Index: media/capture/webm_muxer.h |
diff --git a/media/capture/webm_muxer.h b/media/capture/webm_muxer.h |
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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 { |
+ |
+// 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 OnEncodedVideo() |
+// with indication of the Track they belong to, and 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; |
+ |
+ // Creates and adds a new video track. Called before 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 the track_index to be used for OnEncodedVideo(). |
+ uint64_t AddVideoTrack(const gfx::Size& frame_size, double frame_rate); |
+ |
+ // Adds a frame with |encoded_data.data()| to WebM Segment. |track_number| is |
+ // a caller-side identifier and must have been provided by AddVideoTrack(). |
+ // TODO(mcasas): Revisit how |encoded_data| is passed once the whole recording |
+ // chain is setup (http://crbug.com/262211). |
+ void OnEncodedVideo(uint64_t track_number, |
+ const base::StringPiece& encoded_data, |
+ base::TimeDelta timestamp, |
+ bool keyframe); |
+ |
+ private: |
+ friend class WebmMuxerTest; |
+ |
+ // 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_; |
+ |
+ // 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_ |