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**Flying dutchman** · 31 May 2001, 22:49

More likely the sound card. Does it drop any frames if you record video without audio?

It may help if you disable the "midi" part of the sound card, it is known to generate a high PCI load on a SB Live...

**Debbie** · 31 May 2001, 23:30

Hi Flying dutchman,

Thanks for the advice. My sound card is a Creative AWE 64.

At the moment I can't try what you sugested,
but I shall give it a try this afternoon.

The system in my laboratory consists of 1 drive ATA 66, Windows 98 and Creative PC1 128
sound card and I have no problems.

By the way, a big thanks for supplying the video capture comunity with the YUY2 Patch.

It's nice to keep in touch with Dutch.

Best regards,

Debbie

**Nethermancer** · 1 June 2001, 00:50

I've been wanting to disable MIDI on my SBLive for ages but can't find the option. How do I do this? Thanks.

**Flying dutchman** · 1 June 2001, 05:57

Hi Deb,

I can only tell you from my own experience that I never got it to work properly with a Soundblaster 64-PCI or a Soundblaster 128-PCI in a Gigabyte BXE board (celeron 466) without dropping frames. With a soundblaster 16-ISA it all worked perfectly - not a single dropped frame!
Last week I bought a new motherboard (Gigabyte GA-6VX7-4x) with a VIA chipset and an on-board soundchip. Guess what? Despite what everybody says about VIA chips, it worked fine first time, so I could finally ditch the ISA cards. Now that I've practically re-built the whole PC around my Marvel G-200, I'm all set to move to Windows 2000. You can imagine that I'm more than a little furious about the win2000 driver issue. If they really drop YUY2 support for the G200, I solemly vow never to buy another Matrox product again. I invested at least $1000 in upgrades to get it all running the way I want (two motherboards, two cpu's, three sound cards, two hard disks, Avi_IO...) !!!

Now for your problem: Try the following things.

1- It is necessary to use a dedicated hard disk for capturing. This disk should run in UDMA mode. Keep it defragged !!!

2- In your Bios setup, make sure "clock spread spectrum" is disabled. It makes the clock frequency of the PC wobble a bit in order to spread out RF peaks. This deliberate inaccuracy is certain to cause dropped frames.

3- Disable the MIDI part of your sound card - it generates a high PCI bus load!

4-Isolate the soundblaster and Marvel on separate IRQ's.

5- Experiment a bit with the "Pci latency" value in the bios.

If you are still dropping frames, you really need to get a different sound card. ISA cards such as the SB16 work fine!

**Flying dutchman** · 1 June 2001, 06:02

Nethermancer, that depends very much on your soundcard drivers and if you use Win98 or -2000.

Either: Open Control panel\Multimedia,
edit the tabsheet "devices" and disable all midi stuff.

Or: Open control panel\System, tabsheet "device manager" and disable the midi driver of the sound card (if listed separately)

**Debbie** · 1 June 2001, 06:44

Hi again Flying dutchman,

Thanks for your advice, will try as soon as I get home.

So it's not a matter of having 2 hard disks with different specs.

Data saving HD = IBM, 20 GB, ATA 66, 5400
Software + OS HD = Fujitsu, 9.4 GB ATA 33, ???

Have a nice weekend. Best regards from Malta,

Debbie

**Debbie** · 1 June 2001, 06:58

Flying dutchman
PS.

I too am digusted with the Matrox treatment.

This is my second Matrox capture card I still have the Rainbow Runner Studio that I still have.

Also,have upgraded my machine with new MB,HD and more SDRAM, But now I'm stuck with Win 98 SE thanks to Matrox. Sob,Sob,Sob

**Flying dutchman** · 2 June 2001, 09:21

Hi Deb,

UDMA is easily fast enough (use it myself). Capturing using YUY2/Picvideo or Huffyuv puts a tremendous PCI load on the bus because the raw video data gets transferred to memory before re-compression with a software codec. MJPEG has a huge advantage there. If I capture YUY2/picvideo, the sound is somewhat distorted as if audio samples are missing. I re-inserted the SB16 and all was fine again... For the time being, I prefer to capture in MJPEG and tweak the data rate up a bit. I can't use the SB16 because I need the single ISA slot for a streamer card...

**Debbie** · 2 June 2001, 21:09

Hi Flying dutchman,

I have pluged in a PCI 128 Sound blaster card but it's no use. I have fixed the frame drop problem, it was amatter of activating DMA, I forgot it off, but the sound is still not to the mark.

I have reduced capturing to the lowest levels but nothing doing. The sound problem is arising when I use software compression in real time capture eg. PicVideo or the LSX MPEG encoder.

Has the SDRAM speed got anything to do with this problem ?

Regards,

Debbie

**Flying dutchman** · 2 June 2001, 22:29

Hi Debbie,

it still sounds like a SB-PCI issue. My sound is distorted too if I use a PCI (or even onboard) sound card, like if samples are missing (dropouts). Especially noticeable in the loud parts.
As I said, capturing YUY2 and using a software compressor puts a terrible strain on the PCI/AGP bus (22 mb/sec of raw video flowing from Marvel to PC memory; 3-10 mb/sec of compressed video from PC memory to hard disk).
An ISA sound card performs MUCH better than a PCI card in my case - no dropouts. Check your BIOS for an item called "PCI concurrency" and see if tweaking it helps...
By the way, what motherboard do you use?

**Debbie** · 3 June 2001, 21:02

Hi Flying dutchman,

I spent all Sunday playing about with the sound, trying what came across my mind but not a chance.

I changed the sound card and RAM with he ones
I have in my lab. but again nothing doing.

I am using a Tyan MB with Apollo Pro Via Chipset 133A. All the specs. are here:

http://www.tyan.com/products/html/trinity400_p.html

The MB I have at the lab. is a Soltek also with Via 133 cipset but the version is different, VT82C693A.

Regards and thanks for all your help,

Debbie

**Flying dutchman** · 4 June 2001, 01:48

Hi Debbie, your motherboard's hardware is more or less identical to mine. Yours has a newer "Southbridge" (686B), which is the one that is suffering from the UDMA bug on the second IDE channel (which has nothing to do with your problem BTW).

Is your sound choppy also if cou capture plain vanilla Matrox MJPG? MJPG doesn't put such a huge strain on the PCI bus (3 mb/s). If this reduces your audio problems, you can bet your life that the PCI load is the culprit. Pleast, try to borrow an ISA soundblaster from someone; I'm pretty sure it'll solve your problem (and they only cost $20 or so...).

I'm gonna be away for a week now - see you all then...

**Debbie** · 4 June 2001, 03:23

Hi Flying dutchman,

My original sound card is the Creatve (ISA) AWE64.

Matrox MJPEG capture is fine both picture and sound.

I shall try another ISA card now.

Regards,

Debbie

**Flying dutchman** · 9 June 2001, 16:05

Hi Debbie,

The synchronicity issue with the new ESS 1868 soundcard you mention in your e-mail is because of the inaccurate quartz on the sound card (if it has a quartz at all!) . I used to have one of those cheapo ESS1868 sound cards too, and it had no on-board quartz crystal at all! So it either used an (inaccurate) R/C oscillator or some other black magic to obtain a 44100 Hz clock frequency. In short, it sucked - sound and video weren't synchronous at all.

Yet since this ISA card solved your audio dropouts problem, I guess you're on the right track... I saw your posting about the SB16, did you manage to get one of those? Windows 98 has pretty good drivers built-in. Just disable the "legacy" support which is normally at IRQ 5, address 220h...

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