Some people can capture with AIW/VirtualDub/Huffyuv, WHY NOT

[psantucc]

Greetings All.

I have just spent another 100 or so hours in the attempt to capture decent video for the creation of SVCDs. All of my attempts fail, as has all of my troubleshooting. I am desperate, and hope that someone can suggest a new approach. I have only one caveat: I will only spend money on new hardware if it can be scientifically proven that a particular element of my current hardware - despite having compliant specs - is in fact faulty, and that a proposed replacement can be returned without cost to me if it does not suit my purpose. My time is my own to piss away; my money is not.

I have an ATI All-in-Wonder 128 32 AGP. I am capturing in real time using the Huffyuv codec. I have used both AVI_IO and Virtualdub for capture software, beacuse I am capturing segments too long for the 4GB barrier.

The problem is that at varing points within the capture, I drop frames in groups of 1-8. After I have encoded the result with TMPEGenc (fed through the Virtualdub frameserver) the points at which the frames were dropped display audio problems. Sometimes sync is lost; sometimes audio stutters. In either case, video hangs visibly for a second or so - substantially longer than the number of missing frames justifies.

The standard reasons for dropping frames - low CPU and low disk speed - have been elimiated by the statistics provided by Virtualdub and AVI_IO. I never show greater than 15% CPU useage or 10/50 buffers during capture, and all of my disks pass the Virtualdub test meter with plenty to spare.

My troubleshooting is complicated by the fact that I cannot watch the AVI files as captured in Huffyuv - my system cannot decode fast enough, so I can't see if there are any audio troubles until after I re-encode. To test for flaws in the TMPEGenc system, I have also tried compressing to DIVX with the same result - the encoder is not causing my problem.

Starting from the fact that there is always audible evidence of any problems, I decided to look to my audio card as the culprit. My card - an original Ensoniq Audio PCI - never had win98 drivers, so I've been using win95 drivers for the Creative Audio PCI 64, and they've been working, unless you count the record problem of current concern. To test, I completely removed the card and drivers from my system, and was able to capture the whole 30min test sequence without a dropped frame. Of course, there was no audio capture, so I couln't test sync.

So I borrowed a Monster Sound II from my friend and replaced the Audio PCI. It took me about 4 hours to install it (about which more later), but when I finally got it going, it's capture performance was the same as before.

The reason it took so long to install may have been a conflict in the IRQ settings assigned by my bios. When I added the sound card, the bios pushed my network card IRQ to 11, the same as my display card. I couldn't get Windows to start up except in safe mode. In order to make it work, I pulled the network card, permitting windows to start with sound and video. When I replaced the network card, it was once again assigned to IRQ 11, but this time Windows seemed to be working fine. I still have the same capture problem, though.

So I pulled out the network card and SCSI controller, and disabled my onboard parallel and serial ports, and restarted. There were no shared IRQs. No difference - about the same amount of dropped frames, and the same audio problems.

Some Harware summaries:
PII 500
System Disk: WDI 30 GB ATA 100
System controller: UDMA 33 on motherboard
Capture Disk: IBM DEskstar 60GB ATA 100
Capture Disk Controller: IWILL UDMA 66 RAID Controller
Video Cap Card: ATI All-In-Wonder 128 32MB AGP
Audio Card: Ensoniq AudioPCI OR Diamond Monster Sound II
AVI_IO Version C03.19
OS: MSWIN 98SE

Peak Performace for Capture disk from VirtualDub
Sustained Read 79257 K/s
Sustained Write 23903 K/s

Here's to hoping one of you can point me in a new direction. I'm about to give up and trash this box; I only bought the All-in-Wonder and Windows for video capture, and if I can't do that, I'm done.

Thanks,
Pat Santucci
psantucc@dnaco.net

[kinneera]

Under capture settings in VirtualDub, there is an option called "Lock audio to video". This option tells VirtualDub to drop audio packets as necessary to match frame drops (or something along those lines). If you don't already have it enabled, it might help with your problem.

Also, if the frame drops are coming in groups, you might check for background apps/daemons running in Windows that cause CPU usage spikes.

[Nelson37]

Had similar problems w/same video card, finally went around the problem this way - Capture Mpeg1 in ATI MMC 7.1, Bitrate 10-15, motion capture 99, I-frame only. Clip, crop, de-interlace & resize in Vdub, frameserve to tmpgenc.
I think the frame droppage is Drive related, when you get another Deskstar and stripe the two please post results as I am considering a similar upgrade.
The Lock Audio will mask it better but you still drop frames with AVI capture.

[asnamlar]

Hi, I had exactly the same problem and solved it using FreeVCR, a lot easier to use and worked perfect!

Good capture!

[ebaldino]

Hi Psantucc,

You just made me realize an added symptom of a problem I'm trying to solve: when I play a file captured with virtualdub and huffy, CPU usage jumps to 100% !! Hmm, gotta think about that... I have a PIII500 and AIW128...

The problem is, though, IT USED TO WORK, and I can't pinpoint what's changed...

So let me give you some feedback: the AIW is a very good card, once you get it working, which may take some time. You should be able to capture just fine with huffyuv with your system. Your bus speed is a bit slow but should take up to 480x480 uncompressed capture without dropping frames.

One tip is to go to VDub and under Capture/Settings set all buffer sizes to ZERO and then under Capture/DISKIO DISABLE Windows write buffering... that made the difference for me, but I was dropping frames out of my ears... since your statistics are OK, it may not make a difference...

On the other hand, dropping a few dozen frames over an hour's capture is OK, it's VirtualDubs normal way of keeping audio in synch, and you cannot notice it when playing back the files...

I presume you have tryed different source material...

good luck
E.Baldino

[ironwood321]

Have you installed ms office or and programming languages recently?

Check control panel and remove find fast. End task everything except explorer and systray. Delete mdm.exe from your machine.
Has your hard drive defragmented and contains no errors ?
Are you capturing to hard drive separate from your main one with no swap file on it.
Have you disabled screen saver and power saving settings?
right click on my computer and go to properties in performance there shouldbe a computer type option set it to network server. Disable write beind cache. Enable DMA on your hard disks? Make sure your hard disks are using dma in the bios not PIO?


<font size=-1>[ This Message was edited by: ironwood321 on 2001-09-17 09:40:03 ]</font>

[patrickm]

make sure to use drivers 4.12.6292 for the AIW under win98. you can also use this driver with MMC 7.1. what happens if you capture in a codec with just a slightly lower data rate? or does it only happen with huffyuv? in virtualdub, set the max audio buffers and put your video buffers at 100-200 or so.

[psantucc]

I'd like to thank all of you for your suggestions. I've tried most of them at one point or another.

I have at last got the video capture working to my satisfaction - dropped 2 frames over 1 hour capture, with no sync problems.

The significant steps seem to be:

Kill all running background tasks
Raise Video Buffers to 80
Set Disk I/O for 2MB chunks, 8 in buffer,disable windows buffering.

I might be able to beat those last two frames - I'd like to boost the audio buffers, but I don't know a good value for them.

Here's some things that did not work for me:
Lock Video to Audio - might be just for compatibility mode - can anyone confirm?
MMC7.1 - when I install it, I lose my AIW VFW drivers, and can't use VirtualDub at all.
FreeVcr- looks like a good proggy, but on my system halts about 4 minutes in with the following sequence of errors:
Error - Can't write into video stream
Error - Audio Data was lost during capture, reduce capture rate
Error - An error occured during capture

I have no idea what that is about.


I now have a new problem. The sequence of 4GB (well, 4000 KB, not real GB) files I generate loads as a group into VirtualDub, but I cannot scrub to the end of the last file - the scrollbar stops about 3 minutes from the last frame captured. If I load just the last segment, I can see all the way to the actual end. Any ideas what causes that?

Thanks again-

Pat

[ironwood321]

Hi,
Just out of curiosity. What are the Specs of your machine i.e. memory storage processor, capture set-up and what resolution video/audio are you capturing in?

The effect you experience with virtual dub not scrolling to the end of the file. I think is a bug I usually experience a similar thing when I use the append feature and add a 1 minute sequence to the beginning and end of my captures after I have converted them to my destination format.

<font size=-1>[ This Message was edited by: ironwood321 on 2001-09-18 06:56:21 ]</font>