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libavdevice/v4l.c

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00001 /*
00002  * Linux video grab interface
00003  * Copyright (c) 2000,2001 Fabrice Bellard
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "avdevice.h"
00023 
00024 #if FF_API_V4L
00025 
00026 #undef __STRICT_ANSI__ //workaround due to broken kernel headers
00027 #include "config.h"
00028 #include "libavutil/rational.h"
00029 #include "libavutil/imgutils.h"
00030 #include "libavutil/log.h"
00031 #include "libavutil/opt.h"
00032 #include "libavcodec/dsputil.h"
00033 #include <unistd.h>
00034 #include <fcntl.h>
00035 #include <sys/ioctl.h>
00036 #include <sys/mman.h>
00037 #include <sys/time.h>
00038 #define _LINUX_TIME_H 1
00039 #include <linux/videodev.h>
00040 #include <time.h>
00041 #include <strings.h>
00042 #include "avdevice.h"
00043 
00044 typedef struct {
00045     AVClass *class;
00046     int fd;
00047     int frame_format; /* see VIDEO_PALETTE_xxx */
00048     int use_mmap;
00049     AVRational time_base;
00050     int64_t time_frame;
00051     int frame_size;
00052     struct video_capability video_cap;
00053     struct video_audio audio_saved;
00054     struct video_window video_win;
00055     uint8_t *video_buf;
00056     struct video_mbuf gb_buffers;
00057     struct video_mmap gb_buf;
00058     int gb_frame;
00059     int standard;
00060 } VideoData;
00061 
00062 static const struct {
00063     int palette;
00064     int depth;
00065     enum PixelFormat pix_fmt;
00066 } video_formats [] = {
00067     {.palette = VIDEO_PALETTE_YUV420P, .depth = 12, .pix_fmt = PIX_FMT_YUV420P },
00068     {.palette = VIDEO_PALETTE_YUV422,  .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
00069     {.palette = VIDEO_PALETTE_UYVY,    .depth = 16, .pix_fmt = PIX_FMT_UYVY422 },
00070     {.palette = VIDEO_PALETTE_YUYV,    .depth = 16, .pix_fmt = PIX_FMT_YUYV422 },
00071     /* NOTE: v4l uses BGR24, not RGB24 */
00072     {.palette = VIDEO_PALETTE_RGB24,   .depth = 24, .pix_fmt = PIX_FMT_BGR24   },
00073     {.palette = VIDEO_PALETTE_RGB565,  .depth = 16, .pix_fmt = PIX_FMT_BGR565  },
00074     {.palette = VIDEO_PALETTE_GREY,    .depth = 8,  .pix_fmt = PIX_FMT_GRAY8   },
00075 };
00076 
00077 
00078 static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap)
00079 {
00080     VideoData *s = s1->priv_data;
00081     AVStream *st;
00082     int video_fd;
00083     int desired_palette, desired_depth;
00084     struct video_tuner tuner;
00085     struct video_audio audio;
00086     struct video_picture pict;
00087     int j;
00088     int vformat_num = FF_ARRAY_ELEMS(video_formats);
00089 
00090     av_log(s1, AV_LOG_WARNING, "V4L input device is deprecated and will be removed in the next release.");
00091 
00092     if (ap->time_base.den <= 0) {
00093         av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den);
00094         return -1;
00095     }
00096     s->time_base = ap->time_base;
00097 
00098     s->video_win.width = ap->width;
00099     s->video_win.height = ap->height;
00100 
00101     st = av_new_stream(s1, 0);
00102     if (!st)
00103         return AVERROR(ENOMEM);
00104     av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */
00105 
00106     video_fd = open(s1->filename, O_RDWR);
00107     if (video_fd < 0) {
00108         av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno));
00109         goto fail;
00110     }
00111 
00112     if (ioctl(video_fd, VIDIOCGCAP, &s->video_cap) < 0) {
00113         av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno));
00114         goto fail;
00115     }
00116 
00117     if (!(s->video_cap.type & VID_TYPE_CAPTURE)) {
00118         av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n");
00119         goto fail;
00120     }
00121 
00122     /* no values set, autodetect them */
00123     if (s->video_win.width <= 0 || s->video_win.height <= 0) {
00124         if (ioctl(video_fd, VIDIOCGWIN, &s->video_win, sizeof(s->video_win)) < 0) {
00125             av_log(s1, AV_LOG_ERROR, "VIDIOCGWIN: %s\n", strerror(errno));
00126             goto fail;
00127         }
00128     }
00129 
00130     if(av_image_check_size(s->video_win.width, s->video_win.height, 0, s1) < 0)
00131         return -1;
00132 
00133     desired_palette = -1;
00134     desired_depth = -1;
00135     for (j = 0; j < vformat_num; j++) {
00136         if (ap->pix_fmt == video_formats[j].pix_fmt) {
00137             desired_palette = video_formats[j].palette;
00138             desired_depth = video_formats[j].depth;
00139             break;
00140         }
00141     }
00142 
00143     /* set tv standard */
00144     if (!ioctl(video_fd, VIDIOCGTUNER, &tuner)) {
00145 #if FF_API_FORMAT_PARAMETERS
00146         if (ap->standard) {
00147             if (!strcasecmp(ap->standard, "pal"))
00148                 s->standard = VIDEO_MODE_PAL;
00149             else if (!strcasecmp(ap->standard, "secam"))
00150                 s->standard = VIDEO_MODE_SECAM;
00151             else
00152                 s->standard = VIDEO_MODE_NTSC;
00153         }
00154 #endif
00155         tuner.mode = s->standard;
00156         ioctl(video_fd, VIDIOCSTUNER, &tuner);
00157     }
00158 
00159     /* unmute audio */
00160     audio.audio = 0;
00161     ioctl(video_fd, VIDIOCGAUDIO, &audio);
00162     memcpy(&s->audio_saved, &audio, sizeof(audio));
00163     audio.flags &= ~VIDEO_AUDIO_MUTE;
00164     ioctl(video_fd, VIDIOCSAUDIO, &audio);
00165 
00166     ioctl(video_fd, VIDIOCGPICT, &pict);
00167 #if 0
00168     printf("v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n",
00169            pict.colour,
00170            pict.hue,
00171            pict.brightness,
00172            pict.contrast,
00173            pict.whiteness);
00174 #endif
00175     /* try to choose a suitable video format */
00176     pict.palette = desired_palette;
00177     pict.depth= desired_depth;
00178     if (desired_palette == -1 || ioctl(video_fd, VIDIOCSPICT, &pict) < 0) {
00179         for (j = 0; j < vformat_num; j++) {
00180             pict.palette = video_formats[j].palette;
00181             pict.depth = video_formats[j].depth;
00182             if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict))
00183                 break;
00184         }
00185         if (j >= vformat_num)
00186             goto fail1;
00187     }
00188 
00189     if (ioctl(video_fd, VIDIOCGMBUF, &s->gb_buffers) < 0) {
00190         /* try to use read based access */
00191         int val;
00192 
00193         s->video_win.x = 0;
00194         s->video_win.y = 0;
00195         s->video_win.chromakey = -1;
00196         s->video_win.flags = 0;
00197 
00198         if (ioctl(video_fd, VIDIOCSWIN, s->video_win) < 0) {
00199             av_log(s1, AV_LOG_ERROR, "VIDIOCSWIN: %s\n", strerror(errno));
00200             goto fail;
00201         }
00202 
00203         s->frame_format = pict.palette;
00204 
00205         val = 1;
00206         if (ioctl(video_fd, VIDIOCCAPTURE, &val) < 0) {
00207             av_log(s1, AV_LOG_ERROR, "VIDIOCCAPTURE: %s\n", strerror(errno));
00208             goto fail;
00209         }
00210 
00211         s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
00212         s->use_mmap = 0;
00213     } else {
00214         s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_SHARED, video_fd, 0);
00215         if ((unsigned char*)-1 == s->video_buf) {
00216             s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_PRIVATE, video_fd, 0);
00217             if ((unsigned char*)-1 == s->video_buf) {
00218                 av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno));
00219                 goto fail;
00220             }
00221         }
00222         s->gb_frame = 0;
00223         s->time_frame = av_gettime() * s->time_base.den / s->time_base.num;
00224 
00225         /* start to grab the first frame */
00226         s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames;
00227         s->gb_buf.height = s->video_win.height;
00228         s->gb_buf.width = s->video_win.width;
00229         s->gb_buf.format = pict.palette;
00230 
00231         if (ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
00232             if (errno != EAGAIN) {
00233             fail1:
00234                 av_log(s1, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
00235             } else {
00236                 av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not receive any video signal\n");
00237             }
00238             goto fail;
00239         }
00240         for (j = 1; j < s->gb_buffers.frames; j++) {
00241           s->gb_buf.frame = j;
00242           ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf);
00243         }
00244         s->frame_format = s->gb_buf.format;
00245         s->use_mmap = 1;
00246     }
00247 
00248     for (j = 0; j < vformat_num; j++) {
00249         if (s->frame_format == video_formats[j].palette) {
00250             s->frame_size = s->video_win.width * s->video_win.height * video_formats[j].depth / 8;
00251             st->codec->pix_fmt = video_formats[j].pix_fmt;
00252             break;
00253         }
00254     }
00255 
00256     if (j >= vformat_num)
00257         goto fail;
00258 
00259     s->fd = video_fd;
00260 
00261     st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
00262     st->codec->codec_id = CODEC_ID_RAWVIDEO;
00263     st->codec->width = s->video_win.width;
00264     st->codec->height = s->video_win.height;
00265     st->codec->time_base = s->time_base;
00266     st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8;
00267 
00268     return 0;
00269  fail:
00270     if (video_fd >= 0)
00271         close(video_fd);
00272     return AVERROR(EIO);
00273 }
00274 
00275 static int v4l_mm_read_picture(VideoData *s, uint8_t *buf)
00276 {
00277     uint8_t *ptr;
00278 
00279     while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 &&
00280            (errno == EAGAIN || errno == EINTR));
00281 
00282     ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame];
00283     memcpy(buf, ptr, s->frame_size);
00284 
00285     /* Setup to capture the next frame */
00286     s->gb_buf.frame = s->gb_frame;
00287     if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) {
00288         if (errno == EAGAIN)
00289             av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n");
00290         else
00291             av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno));
00292         return AVERROR(EIO);
00293     }
00294 
00295     /* This is now the grabbing frame */
00296     s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames;
00297 
00298     return s->frame_size;
00299 }
00300 
00301 static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt)
00302 {
00303     VideoData *s = s1->priv_data;
00304     int64_t curtime, delay;
00305     struct timespec ts;
00306 
00307     /* Calculate the time of the next frame */
00308     s->time_frame += INT64_C(1000000);
00309 
00310     /* wait based on the frame rate */
00311     for(;;) {
00312         curtime = av_gettime();
00313         delay = s->time_frame * s->time_base.num / s->time_base.den - curtime;
00314         if (delay <= 0) {
00315             if (delay < INT64_C(-1000000) * s->time_base.num / s->time_base.den) {
00316                 /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */
00317                 s->time_frame += INT64_C(1000000);
00318             }
00319             break;
00320         }
00321         ts.tv_sec = delay / 1000000;
00322         ts.tv_nsec = (delay % 1000000) * 1000;
00323         nanosleep(&ts, NULL);
00324     }
00325 
00326     if (av_new_packet(pkt, s->frame_size) < 0)
00327         return AVERROR(EIO);
00328 
00329     pkt->pts = curtime;
00330 
00331     /* read one frame */
00332     if (s->use_mmap) {
00333         return v4l_mm_read_picture(s, pkt->data);
00334     } else {
00335         if (read(s->fd, pkt->data, pkt->size) != pkt->size)
00336             return AVERROR(EIO);
00337         return s->frame_size;
00338     }
00339 }
00340 
00341 static int grab_read_close(AVFormatContext *s1)
00342 {
00343     VideoData *s = s1->priv_data;
00344 
00345     if (s->use_mmap)
00346         munmap(s->video_buf, s->gb_buffers.size);
00347 
00348     /* mute audio. we must force it because the BTTV driver does not
00349        return its state correctly */
00350     s->audio_saved.flags |= VIDEO_AUDIO_MUTE;
00351     ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved);
00352 
00353     close(s->fd);
00354     return 0;
00355 }
00356 
00357 static const AVOption options[] = {
00358     { "standard", "", offsetof(VideoData, standard), FF_OPT_TYPE_INT, {.dbl = VIDEO_MODE_NTSC}, VIDEO_MODE_PAL, VIDEO_MODE_NTSC, AV_OPT_FLAG_DECODING_PARAM, "standard" },
00359     { "PAL",   "", 0, FF_OPT_TYPE_CONST, {.dbl = VIDEO_MODE_PAL},   0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
00360     { "SECAM", "", 0, FF_OPT_TYPE_CONST, {.dbl = VIDEO_MODE_SECAM}, 0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
00361     { "NTSC",  "", 0, FF_OPT_TYPE_CONST, {.dbl = VIDEO_MODE_NTSC},  0, 0, AV_OPT_FLAG_DECODING_PARAM, "standard" },
00362     { NULL },
00363 };
00364 
00365 static const AVClass v4l_class = {
00366     .class_name = "V4L indev",
00367     .item_name  = av_default_item_name,
00368     .option     = options,
00369     .version    = LIBAVUTIL_VERSION_INT,
00370 };
00371 
00372 AVInputFormat ff_v4l_demuxer = {
00373     "video4linux",
00374     NULL_IF_CONFIG_SMALL("Video4Linux device grab"),
00375     sizeof(VideoData),
00376     NULL,
00377     grab_read_header,
00378     grab_read_packet,
00379     grab_read_close,
00380     .flags = AVFMT_NOFILE,
00381     .priv_class = &v4l_class,
00382 };
00383 #endif  /* FF_API_V4L */

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