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-rw-r--r--libav/grab.c321
1 files changed, 321 insertions, 0 deletions
diff --git a/libav/grab.c b/libav/grab.c
new file mode 100644
index 0000000000..f92cc397e6
--- /dev/null
+++ b/libav/grab.c
@@ -0,0 +1,321 @@
+/*
+ * Linux video grab interface
+ * Copyright (c) 2000,2001 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 <string.h>
+#include <linux/videodev.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <errno.h>
+#include <sys/time.h>
+
+#include "avformat.h"
+
+typedef struct {
+ int fd;
+ int frame_format; /* see VIDEO_PALETTE_xxx */
+ int use_mmap;
+ int width, height;
+ float rate;
+ INT64 time_frame;
+} VideoData;
+
+const char *v4l_device = "/dev/video";
+
+/* XXX: move all that to the context */
+
+static struct video_capability video_cap;
+static UINT8 *video_buf;
+static struct video_mbuf gb_buffers;
+static struct video_mmap gb_buf;
+static struct video_audio audio;
+static int gb_frame = 0;
+
+static int v4l_init(URLContext *h)
+{
+ VideoData *s = h->priv_data;
+ int width, height;
+ int ret;
+ int video_fd, frame_size;
+
+ width = s->width;
+ height = s->height;
+
+ video_fd = open(v4l_device, O_RDWR);
+ if (video_fd < 0) {
+ perror(v4l_device);
+ return -EIO;
+ }
+
+ if (ioctl(video_fd,VIDIOCGCAP,&video_cap) < 0) {
+ perror("VIDIOCGCAP");
+ goto fail;
+ }
+
+ if (!(video_cap.type & VID_TYPE_CAPTURE)) {
+ fprintf(stderr, "Fatal: grab device does not handle capture\n");
+ goto fail;
+ }
+
+ /* unmute audio */
+ ioctl(video_fd, VIDIOCGAUDIO, &audio);
+ audio.flags &= ~VIDEO_AUDIO_MUTE;
+ ioctl(video_fd, VIDIOCSAUDIO, &audio);
+
+ ret = ioctl(video_fd,VIDIOCGMBUF,&gb_buffers);
+ if (ret < 0) {
+ /* try to use read based access */
+ struct video_window win;
+ struct video_picture pict;
+ 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);
+
+ 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=VIDEO_PALETTE_YUV420P;
+ ret = ioctl(video_fd, VIDIOCSPICT, &pict);
+ if (ret < 0) {
+ pict.palette=VIDEO_PALETTE_YUV422;
+ ret = ioctl(video_fd, VIDIOCSPICT, &pict);
+ if (ret < 0) {
+ pict.palette=VIDEO_PALETTE_RGB24;
+ ret = ioctl(video_fd, VIDIOCSPICT, &pict);
+ if (ret < 0)
+ goto fail1;
+ }
+ }
+
+ s->frame_format = pict.palette;
+
+ val = 1;
+ ioctl(video_fd, VIDIOCCAPTURE, &val);
+
+ s->time_frame = gettime();
+ s->use_mmap = 0;
+ } else {
+ video_buf = mmap(0,gb_buffers.size,PROT_READ|PROT_WRITE,MAP_SHARED,video_fd,0);
+ if ((unsigned char*)-1 == video_buf) {
+ perror("mmap");
+ goto fail;
+ }
+ gb_frame = 0;
+ s->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;
+
+ ret = ioctl(video_fd, VIDIOCMCAPTURE, &gb_buf);
+ if (ret < 0 && errno != EAGAIN) {
+ /* try YUV422 */
+ gb_buf.format = VIDEO_PALETTE_YUV422;
+
+ ret = ioctl(video_fd, VIDIOCMCAPTURE, &gb_buf);
+ if (ret < 0 && errno != EAGAIN) {
+ /* try RGB24 */
+ gb_buf.format = VIDEO_PALETTE_RGB24;
+ ret = ioctl(video_fd, VIDIOCMCAPTURE, &gb_buf);
+ }
+ }
+ if (ret < 0) {
+ if (errno != EAGAIN) {
+ fail1:
+ fprintf(stderr, "Fatal: grab device does not support suitable format\n");
+ } else {
+ fprintf(stderr,"Fatal: grab device does not receive any video signal\n");
+ }
+ goto fail;
+ }
+ s->frame_format = gb_buf.format;
+ s->use_mmap = 1;
+ }
+
+ switch(s->frame_format) {
+ case VIDEO_PALETTE_YUV420P:
+ frame_size = (width * height * 3) / 2;
+ break;
+ case VIDEO_PALETTE_YUV422:
+ frame_size = width * height * 2;
+ break;
+ case VIDEO_PALETTE_RGB24:
+ frame_size = width * height * 3;
+ break;
+ default:
+ goto fail;
+ }
+ s->fd = video_fd;
+ h->packet_size = frame_size;
+ return 0;
+ fail:
+ close(video_fd);
+ return -EIO;
+}
+
+static int v4l_mm_read_picture(URLContext *h, UINT8 *buf)
+{
+ VideoData *s = h->priv_data;
+ UINT8 *ptr;
+
+ gb_buf.frame = gb_frame;
+ if (ioctl(s->fd, VIDIOCMCAPTURE, &gb_buf) < 0) {
+ if (errno == EAGAIN)
+ fprintf(stderr,"Cannot Sync\n");
+ else
+ perror("VIDIOCMCAPTURE");
+ return -EIO;
+ }
+ gb_frame = 1 - gb_frame;
+
+ while (ioctl(s->fd, VIDIOCSYNC, &gb_frame) < 0 &&
+ (errno == EAGAIN || errno == EINTR));
+
+ ptr = video_buf + gb_buffers.offsets[gb_frame];
+ memcpy(buf, ptr, h->packet_size);
+ return h->packet_size;
+}
+
+/* note: we support only one picture read at a time */
+static int video_read(URLContext *h, UINT8 *buf, int size)
+{
+ VideoData *s = h->priv_data;
+ INT64 curtime;
+
+ if (size != h->packet_size)
+ return -EINVAL;
+
+ /* wait based on the frame rate */
+ s->time_frame += (int)(1000000 / s->rate);
+ do {
+ curtime = gettime();
+ } while (curtime < s->time_frame);
+
+ /* read one frame */
+ if (s->use_mmap) {
+ return v4l_mm_read_picture(h, buf);
+ } else {
+ if (read(s->fd, buf, size) != size)
+ return -EIO;
+ return h->packet_size;
+ }
+}
+
+static int video_get_format(URLContext *h, URLFormat *f)
+{
+ VideoData *s = h->priv_data;
+
+ f->width = s->width;
+ f->height = s->height;
+ f->frame_rate = (int)(s->rate * FRAME_RATE_BASE);
+ strcpy(f->format_name, "rawvideo");
+
+ switch(s->frame_format) {
+ case VIDEO_PALETTE_YUV420P:
+ f->pix_fmt = PIX_FMT_YUV420P;
+ break;
+ case VIDEO_PALETTE_YUV422:
+ f->pix_fmt = PIX_FMT_YUV422;
+ break;
+ case VIDEO_PALETTE_RGB24:
+ f->pix_fmt = PIX_FMT_BGR24; /* NOTE: v4l uses BGR24, not RGB24 ! */
+ break;
+ default:
+ abort();
+ }
+ return 0;
+}
+
+/* URI syntax: 'video:width,height,rate'
+ */
+static int video_open(URLContext *h, const char *uri, int flags)
+{
+ VideoData *s;
+ const char *p;
+ int width, height;
+ int ret;
+ float rate;
+
+ /* extract parameters */
+ p = uri;
+ strstart(p, "video:", &p);
+ width = strtol(p, (char **)&p, 0);
+ if (width <= 0)
+ return -EINVAL;
+ if (*p == ',')
+ p++;
+ height = strtol(p, (char **)&p, 0);
+ if (height <= 0)
+ return -EINVAL;
+ if (*p == ',')
+ p++;
+ rate = strtod(p, (char **)&p);
+ if (rate <= 0)
+ return -EINVAL;
+
+ s = malloc(sizeof(VideoData));
+ if (!s)
+ return -ENOMEM;
+ h->priv_data = s;
+ h->is_streamed = 1;
+ s->width = width;
+ s->height = height;
+ s->rate = rate;
+ ret = v4l_init(h);
+ if (ret)
+ free(s);
+ return ret;
+}
+
+static int video_close(URLContext *h)
+{
+ VideoData *s = h->priv_data;
+
+ close(s->fd);
+ free(s);
+ return 0;
+}
+
+URLProtocol video_protocol = {
+ "video",
+ video_open,
+ video_read,
+ NULL,
+ NULL, /* seek */
+ video_close,
+ video_get_format,
+};
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-01 01:37:34 +0000