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 #include "avformat.h"
  30 #include <unistd.h>
  31 #include <fcntl.h>
  32 #include <sys/ioctl.h>
  33 #include <sys/mman.h>
  34 #include <sys/time.h>
  35 #include <asm/types.h>
  36 #include <linux/videodev2.h>
  37 #include <time.h>
  38
  39 static const int desired_video_buffers = 256;
  40
  41 enum io_method {
  42     io_read,
  43     io_mmap,
  44     io_userptr
  45 };
  46
  47 struct video_data {
  48     int fd;
  49     int frame_format; /* V4L2_PIX_FMT_* */
  50     enum io_method io_method;
  51     int width, height;
  52     int frame_rate;
  53     int frame_rate_base;
  54     int frame_size;
  55     int top_field_first;
  56
  57     int buffers;
  58     void **buf_start;
  59     unsigned int *buf_len;
  60 };
  61
  62 struct buff_data {
  63     int index;
  64     int fd;
  65 };
  66
  67 struct fmt_map {
  68     enum PixelFormat ff_fmt;
  69     int32_t v4l2_fmt;
  70 };
  71
  72 static struct fmt_map fmt_conversion_table[] = {
  73     {
  74         .ff_fmt = PIX_FMT_YUV420P,
  75         .v4l2_fmt = V4L2_PIX_FMT_YUV420,
  76     },
  77     {
  78         .ff_fmt = PIX_FMT_YUV422P,
  79         .v4l2_fmt = V4L2_PIX_FMT_YUV422P,
  80     },
  81     {
  82         .ff_fmt = PIX_FMT_YUYV422,
  83         .v4l2_fmt = V4L2_PIX_FMT_YUYV,
  84     },
  85     {
  86         .ff_fmt = PIX_FMT_UYVY422,
  87         .v4l2_fmt = V4L2_PIX_FMT_UYVY,
  88     },
  89     {
  90         .ff_fmt = PIX_FMT_YUV411P,
  91         .v4l2_fmt = V4L2_PIX_FMT_YUV411P,
  92     },
  93     {
  94         .ff_fmt = PIX_FMT_YUV410P,
  95         .v4l2_fmt = V4L2_PIX_FMT_YUV410,
  96     },
  97     {
  98         .ff_fmt = PIX_FMT_BGR24,
  99         .v4l2_fmt = V4L2_PIX_FMT_BGR24,
 100     },
 101     {
 102         .ff_fmt = PIX_FMT_RGB24,
 103         .v4l2_fmt = V4L2_PIX_FMT_RGB24,
 104     },
 105     /*
 106     {
 107         .ff_fmt = PIX_FMT_RGB32,
 108         .v4l2_fmt = V4L2_PIX_FMT_BGR32,
 109     },
 110     */
 111     {
 112         .ff_fmt = PIX_FMT_GRAY8,
 113         .v4l2_fmt = V4L2_PIX_FMT_GREY,
 114     },
 115 };
 116
 117 static int device_open(AVFormatContext *ctx, uint32_t *capabilities)
 118 {
 119     struct v4l2_capability cap;
 120     int fd;
 121     int res;
 122     int flags = O_RDWR;
 123
 124     if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
 125         flags |= O_NONBLOCK;
 126     }
 127     fd = open(ctx->filename, flags, 0);
 128     if (fd < 0) {
 129         av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
 130                  ctx->filename, strerror(errno));
 131
 132         return -1;
 133     }
 134
 135     res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
 136     // ENOIOCTLCMD definition only availble on __KERNEL__
 137     if (res < 0 && errno == 515)
 138     {
 139         av_log(ctx, AV_LOG_ERROR, "QUERYCAP not implemented, probably V4L device but not supporting V4L2\n");
 140         close(fd);
 141
 142         return -1;
 143     }
 144     if (res < 0) {
 145         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
 146                  strerror(errno));
 147         close(fd);
 148
 149         return -1;
 150     }
 151     if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
 152         av_log(ctx, AV_LOG_ERROR, "Not a video capture device\n");
 153         close(fd);
 154
 155         return -1;
 156     }
 157     *capabilities = cap.capabilities;
 158
 159     return fd;
 160 }
 161
 162 static int device_init(AVFormatContext *ctx, int *width, int *height, int pix_fmt)
 163 {
 164     struct video_data *s = ctx->priv_data;
 165     int fd = s->fd;
 166     struct v4l2_format fmt;
 167     int res;
 168
 169     memset(&fmt, 0, sizeof(struct v4l2_format));
 170     fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 171     fmt.fmt.pix.width = *width;
 172     fmt.fmt.pix.height = *height;
 173     fmt.fmt.pix.pixelformat = pix_fmt;
 174     fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
 175     res = ioctl(fd, VIDIOC_S_FMT, &fmt);
 176     if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
 177         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);
 178         *width = fmt.fmt.pix.width;
 179         *height = fmt.fmt.pix.height;
 180     }
 181
 182     return res;
 183 }
 184
 185 static int first_field(int fd)
 186 {
 187     int res;
 188     v4l2_std_id std;
 189
 190     res = ioctl(fd, VIDIOC_G_STD, &std);
 191     if (res < 0) {
 192         return 0;
 193     }
 194     if (std & V4L2_STD_NTSC) {
 195         return 0;
 196     }
 197
 198     return 1;
 199 }
 200
 201 static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt)
 202 {
 203     int i;
 204
 205     for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
 206         if (fmt_conversion_table[i].ff_fmt == pix_fmt) {
 207             return fmt_conversion_table[i].v4l2_fmt;
 208         }
 209     }
 210
 211     return 0;
 212 }
 213
 214 static enum PixelFormat fmt_v4l2ff(uint32_t pix_fmt)
 215 {
 216     int i;
 217
 218     for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
 219         if (fmt_conversion_table[i].v4l2_fmt == pix_fmt) {
 220             return fmt_conversion_table[i].ff_fmt;
 221         }
 222     }
 223
 224     return -1;
 225 }
 226
 227 static int mmap_init(AVFormatContext *ctx)
 228 {
 229     struct video_data *s = ctx->priv_data;
 230     struct v4l2_requestbuffers req;
 231     int i, res;
 232
 233     memset(&req, 0, sizeof(struct v4l2_requestbuffers));
 234     req.count = desired_video_buffers;
 235     req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 236     req.memory = V4L2_MEMORY_MMAP;
 237     res = ioctl (s->fd, VIDIOC_REQBUFS, &req);
 238     if (res < 0) {
 239         if (errno == EINVAL) {
 240             av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
 241         } else {
 242             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
 243         }
 244
 245         return -1;
 246     }
 247
 248     if (req.count < 2) {
 249         av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
 250
 251         return -1;
 252     }
 253     s->buffers = req.count;
 254     s->buf_start = av_malloc(sizeof(void *) * s->buffers);
 255     if (s->buf_start == NULL) {
 256         av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
 257
 258         return -1;
 259     }
 260     s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
 261     if (s->buf_len == NULL) {
 262         av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
 263         av_free(s->buf_start);
 264
 265         return -1;
 266     }
 267
 268     for (i = 0; i < req.count; i++) {
 269         struct v4l2_buffer buf;
 270
 271         memset(&buf, 0, sizeof(struct v4l2_buffer));
 272         buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 273         buf.memory = V4L2_MEMORY_MMAP;
 274         buf.index = i;
 275         res = ioctl (s->fd, VIDIOC_QUERYBUF, &buf);
 276         if (res < 0) {
 277             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
 278
 279             return -1;
 280         }
 281
 282         s->buf_len[i] = buf.length;
 283         if (s->buf_len[i] < s->frame_size) {
 284             av_log(ctx, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);
 285
 286             return -1;
 287         }
 288         s->buf_start[i] = mmap (NULL, buf.length,
 289                         PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);
 290         if (s->buf_start[i] == MAP_FAILED) {
 291             av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
 292
 293             return -1;
 294         }
 295     }
 296
 297     return 0;
 298 }
 299
 300 static int read_init(AVFormatContext *ctx)
 301 {
 302     return -1;
 303 }
 304
 305 static void mmap_release_buffer(AVPacket *pkt)
 306 {
 307     struct v4l2_buffer buf;
 308     int res, fd;
 309     struct buff_data *buf_descriptor = pkt->priv;
 310
 311     memset(&buf, 0, sizeof(struct v4l2_buffer));
 312     buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 313     buf.memory = V4L2_MEMORY_MMAP;
 314     buf.index = buf_descriptor->index;
 315     fd = buf_descriptor->fd;
 316     av_free(buf_descriptor);
 317
 318     res = ioctl (fd, VIDIOC_QBUF, &buf);
 319     if (res < 0) {
 320         av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
 321     }
 322     pkt->data = NULL;
 323     pkt->size = 0;
 324 }
 325
 326 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
 327 {
 328     struct video_data *s = ctx->priv_data;
 329     struct v4l2_buffer buf;
 330     struct buff_data *buf_descriptor;
 331     int res;
 332
 333     memset(&buf, 0, sizeof(struct v4l2_buffer));
 334     buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 335     buf.memory = V4L2_MEMORY_MMAP;
 336
 337     /* FIXME: Some special treatment might be needed in case of loss of signal... */
 338     while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
 339     if (res < 0) {
 340         if (errno == EAGAIN) {
 341             pkt->size = 0;
 342
 343             return AVERROR(EAGAIN);
 344         }
 345         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));
 346
 347         return -1;
 348     }
 349     assert (buf.index < s->buffers);
 350     if (buf.bytesused != s->frame_size) {
 351         av_log(ctx, AV_LOG_ERROR, "The v4l2 frame is %d bytes, but %d bytes are expected\n", buf.bytesused, s->frame_size);
 352
 353         return -1;
 354     }
 355
 356     /* Image is at s->buff_start[buf.index] */
 357     pkt->data= s->buf_start[buf.index];
 358     pkt->size = buf.bytesused;
 359     pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
 360     pkt->destruct = mmap_release_buffer;
 361     buf_descriptor = av_malloc(sizeof(struct buff_data));
 362     if (buf_descriptor == NULL) {
 363         /* Something went wrong... Since av_malloc() failed, we cannot even
 364          * allocate a buffer for memcopying into it
 365          */
 366         av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
 367         res = ioctl (s->fd, VIDIOC_QBUF, &buf);
 368
 369         return -1;
 370     }
 371     buf_descriptor->fd = s->fd;
 372     buf_descriptor->index = buf.index;
 373     pkt->priv = buf_descriptor;
 374
 375     return s->buf_len[buf.index];
 376 }
 377
 378 static int read_frame(AVFormatContext *ctx, AVPacket *pkt)
 379 {
 380     return -1;
 381 }
 382
 383 static int mmap_start(AVFormatContext *ctx)
 384 {
 385     struct video_data *s = ctx->priv_data;
 386     enum v4l2_buf_type type;
 387     int i, res;
 388
 389     for (i = 0; i < s->buffers; i++) {
 390         struct v4l2_buffer buf;
 391
 392         memset(&buf, 0, sizeof(struct v4l2_buffer));
 393         buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 394         buf.memory = V4L2_MEMORY_MMAP;
 395         buf.index  = i;
 396
 397         res = ioctl (s->fd, VIDIOC_QBUF, &buf);
 398         if (res < 0) {
 399             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));
 400
 401             return -1;
 402         }
 403     }
 404
 405     type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 406     res = ioctl (s->fd, VIDIOC_STREAMON, &type);
 407     if (res < 0) {
 408         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));
 409
 410         return -1;
 411     }
 412
 413     return 0;
 414 }
 415
 416 static void mmap_close(struct video_data *s)
 417 {
 418     enum v4l2_buf_type type;
 419     int i;
 420
 421     type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 422     /* We do not check for the result, because we could
 423      * not do anything about it anyway...
 424      */
 425     ioctl(s->fd, VIDIOC_STREAMOFF, &type);
 426     for (i = 0; i < s->buffers; i++) {
 427         munmap(s->buf_start[i], s->buf_len[i]);
 428     }
 429     av_free(s->buf_start);
 430     av_free(s->buf_len);
 431 }
 432
 433 static int v4l2_set_parameters( AVFormatContext *s1, AVFormatParameters *ap )
 434 {
 435     struct video_data *s = s1->priv_data;
 436     struct v4l2_input input;
 437     struct v4l2_standard standard;
 438     int i;
 439
 440     if(ap->channel>=0) {
 441         /* set tv video input */
 442         memset (&input, 0, sizeof (input));
 443         input.index = ap->channel;
 444         if(ioctl (s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
 445             av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
 446             return AVERROR(EIO);
 447         }
 448
 449         av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
 450                ap->channel, input.name);
 451         if(ioctl (s->fd, VIDIOC_S_INPUT, &input.index) < 0 ) {
 452             av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set input(%d) failed\n",
 453                    ap->channel);
 454             return AVERROR(EIO);
 455         }
 456     }
 457
 458     if(ap->standard) {
 459         av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
 460                ap->standard );
 461         /* set tv standard */
 462         memset (&standard, 0, sizeof (standard));
 463         for(i=0;;i++) {
 464             standard.index = i;
 465             if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
 466                 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
 467                        ap->standard);
 468                 return AVERROR(EIO);
 469             }
 470
 471             if(!strcasecmp(standard.name, ap->standard)) {
 472                 break;
 473             }
 474         }
 475
 476         av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
 477                ap->standard, standard.id);
 478         if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
 479             av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
 480                    ap->standard);
 481             return AVERROR(EIO);
 482         }
 483     }
 484
 485     return 0;
 486 }
 487
 488 static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
 489 {
 490     struct video_data *s = s1->priv_data;
 491     AVStream *st;
 492     int width, height;
 493     int res, frame_rate, frame_rate_base;
 494     uint32_t desired_format, capabilities;
 495
 496     if (ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {
 497         av_log(s1, AV_LOG_ERROR, "Missing/Wrong parameters\n");
 498
 499         return -1;
 500     }
 501
 502     width = ap->width;
 503     height = ap->height;
 504     frame_rate = ap->time_base.den;
 505     frame_rate_base = ap->time_base.num;
 506
 507     if((unsigned)width > 32767 || (unsigned)height > 32767) {
 508         av_log(s1, AV_LOG_ERROR, "Wrong size %dx%d\n", width, height);
 509
 510         return -1;
 511     }
 512
 513     st = av_new_stream(s1, 0);
 514     if (!st) {
 515         return AVERROR(ENOMEM);
 516     }
 517     av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
 518
 519     s->width = width;
 520     s->height = height;
 521     s->frame_rate      = frame_rate;
 522     s->frame_rate_base = frame_rate_base;
 523
 524     capabilities = 0;
 525     s->fd = device_open(s1, &capabilities);
 526     if (s->fd < 0) {
 527         av_free(st);
 528
 529         return AVERROR(EIO);
 530     }
 531     av_log(s1, AV_LOG_INFO, "[%d]Capabilities: %x\n", s->fd, capabilities);
 532
 533     desired_format = fmt_ff2v4l(ap->pix_fmt);
 534     if (desired_format == 0 || (device_init(s1, &width, &height, desired_format) < 0)) {
 535         int i, done;
 536
 537         done = 0; i = 0;
 538         while (!done) {
 539             desired_format = fmt_conversion_table[i].v4l2_fmt;
 540             if (device_init(s1, &width, &height, desired_format) < 0) {
 541                 desired_format = 0;
 542                 i++;
 543             } else {
 544                done = 1;
 545             }
 546             if (i == sizeof(fmt_conversion_table) / sizeof(struct fmt_map)) {
 547                done = 1;
 548             }
 549         }
 550     }
 551     if (desired_format == 0) {
 552         av_log(s1, AV_LOG_ERROR, "Cannot find a proper format.\n");
 553         close(s->fd);
 554         av_free(st);
 555
 556         return AVERROR(EIO);
 557     }
 558     s->frame_format = desired_format;
 559
 560     if( v4l2_set_parameters( s1, ap ) < 0 )
 561         return AVERROR(EIO);
 562
 563     st->codec->pix_fmt = fmt_v4l2ff(desired_format);
 564     s->frame_size = avpicture_get_size(st->codec->pix_fmt, width, height);
 565     if (capabilities & V4L2_CAP_STREAMING) {
 566         s->io_method = io_mmap;
 567         res = mmap_init(s1);
 568         if (res == 0) {
 569             res = mmap_start(s1);
 570         }
 571     } else {
 572         s->io_method = io_read;
 573         res = read_init(s1);
 574     }
 575     if (res < 0) {
 576         close(s->fd);
 577         av_free(st);
 578
 579         return AVERROR(EIO);
 580     }
 581     s->top_field_first = first_field(s->fd);
 582
 583     st->codec->codec_type = CODEC_TYPE_VIDEO;
 584     st->codec->codec_id = CODEC_ID_RAWVIDEO;
 585     st->codec->width = width;
 586     st->codec->height = height;
 587     st->codec->time_base.den = frame_rate;
 588     st->codec->time_base.num = frame_rate_base;
 589     st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
 590
 591     return 0;
 592 }
 593
 594 static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
 595 {
 596     struct video_data *s = s1->priv_data;
 597     int res;
 598
 599     if (s->io_method == io_mmap) {
 600         av_init_packet(pkt);
 601         res = mmap_read_frame(s1, pkt);
 602     } else if (s->io_method == io_read) {
 603         if (av_new_packet(pkt, s->frame_size) < 0)
 604             return AVERROR(EIO);
 605
 606         res = read_frame(s1, pkt);
 607     } else {
 608         return AVERROR(EIO);
 609     }
 610     if (res < 0) {
 611         return res;
 612     }
 613
 614     if (s1->streams[0]->codec->coded_frame) {
 615         s1->streams[0]->codec->coded_frame->interlaced_frame = 1;
 616         s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;
 617     }
 618
 619     return s->frame_size;
 620 }
 621
 622 static int v4l2_read_close(AVFormatContext *s1)
 623 {
 624     struct video_data *s = s1->priv_data;
 625
 626     if (s->io_method == io_mmap) {
 627         mmap_close(s);
 628     }
 629
 630     close(s->fd);
 631     return 0;
 632 }
 633
 634 AVInputFormat v4l2_demuxer = {
 635     "video4linux2",
 636     "video grab",
 637     sizeof(struct video_data),
 638     NULL,
 639     v4l2_read_header,
 640     v4l2_read_packet,
 641     v4l2_read_close,
 642     .flags = AVFMT_NOFILE,
 643 };