[FFmpeg-devel] [PATCH 1/2] lavfi: fix filter format negotiation loop.

[Nicolas George]

query_formats() returning EAGAIN is not considered a progress
in the format negotiation.

If the filter returns EAGAIN but did set some of its formats
lists, it could be considered a partial success and counted
as progress in the negotiation. Not counting it is not a
problem because it currently only happens in the first round,
where there will always be some progress on the other filters.

Signed-off-by: Nicolas George <nicolas.george at normalesup.org>
---
 libavfilter/avfiltergraph.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libavfilter/avfiltergraph.c b/libavfilter/avfiltergraph.c
index 582a870..860f1d8 100644
--- a/libavfilter/avfiltergraph.c
+++ b/libavfilter/avfiltergraph.c
@@ -333,7 +333,8 @@ static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
             ret = ff_default_query_formats(f);
         if (ret < 0 && ret != AVERROR(EAGAIN))
             return ret;
-        count_queried++;
+        /* note: EAGAIN could indicate a partial success, not counted yet */
+        count_queried += ret >= 0;
     }
 
     /* go through and merge as many format lists as possible */
-- 
1.7.10.4