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