m4a 2 mp3?

[Chris Benoit]

I have some m4a and want to convert them to mp3.Which tool shall i use,and do you think the loss qualiy will be noticeable?

[SeeMoreDigital]

Provided your M4A files contain 2Ch AAC-LC audio, the newer versions of Apples iTunes can do what you require. As can Foobar2000 and dBpowerAMP....


Cheers

[Chris Benoit]

I tried foobar but i get excessive file sizes.Yes there are lc 2ch mp4 and i want to make them mp3 for compatibillity reasons.

I tried --alt-preset standard and i got 7,5mb and --alt-preset cbr 80 and got 4,5.

The source is 65kbps and is 3,2mb.

How can i get a filesize that low?

[foxyshadis]

AAC is more compact than mp3, you'll always suffer a significant quality loss if you use the same bitrate, but that's your choice. If you want the same bitrate, use -abr 65. (APS is tuned for ~170-190 kbps, and likely won't do anything but increase encoding time at that low a bitrate.)

If you have any choice in using a more modern format, I'd think about doing that.

(Edit: AAC not AC3, duh, though it was still true.)

[Sharktooth]

I tried foobar but i get excessive file sizes.Yes there are lc 2ch mp4 and i want to make them mp3 for compatibillity reasons.

I tried --alt-preset standard and i got 7,5mb and --alt-preset cbr 80 and got 4,5.

The source is 65kbps and is 3,2mb.

How can i get a filesize that low?
AAC is more efficient than mp3. you cant get a mp3 with the same quality at the that bitrate...

[Chris Benoit]

Yes i know that guys but as i've said i'm doing it for compatibillity reasons.

I downloaded some m4a audio and want to play it on the PSP which only supports Attrac3+ and mp3.

Since Attrac3 is not worthy (or is it?) i have to go with mp3...

[SeeMoreDigital]

Yes i know that guys but as i've said i'm doing it for compatibillity reasons.

I downloaded some m4a audio and want to play it on the PSP which only supports Attrac3+ and mp3.

Since Attrac3 is not worthy (or is it?) i have to go with mp3...Eh!

The PSP has got to support AAC audio..... Try re-naming the .M4A extention to .MP4.... so the PSP thinks it's an combined video+audio file!


Cheers

[Chris Benoit]

i've already done that but it didn't work.Version 2 and higher have aac support,since i'm on 1.5 in order to run homebrew i'm stuck with no aac!

As for the conversion,using commandline in foobar i can't get lower than 80.It displays some errors,and on the other hand razorlame doesn't support,m4a,mpa or aac whatsoever.What other options do i have?

BTW y did you change your house avatar,it looked kewl!

[foxyshadis]

Oh yeah, I forgot to mention, mp3 is picky when it comes to bitrates. Higher sample rates can't go below some bitrates, and lower ones can't go above certain ones. Everything is supported at 32, if you like that underwater vibe. =D (Stereo also affects it but I presume you'd rather not switch to mono.) Resampling to 22 won't loose too much fidelity, and will definitely sound better at hella low bitrates.

If you want to use razorlame, it'd be easiest to extract to wav with foobar/winamp/besweet first.

Yeah, SeeMore, you confused me too =p

[SeeMoreDigital]

Okay.... Dr. Gregory House is back... by popular demand :D

Chris... what happens if you mux a bit of video (or a still image) together with your AAC stream, into your MP4?


Cheers

[Chris Benoit]

I haven't tried to mux a still image i just renamed to mp4 and didn't work,i'll try that then.How can you mux an image that will be displayed till the end of the track?

As for foobar i tried 32 and 22 and still didn't work.I encoded to wav (PCM fixed point) and then when i try to encode with razorlame i get a "133 error"

[bond]

moved to audio coding