What is HuffYUV???

[rchapoteau]

Ok I've been reading on and off in this newsgroup since back when the G200 came out, and I recently came back to reading it again. Apparently there is something called HuffYUV and I have no idea what it is. Can someone please explain it to me? Thank you.

[Hulk]

Huffyuv is a lossless video compression codec. Unlike MJPEG or MPEG, huffyuv's input and output are EXACTLY the same. You can think of it as saving each frame of video as a compressed TIFF image. It requires a relatively fast processor (usually 600MHz or faster) and a hard drive capable of sustaining 10MB/sec transfer rate. Most the newer high areal density drive are fine.

The beauty of huffyuv is that since the there is no lossy compression going on the final compression, be it MPEG or MJPEG does not have to work with a already compressed format. The result is very high quality output.

I'm just trying to help out so if I messed any of this up other members of the forum will surely correct me!

[Dr Mordrid]

You got it pretty much right Hulk.

Basically HuffYUV is the route to high quality video for many purposes. I use it to produce high quality MPEG's and streaming formats. By not having an intermediate lossy compression (MJPeg, DV...whatever) between the YUV source and the final format you gain a lot in image quality. Before HuffYUV came along what one had to do to achieve this quality was to capture straight YUY2 or RGB, edit and compress. Not easy.

The problem was that this required 21 mb/s for YUY2 and 27-30 mb/s for RGB of the drives (bare minimum & not counting overhead), so those without *fast* RAID arrays were just flat left out. Even with such hardware one was often limted to the outer tracks of the array because of the higher disk performance there.

What HuffYUV does is lower the data rate needed to do lossless captures to 10 mb/s or less, which allows most all quality 7,200 rpm ATA66 or higher drives to capture lossless video.

To use HuffYUV you do need a YUV video stream, or some variant thereof, as the source. To do this with a Marvel or RR-G you'll need to apply the Flying Dutchman's YUY2 patch to Matrox Video Tools ver. 1.52 to enable YUY2, the YUV variant that the Marvel uses. The Hauppage WinTV and some Pinnacle cards also provide this signal.

Once that's done you'll also need a capture program that can use it. PC-VCR cannot. Most of would recommend AVI_IO heavily since it does lots of other nice things besides capture YUY2. Here are the URL's you should check out;

DesktopVideoWorld D/L page (F.D.'s YUY2 patch): http://idiots-guide.matroxusers.com/DTVW_downloads.htm

HuffYUV 2.1.1: http://www.math.berkeley.edu/~benrg/huffyuv.html

AVI_IO: http://www.nct.ch/multimedia/avi_io/index.html

Dr. Mordrid


------------------
Asus P3B-F 6 PCI
PIII/850
Gigabyte GA-6R7+ slotkey
Matrox G400/Flex3D
Matrox RT-2000
256 megs RAM
Promise SuperTrak100 (4 x 60g IBM 75GXP: 240g RAID0)
AWE64 Gold


[This message has been edited by Dr Mordrid (edited 19 December 2000).]

[Monique]

Hello,Dr Mordrid
Could you tell me which Pinnacle cards can capture in YUY2 (in order to use huffyuv)
Thank you
regards

[dZeus]

while my name is not Dr. Mordrid, I can tell you that my Pinnacle Studio PCTV Pro (that's what they call the stereo version of the PCTV here in Europe) captures in YUY2 without any problem.... well... actually there is a problem, i.e. that it only captures in mono with virtualdub. It only captures stereo with the included app, which only allow capture in Pinnacle's propriety codec

[Monique]

Hello
Thank you for the answer
For my part I have a Marvel g400 and I make capture in YUY2 with AVI_IO and codec HUFFyuv without problem (DD 10000 t/mn celeron 466, ram 192)whith the best quality.
I fixed VCACHE as you said.
My purpose is making MPEG2 (SVCD) with Tsunami. By this way (in place of MJPEG) there is pratically no macroblocks, it's great !!!
But sometimes there is moise, so i would use VirtualDub in place of AVI_IO in order to use nice filters (unsharp, denoise, de-interlace)
if AVI_IO place keyflags for Marvel, it's no the case for VirtualDub. So the buffer are full and I drop a lot of frames.
Have you a solution because I red on this forum that someones use VirtualDub with Marvel and HUFFyuv.
Sorry for my english, but I am french speaking.
regards

[This message has been edited by Monique (edited 20 December 2000).]

[Monique]

Hello
Reading old posts, I understood that I have to come back to video tools 1.52
There is something else ?
Thanks

[Technoid]

Patience, crossed thumbs & ...

[Sciascia]

Monique,
Don't capture in V-Dub with filters on. I imagine that you would get a lot of dropped frames with that much processing going on during a capture. The filters are for post-processing as far as I know. I use avi_io to capture, then if I need to do some filtering, I use V-Dub to frameserve to TMPGEnc or whatever encoder with the filters. It is nice, because you can go through the clip and see the effect of the filters, throughout the entire clip, without capturing and then realizing that you made a mistake.

[bastioned]

Hello there. Just wanted to ask a dumb question: over two months ago, more or less, I read somewhere that YUV gives iu such a quality that iu don´t actually need to capture full res to achieve the quality iu get with MJPEG, in other words, that if I capture 320x240 or 352x288 in YUV->Huff I´d get better quality than 720x576 MJPEG. Am I correct? The purpose is for final DivX output, keep it in mind. OK smart guys out there , shed some light on me