FLAC-in-Matroska Files, now i'm switch to CoreFLACDecoder. :) It's wired, the ffdshow(20050122) can decode the MKV-FLAC with old Official Matroska splitter, but the new Haali matroska spltter can't I'm not sure it's splitter or decoder problem, but i've sent the bug report to the ffdshow developer.