Filter SDK/AVISYNTH INTERFACE VERSION

AVISYNTH_INTERFACE_VERSION usage

The AVISYNTH_INTERFACE_VERSION describes the level of features available, both in the core avisynth.dll and the third party plugin.

For a plugin author it describes what the core IScriptEnvironment vtable contains.

• Version 1 is Avisynth 2.0
• Version 2 is Avisynth 2.5, with the vtable having members up to IScriptEnvironment::SetWorkingDir(const char * newdir)
• Version 3 is Avisynth 2.5.6, with the IScriptEnvironment vtable adding 3 new members ManageCache, PlanarChromaAlignment and SubframePlanar.
• Version 4 is reserved and does not apply to any Avisynth version. It's only significance is it greater then 3 and less then 5.
• Version 5 is Avisynth 2.6.0a1-a5, with the IScriptEnvironment vtable adding 3 more new members DeleteScriptEnvironment, ApplyMessage and GetAVSLinkage. Also with version 5 the core provides AVS_Linkage support for baked code replacement.
• Version 6 is Avisynth 2.6.0, with the IScriptEnvironment vtable adding one more new member GetVarDef. It also uses size_t for things that are memory sizes, ready for 64 bit port.

Through the IClip interface it is the authors responsibility to declare the level of support the plugin provides:

virtual int __stdcall IClip()::GetVersion() { return AVISYNTH_INTERFACE_VERSION; }

• Version 1 is Avisynth 2.0
• Version 2 and 3 are Avisynth 2.5, supporting YV12, YUY2, RGB32 and RGB24 colour spaces.
• Version 4 is reserved and does not apply to any Avisynth version. It's significance is it greater then 3 and less then 5.
• Version 5 and 6 are Avisynth 2.6, and the IClip interface must support this update:

# Plugins that do not implement the interface must always return zero.
virtual int __stdcall IClip::SetCacheHints(int cachehints,int frame_range);