Thanks, guys. Your answers helped and I think I have some ideas now on what to do. On Wednesday, March 6, 2019 Miroslav Lichvar <mlich...@redhat.com> wrote: On Tue, Mar 05, 2019 at 10:26:54PM -0800, Brian Willoughby wrote: > Frames start with a 14-bit sync code, which is 13 “one" bits and 1 “zero" > bit. Subframes start with a 1-bit padding of “zero." Keep in mind that FLAC > is a bit stream, not a byte stream, so that 14-bit frame sync can happen > anywhere in a pair of bytes. You can’t simply scan memory bytes for a frame > sync, at least not unless you allow for 8 variations, apply bit masks, and > allow for non-word-address-aligned matches.
The specification says frames are aligned to bytes: Following the frame header are encoded subframes, one for each channel, and finally, the frame is zero-padded to a byte boundary. The problem with finding frame boundaries is that the sync code and the 8-bit CRC are too short, so the whole frame needs to be parsed and the 16-bit CRC checked to be reasonably sure it really is a FLAC frame. -- Miroslav Lichvar
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