diff options
Diffstat (limited to 'grab.c')
| -rw-r--r-- | grab.c | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/grab.c b/grab.c new file mode 100644 index 0000000000..807d4c5420 --- /dev/null +++ b/grab.c @@ -0,0 +1,258 @@ +/* + * Linux audio/video grab interface + * Copyright (c) 2000 Gerard Lantau. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ +#include <stdlib.h> +#include <stdio.h> +#include <netinet/in.h> +#include <linux/videodev.h> +#include <linux/soundcard.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <errno.h> +#include <sys/time.h> +#include <getopt.h> + +#include "mpegenc.h" +#include "mpegvideo.h" + +long long gettime(void) +{ + struct timeval tv; + gettimeofday(&tv,NULL); + return (long long)tv.tv_sec * 1000000 + tv.tv_usec; +} + +/* v4l capture */ + +const char *v4l_device = "/dev/video"; + +static struct video_capability video_cap; +int video_fd = -1; +UINT8 *video_buf, *picture_buf; +struct video_mbuf gb_buffers; +struct video_mmap gb_buf; +struct video_audio audio; +int gb_frame = 0; +long long time_frame; +int frame_rate; +int use_mmap = 0; + +int v4l_init(int rate, int width, int height) +{ + frame_rate = rate; + + video_fd = open(v4l_device, O_RDWR); + + if (ioctl(video_fd,VIDIOCGCAP,&video_cap) < 0) { + perror("VIDIOCGCAP"); + return -1; + } + + /* unmute audio */ + ioctl(video_fd, VIDIOCGAUDIO, &audio); + audio.flags &= ~VIDEO_AUDIO_MUTE; + ioctl(video_fd, VIDIOCSAUDIO, &audio); + + if (!(video_cap.type & VID_TYPE_CAPTURE)) { + /* try to use read based access */ + struct video_window win; + int val; + + win.x = 0; + win.y = 0; + win.width = width; + win.height = height; + win.chromakey = -1; + win.flags = 0; + + ioctl(video_fd, VIDIOCSWIN, &win); + + val = 1; + ioctl(video_fd, VIDIOCCAPTURE, &val); + video_buf = malloc( width * height * 2); + picture_buf = malloc( (width * height * 3) / 2); + use_mmap = 0; + return 0; + } + + if (ioctl(video_fd,VIDIOCGMBUF,&gb_buffers) < 0) { + perror("ioctl VIDIOCGMBUF"); + } + + video_buf = mmap(0,gb_buffers.size,PROT_READ|PROT_WRITE,MAP_SHARED,video_fd,0); + if ((unsigned char*)-1 == video_buf) { + perror("mmap"); + return -1; + } + gb_frame = 0; + time_frame = gettime(); + + /* start to grab the first frame */ + gb_buf.frame = 1 - gb_frame; + gb_buf.height = height; + gb_buf.width = width; + gb_buf.format = VIDEO_PALETTE_YUV420P; + + if (ioctl(video_fd, VIDIOCMCAPTURE, &gb_buf) < 0) { + if (errno == EAGAIN) + fprintf(stderr,"Cannot Sync\n"); + else + perror("VIDIOCMCAPTURE"); + return -1; + } + use_mmap = 1; + return 0; +} + +/* test with read call and YUV422 stream */ +static int v4l_basic_read_picture(UINT8 *picture[3], + int width, int height, + int picture_number) +{ + int x, y; + UINT8 *p, *lum, *cb, *cr; + + if (read(video_fd, video_buf, width * height * 2) < 0) + perror("read"); + + picture[0] = picture_buf; + picture[1] = picture_buf + width * height; + picture[2] = picture_buf + (width * height) + (width * height) / 4; + + /* XXX: optimize */ + lum = picture[0]; + cb = picture[1]; + cr = picture[2]; + p = video_buf; + for(y=0;y<height;y+=2) { + for(x=0;x<width;x+=2) { + lum[0] = p[0]; + cb[0] = p[1]; + lum[1] = p[2]; + cr[0] = p[3]; + p += 4; + lum += 2; + cb++; + cr++; + } + for(x=0;x<width;x+=2) { + lum[0] = p[0]; + lum[1] = p[2]; + p += 4; + lum += 2; + } + } + return 0; +} + +static int v4l_mm_read_picture(UINT8 *picture[3], + int width, int height, + int picture_number) +{ + UINT8 *ptr; + int size; + long long curtime; + + /* wait based on the frame rate */ + time_frame += 1000000 / frame_rate; + do { + curtime = gettime(); + } while (curtime < time_frame); + + gb_buf.frame = gb_frame; + if (ioctl(video_fd, VIDIOCMCAPTURE, &gb_buf) < 0) { + if (errno == EAGAIN) + fprintf(stderr,"Cannot Sync\n"); + else + perror("VIDIOCMCAPTURE"); + return -1; + } + gb_frame = 1 - gb_frame; + + if (ioctl(video_fd, VIDIOCSYNC, &gb_frame) < 0) { + if (errno != EAGAIN) { + perror("VIDIOCSYNC"); + } + } + + size = width * height; + ptr = video_buf + gb_buffers.offsets[gb_frame]; + picture[0] = ptr; + picture[1] = ptr + size; + picture[2] = ptr + size + (size / 4); + + return 0; +} + +int v4l_read_picture(UINT8 *picture[3], + int width, int height, + int picture_number) +{ + if (use_mmap) { + return v4l_mm_read_picture(picture, width, height, picture_number); + } else { + return v4l_basic_read_picture(picture, width, height, picture_number); + } +} + +/* open audio device */ +int audio_open(int freq, int channels) +{ + int audio_fd, tmp, err; + + audio_fd = open("/dev/dsp",O_RDONLY); + if (audio_fd == -1) { + perror("/dev/dsp"); + return -1; + } + /* non blocking mode */ + fcntl(audio_fd, F_SETFL, O_NONBLOCK); + +#if 0 + tmp=(NB_FRAGMENTS << 16) | FRAGMENT_BITS; + err=ioctl(audio_fd, SNDCTL_DSP_SETFRAGMENT, &tmp); + if (err < 0) { + perror("SNDCTL_DSP_SETFRAGMENT"); + } +#endif + + /* always set to this size */ + /* XXX: incorrect if big endian */ + tmp=AFMT_S16_LE; + err=ioctl(audio_fd,SNDCTL_DSP_SETFMT,&tmp); + if (err < 0) { + perror("SNDCTL_DSP_SETFMT"); + } + + tmp= (channels == 2); + err=ioctl(audio_fd,SNDCTL_DSP_STEREO,&tmp); + if (err < 0) { + perror("SNDCTL_DSP_STEREO"); + } + + /* should be last */ + tmp = freq; + err=ioctl(audio_fd, SNDCTL_DSP_SPEED, &tmp); + if (err < 0) { + perror("SNDCTL_DSP_SPEED"); + } + return audio_fd; +} + |