[flac-dev] [PATCH] stream_encoder : Improve selection of residual accumulator width

[lvqcl]

Miroslav Lichvar wrote:

> I think it would be interesting to know how common are such streams. I
> patched flac to print a warning on decoding or testing when this is
> detected, but didn't find any files with this problem in my (small)
> music collection.
>
> If someone has a large collection and some cycles to spare, can you please
> consider compiling flac from git with the attached patch and see if
> you have any files that fail with "flac -t" ?
>
> With the known problem file (snippet6.wav) encoded by 1.3.0 it prints
> this:
>
> WARNING: residual -11025151 wider than bps 24
> WARNING: residual 41873263 wider than bps 24
> WARNING: residual -67175215 wider than bps 24
> WARNING: residual 69950995 wider than bps 24
> WARNING: residual -67108864 wider than bps 24
> ...
> WARNING: residual 11227392 wider than bps 24
> WARNING: residual -8754288 wider than bps 24
> snippet6.flac: ERROR, MD5 signature mismatch

It seems quite common for 16-bit files:

WARNING: residual 43536 wider than bps 16
WARNING: residual 38012 wider than bps 16
WARNING: residual 35263 wider than bps 16
WARNING: residual 40668 wider than bps 16
WARNING: residual -34199 wider than bps 16
WARNING: residual -33828 wider than bps 16
WARNING: residual -33891 wider than bps 16
WARNING: residual -33540 wider than bps 16
WARNING: residual -36793 wider than bps 16
WARNING: residual -38870 wider than bps 16
WARNING: residual -35610 wider than bps 16
WARNING: residual -39849 wider than bps 16
WARNING: residual -38411 wider than bps 16
WARNING: residual -33430 wider than bps 16
WARNING: residual -34989 wider than bps 16

I don't have 24-bit FLAC files in my music library.