lavfi: add a frame_rate field to AVFilterLink.

(cherry picked from ffmpeg commit 7b42036b3b23c85f473bf9369e37fa8da22eaf93)

Signed-off-by: Anton Khirnov <anton@khirnov.net>

1 files changed, 12 insertions, 0 deletions

diff --git a/libavfilter/avfilter.h b/libavfilter/avfilter.h
index 9dbfeea9eb..18908583a2 100644
--- a/libavfilter/avfilter.h
+++ b/libavfilter/avfilter.h
@@ -375,6 +375,18 @@ struct AVFilterLink {
         AVLINK_STARTINIT,       ///< started, but incomplete
         AVLINK_INIT             ///< complete
     } init_state;
+
+    /**
+     * Frame rate of the stream on the link, or 1/0 if unknown or variable;
+     * if left to 0/0, will be automatically copied from the first input
+     * of the source filter if it exists.
+     *
+     * Sources should set it to the real constant frame rate.
+     * If the source frame rate is unknown or variable, set this to 1/0.
+     * Filters should update it if necessary depending on their function.
+     * Sinks can use it to set a default output frame rate.
+     */
+    AVRational frame_rate;
 };
 
 /**