Hap, DXV and the like

voxish · March 15, 2013, 12:35am

Hi all,
Firstly, let me introduce myself, my name is Jim, long time MAX/MSP/Jitter user on Mac, based in Montreal. I’m looking into TD for better performance, reliability, and flexibility for interactive video installations.
I’ve just come across this new initiative by the guys at Vidvox, basically an open source, openGL based hardware accelerated video codec for OSX
vdmx.vidvox.net/blog/hap
Resolume has a similar codec available on Windows, but the hardware acceleration only works with their software.
resolume.com/software/dxv.php
I was wondering if there were any equivalents available for TD, or if was this was an area Derivative might be interested in exploring.
cheers,
Jim

malcolm · March 15, 2013, 12:43am

I am considering the hap file format. However, since DXV/Hap is just DXT compression, a sequence of .dds files will give you the same image quality and GPU decompression as these formats. .dds ofcourse doesn’t have the Snappy compression that Hap has, or whatever CPU compression DXV has (I don’t think they’ve published what they use).

voxish · March 15, 2013, 12:55am

Thanks, Malcolm!
I’ll look into this. Can anybody else suggest some un-Snappy DXT/dds workflows?
j

cedarconnor · March 15, 2013, 11:34pm

This sounded interesting so I rendered a 2048x2048 .dds frame sequence out of Maya. I also rendered the same sequence as .tiff .tga and .jpeg. I loaded these up in TD served from a single SSD.

Unfortunately I did not see a significant performance improvement. The info chop held at 25-28ms decode time.

2048x2048 animation codec QT plays back at 6-8ms decode time.

I’m interested in avoiding QT as much of my material comes from render farm frame sequences.

Any thoughts on how to improve this?

C-

marg8 · December 1, 2016, 9:01am

Sorry but I didn’t found correct information, does anyone know if TD supports movie DXV codec?

malcolm · December 1, 2016, 5:02pm

Hey,
I’ve actually also answered your Facebook posting about this too. I’ll paste it here for others to see:

Hap and DXV are almost identical codecs. Hap and Hap Alpha are both DXT1 and DXT5 texture compression, which is the same as the two base forms of DXV. Hap uses Snappy CPU compression while DXV uses lzf, both are very comparable in speed/size. I’m not 100% sure if DXV even has an equivalent to Hap Q. The FFmpeg source mentions two unimplemented codecs tags (YCG6, YG10), which may be Hap Q equivalents. I’d be surprised if you got worse performance using Hap in TD than you got using DXV in Resolume. A big question is how each app implements their decoder. If you are comparing DXV vs. Hap in Resolume and finding a large difference, I assume it’s because Resolume has made a more efficient decoder for DXV than Hap. In TD our Hap decomrpessor is going to be the fast path as that’s what I’ve spent my time making fast. So, it’s not about DXV vs. Hap, its about using the codec which the app has been optimized for.

No we don’t currently support DXV in 088. I’ve spent a lot of time making our Hap playback ultra-fast, as well as extending the Hap specification to add more features, such as Hap Q Alpha and chunked encoding. I can do this because Hap is an open standard while DXV is closed.

So even if we did support DXV, the Hap performance would be superior by a long-shot in TD.