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 #include <asm/types.h>
  39 #include <linux/videodev2.h>
  40 #include <time.h>
  41 #include <strings.h>
  42
  43 static const int desired_video_buffers = 256;
  44
  45 enum io_method {
  46     io_read,
  47     io_mmap,
  48     io_userptr
  49 };
  50
  51 struct video_data {
  52     int fd;
  53     int frame_format; /* V4L2_PIX_FMT_* */
  54     enum io_method io_method;
  55     int width, height;
  56     int frame_rate;
  57     int frame_rate_base;
  58     int frame_size;
  59     int top_field_first;
  60
  61     int buffers;
  62     void **buf_start;
  63     unsigned int *buf_len;
  64 };
  65
  66 struct buff_data {
  67     int index;
  68     int fd;
  69 };
  70
  71 struct fmt_map {
  72     enum PixelFormat ff_fmt;
  73     int32_t v4l2_fmt;
  74 };
  75
  76 static struct fmt_map fmt_conversion_table[] = {
  77     {
  78         .ff_fmt = PIX_FMT_YUV420P,
  79         .v4l2_fmt = V4L2_PIX_FMT_YUV420,
  80     },
  81     {
  82         .ff_fmt = PIX_FMT_YUV422P,
  83         .v4l2_fmt = V4L2_PIX_FMT_YUV422P,
  84     },
  85     {
  86         .ff_fmt = PIX_FMT_YUYV422,
  87         .v4l2_fmt = V4L2_PIX_FMT_YUYV,
  88     },
  89     {
  90         .ff_fmt = PIX_FMT_UYVY422,
  91         .v4l2_fmt = V4L2_PIX_FMT_UYVY,
  92     },
  93     {
  94         .ff_fmt = PIX_FMT_YUV411P,
  95         .v4l2_fmt = V4L2_PIX_FMT_YUV411P,
  96     },
  97     {
  98         .ff_fmt = PIX_FMT_YUV410P,
  99         .v4l2_fmt = V4L2_PIX_FMT_YUV410,
 100     },
 101     {
 102         .ff_fmt = PIX_FMT_BGR24,
 103         .v4l2_fmt = V4L2_PIX_FMT_BGR24,
 104     },
 105     {
 106         .ff_fmt = PIX_FMT_RGB24,
 107         .v4l2_fmt = V4L2_PIX_FMT_RGB24,
 108     },
 109     /*
 110     {
 111         .ff_fmt = PIX_FMT_RGB32,
 112         .v4l2_fmt = V4L2_PIX_FMT_BGR32,
 113     },
 114     */
 115     {
 116         .ff_fmt = PIX_FMT_GRAY8,
 117         .v4l2_fmt = V4L2_PIX_FMT_GREY,
 118     },
 119 };
 120
 121 static int device_open(AVFormatContext *ctx, uint32_t *capabilities)
 122 {
 123     struct v4l2_capability cap;
 124     int fd;
 125     int res;
 126     int flags = O_RDWR;
 127
 128     if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
 129         flags |= O_NONBLOCK;
 130     }
 131     fd = open(ctx->filename, flags, 0);
 132     if (fd < 0) {
 133         av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
 134                  ctx->filename, strerror(errno));
 135
 136         return -1;
 137     }
 138
 139     res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
 140     // ENOIOCTLCMD definition only availble on __KERNEL__
 141     if (res < 0 && errno == 515)
 142     {
 143         av_log(ctx, AV_LOG_ERROR, "QUERYCAP not implemented, probably V4L device but not supporting V4L2\n");
 144         close(fd);
 145
 146         return -1;
 147     }
 148     if (res < 0) {
 149         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
 150                  strerror(errno));
 151         close(fd);
 152
 153         return -1;
 154     }
 155     if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
 156         av_log(ctx, AV_LOG_ERROR, "Not a video capture device\n");
 157         close(fd);
 158
 159         return -1;
 160     }
 161     *capabilities = cap.capabilities;
 162
 163     return fd;
 164 }
 165
 166 static int device_init(AVFormatContext *ctx, int *width, int *height, int pix_fmt)
 167 {
 168     struct video_data *s = ctx->priv_data;
 169     int fd = s->fd;
 170     struct v4l2_format fmt;
 171     int res;
 172
 173     memset(&fmt, 0, sizeof(struct v4l2_format));
 174     fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 175     fmt.fmt.pix.width = *width;
 176     fmt.fmt.pix.height = *height;
 177     fmt.fmt.pix.pixelformat = pix_fmt;
 178     fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
 179     res = ioctl(fd, VIDIOC_S_FMT, &fmt);
 180     if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
 181         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);
 182         *width = fmt.fmt.pix.width;
 183         *height = fmt.fmt.pix.height;
 184     }
 185
 186     return res;
 187 }
 188
 189 static int first_field(int fd)
 190 {
 191     int res;
 192     v4l2_std_id std;
 193
 194     res = ioctl(fd, VIDIOC_G_STD, &std);
 195     if (res < 0) {
 196         return 0;
 197     }
 198     if (std & V4L2_STD_NTSC) {
 199         return 0;
 200     }
 201
 202     return 1;
 203 }
 204
 205 static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt)
 206 {
 207     int i;
 208
 209     for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
 210         if (fmt_conversion_table[i].ff_fmt == pix_fmt) {
 211             return fmt_conversion_table[i].v4l2_fmt;
 212         }
 213     }
 214
 215     return 0;
 216 }
 217
 218 static enum PixelFormat fmt_v4l2ff(uint32_t pix_fmt)
 219 {
 220     int i;
 221
 222     for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
 223         if (fmt_conversion_table[i].v4l2_fmt == pix_fmt) {
 224             return fmt_conversion_table[i].ff_fmt;
 225         }
 226     }
 227
 228     return PIX_FMT_NONE;
 229 }
 230
 231 static int mmap_init(AVFormatContext *ctx)
 232 {
 233     struct video_data *s = ctx->priv_data;
 234     struct v4l2_requestbuffers req;
 235     int i, res;
 236
 237     memset(&req, 0, sizeof(struct v4l2_requestbuffers));
 238     req.count = desired_video_buffers;
 239     req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 240     req.memory = V4L2_MEMORY_MMAP;
 241     res = ioctl (s->fd, VIDIOC_REQBUFS, &req);
 242     if (res < 0) {
 243         if (errno == EINVAL) {
 244             av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
 245         } else {
 246             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
 247         }
 248
 249         return -1;
 250     }
 251
 252     if (req.count < 2) {
 253         av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
 254
 255         return -1;
 256     }
 257     s->buffers = req.count;
 258     s->buf_start = av_malloc(sizeof(void *) * s->buffers);
 259     if (s->buf_start == NULL) {
 260         av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
 261
 262         return -1;
 263     }
 264     s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
 265     if (s->buf_len == NULL) {
 266         av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
 267         av_free(s->buf_start);
 268
 269         return -1;
 270     }
 271
 272     for (i = 0; i < req.count; i++) {
 273         struct v4l2_buffer buf;
 274
 275         memset(&buf, 0, sizeof(struct v4l2_buffer));
 276         buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 277         buf.memory = V4L2_MEMORY_MMAP;
 278         buf.index = i;
 279         res = ioctl (s->fd, VIDIOC_QUERYBUF, &buf);
 280         if (res < 0) {
 281             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
 282
 283             return -1;
 284         }
 285
 286         s->buf_len[i] = buf.length;
 287         if (s->buf_len[i] < s->frame_size) {
 288             av_log(ctx, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);
 289
 290             return -1;
 291         }
 292         s->buf_start[i] = mmap (NULL, buf.length,
 293                         PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);
 294         if (s->buf_start[i] == MAP_FAILED) {
 295             av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
 296
 297             return -1;
 298         }
 299     }
 300
 301     return 0;
 302 }
 303
 304 static int read_init(AVFormatContext *ctx)
 305 {
 306     return -1;
 307 }
 308
 309 static void mmap_release_buffer(AVPacket *pkt)
 310 {
 311     struct v4l2_buffer buf;
 312     int res, fd;
 313     struct buff_data *buf_descriptor = pkt->priv;
 314
 315     memset(&buf, 0, sizeof(struct v4l2_buffer));
 316     buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 317     buf.memory = V4L2_MEMORY_MMAP;
 318     buf.index = buf_descriptor->index;
 319     fd = buf_descriptor->fd;
 320     av_free(buf_descriptor);
 321
 322     res = ioctl (fd, VIDIOC_QBUF, &buf);
 323     if (res < 0) {
 324         av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
 325     }
 326     pkt->data = NULL;
 327     pkt->size = 0;
 328 }
 329
 330 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
 331 {
 332     struct video_data *s = ctx->priv_data;
 333     struct v4l2_buffer buf;
 334     struct buff_data *buf_descriptor;
 335     int res;
 336
 337     memset(&buf, 0, sizeof(struct v4l2_buffer));
 338     buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 339     buf.memory = V4L2_MEMORY_MMAP;
 340
 341     /* FIXME: Some special treatment might be needed in case of loss of signal... */
 342     while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
 343     if (res < 0) {
 344         if (errno == EAGAIN) {
 345             pkt->size = 0;
 346
 347             return AVERROR(EAGAIN);
 348         }
 349         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));
 350
 351         return -1;
 352     }
 353     assert (buf.index < s->buffers);
 354     if (buf.bytesused != s->frame_size) {
 355         av_log(ctx, AV_LOG_ERROR, "The v4l2 frame is %d bytes, but %d bytes are expected\n", buf.bytesused, s->frame_size);
 356
 357         return -1;
 358     }
 359
 360     /* Image is at s->buff_start[buf.index] */
 361     pkt->data= s->buf_start[buf.index];
 362     pkt->size = buf.bytesused;
 363     pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
 364     pkt->destruct = mmap_release_buffer;
 365     buf_descriptor = av_malloc(sizeof(struct buff_data));
 366     if (buf_descriptor == NULL) {
 367         /* Something went wrong... Since av_malloc() failed, we cannot even
 368          * allocate a buffer for memcopying into it
 369          */
 370         av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
 371         res = ioctl (s->fd, VIDIOC_QBUF, &buf);
 372
 373         return -1;
 374     }
 375     buf_descriptor->fd = s->fd;
 376     buf_descriptor->index = buf.index;
 377     pkt->priv = buf_descriptor;
 378
 379     return s->buf_len[buf.index];
 380 }
 381
 382 static int read_frame(AVFormatContext *ctx, AVPacket *pkt)
 383 {
 384     return -1;
 385 }
 386
 387 static int mmap_start(AVFormatContext *ctx)
 388 {
 389     struct video_data *s = ctx->priv_data;
 390     enum v4l2_buf_type type;
 391     int i, res;
 392
 393     for (i = 0; i < s->buffers; i++) {
 394         struct v4l2_buffer buf;
 395
 396         memset(&buf, 0, sizeof(struct v4l2_buffer));
 397         buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 398         buf.memory = V4L2_MEMORY_MMAP;
 399         buf.index  = i;
 400
 401         res = ioctl (s->fd, VIDIOC_QBUF, &buf);
 402         if (res < 0) {
 403             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));
 404
 405             return -1;
 406         }
 407     }
 408
 409     type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 410     res = ioctl (s->fd, VIDIOC_STREAMON, &type);
 411     if (res < 0) {
 412         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));
 413
 414         return -1;
 415     }
 416
 417     return 0;
 418 }
 419
 420 static void mmap_close(struct video_data *s)
 421 {
 422     enum v4l2_buf_type type;
 423     int i;
 424
 425     type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 426     /* We do not check for the result, because we could
 427      * not do anything about it anyway...
 428      */
 429     ioctl(s->fd, VIDIOC_STREAMOFF, &type);
 430     for (i = 0; i < s->buffers; i++) {
 431         munmap(s->buf_start[i], s->buf_len[i]);
 432     }
 433     av_free(s->buf_start);
 434     av_free(s->buf_len);
 435 }
 436
 437 static int v4l2_set_parameters( AVFormatContext *s1, AVFormatParameters *ap )
 438 {
 439     struct video_data *s = s1->priv_data;
 440     struct v4l2_input input;
 441     struct v4l2_standard standard;
 442     int i;
 443
 444     if(ap->channel>=0) {
 445         /* set tv video input */
 446         memset (&input, 0, sizeof (input));
 447         input.index = ap->channel;
 448         if(ioctl (s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
 449             av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
 450             return AVERROR(EIO);
 451         }
 452
 453         av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
 454                ap->channel, input.name);
 455         if(ioctl (s->fd, VIDIOC_S_INPUT, &input.index) < 0 ) {
 456             av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set input(%d) failed\n",
 457                    ap->channel);
 458             return AVERROR(EIO);
 459         }
 460     }
 461
 462     if(ap->standard) {
 463         av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
 464                ap->standard );
 465         /* set tv standard */
 466         memset (&standard, 0, sizeof (standard));
 467         for(i=0;;i++) {
 468             standard.index = i;
 469             if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
 470                 av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
 471                        ap->standard);
 472                 return AVERROR(EIO);
 473             }
 474
 475             if(!strcasecmp(standard.name, ap->standard)) {
 476                 break;
 477             }
 478         }
 479
 480         av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
 481                ap->standard, standard.id);
 482         if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
 483             av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl set standard(%s) failed\n",
 484                    ap->standard);
 485             return AVERROR(EIO);
 486         }
 487     }
 488
 489     return 0;
 490 }
 491
 492 static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
 493 {
 494     struct video_data *s = s1->priv_data;
 495     AVStream *st;
 496     int width, height;
 497     int res, frame_rate, frame_rate_base;
 498     uint32_t desired_format, capabilities;
 499
 500     if (ap->width <= 0 || ap->height <= 0) {
 501         av_log(s1, AV_LOG_ERROR, "Wrong size (%dx%d)\n", ap->width, ap->height);
 502         return -1;
 503     }
 504     if (ap->time_base.den <= 0) {
 505         av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);
 506         return -1;
 507     }
 508
 509     width = ap->width;
 510     height = ap->height;
 511     frame_rate = ap->time_base.den;
 512     frame_rate_base = ap->time_base.num;
 513
 514     if((unsigned)width > 32767 || (unsigned)height > 32767) {
 515         av_log(s1, AV_LOG_ERROR, "Wrong size (%dx%d)\n", width, height);
 516
 517         return -1;
 518     }
 519
 520     st = av_new_stream(s1, 0);
 521     if (!st) {
 522         return AVERROR(ENOMEM);
 523     }
 524     av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
 525
 526     s->width = width;
 527     s->height = height;
 528     s->frame_rate      = frame_rate;
 529     s->frame_rate_base = frame_rate_base;
 530
 531     capabilities = 0;
 532     s->fd = device_open(s1, &capabilities);
 533     if (s->fd < 0) {
 534         return AVERROR(EIO);
 535     }
 536     av_log(s1, AV_LOG_INFO, "[%d]Capabilities: %x\n", s->fd, capabilities);
 537
 538     desired_format = fmt_ff2v4l(ap->pix_fmt);
 539     if (desired_format == 0 || (device_init(s1, &width, &height, desired_format) < 0)) {
 540         int i, done;
 541
 542         done = 0; i = 0;
 543         while (!done) {
 544             desired_format = fmt_conversion_table[i].v4l2_fmt;
 545             if (device_init(s1, &width, &height, desired_format) < 0) {
 546                 desired_format = 0;
 547                 i++;
 548             } else {
 549                done = 1;
 550             }
 551             if (i == sizeof(fmt_conversion_table) / sizeof(struct fmt_map)) {
 552                done = 1;
 553             }
 554         }
 555     }
 556     if (desired_format == 0) {
 557         av_log(s1, AV_LOG_ERROR, "Cannot find a proper format.\n");
 558         close(s->fd);
 559
 560         return AVERROR(EIO);
 561     }
 562     s->frame_format = desired_format;
 563
 564     if( v4l2_set_parameters( s1, ap ) < 0 )
 565         return AVERROR(EIO);
 566
 567     st->codec->pix_fmt = fmt_v4l2ff(desired_format);
 568     s->frame_size = avpicture_get_size(st->codec->pix_fmt, width, height);
 569     if (capabilities & V4L2_CAP_STREAMING) {
 570         s->io_method = io_mmap;
 571         res = mmap_init(s1);
 572         if (res == 0) {
 573             res = mmap_start(s1);
 574         }
 575     } else {
 576         s->io_method = io_read;
 577         res = read_init(s1);
 578     }
 579     if (res < 0) {
 580         close(s->fd);
 581
 582         return AVERROR(EIO);
 583     }
 584     s->top_field_first = first_field(s->fd);
 585
 586     st->codec->codec_type = CODEC_TYPE_VIDEO;
 587     st->codec->codec_id = CODEC_ID_RAWVIDEO;
 588     st->codec->width = width;
 589     st->codec->height = height;
 590     st->codec->time_base.den = frame_rate;
 591     st->codec->time_base.num = frame_rate_base;
 592     st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
 593
 594     return 0;
 595 }
 596
 597 static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
 598 {
 599     struct video_data *s = s1->priv_data;
 600     int res;
 601
 602     if (s->io_method == io_mmap) {
 603         av_init_packet(pkt);
 604         res = mmap_read_frame(s1, pkt);
 605     } else if (s->io_method == io_read) {
 606         if (av_new_packet(pkt, s->frame_size) < 0)
 607             return AVERROR(EIO);
 608
 609         res = read_frame(s1, pkt);
 610     } else {
 611         return AVERROR(EIO);
 612     }
 613     if (res < 0) {
 614         return res;
 615     }
 616
 617     if (s1->streams[0]->codec->coded_frame) {
 618         s1->streams[0]->codec->coded_frame->interlaced_frame = 1;
 619         s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;
 620     }
 621
 622     return s->frame_size;
 623 }
 624
 625 static int v4l2_read_close(AVFormatContext *s1)
 626 {
 627     struct video_data *s = s1->priv_data;
 628
 629     if (s->io_method == io_mmap) {
 630         mmap_close(s);
 631     }
 632
 633     close(s->fd);
 634     return 0;
 635 }
 636
 637 AVInputFormat v4l2_demuxer = {
 638     "video4linux2",
 639     NULL_IF_CONFIG_SMALL("video grab"),
 640     sizeof(struct video_data),
 641     NULL,
 642     v4l2_read_header,
 643     v4l2_read_packet,
 644     v4l2_read_close,
 645     .flags = AVFMT_NOFILE,
 646 };