diff --git a/libmpcodecs/ae_lavc.c b/libmpcodecs/ae_lavc.c
index b31eb62fce..3b07d6a963 100644
--- a/libmpcodecs/ae_lavc.c
+++ b/libmpcodecs/ae_lavc.c
@@ -206,6 +206,8 @@ int mpae_init_lavc(audio_encoder_t *encoder)
 	// put sample parameters
 	lavc_actx->channels = encoder->params.channels;
 	lavc_actx->sample_rate = encoder->params.sample_rate;
+	lavc_actx->time_base.num = 1;
+	lavc_actx->time_base.den = encoder->params.sample_rate;
         if(lavc_param_abitrate<1000)
                 lavc_actx->bit_rate = encoder->params.bitrate = lavc_param_abitrate * 1000;
         else