Add pitch tests with different forward and backward playback rates.
Those tests depend on the libSoundTouch version to validate the buffers
checksums. The actual version uses libSoundTouch 2.3.2, use the
`--force-fallback-for=soundtouch` meson option to build using the same
version.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6247>
- fully protect accesses to the libsoundtouch API that is not
thread-safe.
- fully protect accesses to GstPitch members that could be read by a
downstream query thread while written by an upstream streaming thread
or a user thread.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6247>
- use the `GST_PITCH_GET_PRIVATE` accessor when needed
- rename `out_seg_rate` to `output_rate` to use the same name as the parameter
- rename `seg_arate` to `segment_applied_rate` to improve readability
- apply gst-indent to gstpitch.hh/cc
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6247>
When changing playing rate, the output segment was not correctly
calculated because the stream time ratio was computed using the previous
input segment rate instead of using the actual rate. This was producing
wrong results for the output segment start and end values.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/6247>