media/filters/ffmpeg_aac_bitstream_converter.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_FFMPEG_AAC_BITSTREAM_CONVERTER_H_
   6 #define MEDIA_FILTERS_FFMPEG_AAC_BITSTREAM_CONVERTER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "media/base/media_export.h"
  10 #include "media/filters/ffmpeg_bitstream_converter.h"
  11
  12 // Forward declarations for FFmpeg datatypes used.
  13 struct AVCodecContext;
  14 struct AVPacket;
  15
  16 namespace media {
  17
  18 // Bitstream converter that adds ADTS headers to AAC frames.
  19 class MEDIA_EXPORT FFmpegAACBitstreamConverter
  20     : public FFmpegBitstreamConverter {
  21  public:
  22   enum { kAdtsHeaderSize = 7 };
  23
  24   // The |stream_codec_context| will be used during conversion and should be the
  25   // AVCodecContext for the stream sourcing these packets. A reference to
  26   // |stream_codec_context| is retained, so it must outlive this class.
  27   explicit FFmpegAACBitstreamConverter(AVCodecContext* stream_codec_context);
  28   ~FFmpegAACBitstreamConverter() override;
  29
  30   // FFmpegBitstreamConverter implementation.
  31   // Uses FFmpeg allocation methods for buffer allocation to ensure
  32   // compatibility with FFmpeg's memory management.
  33   bool ConvertPacket(AVPacket* packet) override;
  34
  35  private:
  36   // Variable to hold a pointer to memory where we can access the global
  37   // data from the FFmpeg file format's global headers.
  38   AVCodecContext* stream_codec_context_;
  39
  40   bool header_generated_;
  41   uint8_t hdr_[kAdtsHeaderSize];
  42   int codec_;
  43   int audio_profile_;
  44   int sample_rate_index_;
  45   int channel_configuration_;
  46   int frame_length_;
  47
  48   DISALLOW_COPY_AND_ASSIGN(FFmpegAACBitstreamConverter);
  49 };
  50
  51 }  // namespace media
  52
  53 #endif  // MEDIA_FILTERS_FFMPEG_AAC_BITSTREAM_CONVERTER_H_