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