HydrogenAudio

Lossless Audio Compression => WavPack => Topic started by: CoRoNe on 2010-08-17 22:52:38

Title: How to extract tags only?
Post by: CoRoNe on 2010-08-17 22:52:38
Hello,

I have a WV-file with embedded cue-sheet and cover-art. I'd like to know how to extract both of these with wvunpack.exe WITHOUT having to extract the audio itself.
I've actually already managed to do this with "wvunpack -cc -xx "Cover Art (Front)"", and after that quickly hit Ctrl+C to stop the WAV-file extraction.
However the primary command for this would be: "wvunpack -c -x "Cover Art (Front)"", but since this is then forwarded to stdout, no actual files are extracted.
I get the following messages:
Code: [Select]
can't extract more than 1 tag item to stdout at a time!
can't extract a tag to stdout and do anything else!
Press any key to continue . . .

I have read this however:
Quote
-s = display summary information only to stdout (no decode)

This option causes WvUnpack to simply display general information about the specified WavPack files including source information, encoder version and
options and original MD5 checksum. This information can be directed into a file with the ">" operator. No file decoding or verification can occur with this option.
So I guess for people only wanting to extract certain tags without the audio, there's something missing from the manual? I tried some variations with the ">" in it, but nothing worked.
Title: How to extract tags only?
Post by: bryant on 2010-08-18 04:39:34
So I guess for people only wanting to extract certain tags without the audio, there's something missing from the manual? I tried some variations with the ">" in it, but nothing worked.

Yeah, the syntax and behavior is a little confusing. If you do not want to decode audio, then you need to use stdout for all tag decoding and (obviously) need one command line for each tag:

Code: [Select]
wvunpack file.wv -x "Cover Art (Front)" > cover.jpg
wvunpack file.wv -c > cuesheet.cue

BTW, I have not tried these with the frontend (which it looks like you might be using), so there might be a problem there with using stdout.

I could add a new switch like --no-audio-decode to force the behavior you want, and I also thought about a switch --extract-all-tags that would extract all multi-line and binary tags, but I decided it was already getting too confusing... 

David
Title: How to extract tags only?
Post by: CoRoNe on 2010-08-18 11:26:02
Ah yes, Multi frontend automatically fills in %s and %d, so you're right. Using only the command-tool worked. However, with -cc and -xx wvunpack.exe automatically names the jpg-file "Cover Art (Front).jpg" and the cue-file "[file-name.wv].cue", where as with -c and -x entering a name seems to be mandatory, because something like "*.jpg" doesn't work.
A new switch for extracting tags is also welcome. Thanks for your time.