static int create_filter(AVFilterContext **filt_ctx, AVFilterGraph *ctx, int index, const char *filt_name, const char *args, void *log_ctx) { AVFilter *filt; char inst_name[30]; char tmp_args[256]; int ret; snprintf(inst_name, sizeof(inst_name), "Parsed_%s_%d", filt_name, index); filt = avfilter_get_by_name(filt_name); if (!filt) { av_log(log_ctx, AV_LOG_ERROR, "No such filter: '%s'\n", filt_name); return AVERROR(EINVAL); } *filt_ctx = avfilter_graph_alloc_filter(ctx, filt, inst_name); if (!*filt_ctx) { av_log(log_ctx, AV_LOG_ERROR, "Error creating filter '%s'\n", filt_name); return AVERROR(ENOMEM); } if (!strcmp(filt_name, "scale") && args && !strstr(args, "flags") && ctx->scale_sws_opts) { snprintf(tmp_args, sizeof(tmp_args), "%s:%s", args, ctx->scale_sws_opts); args = tmp_args; } ret = avfilter_init_str(*filt_ctx, args); if (ret < 0) { av_log(log_ctx, AV_LOG_ERROR, "Error initializing filter '%s'", filt_name); if (args) av_log(log_ctx, AV_LOG_ERROR, " with args '%s'", args); av_log(log_ctx, AV_LOG_ERROR, "\n"); return ret; } return 0; }