Refactor AnnexB bitstream conversion for AVC/H.264

media/formats/mp4/avc.h

Index: media/formats/mp4/avc.h
diff --git a/media/formats/mp4/avc.h b/media/formats/mp4/avc.h
index add88bbcfa116594206fcee91f55ec9b14986a30..a774ddd1b7320aaae000bfa885a2b56dadb23420 100644
--- a/media/formats/mp4/avc.h
+++ b/media/formats/mp4/avc.h
@@ -8,7 +8,9 @@
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
 #include "media/base/media_export.h"
+#include "media/formats/mp4/bitstream_converter.h"
 
 namespace media {
 
@@ -57,6 +59,24 @@ class MEDIA_EXPORT AVC {
                                 const uint8* ptr);
 };
 
+// AVCBitstreamConverter converts AVC/H.264 bitstream from MP4 container format
+// with embedded NALU lengths into AnnexB bitstream format (described in ISO/IEC
+// 14496-10) with 4-byte start codes. It also knows how to handle CENC-encrypted
+// streams and adjusts subsample data for those streams while converting.
+class AVCBitstreamConverter : public BitstreamConverter {
+ public:
+  explicit AVCBitstreamConverter(
+      scoped_ptr<AVCDecoderConfigurationRecord> avc_config);
+
+  // BitstreamConverter interface
+  bool ConvertFrame(std::vector<uint8>* frame_buf,
+                    bool is_keyframe,
+                    std::vector<SubsampleEntry>* subsamples) const override;
+ private:
+  ~AVCBitstreamConverter() override;
+  scoped_ptr<AVCDecoderConfigurationRecord> avc_config_;
+};
+
 }  // namespace mp4
 }  // namespace media