Encoders Cannot Recognize Audio Data in AVS Script?

rs008f · #1 02-24-2004, 01:21 PM

I'm converting some Divx files using a AVS script. When I load it to Mainconcept or TMPGEnc, they only recognize the video but not the audio. The audio format of the Divx file is MP3. They used to recognize it but after a series of uninstalling and reinstalling of several Divx/Xvid codecs, it's no longer working now. When I play the script in WMP, both the audio and video plays fine. What do I need to install/do to fix this problem?

rds_correia · #2 02-24-2004, 01:29 PM

Hi,
From my point of view that's not a so bad thing.
Encode the video with tmpg and encode the audio with headac3he.
The best at video and the best at audio.
Use VirtualDub to extract the audio from the DivX.
Otherwise wait for somebody else to help you.
Please acknowledge that both tmpg and MCE are really bad for audio encoding.
C ya

rs008f · #3 02-24-2004, 01:32 PM

But in the AVS script I have a Trim command which is crucial to keep the video and audio in-synch, so I need an encoder that will read the audio data of an AVS script. Can headac3he read AVS scripts?

rds_correia · #4 02-24-2004, 01:35 PM

Geez,
I didn't know that before.
No, there are no audio encoders that can read avs scripts from what I know.
But if you know the audio delay in miliseconds then you can use headac3he to accomplish the job.
Cheers

BobNET · #5 02-24-2004, 01:52 PM

Quote:

Originally Posted by rs008f

But in the AVS script I have a Trim command which is crucial to keep the video and audio in-synch, so I need an encoder that will read the audio data of an AVS script.

I edit the AVS to comment out all lines to do video processing, and leave only the Trim commands (and anything else that might change the length of the video). Then I load it into VirtualDub and select Save WAV... from the File menu. This should result in a WAV file with the same compression format as the audio track in the AVI (I'm not sure about this since I usually work with captures that contain uncompressed audio). Then I uncomment the video processing lines and load it into TMPGEnc as usual to do the video encode. You should be able to load the WAV into HeadAC3e to encode it into whatever format you want from this point...

Dialhot · #6 02-25-2004, 05:06 AM

Quote:

Originally Posted by rs008f

The audio format of the Divx file is MP3. They used to recognize it but after a series of uninstalling and reinstalling of several Divx/Xvid codecs, it's no longer working now. When I play the script in WMP, both the audio and video plays fine. What do I need to install/do to fix this problem?

Oh oh ! Big issue there !
I know someone that resintall winXP few days ago and since this time, no more audio in it's xvid->kvcd encoding. Just as you have !

We identified today that the problem wasn't the codec but avisynth !
As I never do audio with avisynth script, I never had the problem. But can you check on your side that by loading the avi directly in tmpgenc, the audio is there ?

rs008f · #7 02-25-2004, 11:58 AM

Yes the audio in the AVI is readable in TMPGEnc and Mainconcept. Maybe I should be installing all the codecs available on the internet..........

rs008f · #8 02-25-2004, 12:00 PM

CCE can read the audio data of the AVS script however........... Only TMPGEnc and Mainconcept can't.

Dialhot · #9 02-25-2004, 03:10 PM

I can tell you taht the problem is not in the codec (with tested a lot of them).
As soon as I have the solution, I'll tell you.

Note : BTW you should'nt encode audio with tmpgenc so...

rs008f · #10 02-25-2004, 03:23 PM

TMPGEnc and Mainconcept all do a decent job in stereo audio encoding, I never had problems, at least to my ears, CCE however have given some problems with audio but not all the time. It would be cool if there is an audio encoder that supports AVS scripts.

kwag · #11 02-25-2004, 03:31 PM

Quote:

Originally Posted by rs008f

TMPGEnc and Mainconcept all do a decent job in stereo audio encoding

Not at 128Kbps or lower.
And neither can do Dolby Surround, which you can do with HeadAC3he

-kwag

rs008f · #12 02-25-2004, 03:51 PM

I was wondering if the source AVI only has stereo audio at 128kpbs 48 kHz, would it be possible to convert it to a higher quality audio like Dolby Surround or AC3? I'm thinking that the weakest link applies here, so if the source audio sucks (say mono, 60kbps, 22kHz), there's really no way to improve it.

kwag · #13 02-25-2004, 04:04 PM

Quote:

Originally Posted by rs008f

I was wondering if the source AVI only has stereo audio at 128kpbs 48 kHz, would it be possible to convert it to a higher quality audio like Dolby Surround or AC3?

No, because there are no Dolby 5.1 signals to downmix to DS or DS2.

Quote:

I'm thinking that the weakest link applies here, so if the source audio sucks (say mono, 60kbps, 22kHz), there's really no way to improve it.

Yes, the result wil suck

-kwag

rs008f · #14 02-25-2004, 04:07 PM

How about converting the stereo audio to AC3? My friend told me that if I convert the stereo audio to AC3, sound comes out of all his 5 speaker system but not with stereo audio. Is AC3 same as DS2 (Dolby Surround 2)?

Dialhot · #15 02-26-2004, 05:27 AM

Quote:

Originally Posted by rs008f

if I convert the stereo audio to AC3, sound comes out of all his 5 speaker system but not with stereo audio

Your friend told you bullshit. Sorry.

AC3 is actually a digital compression released by Dolby Laboratories Inc that can handle 1 up to 6 channels.
If you encode a stereo in AC3, you will do a 2.0 AC3 stream and the sound will come out from 2 speakers only.

But... if your stereo is DolbySurround, the 2.0 AC3 will be also AND then the audio will come out from 5 speakers (DPL decoding).
But the original stereo already came out form the 5 speakers ! This is not due to the AC3, this is due to the Dolby Surround signal that is matrixed intot the stereo stream

Quote:

. Is AC3 same as DS2 (Dolby Surround 2)?

Not at all.
Ac3 is a digital protocol to compress audio streams. DPL2 is a DSP (digital sound processing) operation done on a stereo stream in order to distribute the information on 5 speakers, even if the source wasn't DolbySurround !

rs008f · #16 02-26-2004, 12:35 PM

Is there a software that can tell if my AVI has Dolby Surround audio? Currently I have GSPOT and AVIcodec.

Dialhot · #17 02-26-2004, 12:48 PM

Only your ears and your brain can tell you that. You have to switch the DPL decoder of your receiver on and listen if what comes out from the back speakers is correct or not.

But you don't need to know that in fact as DS streams are stereo streams and are managed by all audio tools as it.

WHy did you ask that ?

rs008f · #18 02-26-2004, 12:57 PM

Because all my MPEG-4 AVIs have stereo audio and it's only worthwhile to convert it to AC3 if the stereo is Dolby Surround, so I need a software that can tell me that. I have a Dolby Surround Altec Lansing 3-speaker system (no back speakers, just 2 fronts and a subwoofer) on my PC, so i won't be able to tell if the sound is Dolby Surround or not. I don't have any speaker system on my TV.

Dialhot · #19 02-26-2004, 01:22 PM

So WHY do you want to convert it in AC3 ? I really don't understand your needs

Moreover there is somethbing that you missed in my post : if the audio is Dolby Surround, you will have audio on all the 5 speakers WHATEVER YOU ENCODED IT IN AC3 OR MP2 !
(changing from Mp2 to AC3 is just like changing the box arround a gift : it won't change the gift).

In other words: you do not need to encode in AC3 at all ! Mp2 is far enougth.

You should have a look on Dolby laboratories site if you want to understand all the systems that exist.

http://www.dolby.com/company/is.ot.0...erview.04.html

rs008f · #20 02-26-2004, 01:39 PM

OK now I get it. I at first thought that CCE won't transfer the Dolby signals to the encoded MP2 audio because a friend of mine uses AC3 format as his audio and I have been using CCE's encoded MP2 audio, he told me that his format is better but now I know there's no difference.