diff --git a/src/media/media_stream.h b/src/media/media_stream.h
index 747f3ea1894c895ee2ed5dd3dfee23c6ec0fb0dd..026c5f1ad46a679fc01390156baa852e8e8a57fa 100644
--- a/src/media/media_stream.h
+++ b/src/media/media_stream.h
@@ -126,6 +126,7 @@ struct MediaStream {
         } else {
             sampleRate = f->sample_rate;
             nbChannels = f->channels;
+            timeBase = rational<int>(1, f->sample_rate);
         }
     }
 };