FLAC's standard container format is not Ogg.  You can put FLAC in an Ogg container, but it's rather uncommon and the FLAC FAQ recommends against it.  (Not because it will mess anything up, but rather because it is pointless.)<p>FLAC's container format supports arbitrary seekpoints, but it seems many encoders do not add them.  Add them and a seek is a constant-time operation.