Switch from bilinear to eighttap_smooth for frame-level
downsampling at low resolutions (<= 320x240).
avgPSNR/SSIM metrics increase from ~0.5-2% (all clips positive gain),
for 2 and 3 spatial layer SVC, with 3 temporal layers.
Small/negligible increase in encoding time (< 1%).
Change-Id: I758472fc4fddd51d87f13c9d1a1cd4986ef5d41f
// averaging filter), use bilinear for now.
if (width * height <= 640 * 480) {
cpi->svc.downsample_filter_type[cpi->svc.spatial_layer_id] = BILINEAR;
+ // Use Eightap_smooth for low resolutions.
+ if (width * height <= 320 * 240)
+ cpi->svc.downsample_filter_type[cpi->svc.spatial_layer_id] =
+ EIGHTTAP_SMOOTH;
cpi->svc.downsample_filter_phase[cpi->svc.spatial_layer_id] = 8;
}