AAC or Vorbis (64kbps) for low quality movie copy?

[Turneliusz]

I'm making low quality movie copy and i have a problem. What audio codec to use (for bitrate around 64kbps)? In this movie there is a lot of dialogs and music appear rarely.

Of course, there is a listening test but it was made from music samples.

[check]

Definately AAC. I would encode with Neroaacenc. q0.25 comes out around 64kbits for audio files, or you can just use 2pass average bitrate mode.

[gameplaya15143]

Definately AAC.
I'll disagree with that :)

Plenty of quality soundtrack ~64kbps:
oggenc -q 0 --advanced-encode-option lowpass_frequency=99
(depending on your taste, adjust the lowpass as desired)

High quality ~96kbps:
oggenc -q 2 --advanced-encode-option lowpass_frequency=99

Good enough ~48kbps:
oggenc -q -.5 --resample 37800 --advanced-encode-option lowpass_frequency=99

This assumes you are using stereo. For me, 48kbps and higher, I use vorbis.

The only way for anyone to decide, is to try both, and pick the one that you prefer.

Disclaimer: it's my opionion ;)

[buzzqw]

@gameplaya15143

i share your opinion too

Vorbis can beat many audio codec if kbps is over 64k and IF correctly tuned (and if based on aoTuV)

anyway is alway better to encode with both codec and let's hear judge the quality

BHH

[Eretria-chan]

HE-AAC @ 48 kbps sounds good enough to me. The lower the bitrate, the better. For space, that is.

[Sharktooth]

Uhm... i usually use HEv2 (AAC+) for 48kbps, vorbis for 64 and higher bitrates, but it depends also if i want the final file to be mkv or mp4.

[shon3i]

Uhm... i usually use HEv2 (AAC+) for 48kbps, vorbis for 64 and higher bitrates, but it depends also if i want the final file to be mkv or mp4.
of course, but vorbis without tweaking lowpass frequency and resamping sonds like metal. For me HE-AAC sounds very good for low bitrates 32(PS),48-96kbps newermind CT, Nero, but i think wma 10 sounds little better, but is not supported by any type of conteiner unless wma,wmw, my recommendation if you'r video is ASP/AVC, than for audio use AAC (quality and compactibily reasons) and you have to containers, MKV and MP4

[Kurth]

AAC+SBR 64kbps is better than Vorbis 64 kbps.

For low bitrate I like to use AAC+SBR 40 kbps Stereo not PS.
http://img155.imageshack.us/img155/5306/40kbps5kr.jpg <<-- Encode config.
http://img153.imageshack.us/img153/7202/quality8vu.jpg <<-- AAC+SBR 40 kbps Stereo.

[shon3i]

40kbs without PS, hmm

[bond]

i dont think that lc-aac beats vorbis at 64kbps (but thats just quessing!!!), he-aac is propably on par or better than vorbis

[DeathTheSheep]

I'll agree with bond all the way man.

But you've gotta admit, the Nero CLI with the -lc tag at quality .15 gives you from 50-64kbps LC-AAC...which sounds great. A bit tinny at times, a bit of ringing, but the lowpass is pretty high and the sounds for the most part crisp and clear enough for me. Especially if MP4's the container o' choice. ;)

[Sagittaire]

At this time impossible to say if AAC is always better than Vorbis simply because there are no public test to demonstrate that.

Moreover IMO and only IMO AAC+ V1 is by far better than Vorbis at 64 Kbps and lower bitrate.

[shon3i]

AAC+ V1AAC+ V2 can't be used for that bitrate, only for <=48kbps, and LC-AAC is not good for low bitrates <=96kbps

[Kurtnoise]

@shon3i : read carefully Sagit's reply...AAC+ v1 = HE-AAC. He doesn't speak about AAC+ v2.

And regarding strictly the specs, there are no lower/higher limits for PS/HE/LC bitrates values. But AAC encoders supplying these modes are more efficient according to some target bitrates...

[Sagittaire]

AAC+ V2 can't be used for that bitrate, only for <=48kbps, and LC-AAC is not good for low bitrates <=96kbps

and be carefull bitrate for audio quality don't mean anything like for video codec. Compressibility for movie audio stream are generaly always very lower than for pure musical CD source. Lame -V5 will done ~128 Kbps for very large overall music source but perhaps more like ~100 Kbps for movie audio stream. IMO LC-AAC 2.0 at ~80 Kbps for movie audio stream will done certainely very good quality for general case. HE-AAC 5.1 at ~128 Kbps for movie audio stream will done too excellent quality in general case.

[xyloy]

For me:
CT's(winamp 5.24's .dlls given with MediaCoder 0.3.9) HE-AAC v2(=SBR+PS) at 48 kbps and lower(I use it for movies).
CT's(winamp 5.24) HE-AAC v1(=SBR) at 80 kbps and lower(never used it for now).
CT's(winamp 5.24) LC-AAC(no SBR, no PS) at 96 kbps and higher(for audio CDs).

edit: Kbps values modified. (thanks to Sagittaire)

[Sagittaire]

128 Kbps HE-AAC 2.0 ... ???

Not good idea because SBR become useless for bitrate higher than 80-96 Kbps. PS is really usefull only for less than 48 Kbps and it's for Music here (low compressibility source)

[xyloy]

It was a wild guess anyway. :D

[shon3i]

read carefully Sagit's reply...AAC+ v1 = HE-AAC. He doesn't speak about AAC+ v2.


Sorry Sagittaire my mistake, i don't see whole post...

128 Kbps HE-AAC 2.0 ... ???Why did you see some artifacts, i know that sbr is not so good but AAC have switcher like for Joint Stereo, then ge use SBR where need. Aslo CT have High SBR encoder aka Downsamled SBR (88.2khz), Nero don't use this feature, but anybody newer proved that SBR/DSBR(88.2) can help in High bitrates, so my ears can't find differents. Aslo HE-AAC @ 128 is good for 6CH encoding