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utils.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 "internal.h"
20 #include "libavutil/opt.h"
21 #include "libavformat/avformat.h"
22 
24 {
26  int ret = 0;
27 
28  *avctx = NULL;
29  if (!iformat && !format)
30  return AVERROR(EINVAL);
31  if (!(s = avformat_alloc_context()))
32  return AVERROR(ENOMEM);
33 
34  if (!iformat)
35  iformat = av_find_input_format(format);
36  if (!iformat || !iformat->priv_class || !AV_IS_INPUT_DEVICE(iformat->priv_class->category)) {
37  ret = AVERROR(EINVAL);
38  goto error;
39  }
40  s->iformat = iformat;
41  if (s->iformat->priv_data_size > 0) {
43  if (!s->priv_data) {
44  ret = AVERROR(ENOMEM);
45  goto error;
46  }
47  if (s->iformat->priv_class) {
48  *(const AVClass**)s->priv_data= s->iformat->priv_class;
50  }
51  } else
52  s->priv_data = NULL;
53 
54  *avctx = s;
55  return 0;
56  error:
58  return ret;
59 }
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:768
static const char * format[]
Definition: af_aiir.c:311
int ff_alloc_input_device_context(AVFormatContext **avctx, AVInputFormat *iformat, const char *format)
Definition: utils.c:23
void av_opt_set_defaults(void *s)
Set the values of all AVOption fields to their default values.
Definition: opt.c:1292
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:236
int priv_data_size
Size of private data so that it can be allocated in the wrapper.
Definition: avformat.h:698
Format I/O context.
Definition: avformat.h:1342
AVOptions.
#define AV_IS_INPUT_DEVICE(category)
Definition: log.h:50
AVFormatContext * avformat_alloc_context(void)
Allocate an AVFormatContext.
Definition: options.c:144
const AVClass * priv_class
AVClass for the private context.
Definition: avformat.h:672
#define AVERROR(e)
Definition: error.h:43
AVClassCategory category
Category used for visualization (like color) This is only set if the category is equal for all object...
Definition: log.h:130
AVInputFormat * av_find_input_format(const char *short_name)
Find AVInputFormat based on the short name of the input format.
Definition: format.c:118
static void error(const char *err)
static AVInputFormat * iformat
Definition: ffprobe.c:253
Describe the class of an AVClass context structure.
Definition: log.h:67
void avformat_free_context(AVFormatContext *s)
Free an AVFormatContext and all its streams.
Definition: utils.c:4384
Main libavformat public API header.
struct AVInputFormat * iformat
The input container format.
Definition: avformat.h:1354
void * priv_data
Format private data.
Definition: avformat.h:1370