Audio lag on Xvid file

zombie woof · 05-10-2007, 00:23

Can somebody help me? I have an Xvid file that plays perfectly on my PC using several different players however on my A2 the audio lags by about 5 seconds. I checked out the content using Gspot and it reports the video encoder as XviD 1.2 SMP and the audio as mp3 VBR 48 Khz 107 kb/s but with no other details. Could this be a problem with the new LAME encoder?

mssx · 05-10-2007, 01:54

AFAIK VBR audio does not play too well in videos. so try converting the audio only to CBR. that might help

MCSmarties · 05-10-2007, 09:24

Hmmm... all my movies have VBR soundtrack and work fine on my A2.
Audio synch is a very common and annoying problem, but it's puzzling that it would be off-synch on the A2 and not on the PC...

Just to get the obvious out of the way, did you check that your audio play rate is 1.0x ?

You can indeed try to convert the VBR to CBR. I would recommend you extract the soundtrack as uncompressed PCM first
(this will take A LOT of space) and then compress it to CBR.
You can also try to load the movie in VirtualDubMod and re-write the header,
but make sure to have a backup first. This may screw up the sound even more...

omjeremy · 05-10-2007, 09:40

I just went through fixing this.

For a constant delay, See: http://www.gromkov.com/faq/faq2004-0064.html

The first method listed doesn't work in other programs, so use AviMUX. However, you can use the first method listed to find out how much the video is out of sync. Then with that number, you can change the delay in AviMUX.

Yet, after doing this, I have had an odd problem where my A2 says the index is broken and have yet to figure out how to fix this.

If the delay varies throughout the video, followMCSmarties method of extracting the adio and recompressing it all in VirtualDub. It works great, but most likely will give a delay.

Kodai · 05-10-2007, 10:13

I've seen this problem on several Xvids recently. Sending them through JetAudio clears up the problem.

zombie woof · 05-10-2007, 14:47

Thanks for the help everyone. What a friendly forum this is!

I will strip out the audio and re-code it.

I'm still curious as to why the PC handles the file without problems though.

zombie woof · 05-10-2007, 14:50

Quote:

Originally Posted by omjeremy

I just went through fixing this.

For a constant delay, See: http://www.gromkov.com/faq/faq2004-0064.html

The first method listed doesn't work in other programs, so use AviMUX. However, you can use the first method listed to find out how much the video is out of sync. Then with that number, you can change the delay in AviMUX.

Yet, after doing this, I have had an odd problem where my A2 says the index is broken and have yet to figure out how to fix this.

If the delay varies throughout the video, followMCSmarties method of extracting the adio and recompressing it all in VirtualDub. It works great, but most likely will give a delay.

I've come across this before, I think it's due to telecine pulldown.

Thanks for the help.

MCSmarties · 05-11-2007, 10:25

I'll be really curious to see how you manage to clean this up.
It's just so weird that the lag would only happen with the A2!
Unless it's due to a LAME VBR -new problem...?
(That's kind of an inside comment/joke)

zombie woof · 05-17-2007, 00:46

I managed to fix this file very simply. I ran it through Virtual dub with video set to direct stream copy and audio on full processing. I re-compressed the audio to 128 kb/s 44 kHz with constant bit rate. That was it, it took a few minutes.

However I'm still curios as to why the first one failed.

omjeremy · 05-17-2007, 08:58

I've noticed that when I used Yet Another Avi Info to set the delay in the file, it only makes a difference when I play it on the A2. If I play it on my computer, it plays as if I never changed anything. Weird...

05-10-2007, 00:23	#1
zombie woof Member Join Date: Mar 2007 Location: UK Posts: 41	Audio lag on Xvid file Can somebody help me? I have an Xvid file that plays perfectly on my PC using several different players however on my A2 the audio lags by about 5 seconds. I checked out the content using Gspot and it reports the video encoder as XviD 1.2 SMP and the audio as mp3 VBR 48 Khz 107 kb/s but with no other details. Could this be a problem with the new LAME encoder?

05-10-2007, 01:54	#2
mssx Senior Member Join Date: Apr 2006 Location: Coventry, United Kingdom Posts: 510	AFAIK VBR audio does not play too well in videos. so try converting the audio only to CBR. that might help __________________ Cowon A2 + Sennheiser IE6

05-10-2007, 09:24	#3
MCSmarties Senior Member Join Date: Nov 2005 Location: Pittsburgh, PA Posts: 677	Hmmm... all my movies have VBR soundtrack and work fine on my A2. Audio synch is a very common and annoying problem, but it's puzzling that it would be off-synch on the A2 and not on the PC... Just to get the obvious out of the way, did you check that your audio play rate is 1.0x ? You can indeed try to convert the VBR to CBR. I would recommend you extract the soundtrack as uncompressed PCM first (this will take A LOT of space) and then compress it to CBR. You can also try to load the movie in VirtualDubMod and re-write the header, but make sure to have a backup first. This may screw up the sound even more... Last edited by MCSmarties; 05-17-2007 at 09:49..

05-10-2007, 10:13	#5
Kodai Member Join Date: Dec 2006 Location: Mipple City Posts: 89	I've seen this problem on several Xvids recently. Sending them through JetAudio clears up the problem. __________________ As far as we know, peanut butter has no effect on the rotation of the Earth. -- Annals of Improbable Research

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05-10-2007, 09:40	#4
omjeremy My A2 Died :( Join Date: Apr 2006 Location: USA/Chile Posts: 392	I just went through fixing this. For a constant delay, See: http://www.gromkov.com/faq/faq2004-0064.html The first method listed doesn't work in other programs, so use AviMUX. However, you can use the first method listed to find out how much the video is out of sync. Then with that number, you can change the delay in AviMUX. Yet, after doing this, I have had an odd problem where my A2 says the index is broken and have yet to figure out how to fix this. If the delay varies throughout the video, followMCSmarties method of extracting the adio and recompressing it all in VirtualDub. It works great, but most likely will give a delay.

05-10-2007, 14:47	#6
zombie woof Member Join Date: Mar 2007 Location: UK Posts: 41	Thanks for the help everyone. What a friendly forum this is! I will strip out the audio and re-code it. I'm still curious as to why the PC handles the file without problems though.

05-11-2007, 10:25	#8
MCSmarties Senior Member Join Date: Nov 2005 Location: Pittsburgh, PA Posts: 677	I'll be really curious to see how you manage to clean this up. It's just so weird that the lag would only happen with the A2! Unless it's due to a LAME VBR -new problem...? (That's kind of an inside comment/joke)

05-17-2007, 00:46	#9
zombie woof Member Join Date: Mar 2007 Location: UK Posts: 41	I managed to fix this file very simply. I ran it through Virtual dub with video set to direct stream copy and audio on full processing. I re-compressed the audio to 128 kb/s 44 kHz with constant bit rate. That was it, it took a few minutes. However I'm still curios as to why the first one failed.

05-17-2007, 08:58	#10
omjeremy My A2 Died :( Join Date: Apr 2006 Location: USA/Chile Posts: 392	I've noticed that when I used Yet Another Avi Info to set the delay in the file, it only makes a difference when I play it on the A2. If I play it on my computer, it plays as if I never changed anything. Weird...