Merci Francois
Thanks Nathan

Will definitely have a look at this 

On Fri, Nov 20, 2015, at 10:49, Francois Lord wrote:
> Salut Hugo.
> 
> For playback, the B44 and B44A are much better suited. They are lossy, 
> but for most playback uses it will be negligible. Any other compression 
> method will be very taxing on the cpu for 4k content.
> B44 and B44A, of course, are only a valid option if you want to export 
> your images just for playback.
> 
> Also, it pays to tweak the formats preferences in RV. We've had big 
> performance improvements from exr and dpx by playing with these 
> settings. The RV user manual gives some hints as to where to start.
> 
> www.openexr.com/TechnicalIntroduction.pdf
> 
> B44 (lossy)
> Channels of type HALF are split into blocks of four by four pixels or 32 
> bytes. Each block is then packed into 14 bytes, reducing the data to 44 
> percent of their uncompressed size. When B44 compression is applied to 
> RGB images in combination with luminance/chroma encoding (see below), 
> the size of the compressed pixels is about 22 percent of the size of the 
> original RGB data. Channels of type UINT or FLOAT are not compressed.
> Decoding is fast enough to allow real-time playback of B44-compressed 
> OpenEXR image sequences on commodity hardware.
> The size of a B44-compressed file depends on the number of pixels in the 
> image, but not on the data in the pixels. All images with the same 
> resolution and the same set of channels have the same size. This can be 
> advantageous for systems that support real-time playback of image 
> sequences; the predictable file size makes it easier to allocate space 
> on storage media efficiently.
> B44 compression is only supported for flat images.
> 
> B44A (lossy)
> Like B44, except for blocks of four by four pixels where all pixels have 
> the same value, which are packed into 3 instead of 14 bytes. For images 
> with large uniform areas, B44A produces smaller files than B44
> compression.
> B44A compression is only supported for flat images.
> 
> 
> Cheers!
> 
> F
> 
> On 2015-11-18 20:29, Hugo Léveillé wrote:
> > Hey guys
> >
> > Anyone of you ever tested 4k 16 bits exr in zip1 in RV for realtime 
> > playback? We have a 1.4 gigabytes raid so the bandwidth is not the problem 
> > as we need something like 900MB.
> >
> > But the CPU is dying when decompressing the frames. Before trying something 
> > else, anyone successfully played this in realtime in RV?
> >
> > DPX is playing fine be we are trying to make a exr only workflow.
> >
> > Thanks
> >
> > Sent from my iPhone_______________________________________________
> > Nuke-users mailing list
> > [email protected], http://forums.thefoundry.co.uk/
> > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
> >
> _______________________________________________
> Nuke-users mailing list
> [email protected], http://forums.thefoundry.co.uk/
> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
_______________________________________________
Nuke-users mailing list
[email protected], http://forums.thefoundry.co.uk/
http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users

Reply via email to