ffmpeg: only copy bits_per_sample from decoder when it remains valid

I.e. when the only filters that are applied do not modify the frame
data.

1 files changed, 3 insertions, 0 deletions

diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h
index c14eed5643..cc7ba9bdca 100644
--- a/fftools/ffmpeg.h
+++ b/fftools/ffmpeg.h
@@ -287,6 +287,9 @@ typedef struct FilterGraph {
 
     AVFilterGraph *graph;
     int reconfiguration;
+    // true when the filtergraph contains only meta filters
+    // that do not modify the frame data
+    int is_meta;
 
     InputFilter   **inputs;
     int          nb_inputs;