Demuxing/Converting from AAC

[zilog jones]

I have an MKV video, with an audio track, but I'm not sure exactly what it is. Media Player Classic says it's "5.1 HE-AAC", and VirtualDubMod says it's "A_AAC/MPEG4/LC/SBR".

Basically, I want to de-mux it so I can apply a NTSC-to-PAL (23.97 to 25fps) conversion for output to DVD video. I don't mind if it's 5.1 AC3 or just stereo MP2. I've used BeSweet for this kind of stuff before, but I don't have a clue about how to handle Matroska files or AAC...

I've tried demuxing it through VDubMod, but I don't know what extension to give the file (if there is a suitable one?) - I've tried aac and mp4 but got nothing readable from it.

Please help me!

[zilog jones]

OK, I got the AAC file demuxed at least, thanks to MKVtoolnix and MKVextractGUI. It's playable too! But I'm still lost as to how convert this thing! I'd like to convert it to wav so I can pass it through BeSweet to change the speed (NTSC-to-PAL), but what should I use for that?

I tried dBpowerAmp with the M4A/AAC input plugin, but it just crashes just after creating the wav files and keeps making files about 60 bytes in size. Anything else I can try?

[bond]

Originally posted by zilog jones
[B]OK, I got the AAC file demuxed at least, thanks to MKVtoolnix and MKVextractGUI. It's playable too! But I'm still lost as to how convert this thing! I'd like to convert it to wav so I can pass it through BeSweet to change the speed (NTSC-to-PAL), but what should I use for that? use faad2 to decode the he-aac to .wav, you can get it here:
http://www.rarewares.org/aac.html

[zilog jones]

Yeah, I eventually found that last night. But it seems BeSweet doesn't seem to like 5.1 wav files - it says "Error 58: Error : Unknown Input-File Format".

I would prefer to keep it 5.1, but how can I make it readable by BeSweet, or is there something else I can use for making AC3 audio that would work better?

[bond]

Originally posted by zilog jones
I would prefer to keep it 5.1, but how can I make it readable by BeSweet, or is there something else I can use for making AC3 audio that would work better? [/B] use the original ac3 from your dvd source

[zilog jones]

I wouldn't be doing this if I had a DVD source! It's a fansub.

[MadlyMad]

Hi

I'm somehow in the same situation
I have a 5.1 aac LC file, and I would like to convert it from 25,000 (PAL) to 23,976 FPS (NTSC)

what is the best tool to handle thoses kind of file ?
unfortunately besweet can convert To aac but can't convert FROM aac :(:(
cause I would prefer not to convert it in 5.1 wav if it's possible
and I would prefer it to stay aac (not ac3, just a matter of size)

btw, I saw you can have bug using this or that tool to mux MKV, which is the best one too ? including an option to delay the audio track cause I believe when I'll done the first step there will still be a constant delay to apply =)

thanks

[MadlyMad]

no ?
nobody ?? :confused:

[Sharktooth]

why not change the video FPS to 25 instead?

[MadlyMad]

'cause it's not the aim =)

and I don't want to lose some video quality (or even having a bigger file for nothing)
and, plus, I'll have to transcode another audio track to fit this so....
:cool:

[Sharktooth]

you wont loose anything converting the FPS...

[MadlyMad]

true
forgot we could change the FPS in direct stream copy mode

but anyway, I still have to do this And convert the other track too

this is still a solution yeah, but I would prefer learn which software can handle/edit 5.1 aac file to convert it directly from PAL to NTSC

[tebasuna51]

this is still a solution yeah, but I would prefer learn which software can handle/edit 5.1 aac file to convert it directly from PAL to NTSC

To do this you always need decode to uncompresed format, timestretch, and reencode to aac one more time.

I don´t know if Foobar have any DSP timestretch function, then, if you don't want intermediate wav files, you need use AviSynth methods (BeHappy, SoundOut or Wavi).