renderer: switch to hermite downscaling by default

Scores higher on perceptual metrics and is much faster to compute than mitchell, especially since it has no negative weights.
haasn · Sep 19, 2023 · 75b3947 · 75b3947
1 parent 037c44e
commit 75b3947
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Showing 2 changed files with 5 additions and 5 deletions.
diff --git a/src/renderer.c b/src/renderer.c
@@ -201,7 +201,7 @@ const struct pl_render_params pl_render_fast_params = { PL_RENDER_DEFAULTS };
 const struct pl_render_params pl_render_default_params = {
     PL_RENDER_DEFAULTS
     .upscaler           = &pl_filter_spline36,
-    .downscaler         = &pl_filter_mitchell,
+    .downscaler         = &pl_filter_hermite,
     .frame_mixer        = &pl_filter_oversample,
     .sigmoid_params     = &pl_sigmoid_default_params,
     .dither_params      = &pl_dither_default_params,
@@ -211,7 +211,7 @@ const struct pl_render_params pl_render_default_params = {
 const struct pl_render_params pl_render_high_quality_params = {
     PL_RENDER_DEFAULTS
     .upscaler           = &pl_filter_ewa_lanczossharp,
-    .downscaler         = &pl_filter_mitchell,
+    .downscaler         = &pl_filter_hermite,
     .frame_mixer        = &pl_filter_hermite,
     .sigmoid_params     = &pl_sigmoid_default_params,
     .peak_detect_params = &pl_peak_detect_high_quality_params,

diff --git a/src/tests/options.c b/src/tests/options.c
@@ -29,7 +29,7 @@ int main()
     REQUIRE(pl_options_load(test, "preset=fast"));
     REQUIRE_STREQ(pl_options_save(test), "");
 
-    const char *def_opts = "upscaler=spline36,downscaler=mitchell,frame_mixer=oversample,sigmoid=yes,peak_detect=yes,dither=yes";
+    const char *def_opts = "upscaler=spline36,downscaler=hermite,frame_mixer=oversample,sigmoid=yes,peak_detect=yes,dither=yes";
     pl_options_reset(test, &pl_render_default_params);
     REQUIRE_STREQ(pl_options_save(test), def_opts);
     struct pl_options_t def_pre = *test;
@@ -53,9 +53,9 @@ int main()
     REQUIRE_CMP(*(int *) data->value, =, pl_render_default_params.lut_entries, "d");
     REQUIRE_STREQ(data->text, "64");
 
-    const char *hq_opts = "upscaler=ewa_lanczossharp,downscaler=mitchell,frame_mixer=hermite,deband=yes,sigmoid=yes,peak_detect=yes,peak_percentile=99.99500274658203,contrast_recovery=0.30000001192092896,dither=yes";
+    const char *hq_opts = "upscaler=ewa_lanczossharp,downscaler=hermite,frame_mixer=hermite,deband=yes,sigmoid=yes,peak_detect=yes,peak_percentile=99.99500274658203,contrast_recovery=0.30000001192092896,dither=yes";
     // fallback can produce different precision
-    const char *hq_opts2 = "upscaler=ewa_lanczossharp,downscaler=mitchell,frame_mixer=hermite,deband=yes,sigmoid=yes,peak_detect=yes,peak_percentile=99.99500274658203125,contrast_recovery=0.30000001192092896,dither=yes";
+    const char *hq_opts2 = "upscaler=ewa_lanczossharp,downscaler=hermite,frame_mixer=hermite,deband=yes,sigmoid=yes,peak_detect=yes,peak_percentile=99.99500274658203125,contrast_recovery=0.30000001192092896,dither=yes";
 
     pl_options_reset(test, &pl_render_high_quality_params);
     const char *opts = pl_options_save(test);