int ff_avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx) { int ret; /* find supported formats from sub-filters, and merge along links */ if ((ret = query_formats(graph, log_ctx)) < 0) return ret; /* Once everything is merged, it's possible that we'll still have * multiple valid media format choices. We pick the first one. */ pick_formats(graph); return 0; }