Hi,

I just discovered how wonderful the "my ViVo" function of my gfx card can be and I'm now going to digitize some VHS videos of mine.

I have a Leadtek A310 TD my ViVo (I dunno what analogue video chip is used =/) and it seems that I can only encode with in UYVY and using the Huffyuv 2.1.1 codec gives me a compression ratio of 1.8:1 at Full PAL (720x576).

From the Huffyuv homepage's benchmarks I saw that much higher compression can be achieved with this codec, but somehow I have to set my Video card to capturing in YUV2 which it doesn't seem to support.

So I'm asking now how to get my card to capture in YUV2, or howto recode from UYVY to YUV2 on the fly during capturing and then compress the raw YUV2 stream with Huffyuv. Or is there any other lossless codec doing all that in a much better way than Huffyuv does?

Anyway I'm quite new to video, so I might have gotten some things wrong, especielly with Huffyuv compressing UYVY and not transcodingt to YUV2. Maybe it does use YUV2 internally and a compression ratio of 1.8:1 is just normal.

If that's the case then I should capture in mpeg2 directly. =( It's impossible to capture a 2h movie if you only got 15gig free disk space with a ratio of 1.8:1!

Maybe you should try mjpeg for capturing. Mpeg isn't ideal if you want to transcode the video later to burned or something. Using mjpeg you can achieve 14:1 or something with good quality(Picvideo mjpeg @ quality 18 if I remember correctly).

1. mjpeg isn't lossless. (mpeg2 isn't either but that was only as a last anchor)

2. mjpeg adds some text to the video if using the unregistered version

I also like to compress the captured material with DivX or xvid and I came across a site or a post somewhere that said using a codec that was intended for viewing and thus throws away a lot of the information from the video for capturing gives bad results after compressing the captured avi again. like transcoding audio from ogg to mp3 for example, even if I'd use quality 19.

Bad news for me:

From a TV tuner project site for the linux platform: "Starting with version 0.8.3, RivaTV no longer supports colour formats other than those supported by the nVidia hardware. This means only the UYVY is supported."

This means I need to find a lossless codec that supports UYVY on-the-fly compression with high compression ratios. Or one that will convert UYVY to YUV2 (still I'm confused: is YUV2 better for lossless compression than UYVY?) before compressing the video.

I didn't claim it to be lossless but mjpeg's quality is good enough for transcoding to some other format for archiving. I recommended mjpeg because it has pretty good space/quality ratio.
YUV2 might have less colour information stored and therefore it might compress better. If YUV2 has less colour information than UYVY, the conversion from UYVY to YUV2 is lossy.

I find VBLE works reasonably well. It is a YV12 version of huffyuv I think, but it is fast and compresses better than the regular huffyuv because it works in YV12. However, it can be a little hard to find, so I put up a version here http://www.geocities.com/bonzi5252 there are a number of lossless codecs though which do compress better there is marcfd's latest lossless creation MILK and CorePNG (which is tremendously slow but compresses well) as well as ffv1 which is a lossless codec from ffmpeg. It compresses very well but you may have problems capturing in realtime on a slower computer mine is p4 1.8ghz and I get approximately 18-20fps at 720x480 which isn't good enough. MILK can be found here http://forum.doom9.org/showthread.php?s=&t...&threadid=65008 and CorePNG here http://forum.doom9.org/showthread.php?s=&t...&threadid=64139 and ffvfw can be found here http://athos.leffe.dnsalias.com/ Probably, the codecs that will work the best are MILK and VBLE the others might be too slow especially CorePNG. For a guide on TV capture take a look at this http://www.doom9.org/capture/start.html

Ok thanks for those suggestions, Bonzi.

I have now come across a lot of lossless codecs and I think I will just start to test a few. And I will give VirtualVCR a try, too. It's a 100% WDM app, unlike VirtualDub, which uses a VfW->WDM wrapper. Reading the Doom9 Forum a bit, I read that using a full WDM capable app to capture @ full PAL is a must under 2k/XP, I guess due to performance and compatibility reasons. Actually when I choose an colorspace for capturing that was unsupported by my nVidia card like YUV2 , the whole VirtualDub program was acting very slow and gave a exception error.

fandango;
1-you haven't tried mjpeg,so i say you should (leave the prejudice and other folks' thoughts behind you....nothing beats mjpeg's quality/bitrate ratio...)
2-colorspaces?worry not;UYVY is same as YUY2 but byte ordering is different...(ie. there's no real difference)
http://www.fourcc.org/yuv.php
from
http://www.fourcc.org/
you card has philips capture chip,and therefore you use UYVY...
codec tthat works in YUY2 will work in UYVY too..(u saw huff does....mjpeg does too...)

i would stay away from YV12 lossless capturing;probably only god knows what those codecs are doing to interlaced content....(ie. how they treat chroma)
it's bad enough final video (mpeg) will be YV12....i say....
i wouldn't bother witth YV12;it was never ment to be used for capturing....

@bonzi;show us how does your saturated red color looks in vble or whatever yv12 codec....



huh,i'm glad i leaved that forum sooner rather than later if they're writing such crap.....(although i helped to improve one version of that guide.....see appendix and "thanks a lot" for 2nd release...)
in short;because all of the "benefits" of the wdm system,i'm using win98 and vfw+vdub for capturing....
i can capture via vdub on w2k too (at 768x576) ,but the sync drifts away...
but wdm has those sync issue with wdm app's too....(in my experience...)
(so that's NOT a must nor is it a solution for every case...but sure,on wdm one should first try wdm app's)

i hope you won't get those sync issues....
on same subject one thing is worth noting;developer of virtualvcr recently bought mpeg2 hardware capturing board......seems like he gave up wdm capturing too...
http://www.digtv.ws/html/review/pctv-deluxe.html

also,see this
http://virtualvcr.sourceforge.net/forum/in...6&hl=audio+sync
for info on how good particular cards work with vvcr....

you may wanna do a search for "audio sync" on that forum too...


good luck

/ivo

huffyuv>mjpeg, simple as that. Lossless until final encode. With mjpeg you get artifacts upon artifacts since every single frame is a jpeg. Which in the end means worse quality, obviously. Yeah, maybe your eye will accept jpeg after jpeg, but you have to remember you're not feeding it to your eye. You're feeding it into a video encoder, which will be able to do a better job (i.e. better quality per bitrate) if you aren't feeding it 'dirty' data. Keep it 'clean' until you're ready to encode to its final destination, so that only that final codec changes anything. The final codec will be doing it's own jpeg-type stuff anyways so you shouldn't be doing that multiple times, making it worse each step of the way. Unless it's some job where you don't give a rat's ass about the quality.

might change your mind about YV12, have a poke around here, most particularly check out the seperated/recombined images of the chick on the hood of a car.
http://nfg.2y.net/games/ntsc/

where?
post exact link and not a link to article that says "screw you" to pal users...

i told you,post a image where bright red looks OK in YV12 and i'll be surprised.....
(not a one-color screen,but natural image with red in it...)
ah wait a minute....
it's on
http://nfg.2y.net/games/ntsc/visual.shtm

this chick is on WHITE car,so where's your "YV12-loving reds" test?
this page tells NOTHING about YV12....

if you were into capturing you would spot the differences between YUY2 and YV12 by now...and would never use YV12 as a capturing codec....

if you still don't believe me,i'll make a web page to show you what i mean.....

instead of skimming, how about you actually read the whole article? The fact that you're pissed about the PAL comment shows you didn't read. You're all mad over something said in jest because the whole point of the article was to discuss NTSC and completely ignore PAL because PAL handles things better as far as the issues discussed, duh. The fact that you think YV12 is horribly broken also shows you didn't read. The fact you think that article doesn't have anything to do with YV12 proves undeniably you didn't read. Sure, perhaps it's better to stick with YUV2 during the capture process. But in the end you're going YV12 anyways if you're going to DVD, no? At the very least, retail DVDs are YV12. You may find the chroma decoding bug mentioned there interesting.

You have sync issues capturing with virtualdub? I'd say something's wrong with your box, be it software or hardware, something.

that's all that i'm saying my friend...that's it!
i know end codecs are YV12 and i know they hate saturated reds....you may of seen it too...i know about CUE also...it is a decoding bug and it's quite interesting to see how many dvd players have it...

i'm not pissed about PAL..dosn't matter at all....
i didn't read it?
sure,because it was YOU who provided the link to exact page you were talking about....for sure...the girl on a car...


i have issue on WDM(as MANY other people) and NOT on VFW...now take a wild guess with what system am i capturing.....shouldn't be too hard....WDM drifts off-sync,remember....VFW doesn't....
also i haven't asked you to help me with my WDM issues....you won't be the one solving them anyhow...nor will i..it's up to the microsoft (ie. it won't be solved...heheh)..so i have dual-boot machine...problem SOLVED....

i have come here to say that YV12 is a lousy way to capture...

i still say use YUY2 for capturing,it's bad enough YV12 is the end format....god knows how will codec react when it sees YV12 as a source and what will it do to the color...

i won't change my mind on capturing...if you're capturing too,you should try both formats and see which one's better....