[Vorbis] Oggenc producing a different file every time

[Gregory Maxwell]

On Thu, Nov 29, 2012 at 10:16 AM, Joost van Dongen
<joost at ronimo-games.com> wrote:
> We are using the Ogg file format in our game Awesomenauts. Now whenever I
> rebuild our compressed music files from our uncompressed sources (WAV to
> OGG), oggenc.exe produces different files. They sound the same, but there
> are differences in the file. I did a checksum on the hex, and it turns out
> there are small pieces of similar differences throughout the file.

Every ogg logical stream has a serial number. This serial number is
selected at random so you can usually create chained files through
straight concatenation.

For oggenc,

       -s, --serial
              Forces a specific serial number in the output stream.
This is primarily useful for testing.