HydrogenAudio

Lossy Audio Compression => AAC => AAC - Tech => Topic started by: petracci on 2002-01-09 09:16:38

Title: Psytel AAC vs. Liquid AAC?
Post by: petracci on 2002-01-09 09:16:38
Any thoughts (quality, EoU, differences) on the comparison between the Psytel AAC encoder and the (reference) Liquid Audio encoder? Pro's & con's would be appreciated..

Cheerz,

Petracci
Title: Psytel AAC vs. Liquid AAC?
Post by: Ivan Dimkovic on 2002-01-09 11:15:21
Well.. as a one and only developer of PsyTEL AAC encoder I could give some hints..

at the early stages of development we all thought it was impossible to 'match' FhG AAC quality  However, latest versions of PsyTEL AAC are very close to FhG at 128 and 96 kbps bit rates, and even better for some VBR presets.

FhG still has edge at 32 kHz / 64 kbps, and lower bit rates because AACEnc is not tuned completely for these bitrates yet, but this is being carried out right now

I think that using of LiquidAudio has very little advantages, except if you are encoding at ultra low bitrates. First of all, this is a 'ware' software, it is not adhering the ISO standard (it has proprietary wrapper) and it is not possible to play files on other OSes.
Title: Psytel AAC vs. Liquid AAC?
Post by: petracci on 2002-01-09 11:32:38
Thanx for the reply...

Could you give some more detail (e.g. artifacts) about the 'edge' at low bit rates?
Do you know if LA also has MPEG4-AAC implemented, including TNS? I understood from a post on this forum that TNS is (one of the) difference between MPEG2-AAC and MPEG4-AAC...

Keep up the good work...

Petracci
Title: Psytel AAC vs. Liquid AAC?
Post by: Ivan Dimkovic on 2002-01-09 11:39:08
Well, files encoded with FhG AAC at very low bitrate are distorted, but sound more 'smooth' or pleasing to the ear, thanks to the additional codec tune-up for low bitrates. This will be done in PsyTEL AACEnc, too.

For example, velvet.wav will have distortion, but more like mid-frequency 'flanging' - other encoders will have more obvious distortion like chirping, etc..


TNS is used in MPEG-2 AAC and MPEG-4 AAC. MPEG-4 AAC has other tools (LTP prediction, PNS - perceptual noise substitition, etc..)

Visit www.aac-audio.com (http://www.aac-audio.com) for technical information regarding AAC.
Title: Psytel AAC vs. Liquid AAC?
Post by: petracci on 2002-01-09 12:04:14
Rightie...

For a comparison (speech & music) of codecs around 32/64 kbps, which codecs would you think of interest?