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// 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_MPEG_MPEG_AUDIO_STREAM_PARSER_BASE_H_
#define MEDIA_FORMATS_MPEG_MPEG_AUDIO_STREAM_PARSER_BASE_H_
#include <stdint.h>
#include <memory>
#include <set>
#include <vector>
#include "base/callback.h"
#include "base/macros.h"
#include "media/base/audio_decoder_config.h"
#include "media/base/audio_timestamp_helper.h"
#include "media/base/bit_reader.h"
#include "media/base/byte_queue.h"
#include "media/base/media_export.h"
#include "media/base/stream_parser.h"
namespace media {
class MEDIA_EXPORT MPEGAudioStreamParserBase : public StreamParser {
public:
// |start_code_mask| is used to find the start of each frame header. Also
// referred to as the sync code in the MP3 and ADTS header specifications.
// |codec_delay| is the number of samples the decoder will output before the
// first real frame.
MPEGAudioStreamParserBase(uint32_t start_code_mask,
AudioCodec audio_codec,
int codec_delay);
~MPEGAudioStreamParserBase() override;
// StreamParser implementation.
void Init(InitCB init_cb,
const NewConfigCB& config_cb,
const NewBuffersCB& new_buffers_cb,
bool ignore_text_tracks,
const EncryptedMediaInitDataCB& encrypted_media_init_data_cb,
const NewMediaSegmentCB& new_segment_cb,
const EndMediaSegmentCB& end_of_segment_cb,
MediaLog* media_log) override;
void Flush() override;
bool GetGenerateTimestampsFlag() const override;
bool Parse(const uint8_t* buf, int size) override;
protected:
// Subclasses implement this method to parse format specific frame headers.
// |data| & |size| describe the data available for parsing.
//
// Implementations are expected to consume an entire frame header. It should
// only return a value greater than 0 when |data| has enough bytes to
// successfully parse & consume the entire frame header.
//
// |frame_size| - Required parameter that is set to the size of the frame, in
// bytes, including the frame header if the function returns a value > 0.
// |sample_rate| - Optional parameter that is set to the sample rate
// of the frame if this function returns a value > 0.
// |channel_layout| - Optional parameter that is set to the channel_layout
// of the frame if this function returns a value > 0.
// |sample_count| - Optional parameter that is set to the number of samples
// in the frame if this function returns a value > 0.
// |metadata_frame| - Optional parameter that is set to true if the frame has
// valid values for the above parameters, but no usable encoded data; only set
// to true if this function returns a value > 0.
//
// |sample_rate|, |channel_layout|, |sample_count|, |metadata_frame| may be
// NULL if the caller is not interested in receiving these values from the
// frame header.
//
// If |metadata_frame| is true, the MPEGAudioStreamParserBase will discard the
// frame after consuming the metadata values above.
//
// Returns:
// > 0 : The number of bytes parsed.
// 0 : If more data is needed to parse the entire frame header.
// < 0 : An error was encountered during parsing.
virtual int ParseFrameHeader(const uint8_t* data,
int size,
int* frame_size,
int* sample_rate,
ChannelLayout* channel_layout,
int* sample_count,
bool* metadata_frame,
std::vector<uint8_t>* extra_data) const = 0;
MediaLog* media_log() const { return media_log_; }
private:
enum State {
UNINITIALIZED,
INITIALIZED,
PARSE_ERROR
};
void ChangeState(State state);
// Parsing functions for various byte stream elements. |data| & |size|
// describe the data available for parsing.
//
// Returns:
// > 0 : The number of bytes parsed.
// 0 : If more data is needed to parse the entire element.
// < 0 : An error was encountered during parsing.
int ParseFrame(const uint8_t* data, int size, BufferQueue* buffers);
int ParseIcecastHeader(const uint8_t* data, int size);
int ParseID3v1(const uint8_t* data, int size);
int ParseID3v2(const uint8_t* data, int size);
// Parses an ID3v2 "sync safe" integer.
// |reader| - A BitReader to read from.
// |value| - Set to the integer value read, if true is returned.
//
// Returns true if the integer was successfully parsed and |value|
// was set.
// Returns false if an error was encountered. The state of |value| is
// undefined when false is returned.
bool ParseSyncSafeInt(BitReader* reader, int32_t* value);
// Scans |data| for the next valid start code.
// Returns:
// > 0 : The number of bytes that should be skipped to reach the
// next start code..
// 0 : If a valid start code was not found and more data is needed.
// < 0 : An error was encountered during parsing.
int FindNextValidStartCode(const uint8_t* data, int size) const;
// Sends the buffers in |buffers| to |new_buffers_cb_| and then clears
// |buffers|.
// If |end_of_segment| is set to true, then |end_of_segment_cb_| is called
// after |new_buffers_cb_| to signal that these buffers represent the end of a
// media segment.
// Returns true if the buffers are sent successfully.
bool SendBuffers(BufferQueue* buffers, bool end_of_segment);
State state_;
InitCB init_cb_;
NewConfigCB config_cb_;
NewBuffersCB new_buffers_cb_;
NewMediaSegmentCB new_segment_cb_;
EndMediaSegmentCB end_of_segment_cb_;
MediaLog* media_log_;
ByteQueue queue_;
AudioDecoderConfig config_;
std::unique_ptr<AudioTimestampHelper> timestamp_helper_;
bool in_media_segment_;
const uint32_t start_code_mask_;
const AudioCodec audio_codec_;
const int codec_delay_;
DISALLOW_COPY_AND_ASSIGN(MPEGAudioStreamParserBase);
};
} // namespace media
#endif // MEDIA_FORMATS_MPEG_MPEG_AUDIO_STREAM_PARSER_BASE_H_
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