FFmpeg
adts_parser.c
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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 #include "config.h"
20 
21 #include <stddef.h>
22 #include <stdint.h>
23 
24 #include "adts_header.h"
25 #include "adts_parser.h"
26 
28 {
29 #if CONFIG_ADTS_HEADER
30  GetBitContext gb;
32  int err = init_get_bits8(&gb, buf, AV_AAC_ADTS_HEADER_SIZE);
33  if (err < 0)
34  return err;
35  err = ff_adts_header_parse(&gb, &hdr);
36  if (err < 0)
37  return err;
38  *samples = hdr.samples;
39  *frames = hdr.num_aac_frames;
40  return 0;
41 #else
42  return AVERROR(ENOSYS);
43 #endif
44 }
if it could not because there are no more frames
int av_adts_header_parse(const uint8_t *buf, uint32_t *samples, uint8_t *frames)
Extract the number of samples and frames from AAC data.
Definition: adts_parser.c:27
uint8_t
#define AV_AAC_ADTS_HEADER_SIZE
Definition: adts_parser.h:25
uint8_t num_aac_frames
Definition: adts_header.h:36
uint32_t samples
Definition: adts_header.h:30
int ff_adts_header_parse(GetBitContext *gbc, AACADTSHeaderInfo *hdr)
Parse the ADTS frame header to the end of the variable header, which is the first 54 bits...
Definition: adts_header.c:30
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:677
void * buf
Definition: avisynth_c.h:766
Filter the word “frame” indicates either a video frame or a group of audio samples
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions