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"
29 static av_cold int write_header(AVFormatContext *s1)
31 int res = 0, flags = O_RDWR;
32 struct v4l2_format fmt = {
33 .type = V4L2_BUF_TYPE_VIDEO_OUTPUT
35 V4L2Context *s = s1->priv_data;
36 AVCodecContext *enc_ctx;
39 if (s1->flags & AVFMT_FLAG_NONBLOCK)
42 s->fd = open(s1->filename, flags);
45 av_log(s1, AV_LOG_ERROR, "Unable to open V4L2 device '%s'\n", s1->filename);
49 if (s1->nb_streams != 1 ||
50 s1->streams[0]->codec->codec_type != AVMEDIA_TYPE_VIDEO ||
51 s1->streams[0]->codec->codec_id != AV_CODEC_ID_RAWVIDEO) {
52 av_log(s1, AV_LOG_ERROR,
53 "V4L2 output device supports only a single raw video stream\n");
54 return AVERROR(EINVAL);
57 enc_ctx = s1->streams[0]->codec;
59 v4l2_pixfmt = avpriv_fmt_ff2v4l(enc_ctx->pix_fmt, AV_CODEC_ID_RAWVIDEO);
60 if (!v4l2_pixfmt) { // XXX: try to force them one by one?
61 av_log(s1, AV_LOG_ERROR, "Unknown V4L2 pixel format equivalent for %s\n",
62 av_get_pix_fmt_name(enc_ctx->pix_fmt));
63 return AVERROR(EINVAL);
66 if (ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
68 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n", av_err2str(res));
72 fmt.fmt.pix.width = enc_ctx->width;
73 fmt.fmt.pix.height = enc_ctx->height;
74 fmt.fmt.pix.pixelformat = v4l2_pixfmt;
75 fmt.fmt.pix.sizeimage = av_image_get_buffer_size(enc_ctx->pix_fmt, enc_ctx->width, enc_ctx->height, 1);
77 if (ioctl(s->fd, VIDIOC_S_FMT, &fmt) < 0) {
79 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_S_FMT): %s\n", av_err2str(res));
86 static int write_packet(AVFormatContext *s1, AVPacket *pkt)
88 const V4L2Context *s = s1->priv_data;
89 if (write(s->fd, pkt->data, pkt->size) == -1)
90 return AVERROR(errno);
94 static int write_trailer(AVFormatContext *s1)
96 const V4L2Context *s = s1->priv_data;
101 static const AVClass v4l2_class = {
102 .class_name = "V4L2 outdev",
103 .item_name = av_default_item_name,
104 .version = LIBAVUTIL_VERSION_INT,
105 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_OUTPUT,
108 AVOutputFormat ff_v4l2_muxer = {
110 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 output device"),
111 .priv_data_size = sizeof(V4L2Context),
112 .audio_codec = AV_CODEC_ID_NONE,
113 .video_codec = AV_CODEC_ID_RAWVIDEO,
114 .write_header = write_header,
115 .write_packet = write_packet,
116 .write_trailer = write_trailer,
117 .flags = AVFMT_NOFILE,
118 .priv_class = &v4l2_class,