fmtconv r26

• matrix: fixed the output colorspace when using singleout.
• matrix: fixed the output colorspace when using a custom matrix. Thanks to vxzms for the report.
• matrix/Vapoursynth: _Matrix and _ColorSpace frame properties are actually deleted when a custom matrix is used or the final colorspace is unknown. Thanks to mysteryx93 for the report.
• resample: fixed empty custom impulse that could cause a crash.
• resample: added top-left chroma location.
• resample/Avisynth+: interlacing detection now uses the global stream information when the frame properties are not available.
• resample/Avisynth+: fixed the planes parameter.
• transfer: Linear light can now be display- or scene-referred. Added sceneref, lw, lws, lwd, lb, ambiant and deprecated blacklvl.
• transfer: By default, automatically matches the reference white levels for source and destination transfer curves. This may cause some backward incompatibilities. match parameter added.
• transfer: Removed the planes parameter introduced in r24 because planes are no longer independent of each other.
• transfer: debug provides information about the transfer operation and levels as a frame property.
• transfer: BT.470M characteristic is now a pure power curve, instead of a copy of the sRGB curve.
• transfer/Avisynth+: fixed flt + bits combination that was ignored. Thanks to DTL for the report.
• transfer/Avisynth+: fixed case sensitivity to transs and transd.
• transfer/Vapoursynth: fixed logceis and logceid that were missing from the function registration since their introduction in r23… Thanks to groucho86 for the report.
• Fixed compatibility with Avisynth+ 3.7.1.
• Avisynth+: fixed "RGBPxx" colorspace values that weren’t correctly interpreted as planar.