summaryrefslogtreecommitdiffstats
path: root/libavdevice/v4l.c
blob: 1be7adf49d920ad3a480b7080badd6717525b3b9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
/*
 * Linux video grab interface
 * Copyright (c) 2000,2001 Fabrice Bellard
 *
 * This file is part of Libav.
 *
 * Libav is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * Libav is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with Libav; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "avdevice.h"

#if FF_API_V4L

#undef __STRICT_ANSI__ //workaround due to broken kernel headers
#include "config.h"
#include "libavutil/rational.h"
#include "libavutil/imgutils.h"
#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "libavformat/avformat.h"
#include "libavcodec/dsputil.h"
#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/time.h>
#define _LINUX_TIME_H 1
#include <linux/videodev.h>
#include <time.h>
#include <strings.h>

typedef struct {
    AVClass *class;
    int fd;
    int frame_format; /* see VIDEO_PALETTE_xxx */
    int use_mmap;
    AVRational time_base;
    int64_t time_frame;
    int frame_size;
    struct video_capability video_cap;
    struct video_audio audio_saved;
    struct video_window video_win;
    uint8_t *video_buf;
    struct video_mbuf gb_buffers;
    struct video_mmap gb_buf;
    int gb_frame;
    int standard;
} VideoData;

static const struct {
    int palette;
    int depth;
    enum PixelFormat pix_fmt;
} video_formats [] = {
    {.palette = VIDEO_PALETTE_YUV420P, .depth = 12, .pix_fmt = PIX_FMT_YUV420P },
    {.palette = VIDEO_PALETTE_YUV422,  .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
    {.palette = VIDEO_PALETTE_UYVY,    .depth = 16, .pix_fmt = PIX_FMT_UYVY422 },
    {.palette = VIDEO_PALETTE_YUYV,    .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
    /* NOTE: v4l uses BGR24, not RGB24 */
    {.palette = VIDEO_PALETTE_RGB24,   .depth = 24, .pix_fmt = PIX_FMT_BGR24   },
    {.palette = VIDEO_PALETTE_RGB565,  .depth = 16, .pix_fmt = PIX_FMT_BGR565  },
    {.palette = VIDEO_PALETTE_GREY,    .depth = 8,  .pix_fmt = PIX_FMT_GRAY8   },
};


static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
{
    VideoData *s = s1->priv_data;
    AVStream *st;
    int video_fd;
    int desired_palette, desired_depth;
    struct video_tuner tuner;
    struct video_audio audio;
    struct video_picture pict;
    int j;
    int vformat_num = FF_ARRAY_ELEMS(video_formats);

    av_log(s1, AV_LOG_WARNING, "V4L input device is deprecated and will be removed in the next release.");

    if (ap->time_base.den <= 0) {
        av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);
        return -1;
    }
    s->time_base = ap->time_base;

    s->video_win.width = ap->width;
    s->video_win.height = ap->height;

    st = av_new_stream(s1, 0);
    if (!st)
        return AVERROR(ENOMEM);
    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */

    video_fd = open(s1->filename, O_RDWR);
    if (video_fd < 0) {
        av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno));
        goto fail;
    }

    if (ioctl(video_fd, VIDIOCGCAP, &s->video_cap) < 0) {
        av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno));
        goto fail;
    }

    if (!(s->video_cap.type & VID_TYPE_CAPTURE)) {
        av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n");
        goto fail;
    }

    /* no values set, autodetect them */
    if (s->video_win.width <= 0 || s->video_win.height <= 0) {
        if (ioctl(video_fd, VIDIOCGWIN, &s->video_win, sizeof(s->video_win)) < 0) {
            av_log(s1, AV_LOG_ERROR, "VIDIOCGWIN: %s\n", strerror(errno));
            goto fail;
        }
    }

    if(av_image_check_size(s->video_win.width, s->video_win.height, 0, s1) < 0)
        return -1;

    desired_palette = -1;
    desired_depth = -1;
    for (j = 0; j < vformat_num; j++) {
        if (ap->pix_fmt == video_formats[j].pix_fmt) {
            desired_palette = video_formats[j].palette;
            desired_depth = video_formats[j].depth;
            break;
        }
    }

    /* set tv standard */
    if (!ioctl(video_fd, VIDIOCGTUNER, &tuner)) {
#if FF_API_FORMAT_PARAMETERS
        if (ap->standard) {
            if (!strcasecmp(ap->standard, "pal"))
                s->standard = VIDEO_MODE_PAL;
            else if (!strcasecmp(ap->standard, "secam"))
                s->standard = VIDEO_MODE_SECAM;
            else
                s->standard = VIDEO_MODE_NTSC;
        }
#endif
        tuner.mode = s->standard;
        ioctl(video_fd, VIDIOCSTUNER, &tuner);
    }

    /* unmute audio */
    audio.audio = 0;
    ioctl(video_fd, VIDIOCGAUDIO, &audio);
    memcpy(&s->audio_saved, &audio, sizeof(audio));
    audio.flags &= ~VIDEO_AUDIO_MUTE;
    ioctl(video_fd, VIDIOCSAUDIO, &audio);

    ioctl(video_fd, VIDIOCGPICT, &pict);
    av_dlog(s1, "v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
            pict.colour, pict.hue, pict.brightness, pict.contrast, pict.whiteness);
    /* try to choose a suitable video format */
    pict.palette = desired_palette;
    pict.depth= desired_depth;
    if (desired_palette == -1 || ioctl(video_fd, VIDIOCSPICT, &pict) < 0) {
        for (j = 0; j < vformat_num; j++) {
            pict.palette = video_formats[j].palette;
            pict.depth = video_formats[j].depth;
            if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict))
                break;
        }
        if (j >= vformat_num)
            goto fail1;
    }

    if (ioctl(video_fd, VIDIOCGMBUF, &s->gb_buffers) < 0) {
        /* try to use read based access */
        int val;

        s->video_win.x = 0;
        s->video_win.y = 0;
        s->video_win.chromakey = -1;
        s->video_win.flags = 0;

        if (ioctl(video_fd, VIDIOCSWIN, s->video_win) < 0) {
            av_log(s1, AV_LOG_ERROR, "VIDIOCSWIN: %s\n", strerror(errno));
            goto fail;
        }

        s->frame_format = pict.palette;

        val = 1;
        if (ioctl(video_fd, VIDIOCCAPTURE, &val) < 0) {
            av_log(s1, AV_LOG_ERROR, "VIDIOCCAPTURE: %s\n", strerror(errno));
            goto fail;
        }

        s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
        s->use_mmap = 0;
    } else {
        s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_SHARED, video_fd, 0);
        if ((unsigned char*)-1 == s->video_buf) {
            s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_PRIVATE, video_fd, 0);
            if ((unsigned char*)-1 == s->video_buf) {
                av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
                goto fail;
            }
        }
        s->gb_frame = 0;
        s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;

        /* start to grab the first frame */
        s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames;
        s->gb_buf.height = s->video_win.height;
        s->gb_buf.width = s->video_win.width;
        s->gb_buf.format = pict.palette;

        if (ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
            if (errno != EAGAIN) {
            fail1:
                av_log(s1, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
            } else {
                av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not receive any video signal\n");
            }
            goto fail;
        }
        for (j = 1; j < s->gb_buffers.frames; j++) {
          s->gb_buf.frame = j;
          ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
        }
        s->frame_format = s->gb_buf.format;
        s->use_mmap = 1;
    }

    for (j = 0; j < vformat_num; j++) {
        if (s->frame_format == video_formats[j].palette) {
            s->frame_size = s->video_win.width * s->video_win.height * video_formats[j].depth / 8;
            st->codec->pix_fmt = video_formats[j].pix_fmt;
            break;
        }
    }

    if (j >= vformat_num)
        goto fail;

    s->fd = video_fd;

    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
    st->codec->codec_id = CODEC_ID_RAWVIDEO;
    st->codec->width = s->video_win.width;
    st->codec->height = s->video_win.height;
    st->codec->time_base = s->time_base;
    st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;

    return 0;
 fail:
    if (video_fd >= 0)
        close(video_fd);
    return AVERROR(EIO);
}

static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)
{
    uint8_t *ptr;

    while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 &&
           (errno == EAGAIN || errno == EINTR));

    ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];
    memcpy(buf, ptr, s->frame_size);

    /* Setup to capture the next frame */
    s->gb_buf.frame = s->gb_frame;
    if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
        if (errno == EAGAIN)
            av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n");
        else
            av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
        return AVERROR(EIO);
    }

    /* This is now the grabbing frame */
    s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames;

    return s->frame_size;
}

static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
{
    VideoData *s = s1->priv_data;
    int64_t curtime, delay;
    struct timespec ts;

    /* Calculate the time of the next frame */
    s->time_frame += INT64_C(1000000);

    /* wait based on the frame rate */
    for(;;) {
        curtime = av_gettime();
        delay = s->time_frame * s->time_base.num / s->time_base.den - curtime;
        if (delay <= 0) {
            if (delay < INT64_C(-1000000) * s->time_base.num / s->time_base.den) {
                /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */
                s->time_frame += INT64_C(1000000);
            }
            break;
        }
        ts.tv_sec = delay / 1000000;
        ts.tv_nsec = (delay % 1000000) * 1000;
        nanosleep(&ts, NULL);
    }

    if (av_new_packet(pkt, s->frame_size) < 0)
        return AVERROR(EIO);

    pkt->pts = curtime;

    /* read one frame */
    if (s->use_mmap) {
        return v4l_mm_read_picture(s, pkt->data);
    } else {
        if (read(s->fd, pkt->data, pkt->size) != pkt->size)
            return AVERROR(EIO);
        return s->frame_size;
    }
}

static int grab_read_close(AVFormatContext *s1)
{
    VideoData *s = s1->priv_data;

    if (s->use_mmap)
        munmap(s->video_buf, s->gb_buffers.size);

    /* mute audio. we must force it because the BTTV driver does not
       return its state correctly */
    s->audio_saved.flags |= VIDEO_AUDIO_MUTE;
    ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved);

    close(s->fd);
    return 0;
}

static const AVOption options[] = {
    { "standard", "", offsetof(VideoData, standard), FF_OPT_TYPE_INT, {.dbl = VIDEO_MODE_NTSC}, VIDEO_MODE_PAL, VIDEO_MODE_NTSC, AV_OPT_FLAG_DECODING_PARAM, "standard" },
    { "PAL",   "", 0, FF_OPT_TYPE_CONST, {.dbl = VIDEO_MODE_PAL},   0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
    { "SECAM", "", 0, FF_OPT_TYPE_CONST, {.dbl = VIDEO_MODE_SECAM}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
    { "NTSC",  "", 0, FF_OPT_TYPE_CONST, {.dbl = VIDEO_MODE_NTSC},  0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
    { NULL },
};

static const AVClass v4l_class = {
    .class_name = "V4L indev",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
};

AVInputFormat ff_v4l_demuxer = {
    "video4linux",
    NULL_IF_CONFIG_SMALL("Video4Linux device grab"),
    sizeof(VideoData),
    NULL,
    grab_read_header,
    grab_read_packet,
    grab_read_close,
    .flags = AVFMT_NOFILE,
    .priv_class = &v4l_class,
};
#endif  /* FF_API_V4L */
OpenPOWER on IntegriCloud