Capturing in YUY2 at 640x480

[Doobie_Brother]

Has anyone done this with the Marvel G400? I have enabled YUY2 both by changing the ColorFormat registry key and with the Flying Dutchman's utility (separate tests). However, when I then try to set frame size either in AVI_IO or VirtualDub, 640x480 isn't an option. (I get the same choices as with dmb1).

I read one post (from Sun?) that talked about entering values directly into the DisplayWidth and DisplayHeight registry keys. I tried this and changed DisplayWidth from 704 to 640 but still no luck. Maybe I am doing something wrong? Can anyone help?

[Doobie_Brother]

I am trying to come up with the best settings for video capture/processing. At present, I use YUY2 and HuffyUV. This works well on my system even at 704x480. However, it creates very large files and I usually end up resizing at some point anyway. 640x480 would make a smaller file and might better suit my needs.

When I switch to RGB, there is a choice for 640x480 by default. I am just wondering how to get this with YUY2. Being able to set any horizontal/vertical resolution would also be very useful (SVCDs, etc). Does anyone capture at these non-standard resolutions with the Marvel and, if so, how?

I have tried VirtualDub's resizing abilities. Unfortunately, VirtualDub's capture mode makes my system very unstable. Strange, I have captured over 40,000 full-sized frames in one session with AVI_IO but I probably can't get 2,000 with VirtualDub. Also, for some reason, VirtualDub seems to place a much higher load on my CPU but, at max settings, AVI_IO utilizes only about 65%. I am curious whether other Marvel G400 owners do all/most of their capturing with VirtualDub. For post-processing, Vdub is clearly the best.

Anyway, thanks for the suggestion. I will try the new version of AVI_IO and keep my fingers crossed.

[Dr Mordrid]

Scaling YUY2 to 640x480 on the fly while capturing isn't really practical.

Capturing RGB at 640x480 is an option, but this too has a pitfall: you need about 28 mb/sec from your drive. This, of course, means a RAID array would have to be used. A Fasttrak66 with a pair of Maxtor DiamondMax Plus 40's would do it.

Dr. Mordrid

[Doobie_Brother]

Dr. Mordrid:

Have you been able to capture in YUY2 at resolutions other than the defaults? I know I read something about this but I can't seem to remember what it was.

Basically, I would just like to skip a step in the process --> capture with HuffyUV at 640x480, filter/process, and finish. I have noticed that to get acceptable output from DVDMax on a television set requires higher resolutions -- 352x240 and 320x240 don't cut it but 640x480 does.

[Sciascia]

Not trying tobe nosey, but why do you want to change the res. I belive that 704 by 480 is the correct res. If you really need 640*480, try the latest version of avi io, by Markus Zingg. It will allow you to select custom resolutions and it works great with the YUY hack and HuffYUY 2.1. There is a link to the site in "Links" on the left of this page. It has a free trial. Make sure that it is the latest version. It will be under the File>Capture settings. There is a box on the right hand side that says "custom" Check it and type in 640*480. then be sure to configure the settings under the video options and save them.

Good Luck

[Dr Mordrid]

I take back my comment that capturing to another format size with YUY2/HuffYUV isn't practical. I just did it. No registry keys necessary.

Filespecs:

640x480 YUY2/HuffYUV, 44.1khz stereo audio, total data rate: 8 mb/s

Set the Custom Format to 640x480 and use AVICap instead of the internal capture mechanism.

I found the setup "stuck" better if I selected the Custom Format last, just before starting the capture. Adding filters causes a few drops however.

System specs:

PIII/850, 256 megs, 120g Fasttrak100 RAID0.

Dr. Mordrid




[This message has been edited by Dr Mordrid (edited 06 August 2000).]

[intomisery]

8mb/s? are you sure? (well of course you are :P
I thought YUY2 needed 20MB + for captures.. something the avg. 7200 rpm HD couldn't keep up with.. at least mine can't.

what's the secret trick, doc?

[Dr Mordrid]

Using HuffYUV my man. It gives about ~2:1 compression. Combined with the narrower frame size (640 vs. 704) this takes the total data rate of the saved file down from 20 MB/s to 8 MB/s.

Dr. Mordrid

[intomisery]

ok, this is odd.
I'm using virtual dub
so I set the format to YUY2, choose custom size of 640x480
now, I set the compression (AVICAP) to huffy.
or should I set the internal compression to huffy and leave AVICAP at Full Frames (or perhaps No Recompression)

With this I get about 16MB/s still!
In addition, what is ment by filtering? what is this process and what does it accomplish?

thanks a helluva bunch

[This message has been edited by intomisery (edited 08 August 2000).]

[Dr Mordrid]

First off I'm using HuffYUV 2.1. Here's the sequence;

1. Start VirtualDUB (duh)

2. Set Capture File (E:\VDUB.avi, E:\ being my RAID0 array)

3. Settings (frame rate, etc.)

4. Set Audio Compression (I use 44.1khz, 16 bit)

5. Set Video Format (YUY2 @ 704x480)

6. Set Video Compression for AVICap (HuffYUV 2.1, YUY2/fastest)

7. Set Custom Format (640x480)

8. Capture w/AVICap

The total data rate runs from 7500-8300 MB/s depending on the content of the video.

Dr. Mordrid

[intomisery]

Yet again, this does not work for myself.
The first clue is VirtualDub says I'm using 1.0:1 compression and that the data rate is way about 8MB/s.

you're capturing 25fps, correct, that could be one difference.

In addition, this fast YUY2 does provide the best looking video.. the best settings will not give 8MB/s

My YUY2 also has problems capturing to 640x480. When reviewing the captured video, it is extrememly jumbled to the point of headaches.

ttys

[Dr Mordrid]

Nope, I'm capturing at 29.970 fps NTSC and my captures look very nice.

The MAIN problem I;m having with this is with VirtualDUB itself seemingly loosing track of what's going on.

While it capture/scales fine the first time subsequent attempts are not so reliable. I might get scaled captures or I might not. If not it saves 704x480. Seems to be a 60/40 deal respectively.

Dr. Mordrid