VirtualDub audio speeds up, JVC rewind slipping?
 

Hello all! I'm having a couple of issues with my capture workflow. One somewhat minor, and one very major. First, my JVC SR-MV45 is having a curious rewind issue. It seems to slip and labor while rewinding, but not while playing or fast-forwarding. I've attached a video with the behavior of all three, so if anyone knows anything about that I'd be appreciative, but it isn't that big of an issue as I have other decks I can use to rewind. The deck has been serviced and refurbished by lordsmurf and then minor repairs by me (a gear jumped out of place) so the belt shouldn't be the source of the issue.

Next, VirtualDub is ruining the audio of my captures. I'm new to it (and in my opinion its interface is pretty poor), so maybe this is an obvious fix, but it's warping the audio of the captures. I've confirmed that it does this on both VCRs I have, and on both dongles (an ATI and an Elgato) so all I can assume is that it's down to Vdub. It's not the tape, because when captured through the Elgato proprietary software, all is good (other than the bad quality of the capture :D). Anyone have any ideas on this? I've attached a few test recordings of a marching band performance to show the problem, even the non-musically inclined should be able to hear it.

Any help would be appreciated!

Attachment 17548

Attachment 17549

Attachment 17550

Attachment 17551

Attachment 17552 (Example of FF, Play, and Rewind, I'll note that it was slipping quite a bit less than it had been in this recording, but the speed is very inconsistent and slower than I'd expect)

Screencap the VirtualDub timing settings. Probably all it is.

The VCR may be narrowed down to teeth on gear somewhere. Tape transport movement is caused/enabled by multiple points along the path, so where/why is the troubleshoot.

I assume it should be the second option rather than the third?

-- merged --

Clearly not! Tried with the second option and got an overall desync of 356 seconds in a 656 second capture :eek:

Are you properly using lossless capture codec, not uncompressed?

Try these for your timing here:

I'm using HuffYUV 32 bit multithreaded, I set it up when I first started capturing and then again today (vdub likes to erase settings when restarting) based on forum instructions, it's outputting a file encoded in HYMT just fine, so I'm trying with those settings now. No sync errors so far. Thank you!

-- merged --

Alright, follow-up question... Looking at some captures again today I noticed that the audio was desynced by quite a bit. I hooked the setup (minus the dvk-100) up to a composite CRT and noted that the audio is perfectly in sync, as expected. Any ideas what the cause for that could be? I can't imagine the broadcast-grade chroma-key box is doing it. Do I need to capture audio separately of the ATI usb dongle?

Multithread Huffy isn’t recommended. The original 32 but version of Huffy is recommended. https://www.digitalfaq.com/forum/vid...y-install.html

Do not use MT, only original.

I switched to lagarith because it seems to be better supported on the Mac side of things (although neither huffyuv nor lagarith seem to be very commonly supported).

Have to figure out the audio desync issue though.

Just be careful with Lagarith, there are byte order issues sometimes, corrupted video frames.

Computer hardware issue is potential here.
Are you trying to capture to OS drive? Or to dedicated 2nd/data/capture drive?

Capturing to OS drive, although it's not dropping many frames, and it's an ssd so it shouldn't have issues with bandwidth. The computer itself is a bit older, but considering the ATI dongle itself is decades old, I can't imagine the 4-core CPU matters too much. Is it really just background operations by Windows somehow messing up the audio track but not the video?

SSD isn't faster than HDD when it hits a cache wall.

CPU hasn't mattered in a decade now, for analog SD capture.

Windows "does stuff" in the background when online, especially newer Windows OS.
What are your full computer specs
Everything. RAM, CPU, graphics, SSDs, etc. Brands, models, speeds, size, etc.

Dell Optiplex running windows 7 SP1 with:
i7-3770 @ 3.4 GHz
Intel HD Graphics 4000
8 GB of ram, not sure what model, not really interested in opening the case at the moment to check, it shouldn't really matter, although notably it's going to be slow with how old this machine is.
Kingston 120 GB ssd (small but it only houses the video files for the time that they're being captured, then it's moved to networked storage. I think it's this. It's probably a little slower than preferred but perfectly fine for the bandwidth it's working with. I can try and find a better one but without buying something new all the SSDs I have are in use, M.2 form factor, or quite old. Past that it's hard drives but if you think that will solve the issue, I've got many extra drives I could toss in there.

Doesn't really help answer your question, but I just picked up a Quad Core i5 Dell 7010 Optiplex locally with similar specs. They can be had on ebay for under $75 shipped, just bring your own SSD. I was able to install XP 32bit on it. Interestingly, Dell lists it as XP compatible and all of those drivers are downloadable, but for some reason I was getting an error of "this is not a valid win32 application" for literally all of the provided drivers. Spent like 2 hours trying random drivers probably meant for other systems and eventually found ones that seem to work, or at least there's nothing shown as being "without a driver" in device manager now.

The 7010 is somewhat unique (or maybe it isn't unique and I'm just impressed at the value haha) in that you can install XP on it, has native USB 3.0, it has 3 PCIE slots + 1 Regular PCI slot on the "MT" version which means "mini tower", and accepts full height PCI/E cards. So you could use something like a Turtle Beach Santa Cruz card in the PCIE for a sound card if you don't like the onboard Realtek and you could use one of the PCIE slots for an AIW PCIE series card. My frustration with the PCIE AIW Cards is that their board can get rather warm compared to similar AGP variants, but that was while also using it "as a graphics card." I'll do some testing to see if when you only use it for capture and use the onboard graphics for display if it does any better in terms of heat output.

Soooo if you are feeling adventurous, you could try installing Windows XP 32 bit which may have fewer compatibility issues when it comes to the capture/virtual dub use - I'd probably recommend installing it on a different hard drive so you can go back to what you have now just by doing a drive swap back.

Also keep in mind that XP 32 bit is going to limit your usable ram to 3.5GB, but that's probably much more than enough. These days you can get 480GB SSDs for under $30 on Amazon, so might be worth a try if you're feeling adventurous.

I've got an optiplex 9010, I originally had XP on it but it was just so hard to work with, the main issues being network drivers and random bluescreens. Windows 7 has been running smoothly, and I think this issue is down to vdub being janky or the ATI 600 not capturing audio right. Not sure.

This is likely the weak link. Kingston is budget, 120gb is not enough space. You're better off using a 1tb+ SATA hard drive.

That motherboard/CPU/RAM is fine, drives fine, but the case is loud wind tunnel POS. De-case the system, and put in a standard ATX cases, with better/quiet/standard PSU, better/quiet/standard CPU cooler. The motheboard uses proprietary cables for power/fans/etc, but Harbin Repair made adapters for it (or you can DIY from Harbin's free instructions, but you waste wates lots of time to save little money).

You can build better systems, but it's a better than most random boxes.

- It's not the ATI.
- VirtualDub is not "janky", but actually some other computer hardware, drivers, and/or OS are.

There's zero reason to even install network drivers on an offline capture system. Just because Windows says "Found new hardware!" doesn't mean you have to acknowledge it on boot. The yellow exclamations in Device Manager are fine and normal.

There's something wrong in your hardware, or the OS, or the settings, you just haven't found it yet.

I'll put a spare drive in there today and see if that fixes it although I'll keep my doubts for now :P

If I recall it doesn't use standard ATX spacing for the motherboard mounting. It's been pretty quiet, the VCR running is often louder. I don't see any reason to spend more money when it works fine.

Unless your main storage is networked :)
I'd rather not do the extra 4 steps of copying it off the capture box to a usb stick, into another system, and then to the network.

-- merged --

Captured to an HDD today, still getting about a half a second of desync by my rough estimate. Not much but it's enough to be noticeable. This is the same across the whole file, so it's not warping like it was before.

Removable drive. ;)

Verify: internal SATA, not extenal?

Yep. Internal SATA. Still booting off the SSD but I can't see why that would be an issue as it has enough RAM to not use the swapfile and everything necessary should be in RAM.

-- merged --
Tried a different setup today - Plugged video into the ATI but plugged audio into the integrated chipset audio on the motherboard, probably not the highest of fidelity, but the audio is synced up perfectly.

It's definitely setting somewhere. Check the "timestamps for preview" option.

But if that workaround works, you can try it. :)

I think I'll just go with it. It can do 96kHz 16 bit, the ATI does 48, so I don't think it's any reduction in quality. No distortion beyond that of the tape itself that I can tell.