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// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef MEDIA_MUXERS_WEBM_MUXER_H_
#define MEDIA_MUXERS_WEBM_MUXER_H_
#include <stdint.h>
#include <deque>
#include "base/callback.h"
#include "base/macros.h"
#include "base/numerics/safe_math.h"
#include "base/strings/string_piece.h"
#include "base/threading/thread_checker.h"
#include "base/time/time.h"
#include "media/base/media_export.h"
#include "media/base/video_codecs.h"
#include "third_party/libwebm/source/mkvmuxer.hpp"
namespace gfx {
class Size;
} // namespace gfx
namespace media {
class VideoFrame;
class AudioParameters;
// Adapter class to manage a WebM container [1], a simplified version of a
// Matroska container [2], composed of an EBML header, and a single Segment
// including at least a Track Section and a number of SimpleBlocks each
// containing a single encoded video or audio frame. WebM container has no
// Trailer.
// Clients will push encoded VPx video frames and Opus audio frames one by one
// via OnEncoded{Video|Audio}(). libwebm will eventually ping the WriteDataCB
// passed on contructor with the wrapped encoded data.
// WebmMuxer is designed for use on a single thread.
// [1] http://www.webmproject.org/docs/container/
// [2] http://www.matroska.org/technical/specs/index.html
class MEDIA_EXPORT WebmMuxer : public NON_EXPORTED_BASE(mkvmuxer::IMkvWriter) {
public:
// Callback to be called when WebmMuxer is ready to write a chunk of data,
// either any file header or a SingleBlock.
using WriteDataCB = base::Callback<void(base::StringPiece)>;
// |codec| can be VP8 or VP9 and should coincide with whatever is sent in
// OnEncodedVideo().
WebmMuxer(VideoCodec codec,
bool has_video_,
bool has_audio_,
const WriteDataCB& write_data_callback);
~WebmMuxer() override;
// Functions to add video and audio frames with |encoded_data.data()|
// to WebM Segment.
void OnEncodedVideo(const scoped_refptr<VideoFrame>& video_frame,
scoped_ptr<std::string> encoded_data,
base::TimeTicks timestamp,
bool is_key_frame);
void OnEncodedAudio(const media::AudioParameters& params,
scoped_ptr<std::string> encoded_data,
base::TimeTicks timestamp);
private:
friend class WebmMuxerTest;
// Methods for creating and adding video and audio tracks, called upon
// receiving the first frame of a given Track.
// AddVideoTrack adds |frame_size| and |frame_rate| to the Segment
// info, although individual frames passed to OnEncodedVideo() can have any
// frame size.
void AddVideoTrack(const gfx::Size& frame_size, double frame_rate);
void AddAudioTrack(const media::AudioParameters& params);
// IMkvWriter interface.
mkvmuxer::int32 Write(const void* buf, mkvmuxer::uint32 len) override;
mkvmuxer::int64 Position() const override;
mkvmuxer::int32 Position(mkvmuxer::int64 position) override;
bool Seekable() const override;
void ElementStartNotify(mkvmuxer::uint64 element_id,
mkvmuxer::int64 position) override;
// Helper to simplify saving frames.
void AddFrame(scoped_ptr<std::string> encoded_data,
uint8_t track_index,
base::TimeTicks timestamp,
bool is_key_frame);
// Used to DCHECK that we are called on the correct thread.
base::ThreadChecker thread_checker_;
// Video Codec configured: VP9 if true, otherwise VP8 is used by default.
const bool use_vp9_;
// Caller-side identifiers to interact with |segment_|, initialised upon
// first frame arrival to Add{Video, Audio}Track().
uint8_t video_track_index_;
uint8_t audio_track_index_;
// Origin of times for frame timestamps.
base::TimeTicks first_frame_timestamp_;
base::TimeDelta most_recent_timestamp_;
// TODO(ajose): Change these when support is added for multiple tracks.
// http://crbug.com/528523
const bool has_video_;
const bool has_audio_;
// Callback to dump written data as being called by libwebm.
const WriteDataCB write_data_callback_;
// Rolling counter of the position in bytes of the written goo.
base::CheckedNumeric<mkvmuxer::int64> position_;
// The MkvMuxer active element.
mkvmuxer::Segment segment_;
// Hold on to all encoded video frames to dump them with and when audio is
// received, if expected, since WebM headers can only be written once.
struct EncodedVideoFrame {
EncodedVideoFrame(scoped_ptr<std::string> data,
base::TimeTicks timestamp,
bool is_keyframe);
~EncodedVideoFrame();
scoped_ptr<std::string> data;
base::TimeTicks timestamp;
bool is_keyframe;
private:
DISALLOW_IMPLICIT_CONSTRUCTORS(EncodedVideoFrame);
};
std::deque<scoped_ptr<EncodedVideoFrame>> encoded_frames_queue_;
DISALLOW_COPY_AND_ASSIGN(WebmMuxer);
};
} // namespace media
#endif // MEDIA_MUXERS_WEBM_MUXER_H_
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