1 /*
2 * Copyright (c) 2000,2001 Fabrice Bellard
3 * Copyright (c) 2006 Luca Abeni
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 /**
23 * @file
24 * Video4Linux2 grab interface
25 *
26 * Part of this file is based on the V4L2 video capture example
27 * (http://linuxtv.org/downloads/v4l-dvb-apis/capture-example.html)
28 *
29 * Thanks to Michael Niedermayer for providing the mapping between
30 * V4L2_PIX_FMT_* and AV_PIX_FMT_*
31 */
32
33 #include <stdatomic.h>
34
35 #include "libavutil/avassert.h"
36 #include "libavutil/avstring.h"
37 #include "libavutil/imgutils.h"
38 #include "libavutil/parseutils.h"
39 #include "libavutil/pixdesc.h"
40 #include "libavutil/time.h"
41 #include "libavcodec/codec_desc.h"
42 #include "libavformat/demux.h"
43 #include "libavformat/internal.h"
44 #include "avdevice.h"
45 #include "timefilter.h"
46 #include "v4l2-common.h"
47 #include <dirent.h>
48
49 #if CONFIG_LIBV4L2
50 #include <libv4l2.h>
51 #endif
52
53 static const int desired_video_buffers = 256;
54
55 #define V4L_ALLFORMATS 3
56 #define V4L_RAWFORMATS 1
57 #define V4L_COMPFORMATS 2
58
59 /**
60 * Return timestamps to the user exactly as returned by the kernel
61 */
62 #define V4L_TS_DEFAULT 0
63 /**
64 * Autodetect the kind of timestamps returned by the kernel and convert to
65 * absolute (wall clock) timestamps.
66 */
67 #define V4L_TS_ABS 1
68 /**
69 * Assume kernel timestamps are from the monotonic clock and convert to
70 * absolute timestamps.
71 */
72 #define V4L_TS_MONO2ABS 2
73
74 /**
75 * Once the kind of timestamps returned by the kernel have been detected,
76 * the value of the timefilter (NULL or not) determines whether a conversion
77 * takes place.
78 */
79 #define V4L_TS_CONVERT_READY V4L_TS_DEFAULT
80
81 struct video_data {
82 AVClass *class;
83 int fd;
84 int pixelformat; /* V4L2_PIX_FMT_* */
85 int width, height;
86 int frame_size;
87 int interlaced;
88 int top_field_first;
89 int ts_mode;
90 TimeFilter *timefilter;
91 int64_t last_time_m;
92
93 int buffers;
94 atomic_int buffers_queued;
95 void **buf_start;
96 unsigned int *buf_len;
97 char *standard;
98 v4l2_std_id std_id;
99 int channel;
100 char *pixel_format; /**< Set by a private option. */
101 int list_format; /**< Set by a private option. */
102 int list_standard; /**< Set by a private option. */
103 char *framerate; /**< Set by a private option. */
104
105 int use_libv4l2;
106 int (*open_f)(const char *file, int oflag, ...);
107 int (*close_f)(int fd);
108 int (*dup_f)(int fd);
109 #ifdef __GLIBC__
110 int (*ioctl_f)(int fd, unsigned long int request, ...);
111 #else
112 int (*ioctl_f)(int fd, int request, ...);
113 #endif
114 ssize_t (*read_f)(int fd, void *buffer, size_t n);
115 void *(*mmap_f)(void *start, size_t length, int prot, int flags, int fd, int64_t offset);
116 int (*munmap_f)(void *_start, size_t length);
117 };
118
119 struct buff_data {
120 struct video_data *s;
121 int index;
122 };
123
device_open(AVFormatContext * ctx,const char * device_path)124 static int device_open(AVFormatContext *ctx, const char* device_path)
125 {
126 struct video_data *s = ctx->priv_data;
127 struct v4l2_capability cap;
128 int fd;
129 int err;
130 int flags = O_RDWR;
131
132 #define SET_WRAPPERS(prefix) do { \
133 s->open_f = prefix ## open; \
134 s->close_f = prefix ## close; \
135 s->dup_f = prefix ## dup; \
136 s->ioctl_f = prefix ## ioctl; \
137 s->read_f = prefix ## read; \
138 s->mmap_f = prefix ## mmap; \
139 s->munmap_f = prefix ## munmap; \
140 } while (0)
141
142 if (s->use_libv4l2) {
143 #if CONFIG_LIBV4L2
144 SET_WRAPPERS(v4l2_);
145 #else
146 av_log(ctx, AV_LOG_ERROR, "libavdevice is not built with libv4l2 support.\n");
147 return AVERROR(EINVAL);
148 #endif
149 } else {
150 SET_WRAPPERS();
151 }
152
153 #define v4l2_open s->open_f
154 #define v4l2_close s->close_f
155 #define v4l2_dup s->dup_f
156 #define v4l2_ioctl s->ioctl_f
157 #define v4l2_read s->read_f
158 #define v4l2_mmap s->mmap_f
159 #define v4l2_munmap s->munmap_f
160
161 if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
162 flags |= O_NONBLOCK;
163 }
164
165 fd = v4l2_open(device_path, flags, 0);
166 if (fd < 0) {
167 err = AVERROR(errno);
168 av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s: %s\n",
169 device_path, av_err2str(err));
170 return err;
171 }
172
173 if (v4l2_ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0) {
174 err = AVERROR(errno);
175 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
176 av_err2str(err));
177 goto fail;
178 }
179
180 av_log(ctx, AV_LOG_VERBOSE, "fd:%d capabilities:%x\n",
181 fd, cap.capabilities);
182
183 if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
184 av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
185 err = AVERROR(ENODEV);
186 goto fail;
187 }
188
189 if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
190 av_log(ctx, AV_LOG_ERROR,
191 "The device does not support the streaming I/O method.\n");
192 err = AVERROR(ENOSYS);
193 goto fail;
194 }
195
196 return fd;
197
198 fail:
199 v4l2_close(fd);
200 return err;
201 }
202
device_init(AVFormatContext * ctx,int * width,int * height,uint32_t pixelformat)203 static int device_init(AVFormatContext *ctx, int *width, int *height,
204 uint32_t pixelformat)
205 {
206 struct video_data *s = ctx->priv_data;
207 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
208 int res = 0;
209
210 fmt.fmt.pix.width = *width;
211 fmt.fmt.pix.height = *height;
212 fmt.fmt.pix.pixelformat = pixelformat;
213 fmt.fmt.pix.field = V4L2_FIELD_ANY;
214
215 /* Some drivers will fail and return EINVAL when the pixelformat
216 is not supported (even if type field is valid and supported) */
217 if (v4l2_ioctl(s->fd, VIDIOC_S_FMT, &fmt) < 0)
218 res = AVERROR(errno);
219
220 if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
221 av_log(ctx, AV_LOG_INFO,
222 "The V4L2 driver changed the video from %dx%d to %dx%d\n",
223 *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
224 *width = fmt.fmt.pix.width;
225 *height = fmt.fmt.pix.height;
226 }
227
228 if (pixelformat != fmt.fmt.pix.pixelformat) {
229 av_log(ctx, AV_LOG_DEBUG,
230 "The V4L2 driver changed the pixel format "
231 "from 0x%08X to 0x%08X\n",
232 pixelformat, fmt.fmt.pix.pixelformat);
233 res = AVERROR(EINVAL);
234 }
235
236 if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
237 av_log(ctx, AV_LOG_DEBUG,
238 "The V4L2 driver is using the interlaced mode\n");
239 s->interlaced = 1;
240 }
241
242 return res;
243 }
244
first_field(const struct video_data * s)245 static int first_field(const struct video_data *s)
246 {
247 int res;
248 v4l2_std_id std;
249
250 res = v4l2_ioctl(s->fd, VIDIOC_G_STD, &std);
251 if (res < 0)
252 return 0;
253 if (std & V4L2_STD_NTSC)
254 return 0;
255
256 return 1;
257 }
258
259 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
list_framesizes(AVFormatContext * ctx,uint32_t pixelformat)260 static void list_framesizes(AVFormatContext *ctx, uint32_t pixelformat)
261 {
262 const struct video_data *s = ctx->priv_data;
263 struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
264
265 while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
266 switch (vfse.type) {
267 case V4L2_FRMSIZE_TYPE_DISCRETE:
268 av_log(ctx, AV_LOG_INFO, " %ux%u",
269 vfse.discrete.width, vfse.discrete.height);
270 break;
271 case V4L2_FRMSIZE_TYPE_CONTINUOUS:
272 case V4L2_FRMSIZE_TYPE_STEPWISE:
273 av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
274 vfse.stepwise.min_width,
275 vfse.stepwise.max_width,
276 vfse.stepwise.step_width,
277 vfse.stepwise.min_height,
278 vfse.stepwise.max_height,
279 vfse.stepwise.step_height);
280 }
281 vfse.index++;
282 }
283 }
284 #endif
285
list_formats(AVFormatContext * ctx,int type)286 static void list_formats(AVFormatContext *ctx, int type)
287 {
288 const struct video_data *s = ctx->priv_data;
289 struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
290
291 while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FMT, &vfd)) {
292 enum AVCodecID codec_id = ff_fmt_v4l2codec(vfd.pixelformat);
293 enum AVPixelFormat pix_fmt = ff_fmt_v4l2ff(vfd.pixelformat, codec_id);
294
295 vfd.index++;
296
297 if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
298 type & V4L_RAWFORMATS) {
299 const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
300 av_log(ctx, AV_LOG_INFO, "Raw : %11s : %20s :",
301 fmt_name ? fmt_name : "Unsupported",
302 vfd.description);
303 } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
304 type & V4L_COMPFORMATS) {
305 const AVCodecDescriptor *desc = avcodec_descriptor_get(codec_id);
306 av_log(ctx, AV_LOG_INFO, "Compressed: %11s : %20s :",
307 desc ? desc->name : "Unsupported",
308 vfd.description);
309 } else {
310 continue;
311 }
312
313 #ifdef V4L2_FMT_FLAG_EMULATED
314 if (vfd.flags & V4L2_FMT_FLAG_EMULATED)
315 av_log(ctx, AV_LOG_INFO, " Emulated :");
316 #endif
317 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
318 list_framesizes(ctx, vfd.pixelformat);
319 #endif
320 av_log(ctx, AV_LOG_INFO, "\n");
321 }
322 }
323
list_standards(AVFormatContext * ctx)324 static void list_standards(AVFormatContext *ctx)
325 {
326 int ret;
327 struct video_data *s = ctx->priv_data;
328 struct v4l2_standard standard;
329
330 if (s->std_id == 0)
331 return;
332
333 for (standard.index = 0; ; standard.index++) {
334 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
335 ret = AVERROR(errno);
336 if (ret == AVERROR(EINVAL)) {
337 break;
338 } else {
339 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
340 return;
341 }
342 }
343 av_log(ctx, AV_LOG_INFO, "%2d, %16"PRIx64", %s\n",
344 standard.index, (uint64_t)standard.id, standard.name);
345 }
346 }
347
mmap_init(AVFormatContext * ctx)348 static int mmap_init(AVFormatContext *ctx)
349 {
350 int i, res;
351 struct video_data *s = ctx->priv_data;
352 struct v4l2_requestbuffers req = {
353 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
354 .count = desired_video_buffers,
355 .memory = V4L2_MEMORY_MMAP
356 };
357
358 if (v4l2_ioctl(s->fd, VIDIOC_REQBUFS, &req) < 0) {
359 res = AVERROR(errno);
360 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS): %s\n", av_err2str(res));
361 return res;
362 }
363
364 if (req.count < 2) {
365 av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
366 return AVERROR(ENOMEM);
367 }
368 s->buffers = req.count;
369 s->buf_start = av_malloc_array(s->buffers, sizeof(void *));
370 if (!s->buf_start) {
371 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
372 return AVERROR(ENOMEM);
373 }
374 s->buf_len = av_malloc_array(s->buffers, sizeof(unsigned int));
375 if (!s->buf_len) {
376 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
377 av_freep(&s->buf_start);
378 return AVERROR(ENOMEM);
379 }
380
381 for (i = 0; i < req.count; i++) {
382 struct v4l2_buffer buf = {
383 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
384 .index = i,
385 .memory = V4L2_MEMORY_MMAP
386 };
387 if (v4l2_ioctl(s->fd, VIDIOC_QUERYBUF, &buf) < 0) {
388 res = AVERROR(errno);
389 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF): %s\n", av_err2str(res));
390 return res;
391 }
392
393 s->buf_len[i] = buf.length;
394 if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
395 av_log(ctx, AV_LOG_ERROR,
396 "buf_len[%d] = %d < expected frame size %d\n",
397 i, s->buf_len[i], s->frame_size);
398 return AVERROR(ENOMEM);
399 }
400 s->buf_start[i] = v4l2_mmap(NULL, buf.length,
401 PROT_READ | PROT_WRITE, MAP_SHARED,
402 s->fd, buf.m.offset);
403
404 if (s->buf_start[i] == MAP_FAILED) {
405 res = AVERROR(errno);
406 av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", av_err2str(res));
407 return res;
408 }
409 }
410
411 return 0;
412 }
413
enqueue_buffer(struct video_data * s,struct v4l2_buffer * buf)414 static int enqueue_buffer(struct video_data *s, struct v4l2_buffer *buf)
415 {
416 int res = 0;
417
418 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, buf) < 0) {
419 res = AVERROR(errno);
420 av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", av_err2str(res));
421 } else {
422 atomic_fetch_add(&s->buffers_queued, 1);
423 }
424
425 return res;
426 }
427
mmap_release_buffer(void * opaque,uint8_t * data)428 static void mmap_release_buffer(void *opaque, uint8_t *data)
429 {
430 struct v4l2_buffer buf = { 0 };
431 struct buff_data *buf_descriptor = opaque;
432 struct video_data *s = buf_descriptor->s;
433
434 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
435 buf.memory = V4L2_MEMORY_MMAP;
436 buf.index = buf_descriptor->index;
437 av_free(buf_descriptor);
438
439 enqueue_buffer(s, &buf);
440 }
441
442 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
av_gettime_monotonic(void)443 static int64_t av_gettime_monotonic(void)
444 {
445 return av_gettime_relative();
446 }
447 #endif
448
init_convert_timestamp(AVFormatContext * ctx,int64_t ts)449 static int init_convert_timestamp(AVFormatContext *ctx, int64_t ts)
450 {
451 struct video_data *s = ctx->priv_data;
452 int64_t now;
453
454 now = av_gettime();
455 if (s->ts_mode == V4L_TS_ABS &&
456 ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE) {
457 av_log(ctx, AV_LOG_INFO, "Detected absolute timestamps\n");
458 s->ts_mode = V4L_TS_CONVERT_READY;
459 return 0;
460 }
461 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
462 if (ctx->streams[0]->avg_frame_rate.num) {
463 now = av_gettime_monotonic();
464 if (s->ts_mode == V4L_TS_MONO2ABS ||
465 (ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE)) {
466 AVRational tb = {AV_TIME_BASE, 1};
467 int64_t period = av_rescale_q(1, tb, ctx->streams[0]->avg_frame_rate);
468 av_log(ctx, AV_LOG_INFO, "Detected monotonic timestamps, converting\n");
469 /* microseconds instead of seconds, MHz instead of Hz */
470 s->timefilter = ff_timefilter_new(1, period, 1.0E-6);
471 if (!s->timefilter)
472 return AVERROR(ENOMEM);
473 s->ts_mode = V4L_TS_CONVERT_READY;
474 return 0;
475 }
476 }
477 #endif
478 av_log(ctx, AV_LOG_ERROR, "Unknown timestamps\n");
479 return AVERROR(EIO);
480 }
481
convert_timestamp(AVFormatContext * ctx,int64_t * ts)482 static int convert_timestamp(AVFormatContext *ctx, int64_t *ts)
483 {
484 struct video_data *s = ctx->priv_data;
485
486 if (s->ts_mode) {
487 int r = init_convert_timestamp(ctx, *ts);
488 if (r < 0)
489 return r;
490 }
491 #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
492 if (s->timefilter) {
493 int64_t nowa = av_gettime();
494 int64_t nowm = av_gettime_monotonic();
495 ff_timefilter_update(s->timefilter, nowa, nowm - s->last_time_m);
496 s->last_time_m = nowm;
497 *ts = ff_timefilter_eval(s->timefilter, *ts - nowm);
498 }
499 #endif
500 return 0;
501 }
502
mmap_read_frame(AVFormatContext * ctx,AVPacket * pkt)503 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
504 {
505 struct video_data *s = ctx->priv_data;
506 struct v4l2_buffer buf = {
507 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
508 .memory = V4L2_MEMORY_MMAP
509 };
510 struct timeval buf_ts;
511 int res;
512
513 pkt->size = 0;
514
515 /* FIXME: Some special treatment might be needed in case of loss of signal... */
516 while ((res = v4l2_ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
517 if (res < 0) {
518 if (errno == EAGAIN)
519 return AVERROR(EAGAIN);
520
521 res = AVERROR(errno);
522 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n",
523 av_err2str(res));
524 return res;
525 }
526
527 buf_ts = buf.timestamp;
528
529 if (buf.index >= s->buffers) {
530 av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
531 return AVERROR(EINVAL);
532 }
533 atomic_fetch_add(&s->buffers_queued, -1);
534 // always keep at least one buffer queued
535 av_assert0(atomic_load(&s->buffers_queued) >= 1);
536
537 #ifdef V4L2_BUF_FLAG_ERROR
538 if (buf.flags & V4L2_BUF_FLAG_ERROR) {
539 av_log(ctx, AV_LOG_WARNING,
540 "Dequeued v4l2 buffer contains corrupted data (%d bytes).\n",
541 buf.bytesused);
542 buf.bytesused = 0;
543 } else
544 #endif
545 {
546 /* CPIA is a compressed format and we don't know the exact number of bytes
547 * used by a frame, so set it here as the driver announces it. */
548 if (ctx->video_codec_id == AV_CODEC_ID_CPIA)
549 s->frame_size = buf.bytesused;
550
551 if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
552 av_log(ctx, AV_LOG_WARNING,
553 "Dequeued v4l2 buffer contains %d bytes, but %d were expected. Flags: 0x%08X.\n",
554 buf.bytesused, s->frame_size, buf.flags);
555 buf.bytesused = 0;
556 }
557 }
558
559 /* Image is at s->buff_start[buf.index] */
560 if (atomic_load(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
561 /* when we start getting low on queued buffers, fall back on copying data */
562 res = av_new_packet(pkt, buf.bytesused);
563 if (res < 0) {
564 av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
565 enqueue_buffer(s, &buf);
566 return res;
567 }
568 memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
569
570 res = enqueue_buffer(s, &buf);
571 if (res) {
572 av_packet_unref(pkt);
573 return res;
574 }
575 } else {
576 struct buff_data *buf_descriptor;
577
578 pkt->data = s->buf_start[buf.index];
579 pkt->size = buf.bytesused;
580
581 buf_descriptor = av_malloc(sizeof(struct buff_data));
582 if (!buf_descriptor) {
583 /* Something went wrong... Since av_malloc() failed, we cannot even
584 * allocate a buffer for memcpying into it
585 */
586 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
587 enqueue_buffer(s, &buf);
588
589 return AVERROR(ENOMEM);
590 }
591 buf_descriptor->index = buf.index;
592 buf_descriptor->s = s;
593
594 pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
595 buf_descriptor, 0);
596 if (!pkt->buf) {
597 av_log(ctx, AV_LOG_ERROR, "Failed to create a buffer\n");
598 enqueue_buffer(s, &buf);
599 av_freep(&buf_descriptor);
600 return AVERROR(ENOMEM);
601 }
602 }
603 pkt->pts = buf_ts.tv_sec * INT64_C(1000000) + buf_ts.tv_usec;
604 convert_timestamp(ctx, &pkt->pts);
605
606 return pkt->size;
607 }
608
mmap_start(AVFormatContext * ctx)609 static int mmap_start(AVFormatContext *ctx)
610 {
611 struct video_data *s = ctx->priv_data;
612 enum v4l2_buf_type type;
613 int i, res;
614
615 for (i = 0; i < s->buffers; i++) {
616 struct v4l2_buffer buf = {
617 .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
618 .index = i,
619 .memory = V4L2_MEMORY_MMAP
620 };
621
622 if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
623 res = AVERROR(errno);
624 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
625 av_err2str(res));
626 return res;
627 }
628 }
629 atomic_store(&s->buffers_queued, s->buffers);
630
631 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
632 if (v4l2_ioctl(s->fd, VIDIOC_STREAMON, &type) < 0) {
633 res = AVERROR(errno);
634 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
635 av_err2str(res));
636 return res;
637 }
638
639 return 0;
640 }
641
mmap_close(struct video_data * s)642 static void mmap_close(struct video_data *s)
643 {
644 enum v4l2_buf_type type;
645 int i;
646
647 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
648 /* We do not check for the result, because we could
649 * not do anything about it anyway...
650 */
651 v4l2_ioctl(s->fd, VIDIOC_STREAMOFF, &type);
652 for (i = 0; i < s->buffers; i++) {
653 v4l2_munmap(s->buf_start[i], s->buf_len[i]);
654 }
655 av_freep(&s->buf_start);
656 av_freep(&s->buf_len);
657 }
658
v4l2_set_parameters(AVFormatContext * ctx)659 static int v4l2_set_parameters(AVFormatContext *ctx)
660 {
661 struct video_data *s = ctx->priv_data;
662 struct v4l2_standard standard = { 0 };
663 struct v4l2_streamparm streamparm = { 0 };
664 struct v4l2_fract *tpf;
665 AVRational framerate_q = { 0 };
666 int i, ret;
667
668 if (s->framerate &&
669 (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
670 av_log(ctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
671 s->framerate);
672 return ret;
673 }
674
675 if (s->standard) {
676 if (s->std_id) {
677 ret = 0;
678 av_log(ctx, AV_LOG_DEBUG, "Setting standard: %s\n", s->standard);
679 /* set tv standard */
680 for (i = 0; ; i++) {
681 standard.index = i;
682 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
683 ret = AVERROR(errno);
684 break;
685 }
686 if (!av_strcasecmp(standard.name, s->standard))
687 break;
688 }
689 if (ret < 0) {
690 av_log(ctx, AV_LOG_ERROR, "Unknown or unsupported standard '%s'\n", s->standard);
691 return ret;
692 }
693
694 if (v4l2_ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
695 ret = AVERROR(errno);
696 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_STD): %s\n", av_err2str(ret));
697 return ret;
698 }
699 } else {
700 av_log(ctx, AV_LOG_WARNING,
701 "This device does not support any standard\n");
702 }
703 }
704
705 /* get standard */
706 if (v4l2_ioctl(s->fd, VIDIOC_G_STD, &s->std_id) == 0) {
707 tpf = &standard.frameperiod;
708 for (i = 0; ; i++) {
709 standard.index = i;
710 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
711 ret = AVERROR(errno);
712 if (ret == AVERROR(EINVAL)
713 #ifdef ENODATA
714 || ret == AVERROR(ENODATA)
715 #endif
716 ) {
717 tpf = &streamparm.parm.capture.timeperframe;
718 break;
719 }
720 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
721 return ret;
722 }
723 if (standard.id == s->std_id) {
724 av_log(ctx, AV_LOG_DEBUG,
725 "Current standard: %s, id: %"PRIx64", frameperiod: %d/%d\n",
726 standard.name, (uint64_t)standard.id, tpf->numerator, tpf->denominator);
727 break;
728 }
729 }
730 } else {
731 tpf = &streamparm.parm.capture.timeperframe;
732 }
733
734 streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
735 if (v4l2_ioctl(s->fd, VIDIOC_G_PARM, &streamparm) < 0) {
736 ret = AVERROR(errno);
737 av_log(ctx, AV_LOG_WARNING, "ioctl(VIDIOC_G_PARM): %s\n", av_err2str(ret));
738 } else if (framerate_q.num && framerate_q.den) {
739 if (streamparm.parm.capture.capability & V4L2_CAP_TIMEPERFRAME) {
740 tpf = &streamparm.parm.capture.timeperframe;
741
742 av_log(ctx, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
743 framerate_q.den, framerate_q.num);
744 tpf->numerator = framerate_q.den;
745 tpf->denominator = framerate_q.num;
746
747 if (v4l2_ioctl(s->fd, VIDIOC_S_PARM, &streamparm) < 0) {
748 ret = AVERROR(errno);
749 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_PARM): %s\n",
750 av_err2str(ret));
751 return ret;
752 }
753
754 if (framerate_q.num != tpf->denominator ||
755 framerate_q.den != tpf->numerator) {
756 av_log(ctx, AV_LOG_INFO,
757 "The driver changed the time per frame from "
758 "%d/%d to %d/%d\n",
759 framerate_q.den, framerate_q.num,
760 tpf->numerator, tpf->denominator);
761 }
762 } else {
763 av_log(ctx, AV_LOG_WARNING,
764 "The driver does not permit changing the time per frame\n");
765 }
766 }
767 if (tpf->denominator > 0 && tpf->numerator > 0) {
768 ctx->streams[0]->avg_frame_rate.num = tpf->denominator;
769 ctx->streams[0]->avg_frame_rate.den = tpf->numerator;
770 ctx->streams[0]->r_frame_rate = ctx->streams[0]->avg_frame_rate;
771 } else
772 av_log(ctx, AV_LOG_WARNING, "Time per frame unknown\n");
773
774 return 0;
775 }
776
device_try_init(AVFormatContext * ctx,enum AVPixelFormat pix_fmt,int * width,int * height,uint32_t * desired_format,enum AVCodecID * codec_id)777 static int device_try_init(AVFormatContext *ctx,
778 enum AVPixelFormat pix_fmt,
779 int *width,
780 int *height,
781 uint32_t *desired_format,
782 enum AVCodecID *codec_id)
783 {
784 int ret, i;
785
786 *desired_format = ff_fmt_ff2v4l(pix_fmt, ctx->video_codec_id);
787
788 if (*desired_format) {
789 ret = device_init(ctx, width, height, *desired_format);
790 if (ret < 0) {
791 *desired_format = 0;
792 if (ret != AVERROR(EINVAL))
793 return ret;
794 }
795 }
796
797 if (!*desired_format) {
798 for (i = 0; ff_fmt_conversion_table[i].codec_id != AV_CODEC_ID_NONE; i++) {
799 if (ctx->video_codec_id == AV_CODEC_ID_NONE ||
800 ff_fmt_conversion_table[i].codec_id == ctx->video_codec_id) {
801 av_log(ctx, AV_LOG_DEBUG, "Trying to set codec:%s pix_fmt:%s\n",
802 avcodec_get_name(ff_fmt_conversion_table[i].codec_id),
803 (char *)av_x_if_null(av_get_pix_fmt_name(ff_fmt_conversion_table[i].ff_fmt), "none"));
804
805 *desired_format = ff_fmt_conversion_table[i].v4l2_fmt;
806 ret = device_init(ctx, width, height, *desired_format);
807 if (ret >= 0)
808 break;
809 else if (ret != AVERROR(EINVAL))
810 return ret;
811 *desired_format = 0;
812 }
813 }
814
815 if (*desired_format == 0) {
816 av_log(ctx, AV_LOG_ERROR, "Cannot find a proper format for "
817 "codec '%s' (id %d), pixel format '%s' (id %d)\n",
818 avcodec_get_name(ctx->video_codec_id), ctx->video_codec_id,
819 (char *)av_x_if_null(av_get_pix_fmt_name(pix_fmt), "none"), pix_fmt);
820 ret = AVERROR(EINVAL);
821 }
822 }
823
824 *codec_id = ff_fmt_v4l2codec(*desired_format);
825 if (*codec_id == AV_CODEC_ID_NONE)
826 av_assert0(ret == AVERROR(EINVAL));
827 return ret;
828 }
829
v4l2_read_probe(const AVProbeData * p)830 static int v4l2_read_probe(const AVProbeData *p)
831 {
832 if (av_strstart(p->filename, "/dev/video", NULL))
833 return AVPROBE_SCORE_MAX - 1;
834 return 0;
835 }
836
v4l2_read_header(AVFormatContext * ctx)837 static int v4l2_read_header(AVFormatContext *ctx)
838 {
839 struct video_data *s = ctx->priv_data;
840 AVStream *st;
841 int res = 0;
842 uint32_t desired_format;
843 enum AVCodecID codec_id = AV_CODEC_ID_NONE;
844 enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
845 struct v4l2_input input = { 0 };
846
847 st = avformat_new_stream(ctx, NULL);
848 if (!st)
849 return AVERROR(ENOMEM);
850
851 #if CONFIG_LIBV4L2
852 /* silence libv4l2 logging. if fopen() fails v4l2_log_file will be NULL
853 and errors will get sent to stderr */
854 if (s->use_libv4l2)
855 v4l2_log_file = fopen("/dev/null", "w");
856 #endif
857
858 s->fd = device_open(ctx, ctx->url);
859 if (s->fd < 0)
860 return s->fd;
861
862 if (s->channel != -1) {
863 /* set video input */
864 av_log(ctx, AV_LOG_DEBUG, "Selecting input_channel: %d\n", s->channel);
865 if (v4l2_ioctl(s->fd, VIDIOC_S_INPUT, &s->channel) < 0) {
866 res = AVERROR(errno);
867 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_INPUT): %s\n", av_err2str(res));
868 goto fail;
869 }
870 } else {
871 /* get current video input */
872 if (v4l2_ioctl(s->fd, VIDIOC_G_INPUT, &s->channel) < 0) {
873 res = AVERROR(errno);
874 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_INPUT): %s\n", av_err2str(res));
875 goto fail;
876 }
877 }
878
879 /* enum input */
880 input.index = s->channel;
881 if (v4l2_ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
882 res = AVERROR(errno);
883 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMINPUT): %s\n", av_err2str(res));
884 goto fail;
885 }
886 s->std_id = input.std;
887 av_log(ctx, AV_LOG_DEBUG, "Current input_channel: %d, input_name: %s, input_std: %"PRIx64"\n",
888 s->channel, input.name, (uint64_t)input.std);
889
890 if (s->list_format) {
891 list_formats(ctx, s->list_format);
892 res = AVERROR_EXIT;
893 goto fail;
894 }
895
896 if (s->list_standard) {
897 list_standards(ctx);
898 res = AVERROR_EXIT;
899 goto fail;
900 }
901
902 avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
903
904 if (s->pixel_format) {
905 const AVCodecDescriptor *desc = avcodec_descriptor_get_by_name(s->pixel_format);
906
907 if (desc)
908 ctx->video_codec_id = desc->id;
909
910 pix_fmt = av_get_pix_fmt(s->pixel_format);
911
912 if (pix_fmt == AV_PIX_FMT_NONE && !desc) {
913 av_log(ctx, AV_LOG_ERROR, "No such input format: %s.\n",
914 s->pixel_format);
915
916 res = AVERROR(EINVAL);
917 goto fail;
918 }
919 }
920
921 if (!s->width && !s->height) {
922 struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
923
924 av_log(ctx, AV_LOG_VERBOSE,
925 "Querying the device for the current frame size\n");
926 if (v4l2_ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
927 res = AVERROR(errno);
928 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
929 av_err2str(res));
930 goto fail;
931 }
932
933 s->width = fmt.fmt.pix.width;
934 s->height = fmt.fmt.pix.height;
935 av_log(ctx, AV_LOG_VERBOSE,
936 "Setting frame size to %dx%d\n", s->width, s->height);
937 }
938
939 res = device_try_init(ctx, pix_fmt, &s->width, &s->height, &desired_format, &codec_id);
940 if (res < 0)
941 goto fail;
942
943 /* If no pixel_format was specified, the codec_id was not known up
944 * until now. Set video_codec_id in the context, as codec_id will
945 * not be available outside this function
946 */
947 if (codec_id != AV_CODEC_ID_NONE && ctx->video_codec_id == AV_CODEC_ID_NONE)
948 ctx->video_codec_id = codec_id;
949
950 if ((res = av_image_check_size(s->width, s->height, 0, ctx)) < 0)
951 goto fail;
952
953 s->pixelformat = desired_format;
954
955 if ((res = v4l2_set_parameters(ctx)) < 0)
956 goto fail;
957
958 st->codecpar->format = ff_fmt_v4l2ff(desired_format, codec_id);
959 if (st->codecpar->format != AV_PIX_FMT_NONE)
960 s->frame_size = av_image_get_buffer_size(st->codecpar->format,
961 s->width, s->height, 1);
962
963 if ((res = mmap_init(ctx)) ||
964 (res = mmap_start(ctx)) < 0)
965 goto fail;
966
967 s->top_field_first = first_field(s);
968
969 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
970 st->codecpar->codec_id = codec_id;
971 if (codec_id == AV_CODEC_ID_RAWVIDEO)
972 st->codecpar->codec_tag =
973 avcodec_pix_fmt_to_codec_tag(st->codecpar->format);
974 else if (codec_id == AV_CODEC_ID_H264) {
975 avpriv_stream_set_need_parsing(st, AVSTREAM_PARSE_FULL_ONCE);
976 }
977 if (desired_format == V4L2_PIX_FMT_YVU420)
978 st->codecpar->codec_tag = MKTAG('Y', 'V', '1', '2');
979 else if (desired_format == V4L2_PIX_FMT_YVU410)
980 st->codecpar->codec_tag = MKTAG('Y', 'V', 'U', '9');
981 st->codecpar->width = s->width;
982 st->codecpar->height = s->height;
983 if (st->avg_frame_rate.den)
984 st->codecpar->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
985
986 return 0;
987
988 fail:
989 v4l2_close(s->fd);
990 return res;
991 }
992
v4l2_read_packet(AVFormatContext * ctx,AVPacket * pkt)993 static int v4l2_read_packet(AVFormatContext *ctx, AVPacket *pkt)
994 {
995 int res;
996
997 if ((res = mmap_read_frame(ctx, pkt)) < 0) {
998 return res;
999 }
1000
1001 return pkt->size;
1002 }
1003
v4l2_read_close(AVFormatContext * ctx)1004 static int v4l2_read_close(AVFormatContext *ctx)
1005 {
1006 struct video_data *s = ctx->priv_data;
1007
1008 if (atomic_load(&s->buffers_queued) != s->buffers)
1009 av_log(ctx, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
1010 "close.\n");
1011
1012 mmap_close(s);
1013
1014 v4l2_close(s->fd);
1015 return 0;
1016 }
1017
v4l2_is_v4l_dev(const char * name)1018 static int v4l2_is_v4l_dev(const char *name)
1019 {
1020 return !strncmp(name, "video", 5) ||
1021 !strncmp(name, "radio", 5) ||
1022 !strncmp(name, "vbi", 3) ||
1023 !strncmp(name, "v4l-subdev", 10);
1024 }
1025
v4l2_get_device_list(AVFormatContext * ctx,AVDeviceInfoList * device_list)1026 static int v4l2_get_device_list(AVFormatContext *ctx, AVDeviceInfoList *device_list)
1027 {
1028 struct video_data *s = ctx->priv_data;
1029 DIR *dir;
1030 struct dirent *entry;
1031 int ret = 0;
1032
1033 if (!device_list)
1034 return AVERROR(EINVAL);
1035
1036 dir = opendir("/dev");
1037 if (!dir) {
1038 ret = AVERROR(errno);
1039 av_log(ctx, AV_LOG_ERROR, "Couldn't open the directory: %s\n", av_err2str(ret));
1040 return ret;
1041 }
1042 while ((entry = readdir(dir))) {
1043 AVDeviceInfo *device = NULL;
1044 struct v4l2_capability cap;
1045 int fd = -1, size;
1046 char device_name[256];
1047
1048 if (!v4l2_is_v4l_dev(entry->d_name))
1049 continue;
1050
1051 size = snprintf(device_name, sizeof(device_name), "/dev/%s", entry->d_name);
1052 if (size >= sizeof(device_name)) {
1053 av_log(ctx, AV_LOG_ERROR, "Device name too long.\n");
1054 ret = AVERROR(ENOSYS);
1055 break;
1056 }
1057
1058 if ((fd = device_open(ctx, device_name)) < 0)
1059 continue;
1060
1061 if (v4l2_ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0) {
1062 ret = AVERROR(errno);
1063 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n", av_err2str(ret));
1064 goto fail;
1065 }
1066
1067 device = av_mallocz(sizeof(AVDeviceInfo));
1068 if (!device) {
1069 ret = AVERROR(ENOMEM);
1070 goto fail;
1071 }
1072 device->device_name = av_strdup(device_name);
1073 device->device_description = av_strdup(cap.card);
1074 if (!device->device_name || !device->device_description) {
1075 ret = AVERROR(ENOMEM);
1076 goto fail;
1077 }
1078
1079 if ((ret = av_dynarray_add_nofree(&device_list->devices,
1080 &device_list->nb_devices, device)) < 0)
1081 goto fail;
1082
1083 v4l2_close(fd);
1084 continue;
1085
1086 fail:
1087 if (device) {
1088 av_freep(&device->device_name);
1089 av_freep(&device->device_description);
1090 av_freep(&device);
1091 }
1092 v4l2_close(fd);
1093 break;
1094 }
1095 closedir(dir);
1096 return ret;
1097 }
1098
1099 #define OFFSET(x) offsetof(struct video_data, x)
1100 #define DEC AV_OPT_FLAG_DECODING_PARAM
1101
1102 static const AVOption options[] = {
1103 { "standard", "set TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
1104 { "channel", "set TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.i64 = -1 }, -1, INT_MAX, DEC },
1105 { "video_size", "set frame size", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC },
1106 { "pixel_format", "set preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1107 { "input_format", "set preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1108 { "framerate", "set frame rate", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
1109
1110 { "list_formats", "list available formats and exit", OFFSET(list_format), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, DEC, "list_formats" },
1111 { "all", "show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_ALLFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1112 { "raw", "show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_RAWFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1113 { "compressed", "show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.i64 = V4L_COMPFORMATS }, 0, INT_MAX, DEC, "list_formats" },
1114
1115 { "list_standards", "list supported standards and exit", OFFSET(list_standard), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 1, DEC, "list_standards" },
1116 { "all", "show all supported standards", OFFSET(list_standard), AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, DEC, "list_standards" },
1117
1118 { "timestamps", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1119 { "ts", "set type of timestamps for grabbed frames", OFFSET(ts_mode), AV_OPT_TYPE_INT, {.i64 = 0 }, 0, 2, DEC, "timestamps" },
1120 { "default", "use timestamps from the kernel", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_DEFAULT }, 0, 2, DEC, "timestamps" },
1121 { "abs", "use absolute timestamps (wall clock)", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_ABS }, 0, 2, DEC, "timestamps" },
1122 { "mono2abs", "force conversion from monotonic to absolute timestamps", OFFSET(ts_mode), AV_OPT_TYPE_CONST, {.i64 = V4L_TS_MONO2ABS }, 0, 2, DEC, "timestamps" },
1123 { "use_libv4l2", "use libv4l2 (v4l-utils) conversion functions", OFFSET(use_libv4l2), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
1124 { NULL },
1125 };
1126
1127 static const AVClass v4l2_class = {
1128 .class_name = "V4L2 indev",
1129 .item_name = av_default_item_name,
1130 .option = options,
1131 .version = LIBAVUTIL_VERSION_INT,
1132 .category = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
1133 };
1134
1135 const AVInputFormat ff_v4l2_demuxer = {
1136 .name = "video4linux2,v4l2",
1137 .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
1138 .priv_data_size = sizeof(struct video_data),
1139 .read_probe = v4l2_read_probe,
1140 .read_header = v4l2_read_header,
1141 .read_packet = v4l2_read_packet,
1142 .read_close = v4l2_read_close,
1143 .get_device_list = v4l2_get_device_list,
1144 .flags = AVFMT_NOFILE,
1145 .priv_class = &v4l2_class,
1146 };
1147