Original X11 device demuxer patch from Clemens Fruhwirth

- Build system integration is equivalent to RFC #6 patch
- Same rule applies to ffmpeg.c/allformats.[c|h]
- x11grab.c is from Clemens Fruhwirth except the x11 grab
  structure for libavformat registration is renamed to
    match build system integration.

Originally committed as revision 7302 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -1659,6 +1659,16 @@ int dummy = V4L2_PIX_FMT_YUV420;
 struct v4l2_buffer dummy1;
 EOF
 
+# Deal with the x11 frame grabber
+enabled gpl                             &&
+enabled x11_grab_device_demuxer         &&
+check_header X11/Xlib.h                 &&
+check_header X11/extensions/XShm.h      &&
+check_func XOpenDisplay -lX11           &&
+check_func XShmCreateImage -lX11 -lXext &&
+add_extralibs -lX11 -lXext              ||
+disable x11_grab_device_demuxer
+
 enabled debug && add_cflags -g
 
 # add some useful compiler flags if supported

ffmpeg.c

@@ -3234,6 +3234,10 @@ static void prepare_grab(void)
 
     if (has_video) {
         AVInputFormat *fmt1;
+#warning FIXME: find a better interface
+        if(!strncmp(video_device,"x11:",4)) {
+            video_grab_format="x11grab";
+        }
         fmt1 = av_find_input_format(video_grab_format);
         vp->device  = video_device;
         vp->channel = video_channel;

libavformat/Makefile

@@ -123,6 +123,7 @@ OBJS-$(CONFIG_WC3_DEMUXER)               += wc3movie.o
 OBJS-$(CONFIG_WSAUD_DEMUXER)             += westwood.o
 OBJS-$(CONFIG_WSVQA_DEMUXER)             += westwood.o
 OBJS-$(CONFIG_WV_DEMUXER)                += wv.o
+OBJS-$(CONFIG_X11_GRAB_DEVICE_DEMUXER)   += x11grab.o
 OBJS-$(CONFIG_YUV4MPEGPIPE_MUXER)        += yuv4mpeg.o
 OBJS-$(CONFIG_YUV4MPEGPIPE_DEMUXER)      += yuv4mpeg.o
 

libavformat/allformats.c

@@ -166,6 +166,7 @@ void av_register_all(void)
     REGISTER_DEMUXER (WSAUD, wsaud);
     REGISTER_DEMUXER (WSVQA, wsvqa);
     REGISTER_DEMUXER (WV, wv);
+    REGISTER_DEMUXER (X11_GRAB_DEVICE, x11_grab_device);
     REGISTER_MUXDEMUX(YUV4MPEGPIPE, yuv4mpegpipe);
 
 #ifdef CONFIG_PROTOCOLS

libavformat/allformats.h

@@ -163,6 +163,7 @@ extern AVInputFormat wv_demuxer;
 extern AVOutputFormat yuv4mpegpipe_muxer;
 extern AVInputFormat yuv4mpegpipe_demuxer;
 extern AVInputFormat tiertexseq_demuxer;
+extern AVInputFormat x11_grab_device_demuxer;
 
 /* raw.c */
 int pcm_read_seek(AVFormatContext *s,