Reorganize bitstream converter classes.

media/filters/ffmpeg_h264_to_annex_b_bitstream_converter.h

Index: media/filters/ffmpeg_h264_to_annex_b_bitstream_converter.h
diff --git a/media/filters/ffmpeg_h264_to_annex_b_bitstream_converter.h b/media/filters/ffmpeg_h264_to_annex_b_bitstream_converter.h
new file mode 100644
index 0000000000000000000000000000000000000000..5ec3ab3f74a2e565a187ecc50b3e79298b440cf5
--- /dev/null
+++ b/media/filters/ffmpeg_h264_to_annex_b_bitstream_converter.h
@@ -0,0 +1,64 @@
+// Copyright (c) 2012 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_FILTERS_FFMPEG_H264_TO_ANNEX_B_BITSTREAM_CONVERTER_H_
+#define MEDIA_FILTERS_FFMPEG_H264_TO_ANNEX_B_BITSTREAM_CONVERTER_H_
+
+#include "base/basictypes.h"
+#include "media/filters/h264_to_annex_b_bitstream_converter.h"
+
+// Forward declarations for FFmpeg datatypes used.
+struct AVCodecContext;
+struct AVPacket;
+
+namespace media {
+
+// Bitstream converter that converts H.264 bitstream based FFmpeg packets into
+// H.264 Annex B bytestream format.
+class MEDIA_EXPORT FFmpegH264ToAnnexBBitstreamConverter {
+ public:
+  // The |stream_context| will be used during conversion and should be the
+  // AVCodecContext for the stream sourcing these packets. A reference to
+  // |stream_context| is retained, so it must outlive this class.
+  explicit FFmpegH264ToAnnexBBitstreamConverter(AVCodecContext* stream_context);
+  ~FFmpegH264ToAnnexBBitstreamConverter();
+
+  // Converts |packet| to H.264 Annex B bytestream format. This conversion is
+  // on single NAL unit basis which is contained within the |packet| with the
+  // exception of the first packet which is prepended with the AVC decoder
+  // configuration record information. For example:
+  //
+  //    NAL unit #1 ==> bytestream buffer #1 (AVC configuraion + NAL unit #1)
+  //    NAL unit #2 ==> bytestream buffer #2 (NAL unit #2)
+  //    ...
+  //    NAL unit #n ==> bytestream buffer #n (NAL unit #n)
+  //
+  // Returns true if conversion succeeded. In this case, the output will be
+  // stored into the |packet|. But user should be aware that this conversion can
+  // free and reallocate the |packet|, if it needs to do so to fit it in.
+  // FFmpeg allocation methods will be used for buffer allocation to ensure
+  // compatibility with FFmpeg's memory management.
+  //
+  // Returns false if conversion failed. In this case, the |packet| will not
+  // be changed.
+  bool ConvertPacket(AVPacket* packet);
+
+ private:
+  // Actual converter class.
+  H264ToAnnexBBitstreamConverter converter_;
+
+  // Flag for indicating whether global parameter sets have been processed.
+  bool configuration_processed_;
+
+  // Variable to hold a pointer to memory where we can access the global
+  // data from the FFmpeg file format's global headers.
+  AVCodecContext* stream_context_;
+
+  DISALLOW_COPY_AND_ASSIGN(FFmpegH264ToAnnexBBitstreamConverter);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_FILTERS_FFMPEG_H264_TO_ANNEX_B_BITSTREAM_CONVERTER_H_
+