EXR codec

[Antoine Martin]

Now that we have support for 10-bit per channel in both the server (#909) and the client (#1309), 10-bit video encoding is planned (#1308 for nvenc, #1310 for vpx) so it makes sense to also support a 10-bit non-video compression format. See also #784 for BPG.

EXR also supports stereo modes (#1316) and could potentially help us replace PNG with something faster / better? The list of ​Compression methods is not particularly impressive: RLE and ZIP for lossless!

Both openexr and jxrlib have mingw64 ports already.

Links:

• ​jxrlib: open source implementation of jpegxr - hosted on codeplex (yuk - doesn't work properly), they have EXE files in their repository! (WTH!) no documentation, not maintained?
• ​openexr: OpenEXR is a high dynamic-range (HDR) image file format developed by Industrial Light & Magic for use in computer imaging applications., some documentation here: ​Reading and Writing OpenEXR Image Files with the IlmImf Library - though this uses file or mmap IO... PITA.

[Antoine Martin]

Milestone renamed