Audio/Video Out Of Synch

[jmsrickland]

One of my TV recordings that I did using a TV-Tuner adapter came out with the audio out of sync with the video. The audio lags about 5 seconds behind the video.

Is there any video editing tool that can be used to get the two back in sync?

Also, another recording turned out with the video much too fast. Anyway to edit this one and slow the video down to normal?

[redwudz]

What format is the video? VirtualDub (Mod) can change the sync offset or the video framerate for AVI files.

[jmsrickland]

The output video file from the TV-Tuner is MPEG-2 (DVD quality).

[redwudz]

I haven't tried that with MPEG, but you could probably extract the audio and add or subtract some time from the audio track, then mux it back in. I use VirtualDub Mod to extract WAV audio, then Audacity to modify the WAV. You can convert the WAV to AC3 with ffmpeggui, then add it back in when authoring to a DVD.

Or you may be able to demux it with TMPGEnc encoder and modify it with a audio editor.

There's probably better ways, but I rarely have sync problems with MPEG video.

The video with the wrong speed, you would probably have to re-encode.

[Barnabas]

Your computer specs look too low for real-time mpeg2 encoding, so if that's what you are trying to do, you are probably dropping a ton of frames.

[jmsrickland]

Your computer specs look too low for real-time mpeg2 encoding, so if that's what you are trying to do, you are probably dropping a ton of frames.

That's kind of what the tech help suppport of the TV card said. They told me to try different recording modes to see which ones it can handle. So I did some testing and made three recordings. One in MPEG-1, another in MPEG-2, and another in MPEG-2 DVD. MPEG-1 and MPEG-2 seems to come out OK but MPEG-2 DVD is the one that comes out with the audio/video out of sync and sometimes it is even where the video is zipping along very fast and the audio appears to be normal.

What I don't understand is how come I can play a DVD movie off the PC DVD drive and it looks extermely good being played through Nero, Video Studio, and other applications but when I record a VHS movie or a program from TV through the TV-Tuner card in DVD mode it comes out bad? Everything looks good if I just watch the TV; it's only when I try to record it at the same time in MPEG-2 DVD mode that it comes out bad.

This is where I think it might have something to do with the TV adapter card or it's associated software program that came with it.

What would be minimum specs for a PC to be able to handle real-time recording? I am using W2K on a 950MHz PC with 512MB RAM. Would upgrading the Video card or the Audio card or maybe upgrading the software drivers do any good or are my PC specs just too low no matter what I do?

[Barnabas]

Real-time encoding takes MUCH, MUCH more CPU power than playing back previously encoded video does.

Even on a much faster setup, capping from VHS can cause sync issues, due to the poor quality inherent with VHS tape.

You CAN get a hardware encoding card such as a Hauppauge PVR 150 or 250. With that, the Mpeg 2 encoding is done via hardware, so won't tax your system.

My system specs 2 gig cpu with 1 gig memory can handle realtime mpeg 2 encoding without a hardware encoding card.

W2K on a 950MHz PC with 512MB RAM would be too low for real-time Mpeg 2 DVD recording unless you are using a hardware encoding card. You might try capping to 352x480 rez and see if that will work. Capping to avi without real-time encoding might work on your system if nothing else is going on.

Your system would work ok for VCD's.

[jmsrickland]

I don't know what VCD is. However, I can record in MPEG-2, which I think is just a step below MPEG-2 DVD, and the output is fine. I'm sure that MPEG-2 is better than AVI which I also do not have a problem with.

Is VCD better than MPEG-2? If so I will try it but if not then I should just record in MPEG-2 then.

About how much would one of those hardware encoding cards like Hauppauge PVR 150 or 250 cost?.

I hope I am making myself clear about MPEG-2 and MPEG-2 DVD. These are record mode settings on my TV-Tuner software player/recorder where MPEG-2 DVD is at the top of the selection list and MPEG-2 is right below that.

Here are all the recording modes that I can select from:

MPEG2 DVD
MPEG2
MPEG1
SVCD
VCD
AVI

Are these in the best to worst recording quality?

I have only tried AVI, MPEG1, MPEG2, and MPEG2 DVD and only MPEG2 DVD wont record good.

[mwkurt]

record your video as avi then encode to whatever mpeg you want. I don't think that you lose anything if you capture to avi first. Once you have the avi on your pc, with the audio in sync, you should be able to encode to mpeg2 with no problem and no worries about dropped frames.
Mark

[Barnabas]

VCD stands for Video CD, and is mpeg1 compression, so mpeg 2 would be better. SVCD uses Mpeg2 at 480x480 rez, your machine might be up to that.

The hauppauge 150 or 250 will run you $100. to $200. or so. Mine was $100. after a $50 rebate.

AVI would be the best, a it's not compressed, so you would use a software encoder like TMPGEnc to encode to MPEG2 DVD format.

[jmsrickland]

Sounds like AVI then is the way to go. Gee, I sure do need to learn alot it seems.

Thanks for all your help - glad I asked.

[Barnabas]

One warning, capping to uncompressed avi format takes TONS of HD space. The Huffy codec works well, but you are going to be needing about 50 gigs, and if your HD formatting is fat32, you can only capture files up to 4 gigs. The Hauppauge would probably be your best choice given your computer specs.

[jmsrickland]

I just encountered a problem.

I recorded a TV show in AVI. When I launched TMPGEnc as was suggested, I tried to add this file in the Source mode of the program but it gave a message as such:

Invalid video file

The DVD video standard accepts the video formats below only:

MPEG-1, MPEG-2

[Barnabas]

Sounds like the size (rez) of the original file is the wrong size. Should be 352x480 or 720x480.

Did you use the wizard option? That usually sets things correctly, and tests the field order to get it right.

[jmsrickland]

Using the wizard does the same thing; gives same message.

AVI is 320 x 240.

Tuner card software wont record AVI in any rez other than 320 x 240.

I can, however, use Video Studio to load up the AVI.

So is the AVI better than the MPEG2? If not then why not just record in MPEG2 since that is acceptable with TMPGEnc?

[Barnabas]

320x240 is VCD size.

If your card has brooktree drivers, you can probably get other drivers that might allow x480 size

No reason to re-encode mpeg2 in TMPGEnc, as it's already encoded.

[jmsrickland]

OK, I got an AVI video that has the rez as stated above; ie: 720x480. Same thing with TMPGEnc.

I don't think that TMPGEnc even deals with AVI files, at least the version I have is telling me it doesn't. When I start it up even before it knows what the input file source is it gives me that message about the only formats it accepts is MPEG1 and MPEG2.

So if MPEG is already encoded then what does TMPGEnc do with them since those are the only formats it accepts or at least that is what it is telling me?

[Barnabas]

TMPGEnc DOES deal with AVI files, that's what is made for. I use it here weekly. You might have to raise the VFAPI plug-in setting priority.

[jmsrickland]

Ummm..... OK, so I need to install that VFAPI plugin. I see it's an executable so how does it get to be a plugin for TMPGEnc?