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wasapi:

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- fixed alignment missing for host buffer if overall buffer size was set to less than 3ms that results in device timeout
 - advanced Event driven mode and extended the range of host buffer size which can operate in this mode up up to 20.66 ms, e.g. your device buffer size will vary in range 3 - 20.66 ms, if goes above then Poll driven mode is switched on automatically
This commit is contained in:
dmitrykos 2010-08-06 20:25:07 +00:00
commit 9c7974c76c
2 changed files with 13 additions and 5 deletions
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4
include/pa_win_wasapi.h
View file

@ -346,8 +346,8 @@ PaError PaWasapi_GetJackDescription(PaDeviceIndex nDevice, int jindex, PaWasapiJ
1) Event-Driven:
This is the most powerful WASAPI implementation which provides glitch-free
audio at around 3ms latency in Exclusive mode. Lowest possible latency for this mode is
usually - 1.4(Vista only)-3ms(Windows 7+) for HD Audio class audio chips. For the
Shared mode latency can not be lower than 20ms.
3 ms for HD Audio class audio chips. For the Shared mode latency can not be
lower than 20 ms.
2) Poll-Driven:
Polling is another 2-nd method to operate with WASAPI. It is less efficient than Event-Driven

14
src/hostapi/wasapi/pa_win_wasapi.c
View file

@ -2094,7 +2094,7 @@ static HRESULT CreateAudioClient(PaWasapiStream *pStream, PaWasapiSubStream *pSu
// Use Polling if overall latency is > 5ms as it allows to use 100% CPU in a callback,
// or user specified latency parameter
overall = MakeHnsPeriod(framesPerLatency, pSub->wavex.Format.nSamplesPerSec);
if ((overall > 50000) || (params->suggestedLatency > 0))
if ((overall >= (106667*2)/*21.33ms*/) || ((INT32)(params->suggestedLatency*100000.0) != 0/*0.01 msec granularity*/))
{
framesPerLatency = PaUtil_GetFramesPerHostBuffer(userFramesPerBuffer,
params->suggestedLatency, pSub->wavex.Format.nSamplesPerSec, 0/*,
@ -2124,12 +2124,22 @@ static HRESULT CreateAudioClient(PaWasapiStream *pStream, PaWasapiSubStream *pSu
if (pSub->shareMode == AUDCLNT_SHAREMODE_SHARED)
{
if (pSub->period < pInfo->DefaultDevicePeriod)
{
pSub->period = pInfo->DefaultDevicePeriod;
// Recalculate aligned period
framesPerLatency = MakeFramesFromHns(pSub->period, pSub->wavex.Format.nSamplesPerSec);
_CalculateAlignedPeriod(pSub, &framesPerLatency, ALIGN_BWD);
}
}
else
{
if (pSub->period < pInfo->MinimumDevicePeriod)
{
pSub->period = pInfo->MinimumDevicePeriod;
// Recalculate aligned period
framesPerLatency = MakeFramesFromHns(pSub->period, pSub->wavex.Format.nSamplesPerSec);
_CalculateAlignedPeriod(pSub, &framesPerLatency, ALIGN_BWD);
}
}
/*! Windows 7 does not allow to set latency lower than minimal device period and will
@ -2152,7 +2162,6 @@ static HRESULT CreateAudioClient(PaWasapiStream *pStream, PaWasapiSubStream *pSu
if (pSub->period > MAX_BUFFER_EVENT_DURATION)
{
pSub->period = MAX_BUFFER_EVENT_DURATION;
// Recalculate aligned period
framesPerLatency = MakeFramesFromHns(pSub->period, pSub->wavex.Format.nSamplesPerSec);
_CalculateAlignedPeriod(pSub, &framesPerLatency, ALIGN_BWD);
@ -2163,7 +2172,6 @@ static HRESULT CreateAudioClient(PaWasapiStream *pStream, PaWasapiSubStream *pSu
if (pSub->period > MAX_BUFFER_POLL_DURATION)
{
pSub->period = MAX_BUFFER_POLL_DURATION;
// Recalculate aligned period
framesPerLatency = MakeFramesFromHns(pSub->period, pSub->wavex.Format.nSamplesPerSec);
_CalculateAlignedPeriod(pSub, &framesPerLatency, ALIGN_BWD);