dom/media/BitWriter.h
author Mike Hommey <mh+mozilla@glandium.org>
Fri, 11 Jan 2019 16:01:15 +0000
changeset 453570 daf50f25895db073e44d50fecf2e4f6fe873865d
parent 446960 0ceae9db9ec0be18daa1a279511ad305723185d4
permissions -rw-r--r--
Bug 1519307 - Add a new project to build useful parts of breakpad independently. r=froydnj With `ac_add_options --enable-project=tools/crashreporter` in a mozconfig, `./mach build` builds minidump_stackwalk, dump_syms and fileid. One caveat is that due to limitation in how the build system works currently, it's cumbersome to keep dump_syms as a host program for Gecko, and to make it a target program for this project. For now, keep it as a host program. We're not going to use it on automation, but it's still convenient to have for quick local builds (I've had to resort to awful hacks downstream). Differential Revision: https://phabricator.services.mozilla.com/D16299

/* 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 BIT_WRITER_H_
#define BIT_WRITER_H_

#include "mozilla/RefPtr.h"

namespace mozilla {

class MediaByteBuffer;

class BitWriter {
 public:
  explicit BitWriter(MediaByteBuffer* aBuffer);
  virtual ~BitWriter();
  void WriteBits(uint64_t aValue, size_t aBits);
  void WriteBit(bool aValue) { WriteBits(aValue, 1); }
  void WriteU8(uint8_t aValue) { WriteBits(aValue, 8); }
  void WriteU32(uint32_t aValue) { WriteBits(aValue, 32); }
  void WriteU64(uint64_t aValue) { WriteBits(aValue, 64); }

  // Write unsigned integer into Exp-Golomb-coded. 2^32-2 at most
  void WriteUE(uint32_t aValue);

  // Write RBSP trailing bits.
  void CloseWithRbspTrailing();

  // Return the number of bits written so far;
  size_t BitCount() const { return mPosition * 8 + mBitIndex; }

 private:
  RefPtr<MediaByteBuffer> mBuffer;
  size_t mPosition = 0;
  uint8_t mBitIndex = 0;
};

}  // namespace mozilla

#endif  // BIT_WRITER_H_