av_log(ctx, AV_LOG_DEBUG, "Filter_string: %s\n", ctx->filter_string);
ret = av_dict_parse_string(&filter_dict, ctx->filter_string, "@", "#", AV_DICT_MULTIKEY); // parse filter_name:all_filter_options
if (ret) {
av_log(ctx, AV_LOG_DEBUG, "Filter_string: %s\n", ctx->filter_string);
ret = av_dict_parse_string(&filter_dict, ctx->filter_string, "@", "#", AV_DICT_MULTIKEY); // parse filter_name:all_filter_options
if (ret) {