v4l2.c
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1 /*
2  * Video4Linux2 grab interface
3  * Copyright (c) 2000,2001 Fabrice Bellard
4  * Copyright (c) 2006 Luca Abeni
5  *
6  * Part of this file is based on the V4L2 video capture example
7  * (http://v4l2spec.bytesex.org/v4l2spec/capture.c)
8  *
9  * Thanks to Michael Niedermayer for providing the mapping between
10  * V4L2_PIX_FMT_* and PIX_FMT_*
11  *
12  *
13  * This file is part of Libav.
14  *
15  * Libav is free software; you can redistribute it and/or
16  * modify it under the terms of the GNU Lesser General Public
17  * License as published by the Free Software Foundation; either
18  * version 2.1 of the License, or (at your option) any later version.
19  *
20  * Libav is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
23  * Lesser General Public License for more details.
24  *
25  * You should have received a copy of the GNU Lesser General Public
26  * License along with Libav; if not, write to the Free Software
27  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
28  */
29 
30 #undef __STRICT_ANSI__ //workaround due to broken kernel headers
31 #include "config.h"
32 #include "libavformat/avformat.h"
33 #include "libavformat/internal.h"
34 #include <unistd.h>
35 #include <fcntl.h>
36 #include <sys/ioctl.h>
37 #include <sys/mman.h>
38 #include <sys/time.h>
39 #include <poll.h>
40 #if HAVE_SYS_VIDEOIO_H
41 #include <sys/videoio.h>
42 #else
43 #include <linux/videodev2.h>
44 #endif
45 #include <time.h>
46 #include "libavutil/imgutils.h"
47 #include "libavutil/log.h"
48 #include "libavutil/opt.h"
49 #include "libavutil/parseutils.h"
50 #include "libavutil/pixdesc.h"
51 #include "libavutil/avstring.h"
52 #include "libavutil/mathematics.h"
53 
54 static const int desired_video_buffers = 256;
55 
56 #define V4L_ALLFORMATS 3
57 #define V4L_RAWFORMATS 1
58 #define V4L_COMPFORMATS 2
59 
60 struct video_data {
61  AVClass *class;
62  int fd;
63  int frame_format; /* V4L2_PIX_FMT_* */
64  int width, height;
66  int timeout;
69 
70  int buffers;
71  void **buf_start;
72  unsigned int *buf_len;
73  char *standard;
74  int channel;
75  char *video_size;
77  char *pixel_format;
79  char *framerate;
80 };
81 
82 struct buff_data {
83  int index;
84  int fd;
85 };
86 
87 struct fmt_map {
90  uint32_t v4l2_fmt;
91 };
92 
93 static struct fmt_map fmt_conversion_table[] = {
94  //ff_fmt codec_id v4l2_fmt
95  { PIX_FMT_YUV420P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420 },
96  { PIX_FMT_YUV422P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV422P },
97  { PIX_FMT_YUYV422, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUYV },
98  { PIX_FMT_UYVY422, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_UYVY },
99  { PIX_FMT_YUV411P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV411P },
100  { PIX_FMT_YUV410P, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV410 },
101  { PIX_FMT_RGB555, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB555 },
102  { PIX_FMT_RGB565, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB565 },
103  { PIX_FMT_BGR24, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR24 },
104  { PIX_FMT_RGB24, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB24 },
105  { PIX_FMT_BGRA, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR32 },
106  { PIX_FMT_GRAY8, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_GREY },
107  { PIX_FMT_NV12, CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12 },
108  { PIX_FMT_NONE, CODEC_ID_MJPEG, V4L2_PIX_FMT_MJPEG },
109  { PIX_FMT_NONE, CODEC_ID_MJPEG, V4L2_PIX_FMT_JPEG },
110 };
111 
112 static int device_open(AVFormatContext *ctx)
113 {
114  struct v4l2_capability cap;
115  int fd;
116  int res, err;
117  int flags = O_RDWR;
118 
119  if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
120  flags |= O_NONBLOCK;
121  }
122 
123  fd = open(ctx->filename, flags, 0);
124  if (fd < 0) {
125  err = errno;
126 
127  av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
128  ctx->filename, strerror(err));
129 
130  return AVERROR(err);
131  }
132 
133  res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
134  if (res < 0) {
135  err = errno;
136  av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
137  strerror(err));
138 
139  goto fail;
140  }
141 
142  av_log(ctx, AV_LOG_VERBOSE, "[%d]Capabilities: %x\n",
143  fd, cap.capabilities);
144 
145  if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
146  av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
147  err = ENODEV;
148 
149  goto fail;
150  }
151 
152  if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
153  av_log(ctx, AV_LOG_ERROR,
154  "The device does not support the streaming I/O method.\n");
155  err = ENOSYS;
156 
157  goto fail;
158  }
159 
160  return fd;
161 
162 fail:
163  close(fd);
164  return AVERROR(err);
165 }
166 
167 static int device_init(AVFormatContext *ctx, int *width, int *height,
168  uint32_t pix_fmt)
169 {
170  struct video_data *s = ctx->priv_data;
171  int fd = s->fd;
172  struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
173  struct v4l2_pix_format *pix = &fmt.fmt.pix;
174 
175  int res;
176 
177  pix->width = *width;
178  pix->height = *height;
179  pix->pixelformat = pix_fmt;
180  pix->field = V4L2_FIELD_ANY;
181 
182  res = ioctl(fd, VIDIOC_S_FMT, &fmt);
183 
184  if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
185  av_log(ctx, AV_LOG_INFO,
186  "The V4L2 driver changed the video from %dx%d to %dx%d\n",
187  *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
188  *width = fmt.fmt.pix.width;
189  *height = fmt.fmt.pix.height;
190  }
191 
192  if (pix_fmt != fmt.fmt.pix.pixelformat) {
193  av_log(ctx, AV_LOG_DEBUG,
194  "The V4L2 driver changed the pixel format "
195  "from 0x%08X to 0x%08X\n",
196  pix_fmt, fmt.fmt.pix.pixelformat);
197  res = -1;
198  }
199 
200  if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
201  av_log(ctx, AV_LOG_DEBUG, "The V4L2 driver using the interlaced mode");
202  s->interlaced = 1;
203  }
204 
205  return res;
206 }
207 
208 static int first_field(int fd)
209 {
210  int res;
211  v4l2_std_id std;
212 
213  res = ioctl(fd, VIDIOC_G_STD, &std);
214  if (res < 0) {
215  return 0;
216  }
217  if (std & V4L2_STD_NTSC) {
218  return 0;
219  }
220 
221  return 1;
222 }
223 
224 static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt, enum CodecID codec_id)
225 {
226  int i;
227 
228  for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
229  if ((codec_id == CODEC_ID_NONE ||
230  fmt_conversion_table[i].codec_id == codec_id) &&
231  (pix_fmt == PIX_FMT_NONE ||
232  fmt_conversion_table[i].ff_fmt == pix_fmt)) {
233  return fmt_conversion_table[i].v4l2_fmt;
234  }
235  }
236 
237  return 0;
238 }
239 
240 static enum PixelFormat fmt_v4l2ff(uint32_t v4l2_fmt, enum CodecID codec_id)
241 {
242  int i;
243 
244  for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
245  if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt &&
246  fmt_conversion_table[i].codec_id == codec_id) {
247  return fmt_conversion_table[i].ff_fmt;
248  }
249  }
250 
251  return PIX_FMT_NONE;
252 }
253 
254 static enum CodecID fmt_v4l2codec(uint32_t v4l2_fmt)
255 {
256  int i;
257 
258  for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
259  if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt) {
260  return fmt_conversion_table[i].codec_id;
261  }
262  }
263 
264  return CODEC_ID_NONE;
265 }
266 
267 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
268 static void list_framesizes(AVFormatContext *ctx, int fd, uint32_t pixelformat)
269 {
270  struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
271 
272  while(!ioctl(fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
273  switch (vfse.type) {
274  case V4L2_FRMSIZE_TYPE_DISCRETE:
275  av_log(ctx, AV_LOG_INFO, " %ux%u",
276  vfse.discrete.width, vfse.discrete.height);
277  break;
278  case V4L2_FRMSIZE_TYPE_CONTINUOUS:
279  case V4L2_FRMSIZE_TYPE_STEPWISE:
280  av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
281  vfse.stepwise.min_width,
282  vfse.stepwise.max_width,
283  vfse.stepwise.step_width,
284  vfse.stepwise.min_height,
285  vfse.stepwise.max_height,
286  vfse.stepwise.step_height);
287  }
288  vfse.index++;
289  }
290 }
291 #endif
292 
293 static void list_formats(AVFormatContext *ctx, int fd, int type)
294 {
295  struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
296 
297  while(!ioctl(fd, VIDIOC_ENUM_FMT, &vfd)) {
298  enum CodecID codec_id = fmt_v4l2codec(vfd.pixelformat);
299  enum PixelFormat pix_fmt = fmt_v4l2ff(vfd.pixelformat, codec_id);
300 
301  vfd.index++;
302 
303  if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
304  type & V4L_RAWFORMATS) {
305  const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
306  av_log(ctx, AV_LOG_INFO, "R : %9s : %20s :",
307  fmt_name ? fmt_name : "Unsupported",
308  vfd.description);
309  } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
310  type & V4L_COMPFORMATS) {
311  AVCodec *codec = avcodec_find_encoder(codec_id);
312  av_log(ctx, AV_LOG_INFO, "C : %9s : %20s :",
313  codec ? codec->name : "Unsupported",
314  vfd.description);
315  } else {
316  continue;
317  }
318 
319 #ifdef V4L2_FMT_FLAG_EMULATED
320  if (vfd.flags & V4L2_FMT_FLAG_EMULATED) {
321  av_log(ctx, AV_LOG_WARNING, "%s", "Emulated");
322  continue;
323  }
324 #endif
325 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
326  list_framesizes(ctx, fd, vfd.pixelformat);
327 #endif
328  av_log(ctx, AV_LOG_INFO, "\n");
329  }
330 }
331 
332 static int mmap_init(AVFormatContext *ctx)
333 {
334  int i, res;
335  struct video_data *s = ctx->priv_data;
336  struct v4l2_requestbuffers req = {
337  .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
338  .count = desired_video_buffers,
339  .memory = V4L2_MEMORY_MMAP
340  };
341 
342  res = ioctl(s->fd, VIDIOC_REQBUFS, &req);
343  if (res < 0) {
344  if (errno == EINVAL) {
345  av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
346  } else {
347  av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
348  }
349 
350  return AVERROR(errno);
351  }
352 
353  if (req.count < 2) {
354  av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
355 
356  return AVERROR(ENOMEM);
357  }
358  s->buffers = req.count;
359  s->buf_start = av_malloc(sizeof(void *) * s->buffers);
360  if (s->buf_start == NULL) {
361  av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
362 
363  return AVERROR(ENOMEM);
364  }
365  s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
366  if (s->buf_len == NULL) {
367  av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
368  av_free(s->buf_start);
369 
370  return AVERROR(ENOMEM);
371  }
372 
373  for (i = 0; i < req.count; i++) {
374  struct v4l2_buffer buf = {
375  .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
376  .index = i,
377  .memory = V4L2_MEMORY_MMAP
378  };
379 
380  res = ioctl(s->fd, VIDIOC_QUERYBUF, &buf);
381  if (res < 0) {
382  av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
383 
384  return AVERROR(errno);
385  }
386 
387  s->buf_len[i] = buf.length;
388  if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
389  av_log(ctx, AV_LOG_ERROR,
390  "Buffer len [%d] = %d != %d\n",
391  i, s->buf_len[i], s->frame_size);
392 
393  return -1;
394  }
395  s->buf_start[i] = mmap(NULL, buf.length,
396  PROT_READ | PROT_WRITE, MAP_SHARED,
397  s->fd, buf.m.offset);
398 
399  if (s->buf_start[i] == MAP_FAILED) {
400  av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
401 
402  return AVERROR(errno);
403  }
404  }
405 
406  return 0;
407 }
408 
409 static void mmap_release_buffer(AVPacket *pkt)
410 {
411  struct v4l2_buffer buf = { 0 };
412  int res, fd;
413  struct buff_data *buf_descriptor = pkt->priv;
414 
415  if (pkt->data == NULL)
416  return;
417 
418  buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
419  buf.memory = V4L2_MEMORY_MMAP;
420  buf.index = buf_descriptor->index;
421  fd = buf_descriptor->fd;
422  av_free(buf_descriptor);
423 
424  res = ioctl(fd, VIDIOC_QBUF, &buf);
425  if (res < 0)
426  av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
427  strerror(errno));
428 
429  pkt->data = NULL;
430  pkt->size = 0;
431 }
432 
434 {
435  struct video_data *s = ctx->priv_data;
436  struct v4l2_buffer buf = {
437  .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
438  .memory = V4L2_MEMORY_MMAP
439  };
440  struct buff_data *buf_descriptor;
441  struct pollfd p = { .fd = s->fd, .events = POLLIN };
442  int res;
443 
444  res = poll(&p, 1, s->timeout);
445  if (res < 0)
446  return AVERROR(errno);
447 
448  if (!(p.revents & (POLLIN | POLLERR | POLLHUP)))
449  return AVERROR(EAGAIN);
450 
451  /* FIXME: Some special treatment might be needed in case of loss of signal... */
452  while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
453  if (res < 0) {
454  if (errno == EAGAIN) {
455  pkt->size = 0;
456 
457  return AVERROR(EAGAIN);
458  }
459  av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n",
460  strerror(errno));
461 
462  return AVERROR(errno);
463  }
464  assert (buf.index < s->buffers);
465  if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
466  av_log(ctx, AV_LOG_ERROR,
467  "The v4l2 frame is %d bytes, but %d bytes are expected\n",
468  buf.bytesused, s->frame_size);
469 
470  return AVERROR_INVALIDDATA;
471  }
472 
473  /* Image is at s->buff_start[buf.index] */
474  pkt->data= s->buf_start[buf.index];
475  pkt->size = buf.bytesused;
476  pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
478  buf_descriptor = av_malloc(sizeof(struct buff_data));
479  if (buf_descriptor == NULL) {
480  /* Something went wrong... Since av_malloc() failed, we cannot even
481  * allocate a buffer for memcopying into it
482  */
483  av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
484  res = ioctl(s->fd, VIDIOC_QBUF, &buf);
485 
486  return AVERROR(ENOMEM);
487  }
488  buf_descriptor->fd = s->fd;
489  buf_descriptor->index = buf.index;
490  pkt->priv = buf_descriptor;
491 
492  return s->buf_len[buf.index];
493 }
494 
495 static int mmap_start(AVFormatContext *ctx)
496 {
497  struct video_data *s = ctx->priv_data;
498  enum v4l2_buf_type type;
499  int i, res;
500 
501  for (i = 0; i < s->buffers; i++) {
502  struct v4l2_buffer buf = {
503  .type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
504  .index = i,
505  .memory = V4L2_MEMORY_MMAP
506  };
507 
508  res = ioctl(s->fd, VIDIOC_QBUF, &buf);
509  if (res < 0) {
510  av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
511  strerror(errno));
512 
513  return AVERROR(errno);
514  }
515  }
516 
517  type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
518  res = ioctl(s->fd, VIDIOC_STREAMON, &type);
519  if (res < 0) {
520  av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
521  strerror(errno));
522 
523  return AVERROR(errno);
524  }
525 
526  return 0;
527 }
528 
529 static void mmap_close(struct video_data *s)
530 {
531  enum v4l2_buf_type type;
532  int i;
533 
534  type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
535  /* We do not check for the result, because we could
536  * not do anything about it anyway...
537  */
538  ioctl(s->fd, VIDIOC_STREAMOFF, &type);
539  for (i = 0; i < s->buffers; i++) {
540  munmap(s->buf_start[i], s->buf_len[i]);
541  }
542  av_free(s->buf_start);
543  av_free(s->buf_len);
544 }
545 
547 {
548  struct video_data *s = s1->priv_data;
549  struct v4l2_input input = { 0 };
550  struct v4l2_standard standard = { 0 };
551  struct v4l2_streamparm streamparm = { 0 };
552  struct v4l2_fract *tpf = &streamparm.parm.capture.timeperframe;
553  AVRational framerate_q = { 0 };
554  int i, ret;
555 
556  streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
557 
558  if (s->framerate &&
559  (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
560  av_log(s1, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
561  s->framerate);
562  return ret;
563  }
564 
565  /* set tv video input */
566  input.index = s->channel;
567  if (ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
568  av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
569  return AVERROR(EIO);
570  }
571 
572  av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
573  s->channel, input.name);
574  if (ioctl(s->fd, VIDIOC_S_INPUT, &input.index) < 0) {
575  av_log(s1, AV_LOG_ERROR,
576  "The V4L2 driver ioctl set input(%d) failed\n",
577  s->channel);
578  return AVERROR(EIO);
579  }
580 
581  if (s->standard) {
582  av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
583  s->standard);
584  /* set tv standard */
585  for(i=0;;i++) {
586  standard.index = i;
587  if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
588  av_log(s1, AV_LOG_ERROR,
589  "The V4L2 driver ioctl set standard(%s) failed\n",
590  s->standard);
591  return AVERROR(EIO);
592  }
593 
594  if (!av_strcasecmp(standard.name, s->standard)) {
595  break;
596  }
597  }
598 
599  av_log(s1, AV_LOG_DEBUG,
600  "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
601  s->standard, (uint64_t)standard.id);
602  if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
603  av_log(s1, AV_LOG_ERROR,
604  "The V4L2 driver ioctl set standard(%s) failed\n",
605  s->standard);
606  return AVERROR(EIO);
607  }
608  }
609 
610  if (framerate_q.num && framerate_q.den) {
611  av_log(s1, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
612  framerate_q.den, framerate_q.num);
613  tpf->numerator = framerate_q.den;
614  tpf->denominator = framerate_q.num;
615 
616  if (ioctl(s->fd, VIDIOC_S_PARM, &streamparm) != 0) {
617  av_log(s1, AV_LOG_ERROR,
618  "ioctl set time per frame(%d/%d) failed\n",
619  framerate_q.den, framerate_q.num);
620  return AVERROR(EIO);
621  }
622 
623  if (framerate_q.num != tpf->denominator ||
624  framerate_q.den != tpf->numerator) {
625  av_log(s1, AV_LOG_INFO,
626  "The driver changed the time per frame from "
627  "%d/%d to %d/%d\n",
628  framerate_q.den, framerate_q.num,
629  tpf->numerator, tpf->denominator);
630  }
631  } else {
632  if (ioctl(s->fd, VIDIOC_G_PARM, &streamparm) != 0) {
633  av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_PARM): %s\n",
634  strerror(errno));
635  return AVERROR(errno);
636  }
637  }
638  s1->streams[0]->codec->time_base.den = tpf->denominator;
639  s1->streams[0]->codec->time_base.num = tpf->numerator;
640 
641  s->timeout = 100 +
642  av_rescale_q(1, s1->streams[0]->codec->time_base,
643  (AVRational){1, 1000});
644 
645  return 0;
646 }
647 
649  enum PixelFormat pix_fmt,
650  int *width,
651  int *height,
652  enum CodecID *codec_id)
653 {
654  uint32_t desired_format = fmt_ff2v4l(pix_fmt, s1->video_codec_id);
655 
656  if (desired_format == 0 ||
657  device_init(s1, width, height, desired_format) < 0) {
658  int i;
659 
660  desired_format = 0;
661  for (i = 0; i<FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
662  if (s1->video_codec_id == CODEC_ID_NONE ||
663  fmt_conversion_table[i].codec_id == s1->video_codec_id) {
664  desired_format = fmt_conversion_table[i].v4l2_fmt;
665  if (device_init(s1, width, height, desired_format) >= 0) {
666  break;
667  }
668  desired_format = 0;
669  }
670  }
671  }
672 
673  if (desired_format != 0) {
674  *codec_id = fmt_v4l2codec(desired_format);
675  assert(*codec_id != CODEC_ID_NONE);
676  }
677 
678  return desired_format;
679 }
680 
682 {
683  struct video_data *s = s1->priv_data;
684  AVStream *st;
685  int res = 0;
686  uint32_t desired_format;
687  enum CodecID codec_id;
689 
690  st = avformat_new_stream(s1, NULL);
691  if (!st) {
692  res = AVERROR(ENOMEM);
693  goto out;
694  }
695 
696  s->fd = device_open(s1);
697  if (s->fd < 0) {
698  res = s->fd;
699  goto out;
700  }
701 
702  if (s->list_format) {
703  list_formats(s1, s->fd, s->list_format);
704  res = AVERROR_EXIT;
705  goto out;
706  }
707 
708  avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
709 
710  if (s->video_size &&
711  (res = av_parse_video_size(&s->width, &s->height, s->video_size)) < 0) {
712  av_log(s1, AV_LOG_ERROR, "Could not parse video size '%s'.\n",
713  s->video_size);
714  goto out;
715  }
716 
717  if (s->pixel_format) {
719 
720  if (codec)
721  s1->video_codec_id = codec->id;
722 
723  pix_fmt = av_get_pix_fmt(s->pixel_format);
724 
725  if (pix_fmt == PIX_FMT_NONE && !codec) {
726  av_log(s1, AV_LOG_ERROR, "No such input format: %s.\n",
727  s->pixel_format);
728 
729  res = AVERROR(EINVAL);
730  goto out;
731  }
732  }
733 
734  if (!s->width && !s->height) {
735  struct v4l2_format fmt;
736 
738  "Querying the device for the current frame size\n");
739  fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
740  if (ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
741  av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
742  strerror(errno));
743  res = AVERROR(errno);
744  goto out;
745  }
746 
747  s->width = fmt.fmt.pix.width;
748  s->height = fmt.fmt.pix.height;
750  "Setting frame size to %dx%d\n", s->width, s->height);
751  }
752 
753  desired_format = device_try_init(s1, pix_fmt, &s->width, &s->height,
754  &codec_id);
755  if (desired_format == 0) {
756  av_log(s1, AV_LOG_ERROR, "Cannot find a proper format for "
757  "codec_id %d, pix_fmt %d.\n", s1->video_codec_id, pix_fmt);
758  close(s->fd);
759 
760  res = AVERROR(EIO);
761  goto out;
762  }
763 
764  if ((res = av_image_check_size(s->width, s->height, 0, s1) < 0))
765  goto out;
766 
767  s->frame_format = desired_format;
768 
769  if ((res = v4l2_set_parameters(s1, ap) < 0))
770  goto out;
771 
772  st->codec->pix_fmt = fmt_v4l2ff(desired_format, codec_id);
773  s->frame_size =
775 
776  if ((res = mmap_init(s1)) ||
777  (res = mmap_start(s1)) < 0) {
778  close(s->fd);
779  goto out;
780  }
781 
782  s->top_field_first = first_field(s->fd);
783 
785  st->codec->codec_id = codec_id;
786  if (codec_id == CODEC_ID_RAWVIDEO)
787  st->codec->codec_tag =
789  st->codec->width = s->width;
790  st->codec->height = s->height;
791  st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
792 
793 out:
794  return res;
795 }
796 
798 {
799  struct video_data *s = s1->priv_data;
800  AVFrame *frame = s1->streams[0]->codec->coded_frame;
801  int res;
802 
803  av_init_packet(pkt);
804  if ((res = mmap_read_frame(s1, pkt)) < 0) {
805  return res;
806  }
807 
808  if (frame && s->interlaced) {
809  frame->interlaced_frame = 1;
810  frame->top_field_first = s->top_field_first;
811  }
812 
813  return pkt->size;
814 }
815 
817 {
818  struct video_data *s = s1->priv_data;
819 
820  mmap_close(s);
821 
822  close(s->fd);
823  return 0;
824 }
825 
826 #define OFFSET(x) offsetof(struct video_data, x)
827 #define DEC AV_OPT_FLAG_DECODING_PARAM
828 static const AVOption options[] = {
829  { "standard", "TV standard, used only by analog frame grabber", OFFSET(standard), AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0, DEC },
830  { "channel", "TV channel, used only by frame grabber", OFFSET(channel), AV_OPT_TYPE_INT, {.dbl = 0 }, 0, INT_MAX, DEC },
831  { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
832  { "pixel_format", "Preferred pixel format", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
833  { "input_format", "Preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
834  { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
835  { "list_formats", "List available formats and exit", OFFSET(list_format), AV_OPT_TYPE_INT, {.dbl = 0 }, 0, INT_MAX, DEC, "list_formats" },
836  { "all", "Show all available formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.dbl = V4L_ALLFORMATS }, 0, INT_MAX, DEC, "list_formats" },
837  { "raw", "Show only non-compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.dbl = V4L_RAWFORMATS }, 0, INT_MAX, DEC, "list_formats" },
838  { "compressed", "Show only compressed formats", OFFSET(list_format), AV_OPT_TYPE_CONST, {.dbl = V4L_COMPFORMATS }, 0, INT_MAX, DEC, "list_formats" },
839  { NULL },
840 };
841 
842 static const AVClass v4l2_class = {
843  .class_name = "V4L2 indev",
844  .item_name = av_default_item_name,
845  .option = options,
846  .version = LIBAVUTIL_VERSION_INT,
847 };
848 
850  .name = "video4linux2",
851  .long_name = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
852  .priv_data_size = sizeof(struct video_data),
853  .read_header = v4l2_read_header,
854  .read_packet = v4l2_read_packet,
855  .read_close = v4l2_read_close,
856  .flags = AVFMT_NOFILE,
857  .priv_class = &v4l2_class,
858 };