avfilter/buffersink: add av_buffersink_get_side_data()

This will be used to get global side data that was propagated through the
filterchain.

Signed-off-by: James Almer <jamrial@gmail.com>

doc/APIchanges

@@ -2,6 +2,9 @@ The last version increases of all libraries were on 2024-03-07
 
 API changes, most recent first:
 
+2025-01-25 - xxxxxxxxxx - lavfi 10.9.100 - buffersink.h
+  Add av_buffersink_get_side_data().
+
 2025-01-25 - xxxxxxxxxx - lavfi 10.8.100 - buffersrc.h
   Add AVBufferSrcParameters.side_data and AVBufferSrcParameters.nb_side_data
 

libavfilter/buffersink.c

@@ -364,6 +364,14 @@ int av_buffersink_get_ch_layout(const AVFilterContext *ctx, AVChannelLayout *out
     return 0;
 }
 
+const AVFrameSideData *const *av_buffersink_get_side_data(const AVFilterContext *ctx,
+                                                          int *nb_side_data)
+{
+    av_assert0(fffilter(ctx->filter)->activate == activate);
+    *nb_side_data = ctx->inputs[0]->nb_side_data;
+    return (const AVFrameSideData *const *)ctx->inputs[0]->side_data;
+}
+
 #if FF_API_BUFFERSINK_OPTS
 #define NB_ITEMS(list) (list ## _size / sizeof(*list))
 #endif

libavfilter/buffersink.h

@@ -48,6 +48,7 @@
  * - av_buffersink_get_channels(),
  * - av_buffersink_get_ch_layout(),
  * - av_buffersink_get_sample_rate().
+ * - av_buffersink_get_side_data().
  *
  * The layout returned by av_buffersink_get_ch_layout() must de uninitialized
  * by the caller.
@@ -122,6 +123,9 @@ int              av_buffersink_get_sample_rate         (const AVFilterContext *c
 
 AVBufferRef *    av_buffersink_get_hw_frames_ctx       (const AVFilterContext *ctx);
 
+const AVFrameSideData *const *av_buffersink_get_side_data(const AVFilterContext *ctx,
+                                                          int *nb_side_data);
+
 /** @} */
 
 /**

libavfilter/version.h

@@ -31,7 +31,7 @@
 
 #include "version_major.h"
 
-#define LIBAVFILTER_VERSION_MINOR   8
+#define LIBAVFILTER_VERSION_MINOR   9
 #define LIBAVFILTER_VERSION_MICRO 100