Help Converting MPEG2 With VirtualDub-MPEG2

[trickyman]

Hi,
I'm trying to convert a captured MPEG2 file to AVI (Panasonic DV codec or Huffy, not DivX or Xvid). When i import the MPEG2 file into VirtualDub the audio is horrible off sync.
What audio/video settings should i have in VirtualDub to resolve this? Is there a better program to use to convert MPEG2 to AVI?
I've checked the guides but nothing seems to address MPEG2 to AVI conversion...
Thanks

[Baldrick]

what audio settings are you using??? converting to mp3? wav? directstrream copy???

you can also try dr. divx, vidomi

[trickyman]

The audio is captured as 48KHz PCM.
Currently i'm trying just a direct stram copy

[SatStorm]

Sounds like audio offset more than 100ms

You can adjust the audio offset at Audio - Interleaving - Audio skew correction

[daamon]

Hi trickyman,

Look into DVD2AVI.

[junkmalle]

VirtualDub lets you skew the audio if it is off for some reason. On the Audio menu select Interleaving. In the "Audio skew corretion" box set the "Delay audio track by" value. You can delay or advance the audio by using positive and negative values.

[trickyman]

junkmalle,
I'll take a look at that audio skew. but i font know how the audio could have gotten offset. the original mpeg2 is perfectly synched. i dont do any editing in virtualdub, i just save as AVI and in teh resulting file is off by minutes...

daamon,
i've tried DVD2AVI. I save as AVI and all my output files are always scrambeled...

[trickyman]

I'm beginning to think that something is wrong w/ the source file. The file i am working with is 3 hours long. I;ve tried virtualdub and virtualdubmod and the audio is always off. but if i try a shorter mpeg2 clip (1 min) it seems to output to AVI fine. Does anyone know if VirtualDub has issues with large files?

[Capmaster]

Don't know. Is the audio offset the same throughout the whole capture with the longer ones? If so, then the audio skew will help. If it's not, there's little hope of getting it perfectly synced unless you spend an inordinate amount of time on it.

I had sync issues once and attempted: demux to elementary streams>convert audio to WAV>resampled the audio with a cmd line applet ...changing the length of the audio, using PVAStrumento's PTS time stamp dump as the cal factor>convert audio back to MP2>remux. I ended up with butchered, out-of-sync files :P

[trickyman]

Don't know. Is the audio offset the same throughout the whole capture with the longer ones?

No, at the beginning that synched audio is fine...
I'm gonna try to demux the audio and export it to WAV, then output the video an the AVI. And import both streams seperatly into Premiere for editing and see of they synch up....

[jyn999]

Are you converting from NTSC to PAL or PAL to NTSC? There are always issues with cross format conversions.

[trickyman]

Are you converting from NTSC to PAL or PAL to NTSC? There are always issues with cross format conversions.

Nope, all i'm trying to do is a direct conversion from MPEG2 to AVI for editing captured video.
I didnt think it would be this complicated
Of course the simplest this would be just to capture as an AVI, but when i tried that i drop frames and the audio not synched...
I'm using an ATI AIW 9600XT for capture which has a hardware MPEG2 encoder. SO i get much better quality capturing to MPEG2....

[SaSi]

I'm beginning to think that something is wrong w/ the source file. The file i am working with is 3 hours long. I;ve tried virtualdub and virtualdubmod and the audio is always off. but if i try a shorter mpeg2 clip (1 min) it seems to output to AVI fine. Does anyone know if VirtualDub has issues with large files?

Most likely the problem is with your captured MPEG file. It has to do with capture settings and the video/audio multiplexing in the stream.

VirtualDUB has no issue with large files. With large I mean 6-8 hours long. With more than 12 hours at 12Mbps capture VirtualDUB will produce an "Out of memory" error after parsing the MPEG file.

If your option to demux the audio to WAV and separately process the video doesn't work, try something else: Demux the MPEG stream into ES using MPEG tools within Tmpgenc Encoder. This will give you an MP2 audio file and an M2v video. Try using Restream with the video file to "fix broken GOPs and reset time stamps".

More importantly, try to find what's wrong in the capture settings. I have found that if the capture settings are for "DVD compliant streams" then I have no problems with audio out of sync.

[daamon]

Of course the simplest this would be just to capture as an AVI, but when i tried that i drop frames and the audio not synched...
I'm using an ATI AIW 9600XT for capture which has a hardware MPEG2 encoder.

I've had a read through and don't think you say where you're capturing from - DV cam, VCR?

If it's DV cam, by far the most reliable way to "capture" (actually, it's a transfer) to AVI is via firewire using something like DVIO, AVI_IO, WinDV or Scenalyzer Live.

If it's VCR and you're getting dropped frames / audio sync problems, perhaps something like a Canopus ADVC-100 is what you need. Check out lordsmurf's site www.digitalfaq.com for capturing.

[junkmalle]

I'm pretty sure the All In Wonder 9600XT does not have a hardware MPEG encoder -- it's doing the conversion in software. You may have to capture directly to an AVI file with HuffYUV or MotionJPEG codecs. Then convert to DV later.

I capture with a Hauppauge WinTV PVR 250 which definitely is a hardware MPEG capture device. I convert those MPEG files to AVI (Xvid) all the time with VirtualDubMpeg and never have audio sync problems.

[syeager]

ATI cards after 9500, including 9600, do use some limited hardware encoding. They use some of the GPU functionality to assist. (by the way, do not have a screen saver that uses 3d when capturing with ati. found that out the hard way. makes sense, but forgot about my screen saver as I was capturing).

You can confirm dropped frames during capture by right clicking on the capture control panel and select frames captured/dropped, instead of time recorded / remaining.

I capture with an ATI TV Wonder Pro with an ATI 9500 Pro and can capture 720x480 at 15M bit rate and only use about 60-70% of a 2GHz processor. Tried to capture at 720x480 at 8M bit rate with Compro TV card and it pegged my CPU.

[duhmez]

There is a fix for your problem, it's very easy and fast, and does not require a reencoding of your source file.

Follow this thread for fixing av sync PRIOR to reencoding. Do what this thead says and you will be good to go.
Cheers!

https://www.videohelp.com/forum/viewtopic.php?t=228458

[trickyman]

Thanks for the imput everyone.

I've had a read through and don't think you say where you're capturing from - DV cam, VCR?

daamon, in this instance the source i'm trying to capture from is an analog camcorder. I have a DV Cam as well which a use all teh time to transfur DV footage using firewire w/o a problem. Hey, wait a tick, theres an idea. I may try to use my DV cam as an analog/digital converter

I'm pretty sure the All In Wonder 9600XT does not have a hardware MPEG encoder -- it's doing the conversion in software.

junkmalle, i'm gonna have disagree w/ u on that one. I read it somewhere in teh documentation i got w/ the card. Plus, i can capture MPEG 2 video while sirfing the net, and doing other tasks w/o dropping a single frame. Once i even encoded a file with TMPGenc while at the same time capturing show off TV and still didnt from any frames.... Its gotta have some hardware support...

[ktjensen]

I still think stoik video converter with the right codecs does a better job, and faster. Only need one pass with this tool.

[ktjensen]

never mind Stoik still fails. Having audio/video synchronization issues, consistantly.