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 AV_PIX_FMT_*
  11  *
  12  *
  13  * This file is part of Libav.
  14  *
  15  * Libav 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  * Libav 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 Libav; 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 "libavformat/internal.h"
  34 #include <unistd.h>
  35 #include <fcntl.h>
  36 #include <sys/ioctl.h>
  37 #include <sys/mman.h>
  38 #include <sys/time.h>
  39 #include <poll.h>
  40 #if HAVE_SYS_VIDEOIO_H
  41 #include <sys/videoio.h>
  42 #else
  43 #include <linux/videodev2.h>
  44 #endif
  45 #include "libavutil/atomic.h"
  46 #include "libavutil/avassert.h"
  47 #include "libavutil/imgutils.h"
  48 #include "libavutil/internal.h"
  49 #include "libavutil/log.h"
  50 #include "libavutil/opt.h"
  51 #include "libavutil/parseutils.h"
  52 #include "libavutil/pixdesc.h"
  53 #include "libavutil/avstring.h"
  54 #include "libavutil/mathematics.h"
  55
  56 static const int desired_video_buffers = 256;
  57
  58 #define V4L_ALLFORMATS  3
  59 #define V4L_RAWFORMATS  1
  60 #define V4L_COMPFORMATS 2
  61
  62 struct video_data {
  63     AVClass *class;
  64     int fd;
  65     int frame_format; /* V4L2_PIX_FMT_* */
  66     int width, height;
  67     int frame_size;
  68     int timeout;
  69     int interlaced;
  70     int top_field_first;
  71
  72     int buffers;
  73     volatile int buffers_queued;
  74     void **buf_start;
  75     unsigned int *buf_len;
  76     char *standard;
  77     int channel;
  78     char *video_size;   /**< String describing video size,
  79                              set by a private option. */
  80     char *pixel_format; /**< Set by a private option. */
  81     int list_format;    /**< Set by a private option. */
  82     char *framerate;    /**< Set by a private option. */
  83 };
  84
  85 struct buff_data {
  86     struct video_data *s;
  87     int index;
  88     int fd;
  89 };
  90
  91 struct fmt_map {
  92     enum AVPixelFormat ff_fmt;
  93     enum AVCodecID codec_id;
  94     uint32_t v4l2_fmt;
  95 };
  96
  97 static struct fmt_map fmt_conversion_table[] = {
  98     //ff_fmt           codec_id           v4l2_fmt
  99     { AV_PIX_FMT_YUV420P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV420  },
 100     { AV_PIX_FMT_YUV422P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV422P },
 101     { AV_PIX_FMT_YUYV422, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUYV    },
 102     { AV_PIX_FMT_UYVY422, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_UYVY    },
 103     { AV_PIX_FMT_YUV411P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV411P },
 104     { AV_PIX_FMT_YUV410P, AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_YUV410  },
 105     { AV_PIX_FMT_RGB555,  AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB555  },
 106     { AV_PIX_FMT_RGB565,  AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB565  },
 107     { AV_PIX_FMT_BGR24,   AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR24   },
 108     { AV_PIX_FMT_RGB24,   AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_RGB24   },
 109     { AV_PIX_FMT_BGRA,    AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_BGR32   },
 110     { AV_PIX_FMT_GRAY8,   AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_GREY    },
 111     { AV_PIX_FMT_NV12,    AV_CODEC_ID_RAWVIDEO, V4L2_PIX_FMT_NV12    },
 112     { AV_PIX_FMT_NONE,    AV_CODEC_ID_MJPEG,    V4L2_PIX_FMT_MJPEG   },
 113     { AV_PIX_FMT_NONE,    AV_CODEC_ID_MJPEG,    V4L2_PIX_FMT_JPEG    },
 114 #ifdef V4L2_PIX_FMT_H264
 115     { AV_PIX_FMT_NONE,    AV_CODEC_ID_H264,     V4L2_PIX_FMT_H264    },
 116 #endif
 117 };
 118
 119 static int device_open(AVFormatContext *ctx)
 120 {
 121     struct v4l2_capability cap;
 122     int fd;
 123     int res, err;
 124     int flags = O_RDWR;
 125     char errbuf[128];
 126
 127     if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
 128         flags |= O_NONBLOCK;
 129     }
 130
 131     fd = avpriv_open(ctx->filename, flags);
 132     if (fd < 0) {
 133         err = AVERROR(errno);
 134         av_strerror(err, errbuf, sizeof(errbuf));
 135
 136         av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s : %s\n",
 137                ctx->filename, errbuf);
 138
 139         return err;
 140     }
 141
 142     res = ioctl(fd, VIDIOC_QUERYCAP, &cap);
 143     if (res < 0) {
 144         err = AVERROR(errno);
 145         av_strerror(err, errbuf, sizeof(errbuf));
 146         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
 147                errbuf);
 148
 149         goto fail;
 150     }
 151
 152     av_log(ctx, AV_LOG_VERBOSE, "[%d]Capabilities: %x\n",
 153            fd, cap.capabilities);
 154
 155     if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
 156         av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
 157         err = AVERROR(ENODEV);
 158
 159         goto fail;
 160     }
 161
 162     if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
 163         av_log(ctx, AV_LOG_ERROR,
 164                "The device does not support the streaming I/O method.\n");
 165         err = AVERROR(ENOSYS);
 166
 167         goto fail;
 168     }
 169
 170     return fd;
 171
 172 fail:
 173     close(fd);
 174     return err;
 175 }
 176
 177 static int device_init(AVFormatContext *ctx, int *width, int *height,
 178                        uint32_t pix_fmt)
 179 {
 180     struct video_data *s = ctx->priv_data;
 181     int fd = s->fd;
 182     struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
 183     struct v4l2_pix_format *pix = &fmt.fmt.pix;
 184
 185     int res;
 186
 187     pix->width = *width;
 188     pix->height = *height;
 189     pix->pixelformat = pix_fmt;
 190     pix->field = V4L2_FIELD_ANY;
 191
 192     res = ioctl(fd, VIDIOC_S_FMT, &fmt);
 193
 194     if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
 195         av_log(ctx, AV_LOG_INFO,
 196                "The V4L2 driver changed the video from %dx%d to %dx%d\n",
 197                *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
 198         *width = fmt.fmt.pix.width;
 199         *height = fmt.fmt.pix.height;
 200     }
 201
 202     if (pix_fmt != fmt.fmt.pix.pixelformat) {
 203         av_log(ctx, AV_LOG_DEBUG,
 204                "The V4L2 driver changed the pixel format "
 205                "from 0x%08X to 0x%08X\n",
 206                pix_fmt, fmt.fmt.pix.pixelformat);
 207         res = -1;
 208     }
 209
 210     if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
 211         av_log(ctx, AV_LOG_DEBUG, "The V4L2 driver using the interlaced mode");
 212         s->interlaced = 1;
 213     }
 214
 215     return res;
 216 }
 217
 218 static int first_field(int fd)
 219 {
 220     int res;
 221     v4l2_std_id std;
 222
 223     res = ioctl(fd, VIDIOC_G_STD, &std);
 224     if (res < 0) {
 225         return 0;
 226     }
 227     if (std & V4L2_STD_NTSC) {
 228         return 0;
 229     }
 230
 231     return 1;
 232 }
 233
 234 static uint32_t fmt_ff2v4l(enum AVPixelFormat pix_fmt, enum AVCodecID codec_id)
 235 {
 236     int i;
 237
 238     for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
 239         if ((codec_id == AV_CODEC_ID_NONE ||
 240              fmt_conversion_table[i].codec_id == codec_id) &&
 241             (pix_fmt == AV_PIX_FMT_NONE ||
 242              fmt_conversion_table[i].ff_fmt == pix_fmt)) {
 243             return fmt_conversion_table[i].v4l2_fmt;
 244         }
 245     }
 246
 247     return 0;
 248 }
 249
 250 static enum AVPixelFormat fmt_v4l2ff(uint32_t v4l2_fmt, enum AVCodecID codec_id)
 251 {
 252     int i;
 253
 254     for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
 255         if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt &&
 256             fmt_conversion_table[i].codec_id == codec_id) {
 257             return fmt_conversion_table[i].ff_fmt;
 258         }
 259     }
 260
 261     return AV_PIX_FMT_NONE;
 262 }
 263
 264 static enum AVCodecID fmt_v4l2codec(uint32_t v4l2_fmt)
 265 {
 266     int i;
 267
 268     for (i = 0; i < FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
 269         if (fmt_conversion_table[i].v4l2_fmt == v4l2_fmt) {
 270             return fmt_conversion_table[i].codec_id;
 271         }
 272     }
 273
 274     return AV_CODEC_ID_NONE;
 275 }
 276
 277 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
 278 static void list_framesizes(AVFormatContext *ctx, int fd, uint32_t pixelformat)
 279 {
 280     struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
 281
 282     while(!ioctl(fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
 283         switch (vfse.type) {
 284         case V4L2_FRMSIZE_TYPE_DISCRETE:
 285             av_log(ctx, AV_LOG_INFO, " %ux%u",
 286                    vfse.discrete.width, vfse.discrete.height);
 287         break;
 288         case V4L2_FRMSIZE_TYPE_CONTINUOUS:
 289         case V4L2_FRMSIZE_TYPE_STEPWISE:
 290             av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
 291                    vfse.stepwise.min_width,
 292                    vfse.stepwise.max_width,
 293                    vfse.stepwise.step_width,
 294                    vfse.stepwise.min_height,
 295                    vfse.stepwise.max_height,
 296                    vfse.stepwise.step_height);
 297         }
 298         vfse.index++;
 299     }
 300 }
 301 #endif
 302
 303 static void list_formats(AVFormatContext *ctx, int fd, int type)
 304 {
 305     struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
 306
 307     while(!ioctl(fd, VIDIOC_ENUM_FMT, &vfd)) {
 308         enum AVCodecID codec_id = fmt_v4l2codec(vfd.pixelformat);
 309         enum AVPixelFormat pix_fmt = fmt_v4l2ff(vfd.pixelformat, codec_id);
 310
 311         vfd.index++;
 312
 313         if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
 314             type & V4L_RAWFORMATS) {
 315             const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
 316             av_log(ctx, AV_LOG_INFO, "R : %9s : %20s :",
 317                    fmt_name ? fmt_name : "Unsupported",
 318                    vfd.description);
 319         } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
 320                    type & V4L_COMPFORMATS) {
 321             const AVCodecDescriptor *desc = avcodec_descriptor_get(codec_id);
 322             av_log(ctx, AV_LOG_INFO, "C : %9s : %20s :",
 323                    desc ? desc->name : "Unsupported",
 324                    vfd.description);
 325         } else {
 326             continue;
 327         }
 328
 329 #ifdef V4L2_FMT_FLAG_EMULATED
 330         if (vfd.flags & V4L2_FMT_FLAG_EMULATED) {
 331             av_log(ctx, AV_LOG_WARNING, "%s", "Emulated");
 332             continue;
 333         }
 334 #endif
 335 #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
 336         list_framesizes(ctx, fd, vfd.pixelformat);
 337 #endif
 338         av_log(ctx, AV_LOG_INFO, "\n");
 339     }
 340 }
 341
 342 static int mmap_init(AVFormatContext *ctx)
 343 {
 344     int i, res;
 345     struct video_data *s = ctx->priv_data;
 346     struct v4l2_requestbuffers req = {
 347         .type   = V4L2_BUF_TYPE_VIDEO_CAPTURE,
 348         .count  = desired_video_buffers,
 349         .memory = V4L2_MEMORY_MMAP
 350     };
 351
 352     res = ioctl(s->fd, VIDIOC_REQBUFS, &req);
 353     if (res < 0) {
 354         res = AVERROR(errno);
 355         if (res == AVERROR(EINVAL)) {
 356             av_log(ctx, AV_LOG_ERROR, "Device does not support mmap\n");
 357         } else {
 358             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS)\n");
 359         }
 360
 361         return res;
 362     }
 363
 364     if (req.count < 2) {
 365         av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
 366
 367         return AVERROR(ENOMEM);
 368     }
 369     s->buffers = req.count;
 370     s->buf_start = av_malloc(sizeof(void *) * s->buffers);
 371     if (!s->buf_start) {
 372         av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
 373
 374         return AVERROR(ENOMEM);
 375     }
 376     s->buf_len = av_malloc(sizeof(unsigned int) * s->buffers);
 377     if (!s->buf_len) {
 378         av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
 379         av_free(s->buf_start);
 380
 381         return AVERROR(ENOMEM);
 382     }
 383
 384     for (i = 0; i < req.count; i++) {
 385         struct v4l2_buffer buf = {
 386             .type   = V4L2_BUF_TYPE_VIDEO_CAPTURE,
 387             .index  = i,
 388             .memory = V4L2_MEMORY_MMAP
 389         };
 390
 391         res = ioctl(s->fd, VIDIOC_QUERYBUF, &buf);
 392         if (res < 0) {
 393             res = AVERROR(errno);
 394             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF)\n");
 395
 396             return res;
 397         }
 398
 399         s->buf_len[i] = buf.length;
 400         if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
 401             av_log(ctx, AV_LOG_ERROR,
 402                    "Buffer len [%d] = %d != %d\n",
 403                    i, s->buf_len[i], s->frame_size);
 404
 405             return -1;
 406         }
 407         s->buf_start[i] = mmap(NULL, buf.length,
 408                                PROT_READ | PROT_WRITE, MAP_SHARED,
 409                                s->fd, buf.m.offset);
 410
 411         if (s->buf_start[i] == MAP_FAILED) {
 412             char errbuf[128];
 413             res = AVERROR(errno);
 414             av_strerror(res, errbuf, sizeof(errbuf));
 415             av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", errbuf);
 416
 417             return res;
 418         }
 419     }
 420
 421     return 0;
 422 }
 423
 424 #if FF_API_DESTRUCT_PACKET
 425 static void dummy_release_buffer(AVPacket *pkt)
 426 {
 427     av_assert0(0);
 428 }
 429 #endif
 430
 431 static void mmap_release_buffer(void *opaque, uint8_t *data)
 432 {
 433     struct v4l2_buffer buf = { 0 };
 434     int res, fd;
 435     struct buff_data *buf_descriptor = opaque;
 436     struct video_data *s = buf_descriptor->s;
 437     char errbuf[128];
 438
 439     buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 440     buf.memory = V4L2_MEMORY_MMAP;
 441     buf.index = buf_descriptor->index;
 442     fd = buf_descriptor->fd;
 443     av_free(buf_descriptor);
 444
 445     res = ioctl(fd, VIDIOC_QBUF, &buf);
 446     if (res < 0) {
 447         av_strerror(AVERROR(errno), errbuf, sizeof(errbuf));
 448         av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
 449                errbuf);
 450     }
 451     avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
 452 }
 453
 454 static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
 455 {
 456     struct video_data *s = ctx->priv_data;
 457     struct v4l2_buffer buf = {
 458         .type   = V4L2_BUF_TYPE_VIDEO_CAPTURE,
 459         .memory = V4L2_MEMORY_MMAP
 460     };
 461     struct pollfd p = { .fd = s->fd, .events = POLLIN };
 462     int res;
 463
 464     res = poll(&p, 1, s->timeout);
 465     if (res < 0)
 466         return AVERROR(errno);
 467
 468     if (!(p.revents & (POLLIN | POLLERR | POLLHUP)))
 469         return AVERROR(EAGAIN);
 470
 471     /* FIXME: Some special treatment might be needed in case of loss of signal... */
 472     while ((res = ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
 473     if (res < 0) {
 474         char errbuf[128];
 475         if (errno == EAGAIN) {
 476             pkt->size = 0;
 477
 478             return AVERROR(EAGAIN);
 479         }
 480         res = AVERROR(errno);
 481         av_strerror(res, errbuf, sizeof(errbuf));
 482         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n",
 483                errbuf);
 484
 485         return res;
 486     }
 487
 488     if (buf.index >= s->buffers) {
 489         av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
 490         return AVERROR(EINVAL);
 491     }
 492     avpriv_atomic_int_add_and_fetch(&s->buffers_queued, -1);
 493     // always keep at least one buffer queued
 494     av_assert0(avpriv_atomic_int_get(&s->buffers_queued) >= 1);
 495
 496     if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
 497         av_log(ctx, AV_LOG_ERROR,
 498                "The v4l2 frame is %d bytes, but %d bytes are expected\n",
 499                buf.bytesused, s->frame_size);
 500
 501         return AVERROR_INVALIDDATA;
 502     }
 503
 504     /* Image is at s->buff_start[buf.index] */
 505     if (avpriv_atomic_int_get(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
 506         /* when we start getting low on queued buffers, fall back on copying data */
 507         res = av_new_packet(pkt, buf.bytesused);
 508         if (res < 0) {
 509             av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
 510             return res;
 511         }
 512         memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
 513
 514         res = ioctl(s->fd, VIDIOC_QBUF, &buf);
 515         if (res < 0) {
 516             res = AVERROR(errno);
 517             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF)\n");
 518             av_free_packet(pkt);
 519             return res;
 520         }
 521         avpriv_atomic_int_add_and_fetch(&s->buffers_queued, 1);
 522     } else {
 523         struct buff_data *buf_descriptor;
 524
 525         pkt->data     = s->buf_start[buf.index];
 526         pkt->size     = buf.bytesused;
 527 #if FF_API_DESTRUCT_PACKET
 528 FF_DISABLE_DEPRECATION_WARNINGS
 529         pkt->destruct = dummy_release_buffer;
 530 FF_ENABLE_DEPRECATION_WARNINGS
 531 #endif
 532
 533         buf_descriptor = av_malloc(sizeof(struct buff_data));
 534         if (!buf_descriptor) {
 535             /* Something went wrong... Since av_malloc() failed, we cannot even
 536              * allocate a buffer for memcpying into it
 537              */
 538             av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
 539             res = ioctl(s->fd, VIDIOC_QBUF, &buf);
 540
 541             return AVERROR(ENOMEM);
 542         }
 543         buf_descriptor->fd    = s->fd;
 544         buf_descriptor->index = buf.index;
 545         buf_descriptor->s     = s;
 546
 547         pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
 548                                     buf_descriptor, 0);
 549         if (!pkt->buf) {
 550             av_freep(&buf_descriptor);
 551             return AVERROR(ENOMEM);
 552         }
 553     }
 554     pkt->pts = buf.timestamp.tv_sec * INT64_C(1000000) + buf.timestamp.tv_usec;
 555
 556     return s->buf_len[buf.index];
 557 }
 558
 559 static int mmap_start(AVFormatContext *ctx)
 560 {
 561     struct video_data *s = ctx->priv_data;
 562     enum v4l2_buf_type type;
 563     int i, res, err;
 564     char errbuf[128];
 565
 566     for (i = 0; i < s->buffers; i++) {
 567         struct v4l2_buffer buf = {
 568             .type   = V4L2_BUF_TYPE_VIDEO_CAPTURE,
 569             .index  = i,
 570             .memory = V4L2_MEMORY_MMAP
 571         };
 572
 573         res = ioctl(s->fd, VIDIOC_QBUF, &buf);
 574         if (res < 0) {
 575             err = AVERROR(errno);
 576             av_strerror(err, errbuf, sizeof(errbuf));
 577             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
 578                    errbuf);
 579
 580             return err;
 581         }
 582     }
 583     s->buffers_queued = s->buffers;
 584
 585     type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 586     res = ioctl(s->fd, VIDIOC_STREAMON, &type);
 587     if (res < 0) {
 588         err = AVERROR(errno);
 589         av_strerror(err, errbuf, sizeof(errbuf));
 590         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
 591                errbuf);
 592
 593         return err;
 594     }
 595
 596     return 0;
 597 }
 598
 599 static void mmap_close(struct video_data *s)
 600 {
 601     enum v4l2_buf_type type;
 602     int i;
 603
 604     type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 605     /* We do not check for the result, because we could
 606      * not do anything about it anyway...
 607      */
 608     ioctl(s->fd, VIDIOC_STREAMOFF, &type);
 609     for (i = 0; i < s->buffers; i++) {
 610         munmap(s->buf_start[i], s->buf_len[i]);
 611     }
 612     av_free(s->buf_start);
 613     av_free(s->buf_len);
 614 }
 615
 616 static int v4l2_set_parameters(AVFormatContext *s1)
 617 {
 618     struct video_data *s = s1->priv_data;
 619     struct v4l2_input input = { 0 };
 620     struct v4l2_standard standard = { 0 };
 621     struct v4l2_streamparm streamparm = { 0 };
 622     struct v4l2_fract *tpf = &streamparm.parm.capture.timeperframe;
 623     AVRational framerate_q = { 0 };
 624     int i, ret;
 625
 626     streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 627
 628     if (s->framerate &&
 629         (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
 630         av_log(s1, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
 631                s->framerate);
 632         return ret;
 633     }
 634
 635     /* set tv video input */
 636     input.index = s->channel;
 637     if (ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
 638         av_log(s1, AV_LOG_ERROR, "The V4L2 driver ioctl enum input failed:\n");
 639         return AVERROR(EIO);
 640     }
 641
 642     av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set input_id: %d, input: %s\n",
 643             s->channel, input.name);
 644     if (ioctl(s->fd, VIDIOC_S_INPUT, &input.index) < 0) {
 645         av_log(s1, AV_LOG_ERROR,
 646                "The V4L2 driver ioctl set input(%d) failed\n",
 647                 s->channel);
 648         return AVERROR(EIO);
 649     }
 650
 651     if (s->standard) {
 652         av_log(s1, AV_LOG_DEBUG, "The V4L2 driver set standard: %s\n",
 653                s->standard);
 654         /* set tv standard */
 655         for(i=0;;i++) {
 656             standard.index = i;
 657             if (ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
 658                 av_log(s1, AV_LOG_ERROR,
 659                        "The V4L2 driver ioctl set standard(%s) failed\n",
 660                        s->standard);
 661                 return AVERROR(EIO);
 662             }
 663
 664             if (!av_strcasecmp(standard.name, s->standard)) {
 665                 break;
 666             }
 667         }
 668
 669         av_log(s1, AV_LOG_DEBUG,
 670                "The V4L2 driver set standard: %s, id: %"PRIu64"\n",
 671                s->standard, (uint64_t)standard.id);
 672         if (ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
 673             av_log(s1, AV_LOG_ERROR,
 674                    "The V4L2 driver ioctl set standard(%s) failed\n",
 675                    s->standard);
 676             return AVERROR(EIO);
 677         }
 678     }
 679
 680     if (framerate_q.num && framerate_q.den) {
 681         av_log(s1, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
 682                framerate_q.den, framerate_q.num);
 683         tpf->numerator   = framerate_q.den;
 684         tpf->denominator = framerate_q.num;
 685
 686         if (ioctl(s->fd, VIDIOC_S_PARM, &streamparm) != 0) {
 687             av_log(s1, AV_LOG_ERROR,
 688                    "ioctl set time per frame(%d/%d) failed\n",
 689                    framerate_q.den, framerate_q.num);
 690             return AVERROR(EIO);
 691         }
 692
 693         if (framerate_q.num != tpf->denominator ||
 694             framerate_q.den != tpf->numerator) {
 695             av_log(s1, AV_LOG_INFO,
 696                    "The driver changed the time per frame from "
 697                    "%d/%d to %d/%d\n",
 698                    framerate_q.den, framerate_q.num,
 699                    tpf->numerator, tpf->denominator);
 700         }
 701     } else {
 702         if (ioctl(s->fd, VIDIOC_G_PARM, &streamparm) != 0) {
 703             char errbuf[128];
 704             ret = AVERROR(errno);
 705             av_strerror(ret, errbuf, sizeof(errbuf));
 706             av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_PARM): %s\n",
 707                    errbuf);
 708             return ret;
 709         }
 710     }
 711     s1->streams[0]->avg_frame_rate.num = tpf->denominator;
 712     s1->streams[0]->avg_frame_rate.den = tpf->numerator;
 713
 714     s->timeout = 100 +
 715         av_rescale_q(1, s1->streams[0]->avg_frame_rate,
 716                         (AVRational){1, 1000});
 717
 718     return 0;
 719 }
 720
 721 static uint32_t device_try_init(AVFormatContext *s1,
 722                                 enum AVPixelFormat pix_fmt,
 723                                 int *width,
 724                                 int *height,
 725                                 enum AVCodecID *codec_id)
 726 {
 727     uint32_t desired_format = fmt_ff2v4l(pix_fmt, s1->video_codec_id);
 728
 729     if (desired_format == 0 ||
 730         device_init(s1, width, height, desired_format) < 0) {
 731         int i;
 732
 733         desired_format = 0;
 734         for (i = 0; i<FF_ARRAY_ELEMS(fmt_conversion_table); i++) {
 735             if (s1->video_codec_id == AV_CODEC_ID_NONE ||
 736                 fmt_conversion_table[i].codec_id == s1->video_codec_id) {
 737                 desired_format = fmt_conversion_table[i].v4l2_fmt;
 738                 if (device_init(s1, width, height, desired_format) >= 0) {
 739                     break;
 740                 }
 741                 desired_format = 0;
 742             }
 743         }
 744     }
 745
 746     if (desired_format != 0) {
 747         *codec_id = fmt_v4l2codec(desired_format);
 748         assert(*codec_id != AV_CODEC_ID_NONE);
 749     }
 750
 751     return desired_format;
 752 }
 753
 754 static int v4l2_read_header(AVFormatContext *s1)
 755 {
 756     struct video_data *s = s1->priv_data;
 757     AVStream *st;
 758     int res = 0;
 759     uint32_t desired_format;
 760     enum AVCodecID codec_id;
 761     enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
 762
 763     st = avformat_new_stream(s1, NULL);
 764     if (!st)
 765         return AVERROR(ENOMEM);
 766
 767     s->fd = device_open(s1);
 768     if (s->fd < 0)
 769         return s->fd;
 770
 771     if (s->list_format) {
 772         list_formats(s1, s->fd, s->list_format);
 773         return AVERROR_EXIT;
 774     }
 775
 776     avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
 777
 778     if (s->video_size &&
 779         (res = av_parse_video_size(&s->width, &s->height, s->video_size)) < 0) {
 780         av_log(s1, AV_LOG_ERROR, "Could not parse video size '%s'.\n",
 781                s->video_size);
 782         return res;
 783     }
 784
 785     if (s->pixel_format) {
 786         AVCodec *codec = avcodec_find_decoder_by_name(s->pixel_format);
 787
 788         if (codec) {
 789             s1->video_codec_id = codec->id;
 790             st->need_parsing   = AVSTREAM_PARSE_HEADERS;
 791         }
 792
 793         pix_fmt = av_get_pix_fmt(s->pixel_format);
 794
 795         if (pix_fmt == AV_PIX_FMT_NONE && !codec) {
 796             av_log(s1, AV_LOG_ERROR, "No such input format: %s.\n",
 797                    s->pixel_format);
 798
 799             return AVERROR(EINVAL);
 800         }
 801     }
 802
 803     if (!s->width && !s->height) {
 804         struct v4l2_format fmt;
 805
 806         av_log(s1, AV_LOG_VERBOSE,
 807                "Querying the device for the current frame size\n");
 808         fmt.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
 809         if (ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
 810             char errbuf[128];
 811             res = AVERROR(errno);
 812             av_strerror(res, errbuf, sizeof(errbuf));
 813             av_log(s1, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
 814                    errbuf);
 815             return res;
 816         }
 817
 818         s->width  = fmt.fmt.pix.width;
 819         s->height = fmt.fmt.pix.height;
 820         av_log(s1, AV_LOG_VERBOSE,
 821                "Setting frame size to %dx%d\n", s->width, s->height);
 822     }
 823
 824     desired_format = device_try_init(s1, pix_fmt, &s->width, &s->height,
 825                                      &codec_id);
 826     if (desired_format == 0) {
 827         av_log(s1, AV_LOG_ERROR, "Cannot find a proper format for "
 828                "codec_id %d, pix_fmt %d.\n", s1->video_codec_id, pix_fmt);
 829         close(s->fd);
 830
 831         return AVERROR(EIO);
 832     }
 833
 834     if ((res = av_image_check_size(s->width, s->height, 0, s1) < 0))
 835         return res;
 836
 837     s->frame_format = desired_format;
 838
 839     if ((res = v4l2_set_parameters(s1) < 0))
 840         return res;
 841
 842     st->codec->pix_fmt = fmt_v4l2ff(desired_format, codec_id);
 843     s->frame_size =
 844         avpicture_get_size(st->codec->pix_fmt, s->width, s->height);
 845
 846     if ((res = mmap_init(s1)) ||
 847         (res = mmap_start(s1)) < 0) {
 848         close(s->fd);
 849         return res;
 850     }
 851
 852     s->top_field_first = first_field(s->fd);
 853
 854     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
 855     st->codec->codec_id = codec_id;
 856     if (codec_id == AV_CODEC_ID_RAWVIDEO)
 857         st->codec->codec_tag =
 858             avcodec_pix_fmt_to_codec_tag(st->codec->pix_fmt);
 859     st->codec->width = s->width;
 860     st->codec->height = s->height;
 861     st->codec->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
 862
 863     return 0;
 864 }
 865
 866 static int v4l2_read_packet(AVFormatContext *s1, AVPacket *pkt)
 867 {
 868     struct video_data *s = s1->priv_data;
 869     AVFrame *frame = s1->streams[0]->codec->coded_frame;
 870     int res;
 871
 872     av_init_packet(pkt);
 873     if ((res = mmap_read_frame(s1, pkt)) < 0) {
 874         return res;
 875     }
 876
 877     if (frame && s->interlaced) {
 878         frame->interlaced_frame = 1;
 879         frame->top_field_first = s->top_field_first;
 880     }
 881
 882     return pkt->size;
 883 }
 884
 885 static int v4l2_read_close(AVFormatContext *s1)
 886 {
 887     struct video_data *s = s1->priv_data;
 888
 889     if (avpriv_atomic_int_get(&s->buffers_queued) != s->buffers)
 890         av_log(s1, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
 891                "close.\n");
 892
 893     mmap_close(s);
 894
 895     close(s->fd);
 896     return 0;
 897 }
 898
 899 #define OFFSET(x) offsetof(struct video_data, x)
 900 #define DEC AV_OPT_FLAG_DECODING_PARAM
 901 static const AVOption options[] = {
 902     { "standard",     "TV standard, used only by analog frame grabber",            OFFSET(standard),     AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0,       DEC },
 903     { "channel",      "TV channel, used only by frame grabber",                    OFFSET(channel),      AV_OPT_TYPE_INT,    {.i64 = 0 },    0, INT_MAX, DEC },
 904     { "video_size",   "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size),   AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
 905     { "pixel_format", "Preferred pixel format",                                    OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
 906     { "input_format", "Preferred pixel format (for raw video) or codec name",      OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
 907     { "framerate",    "",                                                          OFFSET(framerate),    AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
 908     { "list_formats", "List available formats and exit",                           OFFSET(list_format),  AV_OPT_TYPE_INT,    {.i64 = 0 },  0, INT_MAX, DEC, "list_formats" },
 909     { "all",          "Show all available formats",                                OFFSET(list_format),  AV_OPT_TYPE_CONST,  {.i64 = V4L_ALLFORMATS  },    0, INT_MAX, DEC, "list_formats" },
 910     { "raw",          "Show only non-compressed formats",                          OFFSET(list_format),  AV_OPT_TYPE_CONST,  {.i64 = V4L_RAWFORMATS  },    0, INT_MAX, DEC, "list_formats" },
 911     { "compressed",   "Show only compressed formats",                              OFFSET(list_format),  AV_OPT_TYPE_CONST,  {.i64 = V4L_COMPFORMATS },    0, INT_MAX, DEC, "list_formats" },
 912     { NULL },
 913 };
 914
 915 static const AVClass v4l2_class = {
 916     .class_name = "V4L2 indev",
 917     .item_name  = av_default_item_name,
 918     .option     = options,
 919     .version    = LIBAVUTIL_VERSION_INT,
 920 };
 921
 922 AVInputFormat ff_v4l2_demuxer = {
 923     .name           = "video4linux2",
 924     .long_name      = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
 925     .priv_data_size = sizeof(struct video_data),
 926     .read_header    = v4l2_read_header,
 927     .read_packet    = v4l2_read_packet,
 928     .read_close     = v4l2_read_close,
 929     .flags          = AVFMT_NOFILE,
 930     .priv_class     = &v4l2_class,
 931 };