HydrogenAudio

Lossless Audio Compression => Lossless / Other Codecs => Topic started by: geeuhnfay on 2012-06-07 02:37:42

Title: Dbpoweramp ALAC and iTunes ALAC
Post by: geeuhnfay on 2012-06-07 02:37:42
I know that lossless to lossless encoding has no degradation since it's just compression algorithms but I'm wondering since the dbpoweramp ALAC codec was reverse engineered from the iTunes one.

I'm ripping to FLAC using dbpoweramp and then converting it to ALAC so that it's compatible with iTunes. From here I convert the dbpoweramp ALAC to iTunes ALAC encoder. Is this OK or should I be using AIFF as the intermediary format.

I would just rip with iTunes but I like accurate with dbpoweramp
Title: Dbpoweramp ALAC and iTunes ALAC
Post by: greynol on 2012-06-07 02:53:48
Why not just rip directly (for all intents and purposes) to ALAC using dBpoweramp?
Title: Dbpoweramp ALAC and iTunes ALAC
Post by: geeuhnfay on 2012-06-07 03:05:29
"Using the dBpoweramp ALAC encoder as an intermediary format should be perfectly fine. In that case the dBpoweramp ALAC encoding is short lived and serves a useful purpose.

My concern with using the dBpoweramp ALAC encoder would be for using it as your primary format long term or for archival storage. I wouldn't trust it long term and especially for archival storage. Everything was reverse engineered. You have to trust that they got it all right. If they did something just slightly different or slightly incorrect a future version of iTunes or some other tool in the future could corrupt the files. I just don't trust it. Apple isn't going to run compatibility tests against dBpoweramps ALAC implementation when doing QA on future versions of iTunes and ALAC. Third party tools that support ALAC are going to test against Apple's ALAC implementation and may completely ignore testing against dBpoweramp's ALAC implementation. (I do software QA, I don't have a lot of trust non-conforming software to continue to work or remain compatible)

In your case the dBpoweramp ALAC file is short lived. It soon gets converted to the iTunes ALAC format and is all good."

This is what somebody posted at headfi and I just want to make sure.
Title: Dbpoweramp ALAC and iTunes ALAC
Post by: odious malefactor on 2012-06-07 04:25:39
Spoon (author of dbpoweramp) wouldn't need to "reverse engineer" ALAC, as it's an open source codec.
Title: Dbpoweramp ALAC and iTunes ALAC
Post by: garym on 2012-06-07 04:38:23
Spoon (author of dbpoweramp) wouldn't need to "reverse engineer" ALAC, as it's an open source codec.


It is now, and my understanding is that dbpa now uses the official codec.
Title: Dbpoweramp ALAC and iTunes ALAC
Post by: db1989 on 2012-06-07 16:28:12
I think the OP is asking whether reverse-engineered implementation(s) of ALAC are indeed lossless; I’m sure they are, despite their unofficial nature. Anyway, now that ALAC is open-sourced, as has been said, there’s even less need to be concerned.

I convert the dbpoweramp ALAC to iTunes ALAC encoder. Is this OK or should I be using AIFF as the intermediary format.
If I had a penny… All formats must be decoded to PCM (here, read that as AIFF) in order to be converted to another, lossless or otherwise; it’s just that some hide the process from the user rather than spitting out a WAV file and possibly requiring them to manually perform the next step.