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| 1 // Copyright 2015 The Chromium Authors. All rights reserved. |
| 2 // Use of this source code is governed by a BSD-style license that can be |
| 3 // found in the LICENSE file. |
| 4 |
| 5 #ifndef MEDIA_FILTERS_LIBWEBM_MUXER_H_ |
| 6 #define MEDIA_FILTERS_LIBWEBM_MUXER_H_ |
| 7 |
| 8 #include <set> |
| 9 |
| 10 #include "base/callback.h" |
| 11 #include "base/gtest_prod_util.h" |
| 12 #include "base/numerics/safe_math.h" |
| 13 #include "base/strings/string_piece.h" |
| 14 #include "base/threading/thread_checker.h" |
| 15 #include "base/time/time.h" |
| 16 #include "media/base/media_export.h" |
| 17 #include "third_party/libwebm/source/mkvmuxer.hpp" |
| 18 #include "ui/gfx/geometry/size.h" |
| 19 |
| 20 namespace media { |
| 21 |
| 22 // Adapter class to manage a WebM container [1], a simplified version of a |
| 23 // Matroska container [2], composed of an EBML header, and a single Segment |
| 24 // including at least a Track Section and a number of SimpleBlocks each |
| 25 // containing a single encoded video frame. WebM container has no Trailer. |
| 26 // Clients will push encoded VPx video frames one by one via OnEncodedVideo() |
| 27 // with indication of the Track they belong to, and libwebm will eventually ping |
| 28 // the WriteDataCB passed on contructor with the wrapped encoded data. All |
| 29 // operations must happen in a single thread, where WebmMuxer is created and |
| 30 // destroyed. |
| 31 // [1] http://www.webmproject.org/docs/container/ |
| 32 // [2] http://www.matroska.org/technical/specs/index.html |
| 33 // TODO(mcasas): Add support for Audio muxing. |
| 34 class MEDIA_EXPORT WebmMuxer : public NON_EXPORTED_BASE(mkvmuxer::IMkvWriter) { |
| 35 public: |
| 36 // Callback to be called when WebmMuxer is ready to write a chunk of data, |
| 37 // either any file header or a SingleBlock. The chunk is described as a byte |
| 38 // array and a byte length. |
| 39 using WriteDataCB = base::Callback<void(const base::StringPiece&)>; |
| 40 |
| 41 explicit WebmMuxer(const WriteDataCB& write_data_callback); |
| 42 ~WebmMuxer() override; |
| 43 |
| 44 // Creates and adds a new video track. Called before receiving the first |
| 45 // frame of a given Track, adds |frame_size| and |frame_rate| to the Segment |
| 46 // info, although individual frames passed to OnEncodedVideo() can have any |
| 47 // frame size. Returns the track_index to be used for OnEncodedVideo(). |
| 48 uint64_t AddVideoTrack(const gfx::Size& frame_size, double frame_rate); |
| 49 |
| 50 // Adds a frame with |encoded_data.data()| to WebM Segment. |track_number| is |
| 51 // a caller-side identifier and must have been provided by AddVideoTrack(). |
| 52 // TODO(mcasas): Revisit how |encoded_data| is passed once the whole recording |
| 53 // chain is setup (http://crbug.com/262211). |
| 54 void OnEncodedVideo(uint64_t track_number, |
| 55 const base::StringPiece& encoded_data, |
| 56 base::TimeDelta timestamp, |
| 57 bool keyframe); |
| 58 |
| 59 private: |
| 60 friend class WebmMuxerTest; |
| 61 |
| 62 // IMkvWriter interface. |
| 63 mkvmuxer::int32 Write(const void* buf, mkvmuxer::uint32 len) override; |
| 64 mkvmuxer::int64 Position() const override; |
| 65 mkvmuxer::int32 Position(mkvmuxer::int64 position) override; |
| 66 bool Seekable() const override; |
| 67 void ElementStartNotify(mkvmuxer::uint64 element_id, |
| 68 mkvmuxer::int64 position) override; |
| 69 |
| 70 // Used to DCHECK that we are called on the correct thread. |
| 71 base::ThreadChecker thread_checker_; |
| 72 |
| 73 // Callback to dump written data as being called by libwebm. |
| 74 const WriteDataCB write_data_callback_; |
| 75 |
| 76 // Rolling counter of the position in bytes of the written goo. |
| 77 base::CheckedNumeric<mkvmuxer::int64> position_; |
| 78 |
| 79 // The MkvMuxer active element. |
| 80 mkvmuxer::Segment segment_; |
| 81 |
| 82 DISALLOW_COPY_AND_ASSIGN(WebmMuxer); |
| 83 }; |
| 84 |
| 85 } // namespace media |
| 86 |
| 87 #endif // MEDIA_FILTERS_LIBWEBM_MUXER_H_ |
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