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
write_header(AVFormatContext * s1)29 static av_cold int write_header(AVFormatContext *s1)
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) {
51 av_log(s1, AV_LOG_ERROR,
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",
66 av_get_pix_fmt_name(par->format));
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
write_packet(AVFormatContext * s1,AVPacket * pkt)90 static int write_packet(AVFormatContext *s1, AVPacket *pkt)
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
write_trailer(AVFormatContext * s1)98 static int write_trailer(AVFormatContext *s1)
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,
109 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT,
110 };
111
112 AVOutputFormat ff_v4l2_muxer = {
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,
118 .write_header = write_header,
119 .write_packet = write_packet,
120 .write_trailer = write_trailer,
121 .flags = AVFMT_NOFILE,
122 .priv_class = &v4l2_class,
123 };
124