jHymn, quality degredation? Options

[VCSkier]

ive recently heard about this program called jhymn from a friend ( http://www.hymn-project.org/ ). apparently, it strips the drm from songs purchased from itunes. in the program, it gives options to convert .m4p or .m4b to .m4a, .m4b, or .mp3. now, obviously to convert to .mp3 would be lossy transcoding and would result in a loss of quality, but the jhymn site says that jhymn "allows you to free your iTunes Music Store purchases (protected AAC / .m4p) from their DRM restrictions with no loss of sound quality." can this statement be true? also, i have download both .m4p's and .m4b's from itunes (none of which will play in fb2k currently). to prevent quality loss, do i have to convert my locked .m4b to unprotected .m4b's, or is it ok to just convert them to .m4a's too? what are .m4b's anyways? the .m4b's i have are all just speaking (no music) and were offered for free (they are the presidential debates, in case you care).... anyways, what do you guys think?

[atici]

It's true. That's the whole point. It justs strips off the DRM -> no loss in quality. I don't know about m4b's.

This post has been edited by atici: Mar 7 2005, 08:00

[VCSkier]

hmmm, it appears fb2k dosen't recognize even my drm striped .m4b's. im shocked. ive never seen fb2k not handle something. im not pointing any fingers at fb2k though, what the heck are .m4b's anyway?! itunes garbage.... anyways, so it looks like im going to have to have jhymn convert even the .m4b's to .m4a's. now the question is still if that is going to cause me to lose quality. anyone know?

edit: grammar

edit: and spelling... lol

This post has been edited by VCSkier: Mar 7 2005, 08:56

[kjoonlee]

I'd guess M4Bs would be CELP-encoded speech in MPEG-4. (edit: No, they aren't!)

Converting them to MPEG-4 AAC will make the quality go down (AAC is lossy), but you might not notice.

This post has been edited by kjoonlee: Mar 7 2005, 17:12

[riggits]

hmmm, it appears fb2k dosen't recognize even my drm striped .m4b's.  im shocked.  ive never seen fb2k not handle something.  im not pointing any fingers at fb2k though, what the heck are .m4b's anyway?!  itunes garbage....  anyways, so it looks like im going to have to have jhymn convert even the .m4b's to .m4a's.  now the question is still if that is going to cause me to lose quality.  anyone know?

edit: grammar

edit: and spelling... lol

m4b is the AUDIOBOOK format. It's basically the same as MP4 or M4A except that iPods will track bookmarks. like, when u skip to a different book, ur place gets saved (either in the iTunes registry / database on the player, or in the MP4 tags) for future reference. Mighty handy feature when u wanna listen to a song after a few chapters of a good book.

edit: jhymn won't ever cause loss of quality, unless you consider DRM to enhance quality in some bizarre fashion. Audio quality is identical in stripped files, since decryption is a lossless process.

This post has been edited by riggits: Mar 7 2005, 09:07

[VCSkier]

hmmm, that is interesting riggits, and honestly, pretty smart... but so how can i get fb2k to play them? will i lose quality if i have jhymn convert them to .m4a, or is there a fb2k component i could use?

edit: sorry, didnt see your edit till after this reply

This post has been edited by VCSkier: Mar 7 2005, 09:15

[VCSkier]

except when you have jhymn convert to mp3, right? that would still have to degrade quality, wouldn't it? awsome though.... thats really cool, so im going to have jhymn convert all my itunes downloads to .m4a. thanks!

edit: clarification

This post has been edited by VCSkier: Mar 7 2005, 09:14

[kjoonlee]

Oops. Ignore my post above, please.

http://www.hydrogenaudio.org/forums/lofive...t19156-901.html

[kjoonlee]

m4b is the AUDIOBOOK format.  It's basically the same as MP4 or M4A except that iPods will track bookmarks.

Which means that DRM-free m4b files can be renamed to m4a without problems.

[VCSkier]

beautiful, absolutely beautiful. with the modified foo_input_std.dll that was on that page, fb2k can now play the .m4b's, so there's no need to even convert them to .m4a. thanks a million guys.

[VCSkier]

m4b is the AUDIOBOOK format.  It's basically the same as MP4 or M4A except that iPods will track bookmarks.

Which means that DRM-free m4b files can be renamed to m4a without problems.

if fb2k can play the .m4b's just as well, i might as well leave them as is, just on the off chance that i want to put them on an ipod and have the bookmarking feature. cool, very cool.

[Otto42]

Basically, iTunes will sell you M4P files or M4B files. Both of these have DRM.

jHymn will remove the DRM and convert it to an unprotected M4A file. If you leave the M4A named as an M4B, iTunes will continue to treat it like an audiobook file even though it's unprotected.

All conversions between M4X files are safe, they don't lose any quality. It's not actually doing any encoding there, just decryption and munging of the MPEG 4 wrapper. Converting to MP3 will be lossy, of course.

[blessingx]

Sorry to thread jack, but I was an Audible subscriber before the Audible/Apple deal, and my files (continue) to come across as .aa files. When I open them in iTunes info it shows as 32 kbps mono MP3 files. Could anyone tell me what the info states for the M4b files. Are they definitely AAC files? If so what's the bitrate?

[Otto42]

Sorry to thread jack, but I was an Audible subscriber before the Audible/Apple deal, and my files (continue) to come across as .aa files. When I open them in iTunes info it shows as 32 kbps mono MP3 files.  Could anyone tell me what the info states for the M4b files. Are they definitely AAC files? If so what's the bitrate?

They're definitely AAC files, and the bitrate I have seen is 32, although I think it varies depending on the particular book.

They have several free "books" available on the iTunes Music Store. Mostly political-related stuff. Grab one and see.