HydrogenAudio

Lossless Audio Compression => WavPack => Topic started by: BearcatSandor on 2010-05-19 07:30:20

Title: setting up a collection of monolithic wavpack files with tags?
Post by: BearcatSandor on 2010-05-19 07:30:20
First off, i'm using Gentoo Linux.

I have a collection of about 14k tracks ripped from CDs (that is if i can recover a hard drive gone bad, but that's another story) processed into individual flac files.  I have lots of hours put into tagging especially comments (lead singer, disc type etc) and cover scans etc.

If i can recover this drive i want to re-do the collection.  I'm interested in wavpack, as i've read many good things about it and i think it might meet my needs. Here's what i want to end up with:

1. All albums are a single file.
2. each file contains the album artist, year, genre. Individual tracks within the monolithic track contain the track number, track artist, performer and comment.
3. each file contains full covers (front, back, cd, liner notes 1, liner notes 2 ....etc)

What i'm not sure of is how to handle the "tags". I've been looking around the forums and it seems that the way to do this is with an embedded cue file. I've looked a few cue files over and i don't see where one would insert the comment tag but i'd swear i've read of it being done.

I'm going to be writing a bash script to convert/process all this automatically. I don't really need guidance with that but i'm wondering if this set up is feasible before i plunge in.

Will most media players read such a monolithic file and display the cover, and track information correctly during playback (i.e MPD, mplayer, etc)?

I am under the impression that wavpack will handle this better than flac.

Thanks

Bearcat
Title: setting up a collection of monolithic wavpack files with tags?
Post by: bryant on 2010-05-20 08:00:30
I have never seen a per-track COMMENT tag in a cuesheet, although I can see how that would be useful. It might have to be entered as a REM to avoid breaking some cuesheet parsers, and probably no programs would properly show that information (although if anyone else knows differently I am happy to hear about it). BTW, being able to handle embedded cuesheets at all is by no means universal in players, even those that do handle WavPack.

A bigger concern for me with what you describe is embedding all the artwork into the single file. WavPack allows up to 1 MB of APEv2 tag data, which is certainly enough for reasonably high-res front and back cover scans (for instance), but it you want readable liner booklets then this would probably not be enough. I have thought about increasing this (at least in some circumstances), but the idea of this data is to be compatible with embedded and streaming situations...it’s not really intended to hold 20 MB of scans!

There really isn’t a well-defined, universally accepted (and easily playable) method of storing complete albums in a single file like you want. A WavPack file like you describe might fulfill some of the requirement (with a few caveats). A Matroska file is another option, but I’m not sure there are too many playing options. Another idea I have seen lately (and have played around with a little) is popular in Russia and involves putting a WavPack file (with an embedded cuesheet) into an iso image file (with all the extra artwork) and giving it the extension .iso.wv. This is a little weird because it isn’t really a WavPack file at all, but because of the way the WavPack library works many players can access the audio just fine (as long as the WavPack file is the first file in the iso). Something like this could also be done with a zip container (assuming compression was turned off). This is discussed in detail in this thread (http://www.hydrogenaudio.org/forums/index.php?showtopic=79456).

Sorry there’s no easy answer here... 
Title: setting up a collection of monolithic wavpack files with tags?
Post by: BearcatSandor on 2010-05-21 04:31:00
Thanks for the reply Bryant. I'm kinda surprised actually. I thought there would be a way to do this (at least the tags) as keeping your albums as one file seems quite common. I assume that a cue sheet would be the only way to accomplish this?
Title: setting up a collection of monolithic wavpack files with tags?
Post by: Fandango on 2010-05-21 10:54:20
You could adopt foobar2000's way of storing per-track tags in a single album image:

"CUE_TRACK"+$tracknumber+"_"+$tagfield

So for example: CUE_TRACK01_TITLE

$tracknumber is always padded with a zero upto two digits, i.e. the first 9 tracks are padded.

But be aware that this is not a standard, foobar2000 is the only application that does it this way. It's needless to say that the most convenient way to edit the tags of such an album package is to use foobar2000 itself, it does everything transparently and you won't have to worry about the correct tag field names.

You are mentioning Unix programs, so I assume you don't use Windows for media playback. While you can use foobar2000 using Wine, you might not want to. Support for image rips was really bad a few years ago for non-Windows players, but it has improved a lot recently. But you might end up using a player not because you like its overall features, but because you have to because of its image rip support.

Well, good luck with your project. You will have to invest a lot of time and thought into it, and there are certain things that simply cannot be done. Also I'm pretty stuck with foobar2000 with these rips, which isn't a problem for me, but it's still not a good feeling to know that this might become an issue in a few years. So I gave up creating single image rips for these reasons, they are much harder to manage than per-track audio file rips. Though I'm not converting the existing image rips... not yet.

The main realization that tipped over my concerns with per-track files was that for playback on a PC (and actually on a CD player, too) the pre-gap information in the cue sheet, and hence the cue sheet itself is not needed. It has no impact on the listening experience. Also the pre-gap information isn't reliable in the first place, it depends on the ripper, drive model and CD what pre-gaps you get or if you get them at all. So I came to the conclusion that all this is heavily overrated, although it took me a while. Also I have absolutely no need to store everything in a single archive, but I realize that there are certain P2P-clients that are single-file-based rather than multi-file-based and that this might be the driving force for many people to embed everything into one piece.

As Bryan said, support for image rips isn't always complete in all players, still it's astounding to what lengths people go and bend the file format specs in order to get everything from a single directory into a single playable file or archive.
Title: setting up a collection of monolithic wavpack files with tags?
Post by: BearcatSandor on 2010-06-06 15:26:51
Thanks for the help folks. I'm just gonna go ahead and do separate files for now. Seems easier to manage anyhow.

Bryant you have a fantastic audio format. It's saved me lots of space over flac, especially the -x option with my many 24 bit files.

Thank you so much for creating it. 

I hope it becomes more of a standard in time.

Bearcat
Title: setting up a collection of monolithic wavpack files with tags?
Post by: bryant on 2010-06-07 06:30:30
Thanks for the kind words about WavPack; I'm very glad it's working out for you! 

David