Converting lossless into what?

[pfc432]

Eventually my 80 GB hard disk has run out of space and, at least for the moment, I can't afford to get a bigger one. It has basically gotten overcrowded with audio files (which take up as much as 60 gigs).
I use my PC as the main device to play music (have no iPod), so the option of moving those files away from the computer or storing them in DVDs is at least very unpractical. As many of them are in lossless formats using way too much space, I've decided to recode them into a lossy format. The matter is, I cannot decide which one. And, as I'm not planning to keep the lossless originals, I don't want to choose carelessly. I want to avoid later having to recode them into another lossy format, incurring in grater data loss.

I am aiming for a bitrate of about 128-160 Kbps (could be higher, though) and would like to use some format newer than the good ol' MP3. I think the best options for this bitrate range are (in that order):
- Musepack
- AAC
- Ogg Vorbis

And I'd like to get your advice on which one to choose (and any other recommendations you deem important).

Apart from that I'd need to ask about the different AAC "flavors"? I read the wikipedia article, but it wasn't very clear there (for someone lacking any knowledge of audio codecs). In case I decide to use AAC, should I use something like the 'main profile' without any sort of extension (like HE-AAC)? Or is (e)AAC+ still preferable over the standard flavor?

Ah, one last thing: I don't care about things like the encoding/decoding time, as it'll be a one time thing, nor about the robustness of the format (error resilience); just about how my disk space will be used more efficiently.

Thanks in advance,

Pablo Fernández
<pfc432 atgmail .com>

[DewAsmara]

Hi Pablo,
After reading your long posting, I am not sure that AAC is your choice. Due AAC need a heavy CPU power especially if you want to play in home theater or something. But based on my personal experience, I have back up some sound into this part category:
1. MP3 at 320 kbps. (sample rate 48khz)
2. Dolby Digital AC3 at 640 kbps or 320 kbps. (sample 48khz)
3. MPEG4AAC at 256kbps (sample rate 44.1khz)

Sound below 192kbps sometimes not so clear in detail and not recommended as backup. Btw I used AC3 and AAC as sound for my movie. Never use as CD sound backup. Until now among those sound I am quite happy with AC3 Sound, much clear and better than those in MP3 or AAC.

[Blue_MiSfit]

Well, if you're main objective is to not have to re-encode to another lossy format in the future, then MP3 would be the way to go. It's totally universal, and I can't think of a single media player that doesn't support it.

Ogg Vorbis is my personal favorite, but hardly any hardware devices support it.

AAC is a great option, as long as your media player supports it. It's a safe replacement for MP3 at essentially any bitrate.

Seriosly though, recent builds of LAME can produce a really really good 192kbps VBR MP3, that is IMO indistinguishable from the original, even on good audio gear.

~MiSfit

[gameplaya15143]

128-160 KbpsMost audio codecs should sound decent at those rates. I would go with vorbis aotuv b5 in your case (q4 is about 128kbps, q5 is about 160kbps).

You should do some experiments, encode some songs to the different formats, and do a listening test for yourself.

[setarip_old]

@pfc432

Hi!the option of moving those files away from the computer or storing them in DVDs is at least very unpractical.Actually, unless your INDIVIDUAL audio files are greater than 4.37Gb each, storing them on DVDs (cost approximately 30 cents US each) would seem to be a very practical idea...

[pest]

Stick with AAC-LC. The extensions are only useful at bitrates < 80kbps. Nero has a free AAC encoder btw.
Unless you can't ABX lower bitrate AACs, stay with ~128kbps or ~192kbps for a good warm feeling.

[Calimari]

@pfc432
I store my music lossless on DVD in FLAC format. I store about 8 to 10 cd's on a dvd, depending on the playtime of course.
FLAC saves about half of the space of your uncompressed music.
Don't get rid of your lossless music, you never know which format you might need in the future (eg. I use MP3 VBR, but for my son's flash player I use WMA to save space).
MP3 VBR is a very good choise for playback. It's universal supported by hard and softwareplayers. The LAME encoder with --alt preset standard-- setting gives you excellent quality without having to go through a bunch of settings.

[chainring]

pest has nailed it dead on. Tests over at Hydrogen Audio have shown the modern codecs being transparent to many people at 128kbps. Those include: iTunes AAC, LAME mp3 and aoTuV; all being very close in performance.