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path: root/libavdevice/v4l.c (plain)
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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#include "avdevice.h"
23
24#undef __STRICT_ANSI__ //workaround due to broken kernel headers
25#include "config.h"
26#include "libavutil/rational.h"
27#include "libavutil/imgutils.h"
28#include "libavutil/internal.h"
29#include "libavutil/log.h"
30#include "libavutil/opt.h"
31#include "libavformat/internal.h"
32#include "libavcodec/dsputil.h"
33#include <unistd.h>
34#include <fcntl.h>
35#include <sys/ioctl.h>
36#include <sys/mman.h>
37#include <sys/time.h>
38#define _LINUX_TIME_H 1
39#include <linux/videodev.h>
40#include <time.h>
41
42typedef struct {
43 AVClass *class;
44 int fd;
45 int frame_format; /* see VIDEO_PALETTE_xxx */
46 int use_mmap;
47 AVRational time_base;
48 int64_t time_frame;
49 int frame_size;
50 struct video_capability video_cap;
51 struct video_audio audio_saved;
52 struct video_window video_win;
53 uint8_t *video_buf;
54 struct video_mbuf gb_buffers;
55 struct video_mmap gb_buf;
56 int gb_frame;
57 int standard;
58} VideoData;
59
60static const struct {
61 int palette;
62 int depth;
63 enum AVPixelFormat pix_fmt;
64} video_formats [] = {
65 {.palette = VIDEO_PALETTE_YUV420P, .depth = 12, .pix_fmt = AV_PIX_FMT_YUV420P },
66 {.palette = VIDEO_PALETTE_YUV422, .depth = 16, .pix_fmt = AV_PIX_FMT_YUYV422 },
67 {.palette = VIDEO_PALETTE_UYVY, .depth = 16, .pix_fmt = AV_PIX_FMT_UYVY422 },
68 {.palette = VIDEO_PALETTE_YUYV, .depth = 16, .pix_fmt = AV_PIX_FMT_YUYV422 },
69 /* NOTE: v4l uses BGR24, not RGB24 */
70 {.palette = VIDEO_PALETTE_RGB24, .depth = 24, .pix_fmt = AV_PIX_FMT_BGR24 },
71 {.palette = VIDEO_PALETTE_RGB565, .depth = 16, .pix_fmt = AV_PIX_FMT_BGR565 },
72 {.palette = VIDEO_PALETTE_GREY, .depth = 8, .pix_fmt = AV_PIX_FMT_GRAY8 },
73};
74
75
76static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
77{
78 VideoData *s = s1->priv_data;
79 AVStream *st;
80 int video_fd;
81 int desired_palette, desired_depth;
82 struct video_tuner tuner;
83 struct video_audio audio;
84 struct video_picture pict;
85 int j;
86 int vformat_num = FF_ARRAY_ELEMS(video_formats);
87
88 av_log(s1, AV_LOG_WARNING, "V4L input device is deprecated and will be removed in the next release.");
89
90 if (ap->time_base.den <= 0) {
91 av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);
92 return -1;
93 }
94 s->time_base = ap->time_base;
95
96 s->video_win.width = ap->width;
97 s->video_win.height = ap->height;
98
99 st = avformat_new_stream(s1, NULL);
100 if (!st)
101 return AVERROR(ENOMEM);
102 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
103
104 video_fd = open(s1->filename, O_RDWR);
105 if (video_fd < 0) {
106 av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno));
107 goto fail;
108 }
109
110 if (ioctl(video_fd, VIDIOCGCAP, &s->video_cap) < 0) {
111 av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno));
112 goto fail;
113 }
114
115 if (!(s->video_cap.type & VID_TYPE_CAPTURE)) {
116 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n");
117 goto fail;
118 }
119
120 /* no values set, autodetect them */
121 if (s->video_win.width <= 0 || s->video_win.height <= 0) {
122 if (ioctl(video_fd, VIDIOCGWIN, &s->video_win, sizeof(s->video_win)) < 0) {
123 av_log(s1, AV_LOG_ERROR, "VIDIOCGWIN: %s\n", strerror(errno));
124 goto fail;
125 }
126 }
127
128 if(av_image_check_size(s->video_win.width, s->video_win.height, 0, s1) < 0)
129 return -1;
130
131 desired_palette = -1;
132 desired_depth = -1;
133 for (j = 0; j < vformat_num; j++) {
134 if (ap->pix_fmt == video_formats[j].pix_fmt) {
135 desired_palette = video_formats[j].palette;
136 desired_depth = video_formats[j].depth;
137 break;
138 }
139 }
140
141 /* set tv standard */
142 if (!ioctl(video_fd, VIDIOCGTUNER, &tuner)) {
143 tuner.mode = s->standard;
144 ioctl(video_fd, VIDIOCSTUNER, &tuner);
145 }
146
147 /* unmute audio */
148 audio.audio = 0;
149 ioctl(video_fd, VIDIOCGAUDIO, &audio);
150 memcpy(&s->audio_saved, &audio, sizeof(audio));
151 audio.flags &= ~VIDEO_AUDIO_MUTE;
152 ioctl(video_fd, VIDIOCSAUDIO, &audio);
153
154 ioctl(video_fd, VIDIOCGPICT, &pict);
155 ff_dlog(s1, "v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
156 pict.colour, pict.hue, pict.brightness, pict.contrast, pict.whiteness);
157 /* try to choose a suitable video format */
158 pict.palette = desired_palette;
159 pict.depth= desired_depth;
160 if (desired_palette == -1 || ioctl(video_fd, VIDIOCSPICT, &pict) < 0) {
161 for (j = 0; j < vformat_num; j++) {
162 pict.palette = video_formats[j].palette;
163 pict.depth = video_formats[j].depth;
164 if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict))
165 break;
166 }
167 if (j >= vformat_num)
168 goto fail1;
169 }
170
171 if (ioctl(video_fd, VIDIOCGMBUF, &s->gb_buffers) < 0) {
172 /* try to use read based access */
173 int val;
174
175 s->video_win.x = 0;
176 s->video_win.y = 0;
177 s->video_win.chromakey = -1;
178 s->video_win.flags = 0;
179
180 if (ioctl(video_fd, VIDIOCSWIN, s->video_win) < 0) {
181 av_log(s1, AV_LOG_ERROR, "VIDIOCSWIN: %s\n", strerror(errno));
182 goto fail;
183 }
184
185 s->frame_format = pict.palette;
186
187 val = 1;
188 if (ioctl(video_fd, VIDIOCCAPTURE, &val) < 0) {
189 av_log(s1, AV_LOG_ERROR, "VIDIOCCAPTURE: %s\n", strerror(errno));
190 goto fail;
191 }
192
193 s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
194 s->use_mmap = 0;
195 } else {
196 s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_SHARED, video_fd, 0);
197 if ((unsigned char*)-1 == s->video_buf) {
198 s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_PRIVATE, video_fd, 0);
199 if ((unsigned char*)-1 == s->video_buf) {
200 av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
201 goto fail;
202 }
203 }
204 s->gb_frame = 0;
205 s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
206
207 /* start to grab the first frame */
208 s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames;
209 s->gb_buf.height = s->video_win.height;
210 s->gb_buf.width = s->video_win.width;
211 s->gb_buf.format = pict.palette;
212
213 if (ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
214 if (errno != EAGAIN) {
215 fail1:
216 av_log(s1, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
217 } else {
218 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not receive any video signal\n");
219 }
220 goto fail;
221 }
222 for (j = 1; j < s->gb_buffers.frames; j++) {
223 s->gb_buf.frame = j;
224 ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
225 }
226 s->frame_format = s->gb_buf.format;
227 s->use_mmap = 1;
228 }
229
230 for (j = 0; j < vformat_num; j++) {
231 if (s->frame_format == video_formats[j].palette) {
232 s->frame_size = s->video_win.width * s->video_win.height * video_formats[j].depth / 8;
233 st->codec->pix_fmt = video_formats[j].pix_fmt;
234 break;
235 }
236 }
237
238 if (j >= vformat_num)
239 goto fail;
240
241 s->fd = video_fd;
242
243 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
244 st->codec->codec_id = AV_CODEC_ID_RAWVIDEO;
245 st->codec->width = s->video_win.width;
246 st->codec->height = s->video_win.height;
247 st->codec->time_base = s->time_base;
248 st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
249
250 return 0;
251 fail:
252 if (video_fd >= 0)
253 close(video_fd);
254 return AVERROR(EIO);
255}
256
257static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)
258{
259 uint8_t *ptr;
260
261 while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 &&
262 (errno == EAGAIN || errno == EINTR));
263
264 ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];
265 memcpy(buf, ptr, s->frame_size);
266
267 /* Setup to capture the next frame */
268 s->gb_buf.frame = s->gb_frame;
269 if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
270 if (errno == EAGAIN)
271 av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n");
272 else
273 av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
274 return AVERROR(EIO);
275 }
276
277 /* This is now the grabbing frame */
278 s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames;
279
280 return s->frame_size;
281}
282
283static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
284{
285 VideoData *s = s1->priv_data;
286 int64_t curtime, delay;
287 struct timespec ts;
288
289 /* Calculate the time of the next frame */
290 s->time_frame += INT64_C(1000000);
291
292 /* wait based on the frame rate */
293 for(;;) {
294 curtime = av_gettime();
295 delay = s->time_frame * s->time_base.num / s->time_base.den - curtime;
296 if (delay <= 0) {
297 if (delay < INT64_C(-1000000) * s->time_base.num / s->time_base.den) {
298 /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */
299 s->time_frame += INT64_C(1000000);
300 }
301 break;
302 }
303 ts.tv_sec = delay / 1000000;
304 ts.tv_nsec = (delay % 1000000) * 1000;
305 nanosleep(&ts, NULL);
306 }
307
308 if (av_new_packet(pkt, s->frame_size) < 0)
309 return AVERROR(EIO);
310
311 pkt->pts = curtime;
312
313 /* read one frame */
314 if (s->use_mmap) {
315 return v4l_mm_read_picture(s, pkt->data);
316 } else {
317 if (read(s->fd, pkt->data, pkt->size) != pkt->size)
318 return AVERROR(EIO);
319 return s->frame_size;
320 }
321}
322
323static int grab_read_close(AVFormatContext *s1)
324{
325 VideoData *s = s1->priv_data;
326
327 if (s->use_mmap)
328 munmap(s->video_buf, s->gb_buffers.size);
329
330 /* mute audio. we must force it because the BTTV driver does not
331 return its state correctly */
332 s->audio_saved.flags |= VIDEO_AUDIO_MUTE;
333 ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved);
334
335 close(s->fd);
336 return 0;
337}
338
339static const AVOption options[] = {
340 { "standard", "", offsetof(VideoData, standard), AV_OPT_TYPE_INT, {.i64 = VIDEO_MODE_NTSC}, VIDEO_MODE_PAL, VIDEO_MODE_NTSC, AV_OPT_FLAG_DECODING_PARAM, "standard" },
341 { "PAL", "", 0, AV_OPT_TYPE_CONST, {.i64 = VIDEO_MODE_PAL}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
342 { "SECAM", "", 0, AV_OPT_TYPE_CONST, {.i64 = VIDEO_MODE_SECAM}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
343 { "NTSC", "", 0, AV_OPT_TYPE_CONST, {.i64 = VIDEO_MODE_NTSC}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
344 { NULL },
345};
346
347static const AVClass v4l_class = {
348 .class_name = "V4L indev",
349 .item_name = av_default_item_name,
350 .option = options,
351 .version = LIBAVUTIL_VERSION_INT,
352 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
353};
354
355AVInputFormat ff_v4l_demuxer = {
356 .name = "video4linux,v4l",
357 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux device grab"),
358 .priv_data_size = sizeof(VideoData),
359 .read_header = grab_read_header,
360 .read_packet = grab_read_packet,
361 .read_close = grab_read_close,
362 .flags = AVFMT_NOFILE,
363 .priv_class = &v4l_class,
364};
365
generated by cgit at 2024-05-17 08:35:02 (GMT)