vo_gpu: default to dscale=hermite

This new filter is slightly sharper, and significantly faster, than
mitchell. It also tends to preserve detail better. All in all, there is
no reason not to use it by default, especially from a performance PoV.
(In vo_gpu_next, hermite is implemented efficiently using hardware
accelerated bilinear interpolation)

See-Also: https://code.videolan.org/videolan/libplacebo/-/commit/75b3947b2c07803456483ec6976c037bad91b5dd

DOCS/interface-changes.rst

@@ -68,6 +68,7 @@ Interface changes
     - change `--tscale` default to `oversample`
     - change `--dither-depth` to `auto`
     - deprecate `--profile=gpu-hq`, add `--profile=<fast|high-quality>`
+    - change `--dscale` default to `hermite`
  --- mpv 0.36.0 ---
     - add `--target-contrast`
     - Target luminance value is now also applied when ICC profile is used.

DOCS/man/options.rst

@@ -5282,13 +5282,13 @@ them.
 
     ``mitchell``
         Mitchell-Netravali. The ``B`` and ``C`` parameters can be set with
-        ``--scale-param1`` and ``--scale-param2``. This is the default for
-        ``--dscale``.
+        ``--scale-param1`` and ``--scale-param2``.
 
     ``hermite``
         Hermite spline. Similar to ``bicubic`` but with ``B`` set to ``0.0``.
         This filter has the special property of having a support of radius 1.0,
-        making it very fast in comparison, but prone to blocking.
+        making it very fast in comparison, but prone to blocking. This is the
+        default for ``--dscale``.
 
     ``catmull_rom``
         Catmull-Rom. A Cubic filter in the same vein as ``mitchell``, where

video/out/gpu/video.c

@@ -304,7 +304,7 @@ static const struct gl_video_opts gl_video_opts_def = {
     .scaler = {
         {{"lanczos", .params={NAN, NAN}}, {.params = {NAN, NAN}},
          .cutoff = 0.001}, // scale
-        {{"mitchell", .params={NAN, NAN}}, {.params = {NAN, NAN}},
+        {{"hermite", .params={NAN, NAN}}, {.params = {NAN, NAN}},
          .cutoff = 0.001}, // dscale
         {{NULL, .params={NAN, NAN}}, {.params = {NAN, NAN}},
          .cutoff = 0.001}, // cscale