Re: [Openexr-devel] EXR texture memory overhead

[Karl Rasche]

But it's not optimal for a use pattern like TextureSystem where the typical request is ONE tile, and the next tile it wants may not even be adjacent.

Whoops. What I pointed at look like its only the case if you read through Imf::InputFile.  If you use Imf::TiledInputFile (like in exrinput.cpp), I don't think you hit that buffering.

Wait, I'm not quite sure how threads play into this. Is this allocated framebuffer part of the ImageInptut itself? Do threads lock to use it? Or is this per thread, per file?

I think the per-thread part is around ImfTiledInputFile.cpp::267. Each TileBuffer has an uncompressedData ptr which is what the compressor fills during decode.

This *should* just be a tile per thread, but it does look like it's held over the lifetime of the ImfTiledInputFile.