Define device_try_init() as static in libavdevice/v4l2.c.
[libav.git] / libavdevice / v4l2.c
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 FFmpeg.
14 *
15 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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 <unistd.h>
34 #include <fcntl.h>
35 #include <sys/ioctl.h>
36 #include <sys/mman.h>
37 #include <sys/time.h>
38 #if HAVE_SYS_VIDEOIO_H
39 #include <sys/videoio.h>
40 #else
41 #include <asm/types.h>
42 #include <linux/videodev2.h>
43 #endif
44 #include <time.h>
45 #include <strings.h>
46
47 static const int desired_video_buffers = 256;
48
49 enum io_method {
50 io_read,
51 io_mmap,
52 io_userptr
53 };
54
55 struct video_data {
56 int fd;
57 int frame_format; /* V4L2_PIX_FMT_* */
58 enum io_method io_method;
59 int width, height;
60 int frame_size;
61 int top_field_first;
62
63 int buffers;
64 void **buf_start;
65 unsigned int *buf_len;
66 };
67
68 struct buff_data {
69 int index;
70 int fd;
71 };
72
73 struct fmt_map {
74 enum PixelFormat ff_fmt;
75 enum CodecID codec_id;
76 uint32_t v4l2_fmt;
77 };
78
79 static struct fmt_map fmt_conversion_table[] = {
80 {
81 .ff_fmt = PIX_FMT_YUV420P,
82 .codec_id = CODEC_ID_RAWVIDEO,
83 .v4l2_fmt = V4L2_PIX_FMT_YUV420,
84 },
85 {
86 .ff_fmt = PIX_FMT_YUV422P,
87 .codec_id = CODEC_ID_RAWVIDEO,
88 .v4l2_fmt = V4L2_PIX_FMT_YUV422P,
89 },
90 {
91 .ff_fmt = PIX_FMT_YUYV422,
92 .codec_id = CODEC_ID_RAWVIDEO,
93 .v4l2_fmt = V4L2_PIX_FMT_YUYV,
94 },
95 {
96 .ff_fmt = PIX_FMT_UYVY422,
97 .codec_id = CODEC_ID_RAWVIDEO,
98 .v4l2_fmt = V4L2_PIX_FMT_UYVY,
99 },
100 {
101 .ff_fmt = PIX_FMT_YUV411P,
102 .codec_id = CODEC_ID_RAWVIDEO,
103 .v4l2_fmt = V4L2_PIX_FMT_YUV411P,
104 },
105 {
106 .ff_fmt = PIX_FMT_YUV410P,
107 .codec_id = CODEC_ID_RAWVIDEO,
108 .v4l2_fmt = V4L2_PIX_FMT_YUV410,
109 },
110 {
111 .ff_fmt = PIX_FMT_RGB555,
112 .codec_id = CODEC_ID_RAWVIDEO,
113 .v4l2_fmt = V4L2_PIX_FMT_RGB555,
114 },
115 {
116 .ff_fmt = PIX_FMT_RGB565,
117 .codec_id = CODEC_ID_RAWVIDEO,
118 .v4l2_fmt = V4L2_PIX_FMT_RGB565,
119 },
120 {
121 .ff_fmt = PIX_FMT_BGR24,
122 .codec_id = CODEC_ID_RAWVIDEO,
123 .v4l2_fmt = V4L2_PIX_FMT_BGR24,
124 },
125 {
126 .ff_fmt = PIX_FMT_RGB24,
127 .codec_id = CODEC_ID_RAWVIDEO,
128 .v4l2_fmt = V4L2_PIX_FMT_RGB24,
129 },
130 {
131 .ff_fmt = PIX_FMT_BGRA,
132 .codec_id = CODEC_ID_RAWVIDEO,
133 .v4l2_fmt = V4L2_PIX_FMT_BGR32,
134 },
135 {
136 .ff_fmt = PIX_FMT_GRAY8,
137 .codec_id = CODEC_ID_RAWVIDEO,
138 .v4l2_fmt = V4L2_PIX_FMT_GREY,
139 },
140 {
141 .ff_fmt = PIX_FMT_NONE,
142 .codec_id = CODEC_ID_MJPEG,
143 .v4l2_fmt = V4L2_PIX_FMT_MJPEG,
144 },
145 {
146 .ff_fmt = PIX_FMT_NONE,
147 .codec_id = CODEC_ID_MJPEG,
148 .v4l2_fmt = V4L2_PIX_FMT_JPEG,
149 },
150 };
151
152 static int device_open(AVFormatContext *ctx, uint32_t *capabilities)
153 {
154 struct v4l2_capability cap;
155 int fd;
156 int res;
157 int flags = O_RDWR;
158
159 if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
160 flags |= O_NONBLOCK;
161 }
162 fd = open(ctx->filename, flags, 0);
163 if (fd < 0) {
164 av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
165 ctx->filename, strerror(errno));
166
167 return -1;
168 }
169
170 res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
171 // ENOIOCTLCMD definition only availble on __KERNEL__
172 if (res < 0 && errno == 515)
173 {
174 av_log(ctx, AV_LOG_ERROR, "QUERYCAP not implemented, probably V4L device but not supporting V4L2\n");
175 close(fd);
176
177 return -1;
178 }
179 if (res < 0) {
180 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
181 strerror(errno));
182 close(fd);
183
184 return -1;
185 }
186 if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
187 av_log(ctx, AV_LOG_ERROR, "Not a video capture device\n");
188 close(fd);
189
190 return -1;
191 }
192 *capabilities = cap.capabilities;
193
194 return fd;
195 }
196
197 static int device_init(AVFormatContext *ctx, int *width, int *height, uint32_t pix_fmt)
198 {
199 struct video_data *s = ctx->priv_data;
200 int fd = s->fd;
201 struct v4l2_format fmt;
202 int res;
203
204 memset(&fmt, 0, sizeof(struct v4l2_format));
205 fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
206 fmt.fmt.pix.width = *width;
207 fmt.fmt.pix.height = *height;
208 fmt.fmt.pix.pixelformat = pix_fmt;
209 fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
210 res = ioctl(fd, VIDIOC_S_FMT, &fmt);
211 if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
212 av_log(ctx, AV_LOG_INFO, "The V4L2 driver changed the video from %dx%d to %dx%d\n", *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
213 *width = fmt.fmt.pix.width;
214 *height = fmt.fmt.pix.height;
215 }
216
217 if (pix_fmt != fmt.fmt.pix.pixelformat) {
218 av_log(ctx, AV_LOG_DEBUG, "The V4L2 driver changed the pixel format from 0x%08X to 0x%08X\n", pix_fmt, fmt.fmt.pix.pixelformat);
219 res = -1;
220 }
221
222 return res;
223 }
224
225 static int first_field(int fd)
226 {
227 int res;
228 v4l2_std_id std;
229
230 res = ioctl(fd, VIDIOC_G_STD, &std);
231 if (res < 0) {
232 return 0;
233 }
234 if (std & V4L2_STD_NTSC) {
235 return 0;
236 }
237
238 return 1;
239 }
240
241 static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt, enum CodecID codec_id)
242 {
243 int i;
244
245 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
246 if ((codec_id == CODEC_ID_NONE ||
247 fmt_conversion_table[i].codec_id == codec_id) &&
248 (pix_fmt == PIX_FMT_NONE ||
249 fmt_conversion_table[i].ff_fmt == pix_fmt)) {
250 return fmt_conversion_table[i].v4l2_fmt;
251 }
252 }
253
254 return 0;
255 }
256
257 static enum PixelFormat fmt_v4l2ff(uint32_t v4l2_fmt, enum CodecID codec_id)
258 {
259 int i;
260
261 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
262 if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt &&
263 fmt_conversion_table[i].codec_id == codec_id) {
264 return fmt_conversion_table[i].ff_fmt;
265 }
266 }
267
268 return PIX_FMT_NONE;
269 }
270
271 static enum CodecID fmt_v4l2codec(uint32_t v4l2_fmt)
272 {
273 int i;
274
275 for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
276 if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt) {
277 return fmt_conversion_table[i].codec_id;
278 }
279 }
280
281 return CODEC_ID_NONE;
282 }
283
284 static int mmap_init(AVFormatContext *ctx)
285 {
286 struct video_data *s = ctx->priv_data;
287 struct v4l2_requestbuffers req;
288 int i, res;
289
290 memset(&req, 0, sizeof(struct v4l2_requestbuffers));
291 req.count = desired_video_buffers;
292 req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
293 req.memory = V4L2_MEMORY_MMAP;
294 res = ioctl (s->fd, VIDIOC_REQBUFS, &req);
295 if (res < 0) {
296 if (errno == EINVAL) {
297 av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
298 } else {
299 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
300 }
301
302 return -1;
303 }
304
305 if (req.count < 2) {
306 av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
307
308 return -1;
309 }
310 s->buffers = req.count;
311 s->buf_start = av_malloc(sizeof(void *) * s->buffers);
312 if (s->buf_start == NULL) {
313 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
314
315 return -1;
316 }
317 s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
318 if (s->buf_len == NULL) {
319 av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
320 av_free(s->buf_start);
321
322 return -1;
323 }
324
325 for (i = 0; i < req.count; i++) {
326 struct v4l2_buffer buf;
327
328 memset(&buf, 0, sizeof(struct v4l2_buffer));
329 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
330 buf.memory = V4L2_MEMORY_MMAP;
331 buf.index = i;
332 res = ioctl (s->fd, VIDIOC_QUERYBUF, &buf);
333 if (res < 0) {
334 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
335
336 return -1;
337 }
338
339 s->buf_len[i] = buf.length;
340 if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
341 av_log(ctx, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);
342
343 return -1;
344 }
345 s->buf_start[i] = mmap (NULL, buf.length,
346 PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);
347 if (s->buf_start[i] == MAP_FAILED) {
348 av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
349
350 return -1;
351 }
352 }
353
354 return 0;
355 }
356
357 static int read_init(AVFormatContext *ctx)
358 {
359 return -1;
360 }
361
362 static void mmap_release_buffer(AVPacket *pkt)
363 {
364 struct v4l2_buffer buf;
365 int res, fd;
366 struct buff_data *buf_descriptor = pkt->priv;
367
368 if (pkt->data == NULL) {
369 return;
370 }
371
372 memset(&buf, 0, sizeof(struct v4l2_buffer));
373 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
374 buf.memory = V4L2_MEMORY_MMAP;
375 buf.index = buf_descriptor->index;
376 fd = buf_descriptor->fd;
377 av_free(buf_descriptor);
378
379 res = ioctl (fd, VIDIOC_QBUF, &buf);
380 if (res < 0) {
381 av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
382 }
383 pkt->data = NULL;
384 pkt->size = 0;
385 }
386
387 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
388 {
389 struct video_data *s = ctx->priv_data;
390 struct v4l2_buffer buf;
391 struct buff_data *buf_descriptor;
392 int res;
393
394 memset(&buf, 0, sizeof(struct v4l2_buffer));
395 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
396 buf.memory = V4L2_MEMORY_MMAP;
397
398 /* FIXME: Some special treatment might be needed in case of loss of signal... */
399 while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
400 if (res < 0) {
401 if (errno == EAGAIN) {
402 pkt->size = 0;
403
404 return AVERROR(EAGAIN);
405 }
406 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));
407
408 return -1;
409 }
410 assert (buf.index < s->buffers);
411 if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
412 av_log(ctx, AV_LOG_ERROR, "The v4l2 frame is %d bytes, but %d bytes are expected\n", buf.bytesused, s->frame_size);
413
414 return -1;
415 }
416
417 /* Image is at s->buff_start[buf.index] */
418 pkt->data= s->buf_start[buf.index];
419 pkt->size = buf.bytesused;
420 pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
421 pkt->destruct = mmap_release_buffer;
422 buf_descriptor = av_malloc(sizeof(struct buff_data));
423 if (buf_descriptor == NULL) {
424 /* Something went wrong... Since av_malloc() failed, we cannot even
425 * allocate a buffer for memcopying into it
426 */
427 av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
428 res = ioctl (s->fd, VIDIOC_QBUF, &buf);
429
430 return -1;
431 }
432 buf_descriptor->fd = s->fd;
433 buf_descriptor->index = buf.index;
434 pkt->priv = buf_descriptor;
435
436 return s->buf_len[buf.index];
437 }
438
439 static int read_frame(AVFormatContext *ctx, AVPacket *pkt)
440 {
441 return -1;
442 }
443
444 static int mmap_start(AVFormatContext *ctx)
445 {
446 struct video_data *s = ctx->priv_data;
447 enum v4l2_buf_type type;
448 int i, res;
449
450 for (i = 0; i < s->buffers; i++) {
451 struct v4l2_buffer buf;
452
453 memset(&buf, 0, sizeof(struct v4l2_buffer));
454 buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
455 buf.memory = V4L2_MEMORY_MMAP;
456 buf.index = i;
457
458 res = ioctl (s->fd, VIDIOC_QBUF, &buf);
459 if (res < 0) {
460 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));
461
462 return -1;
463 }
464 }
465
466 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
467 res = ioctl (s->fd, VIDIOC_STREAMON, &type);
468 if (res < 0) {
469 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));
470
471 return -1;
472 }
473
474 return 0;
475 }
476
477 static void mmap_close(struct video_data *s)
478 {
479 enum v4l2_buf_type type;
480 int i;
481
482 type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
483 /* We do not check for the result, because we could
484 * not do anything about it anyway...
485 */
486 ioctl(s->fd, VIDIOC_STREAMOFF, &type);
487 for (i = 0; i < s->buffers; i++) {
488 munmap(s->buf_start[i], s->buf_len[i]);
489 }
490 av_free(s->buf_start);
491 av_free(s->buf_len);
492 }
493
494 static int v4l2_set_parameters( AVFormatContext *s1, AVFormatParameters *ap )
495 {
496 struct video_data *s = s1->priv_data;
497 struct v4l2_input input;
498 struct v4l2_standard standard;
499 int i;
500
501 if(ap->channel>=0) {
502 /* set tv video input */
503 memset (&input, 0, sizeof (input));
504 input.index = ap->channel;
505 if(ioctl (s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
506 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
507 return AVERROR(EIO);
508 }
509
510 av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
511 ap->channel, input.name);
512 if(ioctl (s->fd, VIDIOC_S_INPUT, &input.index) < 0 ) {
513 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set input(%d) failed\n",
514 ap->channel);
515 return AVERROR(EIO);
516 }
517 }
518
519 if(ap->standard) {
520 av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
521 ap->standard );
522 /* set tv standard */
523 memset (&standard, 0, sizeof (standard));
524 for(i=0;;i++) {
525 standard.index = i;
526 if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
527 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
528 ap->standard);
529 return AVERROR(EIO);
530 }
531
532 if(!strcasecmp(standard.name, ap->standard)) {
533 break;
534 }
535 }
536
537 av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
538 ap->standard, (uint64_t)standard.id);
539 if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
540 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
541 ap->standard);
542 return AVERROR(EIO);
543 }
544 }
545
546 return 0;
547 }
548
549 static uint32_t device_try_init(AVFormatContext *s1,
550 const AVFormatParameters *ap,
551 int *width,
552 int *height,
553 enum CodecID *codec_id)
554 {
555 uint32_t desired_format = fmt_ff2v4l(ap->pix_fmt, ap->video_codec_id);
556
557 if (desired_format == 0 ||
558 device_init(s1, width, height, desired_format) < 0) {
559 int i;
560
561 desired_format = 0;
562 for (i = 0; i<FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
563 if (ap->video_codec_id == CODEC_ID_NONE ||
564 fmt_conversion_table[i].codec_id == ap->video_codec_id) {
565 desired_format = fmt_conversion_table[i].v4l2_fmt;
566 if (device_init(s1, width, height, desired_format) >= 0) {
567 break;
568 }
569 desired_format = 0;
570 }
571 }
572 }
573 if (desired_format != 0) {
574 *codec_id = fmt_v4l2codec(desired_format);
575 assert(*codec_id != CODEC_ID_NONE);
576 }
577
578 return desired_format;
579 }
580
581 static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
582 {
583 struct video_data *s = s1->priv_data;
584 AVStream *st;
585 int width, height;
586 int res;
587 uint32_t desired_format, capabilities;
588 enum CodecID codec_id;
589
590 if (ap->width <= 0 || ap->height <= 0) {
591 av_log(s1, AV_LOG_ERROR, "Wrong size (%dx%d)\n", ap->width, ap->height);
592 return -1;
593 }
594
595 width = ap->width;
596 height = ap->height;
597
598 if(avcodec_check_dimensions(s1, ap->width, ap->height) < 0)
599 return -1;
600
601 st = av_new_stream(s1, 0);
602 if (!st) {
603 return AVERROR(ENOMEM);
604 }
605 av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
606
607 s->width = width;
608 s->height = height;
609
610 capabilities = 0;
611 s->fd = device_open(s1, &capabilities);
612 if (s->fd < 0) {
613 return AVERROR(EIO);
614 }
615 av_log(s1, AV_LOG_INFO, "[%d]Capabilities: %x\n", s->fd, capabilities);
616
617 desired_format = device_try_init(s1, ap, &width, &height, &codec_id);
618 if (desired_format == 0) {
619 av_log(s1, AV_LOG_ERROR, "Cannot find a proper format for "
620 "codec_id %d, pix_fmt %d.\n", ap->video_codec_id, ap->pix_fmt);
621 close(s->fd);
622
623 return AVERROR(EIO);
624 }
625 s->frame_format = desired_format;
626
627 if( v4l2_set_parameters( s1, ap ) < 0 )
628 return AVERROR(EIO);
629
630 st->codec->pix_fmt = fmt_v4l2ff(desired_format, codec_id);
631 s->frame_size = avpicture_get_size(st->codec->pix_fmt, width, height);
632 if (capabilities & V4L2_CAP_STREAMING) {
633 s->io_method = io_mmap;
634 res = mmap_init(s1);
635 if (res == 0) {
636 res = mmap_start(s1);
637 }
638 } else {
639 s->io_method = io_read;
640 res = read_init(s1);
641 }
642 if (res < 0) {
643 close(s->fd);
644
645 return AVERROR(EIO);
646 }
647 s->top_field_first = first_field(s->fd);
648
649 st->codec->codec_type = CODEC_TYPE_VIDEO;
650 st->codec->codec_id = codec_id;
651 st->codec->width = width;
652 st->codec->height = height;
653 st->codec->time_base.den = ap->time_base.den;
654 st->codec->time_base.num = ap->time_base.num;
655 st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
656
657 return 0;
658 }
659
660 static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
661 {
662 struct video_data *s = s1->priv_data;
663 int res;
664
665 if (s->io_method == io_mmap) {
666 av_init_packet(pkt);
667 res = mmap_read_frame(s1, pkt);
668 } else if (s->io_method == io_read) {
669 if (av_new_packet(pkt, s->frame_size) < 0)
670 return AVERROR(EIO);
671
672 res = read_frame(s1, pkt);
673 } else {
674 return AVERROR(EIO);
675 }
676 if (res < 0) {
677 return res;
678 }
679
680 if (s1->streams[0]->codec->coded_frame) {
681 s1->streams[0]->codec->coded_frame->interlaced_frame = 1;
682 s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;
683 }
684
685 return pkt->size;
686 }
687
688 static int v4l2_read_close(AVFormatContext *s1)
689 {
690 struct video_data *s = s1->priv_data;
691
692 if (s->io_method == io_mmap) {
693 mmap_close(s);
694 }
695
696 close(s->fd);
697 return 0;
698 }
699
700 AVInputFormat v4l2_demuxer = {
701 "video4linux2",
702 NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
703 sizeof(struct video_data),
704 NULL,
705 v4l2_read_header,
706 v4l2_read_packet,
707 v4l2_read_close,
708 .flags = AVFMT_NOFILE,
709 };