lavfi: add avfilter_link_free() function

Allow to free the buffers cached in each AVFilterLink pool.
Fix leak.

doc/APIchanges

@@ -13,6 +13,9 @@ libavutil:   2011-04-18
 
 API changes, most recent first:
 
+2011-06-03 - xxxxxx - lavfi 2.12.0 - avfilter_link_free()
+  Add avfilter_link_free() function.
+
 2011-05-28 - xxxxxx - lavu 51.3.0 - pixdesc.h
   Add av_get_pix_fmt_name() in libavutil/pixdesc.h, and deprecate
   avcodec_get_pix_fmt_name() in libavcodec/avcodec.h in its favor.

libavfilter/avfilter.c

@@ -165,6 +165,31 @@ int avfilter_link(AVFilterContext *src, unsigned srcpad,
     return 0;
 }
 
+void avfilter_link_free(AVFilterLink **link)
+{
+    if (!*link)
+        return;
+
+    if ((*link)->pool) {
+        int i;
+        for (i = 0; i < POOL_SIZE; i++) {
+            if ((*link)->pool->pic[i]) {
+                AVFilterBufferRef *picref = (*link)->pool->pic[i];
+                /* free buffer: picrefs stored in the pool are not
+                 * supposed to contain a free callback */
+                av_freep(&picref->buf->data[0]);
+                av_freep(&picref->buf);
+
+                av_freep(&picref->audio);
+                av_freep(&picref->video);
+                av_freep(&picref);
+            }
+        }
+        av_freep(&(*link)->pool);
+    }
+    av_freep(link);
+}
+
 int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
                            unsigned filt_srcpad_idx, unsigned filt_dstpad_idx)
 {
@@ -683,7 +708,7 @@ void avfilter_free(AVFilterContext *filter)
             avfilter_formats_unref(&link->in_formats);
             avfilter_formats_unref(&link->out_formats);
         }
-        av_freep(&link);
+        avfilter_link_free(&link);
     }
     for (i = 0; i < filter->output_count; i++) {
         if ((link = filter->outputs[i])) {
@@ -692,7 +717,7 @@ void avfilter_free(AVFilterContext *filter)
             avfilter_formats_unref(&link->in_formats);
             avfilter_formats_unref(&link->out_formats);
         }
-        av_freep(&link);
+        avfilter_link_free(&link);
     }
 
     av_freep(&filter->name);

libavfilter/avfilter.h

@@ -26,7 +26,7 @@
 #include "libavutil/samplefmt.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  2
-#define LIBAVFILTER_VERSION_MINOR 11
+#define LIBAVFILTER_VERSION_MINOR 12
 #define LIBAVFILTER_VERSION_MICRO  0
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
@@ -635,6 +635,11 @@ struct AVFilterLink {
 int avfilter_link(AVFilterContext *src, unsigned srcpad,
                   AVFilterContext *dst, unsigned dstpad);
 
+/**
+ * Free the link in *link, and set its pointer to NULL.
+ */
+void avfilter_link_free(AVFilterLink **link);
+
 /**
  * Negotiate the media format, dimensions, etc of all inputs to a filter.
  *