mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2024-12-20 22:41:11 +00:00
12ded9cd85
Most users of ff_adts_header_parse() don't already have an opened GetBitContext for the header, so add a convenience function for them. Also use a forward declaration of GetBitContext in adts_header.h as this avoids (implicit) inclusion of get_bits.h in some of the users that now no longer use a GetBitContext of their own. Reviewed-by: James Almer <jamrial@gmail.com> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
84 lines
2.9 KiB
C
84 lines
2.9 KiB
C
/*
|
|
* Audio and Video frame extraction
|
|
* Copyright (c) 2003 Fabrice Bellard
|
|
* Copyright (c) 2003 Michael Niedermayer
|
|
* Copyright (c) 2009 Alex Converse
|
|
*
|
|
* 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 "adts_header.h"
|
|
#include "adts_parser.h"
|
|
#include "get_bits.h"
|
|
#include "mpeg4audio.h"
|
|
#include "libavutil/avassert.h"
|
|
|
|
int ff_adts_header_parse(GetBitContext *gbc, AACADTSHeaderInfo *hdr)
|
|
{
|
|
int size, rdb, ch, sr;
|
|
int aot, crc_abs;
|
|
|
|
memset(hdr, 0, sizeof(*hdr));
|
|
|
|
if (get_bits(gbc, 12) != 0xfff)
|
|
return AAC_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_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 < AV_AAC_ADTS_HEADER_SIZE)
|
|
return AAC_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;
|
|
hdr->frame_length = size;
|
|
|
|
return size;
|
|
}
|
|
|
|
int ff_adts_header_parse_buf(const uint8_t buf[AV_AAC_ADTS_HEADER_SIZE + AV_INPUT_BUFFER_PADDING_SIZE],
|
|
AACADTSHeaderInfo *hdr)
|
|
{
|
|
GetBitContext gb;
|
|
av_unused int ret = init_get_bits8(&gb, buf, AV_AAC_ADTS_HEADER_SIZE);
|
|
av_assert1(ret >= 0);
|
|
return ff_adts_header_parse(&gb, hdr);
|
|
}
|