[Flac-dev] Decoded files identical, encoded files different (linux vs win encoder)

[Erik de Castro Lopo]

Djeizon Barros wrote:

> > Another possibility could be different line endings in some
> > metadata file (ie '\r\n' on windows and '\n' on Linux).
> > 
> 
> The produced files are tagless. So I don't know about this... but
> it is a good guess

Its a good guess and its wrong :-).

> I have uploaded a small file example for you to check.
> I am curious about what is exactly producing this mismatch filesize!
> I know it's ridiculous and probably too paranoid, but knowledge is always welcome.
> 
> 
> -rw-r--r-- 1 djzn djzn 341418 2010-02-11 20:34 bandstand-linux.flac
> -rw-r--r-- 1 djzn djzn 556308 2010-02-11 20:34 bandstand.wav
> -rw-r--r-- 1 djzn djzn 341429 2010-02-11 20:34 bandstand-win32.flac

Wow, this is weird.

I have a program thats part of libsndfile called sndfile-cmp. Run as:

    sndfile-cmp bandstand-linux.flac bandstand-win32.flac

it shows nothing which means that the decoded audio of the two files is
identical.

However, I also have a hexdiff program which shows the two files to contain
the identical byte data all the way  up to offset 0x2080. Then the files
diverge wildly:

00002070:  FF F8 C9 A8 00 8D 4E 00  00 00 00 FF FF FF FF FF   ......N. ........
           FF F8 C9 A8 00 8D 4E 00  00 00 00 FF FF FF FF FF   ......N. ........

00002080:  FF FF FE FF FE FF FE B4  A2 7D E8 9D 2E 79 91 47   ........ .}...y.G
           FF FF FE FF FE FF FE B4  A2 7D E8 9D 36 79 11 47   ........ .}..6y.G

00002090:  57 05 9F DD 0A 2A 54 52  A5 13 13 2D 4B 2C B2 94   W....*TR ...-K,..
           57 05 9F DD 0A 2A 54 52  A5 13 13 2D 4B 2C 59 4A   W....*TR ...-K,YJ

000020A0:  95 6A 2D 25 24 85 95 96  26 49 0A 13 53 A9 24 51   .j-%$... &I..S.$Q
           4A B5 16 92 92 42 CA CB  13 24 85 09 A9 D4 92 28   J....B.. .$.....(

The first column is the file offset and the first line for a given offset
is one file and the second line is the second file.