1 // Copyright 2012 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #ifndef MEDIA_FILTERS_FFMPEG_H264_TO_ANNEX_B_BITSTREAM_CONVERTER_H_
6 #define MEDIA_FILTERS_FFMPEG_H264_TO_ANNEX_B_BITSTREAM_CONVERTER_H_
8 #include "base/memory/raw_ptr.h"
9 #include "media/base/media_export.h"
10 #include "media/filters/ffmpeg_bitstream_converter.h"
11 #include "media/filters/h264_to_annex_b_bitstream_converter.h"
13 // Forward declarations for FFmpeg datatypes used.
14 struct AVCodecParameters;
19 // Bitstream converter that converts H.264 bitstream based FFmpeg packets into
20 // H.264 Annex B bytestream format.
21 class MEDIA_EXPORT FFmpegH264ToAnnexBBitstreamConverter
22 : public FFmpegBitstreamConverter {
24 // The |stream_codec_parameters| will be used during conversion and should be
25 // the AVCodecParameters for the stream sourcing these packets. A reference to
26 // |stream_codec_parameters| is retained, so it must outlive this class.
27 explicit FFmpegH264ToAnnexBBitstreamConverter(
28 AVCodecParameters* stream_codec_parameters);
30 FFmpegH264ToAnnexBBitstreamConverter(
31 const FFmpegH264ToAnnexBBitstreamConverter&) = delete;
32 FFmpegH264ToAnnexBBitstreamConverter& operator=(
33 const FFmpegH264ToAnnexBBitstreamConverter&) = delete;
35 ~FFmpegH264ToAnnexBBitstreamConverter() override;
37 // FFmpegBitstreamConverter implementation.
38 // Converts |packet| to H.264 Annex B bytestream format. This conversion is
39 // on single NAL unit basis which is contained within the |packet| with the
40 // exception of the first packet which is prepended with the AVC decoder
41 // configuration record information. For example:
43 // NAL unit #1 ==> bytestream buffer #1 (AVC configuraion + NAL unit #1)
44 // NAL unit #2 ==> bytestream buffer #2 (NAL unit #2)
46 // NAL unit #n ==> bytestream buffer #n (NAL unit #n)
48 // Returns true if conversion succeeded. In this case, the output will be
49 // stored into the |packet|. But user should be aware that this conversion can
50 // free and reallocate the |packet|, if it needs to do so to fit it in.
51 // FFmpeg allocation methods will be used for buffer allocation to ensure
52 // compatibility with FFmpeg's memory management.
54 // Returns false if conversion failed. In this case, the |packet| will not
56 bool ConvertPacket(AVPacket* packet) override;
59 // Actual converter class.
60 H264ToAnnexBBitstreamConverter converter_;
62 // Flag for indicating whether global parameter sets have been processed.
63 bool configuration_processed_;
65 // Variable to hold a pointer to memory where we can access the global
66 // data from the FFmpeg file format's global headers.
67 raw_ptr<AVCodecParameters, AcrossTasksDanglingUntriaged>
68 stream_codec_parameters_;
73 #endif // MEDIA_FILTERS_FFMPEG_H264_TO_ANNEX_B_BITSTREAM_CONVERTER_H_