--- /dev/null
+++ b/PsychSourceGL/Cohorts/PortAudio/patches/common_timeinfo_currenttime
@@ -0,0 +1,15 @@
+From: Mario Kleiner <mario.kleiner@tuebingen.mpg.de>
+Subject: disable resetting of timeInfo->currentTime
+Origin: PTB-3
+
+--- a/portaudio/src/common/pa_process.c
++++ b/portaudio/src/common/pa_process.c
+@@ -683,7 +683,7 @@ void PaUtil_BeginBufferProcessing( PaUti
+         
+     bp->timeInfo->inputBufferAdcTime -= bp->framesInTempInputBuffer * bp->samplePeriod;
+     
+-    bp->timeInfo->currentTime = 0; /** FIXME: @todo time info currentTime not implemented */
++    // MARIO MK CHANGED PTB: bp->timeInfo->currentTime = 0; /** FIXME: @todo time info currentTime not implemented */
+ 
+     /* the first streamCallback will be called to generate samples which will be
+         outputted after the frames currently in the output buffer have been
--- /dev/null
+++ b/PsychSourceGL/Cohorts/PortAudio/patches/common_unique_DebugPrint
@@ -0,0 +1,36 @@
+From: Mario Kleiner <mario.kleiner@tuebingen.mpg.de>
+Subject: avoid PaUtil_DebugPrint defined in multiple locations -- reuse pa_debugprint.o
+Origin: PTB-3
+
+
+--- a/portaudio/Makefile.in
++++ b/portaudio/Makefile.in
+@@ -49,6 +49,7 @@ COMMON_OBJS = \
+ 	src/common/pa_cpuload.o \
+ 	src/common/pa_dither.o \
+ 	src/common/pa_front.o \
++	src/common/pa_debugprint.o \
+ 	src/common/pa_process.o \
+ 	src/common/pa_skeleton.o \
+ 	src/common/pa_stream.o \
+--- a/portaudio/src/common/pa_front.c
++++ b/portaudio/src/common/pa_front.c
+@@ -158,7 +158,8 @@ void PaUtil_SetLastHostErrorInfo( PaHost
+     strncpy( lastHostErrorText_, errorText, PA_LAST_HOST_ERROR_TEXT_LENGTH_ );
+ }
+ 
+-
++/*
++MK CHANGED PTB - Already defined in pa_debugprint
+ void PaUtil_DebugPrint( const char *format, ... )
+ {
+     va_list ap;
+@@ -169,7 +170,7 @@ void PaUtil_DebugPrint( const char *form
+ 
+     fflush( stderr );
+ }
+-
++*/
+ 
+ static PaUtilHostApiRepresentation **hostApis_ = 0;
+ static int hostApisCount_ = 0;
--- /dev/null
+++ b/PsychSourceGL/Cohorts/PortAudio/patches/linux_sched_rt
@@ -0,0 +1,58 @@
+From: Mario Kleiner <mario.kleiner@tuebingen.mpg.de>
+Subject: enforce (when possible) SCHED_RR on Linux systems
+Origin: PTB-3
+
+
+
+--- a/portaudio/src/os/unix/pa_unix_util.c
++++ b/portaudio/src/os/unix/pa_unix_util.c
+@@ -224,9 +224,18 @@ PaError PaUnixThread_Initialize( PaUnixT
+ }
+ #endif
+ 
++// MK: Enable Psychtoolbox specific Realtime scheduling setup code for RT scheduling the audio callback thread.
++#define MK_PSYCH_RTSCHED 1
++
+ PaError PaUnixThread_New( PaUnixThread* self, void* (*threadFunc)( void* ), void* threadArg, PaTime waitForChild )
+ {
+-    PaError result = paNoError;
++#ifdef MK_PSYCH_RTSCHED
++	// MK: New code, not in original. Unconditionally try to boost callback threads priority
++	// to RT_FIFO realtime scheduling with given realtime priority. See below for rest.
++    struct sched_param spm = { 0 };
++	int policy;
++#endif 
++	PaError result = paNoError;
+     pthread_attr_t attr;
+     int started = 0;
+ 
+@@ -260,6 +269,29 @@ PaError PaUnixThread_New( PaUnixThread*
+     PA_UNLESS( !pthread_create( &self->thread, &attr, threadFunc, threadArg ), paInternalError );
+     started = 1;
+ 
++#ifdef MK_PSYCH_RTSCHED
++	// MK: New code, not in original. Unconditionally try to boost callback threads priority
++	// to RT_FIFO realtime scheduling with given realtime priority.
++	
++	// Query parent threads policy and priority:
++	pthread_getschedparam(pthread_self(), &policy, &spm);
++	
++	// If not RT policy, assign a base priority of minimum SCHED_FIFO. Otherwise use RT priority of parent as baseline:
++	if ((policy != SCHED_FIFO ) && (policy != SCHED_RR)) spm.sched_priority = sched_get_priority_min( SCHED_FIFO );
++	
++	// Set audio callback threads RT priority to parents baseline + 4, so it gets quite a boost wrt. its parent.
++	// Clamp to allowable maximum though:
++    spm.sched_priority = PA_MIN( spm.sched_priority + 4 , sched_get_priority_max( SCHED_FIFO ) );
++	
++	// Try to switch callback thread to SCHED_FIFO Realtime scheduling with proper realtime priority,
++	// but don't be pissed if it doesn't work. No all too big deal:
++    if( pthread_setschedparam(self->thread, SCHED_FIFO, &spm) != 0 )
++    {
++        PA_DEBUG(( "WARNING: Failed bumping audio callback thread to realtime priority!\n" ));
++    }
++
++#endif
++
+ #if 0
+     if( th->rtSched )
+     {
--- /dev/null
+++ b/PsychSourceGL/Cohorts/PortAudio/patches/series
@@ -0,0 +1,4 @@
+common_unique_DebugPrint
+common_timeinfo_currenttime
+linux_sched_rt
+dither_amd64_fixes
--- /dev/null
+++ b/PsychSourceGL/Cohorts/PortAudio/patches/dither_amd64_fixes
@@ -0,0 +1,124 @@
+--- a/portaudio/src/common/pa_dither.c
++++ b/portaudio/src/common/pa_dither.c
+@@ -1,5 +1,5 @@
+ /*
+- * $Id: pa_dither.c 1097 2006-08-26 08:27:53Z rossb $
++ * $Id$
+  * Portable Audio I/O Library triangular dither generator
+  *
+  * Based on the Open Source API proposed by Ross Bencina
+@@ -42,9 +42,14 @@
+  @brief Functions for generating dither noise
+ */
+ 
+-
+-#include "pa_dither.h"
+ #include "pa_types.h"
++#include "pa_dither.h"
++
++
++/* Note that the linear congruential algorithm requires 32 bit integers
++ * because it uses arithmetic overflow. So use PaUint32 instead of
++ * unsigned long so it will work on 64 bit systems.
++ */
+ 
+ #define PA_DITHER_BITS_   (15)
+ 
+@@ -57,9 +62,9 @@ void PaUtil_InitializeTriangularDitherSt
+ }
+ 
+ 
+-signed long PaUtil_Generate16BitTriangularDither( PaUtilTriangularDitherGenerator *state )
++PaInt32 PaUtil_Generate16BitTriangularDither( PaUtilTriangularDitherGenerator *state )
+ {
+-    signed long current, highPass;
++    PaInt32 current, highPass;
+ 
+     /* Generate two random numbers. */
+     state->randSeed1 = (state->randSeed1 * 196314165) + 907633515;
+@@ -69,9 +74,10 @@ signed long PaUtil_Generate16BitTriangul
+      * Shift before adding to prevent overflow which would skew the distribution.
+      * Also shift an extra bit for the high pass filter. 
+      */
+-#define DITHER_SHIFT_  ((SIZEOF_LONG*8 - PA_DITHER_BITS_) + 1)
+-    current = (((signed long)state->randSeed1)>>DITHER_SHIFT_) +
+-              (((signed long)state->randSeed2)>>DITHER_SHIFT_);
++#define DITHER_SHIFT_  ((sizeof(PaInt32)*8 - PA_DITHER_BITS_) + 1)
++	
++    current = (((PaInt32)state->randSeed1)>>DITHER_SHIFT_) +
++              (((PaInt32)state->randSeed2)>>DITHER_SHIFT_);
+ 
+     /* High pass filter to reduce audibility. */
+     highPass = current - state->previous;
+@@ -86,7 +92,7 @@ static const float const_float_dither_sc
+ 
+ float PaUtil_GenerateFloatTriangularDither( PaUtilTriangularDitherGenerator *state )
+ {
+-    signed long current, highPass;
++    PaInt32 current, highPass;
+ 
+     /* Generate two random numbers. */
+     state->randSeed1 = (state->randSeed1 * 196314165) + 907633515;
+@@ -96,9 +102,8 @@ float PaUtil_GenerateFloatTriangularDith
+      * Shift before adding to prevent overflow which would skew the distribution.
+      * Also shift an extra bit for the high pass filter. 
+      */
+-#define DITHER_SHIFT_  ((SIZEOF_LONG*8 - PA_DITHER_BITS_) + 1)
+-    current = (((signed long)state->randSeed1)>>DITHER_SHIFT_) +
+-              (((signed long)state->randSeed2)>>DITHER_SHIFT_);
++    current = (((PaInt32)state->randSeed1)>>DITHER_SHIFT_) +
++              (((PaInt32)state->randSeed2)>>DITHER_SHIFT_);
+ 
+     /* High pass filter to reduce audibility. */
+     highPass = current - state->previous;
+--- a/portaudio/src/common/pa_dither.h
++++ b/portaudio/src/common/pa_dither.h
+@@ -1,7 +1,7 @@
+ #ifndef PA_DITHER_H
+ #define PA_DITHER_H
+ /*
+- * $Id: pa_dither.h 1097 2006-08-26 08:27:53Z rossb $
++ * $Id$
+  * Portable Audio I/O Library triangular dither generator
+  *
+  * Based on the Open Source API proposed by Ross Bencina
+@@ -44,18 +44,24 @@
+  @brief Functions for generating dither noise
+ */
+ 
++#include "pa_types.h"
++
+ 
+ #ifdef __cplusplus
+ extern "C"
+ {
+ #endif /* __cplusplus */
+ 
++/* Note that the linear congruential algorithm requires 32 bit integers
++ * because it uses arithmetic overflow. So use PaUint32 instead of
++ * unsigned long so it will work on 64 bit systems.
++ */
+ 
+ /** @brief State needed to generate a dither signal */
+ typedef struct PaUtilTriangularDitherGenerator{
+-    unsigned long previous;
+-    unsigned long randSeed1;
+-    unsigned long randSeed2;
++    PaUint32 previous;
++    PaUint32 randSeed1;
++    PaUint32 randSeed2;
+ } PaUtilTriangularDitherGenerator;
+ 
+ 
+@@ -73,9 +79,9 @@ void PaUtil_InitializeTriangularDitherSt
+     signed short out = (signed short)(((in>>1) + dither) >> 15);
+ </pre>
+  @return
+- A signed long with a range of +32767 to -32768
++ A signed 32-bit integer with a range of +32767 to -32768
+ */
+-signed long PaUtil_Generate16BitTriangularDither( PaUtilTriangularDitherGenerator *ditherState );
++PaInt32 PaUtil_Generate16BitTriangularDither( PaUtilTriangularDitherGenerator *ditherState );
+ 
+ 
+ /**