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| easy2Bcheesy |
| Posted: Jan 19 2009, 04:04 PM |
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Hi,
I've just transplanted across my hard disks and capture hardware into a new Core i7 build featuring the 920 CPU, 3GB DDR3 RAM and a Gigabyte EX58-UD5 motherboard.
Capturing in VirtualDub (any recent version!) presents some oddities.
Firstly, no matter how I adjust the timings in the preferences, audio rate from 48000Hz 16-bit PCM is coming in at 48470Hz. It does it with the onboard Realtek Line In, my Terratec Aureon 7.1, and even the integrated HDMI capture driver in my Blackmagic Intensity.
Secondly, based on the captures, I have reason to believe that the video may be similarly affected by running too fast (I'll need to investigate this further, but capturing a 30fps video game from the Intensity's 60fps input shows that occasionally every other frame is NOT a duplicate, whereas it is when capturing on another system).
My first question is... does any one have any clue what's going on here?!
My second question would be... are there any other Core i7 users, using my motherboard or another, able to acquire audio from any source at a standard 48000Hz?
I should point out that my previous build was using an ASUS motherboard with a QX6850 CPU and audio rate from all devices was solid at 48000Hz. |
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| phaeron |
| Posted: Jan 19 2009, 07:37 PM |
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Virtualdub Developer
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Hmmm... the audio rate is determined by a linear regression between the global clock and the audio stream length. This suggests that the time being returned by timeGetTime() is off by at least 1% in rate, which is a significant error. I'm not sure what to make of this.
Long shot, but you could try modifying boot.ini to boot with /usepmtimer and see if that makes a difference.
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| easy2Bcheesy |
| Posted: Jan 20 2009, 08:21 AM |
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That made no change unfortunately. Do you think this is likely to be an issue with just this motherboard? Or could it impact the entire Core i7 or X58 chipset? I'm trying to find other Core i7 users to test this out - you can use the screen capture video device and the wave mapper audio device and you still get the audio rate. |
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| easy2Bcheesy |
| Posted: Jan 20 2009, 02:40 PM |
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The XtremeSystems forum ran a test for me on a Foxconn X58 motherboard which indicates it's my board that's to blame. This is something of a relief. I'm not sure that changing memory timings or what-not would make much difference, would it? |
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| phaeron |
| Posted: Jan 21 2009, 04:54 AM |
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Virtualdub Developer
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That's not a very good test, unfortunately. Loading down the system with random tasks causes timing to become erratic due to competition for the disk and for the CPU, and that causes the linear regression to start to show errors. (It's the reason you don't want to do anything else while capturing.)
I'd suggest enabling the timing log during the capture and then doing a longish capture (>10min). You can do it in test mode, if you don't have the disk space to do a real capture. If you post the .csv file somewhere I can check the timings and see if you've got a consistent ramp error.
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| i4004 |
| Posted: Jan 21 2009, 04:58 AM |
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i dunno if i fully understand the issue:
is the issue just the number you're seeing, or the written file has 48470 rate?
if so, can't you just resample it to your liking?
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| easy2Bcheesy |
| Posted: Jan 21 2009, 09:17 AM |
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The first two XtremeSystems test are on an unloaded system and are bang on at 48000Hz. Getting anything like this is totally impossible on my system.
I did a timing log based on the screen capture/wave mapper device on my PC.
http://www.megaupload.com/?d=N3G7C27F |
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| easy2Bcheesy |
| Posted: Jan 22 2009, 01:09 PM |
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I appear to have fixed this issue by ramping up my RAM speed from 1066MHz to the RAM's rated 1600MHz (so much for underclocking!) and probably more relevantly, disabling the 'turbo' feature of the memory.
The relative rate is now stable at 48000-48004Hz on all audio devices. |
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| phaeron |
| Posted: Jan 23 2009, 04:46 AM |
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Virtualdub Developer
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Wow, that's interesting. I wouldn't think the DIMM clock would matter but I wonder if one of the clocks in your system was actually running at an incorrect speed (!).
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| easy2Bcheesy |
| Posted: Jan 23 2009, 06:20 AM |
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It wouldn't surprise me. I usually buy ASUS motherboards but I went cheap and got Gigabyte instead for the i7. The LAN ports (both) have already packed up, so the board's going back any way. Gigabyte have given me a beta of the next BIOS update and they admit that there are memory incompatibilities. What a pain! I'm now wondering whether the memory issues are what's affecting the LAN ports as they appear to be rapidly connecting and disconnecting in quick succession. |
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| easy2Bcheesy |
| Posted: Jan 30 2009, 08:03 PM |
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So I got the ASUS P6T Deluxe and once again I'm seeing relative audio rate weirdness - audio rate now seems to be wobbly at +/-100Hz around the 48000Hz area. Hmmm.
When I've got a bit of spare time I'll look into the memory timings in the BIOS and hopefully that will sort this out. |
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| easy2Bcheesy |
| Posted: May 26 2009, 09:50 AM |
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Months on and I'm still getting this issue. The Gigabyte EX58-UD5 is the worst i7 board for VirtualDub capture. Tweaking DRAM BIOS settings seems to help but I've just done an XP 32-bit reinstall and it's now got audio rate locked at 49000Hz. No BIOS tweaking seems to help any more. In-built re-sync in VirtualDub doesn't work either.
ASUS P6T Deluxe sees audio rate locked at 47900Hz, though I didn't experiment much with BIOS timings here.
The only board I've found in my own testing that gets a locked 48000Hz is the ASUS P6T WS Professional. This was with very tight DRAM timings.
I'm really at a loss about what to do with the Gigabyte board. Try as I might, regardless of the settings I use from within VirtualDub or in the BIOS, I can't even get a synced capture now! |
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| spapakons |
| Posted: Sep 28 2009, 06:51 PM |
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Could the bus speed be the problem? Try locking PCI to 33MHz to make sure the card is not affected. Try also changing the PCI latency. |
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| easy2Bcheesy |
| Posted: Feb 22 2010, 07:05 PM |
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A year later and I find myself facing the same problem again, this time with the ASUS P6T WS Pro board I previously had no issue with!
Some updates.
1. It only happens in Windows XP 32-bit, disappears completely in x64
2. It magically disappears when you turn off the hardware overlay, run from Preview or turn off preview window completely... back to 48000Hz.
I've tried changing about the DirectX settings in the Preferences but seems to make no difference. I have a feeling that swapping in an nVidia card might well fix it though as this is the card I used previously... |
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| Bartova |
| Posted: Oct 25 2011, 01:59 PM |
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I have the same stinking problem with my i7 based system.
I have a cheap motherboard with integrated audio.
I see the same delay happening when i record audio with other software.
And if changing motherboard dont work. What does? |
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