How Rip Audio file?

[magsoud]

I want Rip audio file (aac) without changing details.
Only Changing bitrate from 384kbps to 192kbps!
Please Help Me:thanks:
http://forum.doom9.org/attachment.php?attachmentid=13261&d=1360251790

[sneaker_ger]

There are a lot of programs that should be able to do that, like e.g. TAudioconverter (http://forum.doom9.org/showthread.php?t=165577).

But 192 kbit/s divided by 6 channels only leaves some 32 kbit/s, which is probably not transparent anymore - especially if you want to keep using LC. I wouldn't do it or at least consider downmixing to stereo.

[magsoud]

This is how?

qtaacenc.exe input.aac output.m4a --cbr 192 --samplerate keep --highest

[sneaker_ger]

1.) I'd rather recommend qaac instead of qtaacenc, because qaac is still actively developed and qtaacenc has bugs concerning channel mapping
2.) I do not recommend to use "cbr", because it is inefficient
3.) I don't think qtaacenc (and qaac for that matter) support direct aac input
4.) keeping the samplerate at this low bitrate for 5.1 channels might not be optimal

You can pipe:
ffmpeg -i input.aac -acodec pcm_f32le -f wav - | qaac --adts -a 192 -q 2 -i - -o output.aac
(If you need zero delay for a movie sound track, you can also add "--no-delay" to qaac's command line. If you need aac in m4a, drop the "--adts" and use the ".m4a" extension for the output file.)

I still think this bitrate might be too low for 5.1. I'd rather keep the bitrate or downmix to stereo and use an even lower bitrate. (like "-v 128" instead of "-a 192")

[magsoud]

@sneaker_ger :thanks: