media/formats/mp4/bitstream_converter.h

   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_FORMATS_MP4_BITSTREAM_CONVERTER_H_
   6 #define MEDIA_FORMATS_MP4_BITSTREAM_CONVERTER_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/memory/ref_counted.h"
  12
  13 namespace media {
  14
  15 struct SubsampleEntry;
  16
  17 namespace mp4 {
  18
  19 // BitstreamConverter provides a unified interface for performing some common
  20 // bitstream conversions (e.g. H.264 MP4 bitstream to Annex B, and elementary
  21 // AAC stream to ADTS).
  22 class BitstreamConverter
  23     : public base::RefCountedThreadSafe<BitstreamConverter> {
  24  public:
  25   // Converts a single frame/buffer |frame_buf| into the output format.
  26   // Returns true iff the conversion was successful.
  27   // |frame_buf| is an input/output parameter, it contains input frame data and
  28   // contains converted output data if conversion was successful.
  29   // |is_keyframe| indicates whether it's a key frame or not.
  30   // |subsamples| is an input/output parameter that contains CENC subsample
  31   // information. The conversion code should |subsamples| to determine if parts
  32   // of input frame are encrypted and should update |subsamples| if necessary,
  33   // to make sure it correctly describes the converted output frame. See
  34   // SubsampleEntry definition in media/base/decrypt_config.h for more info.
  35   virtual bool ConvertFrame(std::vector<uint8>* frame_buf,
  36                             bool is_keyframe,
  37                             std::vector<SubsampleEntry>* subsamples) const = 0;
  38  protected:
  39   friend class base::RefCountedThreadSafe<BitstreamConverter>;
  40   virtual ~BitstreamConverter();
  41 };
  42
  43 }  // namespace mp4
  44 }  // namespace media
  45
  46 #endif  // MEDIA_FORMATS_MP4_AVC_H_