LCOV - code coverage report
Current view: top level - libavdevice - v4l2.c (source / functions) Hit Total Coverage
Test: coverage.info Lines: 3 543 0.6 %
Date: 2017-12-18 06:23:41 Functions: 1 23 4.3 %

          Line data    Source code
       1             : /*
       2             :  * Copyright (c) 2000,2001 Fabrice Bellard
       3             :  * Copyright (c) 2006 Luca Abeni
       4             :  *
       5             :  * This file is part of FFmpeg.
       6             :  *
       7             :  * FFmpeg is free software; you can redistribute it and/or
       8             :  * modify it under the terms of the GNU Lesser General Public
       9             :  * License as published by the Free Software Foundation; either
      10             :  * version 2.1 of the License, or (at your option) any later version.
      11             :  *
      12             :  * FFmpeg is distributed in the hope that it will be useful,
      13             :  * but WITHOUT ANY WARRANTY; without even the implied warranty of
      14             :  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      15             :  * Lesser General Public License for more details.
      16             :  *
      17             :  * You should have received a copy of the GNU Lesser General Public
      18             :  * License along with FFmpeg; if not, write to the Free Software
      19             :  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
      20             :  */
      21             : 
      22             : /**
      23             :  * @file
      24             :  * Video4Linux2 grab interface
      25             :  *
      26             :  * Part of this file is based on the V4L2 video capture example
      27             :  * (http://linuxtv.org/downloads/v4l-dvb-apis/capture-example.html)
      28             :  *
      29             :  * Thanks to Michael Niedermayer for providing the mapping between
      30             :  * V4L2_PIX_FMT_* and AV_PIX_FMT_*
      31             :  */
      32             : 
      33             : #include <stdatomic.h>
      34             : 
      35             : #include "v4l2-common.h"
      36             : #include <dirent.h>
      37             : 
      38             : #if CONFIG_LIBV4L2
      39             : #include <libv4l2.h>
      40             : #endif
      41             : 
      42             : static const int desired_video_buffers = 256;
      43             : 
      44             : #define V4L_ALLFORMATS  3
      45             : #define V4L_RAWFORMATS  1
      46             : #define V4L_COMPFORMATS 2
      47             : 
      48             : /**
      49             :  * Return timestamps to the user exactly as returned by the kernel
      50             :  */
      51             : #define V4L_TS_DEFAULT  0
      52             : /**
      53             :  * Autodetect the kind of timestamps returned by the kernel and convert to
      54             :  * absolute (wall clock) timestamps.
      55             :  */
      56             : #define V4L_TS_ABS      1
      57             : /**
      58             :  * Assume kernel timestamps are from the monotonic clock and convert to
      59             :  * absolute timestamps.
      60             :  */
      61             : #define V4L_TS_MONO2ABS 2
      62             : 
      63             : /**
      64             :  * Once the kind of timestamps returned by the kernel have been detected,
      65             :  * the value of the timefilter (NULL or not) determines whether a conversion
      66             :  * takes place.
      67             :  */
      68             : #define V4L_TS_CONVERT_READY V4L_TS_DEFAULT
      69             : 
      70             : struct video_data {
      71             :     AVClass *class;
      72             :     int fd;
      73             :     int pixelformat; /* V4L2_PIX_FMT_* */
      74             :     int width, height;
      75             :     int frame_size;
      76             :     int interlaced;
      77             :     int top_field_first;
      78             :     int ts_mode;
      79             :     TimeFilter *timefilter;
      80             :     int64_t last_time_m;
      81             : 
      82             :     int buffers;
      83             :     atomic_int buffers_queued;
      84             :     void **buf_start;
      85             :     unsigned int *buf_len;
      86             :     char *standard;
      87             :     v4l2_std_id std_id;
      88             :     int channel;
      89             :     char *pixel_format; /**< Set by a private option. */
      90             :     int list_format;    /**< Set by a private option. */
      91             :     int list_standard;  /**< Set by a private option. */
      92             :     char *framerate;    /**< Set by a private option. */
      93             : 
      94             :     int use_libv4l2;
      95             :     int (*open_f)(const char *file, int oflag, ...);
      96             :     int (*close_f)(int fd);
      97             :     int (*dup_f)(int fd);
      98             :     int (*ioctl_f)(int fd, unsigned long int request, ...);
      99             :     ssize_t (*read_f)(int fd, void *buffer, size_t n);
     100             :     void *(*mmap_f)(void *start, size_t length, int prot, int flags, int fd, int64_t offset);
     101             :     int (*munmap_f)(void *_start, size_t length);
     102             : };
     103             : 
     104             : struct buff_data {
     105             :     struct video_data *s;
     106             :     int index;
     107             : };
     108             : 
     109           0 : static int device_open(AVFormatContext *ctx)
     110             : {
     111           0 :     struct video_data *s = ctx->priv_data;
     112             :     struct v4l2_capability cap;
     113             :     int fd;
     114             :     int err;
     115           0 :     int flags = O_RDWR;
     116             : 
     117             : #define SET_WRAPPERS(prefix) do {       \
     118             :     s->open_f   = prefix ## open;       \
     119             :     s->close_f  = prefix ## close;      \
     120             :     s->dup_f    = prefix ## dup;        \
     121             :     s->ioctl_f  = prefix ## ioctl;      \
     122             :     s->read_f   = prefix ## read;       \
     123             :     s->mmap_f   = prefix ## mmap;       \
     124             :     s->munmap_f = prefix ## munmap;     \
     125             : } while (0)
     126             : 
     127           0 :     if (s->use_libv4l2) {
     128             : #if CONFIG_LIBV4L2
     129             :         SET_WRAPPERS(v4l2_);
     130             : #else
     131           0 :         av_log(ctx, AV_LOG_ERROR, "libavdevice is not built with libv4l2 support.\n");
     132           0 :         return AVERROR(EINVAL);
     133             : #endif
     134             :     } else {
     135           0 :         SET_WRAPPERS();
     136             :     }
     137             : 
     138             : #define v4l2_open   s->open_f
     139             : #define v4l2_close  s->close_f
     140             : #define v4l2_dup    s->dup_f
     141             : #define v4l2_ioctl  s->ioctl_f
     142             : #define v4l2_read   s->read_f
     143             : #define v4l2_mmap   s->mmap_f
     144             : #define v4l2_munmap s->munmap_f
     145             : 
     146           0 :     if (ctx->flags & AVFMT_FLAG_NONBLOCK) {
     147           0 :         flags |= O_NONBLOCK;
     148             :     }
     149             : 
     150           0 :     fd = v4l2_open(ctx->filename, flags, 0);
     151           0 :     if (fd < 0) {
     152           0 :         err = AVERROR(errno);
     153           0 :         av_log(ctx, AV_LOG_ERROR, "Cannot open video device %s: %s\n",
     154           0 :                ctx->filename, av_err2str(err));
     155           0 :         return err;
     156             :     }
     157             : 
     158           0 :     if (v4l2_ioctl(fd, VIDIOC_QUERYCAP, &cap) < 0) {
     159           0 :         err = AVERROR(errno);
     160           0 :         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n",
     161           0 :                av_err2str(err));
     162           0 :         goto fail;
     163             :     }
     164             : 
     165           0 :     av_log(ctx, AV_LOG_VERBOSE, "fd:%d capabilities:%x\n",
     166             :            fd, cap.capabilities);
     167             : 
     168           0 :     if (!(cap.capabilities & V4L2_CAP_VIDEO_CAPTURE)) {
     169           0 :         av_log(ctx, AV_LOG_ERROR, "Not a video capture device.\n");
     170           0 :         err = AVERROR(ENODEV);
     171           0 :         goto fail;
     172             :     }
     173             : 
     174           0 :     if (!(cap.capabilities & V4L2_CAP_STREAMING)) {
     175           0 :         av_log(ctx, AV_LOG_ERROR,
     176             :                "The device does not support the streaming I/O method.\n");
     177           0 :         err = AVERROR(ENOSYS);
     178           0 :         goto fail;
     179             :     }
     180             : 
     181           0 :     return fd;
     182             : 
     183           0 : fail:
     184           0 :     v4l2_close(fd);
     185           0 :     return err;
     186             : }
     187             : 
     188           0 : static int device_init(AVFormatContext *ctx, int *width, int *height,
     189             :                        uint32_t pixelformat)
     190             : {
     191           0 :     struct video_data *s = ctx->priv_data;
     192           0 :     struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
     193           0 :     int res = 0;
     194             : 
     195           0 :     fmt.fmt.pix.width = *width;
     196           0 :     fmt.fmt.pix.height = *height;
     197           0 :     fmt.fmt.pix.pixelformat = pixelformat;
     198           0 :     fmt.fmt.pix.field = V4L2_FIELD_ANY;
     199             : 
     200             :     /* Some drivers will fail and return EINVAL when the pixelformat
     201             :        is not supported (even if type field is valid and supported) */
     202           0 :     if (v4l2_ioctl(s->fd, VIDIOC_S_FMT, &fmt) < 0)
     203           0 :         res = AVERROR(errno);
     204             : 
     205           0 :     if ((*width != fmt.fmt.pix.width) || (*height != fmt.fmt.pix.height)) {
     206           0 :         av_log(ctx, AV_LOG_INFO,
     207             :                "The V4L2 driver changed the video from %dx%d to %dx%d\n",
     208             :                *width, *height, fmt.fmt.pix.width, fmt.fmt.pix.height);
     209           0 :         *width = fmt.fmt.pix.width;
     210           0 :         *height = fmt.fmt.pix.height;
     211             :     }
     212             : 
     213           0 :     if (pixelformat != fmt.fmt.pix.pixelformat) {
     214           0 :         av_log(ctx, AV_LOG_DEBUG,
     215             :                "The V4L2 driver changed the pixel format "
     216             :                "from 0x%08X to 0x%08X\n",
     217             :                pixelformat, fmt.fmt.pix.pixelformat);
     218           0 :         res = AVERROR(EINVAL);
     219             :     }
     220             : 
     221           0 :     if (fmt.fmt.pix.field == V4L2_FIELD_INTERLACED) {
     222           0 :         av_log(ctx, AV_LOG_DEBUG,
     223             :                "The V4L2 driver is using the interlaced mode\n");
     224           0 :         s->interlaced = 1;
     225             :     }
     226             : 
     227           0 :     return res;
     228             : }
     229             : 
     230           0 : static int first_field(const struct video_data *s)
     231             : {
     232             :     int res;
     233             :     v4l2_std_id std;
     234             : 
     235           0 :     res = v4l2_ioctl(s->fd, VIDIOC_G_STD, &std);
     236           0 :     if (res < 0)
     237           0 :         return 0;
     238           0 :     if (std & V4L2_STD_NTSC)
     239           0 :         return 0;
     240             : 
     241           0 :     return 1;
     242             : }
     243             : 
     244             : #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
     245           0 : static void list_framesizes(AVFormatContext *ctx, uint32_t pixelformat)
     246             : {
     247           0 :     const struct video_data *s = ctx->priv_data;
     248           0 :     struct v4l2_frmsizeenum vfse = { .pixel_format = pixelformat };
     249             : 
     250           0 :     while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FRAMESIZES, &vfse)) {
     251           0 :         switch (vfse.type) {
     252           0 :         case V4L2_FRMSIZE_TYPE_DISCRETE:
     253           0 :             av_log(ctx, AV_LOG_INFO, " %ux%u",
     254             :                    vfse.discrete.width, vfse.discrete.height);
     255           0 :         break;
     256           0 :         case V4L2_FRMSIZE_TYPE_CONTINUOUS:
     257             :         case V4L2_FRMSIZE_TYPE_STEPWISE:
     258           0 :             av_log(ctx, AV_LOG_INFO, " {%u-%u, %u}x{%u-%u, %u}",
     259             :                    vfse.stepwise.min_width,
     260             :                    vfse.stepwise.max_width,
     261             :                    vfse.stepwise.step_width,
     262             :                    vfse.stepwise.min_height,
     263             :                    vfse.stepwise.max_height,
     264             :                    vfse.stepwise.step_height);
     265             :         }
     266           0 :         vfse.index++;
     267             :     }
     268           0 : }
     269             : #endif
     270             : 
     271           0 : static void list_formats(AVFormatContext *ctx, int type)
     272             : {
     273           0 :     const struct video_data *s = ctx->priv_data;
     274           0 :     struct v4l2_fmtdesc vfd = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
     275             : 
     276           0 :     while(!v4l2_ioctl(s->fd, VIDIOC_ENUM_FMT, &vfd)) {
     277           0 :         enum AVCodecID codec_id = ff_fmt_v4l2codec(vfd.pixelformat);
     278           0 :         enum AVPixelFormat pix_fmt = ff_fmt_v4l2ff(vfd.pixelformat, codec_id);
     279             : 
     280           0 :         vfd.index++;
     281             : 
     282           0 :         if (!(vfd.flags & V4L2_FMT_FLAG_COMPRESSED) &&
     283           0 :             type & V4L_RAWFORMATS) {
     284           0 :             const char *fmt_name = av_get_pix_fmt_name(pix_fmt);
     285           0 :             av_log(ctx, AV_LOG_INFO, "Raw       : %11s : %20s :",
     286             :                    fmt_name ? fmt_name : "Unsupported",
     287             :                    vfd.description);
     288           0 :         } else if (vfd.flags & V4L2_FMT_FLAG_COMPRESSED &&
     289           0 :                    type & V4L_COMPFORMATS) {
     290           0 :             const AVCodecDescriptor *desc = avcodec_descriptor_get(codec_id);
     291           0 :             av_log(ctx, AV_LOG_INFO, "Compressed: %11s : %20s :",
     292             :                    desc ? desc->name : "Unsupported",
     293             :                    vfd.description);
     294             :         } else {
     295           0 :             continue;
     296             :         }
     297             : 
     298             : #ifdef V4L2_FMT_FLAG_EMULATED
     299           0 :         if (vfd.flags & V4L2_FMT_FLAG_EMULATED)
     300           0 :             av_log(ctx, AV_LOG_INFO, " Emulated :");
     301             : #endif
     302             : #if HAVE_STRUCT_V4L2_FRMIVALENUM_DISCRETE
     303           0 :         list_framesizes(ctx, vfd.pixelformat);
     304             : #endif
     305           0 :         av_log(ctx, AV_LOG_INFO, "\n");
     306             :     }
     307           0 : }
     308             : 
     309           0 : static void list_standards(AVFormatContext *ctx)
     310             : {
     311             :     int ret;
     312           0 :     struct video_data *s = ctx->priv_data;
     313             :     struct v4l2_standard standard;
     314             : 
     315           0 :     if (s->std_id == 0)
     316           0 :         return;
     317             : 
     318           0 :     for (standard.index = 0; ; standard.index++) {
     319           0 :         if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
     320           0 :             ret = AVERROR(errno);
     321           0 :             if (ret == AVERROR(EINVAL)) {
     322           0 :                 break;
     323             :             } else {
     324           0 :                 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
     325           0 :                 return;
     326             :             }
     327             :         }
     328           0 :         av_log(ctx, AV_LOG_INFO, "%2d, %16"PRIx64", %s\n",
     329           0 :                standard.index, (uint64_t)standard.id, standard.name);
     330             :     }
     331             : }
     332             : 
     333           0 : static int mmap_init(AVFormatContext *ctx)
     334             : {
     335             :     int i, res;
     336           0 :     struct video_data *s = ctx->priv_data;
     337           0 :     struct v4l2_requestbuffers req = {
     338             :         .type   = V4L2_BUF_TYPE_VIDEO_CAPTURE,
     339             :         .count  = desired_video_buffers,
     340             :         .memory = V4L2_MEMORY_MMAP
     341             :     };
     342             : 
     343           0 :     if (v4l2_ioctl(s->fd, VIDIOC_REQBUFS, &req) < 0) {
     344           0 :         res = AVERROR(errno);
     345           0 :         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_REQBUFS): %s\n", av_err2str(res));
     346           0 :         return res;
     347             :     }
     348             : 
     349           0 :     if (req.count < 2) {
     350           0 :         av_log(ctx, AV_LOG_ERROR, "Insufficient buffer memory\n");
     351           0 :         return AVERROR(ENOMEM);
     352             :     }
     353           0 :     s->buffers = req.count;
     354           0 :     s->buf_start = av_malloc_array(s->buffers, sizeof(void *));
     355           0 :     if (!s->buf_start) {
     356           0 :         av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer pointers\n");
     357           0 :         return AVERROR(ENOMEM);
     358             :     }
     359           0 :     s->buf_len = av_malloc_array(s->buffers, sizeof(unsigned int));
     360           0 :     if (!s->buf_len) {
     361           0 :         av_log(ctx, AV_LOG_ERROR, "Cannot allocate buffer sizes\n");
     362           0 :         av_freep(&s->buf_start);
     363           0 :         return AVERROR(ENOMEM);
     364             :     }
     365             : 
     366           0 :     for (i = 0; i < req.count; i++) {
     367           0 :         struct v4l2_buffer buf = {
     368             :             .type   = V4L2_BUF_TYPE_VIDEO_CAPTURE,
     369             :             .index  = i,
     370             :             .memory = V4L2_MEMORY_MMAP
     371             :         };
     372           0 :         if (v4l2_ioctl(s->fd, VIDIOC_QUERYBUF, &buf) < 0) {
     373           0 :             res = AVERROR(errno);
     374           0 :             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYBUF): %s\n", av_err2str(res));
     375           0 :             return res;
     376             :         }
     377             : 
     378           0 :         s->buf_len[i] = buf.length;
     379           0 :         if (s->frame_size > 0 && s->buf_len[i] < s->frame_size) {
     380           0 :             av_log(ctx, AV_LOG_ERROR,
     381             :                    "buf_len[%d] = %d < expected frame size %d\n",
     382           0 :                    i, s->buf_len[i], s->frame_size);
     383           0 :             return AVERROR(ENOMEM);
     384             :         }
     385           0 :         s->buf_start[i] = v4l2_mmap(NULL, buf.length,
     386             :                                PROT_READ | PROT_WRITE, MAP_SHARED,
     387           0 :                                s->fd, buf.m.offset);
     388             : 
     389           0 :         if (s->buf_start[i] == MAP_FAILED) {
     390           0 :             res = AVERROR(errno);
     391           0 :             av_log(ctx, AV_LOG_ERROR, "mmap: %s\n", av_err2str(res));
     392           0 :             return res;
     393             :         }
     394             :     }
     395             : 
     396           0 :     return 0;
     397             : }
     398             : 
     399           0 : static int enqueue_buffer(struct video_data *s, struct v4l2_buffer *buf)
     400             : {
     401           0 :     int res = 0;
     402             : 
     403           0 :     if (v4l2_ioctl(s->fd, VIDIOC_QBUF, buf) < 0) {
     404           0 :         res = AVERROR(errno);
     405           0 :         av_log(NULL, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n", av_err2str(res));
     406             :     } else {
     407           0 :         atomic_fetch_add(&s->buffers_queued, 1);
     408             :     }
     409             : 
     410           0 :     return res;
     411             : }
     412             : 
     413           0 : static void mmap_release_buffer(void *opaque, uint8_t *data)
     414             : {
     415           0 :     struct v4l2_buffer buf = { 0 };
     416           0 :     struct buff_data *buf_descriptor = opaque;
     417           0 :     struct video_data *s = buf_descriptor->s;
     418             : 
     419           0 :     buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
     420           0 :     buf.memory = V4L2_MEMORY_MMAP;
     421           0 :     buf.index = buf_descriptor->index;
     422           0 :     av_free(buf_descriptor);
     423             : 
     424           0 :     enqueue_buffer(s, &buf);
     425           0 : }
     426             : 
     427             : #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
     428           0 : static int64_t av_gettime_monotonic(void)
     429             : {
     430           0 :     return av_gettime_relative();
     431             : }
     432             : #endif
     433             : 
     434           0 : static int init_convert_timestamp(AVFormatContext *ctx, int64_t ts)
     435             : {
     436           0 :     struct video_data *s = ctx->priv_data;
     437             :     int64_t now;
     438             : 
     439           0 :     now = av_gettime();
     440           0 :     if (s->ts_mode == V4L_TS_ABS &&
     441           0 :         ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE) {
     442           0 :         av_log(ctx, AV_LOG_INFO, "Detected absolute timestamps\n");
     443           0 :         s->ts_mode = V4L_TS_CONVERT_READY;
     444           0 :         return 0;
     445             :     }
     446             : #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
     447           0 :     if (ctx->streams[0]->avg_frame_rate.num) {
     448           0 :         now = av_gettime_monotonic();
     449           0 :         if (s->ts_mode == V4L_TS_MONO2ABS ||
     450           0 :             (ts <= now + 1 * AV_TIME_BASE && ts >= now - 10 * AV_TIME_BASE)) {
     451           0 :             AVRational tb = {AV_TIME_BASE, 1};
     452           0 :             int64_t period = av_rescale_q(1, tb, ctx->streams[0]->avg_frame_rate);
     453           0 :             av_log(ctx, AV_LOG_INFO, "Detected monotonic timestamps, converting\n");
     454             :             /* microseconds instead of seconds, MHz instead of Hz */
     455           0 :             s->timefilter = ff_timefilter_new(1, period, 1.0E-6);
     456           0 :             if (!s->timefilter)
     457           0 :                 return AVERROR(ENOMEM);
     458           0 :             s->ts_mode = V4L_TS_CONVERT_READY;
     459           0 :             return 0;
     460             :         }
     461             :     }
     462             : #endif
     463           0 :     av_log(ctx, AV_LOG_ERROR, "Unknown timestamps\n");
     464           0 :     return AVERROR(EIO);
     465             : }
     466             : 
     467           0 : static int convert_timestamp(AVFormatContext *ctx, int64_t *ts)
     468             : {
     469           0 :     struct video_data *s = ctx->priv_data;
     470             : 
     471           0 :     if (s->ts_mode) {
     472           0 :         int r = init_convert_timestamp(ctx, *ts);
     473           0 :         if (r < 0)
     474           0 :             return r;
     475             :     }
     476             : #if HAVE_CLOCK_GETTIME && defined(CLOCK_MONOTONIC)
     477           0 :     if (s->timefilter) {
     478           0 :         int64_t nowa = av_gettime();
     479           0 :         int64_t nowm = av_gettime_monotonic();
     480           0 :         ff_timefilter_update(s->timefilter, nowa, nowm - s->last_time_m);
     481           0 :         s->last_time_m = nowm;
     482           0 :         *ts = ff_timefilter_eval(s->timefilter, *ts - nowm);
     483             :     }
     484             : #endif
     485           0 :     return 0;
     486             : }
     487             : 
     488           0 : static int mmap_read_frame(AVFormatContext *ctx, AVPacket *pkt)
     489             : {
     490           0 :     struct video_data *s = ctx->priv_data;
     491           0 :     struct v4l2_buffer buf = {
     492             :         .type   = V4L2_BUF_TYPE_VIDEO_CAPTURE,
     493             :         .memory = V4L2_MEMORY_MMAP
     494             :     };
     495             :     struct timeval buf_ts;
     496             :     int res;
     497             : 
     498           0 :     pkt->size = 0;
     499             : 
     500             :     /* FIXME: Some special treatment might be needed in case of loss of signal... */
     501           0 :     while ((res = v4l2_ioctl(s->fd, VIDIOC_DQBUF, &buf)) < 0 && (errno == EINTR));
     502           0 :     if (res < 0) {
     503           0 :         if (errno == EAGAIN)
     504           0 :             return AVERROR(EAGAIN);
     505             : 
     506           0 :         res = AVERROR(errno);
     507           0 :         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_DQBUF): %s\n",
     508           0 :                av_err2str(res));
     509           0 :         return res;
     510             :     }
     511             : 
     512           0 :     buf_ts = buf.timestamp;
     513             : 
     514           0 :     if (buf.index >= s->buffers) {
     515           0 :         av_log(ctx, AV_LOG_ERROR, "Invalid buffer index received.\n");
     516           0 :         return AVERROR(EINVAL);
     517             :     }
     518           0 :     atomic_fetch_add(&s->buffers_queued, -1);
     519             :     // always keep at least one buffer queued
     520           0 :     av_assert0(atomic_load(&s->buffers_queued) >= 1);
     521             : 
     522             : #ifdef V4L2_BUF_FLAG_ERROR
     523           0 :     if (buf.flags & V4L2_BUF_FLAG_ERROR) {
     524           0 :         av_log(ctx, AV_LOG_WARNING,
     525             :                "Dequeued v4l2 buffer contains corrupted data (%d bytes).\n",
     526             :                buf.bytesused);
     527           0 :         buf.bytesused = 0;
     528             :     } else
     529             : #endif
     530             :     {
     531             :         /* CPIA is a compressed format and we don't know the exact number of bytes
     532             :          * used by a frame, so set it here as the driver announces it. */
     533           0 :         if (ctx->video_codec_id == AV_CODEC_ID_CPIA)
     534           0 :             s->frame_size = buf.bytesused;
     535             : 
     536           0 :         if (s->frame_size > 0 && buf.bytesused != s->frame_size) {
     537           0 :             av_log(ctx, AV_LOG_ERROR,
     538             :                    "Dequeued v4l2 buffer contains %d bytes, but %d were expected. Flags: 0x%08X.\n",
     539             :                    buf.bytesused, s->frame_size, buf.flags);
     540           0 :             enqueue_buffer(s, &buf);
     541           0 :             return AVERROR_INVALIDDATA;
     542             :         }
     543             :     }
     544             : 
     545             :     /* Image is at s->buff_start[buf.index] */
     546           0 :     if (atomic_load(&s->buffers_queued) == FFMAX(s->buffers / 8, 1)) {
     547             :         /* when we start getting low on queued buffers, fall back on copying data */
     548           0 :         res = av_new_packet(pkt, buf.bytesused);
     549           0 :         if (res < 0) {
     550           0 :             av_log(ctx, AV_LOG_ERROR, "Error allocating a packet.\n");
     551           0 :             enqueue_buffer(s, &buf);
     552           0 :             return res;
     553             :         }
     554           0 :         memcpy(pkt->data, s->buf_start[buf.index], buf.bytesused);
     555             : 
     556           0 :         res = enqueue_buffer(s, &buf);
     557           0 :         if (res) {
     558           0 :             av_packet_unref(pkt);
     559           0 :             return res;
     560             :         }
     561             :     } else {
     562             :         struct buff_data *buf_descriptor;
     563             : 
     564           0 :         pkt->data     = s->buf_start[buf.index];
     565           0 :         pkt->size     = buf.bytesused;
     566             : 
     567           0 :         buf_descriptor = av_malloc(sizeof(struct buff_data));
     568           0 :         if (!buf_descriptor) {
     569             :             /* Something went wrong... Since av_malloc() failed, we cannot even
     570             :              * allocate a buffer for memcpying into it
     571             :              */
     572           0 :             av_log(ctx, AV_LOG_ERROR, "Failed to allocate a buffer descriptor\n");
     573           0 :             enqueue_buffer(s, &buf);
     574             : 
     575           0 :             return AVERROR(ENOMEM);
     576             :         }
     577           0 :         buf_descriptor->index = buf.index;
     578           0 :         buf_descriptor->s     = s;
     579             : 
     580           0 :         pkt->buf = av_buffer_create(pkt->data, pkt->size, mmap_release_buffer,
     581             :                                     buf_descriptor, 0);
     582           0 :         if (!pkt->buf) {
     583           0 :             av_log(ctx, AV_LOG_ERROR, "Failed to create a buffer\n");
     584           0 :             enqueue_buffer(s, &buf);
     585           0 :             av_freep(&buf_descriptor);
     586           0 :             return AVERROR(ENOMEM);
     587             :         }
     588             :     }
     589           0 :     pkt->pts = buf_ts.tv_sec * INT64_C(1000000) + buf_ts.tv_usec;
     590           0 :     convert_timestamp(ctx, &pkt->pts);
     591             : 
     592           0 :     return pkt->size;
     593             : }
     594             : 
     595           0 : static int mmap_start(AVFormatContext *ctx)
     596             : {
     597           0 :     struct video_data *s = ctx->priv_data;
     598             :     enum v4l2_buf_type type;
     599             :     int i, res;
     600             : 
     601           0 :     for (i = 0; i < s->buffers; i++) {
     602           0 :         struct v4l2_buffer buf = {
     603             :             .type   = V4L2_BUF_TYPE_VIDEO_CAPTURE,
     604             :             .index  = i,
     605             :             .memory = V4L2_MEMORY_MMAP
     606             :         };
     607             : 
     608           0 :         if (v4l2_ioctl(s->fd, VIDIOC_QBUF, &buf) < 0) {
     609           0 :             res = AVERROR(errno);
     610           0 :             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QBUF): %s\n",
     611           0 :                    av_err2str(res));
     612           0 :             return res;
     613             :         }
     614             :     }
     615           0 :     atomic_store(&s->buffers_queued, s->buffers);
     616             : 
     617           0 :     type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
     618           0 :     if (v4l2_ioctl(s->fd, VIDIOC_STREAMON, &type) < 0) {
     619           0 :         res = AVERROR(errno);
     620           0 :         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_STREAMON): %s\n",
     621           0 :                av_err2str(res));
     622           0 :         return res;
     623             :     }
     624             : 
     625           0 :     return 0;
     626             : }
     627             : 
     628           0 : static void mmap_close(struct video_data *s)
     629             : {
     630             :     enum v4l2_buf_type type;
     631             :     int i;
     632             : 
     633           0 :     type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
     634             :     /* We do not check for the result, because we could
     635             :      * not do anything about it anyway...
     636             :      */
     637           0 :     v4l2_ioctl(s->fd, VIDIOC_STREAMOFF, &type);
     638           0 :     for (i = 0; i < s->buffers; i++) {
     639           0 :         v4l2_munmap(s->buf_start[i], s->buf_len[i]);
     640             :     }
     641           0 :     av_freep(&s->buf_start);
     642           0 :     av_freep(&s->buf_len);
     643           0 : }
     644             : 
     645           0 : static int v4l2_set_parameters(AVFormatContext *ctx)
     646             : {
     647           0 :     struct video_data *s = ctx->priv_data;
     648           0 :     struct v4l2_standard standard = { 0 };
     649           0 :     struct v4l2_streamparm streamparm = { 0 };
     650             :     struct v4l2_fract *tpf;
     651           0 :     AVRational framerate_q = { 0 };
     652             :     int i, ret;
     653             : 
     654           0 :     if (s->framerate &&
     655           0 :         (ret = av_parse_video_rate(&framerate_q, s->framerate)) < 0) {
     656           0 :         av_log(ctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n",
     657             :                s->framerate);
     658           0 :         return ret;
     659             :     }
     660             : 
     661           0 :     if (s->standard) {
     662           0 :         if (s->std_id) {
     663           0 :             ret = 0;
     664           0 :             av_log(ctx, AV_LOG_DEBUG, "Setting standard: %s\n", s->standard);
     665             :             /* set tv standard */
     666           0 :             for (i = 0; ; i++) {
     667           0 :                 standard.index = i;
     668           0 :                 if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
     669           0 :                     ret = AVERROR(errno);
     670           0 :                     break;
     671             :                 }
     672           0 :                 if (!av_strcasecmp(standard.name, s->standard))
     673           0 :                     break;
     674             :             }
     675           0 :             if (ret < 0) {
     676           0 :                 av_log(ctx, AV_LOG_ERROR, "Unknown or unsupported standard '%s'\n", s->standard);
     677           0 :                 return ret;
     678             :             }
     679             : 
     680           0 :             if (v4l2_ioctl(s->fd, VIDIOC_S_STD, &standard.id) < 0) {
     681           0 :                 ret = AVERROR(errno);
     682           0 :                 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_STD): %s\n", av_err2str(ret));
     683           0 :                 return ret;
     684             :             }
     685             :         } else {
     686           0 :             av_log(ctx, AV_LOG_WARNING,
     687             :                    "This device does not support any standard\n");
     688             :         }
     689             :     }
     690             : 
     691             :     /* get standard */
     692           0 :     if (v4l2_ioctl(s->fd, VIDIOC_G_STD, &s->std_id) == 0) {
     693           0 :         tpf = &standard.frameperiod;
     694           0 :         for (i = 0; ; i++) {
     695           0 :             standard.index = i;
     696           0 :             if (v4l2_ioctl(s->fd, VIDIOC_ENUMSTD, &standard) < 0) {
     697           0 :                 ret = AVERROR(errno);
     698           0 :                 if (ret == AVERROR(EINVAL)
     699             : #ifdef ENODATA
     700           0 :                     || ret == AVERROR(ENODATA)
     701             : #endif
     702             :                 ) {
     703           0 :                     tpf = &streamparm.parm.capture.timeperframe;
     704           0 :                     break;
     705             :                 }
     706           0 :                 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMSTD): %s\n", av_err2str(ret));
     707           0 :                 return ret;
     708             :             }
     709           0 :             if (standard.id == s->std_id) {
     710           0 :                 av_log(ctx, AV_LOG_DEBUG,
     711             :                        "Current standard: %s, id: %"PRIx64", frameperiod: %d/%d\n",
     712           0 :                        standard.name, (uint64_t)standard.id, tpf->numerator, tpf->denominator);
     713           0 :                 break;
     714             :             }
     715             :         }
     716             :     } else {
     717           0 :         tpf = &streamparm.parm.capture.timeperframe;
     718             :     }
     719             : 
     720           0 :     streamparm.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
     721           0 :     if (v4l2_ioctl(s->fd, VIDIOC_G_PARM, &streamparm) < 0) {
     722           0 :         ret = AVERROR(errno);
     723           0 :         av_log(ctx, AV_LOG_WARNING, "ioctl(VIDIOC_G_PARM): %s\n", av_err2str(ret));
     724           0 :     } else if (framerate_q.num && framerate_q.den) {
     725           0 :         if (streamparm.parm.capture.capability & V4L2_CAP_TIMEPERFRAME) {
     726           0 :             tpf = &streamparm.parm.capture.timeperframe;
     727             : 
     728           0 :             av_log(ctx, AV_LOG_DEBUG, "Setting time per frame to %d/%d\n",
     729             :                    framerate_q.den, framerate_q.num);
     730           0 :             tpf->numerator   = framerate_q.den;
     731           0 :             tpf->denominator = framerate_q.num;
     732             : 
     733           0 :             if (v4l2_ioctl(s->fd, VIDIOC_S_PARM, &streamparm) < 0) {
     734           0 :                 ret = AVERROR(errno);
     735           0 :                 av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_PARM): %s\n",
     736           0 :                        av_err2str(ret));
     737           0 :                 return ret;
     738             :             }
     739             : 
     740           0 :             if (framerate_q.num != tpf->denominator ||
     741           0 :                 framerate_q.den != tpf->numerator) {
     742           0 :                 av_log(ctx, AV_LOG_INFO,
     743             :                        "The driver changed the time per frame from "
     744             :                        "%d/%d to %d/%d\n",
     745             :                        framerate_q.den, framerate_q.num,
     746             :                        tpf->numerator, tpf->denominator);
     747             :             }
     748             :         } else {
     749           0 :             av_log(ctx, AV_LOG_WARNING,
     750             :                    "The driver does not permit changing the time per frame\n");
     751             :         }
     752             :     }
     753           0 :     if (tpf->denominator > 0 && tpf->numerator > 0) {
     754           0 :         ctx->streams[0]->avg_frame_rate.num = tpf->denominator;
     755           0 :         ctx->streams[0]->avg_frame_rate.den = tpf->numerator;
     756           0 :         ctx->streams[0]->r_frame_rate = ctx->streams[0]->avg_frame_rate;
     757             :     } else
     758           0 :         av_log(ctx, AV_LOG_WARNING, "Time per frame unknown\n");
     759             : 
     760           0 :     return 0;
     761             : }
     762             : 
     763           0 : static int device_try_init(AVFormatContext *ctx,
     764             :                            enum AVPixelFormat pix_fmt,
     765             :                            int *width,
     766             :                            int *height,
     767             :                            uint32_t *desired_format,
     768             :                            enum AVCodecID *codec_id)
     769             : {
     770             :     int ret, i;
     771             : 
     772           0 :     *desired_format = ff_fmt_ff2v4l(pix_fmt, ctx->video_codec_id);
     773             : 
     774           0 :     if (*desired_format) {
     775           0 :         ret = device_init(ctx, width, height, *desired_format);
     776           0 :         if (ret < 0) {
     777           0 :             *desired_format = 0;
     778           0 :             if (ret != AVERROR(EINVAL))
     779           0 :                 return ret;
     780             :         }
     781             :     }
     782             : 
     783           0 :     if (!*desired_format) {
     784           0 :         for (i = 0; ff_fmt_conversion_table[i].codec_id != AV_CODEC_ID_NONE; i++) {
     785           0 :             if (ctx->video_codec_id == AV_CODEC_ID_NONE ||
     786           0 :                 ff_fmt_conversion_table[i].codec_id == ctx->video_codec_id) {
     787           0 :                 av_log(ctx, AV_LOG_DEBUG, "Trying to set codec:%s pix_fmt:%s\n",
     788             :                        avcodec_get_name(ff_fmt_conversion_table[i].codec_id),
     789           0 :                        (char *)av_x_if_null(av_get_pix_fmt_name(ff_fmt_conversion_table[i].ff_fmt), "none"));
     790             : 
     791           0 :                 *desired_format = ff_fmt_conversion_table[i].v4l2_fmt;
     792           0 :                 ret = device_init(ctx, width, height, *desired_format);
     793           0 :                 if (ret >= 0)
     794           0 :                     break;
     795           0 :                 else if (ret != AVERROR(EINVAL))
     796           0 :                     return ret;
     797           0 :                 *desired_format = 0;
     798             :             }
     799             :         }
     800             : 
     801           0 :         if (*desired_format == 0) {
     802           0 :             av_log(ctx, AV_LOG_ERROR, "Cannot find a proper format for "
     803             :                    "codec '%s' (id %d), pixel format '%s' (id %d)\n",
     804           0 :                    avcodec_get_name(ctx->video_codec_id), ctx->video_codec_id,
     805           0 :                    (char *)av_x_if_null(av_get_pix_fmt_name(pix_fmt), "none"), pix_fmt);
     806           0 :             ret = AVERROR(EINVAL);
     807             :         }
     808             :     }
     809             : 
     810           0 :     *codec_id = ff_fmt_v4l2codec(*desired_format);
     811           0 :     av_assert0(*codec_id != AV_CODEC_ID_NONE);
     812           0 :     return ret;
     813             : }
     814             : 
     815        3081 : static int v4l2_read_probe(AVProbeData *p)
     816             : {
     817        3081 :     if (av_strstart(p->filename, "/dev/video", NULL))
     818           0 :         return AVPROBE_SCORE_MAX - 1;
     819        3081 :     return 0;
     820             : }
     821             : 
     822           0 : static int v4l2_read_header(AVFormatContext *ctx)
     823             : {
     824           0 :     struct video_data *s = ctx->priv_data;
     825             :     AVStream *st;
     826           0 :     int res = 0;
     827             :     uint32_t desired_format;
     828           0 :     enum AVCodecID codec_id = AV_CODEC_ID_NONE;
     829           0 :     enum AVPixelFormat pix_fmt = AV_PIX_FMT_NONE;
     830           0 :     struct v4l2_input input = { 0 };
     831             : 
     832           0 :     st = avformat_new_stream(ctx, NULL);
     833           0 :     if (!st)
     834           0 :         return AVERROR(ENOMEM);
     835             : 
     836             : #if CONFIG_LIBV4L2
     837             :     /* silence libv4l2 logging. if fopen() fails v4l2_log_file will be NULL
     838             :        and errors will get sent to stderr */
     839             :     if (s->use_libv4l2)
     840             :         v4l2_log_file = fopen("/dev/null", "w");
     841             : #endif
     842             : 
     843           0 :     s->fd = device_open(ctx);
     844           0 :     if (s->fd < 0)
     845           0 :         return s->fd;
     846             : 
     847           0 :     if (s->channel != -1) {
     848             :         /* set video input */
     849           0 :         av_log(ctx, AV_LOG_DEBUG, "Selecting input_channel: %d\n", s->channel);
     850           0 :         if (v4l2_ioctl(s->fd, VIDIOC_S_INPUT, &s->channel) < 0) {
     851           0 :             res = AVERROR(errno);
     852           0 :             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_S_INPUT): %s\n", av_err2str(res));
     853           0 :             goto fail;
     854             :         }
     855             :     } else {
     856             :         /* get current video input */
     857           0 :         if (v4l2_ioctl(s->fd, VIDIOC_G_INPUT, &s->channel) < 0) {
     858           0 :             res = AVERROR(errno);
     859           0 :             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_INPUT): %s\n", av_err2str(res));
     860           0 :             goto fail;
     861             :         }
     862             :     }
     863             : 
     864             :     /* enum input */
     865           0 :     input.index = s->channel;
     866           0 :     if (v4l2_ioctl(s->fd, VIDIOC_ENUMINPUT, &input) < 0) {
     867           0 :         res = AVERROR(errno);
     868           0 :         av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_ENUMINPUT): %s\n", av_err2str(res));
     869           0 :         goto fail;
     870             :     }
     871           0 :     s->std_id = input.std;
     872           0 :     av_log(ctx, AV_LOG_DEBUG, "Current input_channel: %d, input_name: %s, input_std: %"PRIx64"\n",
     873           0 :            s->channel, input.name, (uint64_t)input.std);
     874             : 
     875           0 :     if (s->list_format) {
     876           0 :         list_formats(ctx, s->list_format);
     877           0 :         res = AVERROR_EXIT;
     878           0 :         goto fail;
     879             :     }
     880             : 
     881           0 :     if (s->list_standard) {
     882           0 :         list_standards(ctx);
     883           0 :         res = AVERROR_EXIT;
     884           0 :         goto fail;
     885             :     }
     886             : 
     887           0 :     avpriv_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
     888             : 
     889           0 :     if (s->pixel_format) {
     890           0 :         const AVCodecDescriptor *desc = avcodec_descriptor_get_by_name(s->pixel_format);
     891             : 
     892           0 :         if (desc)
     893           0 :             ctx->video_codec_id = desc->id;
     894             : 
     895           0 :         pix_fmt = av_get_pix_fmt(s->pixel_format);
     896             : 
     897           0 :         if (pix_fmt == AV_PIX_FMT_NONE && !desc) {
     898           0 :             av_log(ctx, AV_LOG_ERROR, "No such input format: %s.\n",
     899             :                    s->pixel_format);
     900             : 
     901           0 :             res = AVERROR(EINVAL);
     902           0 :             goto fail;
     903             :         }
     904             :     }
     905             : 
     906           0 :     if (!s->width && !s->height) {
     907           0 :         struct v4l2_format fmt = { .type = V4L2_BUF_TYPE_VIDEO_CAPTURE };
     908             : 
     909           0 :         av_log(ctx, AV_LOG_VERBOSE,
     910             :                "Querying the device for the current frame size\n");
     911           0 :         if (v4l2_ioctl(s->fd, VIDIOC_G_FMT, &fmt) < 0) {
     912           0 :             res = AVERROR(errno);
     913           0 :             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_G_FMT): %s\n",
     914           0 :                    av_err2str(res));
     915           0 :             goto fail;
     916             :         }
     917             : 
     918           0 :         s->width  = fmt.fmt.pix.width;
     919           0 :         s->height = fmt.fmt.pix.height;
     920           0 :         av_log(ctx, AV_LOG_VERBOSE,
     921             :                "Setting frame size to %dx%d\n", s->width, s->height);
     922             :     }
     923             : 
     924           0 :     res = device_try_init(ctx, pix_fmt, &s->width, &s->height, &desired_format, &codec_id);
     925           0 :     if (res < 0)
     926           0 :         goto fail;
     927             : 
     928             :     /* If no pixel_format was specified, the codec_id was not known up
     929             :      * until now. Set video_codec_id in the context, as codec_id will
     930             :      * not be available outside this function
     931             :      */
     932           0 :     if (codec_id != AV_CODEC_ID_NONE && ctx->video_codec_id == AV_CODEC_ID_NONE)
     933           0 :         ctx->video_codec_id = codec_id;
     934             : 
     935           0 :     if ((res = av_image_check_size(s->width, s->height, 0, ctx)) < 0)
     936           0 :         goto fail;
     937             : 
     938           0 :     s->pixelformat = desired_format;
     939             : 
     940           0 :     if ((res = v4l2_set_parameters(ctx)) < 0)
     941           0 :         goto fail;
     942             : 
     943           0 :     st->codecpar->format = ff_fmt_v4l2ff(desired_format, codec_id);
     944           0 :     if (st->codecpar->format != AV_PIX_FMT_NONE)
     945           0 :         s->frame_size = av_image_get_buffer_size(st->codecpar->format,
     946             :                                                  s->width, s->height, 1);
     947             : 
     948           0 :     if ((res = mmap_init(ctx)) ||
     949             :         (res = mmap_start(ctx)) < 0)
     950             :             goto fail;
     951             : 
     952           0 :     s->top_field_first = first_field(s);
     953             : 
     954           0 :     st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
     955           0 :     st->codecpar->codec_id = codec_id;
     956           0 :     if (codec_id == AV_CODEC_ID_RAWVIDEO)
     957           0 :         st->codecpar->codec_tag =
     958           0 :             avcodec_pix_fmt_to_codec_tag(st->codecpar->format);
     959           0 :     else if (codec_id == AV_CODEC_ID_H264) {
     960           0 :         st->need_parsing = AVSTREAM_PARSE_FULL_ONCE;
     961             :     }
     962           0 :     if (desired_format == V4L2_PIX_FMT_YVU420)
     963           0 :         st->codecpar->codec_tag = MKTAG('Y', 'V', '1', '2');
     964           0 :     else if (desired_format == V4L2_PIX_FMT_YVU410)
     965           0 :         st->codecpar->codec_tag = MKTAG('Y', 'V', 'U', '9');
     966           0 :     st->codecpar->width = s->width;
     967           0 :     st->codecpar->height = s->height;
     968           0 :     if (st->avg_frame_rate.den)
     969           0 :         st->codecpar->bit_rate = s->frame_size * av_q2d(st->avg_frame_rate) * 8;
     970             : 
     971           0 :     return 0;
     972             : 
     973           0 : fail:
     974           0 :     v4l2_close(s->fd);
     975           0 :     return res;
     976             : }
     977             : 
     978           0 : static int v4l2_read_packet(AVFormatContext *ctx, AVPacket *pkt)
     979             : {
     980             : #if FF_API_CODED_FRAME && FF_API_LAVF_AVCTX
     981             : FF_DISABLE_DEPRECATION_WARNINGS
     982           0 :     struct video_data *s = ctx->priv_data;
     983           0 :     AVFrame *frame = ctx->streams[0]->codec->coded_frame;
     984             : FF_ENABLE_DEPRECATION_WARNINGS
     985             : #endif
     986             :     int res;
     987             : 
     988           0 :     if ((res = mmap_read_frame(ctx, pkt)) < 0) {
     989           0 :         return res;
     990             :     }
     991             : 
     992             : #if FF_API_CODED_FRAME && FF_API_LAVF_AVCTX
     993             : FF_DISABLE_DEPRECATION_WARNINGS
     994           0 :     if (frame && s->interlaced) {
     995           0 :         frame->interlaced_frame = 1;
     996           0 :         frame->top_field_first = s->top_field_first;
     997             :     }
     998             : FF_ENABLE_DEPRECATION_WARNINGS
     999             : #endif
    1000             : 
    1001           0 :     return pkt->size;
    1002             : }
    1003             : 
    1004           0 : static int v4l2_read_close(AVFormatContext *ctx)
    1005             : {
    1006           0 :     struct video_data *s = ctx->priv_data;
    1007             : 
    1008           0 :     if (atomic_load(&s->buffers_queued) != s->buffers)
    1009           0 :         av_log(ctx, AV_LOG_WARNING, "Some buffers are still owned by the caller on "
    1010             :                "close.\n");
    1011             : 
    1012           0 :     mmap_close(s);
    1013             : 
    1014           0 :     v4l2_close(s->fd);
    1015           0 :     return 0;
    1016             : }
    1017             : 
    1018           0 : static int v4l2_is_v4l_dev(const char *name)
    1019             : {
    1020           0 :     return !strncmp(name, "video", 5) ||
    1021           0 :            !strncmp(name, "radio", 5) ||
    1022           0 :            !strncmp(name, "vbi", 3) ||
    1023           0 :            !strncmp(name, "v4l-subdev", 10);
    1024             : }
    1025             : 
    1026           0 : static int v4l2_get_device_list(AVFormatContext *ctx, AVDeviceInfoList *device_list)
    1027             : {
    1028           0 :     struct video_data *s = ctx->priv_data;
    1029             :     DIR *dir;
    1030             :     struct dirent *entry;
    1031           0 :     AVDeviceInfo *device = NULL;
    1032             :     struct v4l2_capability cap;
    1033           0 :     int ret = 0;
    1034             : 
    1035           0 :     if (!device_list)
    1036           0 :         return AVERROR(EINVAL);
    1037             : 
    1038           0 :     dir = opendir("/dev");
    1039           0 :     if (!dir) {
    1040           0 :         ret = AVERROR(errno);
    1041           0 :         av_log(ctx, AV_LOG_ERROR, "Couldn't open the directory: %s\n", av_err2str(ret));
    1042           0 :         return ret;
    1043             :     }
    1044           0 :     while ((entry = readdir(dir))) {
    1045           0 :         if (!v4l2_is_v4l_dev(entry->d_name))
    1046           0 :             continue;
    1047             : 
    1048           0 :         snprintf(ctx->filename, sizeof(ctx->filename), "/dev/%s", entry->d_name);
    1049           0 :         if ((s->fd = device_open(ctx)) < 0)
    1050           0 :             continue;
    1051             : 
    1052           0 :         if (v4l2_ioctl(s->fd, VIDIOC_QUERYCAP, &cap) < 0) {
    1053           0 :             ret = AVERROR(errno);
    1054           0 :             av_log(ctx, AV_LOG_ERROR, "ioctl(VIDIOC_QUERYCAP): %s\n", av_err2str(ret));
    1055           0 :             goto fail;
    1056             :         }
    1057             : 
    1058           0 :         device = av_mallocz(sizeof(AVDeviceInfo));
    1059           0 :         if (!device) {
    1060           0 :             ret = AVERROR(ENOMEM);
    1061           0 :             goto fail;
    1062             :         }
    1063           0 :         device->device_name = av_strdup(ctx->filename);
    1064           0 :         device->device_description = av_strdup(cap.card);
    1065           0 :         if (!device->device_name || !device->device_description) {
    1066           0 :             ret = AVERROR(ENOMEM);
    1067           0 :             goto fail;
    1068             :         }
    1069             : 
    1070           0 :         if ((ret = av_dynarray_add_nofree(&device_list->devices,
    1071             :                                           &device_list->nb_devices, device)) < 0)
    1072           0 :             goto fail;
    1073             : 
    1074           0 :         v4l2_close(s->fd);
    1075           0 :         s->fd = -1;
    1076           0 :         continue;
    1077             : 
    1078           0 :       fail:
    1079           0 :         if (device) {
    1080           0 :             av_freep(&device->device_name);
    1081           0 :             av_freep(&device->device_description);
    1082           0 :             av_freep(&device);
    1083             :         }
    1084           0 :         if (s->fd >= 0)
    1085           0 :             v4l2_close(s->fd);
    1086           0 :         s->fd = -1;
    1087           0 :         break;
    1088             :     }
    1089           0 :     closedir(dir);
    1090           0 :     return ret;
    1091             : }
    1092             : 
    1093             : #define OFFSET(x) offsetof(struct video_data, x)
    1094             : #define DEC AV_OPT_FLAG_DECODING_PARAM
    1095             : 
    1096             : static const AVOption options[] = {
    1097             :     { "standard",     "set TV standard, used only by analog frame grabber",       OFFSET(standard),     AV_OPT_TYPE_STRING, {.str = NULL }, 0, 0,       DEC },
    1098             :     { "channel",      "set TV channel, used only by frame grabber",               OFFSET(channel),      AV_OPT_TYPE_INT,    {.i64 = -1 },  -1, INT_MAX, DEC },
    1099             :     { "video_size",   "set frame size",                                           OFFSET(width),        AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL},  0, 0,   DEC },
    1100             :     { "pixel_format", "set preferred pixel format",                               OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
    1101             :     { "input_format", "set preferred pixel format (for raw video) or codec name", OFFSET(pixel_format), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
    1102             :     { "framerate",    "set frame rate",                                           OFFSET(framerate),    AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       DEC },
    1103             : 
    1104             :     { "list_formats", "list available formats and exit",                          OFFSET(list_format),  AV_OPT_TYPE_INT,    {.i64 = 0 },  0, INT_MAX, DEC, "list_formats" },
    1105             :     { "all",          "show all available formats",                               OFFSET(list_format),  AV_OPT_TYPE_CONST,  {.i64 = V4L_ALLFORMATS  },    0, INT_MAX, DEC, "list_formats" },
    1106             :     { "raw",          "show only non-compressed formats",                         OFFSET(list_format),  AV_OPT_TYPE_CONST,  {.i64 = V4L_RAWFORMATS  },    0, INT_MAX, DEC, "list_formats" },
    1107             :     { "compressed",   "show only compressed formats",                             OFFSET(list_format),  AV_OPT_TYPE_CONST,  {.i64 = V4L_COMPFORMATS },    0, INT_MAX, DEC, "list_formats" },
    1108             : 
    1109             :     { "list_standards", "list supported standards and exit",                      OFFSET(list_standard), AV_OPT_TYPE_INT,   {.i64 = 0 },  0, 1, DEC, "list_standards" },
    1110             :     { "all",            "show all supported standards",                           OFFSET(list_standard), AV_OPT_TYPE_CONST, {.i64 = 1 },  0, 0, DEC, "list_standards" },
    1111             : 
    1112             :     { "timestamps",   "set type of timestamps for grabbed frames",                OFFSET(ts_mode),      AV_OPT_TYPE_INT,    {.i64 = 0 }, 0, 2, DEC, "timestamps" },
    1113             :     { "ts",           "set type of timestamps for grabbed frames",                OFFSET(ts_mode),      AV_OPT_TYPE_INT,    {.i64 = 0 }, 0, 2, DEC, "timestamps" },
    1114             :     { "default",      "use timestamps from the kernel",                           OFFSET(ts_mode),      AV_OPT_TYPE_CONST,  {.i64 = V4L_TS_DEFAULT  }, 0, 2, DEC, "timestamps" },
    1115             :     { "abs",          "use absolute timestamps (wall clock)",                     OFFSET(ts_mode),      AV_OPT_TYPE_CONST,  {.i64 = V4L_TS_ABS      }, 0, 2, DEC, "timestamps" },
    1116             :     { "mono2abs",     "force conversion from monotonic to absolute timestamps",   OFFSET(ts_mode),      AV_OPT_TYPE_CONST,  {.i64 = V4L_TS_MONO2ABS }, 0, 2, DEC, "timestamps" },
    1117             :     { "use_libv4l2",  "use libv4l2 (v4l-utils) conversion functions",             OFFSET(use_libv4l2),  AV_OPT_TYPE_BOOL,   {.i64 = 0}, 0, 1, DEC },
    1118             :     { NULL },
    1119             : };
    1120             : 
    1121             : static const AVClass v4l2_class = {
    1122             :     .class_name = "V4L2 indev",
    1123             :     .item_name  = av_default_item_name,
    1124             :     .option     = options,
    1125             :     .version    = LIBAVUTIL_VERSION_INT,
    1126             :     .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,
    1127             : };
    1128             : 
    1129             : AVInputFormat ff_v4l2_demuxer = {
    1130             :     .name           = "video4linux2,v4l2",
    1131             :     .long_name      = NULL_IF_CONFIG_SMALL("Video4Linux2 device grab"),
    1132             :     .priv_data_size = sizeof(struct video_data),
    1133             :     .read_probe     = v4l2_read_probe,
    1134             :     .read_header    = v4l2_read_header,
    1135             :     .read_packet    = v4l2_read_packet,
    1136             :     .read_close     = v4l2_read_close,
    1137             :     .get_device_list = v4l2_get_device_list,
    1138             :     .flags          = AVFMT_NOFILE,
    1139             :     .priv_class     = &v4l2_class,
    1140             : };

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