TMPGenc audio pop when join MPGs

[relight]

Using MPEG Tools in TMPGenc to simply join 2 MPGs together to create a new MPG. But right where the transition is, it always makes a very brief, high-pitched audio pop. Anyone know why? I tried changing the end of the first mpg and the start of the second mpg, and deleted one frame from each, but that didn't help.

That's my main question but I'd also like to know if when making a new MPG from joining 2 MPGs, is there a quality loss? IE, does TMPGenc re-encode the frames or simply copy them?

[BJ_M]

is the bit rate and sample rate of the audio portion the same ?

it doesnt re-render - just conjoins them .. no quality loss

[relight]

thanks for your reply.

yes, the bit rate and sample rate of the audio and the video portions are identical.

[sporlan]

I have tried this joining many times and gave up their is always a popping noise for me even when all files were done the same . I have tried using nero and setting the pause to zero but their is always a skip between the different tracks

[BJ_M]

have you tried doing audio and video seperate and then muxing back together ?

also - vitec dvd tools does a excellent job of file joining or editing .. it can even edit ac3 files. works on any type of mpeg.


Maestro can also edit and join mpeg and audio files .. does an excellent job also if the source files are dvd source..

other tools : m2 edit pro , wobble mpeg-vcr , but hese dont work as well

[weeyoo]

Use too lame plugin to encode the audio, i found that it curest the popping sound.

[relight]

okay guys thanks for the suggestions, i will have to try those tonight.

BJ_M, do you have links for those other programs you mentioned? i have not heard of them.

[SLK001]

The audio pop is caused by the fact that the audio tracks are not at "zero" (or equal) when you try to join them. This is not a TMPG problem - any program that tries to join audio like this will also have the pop. The fix for the pop is to load the audio in an audio editing program, like CoolEdit, and filter out the pops at the join locations, then remux the audio back in.

Any short duration, large amplitude transition in the time domain will result in a wideband "pop" in the frequency domain.

[relight]

alrighty, then i will try that first since it is the easiest and since it seems you know what you are talking about thanks.

[Spaceboy]

I get the same problem when joining two avi files with Nandub. Is there an easy way to filter this out with Cool Edit Pro?

TMPGEnc will demultiplex a svcd then you can load the mp2 audio file and save file as wave. Premiere will be needed to find the pops and ssqueeks and audio drop outs where files were joined, hint, drop the unjoined files onto another video track and the end will locate the joint. Cut out the bad audio and copy some air near it and paste it in.
Next time, join files at a chapter break where you can fade the audio out. Sometimes the squeek will still be heard anyway but it is less of a problem between videos.
Note: the squeek is pretty long, I missed the first big click when I did it and that part was still in the movie after I got it all back together. This seems like a lot of work but can be done in 10 min. the second time.

[burned_once]

I get this a lot. I wasted half a day trying to filter out the pop using GoldWave, only to re-encode the audio, remux the streams, and find that it had messed up the audio sync.

I solved it for my own purposes in two ways:

1. When encoding the clips in TMPGenc, use the source range filters to set the first clip's endpoint and the second's start point to a spot where the audio is at zero. The source range filter displays a graph of the audio to help you find a good spot. This works great, but is no help if there's constant sound (like a music background).

2. If no zero is available, use the Audio filter when encoding the clips in TMPGenc. Set the first clip to fade out in a short time (e.g., 100 msec) and the second clip to fade in. This produces an artificial zero which is hardly noticeable, a vast improvement over that shockingly loud screech!