- device input latency is now configurable via config.ini

- latency[i] determines the latency for device i in milliseconds or -1 for autodetection (default)
- this is necessary as mic capturing with portaudio (on linux) gets stuck if latency is too low. Either because portaudio's latency autodetection does not work or because the mic capture callback takes too long before it returns. In both cases the user should set the latency to a value of 100 (ms).
- better input device test, it should not remove working devices anymore.

git-svn-id: svn://svn.code.sf.net/p/ultrastardx/svn/trunk@2313 b956fd51-792f-4845-bead-9b4dfca2ff2c

1 files changed, 48 insertions, 17 deletions

diff --git a/src/media/UAudioInput_Portaudio.pas b/src/media/UAudioInput_Portaudio.pas
index 26919d42..92e549ff 100644
--- a/src/media/UAudioInput_Portaudio.pas
+++ b/src/media/UAudioInput_Portaudio.pas
@@ -45,6 +45,7 @@ uses
   portmixer,
   {$ENDIF}
   portaudio,
+  ctypes,
   UAudioCore_Portaudio,
   UUnicodeUtils,
   UTextEncoding,
@@ -77,18 +78,19 @@ type
       function Start(): boolean; override;
       function Stop():  boolean; override;
 
+      function DetermineInputLatency(Info: PPaDeviceInfo): TPaTime;
+
       function GetVolume(): single;        override;
       procedure SetVolume(Volume: single); override;
   end;
 
-function MicrophoneCallback(input: pointer; output: pointer; frameCount: longword;
+function MicrophoneCallback(input: pointer; output: pointer; frameCount: culong;
       timeInfo: PPaStreamCallbackTimeInfo; statusFlags: TPaStreamCallbackFlags;
-      inputDevice: pointer): integer; cdecl; forward;
+      inputDevice: pointer): cint; cdecl; forward;
 
-function MicrophoneTestCallback(input: pointer; output: pointer; frameCount: longword;
+function MicrophoneTestCallback(input: pointer; output: pointer; frameCount: culong;
       timeInfo: PPaStreamCallbackTimeInfo; statusFlags: TPaStreamCallbackFlags;
-      inputDevice: pointer): integer; cdecl; forward;
-
+      inputDevice: pointer): cint; cdecl; forward;
 
 {**
  * Converts a string returned by Portaudio into UTF8.
@@ -106,6 +108,33 @@ end;
 
 { TPortaudioInputDevice }
 
+function TPortaudioInputDevice.DetermineInputLatency(Info: PPaDeviceInfo): TPaTime;
+begin
+  if (Ini.InputDeviceConfig[CfgIndex].Latency <> -1) then
+  begin
+    // autodetection off -> set user latency
+    Result := Ini.InputDeviceConfig[CfgIndex].Latency / 1000
+  end
+  else
+  begin
+    // on vista and xp the defaultLowInputLatency may be set to 0 but it works.
+    // TODO: correct too low latencies (what is a too low latency, maybe < 10ms?)
+    // TODO: retry with input-latency set to 20ms (defaultLowInputLatency might
+    //       not be set correctly in OSS)
+
+    // FIXME: according to the portaudio headers defaultHighInputLatency (approx. 40ms) is
+    // for robust non-interactive  applications and defaultLowInputLatency (approx. 15ms)
+    // for interactive performance.
+    // We need defaultLowInputLatency here but this setting is far too buggy. If the callback
+    // does not return quickly the stream will be stuck after returning from the callback
+    // and the callback will not be called anymore and mic-capturing stops.
+    // Audacity (in AudioIO.cpp) uses defaultHighInputLatency if software playthrough is on
+    // and even higher latencies (100ms) without playthrough so this should be ok for now.
+    //Result := Info^.defaultLowInputLatency;
+    Result := Info^.defaultHighInputLatency;
+  end;
+end;
+
 function TPortaudioInputDevice.Open(): boolean;
 var
   Error:       TPaError;
@@ -126,12 +155,12 @@ begin
     device := PaDeviceIndex;
     channelCount := AudioFormat.Channels;
     sampleFormat := paInt16;
-    suggestedLatency := deviceInfo^.defaultLowInputLatency;
+    suggestedLatency := DetermineInputLatency(deviceInfo);
     hostApiSpecificStreamInfo := nil;
   end;
 
-  //Log.LogStatus(deviceInfo^.name, 'Portaudio');
-  //Log.LogStatus(floattostr(deviceInfo^.defaultLowInputLatency), 'Portaudio');
+  Log.LogStatus('Open ' + deviceInfo^.name, 'Portaudio');
+  Log.LogStatus('Latency of ' + deviceInfo^.name + ': ' + floatToStr(inputParams.suggestedLatency), 'Portaudio');
 
   // open input stream
   Error := Pa_OpenStream(RecordStream, @inputParams, nil,
@@ -309,6 +338,8 @@ var
   sourceIndex:  integer;
   sourceName:   UTF8String;
   {$ENDIF}
+const
+  MIN_TEST_LATENCY = 100 / 1000; // min. test latency of 100 ms to avoid removal of working devices
 begin
   Result := false;
 
@@ -354,13 +385,13 @@ begin
 
     sampleRate := paDeviceInfo^.defaultSampleRate;
 
-    // on vista and xp the defaultLowInputLatency may be set to 0 but it works.
-    // TODO: correct too low latencies (what is a too low latency, maybe < 10ms?)
-    latency := paDeviceInfo^.defaultLowInputLatency;
+    // use a stable (high) latency so we do not remove working devices
+    if (paDeviceInfo^.defaultHighInputLatency > MIN_TEST_LATENCY) then
+      latency := paDeviceInfo^.defaultHighInputLatency
+    else
+      latency := MIN_TEST_LATENCY;
 
     // setup desired input parameters
-    // TODO: retry with input-latency set to 20ms (defaultLowInputLatency might
-    //       not be set correctly in OSS)
     with inputParams do
     begin
       device := paDeviceIndex;
@@ -488,9 +519,9 @@ end;
 {*
  * Portaudio input capture callback.
  *}
-function MicrophoneCallback(input: pointer; output: pointer; frameCount: longword;
+function MicrophoneCallback(input: pointer; output: pointer; frameCount: culong;
       timeInfo: PPaStreamCallbackTimeInfo; statusFlags: TPaStreamCallbackFlags;
-      inputDevice: pointer): integer; cdecl;
+      inputDevice: pointer): cint; cdecl;
 begin
   AudioInputProcessor.HandleMicrophoneData(input, frameCount*4, inputDevice);
   result := paContinue;
@@ -499,9 +530,9 @@ end;
 {*
  * Portaudio test capture callback.
  *}
-function MicrophoneTestCallback(input: pointer; output: pointer; frameCount: longword;
+function MicrophoneTestCallback(input: pointer; output: pointer; frameCount: culong;
       timeInfo: PPaStreamCallbackTimeInfo; statusFlags: TPaStreamCallbackFlags;
-      inputDevice: pointer): integer; cdecl;
+      inputDevice: pointer): cint; cdecl;
 begin
   // this callback is called only once
   result := paAbort;