libavformat/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 library is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU Lesser General Public
  15  * License as published by the Free Software Foundation; either
  16  * version 2 of the License, or (at your option) any later version.
  17  *
  18  * This library is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  21  * Lesser General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU Lesser General Public
  24  * License along with this library; if not, write to the Free Software
  25  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  26  */
  27 #include "avformat.h"
  28 #include <unistd.h>
  29 #include <fcntl.h>
  30 #include <sys/ioctl.h>
  31 #include <sys/mman.h>
  32 #include <sys/time.h>
  33 #define _LINUX_TIME_H 1
  34 #include <linux/videodev.h>
  35 #include <time.h>
  36
  37 static const int desired_video_buffers = 256;
  38
  39 enum io_method {
  40     io_read,
  41     io_mmap,
  42     io_userptr
  43 };
  44
  45 struct video_data {
  46     int fd;
  47     int frame_format; /* V4L2_PIX_FMT_* */
  48     enum io_method io_method;
  49     int width, height;
  50     int frame_rate;
  51     int frame_rate_base;
  52     int frame_size;
  53     int top_field_first;
  54
  55     int buffers;
  56     void **buf_start;
  57     unsigned int *buf_len;
  58 };
  59
  60 struct fmt_map {
  61     enum PixelFormat ff_fmt;
  62     int32_t v4l2_fmt;
  63 };
  64
  65 static struct fmt_map fmt_conversion_table[] = {
  66     {
  67         .ff_fmt = PIX_FMT_YUV420P,
  68         .v4l2_fmt = V4L2_PIX_FMT_YUV420,
  69     },
  70     {
  71         .ff_fmt = PIX_FMT_YUV422P,
  72         .v4l2_fmt = V4L2_PIX_FMT_YUV422P,
  73     },
  74     {
  75         .ff_fmt = PIX_FMT_YUV422,
  76         .v4l2_fmt = V4L2_PIX_FMT_YUYV,
  77     },
  78     {
  79         .ff_fmt = PIX_FMT_UYVY422,
  80         .v4l2_fmt = V4L2_PIX_FMT_UYVY,
  81     },
  82     {
  83         .ff_fmt = PIX_FMT_YUV411P,
  84         .v4l2_fmt = V4L2_PIX_FMT_YUV411P,
  85     },
  86     {
  87         .ff_fmt = PIX_FMT_YUV410P,
  88         .v4l2_fmt = V4L2_PIX_FMT_YUV410,
  89     },
  90     {
  91         .ff_fmt = PIX_FMT_BGR24,
  92         .v4l2_fmt = V4L2_PIX_FMT_BGR24,
  93     },
  94     {
  95         .ff_fmt = PIX_FMT_RGB24,
  96         .v4l2_fmt = V4L2_PIX_FMT_RGB24,
  97     },
  98     /*
  99     {
 100         .ff_fmt = PIX_FMT_RGBA32,
 101         .v4l2_fmt = V4L2_PIX_FMT_BGR32,
 102     },
 103     */
 104     {
 105         .ff_fmt = PIX_FMT_GRAY8,
 106         .v4l2_fmt = V4L2_PIX_FMT_GREY,
 107     },
 108 };
 109
 110 static int device_open(const char *devname, uint32_t *capabilities)
 111 {
 112     struct v4l2_capability cap;
 113     int fd;
 114     int res;
 115
 116     fd = open(devname, O_RDWR /*| O_NONBLOCK*/, 0);
 117     if (fd < 0) {
 118         av_log(NULL, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
 119                  devname, strerror(errno));
 120
 121         return -1;
 122     }
 123
 124     res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
 125     if (res < 0) {
 126         av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
 127                  strerror(errno));
 128
 129         return -1;
 130     }
 131     if ((cap.capabilities & V4L2_CAP_VIDEO_CAPTURE) == 0) {
 132         av_log(NULL, AV_LOG_ERROR, "Not a video capture device\n");
 133
 134         return -1;
 135     }
 136     *capabilities = cap.capabilities;
 137
 138     return fd;
 139 }
 140
 141 static int device_init(int fd, int width, int height, int pix_fmt)
 142 {
 143     struct v4l2_format fmt;
 144
 145     memset(&fmt, 0, sizeof(struct v4l2_format));
 146     fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 147     fmt.fmt.pix.width = width;
 148     fmt.fmt.pix.height = height;
 149     fmt.fmt.pix.pixelformat = pix_fmt;
 150     fmt.fmt.pix.field = V4L2_FIELD_INTERLACED;
 151     return ioctl (fd, VIDIOC_S_FMT, &fmt);
 152 }
 153
 154 static int first_field(int fd)
 155 {
 156     int res;
 157     v4l2_std_id std;
 158
 159     res = ioctl(fd, VIDIOC_G_STD, &std);
 160     if (res < 0) {
 161         return 0;
 162     }
 163     if (std & V4L2_STD_NTSC) {
 164         return 0;
 165     }
 166
 167     return 1;
 168 }
 169
 170 static uint32_t fmt_ff2v4l(enum PixelFormat pix_fmt)
 171 {
 172     int i;
 173
 174     for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
 175         if (fmt_conversion_table[i].ff_fmt == pix_fmt) {
 176             return fmt_conversion_table[i].v4l2_fmt;
 177         }
 178     }
 179
 180     return 0;
 181 }
 182
 183 static enum PixelFormat fmt_v4l2ff(uint32_t pix_fmt)
 184 {
 185     int i;
 186
 187     for (i = 0; i < sizeof(fmt_conversion_table) / sizeof(struct fmt_map); i++) {
 188         if (fmt_conversion_table[i].v4l2_fmt == pix_fmt) {
 189             return fmt_conversion_table[i].ff_fmt;
 190         }
 191     }
 192
 193     return -1;
 194 }
 195
 196 static int mmap_init(struct video_data *s)
 197 {
 198     struct v4l2_requestbuffers req;
 199     int i, res;
 200
 201     memset(&req, 0, sizeof(struct v4l2_requestbuffers));
 202     req.count = desired_video_buffers;
 203     req.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 204     req.memory = V4L2_MEMORY_MMAP;
 205     res = ioctl (s->fd, VIDIOC_REQBUFS, &req);
 206     if (res < 0) {
 207         if (errno == EINVAL) {
 208             av_log(NULL, AV_LOG_ERROR, "Device does not support mmap\n");
 209         } else {
 210             av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
 211         }
 212
 213         return -1;
 214     }
 215
 216     if (req.count < 2) {
 217         av_log(NULL, AV_LOG_ERROR, "Insufficient buffer memory\n");
 218
 219         return -1;
 220     }
 221     s->buffers = req.count;
 222     s->buf_start = av_malloc(sizeof(void *) * s->buffers);
 223     if (s->buf_start == NULL) {
 224         av_log(NULL, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
 225
 226         return -1;
 227     }
 228     s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
 229     if (s->buf_len == NULL) {
 230         av_log(NULL, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
 231         av_free(s->buf_start);
 232
 233         return -1;
 234     }
 235
 236     for (i = 0; i < req.count; i++) {
 237         struct v4l2_buffer buf;
 238
 239         memset(&buf, 0, sizeof(struct v4l2_buffer));
 240         buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 241         buf.memory = V4L2_MEMORY_MMAP;
 242         buf.index = i;
 243         res = ioctl (s->fd, VIDIOC_QUERYBUF, &buf);
 244         if (res < 0) {
 245             av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
 246
 247             return -1;
 248         }
 249
 250         s->buf_len[i] = buf.length;
 251         if (s->buf_len[i] < s->frame_size) {
 252             av_log(NULL, AV_LOG_ERROR, "Buffer len [%d] = %d != %d\n", i, s->buf_len[i], s->frame_size);
 253
 254             return -1;
 255         }
 256         s->buf_start[i] = mmap (NULL, buf.length,
 257                         PROT_READ | PROT_WRITE, MAP_SHARED, s->fd, buf.m.offset);
 258         if (s->buf_start[i] == MAP_FAILED) {
 259             av_log(NULL, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
 260
 261             return -1;
 262         }
 263     }
 264
 265     return 0;
 266 }
 267
 268 static int read_init(struct video_data *s)
 269 {
 270     return -1;
 271 }
 272
 273 static int mmap_read_frame(struct video_data *s, void *frame, int64_t *ts)
 274 {
 275     struct v4l2_buffer buf;
 276     int res;
 277
 278     memset(&buf, 0, sizeof(struct v4l2_buffer));
 279     buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 280     buf.memory = V4L2_MEMORY_MMAP;
 281
 282     /* FIXME: Some special treatment might be needed in case of loss of signal... */
 283     while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 &&
 284            ((errno == EAGAIN) || (errno == EINTR)));
 285     if (res < 0) {
 286         av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n", strerror(errno));
 287
 288         return -1;
 289     }
 290     assert (buf.index < s->buffers);
 291     assert(buf.bytesused == s->frame_size);
 292     /* Image is at s->buff_start[buf.index] */
 293     memcpy(frame, s->buf_start[buf.index], buf.bytesused);
 294     *ts = buf.timestamp.tv_sec * int64_t_C(1000000) + buf.timestamp.tv_usec;
 295
 296     res = ioctl (s->fd, VIDIOC_QBUF, &buf);
 297     if (res < 0) {
 298         av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
 299
 300         return -1;
 301     }
 302
 303     return s->buf_len[buf.index];
 304 }
 305
 306 static int read_frame(struct video_data *s, void *frame, int64_t *ts)
 307 {
 308     return -1;
 309 }
 310
 311 static int mmap_start(struct video_data *s)
 312 {
 313     enum v4l2_buf_type type;
 314     int i, res;
 315
 316     for (i = 0; i < s->buffers; i++) {
 317         struct v4l2_buffer buf;
 318
 319         memset(&buf, 0, sizeof(struct v4l2_buffer));
 320         buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 321         buf.memory = V4L2_MEMORY_MMAP;
 322         buf.index  = i;
 323
 324         res = ioctl (s->fd, VIDIOC_QBUF, &buf);
 325         if (res < 0) {
 326             av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", strerror(errno));
 327
 328             return -1;
 329         }
 330     }
 331
 332     type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 333     res = ioctl (s->fd, VIDIOC_STREAMON, &type);
 334     if (res < 0) {
 335         av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n", strerror(errno));
 336
 337         return -1;
 338     }
 339
 340     return 0;
 341 }
 342
 343 static void mmap_close(struct video_data *s)
 344 {
 345     enum v4l2_buf_type type;
 346     int i;
 347
 348     type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 349     /* We do not check for the result, because we could
 350      * not do anything about it anyway...
 351      */
 352     ioctl(s->fd, VIDIOC_STREAMOFF, &type);
 353     for (i = 0; i < s->buffers; i++) {
 354         munmap(s->buf_start[i], s->buf_len[i]);
 355     }
 356     av_free(s->buf_start);
 357     av_free(s->buf_len);
 358 }
 359
 360 static int v4l2_read_header(AVFormatContext *s1, AVFormatParameters *ap)
 361 {
 362     struct video_data *s = s1->priv_data;
 363     AVStream *st;
 364     int width, height;
 365     int res, frame_rate, frame_rate_base;
 366     uint32_t desired_format, capabilities;
 367     const char *video_device;
 368
 369     if (!ap || ap->width <= 0 || ap->height <= 0 || ap->time_base.den <= 0) {
 370         av_log(s1, AV_LOG_ERROR, "Missing/Wrong parameters\n");
 371
 372         return -1;
 373     }
 374
 375     width = ap->width;
 376     height = ap->height;
 377     frame_rate = ap->time_base.den;
 378     frame_rate_base = ap->time_base.num;
 379
 380     if((unsigned)width > 32767 || (unsigned)height > 32767) {
 381         av_log(s1, AV_LOG_ERROR, "Wrong size %dx%d\n", width, height);
 382
 383         return -1;
 384     }
 385
 386     st = av_new_stream(s1, 0);
 387     if (!st) {
 388         return -ENOMEM;
 389     }
 390     av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
 391
 392     s->width = width;
 393     s->height = height;
 394     s->frame_rate      = frame_rate;
 395     s->frame_rate_base = frame_rate_base;
 396
 397     video_device = ap->device;
 398     if (!video_device) {
 399         video_device = "/dev/video";
 400     }
 401     capabilities = 0;
 402     s->fd = device_open(video_device, &capabilities);
 403     if (s->fd < 0) {
 404         av_free(st);
 405
 406         return AVERROR_IO;
 407     }
 408     av_log(s1, AV_LOG_ERROR, "[%d]Capabilities: %x\n", s->fd, capabilities);
 409
 410     desired_format = fmt_ff2v4l(ap->pix_fmt);
 411     if (desired_format == 0 || (device_init(s->fd, width, height, desired_format) < 0)) {
 412         int i, done;
 413
 414         done = 0; i = 0;
 415         while (!done) {
 416             desired_format = fmt_conversion_table[i].v4l2_fmt;
 417             if (device_init(s->fd, width, height, desired_format) < 0) {
 418                 desired_format = 0;
 419                 i++;
 420             } else {
 421                done = 1;
 422             }
 423             if (i == sizeof(fmt_conversion_table) / sizeof(struct fmt_map)) {
 424                done = 1;
 425             }
 426         }
 427     }
 428     if (desired_format == 0) {
 429         av_log(s1, AV_LOG_ERROR, "Cannot find a proper format.\n");
 430         close(s->fd);
 431         av_free(st);
 432
 433         return AVERROR_IO;
 434     }
 435     s->frame_format = desired_format;
 436
 437     st->codec->pix_fmt = fmt_v4l2ff(desired_format);
 438     s->frame_size = avpicture_get_size(st->codec->pix_fmt, width, height);
 439     if (capabilities & V4L2_CAP_STREAMING) {
 440         s->io_method = io_mmap;
 441         res = mmap_init(s);
 442         res = mmap_start(s);
 443     } else {
 444         s->io_method = io_read;
 445         res = read_init(s);
 446     }
 447     if (res < 0) {
 448         close(s->fd);
 449         av_free(st);
 450
 451         return AVERROR_IO;
 452     }
 453     s->top_field_first = first_field(s->fd);
 454
 455     st->codec->codec_type = CODEC_TYPE_VIDEO;
 456     st->codec->codec_id = CODEC_ID_RAWVIDEO;
 457     st->codec->width = width;
 458     st->codec->height = height;
 459     st->codec->time_base.den = frame_rate;
 460     st->codec->time_base.num = frame_rate_base;
 461     st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
 462
 463     return 0;
 464 }
 465
 466 static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
 467 {
 468     struct video_data *s = s1->priv_data;
 469     int res;
 470
 471     if (av_new_packet(pkt, s->frame_size) < 0)
 472         return AVERROR_IO;
 473
 474     if (s->io_method == io_mmap) {
 475         res = mmap_read_frame(s, pkt->data, &pkt->pts);
 476     } else if (s->io_method == io_read) {
 477         res = read_frame(s, pkt->data, &pkt->pts);
 478     } else {
 479         return AVERROR_IO;
 480     }
 481     if (res < 0) {
 482         return AVERROR_IO;
 483     }
 484
 485     if (s1->streams[0]->codec->coded_frame) {
 486         s1->streams[0]->codec->coded_frame->interlaced_frame = 1;
 487         s1->streams[0]->codec->coded_frame->top_field_first = s->top_field_first;
 488     }
 489
 490     return s->frame_size;
 491 }
 492
 493 static int v4l2_read_close(AVFormatContext *s1)
 494 {
 495     struct video_data *s = s1->priv_data;
 496
 497     if (s->io_method == io_mmap) {
 498         mmap_close(s);
 499     }
 500
 501     close(s->fd);
 502     return 0;
 503 }
 504
 505 static AVInputFormat v4l2_format = {
 506     "video4linux2",
 507     "video grab",
 508     sizeof(struct video_data),
 509     NULL,
 510     v4l2_read_header,
 511     v4l2_read_packet,
 512     v4l2_read_close,
 513     .flags = AVFMT_NOFILE,
 514 };
 515
 516 int v4l2_init(void)
 517 {
 518     av_register_input_format(&v4l2_format);
 519     return 0;
 520 }