Audio synch problems...is theor a good way to fix it?

[Werble]

I have been capturing AVI files from digital cable but the longer captures always have audio synch problems. I have searched the forums and have tried to either stretch or compress audio unsuccessfully. Is their an easier way to correct audio synch problems without having to do too much work? It's becoming exhausting and I am really starting to believe that getting a TIVO might be the best way to go. Can ANYBODY help with audio synch? Thanks.

[Almost Human]

More info is required. Take the time to fill out your profile.

Capture device?
Number and size of hard drives?
Program using to capture?
Capture compression used?
Can you use VirtualDub?
What kind of sync problem?

We would be glad to help, but are not (generally) mind readers.

[Werble]

Capture device? Nvidia geforce III w/ s-video input
Number and size of hard drives? two (20 gig and 80 gig maxtors)
Program using to capture? virtualdub, virtual vcr, mainconcept encoder
Capture compression used? huffyuv, picview mjpeg
Can you use VirtualDub? yes
What kind of sync problem? beggining is fine but as the capture continues the audio lags behind the video. You see people mouth words then the audio of what they are saying follows.

[jameshgross]

Ask your self this question: What does it mean if the audio is out of sync in computer terms?
Are you running AV SW?
Have you checked your system for spyware?
Something is using processor cycles that should be used to process the audio.

[Almost Human]

Before making any changes, like cutting out unwanted sections:

Open your AVI in VirtualDub.

Under "Video" select "Frame Rate".

In "Source rate adjustment" select "Change so video and audio durations match, OK.

Under "Video" select "Direct stream copy".

Under "File" select "Save as AVI".

Save to the other hard drive.

Check your new AVI's file info and you will see that the audio and video are the same length.

Go ahead and cut the unwanted sections.

Save back to the original hard drive making sure the video "Direct stream copy is still checked".

This will probably produce an AVI with a frame rate of 29.968 or thereabouts which is still within the normal parameters of most encoding programs (TMPGEnc has no problems with it).

[steptoe]

Have a look at this tool available on here, it seems it may go some way to addressing the common problem of audio synch

https://www.videohelp.com/tools?tool=566#comments

[FulciLives]

Most video capture programs have what is called a MASTER STREAM

Set the master stream to AUDIO

That is what works for me.

I use TheFlyDS to capture. Anothre popular capture program that works in a similiar way is iuVCR

You might also want to try VirtualVCR and the "dynamic resampling" method. This is said to work well for most people although it doesn't work for me after trying it many times.

I guess it all depends on your system and how things interact with each other which often times is nothing you can control.

- John "FulciLives" Coleman

[Werble]

Hi guys,


FulciLives, I had tried iuvcr last night on what I read from Lordsmurfs website. You are correct in that the master stream needs to be set to AUDIO. The avi I captured (which is almost 2 hours long) came out just fine. But, when I import the avi into adobe premier, the audio is not in synch with the video again. So if I try to convert the avi to mpeg2 the result will be out of synch. If I import it into vegas 4, it appears to be fine. I would continue to use vegas but I like premier since I can then use the Mainconcept mpeg2 plugin which yeilds far better results in terms of quality as compared to the MC encoder foud in vegas. So there must be something in premier which is making it out of synch. Does anyone know if there is a setting in premier that will keep the audio and video in synch as it is in the original avi file? This is really starting to drive me nuts. Thanks.

[Werble]

By the way steptoe, thanks for the link but I feel there has to be a better way of getting synchronization withought having to go through all these little proggies. It's just become way too time consuming for all that. That's why I say it's just easier getting a TIVO and do away with all the extra little steps.

[Werble]

Sorry, I was reading the post backwards so I am commenting on ALmost Human. I tried what you said but then that will leave me with spending about another hour just doing what you suggested. ALmost, is there a way to set up virtualdub with the settings you mentioned before capturing so synch will be done as it is capturing or does this process have to be done after the capture? Seems a wate of time to have to do the process you mentioned after every capture. I am sure it works but for those of us with limited time it can be very frustrating ( lucky for me I have time this memorial day weekend). Thanks for all suggestions.

[Almost Human]

Werble

I have been trying different methods and programs for almost two years, and nothing works satisfactorily. After many discussions it became apparent that NOBODY knew why this happened or how to keep it from happening in the first place.

The method I listed works 100% of the time and only adds 15 additional minutes to the process per hour of video if using two hard drives (takes 35 minutes with one drive).

I cannot take credit for this, it was brought up in a discussion in this forum by someone I don't remember. Thank you, whoever you are.

[Werble]

Well from what I have read in the forums and elsewhere, there is always going to be issues with synch problems, quality problems, and other issues. To spend hours trying to get a video to be properly done is a waste of time and energy. How disappointing it is to do alot of work and then to realize that the end result is far less than you were hoping. I am giving up on this mess and getting a TIVO and hack it so that I can burn dvd's.

[FulciLives]

It seems that the best way to get around audio sync problems is to use the Canopus ADVC-100

Almost every single person that uses it praises it for the ability to have no A/V sync problems.

Also if you need to do a lot of editing your capture is in DV AVI format which is the easiest format to edit.

I capture using the PICVideo MJPEG codec (on the 19 quality setting) with 16-bit 48k Stereo PCM WAV audio. I have no problems editing my captures with VirtualDubMod but then again my captures are TV shows or movies. I just need simple "cut" editing such as trimming the start and end points and sometimes cutting out TV commercials.

Extensive editing where you ae adding effects or re-arranging clips etc. could be tricky unless it is DV AVI format.

I don't see why you need to use Adobe Premiere to edit most captures though unless it is home movie camcorder type footage.

- John "FulciLives" Coleman

[Werble]

FulciLives, I also capture vhs movies for people looking to preserve them on DVD. So obviously audio synch becomes a major issue from that standpoint. You are right , I don't need to use premier as I can use vegas but premier gives me better picture quality. As far as audio synch is concerned, my avi's are perfectly in synch to begin with but not when you import it into premier. That's when it gets out of synch.

Is there a difference in avi format when capturing using huffyuv, mjpeg, or dv avi formats as far as audio synch is concerned? If there is then maybe I have been capturing in the wrong avi format. Please let me know.

I have been considering getting the canopus advc-1394 capture card. But if my avi's are in synch to begin with and get out of synch when importing to premier, what's to say the avi captured with the advc-1394 won't get out of synch in premier also? Has anyone had an issue with that or tested that theory? I don't want to spend $200 + on something that won't fix my problem. Can someone comment on that as well? Thanks.

[FulciLives]

The easiest format to edit is DV AVI which is essentially the format Premiere and Vegas etc. are made to deal with best.

The Canopus ADVC-100 (I'd suggest this over the one you mentioned) captures analog video to DV AVI format and is known to be exceptional at keeping A/V sync.

If you MUST use Premiere then the Canopus ADVC-100 is probably the holy grail you seek.

However ...

Do not confuse editing with encoding.

You can very easily capture HuffyUV or PICVideo MJPEG and then edit these captures with VirtualDubMod. At this point you can use any MPEG encoder you wish. Premiere uses the Mainconcept MPEG encoder and there is a version of that encoder that is a stand alone version ... no need to go through Premiere. I use Cinema Craft Encoder which is only $58 for the CCE BASIC version and does just as good a job.

In short I think you are making your life difficult by insisting to use Premiere when you don't have to use it.

As for capture formats:

HuffyUV is a free codec. It uses compression but this is considered a lossless form of compression. No quality is lost by the compression.

PICVideo MJPEG is a codec you need to pay to use (I think it is $30). The benefit is that it is easier to use with a slower computer or one where HDD space is "tight". It uses compression that is considered lossy i.e., some quality is lost due to the compression. On the two highest settings (20 and 19 of which I use the 19 setting) it is barely noticeable. This is the codec I use because my computer is a tad slow and HDD space is not rampent on my system. With a fast enough computer and with enough HDD space then HuffyUV is probably the better choice though.

There are free DV AVI codecs. It uses a lossy form of compression but again this is barely noticeable. It is the easiest of all formats to edit as the DV format was designed from the ground up for such use. The only downside is that NTSC DV uses a 4:1:1 colorspace (whereas the other formats above use 4:2:2) and this can cause some loss of color information. Most people don't ever notice it. There are filters that can more-or-less "correct" the problem although that means running the final DV AVI through AviSynth or VirtualDubMod and then feeding it to your encoding application such as the stand alone version of the Mainconcept MPEG encoder or CCE BASIC etc.

- John "FulciLives" Coleman

[Werble]

FulciLives, thanks for your in depth response. It's not that I have to use premier but I feel it gives me better encoded mpeg2 quality than vegas. I would much rather use Mainconcepts stand alone encoder software but I then lose transition effects to make my videos captured from vhs look more professional and pleasing to the eyes of potential customers. Funny how vegas does not give me as much audio synch problems (almost no synch issues at all) but the video quality suffers even at the highest bitrate settings.

I tried capturing in dv avi but the dropped frames were way too many to be of any use (not using a capture card like advc-100).

If I captured in uncompressed avi format, would that also have the potential for audio synch problems? I tried it once but I had dropped frames whereas using huffy or mjpeg did not drop frames. I'll try uncompressed again if it would mean no synch issues, albeit at the expense of dropped frames and hard drive space.

[FulciLives]

FulciLives, thanks for your in depth response. It's not that I have to use premier but I feel it gives me better encoded mpeg2 quality than vegas. I would much rather use Mainconcepts stand alone encoder software but I then lose transition effects to make my videos captured from vhs look more professional and pleasing to the eyes of potential customers. Funny how vegas does not give me as much audio synch problems (almost no synch issues at all) but the video quality suffers even at the highest bitrate settings.

I tried capturing in dv avi but the dropped frames were way too many to be of any use (not using a capture card like advc-100).

If I captured in uncompressed avi format, would that also have the potential for audio synch problems? I tried it once but I had dropped frames whereas using huffy or mjpeg did not drop frames. I'll try uncompressed again if it would mean no synch issues, albeit at the expense of dropped frames and hard drive space.

You probably should just get the Canopus ADVC-100 then. No A/V sync issues and no dropped frames because it does all the encoding in the box and just sends the signal to the computer already as DV AVI

So you solve the A/V sync
You solve dropping frames (due to slow computer etc.)
You get DV AVI which should work perfect with Premiere

Sounds like a no brainer to me!

All you need now is about $250 since that's about the cheapest you will find the Canopus ADVC-100

- John "FulciLives" Coleman