avplay: Use the named syntax for buffersrc arguments

Avoid confusion.

avtools/avplay.c

@@ -1441,7 +1441,8 @@ static int configure_video_filters(AVFilterGraph *graph, PlayerState *is, const
     snprintf(sws_flags_str, sizeof(sws_flags_str), "flags=%"PRId64, sws_flags);
     graph->scale_sws_opts = av_strdup(sws_flags_str);
 
-    snprintf(buffersrc_args, sizeof(buffersrc_args), "%d:%d:%d:%d:%d:%d:%d",
+    snprintf(buffersrc_args, sizeof(buffersrc_args),
+             "width=%d:height=%d:pix_fmt=%d:time_base=%d/%d:sar=%d/%d",
              codec->width, codec->height, codec->pix_fmt,
              is->video_st->time_base.num, is->video_st->time_base.den,
              codec->sample_aspect_ratio.num, codec->sample_aspect_ratio.den);