shaka-packager/media/formats/mp2t/adts_header.h

75 lines
2.5 KiB
C++

// Copyright 2014 Google Inc. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd
#ifndef MEDIA_FORMATS_MP2T_ADTS_HEADER_H_
#define MEDIA_FORMATS_MP2T_ADTS_HEADER_H_
#include "base/basictypes.h"
#include <vector>
namespace edash_packager {
namespace media {
namespace mp2t {
/// Class which parses ADTS headers and synthesizes AudioSpecificConfig
/// and audio mime type from ADTS header contents.
class AdtsHeader {
public:
AdtsHeader();
~AdtsHeader() {}
/// Get the size of the ADTS frame from a partial or complete frame.
/// @param data is a pointer to the beginning of the ADTS frame.
/// @param num_bytes is the number of data bytes at @a data.
/// @return Size of the ADTS frame (header + payload) if successful, or
/// zero otherwise.
static size_t GetAdtsFrameSize(const uint8* data, size_t num_bytes);
/// Get the size of the ADTS header from a partial or complete frame.
/// @param data is a pointer to the beginning of the ADTS frame.
/// @param num_bytes is the number of data bytes at @a data.
/// @return Size of the ADTS header if successful, or zero otherwise.
static size_t GetAdtsHeaderSize(const uint8* data, size_t num_bytes);
/// Parse an ADTS header, extracting the fields within.
/// @param adts_frame is an input parameter pointing to the ADTS header
/// of an ADTS-framed audio sample.
/// @param adts_frame_size is the size, in bytes of the input ADTS frame.
/// @return true if successful, false otherwise.
bool Parse(const uint8* adts_frame, size_t adts_frame_size);
/// Synthesize an AudioSpecificConfig record from the fields within the ADTS
/// header.
/// @param [out] buffer is a pointer to a vector to contain the
/// AudioSpecificConfig.
/// @return true if successful, false otherwise.
bool GetAudioSpecificConfig(std::vector<uint8>* buffer) const;
/// @return The audio profile for this ADTS frame.
uint8 GetObjectType() const;
/// @return The sampling frequency for this ADTS frame.
uint32 GetSamplingFrequency() const;
/// @return Number of channels for this AAC config.
uint8 GetNumChannels() const;
private:
bool valid_config_;
uint8 profile_;
uint8 sampling_frequency_index_;
uint8 channel_configuration_;
DISALLOW_COPY_AND_ASSIGN(AdtsHeader);
};
} // namespace mp2t
} // namespace media
} // namespace edash_packager
#endif // MEDIA_FORMATS_MP2T_ADTS_HEADER_H_