL_MEDIA_PREF("media.wmf.low-latency.enabled",            PDMWMFLowLatencyEnabled, bool, false);
  DECL_MEDIA_PREF("media.wmf.decoder.thread-count",           PDMWMFThreadCount, int32_t, -1);
  DECL_MEDIA_PREF("media.wmf.skip-blacklist",                 PDMWMFSkipBlacklist, bool, false);
  DECL_MEDIA_PREF("media.windows-media-foundation.max-dxva-videos", PDMWMFMaxDXVAVideos, uint32_t, 8);
  DECL_MEDIA_PREF("media.windows-media-foundation.allow-d3d11-dxva", PDMWMFAllowD3D11, bool, true);
#endif
  DECL_MEDIA_PREF("media.decoder.fuzzing.enabled",            PDMFuzzingEnabled, bool, false);
  DECL_MEDIA_PREF("media.decoder.fuzzing.video-output-minimum-interval-ms", PDMFuzzingInterval, uint32_t, 0);
  DECL_MEDIA_PREF("media.decoder.fuzzing.dont-delay-inputexhausted", PDMFuzzingDelayInputExhausted, bool, true);
  DECL_MEDIA_PREF("media.gmp.decoder.enabled",                PDMGMPEnabled, bool, true);
  DECL_MEDIA_PREF("media.gmp.decoder.aac",                    GMPAACPreferred, uint32_t, 0);
  DECL_MEDIA_PREF("media.gmp.decoder.h264",                   GMPH264Preferred, uint32_t, 0);

  // MediaDecoderStateMachine
  DECL_MEDIA_PREF("media.suspend-bkgnd-video.enabled",        MDSMSuspendBackgroundVideoEnabled, bool, false);
  DECL_MEDIA_PREF("media.suspend-bkgnd-video.delay-ms",       MDSMSuspendBackgroundVideoDelay, AtomicUint32, SUSPEND_BACKGROUND_VIDEO_DELAY_MS);

  // WebSpeech
  DECL_MEDIA_PREF("media.webspeech.synth.force_global_queue", WebSpeechForceGlobal, bool, false);
  DECL_MEDIA_PREF("media.webspeech.test.enable",              WebSpeechTestEnabled, bool, false);
  DECL_MEDIA_PREF("media.webspeech.test.fake_fsm_events",     WebSpeechFakeFSMEvents, bool, false);
  DECL_MEDIA_PREF(TEST_PREFERENCE_FAKE_RECOGNITION_SERVICE,   WebSpeechFakeRecognitionService, bool, false);
  DECL_MEDIA_PREF("media.webspeech.recognition.enable",       WebSpeechRecognitionEnabled, bool, false);
  DECL_MEDIA_PREF("media.webspeech.recognition.force_enable", WebSpeechRecognitionForceEnabled, bool, false);

  DECL_MEDIA_PREF("media.num-decode-threads",                 MediaThreadPoolDefaultCount, uint32_t, 4);
  DECL_MEDIA_PREF("media.decoder.limit",                      MediaDecoderLimit, int32_t, MediaDecoderLimitDefault());

public:
  // Manage the singleton:
  static MediaPrefs& GetSingleton();
  static bool SingletonExists();

private:
  template<class T> friend class StaticAutoPtr;
  static StaticAutoPtr<MediaPrefs> sInstance;

  // Default value functions
  static int32_t MediaDecoderLimitDefault()
  {
#ifdef MOZ_WIDGET_ANDROID
    if (AndroidBridge::Bridge() &&
        AndroidBridge::Bridge()->GetAPIVersion() < 18) {
      // Older Android versions have broken support for multiple simultaneous
      // decoders, see bug 1278574.
      return 1;
    }
#endif
    // Otherwise, set no decoder limit.
    return -1;
  }

  // Creating these to avoid having to include Preferences.h in the .h
  static void PrefAddVarCache(bool*, const char*, bool);
  static void PrefAddVarCache(int32_t*, const char*, int32_t);
  static void PrefAddVarCache(uint32_t*, const char*, uint32_t);
  static void PrefAddVarCache(float*, const char*, float);
  static void PrefAddVarCache(AtomicUint32*, const char*, uint32_t);

  static void AssertMainThread();

  MediaPrefs();
  MediaPrefs(const MediaPrefs&) = delete;
  MediaPrefs& operator=(const MediaPrefs&) = delete;
};

#undef DECL_MEDIA_PREF /* Don't need it outside of this file */

} // namespace mozilla

#endif /* MEDIA_PREFS_H */