[flac] md5 checksum

[Harry Sack]

2007/10/19, Josh Coalson <xflac at yahoo.com>:
>
> --- Harry Sack <tranzedude at gmail.com> wrote:
> > hi
> >
> > here some questions about the md5 checksum:
> >
> > - what happens when the md5 checksum of the decoded audio is
> > different
> > of the internally stored checksum due to file corruption ? Will
> > playing/decoding still be possible (with some error frames) or will
> > playing /decoding be not possible at all (so all audio data is lost)?
>
> md5 does not affect decoding at all, it is a just a checksum to
> tell you at the end if it matches the whole audio or not.



thanks for the answer, but then there is wrong information on some sites
that tell about flac :s.
There is written the flac decoder doesn't decode the audio at all when the
md5 checksum doesn't match.

> - what happens when the metadata blocks get corrupt? will the audio
> > part still be decodable even when non-audio blocks are corrupt?
>
> yes
>
> > - since there is only a md5 checksum on the audio blocks itself, what
> > happens when some wav metadata gets corrupt and you want to decode
> > that data? How can the decoder detect it's corrupt or not because
> > there is no md5 checksum for this data?
>
> depends on the corruption, some kinds are recoverable, some are not.
> read the format spec first and it should become clear.



Why is there no md5 checksum on the WAV metadata? Because how can flac
otherwise be called a 'lossless' codec when the metadata of the WAV file
can't be guaranteed 100% identical to the original, when there is file
corruption, because there is no md5 checksum on it?

thx
Harry

Josh
>
>
> __________________________________________________
> Do You Yahoo!?
> Tired of spam?  Yahoo! Mail has the best spam protection around
> http://mail.yahoo.com
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.xiph.org/pipermail/flac/attachments/20071019/e3dc1d59/attachment.html