need advice on re-encoding audio

[neo4u]

i want to be able to re-encode the audio of my mpeg files to 48 hz from what it is now, As when i try to author my dvd using TMPgenc dvd author i got audio sync issues.

can anyone recomend a good program that will do that for me and possibly link me to a guide that a newbie will understand please

[Tommyknocker]

Hehe. What is your audio now? Wait, I'll ask Tgpo. He is clairvoyant.

[neo4u]

told ya i was a newbie :P

at present my audio is MPEG 1 Audio layer2 44100 hz stereo,224 kbs

[RabidDog]

Sorry to be a wet blanket but your audio sync issues will almost certainly not be solved by simply re-encoding your audio. Try it and see. Then search on audio sync

[neo4u]

the reason i have asked for advice in this matter was after reading dozens of posts on here.

And the best looking solution that i could see was to re-encode the audio before i let TMPgenc dvd author do it as it is know to cause audio sync problems.

[SaSi]

The fact that the audio is sampled at 44kHz makes it unsuitable for DVD and for this you MUST re-encode to 48kHz.

However, your additional problem that audio is out of sync is a totaly different problem and requires a solution.

There are several out-of-sync problems with different symptoms and different solutions.

Easy case is that the audio is linearly out of sync. This means that when you play the video, the audio is any number of milliseconds or seconds ahead or before the video. Seeking to any portion of the video shows the audio remain at the same amount of time ahead or before the video.

This is caused by mis-placing the audio and video start times. You need to shift the audio back or forth to fix it.

More difficult case is when the sync loss is not constant but increases.

Let's say that the video and audio start in sync. If for every minute of video you get an out of sync measure of (say) 3 seconds and if you seek at 10 minutes you have 30 seconds loss, it means that the capture rate of the video is different from the capture rate of audio.

(Note that I don't use the expression frame rate, as you don't have frames in audio).

The above problem is usually caused by conversions from NTSC to PAL or the other way around. Sometimes it is done accidentally, if before encoding you don't pay attention to the source video frame rate and you encode it at the wrong one.

Again, it is possible to fix the audio here (or the video), depending on what exactly went wrong.

The third case is that your out of sync measure is not constant and not constantly increasing. This is a tough one and the only case I have seen it is with bad captures. Easiest way out here is re-capture.

Which of the above matches your problem? (so we can focus and discuss solutions?)

[neo4u]

The fact that the audio is sampled at 44kHz makes it unsuitable for DVD and for this you MUST re-encode to 48kHz.



Easy case is that the audio is linearly out of sync. This means that when you play the video, the audio is any number of milliseconds or seconds ahead or before the video. Seeking to any portion of the video shows the audio remain at the same amount of time ahead or before the video.

This is caused by mis-placing the audio and video start times. You need to shift the audio back or forth to fix it.



Which of the above matches your problem? (so we can focus and discuss solutions?)

I would say that the one quoted above best matches my biggest problem.

But lets say for example i was burning an episode of a series what i seem to notice is that when i watch the original mpeg file everything is fine.

but after authoring it using TMPGenc dvd author the audio seems ok at the start but after the credits and opening titles have played the audio seems to slip out of sync.

sorry if this seems vauge description but as explained im new to this but desperate to learn

[neo4u]

Ok here is one of the things i have tried. I ripped the origimal audio from my mpeg file (41000 khz) and encoded it to (48000 khz) using mpeg encoder.

can someone please tell me what my next step would be, As when i try to put the newly converted audio back into the mpeg i still get out of sync audio and filesize is nearly 800 meg

i know im obviously still messing this up somewhere

But hey im a NOOB! thats why im here asking for help. :P

[neo4u]

Ok im trying my best here and there are so many guides its very confusing. But im not willing to give up on this.

Here is where im at now.

I have demuxed the video and audio using TMPgenc plus into seperate video and audio.

And tried to convert audio to 48000kz from 41000kz using TMPgenc plus, toolame, ssrc. But the audio then sounds like its playing at about 2 or 3 times the normal speed whe i checked it in windows media player

can someone be kind enough to maybe help me discover where im going wrong here as i have been trying to solve this(every waking moment) for nearly four straight days now