Initial revision

Originally committed as revision 5 to svn://svn.ffmpeg.org/ffmpeg/trunk

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,
+};