avfilter/vf_scale_npp: select cubic and lanczos as alternative where...

avfilter/vf_scale_npp: select cubic and lanczos as alternative where super-sampling is not supported
Signed-off-by: Timo Rothenpieler <timo@rothenpieler.org>

libavfilter/vf_scale_npp.c

@@ -294,9 +294,21 @@ static int init_processing_chain(AVFilterContext *ctx, int in_width, int in_heig
 
     /* figure out which stages need to be done */
     if (in_width != out_width || in_height != out_height ||
-        in_deinterleaved_format != out_deinterleaved_format)
+        in_deinterleaved_format != out_deinterleaved_format) {
         s->stages[STAGE_RESIZE].stage_needed = 1;
 
+        if (s->interp_algo == NPPI_INTER_SUPER &&
+            (out_width > in_width && out_height > in_height)) {
+            s->interp_algo = NPPI_INTER_LANCZOS;
+            av_log(ctx, AV_LOG_WARNING, "super-sampling not supported for output dimensions, using lanczos instead.\n");
+        }
+        if (s->interp_algo == NPPI_INTER_SUPER &&
+            !(out_width < in_width && out_height < in_height)) {
+            s->interp_algo = NPPI_INTER_CUBIC;
+            av_log(ctx, AV_LOG_WARNING, "super-sampling not supported for output dimensions, using cubic instead.\n");
+        }
+    }
+
     if (!s->stages[STAGE_RESIZE].stage_needed && in_format == out_format)
         s->passthrough = 1;