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View Full Version : need help reencoding a he-aac (nd aac) stream to mp3

Sp00kyFox
24th February 2008, 01:11
i've tried it with megui but without "decoding via directshow" it gives me an error und with it gives me also an error except when I set ffdshow to decode aac-streams.. but then the result mp3 stream is too short (original lentgth 2 hours, result 21 minutes).

i've also tried to do it with virtualdubmod and besweet but it seems that both of them can't decode aac streams.
fibbingbear
24th February 2008, 01:20
Maybe I'm misunderstanding, but couldn't you extract the stream, use WinAMP to convert it to WAV, encode from WAV to MP3, and then mux it back in?

Don't forget there will be a quality loss when going from he-aac to mp3.
Sp00kyFox
24th February 2008, 01:38
I'm gonna try this but one question, is there a good reason to convert it first to wav and then to mp3 and not directly to mp3?
tebasuna51
24th February 2008, 02:54
i've tried it with megui but without "decoding via directshow" it gives me an error und with it gives me also an error except when I set ffdshow to decode aac-streams.. but then the result mp3 stream is too short (original lentgth 2 hours, result 21 minutes).

i've also tried to do it with virtualdubmod and besweet but it seems that both of them can't decode aac streams.

Yep, VirtualDub and BeSweet can't decode aac. And MeGUI don't know how can decode aac without directshow method.

You can use Foobar200 to convert aac directly to mp3, if the aac is multichannel you need some DSP function like foo_dsp_downmix.
Sp00kyFox
24th February 2008, 03:03
yeah thx, that worked.
Sp00kyFox
24th February 2008, 16:35
well no.. I thought so but with winamp the converted aac to wav file has only a left channel oO
I'm gonna try it with foobar.
Sp00kyFox
24th February 2008, 16:55
foobar gives me an "decoder produced garbage at 0:00.000" error right at the beginning of the converting.
tebasuna51
24th February 2008, 19:20
Seems your file is corrupted.
Sp00kyFox
25th February 2008, 02:39
well to me it seems that there isn't a simply way to reencode a nd aac stream.
fibbingbear
25th February 2008, 10:13
You could try db power amp, although it costs money to use it after the trial period if you're doing mp3 encoding.
tebasuna51
25th February 2008, 11:26
well to me it seems that there isn't a simply way to reencode a nd aac stream.

If 'nd' is NeroDigital you can use the methods exposed here:
- Foobar2000
- DirectShow methods with CoreAAC, ffdshow, ... using GraphEdit or AviSynth
- WinAmp
- Comand line methods: Faad, neroAacDec, ...

Other question is if a concrete file is corrupted.
Sp00kyFox
26th February 2008, 03:11
it seems that the file is corrupted else one of the mentioned suggestions would have worked, but thx anyway.. at least I know now how to reencode nd aac streams.
SpAwN_gUy
11th March 2008, 09:54
ok.. i guess... the AAC you have is demuxed from MKV-file..

remux AAC to mp4-File with mp4box ...

this might be due to.. mkvdemux produces.. some format (i forgot...) and for decoding you need some other timestamps or something...

and THEN reencode .mp4-file (you can rename it to .aac)...

currently, i'm trying to reEncode 6ch AAC... but so far.. no good... :( ...

bassAudio-plugin crashes on 6ch AAC
and FFmpegSource (FFAudioSource part) plays, but produces glitches :( ...

and i don't want to decode it to temp.. .flac.. or.. wav..