From 596265628f267cd0d91f6e834a0f78c591cd8a3e Mon Sep 17 00:00:00 2001 From: tobigun Date: Thu, 10 Apr 2008 15:04:18 +0000 Subject: workaround for erroneously detection of 48000Hz-only devices as 44100Hz devices in portaudio git-svn-id: svn://svn.code.sf.net/p/ultrastardx/svn/trunk@1017 b956fd51-792f-4845-bead-9b4dfca2ff2c --- Game/Code/Classes/UAudioCore_Portaudio.pas | 141 +++++++++++++++++++++++++++++ 1 file changed, 141 insertions(+) (limited to 'Game/Code/Classes/UAudioCore_Portaudio.pas') diff --git a/Game/Code/Classes/UAudioCore_Portaudio.pas b/Game/Code/Classes/UAudioCore_Portaudio.pas index 952b211b..bb0635b3 100644 --- a/Game/Code/Classes/UAudioCore_Portaudio.pas +++ b/Game/Code/Classes/UAudioCore_Portaudio.pas @@ -18,6 +18,7 @@ type TAudioCore_Portaudio = class public class function GetPreferredApiIndex(): TPaHostApiIndex; + class function TestDevice(inParams, outParams: PPaStreamParameters; var sampleRate: Double): boolean; end; implementation @@ -96,4 +97,144 @@ begin end; end; +{* + * Portaudio test callback used by TestDevice(). + *} +function TestCallback(input: Pointer; output: Pointer; frameCount: Longword; + timeInfo: PPaStreamCallbackTimeInfo; statusFlags: TPaStreamCallbackFlags; + inputDevice: Pointer): Integer; cdecl; +begin + // this callback is called only once + result := paAbort; +end; + +(* + * Tests if the callback works. Some devices can be opened without + * an error but the callback is never called. Calling Pa_StopStream() on such + * a stream freezes USDX then. Probably because the callback-thread is deadlocked + * due to some bug in portaudio. The blocking Pa_ReadStream() and Pa_WriteStream() + * block forever too and though can't be used for testing. + * + * To avoid freezing Pa_AbortStream (or Pa_CloseStream which calls Pa_AbortStream) + * can be used to force the stream to stop. But for some reason this stops debugging + * in gdb with a "no process found" message. + * + * Because freezing devices are non-working devices we test the devices here to + * be able to exclude them from the device-selection list. + * + * Portaudio does not provide any test to check this error case (probably because + * it should not even occur). So we have to open the device, start the stream and + * check if the callback is called (the stream is stopped if the callback is called + * for the first time, so we can poll until the stream is stopped). + * + * Another error that occurs is that some devices (even the default device) might + * work at the beginning but stop after a few calls (maybe 50) of the callback. + * For me this problem occurs with the default output-device. The "dmix" or "front" + * device must be selected instead. Another problem is that (due to a bug in + * portaudio or ALSA) the "front" device is not detected every time portaudio + * is started. Sometimes it needs two or more restarts. + * + * There is no reasonable way to test for these errors. For the first error-case + * we could test if the callback is called 50 times but this can take a second + * for each device and it can fail in the 51st or even 100th callback call then. + * + * The second error-case cannot be tested at all. How should we now that one + * device is missing if portaudio is not even able to detect it. + * We could start and terminate Portaudio for several times and see if the device + * count changes but this is ugly. + * + * Conclusion: We are not able to autodetect a working device with + * portaudio (at least not with the newest v19_20071207) at the moment. + * So we have to provide the possibility to manually select an output device + * in the UltraStar options if we want to use portaudio instead of SDL. + *) +class function TAudioCore_Portaudio.TestDevice(inParams, outParams: PPaStreamParameters; var sampleRate: Double): boolean; +var + stream: PPaStream; + err: TPaError; + cbWorks: boolean; + cbPolls: integer; + i: integer; +const + altSampleRates: array[0..1] of Double = (44100, 48000); // alternative sample-rates +begin + Result := false; + + if (sampleRate <= 0) then + sampleRate := 44100; + + // check if device supports our input-format + err := Pa_IsFormatSupported(inParams, outParams, sampleRate); + if(err <> paNoError) then + begin + // we cannot fix the error -> exit + if (err <> paInvalidSampleRate) then + Exit; + + // try alternative sample-rates to the detected one + sampleRate := 0; + for i := 0 to High(altSampleRates) do + begin + // do not check the detected sample-rate twice + if (altSampleRates[i] = sampleRate) then + continue; + // check alternative + err := Pa_IsFormatSupported(inParams, outParams, altSampleRates[i]); + if (err = paNoError) then + begin + // sample-rate works + sampleRate := altSampleRates[i]; + break; + end; + end; + // no working sample-rate found + if (sampleRate = 0) then + Exit; + end; + + // FIXME: for some reason gdb stops after a call of Pa_AbortStream() + // which is implicitely called by Pa_CloseStream(). + // gdb's stops with the message: "ptrace: no process found". + // Probably because the callback-thread is killed what confuses gdb. + {$IF Defined(Debug) and Defined(Linux)} + cbWorks := true; + {$ELSE} + // open device for testing + err := Pa_OpenStream(stream, inParams, outParams, sampleRate, + paFramesPerBufferUnspecified, + paNoFlag, @TestCallback, nil); + if(err <> paNoError) then + begin + exit; + end; + + // start the callback + err := Pa_StartStream(stream); + if(err <> paNoError) then + begin + Pa_CloseStream(stream); + exit; + end; + + cbWorks := false; + // check if the callback was called (poll for max. 200ms) + for cbPolls := 1 to 20 do + begin + // if the test-callback was called it should be aborted now + if (Pa_IsStreamActive(stream) = 0) then + begin + cbWorks := true; + break; + end; + // not yet aborted, wait and try (poll) again + Pa_Sleep(10); + end; + + // finally abort the stream + Pa_CloseStream(stream); + {$IFEND} + + Result := cbWorks; +end; + end. -- cgit v1.2.3