[FFmpeg-devel] [PATCH 1/2] lavfi/avfiltergraph: suggest a solution when format selection fails.

[Nicolas George]

Format selection can fail if the channel layout is not known
but some filter do not support that.

Signed-off-by: Nicolas George <nicolas.george at normalesup.org>
---
 libavfilter/avfiltergraph.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavfilter/avfiltergraph.c b/libavfilter/avfiltergraph.c
index fb78a87..e0cb4aa 100644
--- a/libavfilter/avfiltergraph.c
+++ b/libavfilter/avfiltergraph.c
@@ -637,6 +637,10 @@ static int pick_format(AVFilterLink *link, AVFilterLink *ref)
             av_log(link->src, AV_LOG_ERROR, "Cannot select channel layout for"
                    " the link between filters %s and %s.\n", link->src->name,
                    link->dst->name);
+            if (!link->in_channel_layouts->all_counts)
+                av_log(link->src, AV_LOG_ERROR, "Unknown channel layouts not "
+                       "supported, try specifying a channel layout using "
+                       "'aformat=channel_layouts=something'.\n");
             return AVERROR(EINVAL);
         }
         link->in_channel_layouts->nb_channel_layouts = 1;
-- 
1.8.4.rc3