Add SampleGridModel

vskernels/__init__.py

@@ -1,4 +1,5 @@
 from . import exceptions, kernels, util  # noqa: F401, F403
 from .exceptions import *  # noqa: F401, F403
 from .kernels import *  # noqa: F401, F403
+from .types import *  # noqa: F401, F403
 from .util import *  # noqa: F401, F403

vskernels/kernels/abstract.py

@@ -14,7 +14,10 @@
 from vstools.enums.color import _norm_props_enums
 
 from ..exceptions import UnknownDescalerError, UnknownKernelError, UnknownResamplerError, UnknownScalerError
-from ..types import BotFieldLeftShift, BotFieldTopShift, LeftShift, TopFieldLeftShift, TopFieldTopShift, TopShift
+from ..types import (
+    BorderHandling, BotFieldLeftShift, BotFieldTopShift, LeftShift, SampleGridModel, TopFieldLeftShift,
+    TopFieldTopShift, TopShift
+)
 
 __all__ = [
     'Scaler', 'ScalerT',
@@ -134,8 +137,8 @@ def __init_subclass__(cls) -> None:
         if not _finished_loading_abstract:
             return
 
-        from .complex import CustomComplexKernel
         from ..util import abstract_kernels
+        from .complex import CustomComplexKernel
 
         if cls in abstract_kernels:
             return
@@ -272,25 +275,33 @@ def descale(  # type: ignore[override]
         shift: tuple[TopShift, LeftShift] | tuple[
             TopShift | tuple[TopFieldTopShift, BotFieldTopShift],
             LeftShift | tuple[TopFieldLeftShift, BotFieldLeftShift]
-        ] = (0, 0), **kwargs: Any
+        ] = (0, 0), *,
+        border_handling: BorderHandling = BorderHandling.MIRROR,
+        sample_grid_model: SampleGridModel = SampleGridModel.MATCH_EDGES,
+        field_based: FieldBased | None = None,
+        **kwargs: Any
     ) -> vs.VideoNode:
         width, height = self._wh_norm(clip, width, height)
 
         check_correct_subsampling(clip, width, height)
 
-        field_based = FieldBased.from_param_or_video(kwargs.pop('field_based', None), clip)
+        field_based = FieldBased.from_param_or_video(field_based, clip)
 
         clip, bits = expect_bits(clip, 32)
 
         de_base_args = (width, height // (1 + field_based.is_inter))
+        kwargs |= dict(border_handling=border_handling)
 
         if field_based.is_inter:
             shift_y, shift_x = tuple[tuple[float, float], ...](
                 sh if isinstance(sh, tuple) else (sh, sh) for sh in shift
             )
 
-            de_kwargs_tf = self.get_descale_args(clip, (shift_y[0], shift_x[0]), *de_base_args, **kwargs)
-            de_kwargs_bf = self.get_descale_args(clip, (shift_y[1], shift_x[1]), *de_base_args, **kwargs)
+            kwargs_tf, shift = sample_grid_model.for_descale(clip, width, height, (shift_y[0], shift_x[0]), **kwargs)
+            kwargs_bf, shift = sample_grid_model.for_descale(clip, width, height, (shift_y[1], shift_x[1]), **kwargs)
+
+            de_kwargs_tf = self.get_descale_args(clip, (shift_y[0], shift_x[0]), *de_base_args, **kwargs_tf)
+            de_kwargs_bf = self.get_descale_args(clip, (shift_y[1], shift_x[1]), *de_base_args, **kwargs_bf)
 
             if height % 2:
                 raise CustomIndexError('You can\'t descale to odd resolution when crossconverted!', self.descale)
@@ -311,6 +322,8 @@ def descale(  # type: ignore[override]
             if any(isinstance(sh, tuple) for sh in shift):
                 raise CustomValueError('You can\'t descale per-field when the input is progressive!', self.descale)
 
+            kwargs, shift = sample_grid_model.for_descale(clip, width, height, shift, **kwargs)  # type: ignore
+
             de_kwargs = self.get_descale_args(clip, shift, *de_base_args, **kwargs)  # type: ignore
 
             descaled = self.descale_function(clip, **_norm_props_enums(de_kwargs))

vskernels/kernels/complex.py

@@ -1,21 +1,18 @@
 from __future__ import annotations
 
-from functools import lru_cache
-from typing import TYPE_CHECKING, Any, SupportsFloat, TypeVar, Union, cast
 from math import ceil
+from typing import TYPE_CHECKING, Any, SupportsFloat, TypeVar, Union, cast
+
 from stgpytools import inject_kwargs_params
 from vstools import (
-    CustomIntEnum, Dar, KwargsT, Resolution, Sar, VSFunctionAllArgs, check_correct_subsampling, fallback, inject_self,
-    padder, vs
+    Dar, KwargsT, Resolution, Sar, VSFunctionAllArgs, check_correct_subsampling, fallback, inject_self, vs
 )
 
-from ..types import Center, LeftShift, Slope, TopShift
+from ..types import BorderHandling, Center, LeftShift, SampleGridModel, Slope, TopShift
 from .abstract import Descaler, Kernel, Resampler, Scaler
 from .custom import CustomKernel
 
 __all__ = [
-    'BorderHandling',
-
     'LinearScaler', 'LinearDescaler',
 
     'KeepArScaler',
@@ -30,37 +27,6 @@
 XarT = TypeVar('XarT', Sar, Dar)
 
 
-class BorderHandling(CustomIntEnum):
-    MIRROR = 0
-    ZERO = 1
-    REPEAT = 2
-
-    def prepare_clip(self, clip: vs.VideoNode, min_pad: int = 2) -> vs.VideoNode:
-        pad_w, pad_h = (
-            self.pad_amount(size, min_pad) for size in (clip.width, clip.height)
-        )
-
-        if pad_w == pad_h == 0:
-            return clip
-
-        args = (clip, pad_w, pad_w, pad_h, pad_h)
-
-        match self:
-            case BorderHandling.MIRROR:
-                return padder.MIRROR(*args)
-            case BorderHandling.ZERO:
-                return padder.COLOR(*args)
-            case BorderHandling.REPEAT:
-                return padder.REPEAT(*args)
-
-    @lru_cache
-    def pad_amount(self, size: int, min_amount: int = 2) -> int:
-        if self is BorderHandling.MIRROR:
-            return 0
-
-        return (((size + min_amount) + 7) & -8) - size
-
-
 def _from_param(cls: type[XarT], value: XarT | bool | float | None, fallback: XarT) -> XarT | None:
     if value is False:
         return fallback
@@ -214,6 +180,7 @@ def scale(  # type: ignore[override]
         self, clip: vs.VideoNode, width: int | None = None, height: int | None = None,
         shift: tuple[TopShift, LeftShift] = (0, 0), *,
         border_handling: BorderHandling = BorderHandling.MIRROR,
+        sample_grid_model: SampleGridModel = SampleGridModel.MATCH_EDGES,
         sar: Sar | float | bool | None = None, dar: Dar | float | bool | None = None,
         dar_in: Dar | bool | float | None = None, keep_ar: bool | None = None,
         **kwargs: Any
@@ -229,6 +196,8 @@ def scale(  # type: ignore[override]
 
             kwargs, shift, out_sar = self._handle_crop_resize_kwargs(clip, width, height, shift, **kwargs)
 
+            kwargs, shift = sample_grid_model.for_scale(clip, width, height, shift, **kwargs)
+
             padded = border_handling.prepare_clip(clip, self.kernel_radius)
 
             shift, clip = tuple(
@@ -251,6 +220,7 @@ def scale(  # type: ignore[override]
         shift: tuple[TopShift, LeftShift] = (0, 0),
         *,
         border_handling: BorderHandling = BorderHandling.MIRROR,
+        sample_grid_model: SampleGridModel = SampleGridModel.MATCH_EDGES,
         sar: Sar | bool | float | None = None, dar: Dar | bool | float | None = None, keep_ar: bool | None = None,
         linear: bool = False, sigmoid: bool | tuple[Slope, Center] = False,
         **kwargs: Any
@@ -259,7 +229,7 @@ def scale(  # type: ignore[override]
         return super().scale(
             clip, width, height, shift, sar=sar, dar=dar, keep_ar=keep_ar,
             linear=linear, sigmoid=sigmoid, border_handling=border_handling,
-            **kwargs
+            sample_grid_model=sample_grid_model, **kwargs
         )
 
 
@@ -273,8 +243,10 @@ class CustomComplexKernel(CustomKernel, ComplexKernel):  # type: ignore
         @inject_kwargs_params
         def descale(  # type: ignore[override]
             self, clip: vs.VideoNode, width: int, height: int, shift: tuple[TopShift, LeftShift] = (0, 0),
-            *, blur: float = 1.0, border_handling: BorderHandling, ignore_mask: vs.VideoNode | None = None,
-            linear: bool = False, sigmoid: bool | tuple[Slope, Center] = False, **kwargs: Any
+            *, blur: float = 1.0, border_handling: BorderHandling,
+            sample_grid_model: SampleGridModel = SampleGridModel.MATCH_EDGES,
+            ignore_mask: vs.VideoNode | None = None, linear: bool = False,
+            sigmoid: bool | tuple[Slope, Center] = False, **kwargs: Any
         ) -> vs.VideoNode:
             ...
 

vskernels/types.py

@@ -1,16 +1,83 @@
 from __future__ import annotations
 
-from typing import TypeAlias
+from functools import lru_cache
+from typing import Any, TypeAlias
+
+from vstools import CustomIntEnum, KwargsT, padder, vs
 
 __all__ = [
-    'TopShift',
-    'LeftShift',
-    'TopFieldTopShift',
-    'TopFieldLeftShift',
-    'BotFieldTopShift',
-    'BotFieldLeftShift',
+    'BorderHandling', 'SampleGridModel'
 ]
 
+
+class BorderHandling(CustomIntEnum):
+    MIRROR = 0
+    ZERO = 1
+    REPEAT = 2
+
+    def prepare_clip(self, clip: vs.VideoNode, min_pad: int = 2) -> vs.VideoNode:
+        pad_w, pad_h = (
+            self.pad_amount(size, min_pad) for size in (clip.width, clip.height)
+        )
+
+        if pad_w == pad_h == 0:
+            return clip
+
+        args = (clip, pad_w, pad_w, pad_h, pad_h)
+
+        match self:
+            case BorderHandling.MIRROR:
+                return padder.MIRROR(*args)
+            case BorderHandling.ZERO:
+                return padder.COLOR(*args)
+            case BorderHandling.REPEAT:
+                return padder.REPEAT(*args)
+
+    @lru_cache
+    def pad_amount(self, size: int, min_amount: int = 2) -> int:
+        if self is BorderHandling.MIRROR:
+            return 0
+
+        return (((size + min_amount) + 7) & -8) - size
+
+
+class SampleGridModel(CustomIntEnum):
+    MATCH_EDGES = 0
+    MATCH_CENTERS = 1
+
+    def __call__(
+        self, width: int, height: int, src_width: int, src_height: int, shift: tuple[float, float]
+    ) -> tuple[KwargsT, tuple[float, float]]:
+        kwargs = KwargsT()
+
+        if self is SampleGridModel.MATCH_CENTERS:
+            src_width = src_width * (width - 1) / (src_width - 1)
+            src_height = src_height * (height - 1) / (src_height - 1)
+
+            kwargs |= dict(src_width=src_width, src_height=src_height)
+            shift = tuple[float, float](
+                (x / 2 + y for x, y in zip(((height - src_height), (width - src_width)), shift))
+            )
+
+        return kwargs, shift
+
+    def for_scale(
+        self, clip: vs.VideoNode, width: int, height: int, shift: tuple[float, float], **kwargs: Any
+    ) -> tuple[KwargsT, tuple[float, float]]:
+        src_width = kwargs.pop('src_width', width)
+        src_height = kwargs.pop('src_height', height)
+
+        return self(src_width, src_height, width, height, shift)
+
+    def for_descale(
+        self, clip: vs.VideoNode, width: int, height: int, shift: tuple[float, float], **kwargs: Any
+    ) -> tuple[KwargsT, tuple[float, float]]:
+        src_width = kwargs.pop('src_width', clip.width)
+        src_height = kwargs.pop('src_height', clip.height)
+
+        return self(width, height, src_width, src_height, shift)
+
+
 TopShift: TypeAlias = float
 LeftShift: TypeAlias = float
 TopFieldTopShift: TypeAlias = float