lavfi/avf_concat: use av_make_q.

libavfilter/avf_concat.c

@@ -174,7 +174,7 @@ static int push_frame(AVFilterContext *ctx, unsigned in_no, AVFrame *buf)
     if (inlink->sample_rate)
         /* use number of audio samples */
         in->pts += av_rescale_q(buf->nb_samples,
-                                (AVRational){ 1, inlink->sample_rate },
+                                av_make_q(1, inlink->sample_rate),
                                 outlink->time_base);
     else if (in->nb_frames >= 2)
         /* use mean duration */