More frames dropped than captured

[LAJ_26]

Hello,

Transferring DV data from my camcorder to my PC used to work flawlessly months ago, but then it suddenly went horribly wrong and I've never been able to fix it. The PC works fine but transferring DV is a no go- after 3 seconds of capture using DVIO, captured frames were 36 and dropped frames were 38, and as capture goes on this gap widens to hundreds of dropped frames within a few seconds. The result is unwatchable video that looks like it's being fast forwarded. I retrieve the same results with WinDV and Movie Maker. Playback of old DV AVIs that I captured with my previous PC is fine.

I followed the FAQ articles. My HDD is running in Ultra DMA Mode 5. I bought a new firewire cable just to rule that out. It's a Dell PC with a 3GHz Pentium 4 and 512MB RAM which I assume is powerful enough as the 1.4GHz Athlon with 256MB RAM PC that it replaced could handle DV transfers fine and my 4 year old laptop can handle it all with minimal dropped frames. This is the main family PC so I ideally want to get it working on this.

I'm not sure what other information to give but I seek guidance as to how I can further diagnose the problem as it's been on my todo list for months.

Thanks if so.

[edDV]

It should work on that machine. Is the disk full or some app is pushing the CPU to near 100%?

It should work easily even on a 500MHz PIII.

[LAJ_26]

No the HDD has loads of space left and CPU usage is at 0-2%. I've tried capturing after closing my virus scanner and other background services but with the same results :/ Are there any free HDD diagnostic tools which can test the read and write rate?

[JohnnyMalaria]

I'm not sure what other information to give but I seek guidance as to how I can further diagnose the problem as it's been on my todo list for months.

Would you mind trying our Enosoft DV Processor? It uses the same underlying framework as WinDV, Movie Maker etc to capture. One of our testers has reported lots of dropped frames when doing a basic capture but, if some of the additional features of the software are turned on (like viewing a vectorscope), it behaves and can happily capture without dropping any frames. (On a Turion 64 laptop with 1GB RAM).

It makes me wonder if some systems are *too* fast for the underlying DirectShow framework.

[LAJ_26]

I've just tried the program and played around with a few features like vectorscope but I haven't been able to get any improvement I also tried it with a 20 second time delay thinking that it would perhaps create a 20 second buffer in RAM in case it's my HDD causing the problems, but that didn't work either.

[JohnnyMalaria]

I also tried it with a 20 second time delay thinking that it would perhaps create a 20 second buffer in RAM in case it's my HDD causing the problems, but that didn't work either.

It does create a buffer in memory.

Given the problem shows up on all the capture tools you have tried, there is clearly something tied to either the MSDV driver and/or DirectShow framework.

In our software, when you connect to the device, do you see live video in the input window.

Also, if you configure it to display the output in a window (rather than create an AVI file), do you see any problems - e.g., jerky video, poor audio etc.

What audio hardware do you have?

One thing that DirectShow needs is a reference clock to co-ordinate everything with. By default, it will use the audio hardware for this. For DV input, though, it will try to use the Firewire interface. Perhaps there is something up here.

You can test this with GraphEdit - a utility that Microsoft provide with their Software Development Kit (SDK). Technically, it is only available with the SDK but there are other sources for it (a Google search will help and there is a link on this forum). With this tool, there are ways you can change the clock and try a variety of options to troubleshoot your problem.

If you do download it, let me know and I'll post some suggestions of things to test.