[PATCH] flac export enhancement


I’m currently working with long recordings, 4-6h. I choosed flac to save some space and to keep metadata with them.

Audacity lacks two features for flac export:

  1. SEEKTABLE (index)
    Without, no player can seek.
    In the flac docs looks like they recommand 1 seekpoint/10 seconds, so I enabled this by default
    This costs e.g. ~32k for a 5.5h stereo file (2.2GiB).
    I’m still playing with the values, needs some more testing with players. Maybe better is 1sk-pt/sec

    Since metadata is stored at the beginning of a FLAC file, increasing the length or number of meta tags (this includes also the seektable), can cause the whole file to be rewritten. This can be avoided by adding some padding bytes.
    0 disables,
    8k default (good for small files)
    64k don’t hurt on xxx GiB files

This is my first hack on Audacity. I hope it’s ok that way. May a native english speaker look at it and update the docs?
I tested the resulting files with the ‘metaflac’ tool and with kid3 http://kid3.sourceforge.net

Works for me.

Well, I guess next ppl start asking for a CUESHEET option … would be nice :wink: and the flac api has some support …
flac-export.patch (9.64 KB)

funny you should say that - have a look at this page in the Wiki: http://wiki.audacityteam.org/wiki/Cue_sheets

You may want to add your vote …


I knew it. I knew it! :mrgreen:

By the way: just saw an error in my patch. Nothing serious.

2 cents to go …