FFmpeg  4.4.5
v4l2enc.c
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1 /*
2  * Copyright (c) 2013 Clément Bœsch
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include "v4l2-common.h"
22 #include "avdevice.h"
23 
24 typedef struct {
25  AVClass *class;
26  int fd;
27 } V4L2Context;
28 
30 {
31  int res = 0, flags = O_RDWR;
32  struct v4l2_format fmt = {
33  .type = V4L2_BUF_TYPE_VIDEO_OUTPUT
34  };
35  V4L2Context *s = s1->priv_data;
36  AVCodecParameters *par;
37  uint32_t v4l2_pixfmt;
38 
39  if (s1->flags & AVFMT_FLAG_NONBLOCK)
40  flags |= O_NONBLOCK;
41 
42  s->fd = open(s1->url, flags);
43  if (s->fd < 0) {
44  res = AVERROR(errno);
45  av_log(s1, AV_LOG_ERROR, "Unable to open V4L2 device '%s'\n", s1->url);
46  return res;
47  }
48 
49  if (s1->nb_streams != 1 ||
50  s1->streams[0]->codecpar->codec_type != AVMEDIA_TYPE_VIDEO) {
52  "V4L2 output device supports only a single raw video stream\n");
53  return AVERROR(EINVAL);
54  }
55 
56  par = s1->streams[0]->codecpar;
57 
58  if(par->codec_id == AV_CODEC_ID_RAWVIDEO) {
59  v4l2_pixfmt = ff_fmt_ff2v4l(par->format, AV_CODEC_ID_RAWVIDEO);
60  } else {
61  v4l2_pixfmt = ff_fmt_ff2v4l(AV_PIX_FMT_NONE, par->codec_id);
62  }
63 
64  if (!v4l2_pixfmt) { // XXX: try to force them one by one?
65  av_log(s1, AV_LOG_ERROR, "Unknown V4L2 pixel format equivalent for %s\n",
67  return AVERROR(EINVAL);
68  }
69 
70  if (ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
71  res = AVERROR(errno);
72  av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n", av_err2str(res));
73  return res;
74  }
75 
76  fmt.fmt.pix.width = par->width;
77  fmt.fmt.pix.height = par->height;
78  fmt.fmt.pix.pixelformat = v4l2_pixfmt;
79  fmt.fmt.pix.sizeimage = av_image_get_buffer_size(par->format, par->width, par->height, 1);
80 
81  if (ioctl(s->fd, VIDIOC_S_FMT, &fmt) < 0) {
82  res = AVERROR(errno);
83  av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_S_FMT): %s\n", av_err2str(res));
84  return res;
85  }
86 
87  return res;
88 }
89 
91 {
92  const V4L2Context *s = s1->priv_data;
93  if (write(s->fd, pkt->data, pkt->size) == -1)
94  return AVERROR(errno);
95  return 0;
96 }
97 
99 {
100  const V4L2Context *s = s1->priv_data;
101  close(s->fd);
102  return 0;
103 }
104 
105 static const AVClass v4l2_class = {
106  .class_name = "V4L2 outdev",
107  .item_name = av_default_item_name,
108  .version = LIBAVUTIL_VERSION_INT,
110 };
111 
113  .name = "video4linux2,v4l2",
114  .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 output device"),
115  .priv_data_size = sizeof(V4L2Context),
116  .audio_codec = AV_CODEC_ID_NONE,
117  .video_codec = AV_CODEC_ID_RAWVIDEO,
121  .flags = AVFMT_NOFILE,
122  .priv_class = &v4l2_class,
123 };
#define av_cold
Definition: attributes.h:88
Main libavdevice API header.
#define AVFMT_FLAG_NONBLOCK
Do not block when reading packets from input.
Definition: avformat.h:1366
#define AVFMT_NOFILE
Demuxer will use avio_open, no opened file should be provided by the caller.
Definition: avformat.h:458
#define flags(name, subs,...)
Definition: cbs_av1.c:572
#define s(width, name)
Definition: cbs_vp9.c:257
@ AV_CODEC_ID_RAWVIDEO
Definition: codec_id.h:62
@ AV_CODEC_ID_NONE
Definition: codec_id.h:47
#define av_err2str(errnum)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: error.h:119
#define AVERROR(e)
Definition: error.h:43
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
int av_image_get_buffer_size(enum AVPixelFormat pix_fmt, int width, int height, int align)
Return the size in bytes of the amount of data required to store an image with the given parameters.
Definition: imgutils.c:466
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
@ AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT
Definition: log.h:41
const char * av_get_pix_fmt_name(enum AVPixelFormat pix_fmt)
Return the short name for a pixel format, NULL in case pix_fmt is unknown.
Definition: pixdesc.c:2489
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:65
#define s1
Definition: regdef.h:38
Describe the class of an AVClass context structure.
Definition: log.h:67
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
This struct describes the properties of an encoded stream.
Definition: codec_par.h:52
int width
Video only.
Definition: codec_par.h:126
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
Format I/O context.
Definition: avformat.h:1232
const char * name
Definition: avformat.h:491
This structure stores compressed data.
Definition: packet.h:346
int size
Definition: packet.h:370
uint8_t * data
Definition: packet.h:369
int fd
Definition: v4l2enc.c:26
#define av_log(a,...)
AVPacket * pkt
Definition: movenc.c:59
uint32_t ff_fmt_ff2v4l(enum AVPixelFormat pix_fmt, enum AVCodecID codec_id)
Definition: v4l2-common.c:73
static av_cold int write_header(AVFormatContext *s1)
Definition: v4l2enc.c:29
static int write_trailer(AVFormatContext *s1)
Definition: v4l2enc.c:98
static const AVClass v4l2_class
Definition: v4l2enc.c:105
AVOutputFormat ff_v4l2_muxer
Definition: v4l2enc.c:112
static int write_packet(AVFormatContext *s1, AVPacket *pkt)
Definition: v4l2enc.c:90