From 9ace76697ac1e43aa4da4c7333ec4a296907c336 Mon Sep 17 00:00:00 2001
From: Nicolas George <george@nsup.org>
Date: Tue, 2 Jan 2018 14:50:59 +0100
Subject: [PATCH] lavfi/framesync: document frame ownership for dualinput.

---
 libavfilter/framesync.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavfilter/framesync.h b/libavfilter/framesync.h
index 9fdc4d1ae2..abf3bf552b 100644
--- a/libavfilter/framesync.h
+++ b/libavfilter/framesync.h
@@ -286,6 +286,9 @@ int ff_framesync_init_dualinput(FFFrameSync *fs, AVFilterContext *parent);
  * @param f0  used to return the main frame
  * @param f1  used to return the second frame, or NULL if disabled
  * @return  >=0 for success or AVERROR code
+ * @note  The frame returned in f0 belongs to the caller (get = 1 in
+ * ff_framesync_get_frame()) while the frame returned in f1 is still owned
+ * by the framesync structure.
  */
 int ff_framesync_dualinput_get(FFFrameSync *fs, AVFrame **f0, AVFrame **f1);