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 "libavutil/imgutils.h"
22 #include "libavutil/pixdesc.h"
23 #include "libavformat/avformat.h"
24 #include "v4l2-common.h"
25
26 typedef struct {
27 AVClass *class;
28 int fd;
29 } V4L2Context;
30
write_header(AVFormatContext * s1)31 static av_cold int write_header(AVFormatContext *s1)
32 {
33 int res = 0, flags = O_RDWR;
34 struct v4l2_format fmt = {
35 .type = V4L2_BUF_TYPE_VIDEO_OUTPUT
36 };
37 V4L2Context *s = s1->priv_data;
38 AVCodecParameters *par;
39 uint32_t v4l2_pixfmt;
40
41 if (s1->flags & AVFMT_FLAG_NONBLOCK)
42 flags |= O_NONBLOCK;
43
44 s->fd = open(s1->url, flags);
45 if (s->fd < 0) {
46 res = AVERROR(errno);
47 av_log(s1, AV_LOG_ERROR, "Unable to open V4L2 device '%s'\n", s1->url);
48 return res;
49 }
50
51 if (s1->nb_streams != 1 ||
52 s1->streams[0]->codecpar->codec_type != AVMEDIA_TYPE_VIDEO) {
53 av_log(s1, AV_LOG_ERROR,
54 "V4L2 output device supports only a single raw video stream\n");
55 return AVERROR(EINVAL);
56 }
57
58 par = s1->streams[0]->codecpar;
59
60 if(par->codec_id == AV_CODEC_ID_RAWVIDEO) {
61 v4l2_pixfmt = ff_fmt_ff2v4l(par->format, AV_CODEC_ID_RAWVIDEO);
62 } else {
63 v4l2_pixfmt = ff_fmt_ff2v4l(AV_PIX_FMT_NONE, par->codec_id);
64 }
65
66 if (!v4l2_pixfmt) { // XXX: try to force them one by one?
67 av_log(s1, AV_LOG_ERROR, "Unknown V4L2 pixel format equivalent for %s\n",
68 av_get_pix_fmt_name(par->format));
69 return AVERROR(EINVAL);
70 }
71
72 if (ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
73 res = AVERROR(errno);
74 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n", av_err2str(res));
75 return res;
76 }
77
78 fmt.fmt.pix.width = par->width;
79 fmt.fmt.pix.height = par->height;
80 fmt.fmt.pix.pixelformat = v4l2_pixfmt;
81 fmt.fmt.pix.sizeimage = av_image_get_buffer_size(par->format, par->width, par->height, 1);
82
83 if (ioctl(s->fd, VIDIOC_S_FMT, &fmt) < 0) {
84 res = AVERROR(errno);
85 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_S_FMT): %s\n", av_err2str(res));
86 return res;
87 }
88
89 return res;
90 }
91
write_packet(AVFormatContext * s1,AVPacket * pkt)92 static int write_packet(AVFormatContext *s1, AVPacket *pkt)
93 {
94 const V4L2Context *s = s1->priv_data;
95 if (write(s->fd, pkt->data, pkt->size) == -1)
96 return AVERROR(errno);
97 return 0;
98 }
99
write_trailer(AVFormatContext * s1)100 static int write_trailer(AVFormatContext *s1)
101 {
102 const V4L2Context *s = s1->priv_data;
103 close(s->fd);
104 return 0;
105 }
106
107 static const AVClass v4l2_class = {
108 .class_name = "V4L2 outdev",
109 .item_name = av_default_item_name,
110 .version = LIBAVUTIL_VERSION_INT,
111 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT,
112 };
113
114 const AVOutputFormat ff_v4l2_muxer = {
115 .name = "video4linux2,v4l2",
116 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 output device"),
117 .priv_data_size = sizeof(V4L2Context),
118 .audio_codec = AV_CODEC_ID_NONE,
119 .video_codec = AV_CODEC_ID_RAWVIDEO,
120 .write_header = write_header,
121 .write_packet = write_packet,
122 .write_trailer = write_trailer,
123 .flags = AVFMT_NOFILE,
124 .priv_class = &v4l2_class,
125 };
126