StartStream() calls WaitForSingleObject(stream->hThreadStart, 60*1000)
but it will not be able to return until X number of PaStreamCallback
have been performed by ProcessOutputBuffer().
The above behaviour will cause a deadlock if the user supplied
PaStreamCallback tries to access a shared lock currently held by the
function calling Pa_StartStream().
Also it's a bit weird that you start receiving PaStreamCallbacks
before Pa_StartStream() is able to complete.
- Implement workaround for system timer coarse granularity causing underruns by using timeBeginPeriod/timeEndPeriod APIs inside the Event and Poll thread handlers.
- Update next sleep time of the Poll rendering loop dynamically depending on time taken for processing/rendering of audio data into the available host buffer to avoid underruns and fit processing time into periodic polling time slots.
- Add support for time slots logging in Poll mode if PA_WASAPI_LOG_TIME_SLOTS is defined. Fixed audible glitches by preloading the whole host buffer before stream is started.
- Fix audible glitches on stream start by preloading the whole host buffer before stream is started.
AUDCLNT_STREAMFLAGS_AUTOCONVERTPCM is required in order to allow for sample rates other than the system mixer configured sample rate. Otherwise, WASAPI is limited to a single system configured sample rate in Shared mode, which is a severe limitation compared to other APIs supported by PortAudio.
AUDCLNT_STREAMFLAGS_SRC_DEFAULT_QUALITY is recommended to be used additionally.
See <https://docs.microsoft.com/en-us/windows/desktop/coreaudio/audclnt-streamflags-xxx-constants> for documentation.
GetClosestFormat is modified to exit early when paWinWasapiAutoConvert is set in Shared mode because we trust the WASAPI conversions to succeed.
We restrict these changes to Windows 7 (and later) because documentation does not clearly state the minimum required Windows version. Windows Vista was not available for testing.
This patch has been in production in OpenMPT (<https://openmpt.org/>) since version 1.27.01.00 (2017-09-27). PortAudio WASAPI Shared mode is the default output device type in OpenMPT for Windows 7 (and later) and also for Wine setups.
- support for explicit 8.24 format (24-bit inside 32-bit container) by specifying paCustomFormat (see IMPORTANT notes in the header file);
- new flag paWinWasapiExplicitSampleFormat to force explicit format and avoid fallback to a closest working;
- new function PaWasapi_GetDeviceCurrentFormat to get device format of the opened stream;
- support PaWasapi_ThreadPriorityXXX API on UWP to boot thread priority;
- improved selection of the closest format in Exclusive mode.
This new implementation overcomes current limitation of Pa_GetDeviceCount() API which gives constant device count by making WASAPI device list constant (32 devices by default) where 32 device slots can either be filled with a real device info or be empty for a future device changes.
Constant device list size can be altered by PA_WASAPI_MAX_CONST_DEVICE_COUNT define during a compile time. If PA_WASAPI_MAX_CONST_DEVICE_COUNT is set to 0 then PaWasapi_UpdateDeviceList() will be unavailable as well as dynamic device list update functionality.
This implementation also detects the audio device format change if user alters it via Windows Audio Controller GUI.
This implementation also makes WASAPI backend ready for a future implementation of device list updates via PortAudio public API. See internal PaError UpdateDeviceList().
wasapi: use IAudioClient3 for Windows 10 for best compatibility
wasapi: fix compilation when Windows 10 SDK (10.0.15063.0) is used by removing SignalObjectAndWait() definition which creates duplicates with the system defined SignalObjectAndWait() (since 10.0.15063.0 it is supported by the OS again)
