/* * Linux video grab interface * Copyright (c) 2000,2001 Fabrice Bellard * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #undef __STRICT_ANSI__ //workaround due to broken kernel headers #include "config.h" #include "libavutil/rational.h" #include "libavutil/imgutils.h" #include "libavformat/avformat.h" #include "libavcodec/dsputil.h" #include <unistd.h> #include <fcntl.h> #include <sys/ioctl.h> #include <sys/mman.h> #include <sys/time.h> #define _LINUX_TIME_H 1 #include <linux/videodev.h> #include <time.h> #include <strings.h> typedef struct { int fd; int frame_format; /* see VIDEO_PALETTE_xxx */ int use_mmap; AVRational time_base; int64_t time_frame; int frame_size; struct video_capability video_cap; struct video_audio audio_saved; struct video_window video_win; uint8_t *video_buf; struct video_mbuf gb_buffers; struct video_mmap gb_buf; int gb_frame; } VideoData; static const struct { int palette; int depth; enum PixelFormat pix_fmt; } video_formats [] = { {.palette = VIDEO_PALETTE_YUV420P, .depth = 12, .pix_fmt = PIX_FMT_YUV420P }, {.palette = VIDEO_PALETTE_YUV422, .depth = 16, .pix_fmt = PIX_FMT_YUYV422 }, {.palette = VIDEO_PALETTE_UYVY, .depth = 16, .pix_fmt = PIX_FMT_UYVY422 }, {.palette = VIDEO_PALETTE_YUYV, .depth = 16, .pix_fmt = PIX_FMT_YUYV422 }, /* NOTE: v4l uses BGR24, not RGB24 */ {.palette = VIDEO_PALETTE_RGB24, .depth = 24, .pix_fmt = PIX_FMT_BGR24 }, {.palette = VIDEO_PALETTE_RGB565, .depth = 16, .pix_fmt = PIX_FMT_BGR565 }, {.palette = VIDEO_PALETTE_GREY, .depth = 8, .pix_fmt = PIX_FMT_GRAY8 }, }; static int grab_read_header(AVFormatContext *s1, AVFormatParameters *ap) { VideoData *s = s1->priv_data; AVStream *st; int video_fd; int desired_palette, desired_depth; struct video_tuner tuner; struct video_audio audio; struct video_picture pict; int j; int vformat_num = FF_ARRAY_ELEMS(video_formats); if (ap->time_base.den <= 0) { av_log(s1, AV_LOG_ERROR, "Wrong time base (%d)\n", ap->time_base.den); return -1; } s->time_base = ap->time_base; s->video_win.width = ap->width; s->video_win.height = ap->height; st = av_new_stream(s1, 0); if (!st) return AVERROR(ENOMEM); av_set_pts_info(st, 64, 1, 1000000); /* 64 bits pts in us */ video_fd = open(s1->filename, O_RDWR); if (video_fd < 0) { av_log(s1, AV_LOG_ERROR, "%s: %s\n", s1->filename, strerror(errno)); goto fail; } if (ioctl(video_fd, VIDIOCGCAP, &s->video_cap) < 0) { av_log(s1, AV_LOG_ERROR, "VIDIOCGCAP: %s\n", strerror(errno)); goto fail; } if (!(s->video_cap.type & VID_TYPE_CAPTURE)) { av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not handle capture\n"); goto fail; } /* no values set, autodetect them */ if (s->video_win.width <= 0 || s->video_win.height <= 0) { if (ioctl(video_fd, VIDIOCGWIN, &s->video_win, sizeof(s->video_win)) < 0) { av_log(s1, AV_LOG_ERROR, "VIDIOCGWIN: %s\n", strerror(errno)); goto fail; } } if(av_image_check_size(s->video_win.width, s->video_win.height, 0, s1) < 0) return -1; desired_palette = -1; desired_depth = -1; for (j = 0; j < vformat_num; j++) { if (ap->pix_fmt == video_formats[j].pix_fmt) { desired_palette = video_formats[j].palette; desired_depth = video_formats[j].depth; break; } } /* set tv standard */ if (ap->standard && !ioctl(video_fd, VIDIOCGTUNER, &tuner)) { if (!strcasecmp(ap->standard, "pal")) tuner.mode = VIDEO_MODE_PAL; else if (!strcasecmp(ap->standard, "secam")) tuner.mode = VIDEO_MODE_SECAM; else tuner.mode = VIDEO_MODE_NTSC; ioctl(video_fd, VIDIOCSTUNER, &tuner); } /* unmute audio */ audio.audio = 0; ioctl(video_fd, VIDIOCGAUDIO, &audio); memcpy(&s->audio_saved, &audio, sizeof(audio)); audio.flags &= ~VIDEO_AUDIO_MUTE; ioctl(video_fd, VIDIOCSAUDIO, &audio); ioctl(video_fd, VIDIOCGPICT, &pict); #if 0 printf("v4l: colour=%d hue=%d brightness=%d constrast=%d whiteness=%d\n", pict.colour, pict.hue, pict.brightness, pict.contrast, pict.whiteness); #endif /* try to choose a suitable video format */ pict.palette = desired_palette; pict.depth= desired_depth; if (desired_palette == -1 || ioctl(video_fd, VIDIOCSPICT, &pict) < 0) { for (j = 0; j < vformat_num; j++) { pict.palette = video_formats[j].palette; pict.depth = video_formats[j].depth; if (-1 != ioctl(video_fd, VIDIOCSPICT, &pict)) break; } if (j >= vformat_num) goto fail1; } if (ioctl(video_fd, VIDIOCGMBUF, &s->gb_buffers) < 0) { /* try to use read based access */ int val; s->video_win.x = 0; s->video_win.y = 0; s->video_win.chromakey = -1; s->video_win.flags = 0; if (ioctl(video_fd, VIDIOCSWIN, s->video_win) < 0) { av_log(s1, AV_LOG_ERROR, "VIDIOCSWIN: %s\n", strerror(errno)); goto fail; } s->frame_format = pict.palette; val = 1; if (ioctl(video_fd, VIDIOCCAPTURE, &val) < 0) { av_log(s1, AV_LOG_ERROR, "VIDIOCCAPTURE: %s\n", strerror(errno)); goto fail; } s->time_frame = av_gettime() * s->time_base.den / s->time_base.num; s->use_mmap = 0; } else { s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_SHARED, video_fd, 0); if ((unsigned char*)-1 == s->video_buf) { s->video_buf = mmap(0, s->gb_buffers.size, PROT_READ|PROT_WRITE, MAP_PRIVATE, video_fd, 0); if ((unsigned char*)-1 == s->video_buf) { av_log(s1, AV_LOG_ERROR, "mmap: %s\n", strerror(errno)); goto fail; } } s->gb_frame = 0; s->time_frame = av_gettime() * s->time_base.den / s->time_base.num; /* start to grab the first frame */ s->gb_buf.frame = s->gb_frame % s->gb_buffers.frames; s->gb_buf.height = s->video_win.height; s->gb_buf.width = s->video_win.width; s->gb_buf.format = pict.palette; if (ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) { if (errno != EAGAIN) { fail1: av_log(s1, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno)); } else { av_log(s1, AV_LOG_ERROR, "Fatal: grab device does not receive any video signal\n"); } goto fail; } for (j = 1; j < s->gb_buffers.frames; j++) { s->gb_buf.frame = j; ioctl(video_fd, VIDIOCMCAPTURE, &s->gb_buf); } s->frame_format = s->gb_buf.format; s->use_mmap = 1; } for (j = 0; j < vformat_num; j++) { if (s->frame_format == video_formats[j].palette) { s->frame_size = s->video_win.width * s->video_win.height * video_formats[j].depth / 8; st->codec->pix_fmt = video_formats[j].pix_fmt; break; } } if (j >= vformat_num) goto fail; s->fd = video_fd; st->codec->codec_type = AVMEDIA_TYPE_VIDEO; st->codec->codec_id = CODEC_ID_RAWVIDEO; st->codec->width = s->video_win.width; st->codec->height = s->video_win.height; st->codec->time_base = s->time_base; st->codec->bit_rate = s->frame_size * 1/av_q2d(st->codec->time_base) * 8; return 0; fail: if (video_fd >= 0) close(video_fd); return AVERROR(EIO); } static int v4l_mm_read_picture(VideoData *s, uint8_t *buf) { uint8_t *ptr; while (ioctl(s->fd, VIDIOCSYNC, &s->gb_frame) < 0 && (errno == EAGAIN || errno == EINTR)); ptr = s->video_buf + s->gb_buffers.offsets[s->gb_frame]; memcpy(buf, ptr, s->frame_size); /* Setup to capture the next frame */ s->gb_buf.frame = s->gb_frame; if (ioctl(s->fd, VIDIOCMCAPTURE, &s->gb_buf) < 0) { if (errno == EAGAIN) av_log(NULL, AV_LOG_ERROR, "Cannot Sync\n"); else av_log(NULL, AV_LOG_ERROR, "VIDIOCMCAPTURE: %s\n", strerror(errno)); return AVERROR(EIO); } /* This is now the grabbing frame */ s->gb_frame = (s->gb_frame + 1) % s->gb_buffers.frames; return s->frame_size; } static int grab_read_packet(AVFormatContext *s1, AVPacket *pkt) { VideoData *s = s1->priv_data; int64_t curtime, delay; struct timespec ts; /* Calculate the time of the next frame */ s->time_frame += INT64_C(1000000); /* wait based on the frame rate */ for(;;) { curtime = av_gettime(); delay = s->time_frame * s->time_base.num / s->time_base.den - curtime; if (delay <= 0) { if (delay < INT64_C(-1000000) * s->time_base.num / s->time_base.den) { /* printf("grabbing is %d frames late (dropping)\n", (int) -(delay / 16666)); */ s->time_frame += INT64_C(1000000); } break; } ts.tv_sec = delay / 1000000; ts.tv_nsec = (delay % 1000000) * 1000; nanosleep(&ts, NULL); } if (av_new_packet(pkt, s->frame_size) < 0) return AVERROR(EIO); pkt->pts = curtime; /* read one frame */ if (s->use_mmap) { return v4l_mm_read_picture(s, pkt->data); } else { if (read(s->fd, pkt->data, pkt->size) != pkt->size) return AVERROR(EIO); return s->frame_size; } } static int grab_read_close(AVFormatContext *s1) { VideoData *s = s1->priv_data; if (s->use_mmap) munmap(s->video_buf, s->gb_buffers.size); /* mute audio. we must force it because the BTTV driver does not return its state correctly */ s->audio_saved.flags |= VIDEO_AUDIO_MUTE; ioctl(s->fd, VIDIOCSAUDIO, &s->audio_saved); close(s->fd); return 0; } AVInputFormat ff_v4l_demuxer = { "video4linux", NULL_IF_CONFIG_SMALL("Video4Linux device grab"), sizeof(VideoData), NULL, grab_read_header, grab_read_packet, grab_read_close, .flags = AVFMT_NOFILE, };