Refactor AnnexB bitstream conversion for AVC/H.264

media/formats/mp4/avc.h

 // Copyright 2014 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_FORMATS_MP4_AVC_H_
 #define MEDIA_FORMATS_MP4_AVC_H_
 
 #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 {
 
 struct SubsampleEntry;
 
 namespace mp4 {
 
 struct AVCDecoderConfigurationRecord;
 
 class MEDIA_EXPORT AVC {
@@ skipping 28 matching lines @@
   static bool IsValidAnnexB(const uint8* buffer, size_t size,
                             const std::vector<SubsampleEntry>& subsamples);
 
   // Given a |buffer| and |subsamples| information and |pts| pointer into the
   // |buffer| finds the index of the subsample |ptr| is pointing into.
   static int FindSubsampleIndex(const std::vector<uint8>& buffer,
                                 const std::vector<SubsampleEntry>* subsamples,
                                 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
 
 #endif  // MEDIA_FORMATS_MP4_AVC_H_