MPD uses soxr with prefined resample recipes. Soxr also support defining a recipe your self.
This commit will support a custom recipe by changing the existing quality setting to "custom".
The same structs as the predefined recipes uses can now set by hand.
This will make the following settings available:
- precision 16|20|24|28|32 bits, example "28"
- phase_response - 0-100, example "45"
- passband_end - used bandwidth of source 80-99.7%, example "99.7.0"
- stopband_begin - anti aliasing 100.0+%, example "100".
- attenuation - signal reduciton in dB's, 0-30. example "3.0".
- flags "0" - additional bitmask with extra settings
The data is set in the structs soxr_quality_spec and soxr_io_spec (found in soxr.h).
The former was deprecated with C++14.
According to the C++11 and C++17 standards, both files are identical.
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Since we switched from autotools to Meson in commit
94592c1406, we don't need to include
`config.h` early to properly enable large file support. Meson passes
the required macros on the compiler command line instead of defining
them in `config.h`.
This means we can include `config.h` at any time, whenever we want to
check its macros, and there are no ordering constraints.
The old formula calculates the output buffer size with "regular"
rounding (to the nearest integer), however sometimes, that is
insufficient and the last sample cannot be resampled. This causes
audible distortions. By changing the formula to consider the worst
case (always round up), this problem is eliminated.
