neroaac sync issue

[JLe2k]

Well i've looked around and everywhere they all say use vdubmod or itunes to convert from mp3 to wav to acc. They all don't work so let me explain whats going on. I encode my mp3 to aac and at the end of the video, its off sync for some reason. i've tried many things from google so it never worked. So please help and thanks for the help ahead of time

[tebasuna51]

- unsync constant (same at begining or end) or progressive?
- original mp3 CBR or VBR?
- original delayed with 0 pad? (use AviMuxGUI)
- audio extracted with VirtualDubMod Demux or Save Wav method?

[JLe2k]

at a point it becomes off by 6 seconds
original is cbr
don't know if the audio was delayed not my or original audio
used both vdubmod methods

[tebasuna51]

Open the avi in AviMuxGui, select, generate data source, select audio mp3, write down the delay, rightclick, extract binary.

Open the mp3 with BeLight, apply the delay and convert to aac with NeroAacEnc.

Good luck.

[Nicholi]

Open the avi in AviMuxGui, select, generate data source, select audio mp3, write down the delay, rightclick, extract binary.

Open the mp3 with BeLight, apply the delay and convert to aac with NeroAacEnc.

Good luck.
That won't show you the delay of the audio track. That box in AMG is only there to enter a new delay, not read the current one if any. Make an AVI yourself with a delay and check. Though if anyone else knows, I have always wondered what tool you would use to find delays in AVI files. Nothing I know of lists it.

[tebasuna51]

That won't show you the delay of the audio track. That box in AMG is only there to enter a new delay, not read the current one if any. Make an AVI yourself with a delay and check. Though if anyone else knows, I have always wondered what tool you would use to find delays in AVI files. Nothing I know of lists it.

I only know two methods to delay an audio and mux with video to obtain an avi file (maybe there are others):

1) The right way is insert true silence at the begining of the audio stream (like AviMuxGui can do) using DelayCut, or other tools (BeLight, BeHappy, ...) when transcoding from other format.
This method can't produce sync problems because the initial silence is always transported or recoded to new formats.

2) The VirtualDubMod (and old VirtualDub versions) method is pad with '0' the first bytes of audio streams until the equivalent length of delay is reached. The recent versions of VirtualDub use real silence with mp3 stream but still use invalid pad bytes with ac3.
You can verify these facts demuxing the mp3 or ac3 streams with VirtualDubMod and a hex editor. You can count the initial invalid bytes and convert to delay time (with nominal bitrate). Or you can use directly AviMuxGui and see the initial 'bad' bytes and the equivalent delay.
When these streams are decoded the first bytes are ignored by most of the decoders and the delay is lose

[Nicholi]

I only know two methods to delay an audio and mux with video to obtain an avi file (maybe there are others):

1) The right way is insert true silence at the begining of the audio stream (like AviMuxGui can do) using DelayCut, or other tools (BeLight, BeHappy, ...) when transcoding from other format.
This method can't produce sync problems because the initial silence is always transported or recoded to new formats.

2) The VirtualDubMod (and old VirtualDub versions) method is pad with '0' the first bytes of audio streams until the equivalent length of delay is reached. The recent versions of VirtualDub use real silence with mp3 stream but still use invalid pad bytes with ac3.
You can verify these facts demuxing the mp3 or ac3 streams with VirtualDubMod and a hex editor. You can count the initial invalid bytes and convert to delay time (with nominal bitrate). Or you can use directly AviMuxGui and see the initial 'bad' bytes and the equivalent delay.
When these streams are decoded the first bytes are ignored by most of the decoders and the delay is lose
Ahh I wasn't aware AMG actaully appended silence to the track. That's why it doesn't show any delay later when you look at the file again in AMG. My mistake before.

So when you demux (an AVI made with AMG and a delay) with AMG it still leaves in that appended silence correct? So the track is still in sync with the video.

[JLe2k]

I only know two methods to delay an audio and mux with video to obtain an avi file (maybe there are others):

1) The right way is insert true silence at the begining of the audio stream (like AviMuxGui can do) using DelayCut, or other tools (BeLight, BeHappy, ...) when transcoding from other format.
This method can't produce sync problems because the initial silence is always transported or recoded to new formats.

2) The VirtualDubMod (and old VirtualDub versions) method is pad with '0' the first bytes of audio streams until the equivalent length of delay is reached. The recent versions of VirtualDub use real silence with mp3 stream but still use invalid pad bytes with ac3.
You can verify these facts demuxing the mp3 or ac3 streams with VirtualDubMod and a hex editor. You can count the initial invalid bytes and convert to delay time (with nominal bitrate). Or you can use directly AviMuxGui and see the initial 'bad' bytes and the equivalent delay.
When these streams are decoded the first bytes are ignored by most of the decoders and the delay is lose

just a thought but doesn't this just work for a set delay, what if its a delay after a certain point. Also i tried demuxing it through vdub the newest version through save wav and converted it to aac through be happy using the nero aac but when i mux it using mp4box it still is off sync

[tebasuna51]

just a thought but doesn't this just work for a set delay, what if its a delay after a certain point. Also i tried demuxing it through vdub the newest version through save wav and converted it to aac through be happy using the nero aac but when i mux it using mp4box it still is off sync

When "a delay after a certain point" exist we have two options:

1) The delay exist playing the original file. Then we can't recover the sync automatically. We need split the audio track manually and insert silence until recover the sync.

2) Not exist async in original file. Then there are corrupt audio frames translated to silence when play but ignored (generating the async) when decoded to wav. I always recommend use VirtualDubMod to "Demux" the audio track (don't let VirtualDub decode to wav), and analyze the compressed audio track with DelayCut or similar to detect corrupt frames to be replaced with silence.

[JLe2k]

1) i know that there isn't a sync issue with the original

2) when i try this to demux with vdubmod, and run it though delay cut. it processes it and makes it so that it is 10 hrs long and when i set it to original length it sets it to 1 hr and 30 minutes. Is it just he mp3 or is there any other way to fix this. is there another alternative to delaycut? also there isn't sound after a certain time.

[tebasuna51]

I don't know what happen.

If you can cut a fragment around the problematic point and send us, maybe we can analyze and found a solution.

[JLe2k]

I don't know what happen.

If you can cut a fragment around the problematic point and send us, maybe we can analyze and found a solution.

Link to original sound file (http://www.mediafire.com/?aace3deeazj)

Link to Encoded Video + Audio File muxed to mp4 (http://www.mediafire.com/?1ns2idyyumn)

let me fix the video wrong audio muxed in

[tebasuna51]

I don't understand. Your original sound file is an aac-he 5.1 instead a stereo mp3 like you say in first post: "...convert from mp3 to wav to ac"

I need the original mp3.

The audio in mp4 is aac-he-ps (stereo) and is out of sync but you need cut the audio (then is not original frames skiped). Maybe you can cut at 1:29.

[JLe2k]

I don't understand. Your original sound file is an aac-he 5.1 instead a stereo mp3 like you say in first post: "...convert from mp3 to wav to ac"

I need the original mp3.

The audio in mp4 is aac-he-ps (stereo) and is out of sync but you need cut the audio (then is not original frames skiped). Maybe you can cut at 1:29.

sorry about that but since i've uploaded could you please look at it? Is there a way for me just to demux it from the original mkv and encode it so that it syncs up without me cutting it. If there isn't how would i cut it and then merge it so it'll sync properly

heres the link with the muxed japanese (http://www.mediafire.com/?d4my2mmjuwx)

[tebasuna51]

Your "original sound file" is a japanese aac-he 5.1 track and your "Audio File muxed to mp4" is the same track in english but aac-he-ps stereo and delayed about 70 ms.

But the video seems from other movie version because don't match at all. Sorry.

[JLe2k]

Your "original sound file" is a japanese aac-he 5.1 track and your "Audio File muxed to mp4" is the same track in english but aac-he-ps stereo and delayed about 70 ms.

But the video seems from other movie version because don't match at all. Sorry.

that's really weird because its run through nero when i demux it with mkv extract. Also thats the same video, its a dual audio mkv, is it because of the nero?

[tebasuna51]

I don't know, maybe there are video frames lost.

I can adjust a point at the begining and other at the end with a fix delay of -20.391 sec and a progressive coefficient of 0.992057, but the intermediate points remain out of sync.

[JLe2k]

I don't know, maybe there are video frames lost.

I can adjust a point at the begining and other at the end with a fix delay of -20.391 sec and a progressive coefficient of 0.992057, but the intermediate points remain out of sync.

too many problems -.- do you know anything about mencoder 0.o? that's what i run it through.

[tebasuna51]

too many problems -.- do you know anything about mencoder 0.o? that's what i run it through.

Sorry, try in video threads.

Seems is not an audio problem: original japanese track and recode english track seems equivalents (the 70 ms delay is normal in this process and near unnoticeable).