TMPEG sound problem - advice appreciated!

[Comfy]

Hi all!

I have a DivX film and on properties it says it has audio of...

MPEG Layer-3,128 kBit/s, 48,000 Hz, Stereo

But, when I put it in TMPEG and convert it to a VCD, the resulting sound is very tinny and metalic... you know... very digitised and does not have the warmth and full sound of the original.

Does anybody know why?

I have even tried converting it to a WAV file and using that in the encoding but the result is the same.

Just wondered why this particular file does this when other DivX films convert ok.

Thanks all!
Gray

[Triffid]

You need to convert the audio to 44.1 kHz. Search around the forum, you will find some info on what to do/tools to use. Probably enen something in the guides/how to's (I don't download divx's myself, so I've never had to do it, but I have read about plenty who have!)

[Comfy]

Triffid.

Thanks so much for the reply, but I reckon I am fairly decent already at converting to VCD, just this one is a problem.

The audio is...
MPEG Layer-3,128 kBit/s, 48,000 Hz, Stereo

BUt when it is converted it sounds all digital and metalic sounding.

I have even told TMPEG to use the Lame encoder for the audio but the result is the same.

I would appreciate ANY advice here.
Thanx.

[Comfy]

Triffid.

Thanks so much for the reply, but I reckon I am fairly decent already at converting to VCD, just this one is a problem.

The audio is...
MPEG Layer-3,128 kBit/s, 48,000 Hz, Stereo

BUt when it is converted it sounds all digital and metalic sounding.

I have even told TMPEG to use the Lame encoder for the audio but the result is the same.

I would appreciate ANY advice here.
Thanx.

[frenetic]

When you convert to .wav you end up with the best sound that the original file has. 128k/s @48,000khz has got to be hard on the ears to say the least.

About the only thing you can do is to run the outputted .wav file thru some audio application (eg. Sound Forge) and re-sample or noise filter it. It's the original encoder/author's fault for the quality, all you can do is pick up the pieces.

[Comfy]

Yeah, I understand what you are saying...
but, how come the audio sounds perfect in its original divx format.
I cannot understand in that case how it deteriates when converted.
Thanks.

[Rtm]

TMPGEnc needs to downsample the audio from 48000 to 44100 kHz, problem is that neither Toolame nor TMPGEnc's internal sound routines handles that very well.

Solution: Find a small program called SSRC and set that in "Option/Enviromental Setting/External Tool/Sampling Frequency Converter"

You can d/l it on Doom 9's page, just grab "BeSweet GUI 0.6b15" where it's included.

No more metalic sound when downsampling :D

[King-Of-DK]

How do i make the BeSweetGUI work with TMPGEnc? When i use it as external Sampling Frequency Converter,it says that the program can not be used as external encoder.I have the same problem with the metallic sound every time i convert avi2mpg.Can i downsample it using Virtualdub,and create a new wave that is only 44100 Khz,will that work?? Where can i get the SSRC program to work with TEMPGEnc??

[Betamax]

First you got to decode the mp3 to "plain" WAVe format. Then encode the sample to MP2 (you can use TMPGenc for the encoding -> just select the correct encoding format : 44.1Khz-224Kbit).
This mp2 can be muxed along with the avi. Whilel encoding to mpg(-1/-2) the mp2 will be muxed into the movie.

[King-Of-DK]

I have no idea what you just wrote,could you maybe write in laymans terms,i would appreciate it.I have DL SSRC and used that as external conversion tool,and it worked,only i still think the sound is metallic and noisy,i first extracted the sound with Virtualdub,and the wave file sounds very good,it is every time i convert it with TEMPGEnc that the sound goes metallic,even if i use SSRC.

[Rtm]

Dang, that's what you get for not reading before posting, somehow I got the words "GUI for BeSweet, azid, lame, WavBooster, ssrc and toolame" to mean that ssrc was included in the .zip

Well, here's the correct adress for ssrc:

http://shibatch.sourceforge.net/


Betamax: Your solution misses the point, that being that TMPGEnc and Toolame sucks at downsampling resulting in the metallic edge to the sound after converting.
Not that your solution can't be used, you just need an extra step in there, which goes like this: (the extra step in bold)

"First you got to decode the mp3 to "plain" WAVe format." Then downsample the WAVe from 48000 to 44100 in your favorite sound-editing program (Cooledit "Edit/convert sample type") "Then encode the sample to MP2 (you can use TMPGenc for the encoding -> just select the correct encoding format : 44.1Khz-224Kbit).
This mp2 can be muxed along with the avi. Whilel encoding to mpg(-1/-2) the mp2 will be muxed into the movie."

King-Of-DK: If you still think that the sound is metallic after using ssrc or Betamax's extended method, then there's another solution, this will produce a non-compliant VCD/SVCD though, start TMPGEnc, load the template you want to use for converting, then load "Unlock.mcf" in the Extra folder (this will unlock the template so you can change all the options), click settings and under "audio/sampling frequency" change 44100 to 48000.
Test the resulting VCD/SVCD in your player, if you use Nero for burning it will complain about the VCD/SVCD being non-compliant, just turn off compliance and burn, personally I always do a test burn on a CDR-W before I burn it on a CDR, saved me from making quite a few coasters , if your player doesn't have any problems with the VCD/SVCD, burn the real CD, if it can't deal with the VCD/SVCD, you're stuck with ssrc

Hopefully this covers all the bases when it comes to downsampling when converting.

[King-Of-DK]

read below

[King-Of-DK]

I still don´t quite understand what you mean.I use Virtualdub to convert from 48000khz to 44100 khz,and that works great,but then when i load the wave file into TMPGEnc,and convert the AVI using the wave as soundfile,i still get the noisy,and metallic sound,but it is better than if i don´t convert the wave file to 44100khz,but still noisy and a little metallic..

[videoguy79]

The tinny sound you hear is caused by the frequency conversion from 48Khz to 44.1 being done by a crappy algorithm, namely the Windows frequency rate converter (which is used by tmmpenc and several other programs). The Windows rate converter lacks anti-aliasing filters which result in the harmonic distortion and noise you hear. As another poster has said, use a good software editing program such as Cool Edit or Sound Forge to resample the audio down to 44.1Khz. Then you can use Tmpgenc or toolame to convert the wave to mp2. These encoders usually handle 44.1Khz material quite well, but not 48Khz or 32Khz for the reasons I stated above.

[King-Of-DK]

OK,how exactly do i do it in Cool Edit 2000,what should the sample rate be? and should i go down from 16 bit to 8 bit?

[videoguy79]

You need to go from 48Khz, 16bit to 44.1Khz, 16 bit. Don't mess with the bit-depth settings--most dvd players can only tolerate 16 bits--CD's and DVD's use 16 bit word-lengths. Save your resulting audio as one big wave file, then encode it with toolame or tmpgenc. You'll have to remux it with your video before burning it to a (S)VCD. Hope this helps.

[videoguy79]

You'll need to go from 48Khz, 16bit to 44.1Khz, 16 bit. Don't mess with the bit-depth settings--most dvd players can only tolerate 16 bits--CD's and DVD's use 16 bit word-lengths. Save your resulting audio as one big wave file, then encode it with toolame or tmpgenc. You'll have to remux it with your video before burning it to a (S)VCD. Hope this helps.

[King-Of-DK]

What is remuxing? and where in Cool Edit can i find the conversion tool?

[videoguy79]

Sorry--looks as if I am getting ahead of myself here. First, I do not own Cool Edit, so you're on your own as far as working with the program. From what I understand from using Sound Forge, all you need to do is open your audio file, go to "save as" and check off the settings I stated earlier: 44.1Khz, 16 bit, wav.
Cool Edit does not remux. "Remuxing" is another way of saying re-multiplexing. What this refers to is the fact that your video and audio are split into frames. In order for your sound to be in sync with your video, your frames have to match. Multiplexing combines the video and audio streams into one file, also ensuring that the frames match. In tmpgenc, you can either do this manually (under mpeg tools) or select your converted wave file as the "audio" portion in the encode menu. It then should convert the wav file to whatever bitrate you choose for the mp2 (224 for a compliant VCD), and multiplex it back with the video while encoding the video. I haven't gone that route in a while, so you may have to play around with tmpgenc to get it to do what you want.

[King-Of-DK]

OK,i got it so far,but why do i have to convert it tp m2p file? Why can´t i just load the convertet Wave file? I can set the quality in Cool Edit,should that be 224? And thanx for helping me.

[videoguy79]

If you're going to remux the file while you encode your video (i.e. select the big wav file as your audio source) then you don't need to convert to mp2--tmpgenc will do that for you. I would recommend going that route as it seems you might be new to this. In tmpgenc, choose 224 as your bitrate (quality) level. In cool edit, you shouldn't have to choose a quality level. . .if you do, you are doing something wrong! Wav files are uncompressed, 1411Kbps. The quality setting your are refering to is for mp3. Make sure you are saving your file as an uncompressed wav.

[King-Of-DK]

OK,now i have done exactly as you said,and i still have the problem,in fact it gets worse if i convert the wave into an mp2 file first,instead of loading the wave as audio source..

[videoguy79]

Hmmmm.. ..
For one thing, the audio will be worse if you convert it to mp2 and then tell tmpgenc to use it as your audio source while it's encoding the video. This is because Tmpgenc will take the mp2 and compress it again, which loses more data (audio compression is an asymmetrical process--the encoder does not "realize" that your audio is already compressed and will likely cause more quantitization noise and such by trying to recompress the data). So, use the wav file as your source. I take it that your wav file also results in crappy sound? I would recommend using an external sampling frequency converter (somebody posted something about such a program last night--it is a command-line program but I think there is a GUI out there for it if you are not comfortable in DOS). I know I recommended Cool Edit last night for this. . BUT I am not 100% certain if Cool Edit has its own algorithm. . so if it is using the Windows rate converter instead of its own, it will not do any good to use that program! After you have converted the audio to 44.1Khz, use toolame (an external mp2 encoder) to encode the file to 224Kbps mp2. This is what a standard VCD uses. Them, after your video is done encoding (when you encode the video, make sure you "tell" tmpgenc to only save a video stream (.mpv)), remux the video and audio streams together like I outlined in an earlier post. Trust me, this will remedy your sound problems, UNLESS of course your original Divx audio is shitty to begin with. I would have to hear the file myself to understand if that might be the problem, but I can say that a badly encoded divx audio stream will come out sounding like crap no matter what you do. Let me know if you need any more help. . I will try to post a link to that external sampling rate converter if I get a chance.

[King-Of-DK]

OK,so let me get this straight,i have to encode the audio seperate,and the video seperate,and then mix them together in the end? How exactly do i do this with TMPGEnc? I used an external encoder called SSRC,and that didn´t work either.The avi files audio track is not the problem,they sound great,it is only after i have converted the files using TMPGEnc,that the problem occurs,i will now try to use the method you just desrcibed,but i can´t se the difference,from what i am doing now,i use Virtualdub to downsample the audio track form the wave,only the wave comes out with a bitrate of 192kbps,so maybe that is the problem?? Should i extract the audio from the avi with Vitualdub as one uncompressed 48000khz wave? and then use TMPGEnc with tooLAME to downsample the wave to an mp2 file? and then encode the avi with no sound to get an mpv file?

[King-Of-DK]

Hey Videoguy,i have now used SSRC to downsample the wave to an 44100khz 224 bit mp2 file,and i have encoded just the video stream from my avi with TMPGen to a mpv file,i have then rexued them together,and it works somewhat,i still get a little noise,but it is not nearly as bad as beforecan i get it better still? the mp2 file is completely without noise,and so is the original wave file.

[videoguy79]

I know exactly what you mean. . .I once converted a downloaded DivX movie that had a sampling rate of 48Khz, which I then downsampled like I have explained in past posts. It sounded great as a 44.1Khz wav file, and still good as a 224Kbps mp2. . . .but it seemed to have picked up some noise when I remuxed back with my video. Unfortunately, I don't have an answer for that question, yet. It could be an idosyncrasy of Tmpgenc or the muxing process. (If anybody else has any ideas about this, I would be glad to hear them).