Martin Leese wrote: > I am also puzzled why anyone would want > FLAC to reject a valid WAVE-EX file.
> The FLAC spec at: > https://xiph.org/flac/format.html > > states: > Again, since a decoder may start decoding at an arbitrary frame in the > stream, each frame header must contain some basic information about > the stream because the decoder may not have access to the STREAMINFO > metadata block at the start of the stream. This information includes > sample rate, bits per sample, number of channels, etc. > > So, for a FLAC file to be streamable then the > four "Channel assignment" bits in > FRAME_HEADER must actually repeat the > number of channels (initially specified in the > STREAMINFO block). The "Channel > assignment" bits in FRAME_HEADER also > contain the Channel assignment and, when > these two uses of the same four bits are in > conflict, a different channel assignment can > be specified in the FLAC tag > WAVEFORMATEXTENSIBLE_CHANNEL_MASK. > (If the two uses of the "Channel assignment" > bits in FRAME_HEADER do not conflict then > the FLAC tag serves no purpose.) If a decoder may not have access to STREAMINFO block then it also cannot read VORBIS_COMMENT block, so it cannot read WAVEFORMATEXTENSIBLE_CHANNEL_MASK tag and will decode a FLAC stream using the default (incorrect) channel assignment. So the files that have non-default channel assignment are probably not Subset compatible. IMHO it's necessary at least to warn a user about it. _______________________________________________ flac-dev mailing list [email protected] http://lists.xiph.org/mailman/listinfo/flac-dev
