Resampler delay for N taps is N/2-1 input samples.
Add test that checks this.
When input rate is varying, the resampler also accumulates additional
sub-sample delay. The resampler does not currently have API to report
the instantaneous sub-sample delay. Add knownfail test for it.
While this is quite fast on x86 (order of a few microseconds), the
computation can take a few milliseconds on ARM (measured at 1.9ms (32000
-> 48000) and 3.3ms (32000 -> 44100) on a Cortex A53).
Let's precompute some common rates so that we can avoid this overhead on
each stream (or any other audioconvert) instantiation. The approach
taken here is to write a little program to create the resampler
instance, and run that on the host at compile-time to generate some
common rate conversions.
We need to do dithering and noise when converting f32 to the
target format. This is more natural because we can work in 32 bits
integers instead of floats.
This will also make it possible to actually calculate the error between
source and target values and implement some sort of feedback and
noise shaping later.
Rename empty.noise -> dither.noise and always add this amount of noise
when > 0. This also adds the noise to silent sounds, not only when
nothing is connected because that would also be a problem when an amp
needs to be kept alive with an non-0 signal.
Rename noise -> dither because we can use this also for dithering later.
See #705
Add an empty.noise option that specifies the number of bits to
use for noise when the input signal is pure silence.
Some amplifiers can go into suspend mode pretty easily when they
get pure silence. With empty.noise = 1, audioconvert will now generate
a bitpattern that can keep those amplifiers alive, together with
disabling suspend in the session manager.
Fixes#705
Since 01c6fd0a88 the
minimum required meson version is 0.59.0, and since
meson 0.58.0, `get_variable()` on a dependency object
accepts a positional argument. The "type" of variable
(internal, pkgconfig, etc.) in that case does not need
to be specified explicitly.
Use `meson.project_{build,source}_root()` instead of
`meson.{build,source}_root()` because those functions
do not work as expected when used inside a subproject,
and they have been deprecated in meson 0.56.0.
For SPA libraries that we link against elsewhere in the tree, declare a
declare a dependency "foo_dep" for that library that specifies how to
link to it. Then use that dependency in the various targets.
This removes the knowledge of how to link with the library from the
target which can treat it as just another dependency.
In the case of optional libraries (e.g. the journal support lib) we can
then use declare_dependency() to declare an empty dependencies and thus
link them unconditionally in the target.
This makes installed-tests (see commit b852b58f) do the right thing.
For build-time testing, spa/plugins/audioconvert/meson.build overrides
this with the SPA_PLUGIN_DIR environment variable, and for ad-hoc
testing by developers, pw-uninstalled.sh sets the necessary variables.
Signed-off-by: Simon McVittie <smcv@debian.org>
This makes it easier to test PipeWire in its "as-installed" state,
for example in an OS distribution.
The .test metadata files in ${datadir}/installed-tests/${package} are
a convention taken from GNOME's installed-tests initiative, allowing a
generic test-runner like gnome-desktop-testing to discover and run tests
in an automatic way.
The installation path ${libexecdir}/installed-tests/${package} is also
a convention borrowed from GNOME's installed-tests initiative.
In addition to the automated tests, I've installed example executables
in the same place, for manual testing. They could be separated into
a different directory if desired, but they seem like they have more
similarities with the automated tests than differences: both are there
to test that PipeWire works correctly, and neither should be relied on
for production use. Some examples are installed in deeper subdirectories
to avoid name clashes.
Signed-off-by: Simon McVittie <smcv@debian.org>
