2 * Copyright (c) 2013 Clément Bœsch
4 * This file is part of FFmpeg.
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.
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.
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
21 #include "v4l2-common.h"
28 static av_cold int write_header(AVFormatContext *s1)
30 int res = 0, flags = O_RDWR;
31 struct v4l2_format fmt = {
32 .type = V4L2_BUF_TYPE_VIDEO_OUTPUT
34 V4L2Context *s = s1->priv_data;
35 AVCodecContext *enc_ctx;
38 if (s1->flags & AVFMT_FLAG_NONBLOCK)
41 s->fd = open(s1->filename, flags);
44 av_log(s1, AV_LOG_ERROR, "Unable to open V4L2 device '%s'\n", s1->filename);
48 if (s1->nb_streams != 1 ||
49 s1->streams[0]->codec->codec_type != AVMEDIA_TYPE_VIDEO ||
50 s1->streams[0]->codec->codec_id != AV_CODEC_ID_RAWVIDEO) {
51 av_log(s1, AV_LOG_ERROR,
52 "V4L2 output device supports only a single raw video stream\n");
53 return AVERROR(EINVAL);
56 enc_ctx = s1->streams[0]->codec;
58 v4l2_pixfmt = avpriv_fmt_ff2v4l(enc_ctx->pix_fmt, AV_CODEC_ID_RAWVIDEO);
59 if (!v4l2_pixfmt) { // XXX: try to force them one by one?
60 av_log(s1, AV_LOG_ERROR, "Unknown V4L2 pixel format equivalent for %s\n",
61 av_get_pix_fmt_name(enc_ctx->pix_fmt));
62 return AVERROR(EINVAL);
65 if (ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
67 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n", av_err2str(res));
71 fmt.fmt.pix.width = enc_ctx->width;
72 fmt.fmt.pix.height = enc_ctx->height;
73 fmt.fmt.pix.pixelformat = v4l2_pixfmt;
74 fmt.fmt.pix.sizeimage = av_image_get_buffer_size(enc_ctx->pix_fmt, enc_ctx->width, enc_ctx->height, 1);
76 if (ioctl(s->fd, VIDIOC_S_FMT, &fmt) < 0) {
78 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_S_FMT): %s\n", av_err2str(res));
85 static int write_packet(AVFormatContext *s1, AVPacket *pkt)
87 const V4L2Context *s = s1->priv_data;
88 if (write(s->fd, pkt->data, pkt->size) == -1)
89 return AVERROR(errno);
93 static int write_trailer(AVFormatContext *s1)
95 const V4L2Context *s = s1->priv_data;
100 AVOutputFormat ff_v4l2_muxer = {
102 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 output device"),
103 .priv_data_size = sizeof(V4L2Context),
104 .audio_codec = AV_CODEC_ID_NONE,
105 .video_codec = AV_CODEC_ID_RAWVIDEO,
106 .write_header = write_header,
107 .write_packet = write_packet,
108 .write_trailer = write_trailer,
109 .flags = AVFMT_NOFILE,