1 /*
2 * V4L2 buffer helper functions.
3 *
4 * Copyright (C) 2017 Alexis Ballier <aballier@gentoo.org>
5 * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz@linaro.org>
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24 #include <linux/videodev2.h>
25 #include <sys/ioctl.h>
26 #include <sys/mman.h>
27 #include <unistd.h>
28 #include <fcntl.h>
29 #include <poll.h>
30 #include "libavcodec/avcodec.h"
31 #include "libavutil/pixdesc.h"
32 #include "v4l2_context.h"
33 #include "v4l2_buffers.h"
34 #include "v4l2_m2m.h"
35
36 #define USEC_PER_SEC 1000000
37 static AVRational v4l2_timebase = { 1, USEC_PER_SEC };
38
buf_to_m2mctx(V4L2Buffer *buf)39 static inline V4L2m2mContext *buf_to_m2mctx(V4L2Buffer *buf)
40 {
41 return V4L2_TYPE_IS_OUTPUT(buf->context->type) ?
42 container_of(buf->context, V4L2m2mContext, output) :
43 container_of(buf->context, V4L2m2mContext, capture);
44 }
45
logger(V4L2Buffer *buf)46 static inline AVCodecContext *logger(V4L2Buffer *buf)
47 {
48 return buf_to_m2mctx(buf)->avctx;
49 }
50
v4l2_get_timebase(V4L2Buffer *avbuf)51 static inline AVRational v4l2_get_timebase(V4L2Buffer *avbuf)
52 {
53 V4L2m2mContext *s = buf_to_m2mctx(avbuf);
54
55 if (s->avctx->pkt_timebase.num)
56 return s->avctx->pkt_timebase;
57 return s->avctx->time_base;
58 }
59
v4l2_set_pts(V4L2Buffer *out, int64_t pts)60 static inline void v4l2_set_pts(V4L2Buffer *out, int64_t pts)
61 {
62 int64_t v4l2_pts;
63
64 if (pts == AV_NOPTS_VALUE)
65 pts = 0;
66
67 /* convert pts to v4l2 timebase */
68 v4l2_pts = av_rescale_q(pts, v4l2_get_timebase(out), v4l2_timebase);
69 out->buf.timestamp.tv_usec = v4l2_pts % USEC_PER_SEC;
70 out->buf.timestamp.tv_sec = v4l2_pts / USEC_PER_SEC;
71 }
72
v4l2_get_pts(V4L2Buffer *avbuf)73 static inline int64_t v4l2_get_pts(V4L2Buffer *avbuf)
74 {
75 int64_t v4l2_pts;
76
77 /* convert pts back to encoder timebase */
78 v4l2_pts = (int64_t)avbuf->buf.timestamp.tv_sec * USEC_PER_SEC +
79 avbuf->buf.timestamp.tv_usec;
80
81 return av_rescale_q(v4l2_pts, v4l2_timebase, v4l2_get_timebase(avbuf));
82 }
83
v4l2_get_color_primaries(V4L2Buffer *buf)84 static enum AVColorPrimaries v4l2_get_color_primaries(V4L2Buffer *buf)
85 {
86 enum v4l2_ycbcr_encoding ycbcr;
87 enum v4l2_colorspace cs;
88
89 cs = V4L2_TYPE_IS_MULTIPLANAR(buf->buf.type) ?
90 buf->context->format.fmt.pix_mp.colorspace :
91 buf->context->format.fmt.pix.colorspace;
92
93 ycbcr = V4L2_TYPE_IS_MULTIPLANAR(buf->buf.type) ?
94 buf->context->format.fmt.pix_mp.ycbcr_enc:
95 buf->context->format.fmt.pix.ycbcr_enc;
96
97 switch(ycbcr) {
98 case V4L2_YCBCR_ENC_XV709:
99 case V4L2_YCBCR_ENC_709: return AVCOL_PRI_BT709;
100 case V4L2_YCBCR_ENC_XV601:
101 case V4L2_YCBCR_ENC_601:return AVCOL_PRI_BT470M;
102 default:
103 break;
104 }
105
106 switch(cs) {
107 case V4L2_COLORSPACE_470_SYSTEM_BG: return AVCOL_PRI_BT470BG;
108 case V4L2_COLORSPACE_SMPTE170M: return AVCOL_PRI_SMPTE170M;
109 case V4L2_COLORSPACE_SMPTE240M: return AVCOL_PRI_SMPTE240M;
110 case V4L2_COLORSPACE_BT2020: return AVCOL_PRI_BT2020;
111 default:
112 break;
113 }
114
115 return AVCOL_PRI_UNSPECIFIED;
116 }
117
v4l2_get_color_range(V4L2Buffer *buf)118 static enum AVColorRange v4l2_get_color_range(V4L2Buffer *buf)
119 {
120 enum v4l2_quantization qt;
121
122 qt = V4L2_TYPE_IS_MULTIPLANAR(buf->buf.type) ?
123 buf->context->format.fmt.pix_mp.quantization :
124 buf->context->format.fmt.pix.quantization;
125
126 switch (qt) {
127 case V4L2_QUANTIZATION_LIM_RANGE: return AVCOL_RANGE_MPEG;
128 case V4L2_QUANTIZATION_FULL_RANGE: return AVCOL_RANGE_JPEG;
129 default:
130 break;
131 }
132
133 return AVCOL_RANGE_UNSPECIFIED;
134 }
135
v4l2_get_color_space(V4L2Buffer *buf)136 static enum AVColorSpace v4l2_get_color_space(V4L2Buffer *buf)
137 {
138 enum v4l2_ycbcr_encoding ycbcr;
139 enum v4l2_colorspace cs;
140
141 cs = V4L2_TYPE_IS_MULTIPLANAR(buf->buf.type) ?
142 buf->context->format.fmt.pix_mp.colorspace :
143 buf->context->format.fmt.pix.colorspace;
144
145 ycbcr = V4L2_TYPE_IS_MULTIPLANAR(buf->buf.type) ?
146 buf->context->format.fmt.pix_mp.ycbcr_enc:
147 buf->context->format.fmt.pix.ycbcr_enc;
148
149 switch(cs) {
150 case V4L2_COLORSPACE_SRGB: return AVCOL_SPC_RGB;
151 case V4L2_COLORSPACE_REC709: return AVCOL_SPC_BT709;
152 case V4L2_COLORSPACE_470_SYSTEM_M: return AVCOL_SPC_FCC;
153 case V4L2_COLORSPACE_470_SYSTEM_BG: return AVCOL_SPC_BT470BG;
154 case V4L2_COLORSPACE_SMPTE170M: return AVCOL_SPC_SMPTE170M;
155 case V4L2_COLORSPACE_SMPTE240M: return AVCOL_SPC_SMPTE240M;
156 case V4L2_COLORSPACE_BT2020:
157 if (ycbcr == V4L2_YCBCR_ENC_BT2020_CONST_LUM)
158 return AVCOL_SPC_BT2020_CL;
159 else
160 return AVCOL_SPC_BT2020_NCL;
161 default:
162 break;
163 }
164
165 return AVCOL_SPC_UNSPECIFIED;
166 }
167
v4l2_get_color_trc(V4L2Buffer *buf)168 static enum AVColorTransferCharacteristic v4l2_get_color_trc(V4L2Buffer *buf)
169 {
170 enum v4l2_ycbcr_encoding ycbcr;
171 enum v4l2_xfer_func xfer;
172 enum v4l2_colorspace cs;
173
174 cs = V4L2_TYPE_IS_MULTIPLANAR(buf->buf.type) ?
175 buf->context->format.fmt.pix_mp.colorspace :
176 buf->context->format.fmt.pix.colorspace;
177
178 ycbcr = V4L2_TYPE_IS_MULTIPLANAR(buf->buf.type) ?
179 buf->context->format.fmt.pix_mp.ycbcr_enc:
180 buf->context->format.fmt.pix.ycbcr_enc;
181
182 xfer = V4L2_TYPE_IS_MULTIPLANAR(buf->buf.type) ?
183 buf->context->format.fmt.pix_mp.xfer_func:
184 buf->context->format.fmt.pix.xfer_func;
185
186 switch (xfer) {
187 case V4L2_XFER_FUNC_709: return AVCOL_TRC_BT709;
188 case V4L2_XFER_FUNC_SRGB: return AVCOL_TRC_IEC61966_2_1;
189 default:
190 break;
191 }
192
193 switch (cs) {
194 case V4L2_COLORSPACE_470_SYSTEM_M: return AVCOL_TRC_GAMMA22;
195 case V4L2_COLORSPACE_470_SYSTEM_BG: return AVCOL_TRC_GAMMA28;
196 case V4L2_COLORSPACE_SMPTE170M: return AVCOL_TRC_SMPTE170M;
197 case V4L2_COLORSPACE_SMPTE240M: return AVCOL_TRC_SMPTE240M;
198 default:
199 break;
200 }
201
202 switch (ycbcr) {
203 case V4L2_YCBCR_ENC_XV709:
204 case V4L2_YCBCR_ENC_XV601: return AVCOL_TRC_BT1361_ECG;
205 default:
206 break;
207 }
208
209 return AVCOL_TRC_UNSPECIFIED;
210 }
211
v4l2_free_buffer(void *opaque, uint8_t *unused)212 static void v4l2_free_buffer(void *opaque, uint8_t *unused)
213 {
214 V4L2Buffer* avbuf = opaque;
215 V4L2m2mContext *s = buf_to_m2mctx(avbuf);
216
217 if (atomic_fetch_sub(&avbuf->context_refcount, 1) == 1) {
218 atomic_fetch_sub_explicit(&s->refcount, 1, memory_order_acq_rel);
219
220 if (s->reinit) {
221 if (!atomic_load(&s->refcount))
222 sem_post(&s->refsync);
223 } else {
224 if (s->draining && V4L2_TYPE_IS_OUTPUT(avbuf->context->type)) {
225 /* no need to queue more buffers to the driver */
226 avbuf->status = V4L2BUF_AVAILABLE;
227 }
228 else if (avbuf->context->streamon)
229 ff_v4l2_buffer_enqueue(avbuf);
230 }
231
232 av_buffer_unref(&avbuf->context_ref);
233 }
234 }
235
v4l2_buf_increase_ref(V4L2Buffer *in)236 static int v4l2_buf_increase_ref(V4L2Buffer *in)
237 {
238 V4L2m2mContext *s = buf_to_m2mctx(in);
239
240 if (in->context_ref)
241 atomic_fetch_add(&in->context_refcount, 1);
242 else {
243 in->context_ref = av_buffer_ref(s->self_ref);
244 if (!in->context_ref)
245 return AVERROR(ENOMEM);
246
247 in->context_refcount = 1;
248 }
249
250 in->status = V4L2BUF_RET_USER;
251 atomic_fetch_add_explicit(&s->refcount, 1, memory_order_relaxed);
252
253 return 0;
254 }
255
v4l2_buf_to_bufref(V4L2Buffer *in, int plane, AVBufferRef **buf)256 static int v4l2_buf_to_bufref(V4L2Buffer *in, int plane, AVBufferRef **buf)
257 {
258 int ret;
259
260 if (plane >= in->num_planes)
261 return AVERROR(EINVAL);
262
263 /* even though most encoders return 0 in data_offset encoding vp8 does require this value */
264 *buf = av_buffer_create((char *)in->plane_info[plane].mm_addr + in->planes[plane].data_offset,
265 in->plane_info[plane].length, v4l2_free_buffer, in, 0);
266 if (!*buf)
267 return AVERROR(ENOMEM);
268
269 ret = v4l2_buf_increase_ref(in);
270 if (ret)
271 av_buffer_unref(buf);
272
273 return ret;
274 }
275
v4l2_bufref_to_buf(V4L2Buffer *out, int plane, const uint8_t* data, int size, int offset)276 static int v4l2_bufref_to_buf(V4L2Buffer *out, int plane, const uint8_t* data, int size, int offset)
277 {
278 unsigned int bytesused, length;
279
280 if (plane >= out->num_planes)
281 return AVERROR(EINVAL);
282
283 length = out->plane_info[plane].length;
284 bytesused = FFMIN(size+offset, length);
285
286 memcpy((uint8_t*)out->plane_info[plane].mm_addr+offset, data, FFMIN(size, length-offset));
287
288 if (V4L2_TYPE_IS_MULTIPLANAR(out->buf.type)) {
289 out->planes[plane].bytesused = bytesused;
290 out->planes[plane].length = length;
291 } else {
292 out->buf.bytesused = bytesused;
293 out->buf.length = length;
294 }
295
296 return 0;
297 }
298
v4l2_buffer_buf_to_swframe(AVFrame *frame, V4L2Buffer *avbuf)299 static int v4l2_buffer_buf_to_swframe(AVFrame *frame, V4L2Buffer *avbuf)
300 {
301 int i, ret;
302
303 frame->format = avbuf->context->av_pix_fmt;
304
305 for (i = 0; i < avbuf->num_planes; i++) {
306 ret = v4l2_buf_to_bufref(avbuf, i, &frame->buf[i]);
307 if (ret)
308 return ret;
309
310 frame->linesize[i] = avbuf->plane_info[i].bytesperline;
311 frame->data[i] = frame->buf[i]->data;
312 }
313
314 /* fixup special cases */
315 switch (avbuf->context->av_pix_fmt) {
316 case AV_PIX_FMT_NV12:
317 case AV_PIX_FMT_NV21:
318 if (avbuf->num_planes > 1)
319 break;
320 frame->linesize[1] = avbuf->plane_info[0].bytesperline;
321 frame->data[1] = frame->buf[0]->data + avbuf->plane_info[0].bytesperline * avbuf->context->format.fmt.pix_mp.height;
322 break;
323
324 case AV_PIX_FMT_YUV420P:
325 if (avbuf->num_planes > 1)
326 break;
327 frame->linesize[1] = avbuf->plane_info[0].bytesperline >> 1;
328 frame->linesize[2] = avbuf->plane_info[0].bytesperline >> 1;
329 frame->data[1] = frame->buf[0]->data + avbuf->plane_info[0].bytesperline * avbuf->context->format.fmt.pix_mp.height;
330 frame->data[2] = frame->data[1] + ((avbuf->plane_info[0].bytesperline * avbuf->context->format.fmt.pix_mp.height) >> 2);
331 break;
332
333 default:
334 break;
335 }
336
337 return 0;
338 }
339
v4l2_buffer_swframe_to_buf(const AVFrame *frame, V4L2Buffer *out)340 static int v4l2_buffer_swframe_to_buf(const AVFrame *frame, V4L2Buffer *out)
341 {
342 int i, ret;
343 struct v4l2_format fmt = out->context->format;
344 int pixel_format = V4L2_TYPE_IS_MULTIPLANAR(fmt.type) ?
345 fmt.fmt.pix_mp.pixelformat : fmt.fmt.pix.pixelformat;
346 int height = V4L2_TYPE_IS_MULTIPLANAR(fmt.type) ?
347 fmt.fmt.pix_mp.height : fmt.fmt.pix.height;
348 int is_planar_format = 0;
349
350 switch (pixel_format) {
351 case V4L2_PIX_FMT_YUV420M:
352 case V4L2_PIX_FMT_YVU420M:
353 #ifdef V4L2_PIX_FMT_YUV422M
354 case V4L2_PIX_FMT_YUV422M:
355 #endif
356 #ifdef V4L2_PIX_FMT_YVU422M
357 case V4L2_PIX_FMT_YVU422M:
358 #endif
359 #ifdef V4L2_PIX_FMT_YUV444M
360 case V4L2_PIX_FMT_YUV444M:
361 #endif
362 #ifdef V4L2_PIX_FMT_YVU444M
363 case V4L2_PIX_FMT_YVU444M:
364 #endif
365 case V4L2_PIX_FMT_NV12M:
366 case V4L2_PIX_FMT_NV21M:
367 case V4L2_PIX_FMT_NV12MT_16X16:
368 case V4L2_PIX_FMT_NV12MT:
369 case V4L2_PIX_FMT_NV16M:
370 case V4L2_PIX_FMT_NV61M:
371 is_planar_format = 1;
372 }
373
374 if (!is_planar_format) {
375 const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(frame->format);
376 int planes_nb = 0;
377 int offset = 0;
378
379 for (i = 0; i < desc->nb_components; i++)
380 planes_nb = FFMAX(planes_nb, desc->comp[i].plane + 1);
381
382 for (i = 0; i < planes_nb; i++) {
383 int size, h = height;
384 if (i == 1 || i == 2) {
385 h = AV_CEIL_RSHIFT(h, desc->log2_chroma_h);
386 }
387 size = frame->linesize[i] * h;
388 ret = v4l2_bufref_to_buf(out, 0, frame->data[i], size, offset);
389 if (ret)
390 return ret;
391 offset += size;
392 }
393 return 0;
394 }
395
396 for (i = 0; i < out->num_planes; i++) {
397 ret = v4l2_bufref_to_buf(out, i, frame->buf[i]->data, frame->buf[i]->size, 0);
398 if (ret)
399 return ret;
400 }
401
402 return 0;
403 }
404
405 /******************************************************************************
406 *
407 * V4L2Buffer interface
408 *
409 ******************************************************************************/
410
ff_v4l2_buffer_avframe_to_buf(const AVFrame *frame, V4L2Buffer *out)411 int ff_v4l2_buffer_avframe_to_buf(const AVFrame *frame, V4L2Buffer *out)
412 {
413 v4l2_set_pts(out, frame->pts);
414
415 return v4l2_buffer_swframe_to_buf(frame, out);
416 }
417
ff_v4l2_buffer_buf_to_avframe(AVFrame *frame, V4L2Buffer *avbuf)418 int ff_v4l2_buffer_buf_to_avframe(AVFrame *frame, V4L2Buffer *avbuf)
419 {
420 int ret;
421
422 av_frame_unref(frame);
423
424 /* 1. get references to the actual data */
425 ret = v4l2_buffer_buf_to_swframe(frame, avbuf);
426 if (ret)
427 return ret;
428
429 /* 2. get frame information */
430 frame->key_frame = !!(avbuf->buf.flags & V4L2_BUF_FLAG_KEYFRAME);
431 frame->color_primaries = v4l2_get_color_primaries(avbuf);
432 frame->colorspace = v4l2_get_color_space(avbuf);
433 frame->color_range = v4l2_get_color_range(avbuf);
434 frame->color_trc = v4l2_get_color_trc(avbuf);
435 frame->pts = v4l2_get_pts(avbuf);
436 frame->pkt_dts = AV_NOPTS_VALUE;
437
438 /* these values are updated also during re-init in v4l2_process_driver_event */
439 frame->height = avbuf->context->height;
440 frame->width = avbuf->context->width;
441 frame->sample_aspect_ratio = avbuf->context->sample_aspect_ratio;
442
443 /* 3. report errors upstream */
444 if (avbuf->buf.flags & V4L2_BUF_FLAG_ERROR) {
445 av_log(logger(avbuf), AV_LOG_ERROR, "%s: driver decode error\n", avbuf->context->name);
446 frame->decode_error_flags |= FF_DECODE_ERROR_INVALID_BITSTREAM;
447 }
448
449 return 0;
450 }
451
ff_v4l2_buffer_buf_to_avpkt(AVPacket *pkt, V4L2Buffer *avbuf)452 int ff_v4l2_buffer_buf_to_avpkt(AVPacket *pkt, V4L2Buffer *avbuf)
453 {
454 int ret;
455
456 av_packet_unref(pkt);
457 ret = v4l2_buf_to_bufref(avbuf, 0, &pkt->buf);
458 if (ret)
459 return ret;
460
461 pkt->size = V4L2_TYPE_IS_MULTIPLANAR(avbuf->buf.type) ? avbuf->buf.m.planes[0].bytesused : avbuf->buf.bytesused;
462 pkt->data = pkt->buf->data;
463
464 if (avbuf->buf.flags & V4L2_BUF_FLAG_KEYFRAME)
465 pkt->flags |= AV_PKT_FLAG_KEY;
466
467 if (avbuf->buf.flags & V4L2_BUF_FLAG_ERROR) {
468 av_log(logger(avbuf), AV_LOG_ERROR, "%s driver encode error\n", avbuf->context->name);
469 pkt->flags |= AV_PKT_FLAG_CORRUPT;
470 }
471
472 pkt->dts = pkt->pts = v4l2_get_pts(avbuf);
473
474 return 0;
475 }
476
ff_v4l2_buffer_avpkt_to_buf(const AVPacket *pkt, V4L2Buffer *out)477 int ff_v4l2_buffer_avpkt_to_buf(const AVPacket *pkt, V4L2Buffer *out)
478 {
479 int ret;
480
481 ret = v4l2_bufref_to_buf(out, 0, pkt->data, pkt->size, 0);
482 if (ret)
483 return ret;
484
485 v4l2_set_pts(out, pkt->pts);
486
487 if (pkt->flags & AV_PKT_FLAG_KEY)
488 out->flags = V4L2_BUF_FLAG_KEYFRAME;
489
490 return 0;
491 }
492
ff_v4l2_buffer_initialize(V4L2Buffer* avbuf, int index)493 int ff_v4l2_buffer_initialize(V4L2Buffer* avbuf, int index)
494 {
495 V4L2Context *ctx = avbuf->context;
496 int ret, i;
497
498 avbuf->buf.memory = V4L2_MEMORY_MMAP;
499 avbuf->buf.type = ctx->type;
500 avbuf->buf.index = index;
501
502 if (V4L2_TYPE_IS_MULTIPLANAR(ctx->type)) {
503 avbuf->buf.length = VIDEO_MAX_PLANES;
504 avbuf->buf.m.planes = avbuf->planes;
505 }
506
507 ret = ioctl(buf_to_m2mctx(avbuf)->fd, VIDIOC_QUERYBUF, &avbuf->buf);
508 if (ret < 0)
509 return AVERROR(errno);
510
511 if (V4L2_TYPE_IS_MULTIPLANAR(ctx->type)) {
512 avbuf->num_planes = 0;
513 /* in MP, the V4L2 API states that buf.length means num_planes */
514 for (i = 0; i < avbuf->buf.length; i++) {
515 if (avbuf->buf.m.planes[i].length)
516 avbuf->num_planes++;
517 }
518 } else
519 avbuf->num_planes = 1;
520
521 for (i = 0; i < avbuf->num_planes; i++) {
522
523 avbuf->plane_info[i].bytesperline = V4L2_TYPE_IS_MULTIPLANAR(ctx->type) ?
524 ctx->format.fmt.pix_mp.plane_fmt[i].bytesperline :
525 ctx->format.fmt.pix.bytesperline;
526
527 if (V4L2_TYPE_IS_MULTIPLANAR(ctx->type)) {
528 avbuf->plane_info[i].length = avbuf->buf.m.planes[i].length;
529 avbuf->plane_info[i].mm_addr = mmap(NULL, avbuf->buf.m.planes[i].length,
530 PROT_READ | PROT_WRITE, MAP_SHARED,
531 buf_to_m2mctx(avbuf)->fd, avbuf->buf.m.planes[i].m.mem_offset);
532 } else {
533 avbuf->plane_info[i].length = avbuf->buf.length;
534 avbuf->plane_info[i].mm_addr = mmap(NULL, avbuf->buf.length,
535 PROT_READ | PROT_WRITE, MAP_SHARED,
536 buf_to_m2mctx(avbuf)->fd, avbuf->buf.m.offset);
537 }
538
539 if (avbuf->plane_info[i].mm_addr == MAP_FAILED)
540 return AVERROR(ENOMEM);
541 }
542
543 avbuf->status = V4L2BUF_AVAILABLE;
544
545 if (V4L2_TYPE_IS_OUTPUT(ctx->type))
546 return 0;
547
548 if (V4L2_TYPE_IS_MULTIPLANAR(ctx->type)) {
549 avbuf->buf.m.planes = avbuf->planes;
550 avbuf->buf.length = avbuf->num_planes;
551
552 } else {
553 avbuf->buf.bytesused = avbuf->planes[0].bytesused;
554 avbuf->buf.length = avbuf->planes[0].length;
555 }
556
557 return ff_v4l2_buffer_enqueue(avbuf);
558 }
559
ff_v4l2_buffer_enqueue(V4L2Buffer* avbuf)560 int ff_v4l2_buffer_enqueue(V4L2Buffer* avbuf)
561 {
562 int ret;
563
564 avbuf->buf.flags = avbuf->flags;
565
566 ret = ioctl(buf_to_m2mctx(avbuf)->fd, VIDIOC_QBUF, &avbuf->buf);
567 if (ret < 0)
568 return AVERROR(errno);
569
570 avbuf->status = V4L2BUF_IN_DRIVER;
571
572 return 0;
573 }
574