diff --git a/libavcodec/encode.c b/libavcodec/encode.c
index 85b8e089dd..6ae47b736c 100644
--- a/libavcodec/encode.c
+++ b/libavcodec/encode.c
@@ -555,6 +555,9 @@ FF_DISABLE_DEPRECATION_WARNINGS
 FF_ENABLE_DEPRECATION_WARNINGS
 #endif
 
+    if (!avctx->bits_per_raw_sample)
+        avctx->bits_per_raw_sample = 8 * av_get_bytes_per_sample(avctx->sample_fmt);
+
     return 0;
 }