mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-02 03:06:28 +02:00
92dc9c9d68
Required by MP4's AC3SpecificBox and MPEG-TS AC-3 audio_descriptor, of which the former is implemented in our MP4 writer. Signed-off-by: Jan Ekström <jan.ekstrom@24i.com>
83 lines
2.6 KiB
C
83 lines
2.6 KiB
C
/*
|
|
* AC-3 parser internal code
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*
|
|
* FFmpeg is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser General Public
|
|
* License along with FFmpeg; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*/
|
|
|
|
#ifndef AVCODEC_AC3_PARSER_INTERNAL_H
|
|
#define AVCODEC_AC3_PARSER_INTERNAL_H
|
|
|
|
#include <stddef.h>
|
|
#include <stdint.h>
|
|
|
|
#include "ac3defs.h"
|
|
#include "get_bits.h"
|
|
|
|
/**
|
|
* @struct AC3HeaderInfo
|
|
* Coded AC-3 header values up to the lfeon element, plus derived values.
|
|
*/
|
|
typedef struct AC3HeaderInfo {
|
|
/** @name Coded elements
|
|
* @{
|
|
*/
|
|
uint16_t sync_word;
|
|
uint16_t crc1;
|
|
uint8_t sr_code;
|
|
uint8_t bitstream_id;
|
|
uint8_t bitstream_mode;
|
|
uint8_t channel_mode;
|
|
uint8_t lfe_on;
|
|
uint8_t frame_type;
|
|
int substreamid; ///< substream identification
|
|
int center_mix_level; ///< Center mix level index
|
|
int surround_mix_level; ///< Surround mix level index
|
|
uint16_t channel_map;
|
|
int num_blocks; ///< number of audio blocks
|
|
int dolby_surround_mode;
|
|
/** @} */
|
|
|
|
/** @name Derived values
|
|
* @{
|
|
*/
|
|
uint8_t sr_shift;
|
|
uint16_t sample_rate;
|
|
uint32_t bit_rate;
|
|
uint8_t channels;
|
|
uint16_t frame_size;
|
|
uint64_t channel_layout;
|
|
int8_t ac3_bit_rate_code;
|
|
/** @} */
|
|
} AC3HeaderInfo;
|
|
|
|
/**
|
|
* Parse AC-3 frame header.
|
|
* Parse the header up to the lfeon element, which is the first 52 or 54 bits
|
|
* depending on the audio coding mode.
|
|
* @param[in] gbc BitContext containing the first 54 bits of the frame.
|
|
* @param[out] hdr Pointer to struct where header info is written.
|
|
* @return Returns 0 on success, -1 if there is a sync word mismatch,
|
|
* -2 if the bsid (version) element is invalid, -3 if the fscod (sample rate)
|
|
* element is invalid, or -4 if the frmsizecod (bit rate) element is invalid.
|
|
*/
|
|
int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr);
|
|
|
|
int avpriv_ac3_parse_header(AC3HeaderInfo **hdr, const uint8_t *buf,
|
|
size_t size);
|
|
|
|
#endif /* AVCODEC_AC3_PARSER_INTERNAL_H */
|