HydrogenAudio

Lossy Audio Compression => AAC => AAC - General => Topic started by: ciber-fred on 2002-03-05 14:03:30

Title: psytel 2.15, just a question
Post by: ciber-fred on 2002-03-05 14:03:30
psytel encoder is a MPEG-4 encoder..

so why change the encoder to MPEG2 aac ???

on last version (1.6 for me) i can encode to mpeg4-aac main profile with the switch : -internet

now this switch create a mpeg2-aac file.. why ??

also in main profile the sound is clearly bad !!
Title: psytel 2.15, just a question
Post by: rjamorim on 2002-03-05 14:42:32
1 - You shouldn't use Main profile at all. It's buggy. Use LC instead.

2 - I believe it outputs MPEG2 AAC for reasons of hardware compatibility. The few players that play AAC (Expanium, as an example) play only MPEG2 AAC LC.

Regards;

Roberto.
Title: psytel 2.15, just a question
Post by: Ivan Dimkovic on 2002-03-05 14:59:16
MPEG-4 V1 (1999) Introduced these new features to the AAC:

- PNS Tool (Supported by PsyTEL AACEnc)
- LTP Prediction (Supported by PsyTEL AACEnc)

Also, there is a "scaleable" profile which is not implemented in psytel encoder, because I don't think it is useful much.

Note - these two tools are very new and as far as I know there is not a single commercial product that uses them (after three years the patent license for MPEG-4 AAC with LTP/PNS don't exist!)


MPEG-4 V2 (2000) Introduced these new features to AAC:

- Error Robustness (not useful in offline applications, like archivers)

- Low Delay AAC (I have developed this one, but it is also not very useful for general purpose)

- BSAC (bit sliced arithmetic coding)

...
Title: psytel 2.15, just a question
Post by: sven_Bent on 2002-03-06 07:19:22
Quote
PNS Tool (Supported by PsyTEL AACEnc) 
- LTP Prediction (Supported by PsyTEL AACEnc) 

Note - these two tools are very new and as far as I know there is not a single commercial product that uses them (after three years the patent license for MPEG-4 AAC with LTP/PNS don't exist!)



Hope that doesn mean that you, Ivan, are not thinking of using them sooner or later.

but as we have seen ivan is doing a hell of a job with his psytell encoder .when he things these tools can help (he figures out how to utilize them probaly) he wil probaly implant these....or what ??
Title: psytel 2.15, just a question
Post by: Ivan Dimkovic on 2002-03-06 07:47:44
LTP and PNS are implemented in psytel encoder, and they can be enabled and controlled, but they are not enabled by default .