media/capture: Adding WebmMuxer class and unittests

media/filters/webm_muxer.h

+// 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 <vector>
+
+#include "base/callback.h"
+#include "base/gtest_prod_util.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 MEDIA_EXPORT WebmMuxer : public mkvmuxer::IMkvWriter {
+ public:
+  typedef base::Callback<void(const char*, int, bool)> WriteDataCB;
+
+  explicit WebmMuxer(const WriteDataCB& write_data_callback);
+  ~WebmMuxer() override;
+
+  void OnEncodedVideo(int track_index,
+                      const std::string& encoded_data,
+                      const base::TimeTicks& timestamp,
+                      bool keyframe,
+                      const gfx::Size& frame_size,
+                      double frame_rate);
+
+ private:
+  friend class WebmMuxerTest;
+  FRIEND_TEST_ALL_PREFIXES(WebmMuxerTest, Write);
+  FRIEND_TEST_ALL_PREFIXES(WebmMuxerTest, OnEncodedVideo);
+
+  // Add a new video track when receiving the first frame.
+  bool AddVideoTrack(const gfx::Size& frame_size,
+                     double frame_rate,
+                     int track_index_starting_from_one);
+
+  // 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_;
+
+  // Class creation time.
+  const base::TimeTicks time_start_;
+
+  // Rolling counter of the position in bytes of the written goo.
+  int64_t position_;
+
+  // Local cache of track indexes to speed up adding a new track when seen for
+  // the first time.
+  std::vector<int> track_indexes_;
+
+  // Owned pointer to the MkvMuxer active element.
+  scoped_ptr<mkvmuxer::Segment> segment_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebmMuxer);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_FILTERS_LIBWEBM_MUXER_H_