Currently the last backend error string is only set when calling
AudioBackend::start. Errors that occur when calling other AudioBackend methods
like AudioBackend::set_buffer_size do not set the last backend error string.
So until all the required AudioBackend methods return an ErrorCode and
last_backend_error() can be removed just set it to a default string.
Until all errors that occur are correctly indicated by returning an error code
there will still be situations where last_backend_error() is not indicative of
the true error. For instance AudioEngine::start is called and it fails but
returns a valid error code so last_backend_error() is set, then some other
engine/backend method is called that fails and as last_backend_error is not
set the GUI will display the incorrect error message.
This will allow backends to return a more meaningful error message. Eventually
an error code could be returned by AudioEngine::start and the GUI can then use
AudioBackend::get_error_string to convert the error into a translated error
message directly, or it may be desirable to define its own error messages.
The reasons for not doing that right now is that this is a workable solution
with the least change required.
The peak meter needs to withstand various test-signals
without visual jitter (in particular 1kHz sine) regardless
of settings (period-size, sample-rate, custom fall-off).
This needs to be done in sync (and not by a random non-rt
‘smoothing’ thread).
On the downside this voids the ‘visual smoothing’ particularly
with large buffersizes - but then again exactly this “always
fall-off no matter what [the next real data will be]” is the
problem.
One the upside, there’s one less high-frequency (100Hz) thread
(Yay!) PS. it probably never worked on windows, anyway.
Only peak-meters are affected by his change.
K-meters, IEC I/II and VU were never visually smoothed.
1) Disambiguate 1.0 to GAIN_COEFF_UNITY, and 0.0 to GAIN_COEFF_ZERO
2) Add GAIN_COEFF_SMALL which replaces SMALL_SIGNAL (-140dB)
3) GAIN_COEFF_SMALL can used to avoid interpolating towards -inf on a db scale
4) GAIN_COEFF_SMALL is used to detect very small (denormal?) gains and memset to zero
Made correct error handling for cases we didn't see before.
Removed redundant and experimental code I forgot to remove months ago.
Added debug output which will help in future testing
Conflicts:
libs/ardour/ardour/audioengine.h
libs/ardour/engine_state_controller.cc
libs/backends/wavesaudio/waves_midi_device.cc
MidiPort::cycle_end() was never called, hence after the
first cycle all midi buffers were assumed to be
“mixed down” already.
this fixes
Midi-track 1 -[midi]-> Midi-track2 synth -[audio]-> out
on export.
backends - once instantiated - keep a reference to the engine.
when audioengine is destroyed, the backends must be deinstantiated.
This fixes various unit-test cases.
see: https://github.com/fundamental/stoat
eventually more functions should be annotated, and
a common header file should be used to
#define REALTIME __attribute__((annotate("realtime")))
