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**Grigory** · 26 September 1999, 23:28

Rick,

I am not sure about FastTrack, but I had similar experience with single UDMA drive.

You have to enable DMA under NT. There is a utility Dmachk, but it may not be able to enable DMA by itself. To be sure, you may need to edit the registry to force DMA.
Until I did this, Nt captures were with dropped frames.

You can search for information at
URL=http://www.bmdrivers.com/ntdma.htm

Hope this may help

Grigory

**Rick6612** · 27 September 1999, 14:07

Hi Grigory,

Thanks for the info. The Fast Trak shows up as having DMA enabled, but my boot drive does not. Since I am only capturing to the Fast Trak, I am assuming this should be ok...?

I tried using the DMACHECK utility to enable DMA for my boot drive. It now says that DMA Detection is enabled, but that DMA is not in use for the boot drive.

I also tried adding a DMA Detection Level entry to the Registry, following directions I found on another web site. This did not work for me either. However, this method did get DMA to work on a friend's PC, so I don't know why it won't work on mine.

When I boot up under Windows 98, of course everything is fine as far as DMA goes.

Rick

**Rick6612** · 27 September 1999, 14:08

Hi Grigory,

Thanks for the info. The Fast Trak shows up as having DMA enabled, but my boot drive does not. Since I am only capturing to the Fast Trak, I am assuming this should be ok...?

I tried using the DMACHECK utility to enable DMA for my boot drive. It now says that DMA Detection is enabled, but that DMA is not in use for the boot drive.

I also tried adding a DMA Detection Level entry to the Registry, following directions I found on another web site. This did not work for me either. However, this method did get DMA to work on a friend's PC, so I don't know why it won't work on mine.

When I boot up under Windows 98, of course everything is fine as far as DMA goes.

Rick

**DrMordrid** · 27 September 1999, 17:42

In my dualboot system (Win98 original, NT4-SP5) I also use a FAT32 filesystem to access my Fasttrak RAID, but I use Winternals product. It's excellent. I've had no problems at all. The RAID benches even faster under NT4 than in Win98 or Win95-OSR/2. The longest capture on it so far is over 150,000 fames using AVI_IO full.

Dr. Mordrid

**Rick6612** · 27 September 1999, 19:56

Hi Doc,

As far as I can tell, Sysinternals and Winternals are pretty much the same thing, no? I mean if you go to the Sysinternals web site, it says "Sponsored by Winternals." And when you click on the link to buy the full version of FAT32 for NT driver, it takes you to the Winternals web page.

Anyway, what is the secret to getting this stuff to work under NT?

What do you use to benchmark under NT? I tried to install Sisoft Sandra under NT and I got a warning message that said it was NOT designed for NT and it asked me if I really was sure I wanted to install it. Since I now have an 18GB boot drive, I can no longer just reinstall NT if it gets screwed up without wiping everything out (Win98, etc.). So now I am very reluctant to do anything at all that might mess it up.

I was pretty happy that I managed to capture 10 minutes with only 2 dropped frames using AVI_IO under NT. But then I got to that one scene that just wouldn't capture under NT without droping 80 frames.

MSP Video Editor seems to work OK under NT. I'm not having any trouble with that.

Playing back video under NT is still a problem for me, though. I frequently get jerks or stutters during playback.

Of course, as I've said many times, everything works perfectly when I boot the machine with Windows 98. The 25 minute video of my daughter's birthday party captured with 0 dropped frames using AVI_IO under 98. I edited the entire thing with MSP only crashing once. Playback to video tape was perfectly smooth...

Rick

[This message has been edited by Rick6612 (edited 09-28-1999).]

**Grigory** · 28 September 1999, 00:42

Rick,

History of Fat32 driver for NT:
Winternals site was original one, where we could find Fat32 access drivers for NT several years ago. Later, the company decided to move commercial product to another site, called Sysinternals, because they also made several utilities for non-windows systems.
Full Fat32 drivers from Winternals and Sysinternals are binary equal. I am using these drivers for 3 years without a problem. The only one trouble I got is when I tried to install Fat32 driver on fresh NT installation on a system that had no NTFS drives (FAT16 & 32). The system was working at 1% speed. Every dialog was opened in one minute! The solution was to manually enable and set NTFS service to start on system boot. Fat32 driver probably uses NTFS service in operation. However, after this trick, I am using NT with fat32 since february and used it for beta-testing of NT RR_G drivers in a short period when I was Matrox beta-tester.

Now about dropped frames.

It may happen that you use different input/output br/con combinations under 98 and NT. It is possible that even equal settings give slightly different actual levels under different systems. It is also possible that NT driver has lower frames size limit.

Your ability to capture 10 minutes of video makes me thinking that the drive itself is not a problem. I remember that I could not capture with DMA OFF at all.

Are you using Hi-8 or better source video?
If yes, are the input brightness and contrast settings under NT and 98 equivalent? If yes, can you check that equal numbers in these settings are producing actually equal MJPEG files in terms of brightness and contrast?

If you remember my old collisions with Matrox, one of my points was that RR_G might sometimes be unable to capture very crisp and bright video without dropping frames.

The final explanation from Haig was:
Sometimes, Zoran chip can produce the frame that is too big in size. If the size of a frame becomes bigger than certain value, Matrox driver had to drop the frame because this frame will cause bad problem later on recording or playback. The critical frame size corresponds to a limit is ~4MB/sec instantaneous data rate, which is possible to get for some video fragments.

The frame size for a given video source depends on brightness and contrast settings. Higher contrast or brightness more likely can give you a trouble because of bigger frame size.
In my case, I could not make playable video for one particular scene untill I reduced the input contrast to a level below acceptable value. I had only playback problems, but they occur on certain frames that had unusually big size.
For the same movie, any attempt to increase the conrast over my normal value resulted in mass frame drops.

Two solutions are possile, if the problem is with input video/ zoran chip incompatibility.

1. Reduce the input brightness and constrast slightly, down to the level which you still can accept or correct later. See if this helps to reduce the number of dropped frames.
2. Edit the registry and set the video quality to be 10% lower than what you use for original captures. This will force zoran chip to make smaller frames that can fit the driver limit. I used this trick successfully.

Finally, I can say that 100% safe capture compression level is below the maximum allowed by Matrox, somewhere in between 6.6 and 8. With 6.6 value you can get >4 MB/sec instant data rate which may be impossible to play, or get a lot of dropped frames with some video content.

Grigory

**Rick6612** · 28 September 1999, 14:57

Hi Grigory,

Thanks for your response.

I never did anything with the brightness or contrast levels under NT, and I do remember adjusting them under 98 quite awhile back, so you are probably right that they are not equal.

DMA is ON for my Promise Fast Trak RAID, which is what I am capturing to. I still can't get DMA ON for my boot drive, though.

I am using a consumer level Sony Hi-8, 1 CCD camcorder as a source. The particular video I was capturing was of my daughter's birthday party, all shot indoors in a pretty evenly lit room. Where the frames started dropping was in the middle of a scene where all the girls were gathered around a table to open presents. There were no drastic changes in anything in the scene when it suddenly started dropping frames.

I guess I will have to try to play around with it some more and see if I can figure out where the problem is.

Rick

**Rick6612** · 29 September 1999, 12:25

Hi Grigory,

I tried to play around with the brightness/contrast/etc. settings under NT and I found that it's not the same under NT as under 98. I couldn't find either the input or output settings in the usual places when running under NT. Do you know where they moved these settings to?

Rick

**Grigory** · 30 September 1999, 01:57

Rick,

I am sorry to abandon RR_G forever since I moved to DV Raptor. Because of this move, and GREEN TINGE of my Mystique card, I did not dig to adjust video in/out settings for a while.

Your problem seemed to be similar to what I got before May. That is why I replied.

Also, I had enough time to realize that so-called drive performance problems are not so serious as many of us think. Well designed PCI card and modern IDE drive can easily record 3.5 MB/sec even under NT, and even in two streams, as in the case of my BT848 card and Raptor - I was able to capture DV and analog video from D8 camcorder simultaneously on two separate IDE drives with 3.6 and 7.0 MB/sec datarate. So, the drive performance is now only the last reason for dropped frames.
I use only cheap UDMA33 drives from Fujitsu, which never were reported as performance leaders, but work flawlessly both in DV and in uncompressed video captures of 10-12 MB/sec.

Grigory

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Dropping Frames Like Crazy When Capturing Under NT

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