Add AviSynth+ plugin

AviSynth+ API V8 required

README.md

@@ -1,10 +1,12 @@
 # Descale
 
-VapourSynth plugin to undo upscaling.
+Video/Image filter to undo upscaling.
+
+Includes a VapourSynth and Avisynth+ plugin
 
 ## Usage
 
-The plugin itself supports every constant input format. If the format is subsampled, left-aligned chroma planes are always assumed.
+The VapourSynth plugin itself supports every constant input format. If the format is subsampled, left-aligned chroma planes are always assumed.
 The included python wrapper, contrary to using the plugin directly, doesn't descale the chroma planes but scales them normally with `Spline36`.
 
 ```
@@ -23,6 +25,8 @@ descale.Despline64(clip src, int width, int height, float src_left=0.0, float sr
 descale.Descale(clip src, int width, int height, str kernel, int taps=3, float b=0.0, float c=0.0, float src_left=0.0, float src_top=0.0, float src_width=width, float src_height=height, int opt=0)
 ```
 
+The AviSynth+ plugin is used similarly, but without the `descale` namespace.
+
 ## How does this work?
 
 Resampling can be described as `A x = b`.
@@ -33,7 +37,7 @@ To do this, we extend the equation with the transpose of A: `A' A x = A' b`.
 
 `A' A` is now a banded symmetrical m x m matrix and `A' b` is a vector with `m` elements.
 
-This enables us to use LDLT decomposition on `A' A` to get `LD L' = A' A`. LD and L are both triangular matrices.
+This enables us to use LDLT decomposition on `A' A` to get `LD L' = A' A`. `LD` and `L` are both triangular matrices.
 
 Then we solve `LD y = A' b` with forward substitution, and finally `L' x = y` with back substitution.
 
@@ -42,6 +46,9 @@ We now have the original vector `x`.
 
 ## Compilation
 
+By default only the VapourSynth plugin is compiled
+To build the Avisynth+ plugin, add `-Dlibtype=avisynth` or `-Dlibtype=both` to the meson command below.
+
 ### Linux
 
 ```

cross-mingw-x86_64.txt

@@ -1,5 +1,6 @@
 [binaries]
 c = 'x86_64-w64-mingw32-gcc'
+cpp = 'x86_64-w64-mingw32-g++'
 ar = 'x86_64-w64-mingw32-ar'
 strip = 'x86_64-w64-mingw32-strip'
 pkgconfig = 'x86_64-w64-mingw32-pkg-config'

include/descale.h

@@ -1,5 +1,5 @@
 /* 
- * Copyright © 2017-2021 Frechdachs <[email protected]>
+ * Copyright © 2021-2022 Frechdachs <[email protected]>
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the “Software”), to deal
@@ -51,14 +51,15 @@ typedef enum DescaleOpt
 } DescaleOpt;
 
 
+// Optional struct members should be initialized to 0 if not used
 typedef struct DescaleParams
 {
     enum DescaleMode mode;
-    int taps;
-    double param1;
-    double param2;
-    double shift;
-    double active_dim;
+    int taps;           // required if mode is LANCZOS
+    double param1;      // required if mode is BICUBIC
+    double param2;      // required if mode is BICUBIC
+    double shift;       // optional
+    double active_dim;  // always required; usually equal to dst_dim
 } DescaleParams;
 
 

meson.build

@@ -10,12 +10,22 @@ cc = meson.get_compiler('c')
 
 includedirs = ['include', 'src']
 
-sources = ['src/descale.c', 'src/vsplugin.c']
+sources = ['src/descale.c']
 
 libs = []
 
 deps = []
 
+libtype = get_option('libtype')
+
+if libtype in ['vapoursynth', 'both']
+    sources += ['src/vsplugin.c']
+endif
+
+if libtype in ['avisynth', 'both']
+    sources += ['src/avsplugin.c']
+endif
+
 # Don't require VS to be installed on Windows,
 # so we don't need to have VS fully installed
 # in our mingw environment. Just the header files
@@ -25,13 +35,25 @@ if host_machine.system() == 'windows'
     m_dep = cc.find_library('m', static: true, required: false)
     p_dep = cc.find_library('winpthread', static: true)
     deps += [m_dep, p_dep]
-    installdir = join_paths(get_option('libdir'), 'vapoursynth')
+    if libtype in ['avisynth', 'both']
+        deps += [cc.find_library('AviSynth', dirs: meson.current_source_dir())]
+    endif
+    if libtype in ['vapoursynth', 'both']  # I'm not sure if it is possible to install
+                                           # the _same_ file to multiple directories with meson
+        installdir = join_paths(get_option('libdir'), 'vapoursynth')
+    else
+        installdir = join_paths(get_option('libdir'), 'avisynth')
+    endif
 else
     m_dep = cc.find_library('m', required: false)
     p_dep = cc.find_library('pthread')
     vs = dependency('vapoursynth').partial_dependency(compile_args: true, includes: true)
     deps += [m_dep, p_dep, vs]
-    installdir = join_paths(vs.get_pkgconfig_variable('libdir'), 'vapoursynth')
+    if libtype in ['vapoursynth', 'both']
+        installdir = join_paths(vs.get_pkgconfig_variable('libdir'), 'vapoursynth')
+    else
+        installdir = join_paths(vs.get_pkgconfig_variable('libdir'), 'avisynth')
+    endif
 endif
 
 if host_machine.cpu_family().startswith('x86')

meson_options.txt

@@ -0,0 +1 @@
+option('libtype', type: 'combo', choices: ['vapoursynth', 'avisynth', 'both'], value: 'vapoursynth')