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 26typedef struct { 27 AVClass *class; 28 int fd; 29} V4L2Context; 30 31static 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 92static 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 100static int write_trailer(AVFormatContext *s1) 101{ 102 const V4L2Context *s = s1->priv_data; 103 close(s->fd); 104 return 0; 105} 106 107static 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 114const 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