src/media/filters/legacy_frame_processor.h

   1 // Copyright 2014 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_LEGACY_FRAME_PROCESSOR_H_
   6 #define MEDIA_FILTERS_LEGACY_FRAME_PROCESSOR_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/time/time.h"
  10 #include "media/base/media_export.h"
  11 #include "media/base/stream_parser.h"
  12 #include "media/filters/frame_processor_base.h"
  13
  14 namespace media {
  15
  16 // Helper class that implements Media Source Extension's coded frame processing
  17 // algorithm.
  18 class MEDIA_EXPORT LegacyFrameProcessor : public FrameProcessorBase {
  19  public:
  20   // Callback signature used to notify ChunkDemuxer of an end timestamp that may
  21   // cause the duration to be updated.
  22   typedef base::Callback<void(base::TimeDelta)> IncreaseDurationCB;
  23
  24   explicit LegacyFrameProcessor(const IncreaseDurationCB& increase_duration_cb);
  25   virtual ~LegacyFrameProcessor();
  26
  27   // FrameProcessorBase implementation
  28   virtual void SetSequenceMode(bool sequence_mode) OVERRIDE;
  29   virtual bool ProcessFrames(const StreamParser::BufferQueue& audio_buffers,
  30                              const StreamParser::BufferQueue& video_buffers,
  31                              const StreamParser::TextBufferQueueMap& text_map,
  32                              base::TimeDelta append_window_start,
  33                              base::TimeDelta append_window_end,
  34                              bool* new_media_segment,
  35                              base::TimeDelta* timestamp_offset) OVERRIDE;
  36
  37  private:
  38   // Helper function that adds |timestamp_offset| to each buffer in |buffers|.
  39   void AdjustBufferTimestamps(const StreamParser::BufferQueue& buffers,
  40                               base::TimeDelta timestamp_offset);
  41
  42   // Filters out buffers that are outside of the append window
  43   // [|append_window_start|, |append_window_end|). |track|'s
  44   // "needs random access point" is read and updated as this method filters
  45   // |buffers|. Buffers that are inside the append window are appended to the
  46   // end of |filtered_buffers|. |track| must be the track associated with all
  47   // items in |buffers|. |*new_media_segment| is set true if any of |buffers|
  48   // are filtered out.
  49   void FilterWithAppendWindow(base::TimeDelta append_window_start,
  50                               base::TimeDelta append_window_end,
  51                               const StreamParser::BufferQueue& buffers,
  52                               MseTrackBuffer* track,
  53                               bool* new_media_segment,
  54                               StreamParser::BufferQueue* filtered_buffers);
  55
  56   // Helper function that appends |buffers| to |stream| and calls
  57   // |increase_duration_cb_| to potentially update the duration.
  58   // Returns true if the append was successful. Returns false if
  59   // |stream| is NULL or something in |buffers| caused the append to fail.
  60   bool AppendAndUpdateDuration(ChunkDemuxerStream* stream,
  61                                const StreamParser::BufferQueue& buffers);
  62
  63   // Helper function for Legacy ProcessFrames() when new text buffers have been
  64   // parsed.
  65   // Applies |timestamp_offset| to all buffers in |buffers|, filters |buffers|
  66   // with append window, and stores those filtered buffers into |filtered_text|
  67   // based on |text_track_id|. If any of |buffers| are filtered out by append
  68   // window, then |*new_media_segment| is set true.
  69   // Updates |lowest_segment_timestamp| to be the earliest decode timestamp of
  70   // all buffers in |filtered_text|.
  71   // Returns true on a successful call. Returns false if an error occurred while
  72   // processing the buffers.
  73   bool FilterTextBuffers(StreamParser::TrackId text_track_id,
  74                          base::TimeDelta append_window_start,
  75                          base::TimeDelta append_window_end,
  76                          base::TimeDelta timestamp_offset,
  77                          const StreamParser::BufferQueue& buffers,
  78                          bool* new_media_segment,
  79                          base::TimeDelta* lowest_segment_timestamp,
  80                          StreamParser::TextBufferQueueMap* filtered_text);
  81
  82   IncreaseDurationCB increase_duration_cb_;
  83
  84   DISALLOW_COPY_AND_ASSIGN(LegacyFrameProcessor);
  85 };
  86
  87 }  // namespace media
  88
  89 #endif  // MEDIA_FILTERS_LEGACY_FRAME_PROCESSOR_H_