mirror of
https://gitee.com/openharmony/third_party_ffmpeg
synced 2024-11-24 19:59:46 +00:00
113 lines
3.5 KiB
C
113 lines
3.5 KiB
C
/*
|
|
* Audio and Video frame extraction
|
|
* Copyright (c) 2003 Fabrice Bellard
|
|
* Copyright (c) 2003 Michael Niedermayer
|
|
*
|
|
* 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
|
|
*/
|
|
|
|
#include "parser.h"
|
|
#include "aac_ac3_parser.h"
|
|
#include "aac_parser.h"
|
|
#include "get_bits.h"
|
|
#include "mpeg4audio.h"
|
|
|
|
int ff_aac_parse_header(GetBitContext *gbc, AACADTSHeaderInfo *hdr)
|
|
{
|
|
int size, rdb, ch, sr;
|
|
int aot, crc_abs;
|
|
|
|
if(get_bits(gbc, 12) != 0xfff)
|
|
return AAC_AC3_PARSE_ERROR_SYNC;
|
|
|
|
skip_bits1(gbc); /* id */
|
|
skip_bits(gbc, 2); /* layer */
|
|
crc_abs = get_bits1(gbc); /* protection_absent */
|
|
aot = get_bits(gbc, 2); /* profile_objecttype */
|
|
sr = get_bits(gbc, 4); /* sample_frequency_index */
|
|
if(!ff_mpeg4audio_sample_rates[sr])
|
|
return AAC_AC3_PARSE_ERROR_SAMPLE_RATE;
|
|
skip_bits1(gbc); /* private_bit */
|
|
ch = get_bits(gbc, 3); /* channel_configuration */
|
|
|
|
skip_bits1(gbc); /* original/copy */
|
|
skip_bits1(gbc); /* home */
|
|
|
|
/* adts_variable_header */
|
|
skip_bits1(gbc); /* copyright_identification_bit */
|
|
skip_bits1(gbc); /* copyright_identification_start */
|
|
size = get_bits(gbc, 13); /* aac_frame_length */
|
|
if(size < AAC_ADTS_HEADER_SIZE)
|
|
return AAC_AC3_PARSE_ERROR_FRAME_SIZE;
|
|
|
|
skip_bits(gbc, 11); /* adts_buffer_fullness */
|
|
rdb = get_bits(gbc, 2); /* number_of_raw_data_blocks_in_frame */
|
|
|
|
hdr->object_type = aot + 1;
|
|
hdr->chan_config = ch;
|
|
hdr->crc_absent = crc_abs;
|
|
hdr->num_aac_frames = rdb + 1;
|
|
hdr->sampling_index = sr;
|
|
hdr->sample_rate = ff_mpeg4audio_sample_rates[sr];
|
|
hdr->samples = (rdb + 1) * 1024;
|
|
hdr->bit_rate = size * 8 * hdr->sample_rate / hdr->samples;
|
|
|
|
return size;
|
|
}
|
|
|
|
static int aac_sync(uint64_t state, AACAC3ParseContext *hdr_info,
|
|
int *need_next_header, int *new_frame_start)
|
|
{
|
|
GetBitContext bits;
|
|
AACADTSHeaderInfo hdr;
|
|
int size;
|
|
union {
|
|
uint64_t u64;
|
|
uint8_t u8[8];
|
|
} tmp;
|
|
|
|
tmp.u64 = be2me_64(state);
|
|
init_get_bits(&bits, tmp.u8+8-AAC_ADTS_HEADER_SIZE, AAC_ADTS_HEADER_SIZE * 8);
|
|
|
|
if ((size = ff_aac_parse_header(&bits, &hdr)) < 0)
|
|
return 0;
|
|
*need_next_header = 0;
|
|
*new_frame_start = 1;
|
|
hdr_info->sample_rate = hdr.sample_rate;
|
|
hdr_info->channels = ff_mpeg4audio_channels[hdr.chan_config];
|
|
hdr_info->samples = hdr.samples;
|
|
hdr_info->bit_rate = hdr.bit_rate;
|
|
return size;
|
|
}
|
|
|
|
static av_cold int aac_parse_init(AVCodecParserContext *s1)
|
|
{
|
|
AACAC3ParseContext *s = s1->priv_data;
|
|
s->header_size = AAC_ADTS_HEADER_SIZE;
|
|
s->sync = aac_sync;
|
|
return 0;
|
|
}
|
|
|
|
|
|
AVCodecParser aac_parser = {
|
|
{ CODEC_ID_AAC },
|
|
sizeof(AACAC3ParseContext),
|
|
aac_parse_init,
|
|
ff_aac_ac3_parse,
|
|
ff_parse_close,
|
|
};
|