1/* 2 * Copyright (c) 2013 Cl��ment B��sch 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 24typedef struct { 25 AVClass *class; 26 int fd; 27} V4L2Context; 28 29static 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 AVCodecContext *enc_ctx; 37 uint32_t v4l2_pixfmt; 38 39 if (s1->flags & AVFMT_FLAG_NONBLOCK) 40 flags |= O_NONBLOCK; 41 42 s->fd = open(s1->filename, 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->filename); 46 return res; 47 } 48 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); 55 } 56 57 enc_ctx = s1->streams[0]->codec; 58 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); 64 } 65 66 if (ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) { 67 res = AVERROR(errno); 68 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n", av_err2str(res)); 69 return res; 70 } 71 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); 76 77 if (ioctl(s->fd, VIDIOC_S_FMT, &fmt) < 0) { 78 res = AVERROR(errno); 79 av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_S_FMT): %s\n", av_err2str(res)); 80 return res; 81 } 82 83 return res; 84} 85 86static int write_packet(AVFormatContext *s1, AVPacket *pkt) 87{ 88 const V4L2Context *s = s1->priv_data; 89 if (write(s->fd, pkt->data, pkt->size) == -1) 90 return AVERROR(errno); 91 return 0; 92} 93 94static int write_trailer(AVFormatContext *s1) 95{ 96 const V4L2Context *s = s1->priv_data; 97 close(s->fd); 98 return 0; 99} 100 101static 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, 106}; 107 108AVOutputFormat ff_v4l2_muxer = { 109 .name = "v4l2", 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, 119}; 120