Basic mosaic, video blending modules

 * picture.c picture.h : vout that copies the rendered image in a libvlc
                         object.
 * mosaic.c : sub filter that takes all the images created by the picture
              module and blends them over the current video

I think i still have loads of things to fix (like memleaks)

Simple vlm configuration file to see this work :
<<<<
new chan1 broadcast enabled
setup chan1 input somevideo1.avi
setup chan1 option vout=picture

new chan2 broadcast enabled
setup chan2 input somevideo2.avi
setup chan2 option vout=picture

new bg broadcast enabled
setup bg input somevideo0.avi
setup bg option sub-filter=mosaic

control bg play
control chan1 play
control chan2 play
>>>>

You just have to launch : ./vlc -I telnet --vlm-conf vlm.conf

configure.ac

@@ -986,6 +986,7 @@ VLC_ADD_PLUGINS([aout_file equalizer])
 VLC_ADD_PLUGINS([i420_rgb i420_yuy2 i422_yuy2 i420_ymga])
 VLC_ADD_PLUGINS([id3 playlist export sgimb m3u xtag])
 VLC_ADD_PLUGINS([rawvideo blend scale image logo])
+VLC_ADD_PLUGINS([picture mosaic])
 VLC_ADD_PLUGINS([wav araw subtitle vobsub adpcm a52sys dtssys au])
 VLC_ADD_PLUGINS([access_file access_udp access_tcp access_http access_mms])
 VLC_ADD_PLUGINS([access_ftp ipv4])

modules/video_filter/Modules.am

+SOURCES_mosaic = mosaic.c
 SOURCES_transform = transform.c
 SOURCES_invert = invert.c
 SOURCES_adjust = adjust.c

modules/video_output/Modules.am

@@ -12,3 +12,4 @@ SOURCES_hd1000v = hd1000v.cpp
 SOURCES_snapshot = snapshot.c
 SOURCES_opengl = opengl.c
 SOURCES_image = image.c
+SOURCES_picture = picture.c

modules/video_output/picture.h

+#ifndef _PICTURE_VOUT_H
+#define _PICTURE_VOUT_H 1
+
+#define PICTURE_VOUT_E_AVAILABLE 0
+#define PICTURE_VOUT_E_OCCUPIED 1
+struct picture_vout_e_t {
+    picture_t *p_picture;
+    int i_status;
+};
+struct picture_vout_t
+{
+    vlc_mutex_t lock;
+    int i_picture_num;
+    struct picture_vout_e_t *p_pic;
+};
+
+#endif