Converting AAC+

[exwintech]

A Search here for things related to AAC+ brought up plenty for "AAC", but nothing for "AAC+" - as in, AACplus.

This flavour of AAC is used by some Internet radio stations - and also by Australia's thrice-accursed digital DAB+ radio. As AAC+ maxes out at 64kbps as a low bitrate format - above that std AAC is considerably better - it's not the best of things. However, once one has AAC+ files, it'd be nice to be able to do something with them.

If actually downloading from Internet, Gnome Recorder will convert AAC+ to WAV, OGG, MP3, and more.

What I can't find, is a Linux app that will convert AAC+ files - if folk ask me, Can you do anything with these?

Any ideas? Even something free that has to run in Wine would be better than nothing....

Any workable solution would be much appreciated, thanks.

Regards, Dave.

[daniel]

Which programs plays ACC+ by you?

[Just17]

Will PACPL not convert those files?

I don't have a sample file to check unfortunately .....

[exwintech]

Leiche - That's just it - nothing I can find either converts or plays it, other than as a stream from Internet. If, say, VLC, could play it - it might be able to re-record it as something else - preferably Flac or WAV, lossless.

Gnome Recorder 2.32.0, as in PCLOS Repos, is an excellent and very well-behaved device, and when the AAC+ on a site is run via browser, it will record the stream AND convert it to Flac, WAV, Ogg, MP3, etc. Also what it calls "AAC - M4A type". WAV and Ogg work very well - but Audacity and SoundKonverter won't touch the version of Flac it converts the AAC+ to.

If the "AAC - M4A type" is selected and downloaded - as with other AAC+ files I have - nothing I can find will play or convert it.

However - if the source recorded from is "Std AAC" - and the record-mode is "AAC - M4A type" - that plays or converts in the devices that usually handle standard AAC - example - AAC audio stripped out of a video from that tubular-type place.

Apparently one of the reasons our Oz Great Leaders (?) - chose DAB+, not the usual-overseas standard DAB - is that it transmits in 64kbps AAC+ - and should the "disobedient peasants" dare record it - they'll find it very difficult to do anything with. I don't have a DAB+ radio - but have had a few files recorded from one - and no - I can't do anything with them - either!

From Googling-around - it seems that at and above 64kbps, standard AAC is good audio, below that it isn't. So folk invented High Efficiency AAC - HE-AAC - also called AAC+ - which is quite reasonable broadcast / streaming quality at 48-64kbps. Allegedly equal at 64kbps to MP3 at 128kbps, though folk on audio forums say, actually similar to MP3 at 96kbps. And notably inferior to FM, either for broadcast listening or recording.

Just18 - I haven't tried the Perl converter for AAC+ - thanks for the heads-up on that - shall get it, soonest! As for samples - I run the online AAC+ station with Firefox - and use Gnome Recorder in one of its modes to record. This system is running PulseAudio - I don't know if Recorder does that - or "all the formats" without. However, I can record the AAC+ with Recorder's "AAC - M4A type" mode - and obtain files that none of my present apps or tools will touch... Shall see if the Perl device does - and blessings be upon you, if it does...!

Regards, Dave.

[exwintech]

Just18 - I see now that the Perl Converter is CLI - so I might be doing that wrongly. So could you please advise how to enter the command correctly? Here's my third attempt:

[david@localhost ~]$ pacpl --to mp3 /home/david/Desktop/CathysAACplus.m4a
Perl Audio Converter - 4.0.5

Converting:  [CathysAACplus.m4a] -> [mp3] INFILE: /home/david/Desktop/CathysAACplus.m4a
encode failed with exit status: 256

Total files converted: 0, failed: 1
[david@localhost ~]$

- It looks as if it was trying to run the conversion - maybe it needs more definitions in the command? Is the '256' a hint at that?

Regards, Dave.

[Just17]

PACPL is a context menu  ........  right click on file in Dolphin - Actions - PACPL Convert .......  and I hope you have a tall Monitor to see all the options  

EDIT:
           I generated an AAC (ordinary I suppose) file from an MP3 using PACPL and right click .... Play .....  all good for that part.

Maybe PM me a link to grab an AAC+ file ....... ?

EDIT2:
                libfaad2 is reported to decode AAC+ files

if you need decoder, use lib faad2

http://tipok.org.ua/node/17

[daniel]

Try

mplayer name_of_your_file

and

Code: [Select]

mediainfo name_of_your_file
Make sure, you have installed mplayer, and mediainfo.

Please post output, thanks...

[Just17]

OK, after some investigation, it seems that the present packages in PCLOS cannot handle AAC+ at 64K bit.

I found a radio stream at 64K bit and played a bit with it.

I could listen to it via VLC, and record as I was listening.
The recorded result was a 48K bit AAC+ file.

Using the same stream, I played it through Radiotray and other stream players; recorded it with gnome-recorder.
None of the players on my PC could play it or do anything with it. Maybe gnome-recorder failed to record it properly to .m4a .....

It appears that updates to such as ffmpeg, and VLC may be needed to handle such files.

I am not sure how current this page is .....
http://tipok.org.ua/node/24

Having said all of that ........  I may be misinterpreting the results I am getting ........  could someone else do some tests to see what they find?

In case you were wondering what AAC+ does, its’ the following: a spectral analysis is done. The lower half of the spectrum is encoded along with hints to reconstruct the higher half based on the lower half (this is called Spectral Band Replication, SBR, and forms HE-AAC v1). For low bit rates, mono audio is encoded with hints to reconstruct stereo (this is called Parametric Stereo, PS, and forms HE-AAC v2).

http://tech.poojanblog.com/blog/unix-linux/setting-up-aacplusenc-with-ampache/

[djohnston]

exwintech,

See if this online converter site will yield any acceptable results.

[marian]

Any ideas? Even something free that has to run in Wine would be better than nothing....

What about AudioCoder. You can run it in Wine.
http://www.mediacoderhq.com/audio/

[Just17]

Has anyone checked their PCLOS install to see if it can handle 64K bit AAC+ (HE-AAC V2) files?

I am still unable to manage them without the result dropping to 48K bit.

Gnome-recorder seems to have a problem converting to .mp4a ......  resulting files are unusable it seems.

[demilord]

soundkonverter?

[Just17]

soundkonverter?

It does not handle 64k bit AAC+ files here ........  will it do so on your install?

[demilord]

it uses ffmpeg so i think it should.... can uses multiple backends...

[Just17]

it uses ffmpeg so i think it should.... can uses multiple backends...

I would be interested in your results from some test .......  all I can get stored is a 48K bit file and not the 64 bit from the stream.

Is that a definite limitation of my install or does the same happen for others?

Only way to know is some test results ...