Extensions, mods

[Allan Sandfeld Jensen]

On Thursday 30 August 2007 23:05, Linus Walleij wrote:
> 2. Add abstraction for "TLEN" in ID3v2 to be
>    written/read as and audioproperty. The idea is to
>    let TLEN take precedence when getting playlength.
>    Some people
>    believe this is superfluous since the info is on the stream
>    itself, but I think it's useful on things that are VBR and
>    missing Xing tags, since it speeds up songlength
>    retrieveal. (Let me know what you think, I managed to
>    have this property added to cmdline "lame" version
>    3.98, forthcoming so there WILL be files with TLEN
>    tags in foreseeable future). Expose as abstract
>    property, add to C API.
>
An VBR MP3 should always have a Xing tag. MP3 should normally always be CBR, 
making the bitrate variable is essentially a new format. The new format is 
recognized by looking for the Xing header, without the Xing header the file 
is not only invalid but many tools will treat it wrong (like a 
standard-compliant CBR MP3). For more accurate file-length of CBR files, you 
can use the INFO tag.

`Allan