Calling all YUY2 experts...

[ffynnon]

Hey all!

<just finished writing and realized I should get to the point. Here's my questions in point form, followed by the background info...>

1. Is anyone capturing YUY2 CIF 352x240 and encoding into MPEG-4 successfully with virtualdub 1.3a? Meaning audio maintains sync with video for duration of clip.
If so, how. What are your specs?

2. Why on earth is my capture not syncronizing?!

3. What is wrong with WDM drivers, and how can I get drivers without WDM for my SB live? (from Microsoft's site, is seems WDM is the protocol used for any 32-bit audio workings.

I'm attempting to sqeeze as much quality out of my G200 Marvel as possible, and seem to be hitting my systems limits (specs are at the bottom). I'm curious how many people have similar setups, and just what kind of specs you need to actually pull it off.

YUY2 that is. Let me just state (as I'm sure many of you know), that Virtualdub is one kickass piece of software. However, no matter what type of YUY2 capture I try, no matter what compression setting, my audio is WAAY out of sync. It stays in sync for about four seconds and then starts to wander. (video falls behind). All this without dropping a frame! Bizarre if you ask me.

I have the dreaded (i'm learning) SBlive value. I got it to take it's own interupt, and installed '95 drivers for it as suggested by very vague references in this forum to WDM drivers being no good. ??? Am I missing something?

In any case, I'm a quality freak, and MJPEG just doesn't cut it. I'd love to work in uncompressed, but my HD just won't allow it. I thought virtualdub's realtime MPEG-4 compression would be great, but it just won't sync up. I've tried "sync to video" both on and off. I've messed with the buffer sizes with no apparent difference. Is it my sound card? Slow processor? Lack 'o RAM? Is anyone doing this while maintaining sync? HOW?! What are your specs?

Here's mine:

PII-400
64 meg PC100 RAM
G200 Marvel
SB Live Value
WD 18 gig 7200 rpm
Win 98 (not SE)

SB is irq 10
Marvel is irq 11

[Driver]

if virtualdub shows that your system is reaching about 100% use of its resources, then this is probably why because it is having a hard time keeping up. what format are you storing the audio in. it may be helpful to decrease the bitrate of the audio capture and see how much this affects synchronization since a high bitrate, uncompressed audio stream can take up a lot resources in terms of space on the hard drive . Also, if you are not already, try decreasing the video capture size to about a quarter. I've found that my system, which is similiar to yours, can do a good job that way.
Good luck

[RBryant]

First of all, don't believe the hype.

I've used several programs to capture in everything from raw RGB to YUY2 to MJPEG. These include VirtualDub, MSP6, Premiere, and AVI_IO among others. By far and away the best one is AVI_IO. It is the only program that maintains audio sync over long captures, or atleast in my experience. It does this by intentionally dropping a frame every 1000 or so to allow the video to catch up to the audio. I've capture 160 min long clips with perfect sync thanks to AVI_IO ( Markus, you rule!). Not only is this dropped frame undetectable, it is actually meant to be there, hence the 29.97 fps of NTSC instead of 30.00 fps!!

And you know what? I've been doing it for months with an SBLive!. People that complain about WDM drivers just haven't quite got all of their hardware working together correctly yet. Every slot on my Tyan motherboard is full, and everything works great....

I have captured 352x240 YUY2 -> MPEG4 before with no problem on my 500Mhz machine. I can't do 352x480 YUY2 -> MPEG4 although I can capture 352x480 YUY2 without the realtime MPEG4 encoding just fine.

So, the moral of the story is, get AVI_IO and switch back to Live!ware 3.0 it works great for me.

Garrett

[ffynnon]

Thanks everyone for the suggestions/replies! I was trying to capture audio PCM @ 44.1 stereo. Indeed my resource usage was 100% quite consistently. I did some digging though, and discovered DMA on my HD had been disabled! Geez! Enabling it again (anybody's guess how it was disabled...) dropped my CPU usage down to the mid 60-70's. Now it works! I haven't captured anything beyond 5 min. in length, but sync is bang on so far!

I think I'm going to reinstall Liveware and see what it does. Nobody has further info on WDM drivers though?... I know nothing beyond some people don't like them. Why?

thanks!

[Michel Carleer]

I am also capturing in YUY2/MPEG4 without a sync problem. With a SBLive! and LiveWare WDM drivers. But only under win98. win2000 gives me ~10% dropped frames, no matter which format I use, with or without compression, with or without sound. All this with VirtualDub or MSP6 capture. AVI_IO unfortunately crashes under win2000, on my PC.
Michka