VirtualDub settings for a BT878-based card

[kenmasters1976]

Hi again.

I have an old BT878 based video card that I'm using to capture some old VHS tapes. The card came bundled with InterVideo WinDVR 2.0.

If I capture using WinDVR, audio is correctly in sync with the video, but the video is not the best quality as it tends to macroblock on scene changes. Also, it deinterlaces the video by merging frames together, which usually makes the video look quite bad on scenes with movement.

So, I tried capturing with VirtualDub to get a better video quality as well as the chance to IVTC. The problem now is that I've tried all kind of settings in VirtualDub but I can't get rid of an annoying audio problem that is not necessarily sync but a random audio skip issue. Occasionally, the audio skips as when an old LP disc skips while playing. It is apparently random as sometimes it can happen like once every 20 minutes or 30 seconds after the capture starts.

I know probably the simplest answer will be to get a better capture card, but I thought I lose nothing by asking: do you think is there a VirtualDub solution for this?.

I'm capturing XviD video and uncompressed audio, but I've also seen this happen with Huffyuv video.

Thanks in advance.

[Ghitulescu]

How about reading the stickies?

http://www.doom9.org/capture/capturing_vdub.html
http://www.doom9.org/capture/sizes_advanced.html

[kenmasters1976]

I read those a while ago, I've done that before and I can't see anything that can help me with this problem. Not to mention the VirtualDub guide is quite old.

[Ghitulescu]

VirtualDub is also old, so your own card, according to your own post. :):):)
I haven't use Vdub in years, long time ago it was a separate version that kept the audio in synch, I think newer (still old ;)) versions have this already in.

But it seems to be a hadrware problem, what do you use for audio?

[kenmasters1976]

Capture card is old. I'm using the latest version of VirtualDub (1.9.7, actually; the latest is 1.9.8). As I said, if I capture with WinDVR, there's no sync nor audio skip problems. It only happens with VirtualDub. The capture card has an audio input but it also has an output that has to be connected to the PC Line-in (integrated audio, in my case), so I guess it's simply a bridge.

I used to do audio compression while capturing but then changed it to capture uncompressed audio thinking that it might be the reason, but the audio problem persists.

[Ghitulescu]

As I thought.

Can you capture long durations of audio only, not using WinDVR, but say Audacity or similar? While having some CPU load?

[kenmasters1976]

Well, I've used Audacity before to back up some audio tapes (up to 90 minutes) but, to be honest, I didn't quite check all of the resulting capture to see if it's free of audio glitches since I thought it would be OK (it was before I noted this issue in VirtualDub). I might check those Audacity captures.

As for the CPU load, I usually leave the PC capturing when I'm not using it so at most it is doing some downloads in the background.

[GrofLuigi]

First thing, which driver is it?

Second, new(ish) versions of VirtualDub have many options in Timing menu to achieve sync.

GL

[kenmasters1976]

Ghitulescu, I did a test with Audacity and recorded some audio while using the PC normally. The audio glitch did happen in Audacity, too. It happened only once -apparently- in about 23 minutes of audio, so CPU usage is not the reason for it. I'm attaching a picture. The selected area is where the audio skips. It's repeating the audio marked in red.

http://img51.imageshack.us/img51/1694/audacity.png (http://img51.imageshack.us/i/audacity.png/)

So, is it an issue with the integrated audio?. If so, is it possible to solve it by installing an audio card or otherwise?.

GrofLuigi, I've tried different timing settings in VirtualDub. Anyway, it seems it's not a VirtualDub issue after all.

[Ghitulescu]

Ghitulescu, I did a test with Audacity and recorded some audio while using the PC normally. The audio glitch did happen in Audacity, too. It happened only once -apparently- in about 23 minutes of audio, so CPU usage is not the reason for it. I'm attaching a picture. The selected area is where the audio skips. It's repeating the audio marked in red.

So, is it an issue with the integrated audio?. If so, is it possible to solve it by installing an audio card or otherwise?.


Buy yourself an used DVD-Recorder of the first 2 generations (Pio, Pana but no Philips) with the highest model number you can find, for the same price as the new audio card.

If you capture at highest quality level (XP+, XP etc.) you can use the MPEG-2 files like the normal AVIs, it won't make a difference because the source is VHS.

[zilog jones]

Try updating your audio drivers. What specs are your PC? Have you monitored CPU and memory usage (e.g. with Task Manager) when capturing? If there is too much load on either of these I guess skipping like this could happen.

[Ghitulescu]

Try updating your audio drivers. What specs are your PC? Have you monitored CPU and memory usage (e.g. with Task Manager) when capturing? If there is too much load on either of these I guess skipping like this could happen.

But not on audio ... ;)

[kenmasters1976]

OK, thanks a lot Ghitulescu. I guess I'll consider your suggestion to buy a DVD recorder.

Thanks again.

[zilog jones]

But not on audio ... ;)

Are you sure about that? I know audio requires a lot less bandwidth than video and I haven't experienced this myself, but if there's some serious bandwidth limitation what would happen? I suspect dodgy drivers or some other software interfering more than that though.

[kenmasters1976]

zilog jones, memory and CPU usage are not the problem, I've checked that. I have the default audio drivers that came with my machine. I'll see if there's any updated drivers and try with those. I lose nothing. Thanks for your suggestion.

[zilog jones]

What audio interface is it? What do the drivers call it? Some Realtek drivers can be pretty dodgy. The drivers that came with the PC are often ancient.

[kenmasters1976]

Windows' Device Manager says it's a CMI8738/C3DX Audio Device.

[zilog jones]

Try Windows Update to see if has newer drivers, or go to your computer manufacturer's support website (or motherboard manufacturer if it's a generic/self-build).

CMI's own downloads are here: http://www.cmedia.com.tw/EN/DownloadCenter_Detail.aspx?pserno=0&dtype=ALL
But it only lists CMI8738-LX, -MX and -SX so I don't know which (if any) are suitable for yours.

[kenmasters1976]

Yes, I went to C-Media's website and downloaded the CMI8738 driver. It works with my hardware even though it's not listed with that name. Now I'll make some tests to see if the updated drivers help to solve this issue.

Thanks for your help. I'll post back when I have an answer to whether it solves the problem or not.

[lordsmurf]

Age has nothing to do with quality of the method. VirtualDub is not always the best software for BT8x8 cards. Sometimes you're better off with WDM-native software, like iuVCR. See the guide for using iuVCR to capture video on a computer (http://www.digitalfaq.com/guides/video/capture-avi-iuvcr.htm).

I don't necessarily agree that you need a "better capture card" or that you should jump ship to a DVD recorder (especially NOT an old error-prone Panasonic DVD recorder (http://www.digitalfaq.com/reviews/dvd-recorders.htm), which has poor MPEG encoding quality).

I'd skip on audio drivers, too -- I doubt that is the issue. The real key to quality audio capturing is to use a dedicated PCI audio card, not something embedded in the motherboard. Turtle Beach or SoundBlaster cards work best.

[zilog jones]

The real key to quality audio capturing is to use a dedicated PCI audio card, not something embedded in the motherboard. Turtle Beach or SoundBlaster cards work best.
There are lots of good USB audio interfaces too - they can be more convenient as you can have it in an easily accessible place on your desk (as opposed to having to go around the back of your PC to connect inputs), they often have RCA stereo inputs (less chance of stereo crosstalk like with some 3.5mm jacks) and often have ASIO support (not really useful for video capturing but can be good if you do other audio recording).

I have an Edirol UA-1EX (around $80) and am very happy with it. There's also the Behringer UCA202 which is a lot cheaper (around $45) - it only does up to 48 kHz sampling but that's plenty for any VHS tapes or other analogue video.

[lordsmurf]

I still shy away from USB. USB all runs through the CPU, and some chipsets are terrible at the dataflow. You can end up with the same sort of issues with USB audio, as the person here is already getting (glitches, sync issues, missing audio, pops/cracks, etc). USB video can be a pain, too. It really depends on the cards, drivers, OS, USB chipset and CPU. From experience, USB works about 33% of the time. The other two-thirds not so much.

[zilog jones]

In this day and age I don't think it's really an issue any more, certainly not for just audio. I've never had any issues with this, even recording at 24-bit 96 kHz using ASIO drivers (which I assume would be more demanding than WDM/DirectSound). Maybe if you have some cheap junk motherboard with an SIS chipset (you'll probably have a myriad of other problems too), but not anything half decent.

[lordsmurf]

I've seen it even on preferred chipsets, good systems. The USB bus simply doesn't perform well at anything requiring sustained connectivity, be it audio/video capturing, or even large file transfers. It wasn't designed for sustained dataflow, it is a burst-based protocol.

Firewire is a different story, of course.

[Ghitulescu]

I agree on you lordsmurf concerning USB issues (the interfaces from renowed companies like Edirol (Roland) are FireWire for profi but USB for cheap, entry level).

Concerning the DVD recorders, maybe you should say these are for US/NTSC market (http://www.digitalfaq.com/reviews/dvd-recorders.htm), in EU the things are a bit different.

Eg Pioneers: the first generation was a dream, my DVR7000 is not overpassed by any DVD recorder I've seen in my life in any mode (up to 4 hours), the next one (5100 etc) was still good, with lowest low on DVR220 that was also sold in food supermakets. Panasonics do not have in EU to care about all the NTSC "finesses" like pedestal(setup) and tint, which plague the US models. In 1-2 hours they yield a decent quality, better than most other ones, DIGA is more or less a joke (and yes, they pay a lot for good reviews). And they display power supply problems only if disconnected from mains. Philips are great, but they don't last - their optical pickup is prone to errors (the irony is that most HiFi/HiEnd CD-players also use their pickups) - it's probably the only manufacturer that is native PAL. JVC are not so good in image, probably I should also check their professional line (like JVC SR-DVM700E or similar). Good reviews had the Toshibas, I have no experience therewith.

The first generation in EU was Pio DVR7000, Philips DVR1000 and Panasonic DMRE20.

Although I advise people to stay away from Chinaware, I still consider that the average Joe can obtain more than decent quality from any DVD recorder if set in 1h mode.

It's a delicate balance between the expectations (quality awareness), the budget (that dictates the hardware) and the source.

[lordsmurf]

I still consider that the average Joe can obtain more than decent quality from any DVD recorder if set in 1h mode.
Yep. It may retain all the noise of the source, but at least it won't add more digital noise in the process. XP and that's it.

SP mode is often worse than 3-hour and the same as 4-hour mode on some machines. Wrote this last year, on the topic: http://www.digitalfaq.com/forum/showthread.php/sp-mode-best-1507.html -- SP mode DVD recorder video quality isn't very good (http://www.digitalfaq.com/forum/showthread.php/sp-mode-best-1507.html).

JVC's 2004-2006 models have the LSI Logic DiMeNsion chipset, which removes chroma noise. Very important for top quality VHS to DVD work, especially if using inferior VCRs. The in's and out's of DVD recorders are listed at http://www.digitalfaq.com/reviews/dvd-recorders.htm -- info on the best DVD recorders and reviews (http://www.digitalfaq.com/reviews/dvd-recorders.htm).

Some DVD recorders are better than capture cards, some worse, some the same. It really depends on the card and the recorder (and the chipsets involved in both -- it's not just about brand!).

Panasonic's machines from 2002-2005 were plagued by inferior noisy video encoding, especially at 352x480 resolutions, and AC3 streams that just didn't work well when edited or re-authored. It's was blocky junk, most of the time. Even at XP mode, it was lackluster. The Diga tech was all crap -- 720x480 beyond 2 hours was idiotic -- but at least 1-hour and 2-hour improved over previous generations. Many of the machines suffered luminance problems, too, and NTSC models sometimes had observable chrominance issues.

The main different between Europe/Asia/Aus/S.A. and North America was IRE. Other factors tended to be identical, such as grainy encodes. A PAL Panasonic was equally crappy compared to the NTSC model, sans IRE problem. Because sources tend to be all over the map, as are DVD players and TV sets, the IRE issue is very muddy. It's overblown a bit, and I find it to be a non-issue, excluding the worst machines (those early Panasonic E20 and E30 were awful, IRE sometimes at 15-30 range!!! Whites way off too!!! Ack!). In the case of JVC's IRE problem, it can even vary unit to unit, it was not universal to the model.

(Anybody reading this needs to NOT confuse E20 with ES20, just FYI. Different models, years apart.)

[kenmasters1976]

Wow!, a lot of information worth noting here. I'll keep that in mind.

For now, I just wanted to comment that updating the audio drivers apparently helped. It's too soon to tell for sure, though. If it doesn't really help, I might try with a SoundBlaster dedicated PCI audio card if I can borrow it from my brother.

Thanks for your comments.