avfilter/avfilter: Add avfilter_link_get_hw_frames_ctx()

Signed-off-by: softworkz <[email protected]>

Author: softworkz

doc/APIchanges

@@ -2,6 +2,9 @@ The last version increases of all libraries were on 2025-03-28
 
 API changes, most recent first:
 
+2025-02-xx - xxxxxxxxxx - lavfi 10.10.100 - avfilter.h
+  Add avfilter_link_get_hw_frames_ctx().
+
 2025-04-21 - xxxxxxxxxx - lavu 60.2.100 - log.h
   Add AV_CLASS_CATEGORY_HWDEVICE.
 

libavfilter/avfilter.c

@@ -989,6 +989,15 @@ enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx)
     return pads[pad_idx].type;
 }
 
+AVBufferRef *avfilter_link_get_hw_frames_ctx(AVFilterLink *link)
+{
+    FilterLink *plink = ff_filter_link(link);
+    if (plink->hw_frames_ctx)
+        return av_buffer_ref(plink->hw_frames_ctx);
+
+    return NULL;
+}
+
 static int default_filter_frame(AVFilterLink *link, AVFrame *frame)
 {
     return ff_filter_frame(link->dst->outputs[0], frame);

libavfilter/avfilter.h

@@ -96,6 +96,18 @@ const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx);
  */
 enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx);
 
+/**
+ * Get the hardware frames context of a filter link.
+ *
+ * @param link an AVFilterLink
+ *
+ * @return a ref-counted copy of the link's hw_frames_ctx field if there is
+ *         a hardware frames context associated with the link or NULL otherwise.
+ *         The returned AVBufferRef needs to be released with av_buffer_unref()
+ *         when it is no longer used.
+ */
+AVBufferRef* avfilter_link_get_hw_frames_ctx(AVFilterLink *link);
+
 /**
  * Lists of formats / etc. supported by an end of a link.
  *