Audio video sync errors

[777sp2]

Hello Lord Smurf,
As I mentioned in the Audio forum I also am having problems with the audio sync. Here are my computor specs.

Windows XP home service pack 2
Pentium 4 Northwood H/T 3.2 Ghz 512cache proccessor
One Gig of DDR2 ram
160 Gig. sata II C: drive.
400 Gig. sata II dedicated to captures D: drive
ATI X800XT AGP All in Wonder graphics card
Recently reformatted all drives to NTSF format, only bare bones software and hardware devices installed.

I am capturing from a JVC HRS9911u S-VHS VCR

The following are test captures with the latest MMC9.08 and the recently released ATI video Driver 5.11. Also at no time did the ATI MMC software ever indicate any droppped frames with any of the captures I made. I Also had no dropped frames when I captured with the Canopus 110:

1.Captured analog source thru ATI using HUFFyuv codec. After six attempts, the captured video would always freeze anywhere from the 2 minute to 9 minute mark. The audio however would continue to be captured, although it proggressivly became out of sync.

I then tried using the various other codecs that came with ATI like "DV video" The same thing happened, video froze and out of sync. audio.

I then captured both above scenerios except this time I used the ATI TV tuner. Same thing happened, video froze and audio continues to be captured although out of sync.

I then captured the same analog video except this time I used my Canopus 110 converter. The 110 and my computer captured a full one hour of analog video with no freeze ups and perfect video and audio sync.

I then completely uninstalled the ATI 9.08 MMC softeware and the 5.11 video driver. I then reinstalled the latest ATI 5.11 video driver, however I installed the MMC version 9.03 that came with my original installation CD.

I chose custom installation and opted to only install the 9.03 MMC software. I then attempted to capture from the TV tuner.

This time I captured 40 minutes of TV using the HUFFyuv codec and had no video freeze ups. That was the good news, Unfortanately, just as all the above scenarios, the audio started out in sync. but ended up about 1 second ahead of the video by the end of the capture.
I even tried different audio settings ie 44k sampling instead of 48k sampling. Same bad result.

I can tell you that I would like to get this ATI card to work. I did some testing and comparing of the quality of the audio that was captured at 44k 16 bit stereo throug the ATI card. I then created an elementry audio wav. file using Procoder 2.0, and then burned with NERO. It blew away the same music audio that I captured with my Canopus 110 when I played them both on my stereo.

Lord Smurf I hope you can help with this one? I made a call to ATI but they were clueless. If you need more info. just let me know.

Is it correct to say that, the only thing that can cause audio sync. problems during capture are dropped frames?

Thanks

PS I never got passed the point of creating an AVI file. I played both AVI files on Windows media player as well as dropping the AVI files right on my Adobe Premiere Pro time line, both with the same bad results - 777sp2

[admin]

Give me a day or two to chew on this one.

[777sp2]

Hello Lord Smurf,

I have been doing alot of testing since my last post. This audio sync. problem is getting worse. After only about three minutes of capture the AVI file already plays the audio ahead of the video. I have played the file on media player and the premiere pro timeline with the same results. I have tried every codec ATI offers and the same thing happens. I then took the avi and burned it to DVD via premiere pro and the DVD also played out of sync.


I have an inexpensive Audigy sound blaster card.
Could there be an issue with my sound card?

[admin]

The Canopus device rarely has sync issues because it is a hardware device. That is a benefit of hardware encoding. On the other hand, hardware has a list of drawbacks too, it's not as perfect as some people or companies make it out to be.

What we have here is likely one of two known issues (maybe both!)

- HuffYUV. Sometimes this codec will lose sync on capture. I've observed it with a number of capture cards. It's fairly random. I've even seen it once on my own ATI card, but just once. Try to capture some uncompressed AVI (YUY2) video. If you need compression, maybe use the Alprysoft Lossless Codec, or try MJPEG (Morgan, PicVideo, or MainConcept). The DV you tried never works right.

- Audigy card. There are known issues between Audigy cards and video capture cards. ATI is affected sometimes. Something about those Audigy cards is demanding on the system and is a source of conflict. Usually swapping to a non-Audigy SoundBlaster, or a card made by Turtle Beach (equally as good as Creative Labs), will solve the issue. You can get any $20-40 card from that company, and it'll likely be fine. If not, just return it (so buy it local).

[777sp2]

I might have given the wrong spec on my sound card. I do not beleive it is a Creative labs Audigy card. It is a Creative labs "Sound blaster 24 bit advanced HD" card. I got it for $30.00 at Best Buy.

Also, I did try to capture wilth Mjpeg and ATI indicated that I was dropping about 12 to 15 frames every second. Every other codec I tried did not drop a single frame.

What do you think?

[admin]

Which MJPEG ?
Morgan, PicVideo, MainConcept, or another one ?

[777sp2]

I used the one in the ATI drop down list of the recording wizard called "MJPEG compressor". For some reason it is the only codec guaranteed to drop half the frames.

I am very confused as to how exactly the sound card plays a role in the capturing proccess and how it might impact the quality of the audio recording. Could you shed some light on this issue. It would help a great deal in myself possibly rsolving my own problem.

[admin]

The ATI AIW cards only deal in video. Most video cards only work with video. They only have video processors. Some have inputs for audio, some do not. If they do, the data is merely passed on to a card with audio processors (your audio card). The video and audio cards must cooperate. If one of them is "messy" or "complex" then the information may not be in sync.

ATI is a good video card. Pair it with a good audio card, and there are no problems.

Only certain hardware devices do both audio and video. But even then, there is not 100% foolproof flawless guarantee that video/audio will be in sync. The audioand video are still handled separately, even if they are on the same chip.

In fact, all audio is off to some degree. But it's in milliseconds or less, so you cannot hear or see the problem. This includes movies in theatres, DVD releases, and what you see on tv. Nothing is perfect. The goal is to make it as transparent as possible, so that you perceive no problem existing. A few days ago, in fact, I was trying to watch a movie on my local Fox station, and it was out of sync, so I changed the channel to something else.

The only way to resolve the problem is to make sure the hardware cooperates with one another. This may require trying a Turtle Beach card in the computer, rather than the Creative Labs (SoundBlaster) card.

I have no idea which MJPEG compressor you have. It could be defective, or some cheapy thing.

Try one of these:
http://www.pegasusimaging.com/picvideomjpeg.htm (trial)
http://www.morgan-multimedia.com (trial)
http://www.mainconcept.com/downloads.shtml (trial)

The trials probably add a watermark to your video. So you can't keep whatever you do with it, but you can test them out. MainConcept calls theirs by the full name (Motion JPEG Codec).

[777sp2]

Thanks Lord Smurf,

Just to clarify, can a sound card depending on factors like it's signal to noise ratio affect the recorded audio quality of your ananlog video capture?

Also what about a sound cards latency. Should I be upgrading to a better sound card with a lower latency?

Would'nt a latency problem with a sound card cause the audio to fall behind instead of running ahead of the video?

My sound card has options for how it records and plays audio, i.e. sampling rate 48k 96k and 16 or 24 bit. Would these settings matter when attempting to capture analog video and audio? If so, what should I set them to?

[admin]

Audio can run ahead of video when video frames are dropped but audio is not. ATI MMC is supposed to report frame drops, and notch out audio too, but sometimes (rare) odd flukes can cause this to not really work. I don't know that this is going on here. But that's how it usually works, when it happens.

Latency could be a problem, but most cards these days don't have latency issues. Or at least they're not supposed to.

I don't know that sampling rates or bits has much to do with it. I really don't remember what audio cards have in them. I do know DVD recorders all pretty much run at 96k 24-bit. That's really more for quality of sampling than anything else, to prevent oddities in the quality. DVD-Video requires 48kHz audio, and I always capture at that in ATI MMC.

I was really into digital audio 10 years ago (owned a Pro Audio Studio card). But I finished all my major audio projects in the 1990s, and have lost touch with in-depth technical details on audio cards these days. For the most part, any decent card these days totally annihilates the quality of even the best cards a decade ago, and those probably would have been adequate most of the time. Any $25-50 card is going to do what you want, more or less. Some don't perform as well as others, and I don't really know why (not my thing). The uncooperative cards, ironically, tend to be the whiz-bang $75-200 models that have too much junk on them.

If you have any fancy audio software running in the system tray (icons by the clock), you may want to turn it off. Some of that junk SoundBlaster installs interferes with audio more than helps it.