in Transform_V1/vf_transform_v1.c [743:763]
static av_cold int init_dict(AVFilterContext *ctx, AVDictionary **opts)
{
TransformContext *s = ctx->priv;
if (s->size_str && (s->w_expr || s->h_expr)) {
av_log(ctx, AV_LOG_ERROR,
"Size and width/height expressions cannot be set at the same time.\n");
return AVERROR(EINVAL);
}
if (s->w_expr && !s->h_expr)
FFSWAP(char *, s->w_expr, s->size_str);
av_log(ctx, AV_LOG_VERBOSE, "w:%s h:%s\n",
s->w_expr, s->h_expr);
s->opts = *opts;
*opts = NULL;
return 0;
}