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  • only in /asuswrt-rt-n18u-9.0.0.4.380.2695/release/src-rt-6.x.4708/router/ffmpeg/libavdevice/
1/*
2 * Linux video grab interface
3 * Copyright (c) 2000,2001 Fabrice Bellard
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#undef __STRICT_ANSI__ //workaround due to broken kernel headers
23#include "config.h"
24#include "libavutil/rational.h"
25#include "libavformat/avformat.h"
26#include "libavcodec/dsputil.h"
27#include <unistd.h>
28#include <fcntl.h>
29#include <sys/ioctl.h>
30#include <sys/mman.h>
31#include <sys/time.h>
32#define _LINUX_TIME_H 1
33#include <linux/videodev.h>
34#include <time.h>
35#include <strings.h>
36
37typedef struct {
38    int fd;
39    int frame_format; /* see VIDEO_PALETTE_xxx */
40    int use_mmap;
41    AVRational time_base;
42    int64_t time_frame;
43    int frame_size;
44    struct video_capability video_cap;
45    struct video_audio audio_saved;
46    struct video_window video_win;
47    uint8_t *video_buf;
48    struct video_mbuf gb_buffers;
49    struct video_mmap gb_buf;
50    int gb_frame;
51} VideoData;
52
53static const struct {
54    int palette;
55    int depth;
56    enum PixelFormat pix_fmt;
57} video_formats [] = {
58    {.palette = VIDEO_PALETTE_YUV420P, .depth = 12, .pix_fmt = PIX_FMT_YUV420P },
59    {.palette = VIDEO_PALETTE_YUV422,  .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
60    {.palette = VIDEO_PALETTE_UYVY,    .depth = 16, .pix_fmt = PIX_FMT_UYVY422 },
61    {.palette = VIDEO_PALETTE_YUYV,    .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
62    /* NOTE: v4l uses BGR24, not RGB24 */
63    {.palette = VIDEO_PALETTE_RGB24,   .depth = 24, .pix_fmt = PIX_FMT_BGR24   },
64    {.palette = VIDEO_PALETTE_RGB565,  .depth = 16, .pix_fmt = PIX_FMT_BGR565  },
65    {.palette = VIDEO_PALETTE_GREY,    .depth = 8,  .pix_fmt = PIX_FMT_GRAY8   },
66};
67
68
69static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
70{
71    VideoData *s = s1->priv_data;
72    AVStream *st;
73    int video_fd;
74    int desired_palette, desired_depth;
75    struct video_tuner tuner;
76    struct video_audio audio;
77    struct video_picture pict;
78    int j;
79    int vformat_num = FF_ARRAY_ELEMS(video_formats);
80
81    if (ap->time_base.den <= 0) {
82        av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);
83        return -1;
84    }
85    s->time_base = ap->time_base;
86
87    s->video_win.width = ap->width;
88    s->video_win.height = ap->height;
89
90    st = av_new_stream(s1, 0);
91    if (!st)
92        return AVERROR(ENOMEM);
93    av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
94
95    video_fd = open(s1->filename, O_RDWR);
96    if (video_fd < 0) {
97        av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno));
98        goto fail;
99    }
100
101    if (ioctl(video_fd, VIDIOCGCAP, &s->video_cap) < 0) {
102        av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno));
103        goto fail;
104    }
105
106    if (!(s->video_cap.type & VID_TYPE_CAPTURE)) {
107        av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n");
108        goto fail;
109    }
110
111    /* no values set, autodetect them */
112    if (s->video_win.width <= 0 || s->video_win.height <= 0) {
113        if (ioctl(video_fd, VIDIOCGWIN, &s->video_win, sizeof(s->video_win)) < 0) {
114            av_log(s1, AV_LOG_ERROR, "VIDIOCGWIN: %s\n", strerror(errno));
115            goto fail;
116        }
117    }
118
119    if(avcodec_check_dimensions(s1, s->video_win.width, s->video_win.height) < 0)
120        return -1;
121
122    desired_palette = -1;
123    desired_depth = -1;
124    for (j = 0; j < vformat_num; j++) {
125        if (ap->pix_fmt == video_formats[j].pix_fmt) {
126            desired_palette = video_formats[j].palette;
127            desired_depth = video_formats[j].depth;
128            break;
129        }
130    }
131
132    /* set tv standard */
133    if (ap->standard && !ioctl(video_fd, VIDIOCGTUNER, &tuner)) {
134        if (!strcasecmp(ap->standard, "pal"))
135            tuner.mode = VIDEO_MODE_PAL;
136        else if (!strcasecmp(ap->standard, "secam"))
137            tuner.mode = VIDEO_MODE_SECAM;
138        else
139            tuner.mode = VIDEO_MODE_NTSC;
140        ioctl(video_fd, VIDIOCSTUNER, &tuner);
141    }
142
143    /* unmute audio */
144    audio.audio = 0;
145    ioctl(video_fd, VIDIOCGAUDIO, &audio);
146    memcpy(&s->audio_saved, &audio, sizeof(audio));
147    audio.flags &= ~VIDEO_AUDIO_MUTE;
148    ioctl(video_fd, VIDIOCSAUDIO, &audio);
149
150    ioctl(video_fd, VIDIOCGPICT, &pict);
151#if 0
152    printf("v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
153           pict.colour,
154           pict.hue,
155           pict.brightness,
156           pict.contrast,
157           pict.whiteness);
158#endif
159    /* try to choose a suitable video format */
160    pict.palette = desired_palette;
161    pict.depth= desired_depth;
162    if (desired_palette == -1 || ioctl(video_fd, VIDIOCSPICT, &pict) < 0) {
163        for (j = 0; j < vformat_num; j++) {
164            pict.palette = video_formats[j].palette;
165            pict.depth = video_formats[j].depth;
166            if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict))
167                break;
168        }
169        if (j >= vformat_num)
170            goto fail1;
171    }
172
173    if (ioctl(video_fd, VIDIOCGMBUF, &s->gb_buffers) < 0) {
174        /* try to use read based access */
175        int val;
176
177        s->video_win.x = 0;
178        s->video_win.y = 0;
179        s->video_win.chromakey = -1;
180        s->video_win.flags = 0;
181
182        if (ioctl(video_fd, VIDIOCSWIN, s->video_win) < 0) {
183            av_log(s1, AV_LOG_ERROR, "VIDIOCSWIN: %s\n", strerror(errno));
184            goto fail;
185        }
186
187        s->frame_format = pict.palette;
188
189        val = 1;
190        if (ioctl(video_fd, VIDIOCCAPTURE, &val) < 0) {
191            av_log(s1, AV_LOG_ERROR, "VIDIOCCAPTURE: %s\n", strerror(errno));
192            goto fail;
193        }
194
195        s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
196        s->use_mmap = 0;
197    } else {
198        s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_SHARED, video_fd, 0);
199        if ((unsigned char*)-1 == s->video_buf) {
200            s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_PRIVATE, video_fd, 0);
201            if ((unsigned char*)-1 == s->video_buf) {
202                av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
203                goto fail;
204            }
205        }
206        s->gb_frame = 0;
207        s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
208
209        /* start to grab the first frame */
210        s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames;
211        s->gb_buf.height = s->video_win.height;
212        s->gb_buf.width = s->video_win.width;
213        s->gb_buf.format = pict.palette;
214
215        if (ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
216            if (errno != EAGAIN) {
217            fail1:
218                av_log(s1, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
219            } else {
220                av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not receive any video signal\n");
221            }
222            goto fail;
223        }
224        for (j = 1; j < s->gb_buffers.frames; j++) {
225          s->gb_buf.frame = j;
226          ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
227        }
228        s->frame_format = s->gb_buf.format;
229        s->use_mmap = 1;
230    }
231
232    for (j = 0; j < vformat_num; j++) {
233        if (s->frame_format == video_formats[j].palette) {
234            s->frame_size = s->video_win.width * s->video_win.height * video_formats[j].depth / 8;
235            st->codec->pix_fmt = video_formats[j].pix_fmt;
236            break;
237        }
238    }
239
240    if (j >= vformat_num)
241        goto fail;
242
243    s->fd = video_fd;
244
245    st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
246    st->codec->codec_id = CODEC_ID_RAWVIDEO;
247    st->codec->width = s->video_win.width;
248    st->codec->height = s->video_win.height;
249    st->codec->time_base = s->time_base;
250    st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
251
252    return 0;
253 fail:
254    if (video_fd >= 0)
255        close(video_fd);
256    return AVERROR(EIO);
257}
258
259static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)
260{
261    uint8_t *ptr;
262
263    while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 &&
264           (errno == EAGAIN || errno == EINTR));
265
266    ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];
267    memcpy(buf, ptr, s->frame_size);
268
269    /* Setup to capture the next frame */
270    s->gb_buf.frame = s->gb_frame;
271    if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
272        if (errno == EAGAIN)
273            av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n");
274        else
275            av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
276        return AVERROR(EIO);
277    }
278
279    /* This is now the grabbing frame */
280    s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames;
281
282    return s->frame_size;
283}
284
285static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
286{
287    VideoData *s = s1->priv_data;
288    int64_t curtime, delay;
289    struct timespec ts;
290
291    /* Calculate the time of the next frame */
292    s->time_frame += INT64_C(1000000);
293
294    /* wait based on the frame rate */
295    for(;;) {
296        curtime = av_gettime();
297        delay = s->time_frame * s->time_base.num / s->time_base.den - curtime;
298        if (delay <= 0) {
299            if (delay < INT64_C(-1000000) * s->time_base.num / s->time_base.den) {
300                /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */
301                s->time_frame += INT64_C(1000000);
302            }
303            break;
304        }
305        ts.tv_sec = delay / 1000000;
306        ts.tv_nsec = (delay % 1000000) * 1000;
307        nanosleep(&ts, NULL);
308    }
309
310    if (av_new_packet(pkt, s->frame_size) < 0)
311        return AVERROR(EIO);
312
313    pkt->pts = curtime;
314
315    /* read one frame */
316    if (s->use_mmap) {
317        return v4l_mm_read_picture(s, pkt->data);
318    } else {
319        if (read(s->fd, pkt->data, pkt->size) != pkt->size)
320            return AVERROR(EIO);
321        return s->frame_size;
322    }
323}
324
325static int grab_read_close(AVFormatContext *s1)
326{
327    VideoData *s = s1->priv_data;
328
329    if (s->use_mmap)
330        munmap(s->video_buf, s->gb_buffers.size);
331
332    /* mute audio. we must force it because the BTTV driver does not
333       return its state correctly */
334    s->audio_saved.flags |= VIDEO_AUDIO_MUTE;
335    ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved);
336
337    close(s->fd);
338    return 0;
339}
340
341AVInputFormat v4l_demuxer = {
342    "video4linux",
343    NULL_IF_CONFIG_SMALL("Video4Linux device grab"),
344    sizeof(VideoData),
345    NULL,
346    grab_read_header,
347    grab_read_packet,
348    grab_read_close,
349    .flags = AVFMT_NOFILE,
350};
351