Make avfilter_get_video_buffer() recursive.

When called on a link with a filter whose destination pad has not a
get_video_buffer callback defined, it will call
avfilter_get_video_buffer() on the first output link of the
destination filer, rather than use avfilter_default_get_buffer(), so
the video buffer can be allocated forward in the filterchain.

Also add the w and h parameters to avfilter_get_video_buffer(), as the
minimum width and height requested by each filter in the filterchain
may change, this allows for example a memcpy-less pad filter.

This change breaks API / ABI backward compatibility.

See the thread:
"[PATCH] Implement recusive avfilter_get_video_buffer()".

Originally committed as revision 20272 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 4 insertions, 4 deletions

diff --git a/libavfilter/defaults.c b/libavfilter/defaults.c
index dabb1d5bf0..1983672cd6 100644
--- a/libavfilter/defaults.c
+++ b/libavfilter/defaults.c
@@ -32,7 +32,7 @@ void avfilter_default_free_video_buffer(AVFilterPic *pic)
 /* TODO: set the buffer's priv member to a context structure for the whole
  * filter chain.  This will allow for a buffer pool instead of the constant
  * alloc & free cycle currently implemented. */
-AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link, int perms)
+AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link, int perms, int w, int h)
 {
     AVFilterPic *pic = av_mallocz(sizeof(AVFilterPic));
     AVFilterPicRef *ref = av_mallocz(sizeof(AVFilterPicRef));
@@ -40,8 +40,8 @@ AVFilterPicRef *avfilter_default_get_video_buffer(AVFilterLink *link, int perms)
     char *buf;
 
     ref->pic   = pic;
-    ref->w     = pic->w = link->w;
-    ref->h     = pic->h = link->h;
+    ref->w     = pic->w = w;
+    ref->h     = pic->h = h;
 
     /* make sure the buffer gets read permission or it's useless for output */
     ref->perms = perms | AV_PERM_READ;
@@ -72,7 +72,7 @@ void avfilter_default_start_frame(AVFilterLink *link, AVFilterPicRef *picref)
         out = link->dst->outputs[0];
 
     if(out) {
-        out->outpic      = avfilter_get_video_buffer(out, AV_PERM_WRITE);
+        out->outpic      = avfilter_get_video_buffer(out, AV_PERM_WRITE, link->w, link->h);
         out->outpic->pts = picref->pts;
         avfilter_start_frame(out, avfilter_ref_pic(out->outpic, ~0));
     }