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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_FILTERS_LIBWEBM_MUXER_H_
#define MEDIA_FILTERS_LIBWEBM_MUXER_H_
#include <set>
#include "base/callback.h"
#include "base/gtest_prod_util.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 "third_party/libwebm/source/mkvmuxer.hpp"
#include "ui/gfx/geometry/size.h"
namespace media {
class VideoFrame;
// 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 frame. WebM container has no Trailer.
// Clients will push encoded VPx video frames one by one via the
// OnEncodedVideo(). libwebm will eventually ping the WriteDataCB passed on
// contructor with the wrapped encoded data. All operations must happen in a
// single thread, where WebmMuxer is created and destroyed.
// [1] http://www.webmproject.org/docs/container/
// [2] http://www.matroska.org/technical/specs/index.html
// TODO(mcasas): Add support for Audio muxing.
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. The chunk is described as a byte
// array and a byte length.
using WriteDataCB = base::Callback<void(const base::StringPiece&)>;
explicit WebmMuxer(const WriteDataCB& write_data_callback);
~WebmMuxer() override;
// Adds a |video_frame| with |encoded_data.data()| to WebM Segment.
// TODO(mcasas): Revisit how |encoded_data| is passed once the whole recording
// chain is setup (http://crbug.com/262211).
void OnEncodedVideo(const scoped_refptr<VideoFrame>& video_frame,
const base::StringPiece& encoded_data,
base::TimeTicks timestamp,
bool is_key_frame);
private:
friend class WebmMuxerTest;
// Creates and adds a new video track. Called upon receiving the first
// frame of a given Track, adds |frame_size| and |frame_rate| to the Segment
// info, although individual frames passed to OnEncodedVideo() can have any
// frame size. Returns OnEncodedVideo() callback with a |track_number| bound
// in the callback.
void AddVideoTrack(const gfx::Size& frame_size, double frame_rate);
// 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;
// Used to DCHECK that we are called on the correct thread.
base::ThreadChecker thread_checker_;
// A caller-side identifier to interact with |segment_|, initialised upon
// first frame arrival by AddVideoTrack().
uint64_t track_index_;
// Origin of times for frame timestamps.
base::TimeTicks first_frame_timestamp_;
// 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_;
DISALLOW_COPY_AND_ASSIGN(WebmMuxer);
};
} // namespace media
#endif // MEDIA_FILTERS_LIBWEBM_MUXER_H_
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