AAC 5.1 Conversion

[zammil]

Hi friends,

I'm not very familiar with audio tools so can anyone suggest any software for converting AAC 5.1 l to other formats with minimal quality loss.is it possible to have the sound file to be converted to parrticular size like two pass encoding in video.

Thanks in advance

[hech54]

You are not familiar with the rules either are you? Stop double posting.

[zammil]

sorry hech54 !!i didn't do it intentionally.i was trying to upload a sample.and i don't know what happened.I'm really sorry.

[guns1inger]

Don't know if you can load AAC 5.1 into the latest Beta Audacity once you have the ffmpeg libraries installed, but if so, you can then convert and output to a variety of formats. Only some formats will allow you to keep the 5.1 channels though.

As for size, just like video it all comes down to bitrate. You will only get a single pass encode though - I don't know of any multi-pass uudio encoders.

[zammil]

audacity is opening it as a mp3 file.any other audio softwares

[hech54]

BeSweet can convert 5.1 to "six waves".

[kurian]

i'm also having problems converting aac files.goldwave,reaper none of them recognizing it .here is a sample of it

[hech54]

You're right....BeSweet isn't recognizing it.
But SUPER did.

[kurian]

yes Super do work.but i don't want any quality loss.is there any kind of lossless conversion setting in super

[hech54]

yes Super do work.but i don't want any quality loss.is there any kind of lossless conversion setting in super

AAC and AC3 are already compressed to hell and back....going to WAV will not improve the quality. AAC and AC3 are the video equivalent of MP3 for music. How exactly are you going to gauge the loss of quality from your file to the "next" format? File size certainly isn't going to work.

[zammil]

thank you guys super is able to input it but I'm getting the following error when encoding it.moreover i cannot specify the o/p size.got any other softwares

[hech54]

If the sample you provided me doesn't work with SUPER....then you need to follow it's instructions and check DirectShow. SUPER is very good at having built-in workarounds to get the job done.
The only way to change the output size is to raise or lower the bitrate....but again like I said before...raising the bitrate is NOT (I repeat...NOT) going to improve the quality. Lowering the bitrate decreases quality...raising the bitrate does NOT improve the quality. At best it MIGHT retain the original quality of the original AAC file....MIGHT. Those are your only options. Retain as much as possible...or further decrease the quality.

[kurian]

ok hech54 i will go with increasing bit-rate .but super allows to choose b/w only 14 bit-rates.what if i want other bit-rates for my audio files so is super the ultimate audio converting tool or is there any other tool with more options

[hech54]

From multi-channel AAC.....SUPER is the only one I'm familiar with. I have no multi-channel audio in my house so my knowledge of encoders and editors on that stuff is limited.
Don't forget....you can probably go to 6 individual WAV files as well. Theoretically that should be an almost exact copy of what you have depending on how good SUPER's decoder is. I've created several 6 channel waves from AC3 5.1 in my day(genuine 5.1...recorded in 5.1) to remix songs(more prominent vocals, less bass....whatever) using the same method and later remixing in Reaper.

[Case]

choose b/w only 14 bit-rates.

The valid bitrate values for AC3 are: {32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 448, 512, 576, 640}. Note that the DVD specification has an upper limit for AC3 audio at 448 kbps, which is used for many 6 channel encodings on commercial DVDs.

[zammil]

another query hech54 hope u don't mind.can i convert aac 5.1 to 2 channels without quality loss. will it result in low o/p sizes

[hech54]

I've never mixed down all 5.1 channels to 2.0. I've always picked left, right and whatever channel had lead vocals on it and just used 3 of the 5.1 to create my remixes.
Of course you can go smaller output file size....but just remember you already have the equivalent of MP3 files now with your AAC files. They are already compressed from an original source(most likely LPCM). If you intend on using these new output files in video then you need to follow more rules as to what audio is allowed with what video(MPEG2 for DVD, MP3 for Xvid/Divx, etc etc etc.) If these files are for your person listening pleasure in an iPod or similar device....well....you still haven't said what you intend to do with these new output files.

[zammil]

i just want it to play it on my PC(maybe sometimes on DVD ) .so keeping down to 2 channels better with added advantage of low size if no quality is losed.can it be done ???

[yoda313]

If you want to mainly play it on your pc why are you converting it all? You should be able to playback aac 5.1 with a program like media player classic home cinema or vlc.

Have you tried the original file that way?

If you intend to play it on a normal dvd player as a real dvd than yes you will need to convert to ac3 or wav. But if you just want to play the file on the computer leave it as it is

Edit - also audio file size should not be a factor. How much free space do you have? If you are that crunched for space you might be better off investing an extra harddrive rather than wasting time and losing quality with needless conversions if the pc is the main playback device.

[kurian]

reaper can convert it to 2 channels