int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags) { int i, r = AVERROR(ENOSYS); if(!graph) return r; if((flags & AVFILTER_CMD_FLAG_ONE) && !(flags & AVFILTER_CMD_FLAG_FAST)) { r=avfilter_graph_send_command(graph, target, cmd, arg, res, res_len, flags | AVFILTER_CMD_FLAG_FAST); if(r != AVERROR(ENOSYS)) return r; } if(res_len && res) res[0]= 0; for (i = 0; i < graph->filter_count; i++) { AVFilterContext *filter = graph->filters[i]; if(!strcmp(target, "all") || !strcmp(target, filter->name) || !strcmp(target, filter->filter->name)){ r = avfilter_process_command(filter, cmd, arg, res, res_len, flags); if(r != AVERROR(ENOSYS)) { if((flags & AVFILTER_CMD_FLAG_ONE) || r<0) return r; } } } return r; }