What is the file size limit in taglib?
Scott Wheeler
wheeler at kde.org
Sun Mar 5 23:01:36 CET 2006
On Saturday 04 March 2006 10:03, Simon Raaf wrote:
> Question: What is the file size limit in taglib?
>
> I do want to traverse my file-system, dvd's, shares etc. getting all kind
> of info (md5, 'tag' info using taglib, etc.), and do have files >16Gb
> (captured videos and music).
>
> When looking for example in mpeg\mpegfile, I see things like:
>
> long MPEG::File::findID3v1()
> {
> if(isValid()) {
> seek(-128, End);
> long p = tell();
>
> if(readBlock(3) == ID3v1::Tag::fileIdentifier())
> return p;
> }
> return -1;
> }
>
> another place (same file):
> int offset = d->hasID3v1 ? -128 : 0;)
>
> I'm just new to c++ but on HP-UX (true Unix) and also Windows signed long
> and int are 4 bytes and by that limited to a range of 2Gb.
Video isn't support by TagLib, which leaves FLAC as the lowest compression
ratio format. Working with FLAC a 2 GB limit would mean files about 36 hours
long.
Now, let's take the 16 GB example and think of writing a tag to that. Most of
the time tags are in the front of the file, and let's say you've got a really
fast hard drive -- that it write 10 MB/s sustained even when it's reading
from a different place on the same drive (note, in the real world I'd expect
half to a quarter of this rate), writing a tag would take half an hour.
I consider 36 hour music files to be, well, kind of a bit out of scope.
-Scott
--
I mean, if 10 years from now, when you are doing something quick and dirty,
you suddenly visualize that I am looking over your shoulders and say to
yourself, "Dijkstra would not have liked this", well that would be enough
immortality for me.
-E. W. Dijkstra
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