static int query_formats(AVFilterContext *ctx) { AVFilterFormats *formats = NULL; int fmt; for (fmt = 0; fmt < AV_PIX_FMT_NB; fmt++) { const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(fmt); if (!(desc->flags & PIX_FMT_PAL || fmt == AV_PIX_FMT_NV21 || fmt == AV_PIX_FMT_NV12)) ff_add_format(&formats, fmt); } ff_set_common_formats(ctx, formats); return 0; }