add initial structure

1 files changed, 2052 insertions, 0 deletions

diff --git a/portaudio/src/hostapi/oss/pa_unix_oss.c b/portaudio/src/hostapi/oss/pa_unix_oss.c
new file mode 100644
index 0000000..20113e2
--- /dev/null
+++ b/portaudio/src/hostapi/oss/pa_unix_oss.c
@@ -0,0 +1,2052 @@
+/*
+ * $Id$
+ * PortAudio Portable Real-Time Audio Library
+ * Latest Version at: http://www.portaudio.com
+ * OSS implementation by:
+ *   Douglas Repetto
+ *   Phil Burk
+ *   Dominic Mazzoni
+ *   Arve Knudsen
+ *
+ * Based on the Open Source API proposed by Ross Bencina
+ * Copyright (c) 1999-2002 Ross Bencina, Phil Burk
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
+ * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+/*
+ * The text above constitutes the entire PortAudio license; however,
+ * the PortAudio community also makes the following non-binding requests:
+ *
+ * Any person wishing to distribute modifications to the Software is
+ * requested to send the modifications to the original developer so that
+ * they can be incorporated into the canonical version. It is also
+ * requested that these non-binding requests be included along with the
+ * license above.
+ */
+
+/**
+ @file
+ @ingroup hostapi_src
+*/
+
+#include <stdio.h>
+#include <string.h>
+#include <math.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/poll.h>
+#include <limits.h>
+#include <semaphore.h>
+
+#ifdef HAVE_SYS_SOUNDCARD_H
+# include <sys/soundcard.h>
+# ifdef __NetBSD__
+#  define DEVICE_NAME_BASE           "/dev/audio"
+# else
+#  define DEVICE_NAME_BASE           "/dev/dsp"
+# endif
+#elif defined(HAVE_LINUX_SOUNDCARD_H)
+# include <linux/soundcard.h>
+# define DEVICE_NAME_BASE            "/dev/dsp"
+#elif defined(HAVE_MACHINE_SOUNDCARD_H)
+# include <machine/soundcard.h> /* JH20010905 */
+# define DEVICE_NAME_BASE            "/dev/audio"
+#else
+# error No sound card header file
+#endif
+
+#include "portaudio.h"
+#include "pa_util.h"
+#include "pa_allocation.h"
+#include "pa_hostapi.h"
+#include "pa_stream.h"
+#include "pa_cpuload.h"
+#include "pa_process.h"
+#include "pa_unix_util.h"
+#include "pa_debugprint.h"
+
+static int sysErr_;
+static pthread_t mainThread_;
+
+/* Check return value of system call, and map it to PaError */
+#define ENSURE_(expr, code) \
+    do { \
+        if( UNLIKELY( (sysErr_ = (expr)) < 0 ) ) \
+        { \
+            /* PaUtil_SetLastHostErrorInfo should only be used in the main thread */ \
+            if( (code) == paUnanticipatedHostError && pthread_self() == mainThread_ ) \
+            { \
+                PaUtil_SetLastHostErrorInfo( paOSS, sysErr_, strerror( errno ) ); \
+            } \
+            \
+            PaUtil_DebugPrint(( "Expression '" #expr "' failed in '" __FILE__ "', line: " STRINGIZE( __LINE__ ) "\n" )); \
+            result = (code); \
+            goto error; \
+        } \
+    } while( 0 );
+
+#ifndef AFMT_S16_NE
+#define AFMT_S16_NE  Get_AFMT_S16_NE()
+/*********************************************************************
+ * Some versions of OSS do not define AFMT_S16_NE. So check CPU.
+ * PowerPC is Big Endian. X86 is Little Endian.
+ */
+static int Get_AFMT_S16_NE( void )
+{
+    long testData = 1;
+    char *ptr = (char *) &testData;
+    int isLittle = ( *ptr == 1 ); /* Does address point to least significant byte? */
+    return isLittle ? AFMT_S16_LE : AFMT_S16_BE;
+}
+#endif
+
+/* PaOSSHostApiRepresentation - host api datastructure specific to this implementation */
+
+typedef struct
+{
+    PaUtilHostApiRepresentation inheritedHostApiRep;
+    PaUtilStreamInterface callbackStreamInterface;
+    PaUtilStreamInterface blockingStreamInterface;
+
+    PaUtilAllocationGroup *allocations;
+
+    PaHostApiIndex hostApiIndex;
+}
+PaOSSHostApiRepresentation;
+
+/** Per-direction structure for PaOssStream.
+ *
+ * Aspect StreamChannels: In case the user requests to open the same device for both capture and playback,
+ * but with different number of channels we will have to adapt between the number of user and host
+ * channels for at least one direction, since the configuration space is the same for both directions
+ * of an OSS device.
+ */
+typedef struct
+{
+    int fd;
+    const char *devName;
+    int userChannelCount, hostChannelCount;
+    int userInterleaved;
+    void *buffer;
+    PaSampleFormat userFormat, hostFormat;
+    double latency;
+    unsigned long hostFrames, numBufs;
+    void **userBuffers; /* For non-interleaved blocking */
+} PaOssStreamComponent;
+
+/** Implementation specific representation of a PaStream.
+ *
+ */
+typedef struct PaOssStream
+{
+    PaUtilStreamRepresentation streamRepresentation;
+    PaUtilCpuLoadMeasurer cpuLoadMeasurer;
+    PaUtilBufferProcessor bufferProcessor;
+
+    PaUtilThreading threading;
+
+    int sharedDevice;
+    unsigned long framesPerHostBuffer;
+    int triggered;  /* Have the devices been triggered yet (first start) */
+
+    int isActive;
+    int isStopped;
+
+    int lastPosPtr;
+    double lastStreamBytes;
+
+    int framesProcessed;
+
+    double sampleRate;
+
+    int callbackMode;
+    volatile int callbackStop, callbackAbort;
+
+    PaOssStreamComponent *capture, *playback;
+    unsigned long pollTimeout;
+    sem_t semaphore;
+}
+PaOssStream;
+
+typedef enum {
+    StreamMode_In,
+    StreamMode_Out
+} StreamMode;
+
+/* prototypes for functions declared in this file */
+
+static void Terminate( struct PaUtilHostApiRepresentation *hostApi );
+static PaError IsFormatSupported( struct PaUtilHostApiRepresentation *hostApi,
+                                  const PaStreamParameters *inputParameters,
+                                  const PaStreamParameters *outputParameters,
+                                  double sampleRate );
+static PaError OpenStream( struct PaUtilHostApiRepresentation *hostApi,
+                           PaStream** s,
+                           const PaStreamParameters *inputParameters,
+                           const PaStreamParameters *outputParameters,
+                           double sampleRate,
+                           unsigned long framesPerBuffer,
+                           PaStreamFlags streamFlags,
+                           PaStreamCallback *streamCallback,
+                           void *userData );
+static PaError CloseStream( PaStream* stream );
+static PaError StartStream( PaStream *stream );
+static PaError StopStream( PaStream *stream );
+static PaError AbortStream( PaStream *stream );
+static PaError IsStreamStopped( PaStream *s );
+static PaError IsStreamActive( PaStream *stream );
+static PaTime GetStreamTime( PaStream *stream );
+static double GetStreamCpuLoad( PaStream* stream );
+static PaError ReadStream( PaStream* stream, void *buffer, unsigned long frames );
+static PaError WriteStream( PaStream* stream, const void *buffer, unsigned long frames );
+static signed long GetStreamReadAvailable( PaStream* stream );
+static signed long GetStreamWriteAvailable( PaStream* stream );
+static PaError BuildDeviceList( PaOSSHostApiRepresentation *hostApi );
+
+
+/** Initialize the OSS API implementation.
+ *
+ * This function will initialize host API datastructures and query host devices for information.
+ *
+ * Aspect DeviceCapabilities: Enumeration of host API devices is initiated from here
+ *
+ * Aspect FreeResources: If an error is encountered under way we have to free each resource allocated in this function,
+ * this happens with the usual "error" label.
+ */
+PaError PaOSS_Initialize( PaUtilHostApiRepresentation **hostApi, PaHostApiIndex hostApiIndex )
+{
+    PaError result = paNoError;
+    PaOSSHostApiRepresentation *ossHostApi = NULL;
+
+    PA_UNLESS( ossHostApi = (PaOSSHostApiRepresentation*)PaUtil_AllocateMemory( sizeof(PaOSSHostApiRepresentation) ),
+            paInsufficientMemory );
+    PA_UNLESS( ossHostApi->allocations = PaUtil_CreateAllocationGroup(), paInsufficientMemory );
+    ossHostApi->hostApiIndex = hostApiIndex;
+
+    /* Initialize host API structure */
+    *hostApi = &ossHostApi->inheritedHostApiRep;
+    (*hostApi)->info.structVersion = 1;
+    (*hostApi)->info.type = paOSS;
+    (*hostApi)->info.name = "OSS";
+    (*hostApi)->Terminate = Terminate;
+    (*hostApi)->OpenStream = OpenStream;
+    (*hostApi)->IsFormatSupported = IsFormatSupported;
+
+    PA_ENSURE( BuildDeviceList( ossHostApi ) );
+
+    PaUtil_InitializeStreamInterface( &ossHostApi->callbackStreamInterface, CloseStream, StartStream,
+                                      StopStream, AbortStream, IsStreamStopped, IsStreamActive,
+                                      GetStreamTime, GetStreamCpuLoad,
+                                      PaUtil_DummyRead, PaUtil_DummyWrite,
+                                      PaUtil_DummyGetReadAvailable,
+                                      PaUtil_DummyGetWriteAvailable );
+
+    PaUtil_InitializeStreamInterface( &ossHostApi->blockingStreamInterface, CloseStream, StartStream,
+                                      StopStream, AbortStream, IsStreamStopped, IsStreamActive,
+                                      GetStreamTime, PaUtil_DummyGetCpuLoad,
+                                      ReadStream, WriteStream, GetStreamReadAvailable, GetStreamWriteAvailable );
+
+    mainThread_ = pthread_self();
+
+    return result;
+
+error:
+    if( ossHostApi )
+    {
+        if( ossHostApi->allocations )
+        {
+            PaUtil_FreeAllAllocations( ossHostApi->allocations );
+            PaUtil_DestroyAllocationGroup( ossHostApi->allocations );
+        }
+
+        PaUtil_FreeMemory( ossHostApi );
+    }
+    return result;
+}
+
+PaError PaUtil_InitializeDeviceInfo( PaDeviceInfo *deviceInfo, const char *name, PaHostApiIndex hostApiIndex, int maxInputChannels,
+        int maxOutputChannels, PaTime defaultLowInputLatency, PaTime defaultLowOutputLatency, PaTime defaultHighInputLatency,
+        PaTime defaultHighOutputLatency, double defaultSampleRate, PaUtilAllocationGroup *allocations  )
+{
+    PaError result = paNoError;
+
+    deviceInfo->structVersion = 2;
+    if( allocations )
+    {
+        size_t len = strlen( name ) + 1;
+        PA_UNLESS( deviceInfo->name = PaUtil_GroupAllocateMemory( allocations, len ), paInsufficientMemory );
+        strncpy( (char *)deviceInfo->name, name, len );
+    }
+    else
+        deviceInfo->name = name;
+
+    deviceInfo->hostApi = hostApiIndex;
+    deviceInfo->maxInputChannels = maxInputChannels;
+    deviceInfo->maxOutputChannels = maxOutputChannels;
+    deviceInfo->defaultLowInputLatency = defaultLowInputLatency;
+    deviceInfo->defaultLowOutputLatency = defaultLowOutputLatency;
+    deviceInfo->defaultHighInputLatency = defaultHighInputLatency;
+    deviceInfo->defaultHighOutputLatency = defaultHighOutputLatency;
+    deviceInfo->defaultSampleRate = defaultSampleRate;
+
+error:
+    return result;
+}
+
+static int CalcHigherLogTwo( int n )
+{
+    int log2 = 0;
+    while( (1<<log2) < n ) log2++;
+    return log2;
+}
+
+static PaError QueryDirection( const char *deviceName, StreamMode mode, double *defaultSampleRate, int *maxChannelCount,
+        double *defaultLowLatency, double *defaultHighLatency )
+{
+    PaError result = paNoError;
+    int numChannels, maxNumChannels;
+    int busy = 0;
+    int devHandle = -1;
+    int sr;
+    *maxChannelCount = 0;  /* Default value in case this fails */
+    int temp, frgmt;
+    unsigned long fragFrames;
+
+    if ( (devHandle = open( deviceName, (mode == StreamMode_In ? O_RDONLY : O_WRONLY) | O_NONBLOCK ))  < 0 )
+    {
+        if( errno == EBUSY || errno == EAGAIN )
+        {
+            PA_DEBUG(( "%s: Device %s busy\n", __FUNCTION__, deviceName ));
+        }
+        else
+        {
+            /* Ignore ENOENT, which means we've tried a non-existent device */
+            if( errno != ENOENT )
+            {
+                PA_DEBUG(( "%s: Can't access device %s: %s\n", __FUNCTION__, deviceName, strerror( errno ) ));
+            }
+        }
+
+        return paDeviceUnavailable;
+    }
+
+    /* Negotiate for the maximum number of channels for this device. PLB20010927
+     * Consider up to 16 as the upper number of channels.
+     * Variable maxNumChannels should contain the actual upper limit after the call.
+     * Thanks to John Lazzaro and Heiko Purnhagen for suggestions.
+     */
+    maxNumChannels = 0;
+    for( numChannels = 1; numChannels <= 16; numChannels++ )
+    {
+        temp = numChannels;
+        if( ioctl( devHandle, SNDCTL_DSP_CHANNELS, &temp ) < 0 )
+        {
+            busy = EAGAIN == errno || EBUSY == errno;
+            /* ioctl() failed so bail out if we already have stereo */
+            if( maxNumChannels >= 2 )
+                break;
+        }
+        else
+        {
+            /* ioctl() worked but bail out if it does not support numChannels.
+             * We don't want to leave gaps in the numChannels supported.
+             */
+            if( (numChannels > 2) && (temp != numChannels) )
+                break;
+            if( temp > maxNumChannels )
+                maxNumChannels = temp; /* Save maximum. */
+        }
+    }
+    /* A: We're able to open a device for capture if it's busy playing back and vice versa,
+     * but we can't configure anything */
+    if( 0 == maxNumChannels && busy )
+    {
+        result = paDeviceUnavailable;
+        goto error;
+    }
+
+    /* The above negotiation may fail for an old driver so try this older technique. */
+    if( maxNumChannels < 1 )
+    {
+        int stereo = 1;
+        if( ioctl( devHandle, SNDCTL_DSP_STEREO, &stereo ) < 0 )
+        {
+            maxNumChannels = 1;
+        }
+        else
+        {
+            maxNumChannels = (stereo) ? 2 : 1;
+        }
+        PA_DEBUG(( "%s: use SNDCTL_DSP_STEREO, maxNumChannels = %d\n", __FUNCTION__, maxNumChannels ));
+    }
+
+    /* During channel negotiation, the last ioctl() may have failed. This can
+     * also cause sample rate negotiation to fail. Hence the following, to return
+     * to a supported number of channels. SG20011005 */
+    {
+        /* use most reasonable default value */
+        numChannels = PA_MIN( maxNumChannels, 2 );
+        ENSURE_( ioctl( devHandle, SNDCTL_DSP_CHANNELS, &numChannels ), paUnanticipatedHostError );
+    }
+
+    /* Get supported sample rate closest to 44100 Hz */
+    if( *defaultSampleRate < 0 )
+    {
+        sr = 44100;
+        ENSURE_( ioctl( devHandle, SNDCTL_DSP_SPEED, &sr ), paUnanticipatedHostError );
+
+        *defaultSampleRate = sr;
+    }
+
+    *maxChannelCount = maxNumChannels;
+
+    /* Attempt to set low latency with 4 frags-per-buffer, 128 frames-per-frag (total buffer 512 frames)
+     * since the ioctl sets bytes, multiply by numChannels, and base on 2 bytes-per-sample, */
+    fragFrames = 128;
+    frgmt = (4 << 16) + (CalcHigherLogTwo( fragFrames * numChannels * 2 ) & 0xffff);
+    ENSURE_( ioctl( devHandle, SNDCTL_DSP_SETFRAGMENT, &frgmt ), paUnanticipatedHostError );
+
+    /* Use the value set by the ioctl to give the latency achieved */
+    fragFrames = pow( 2, frgmt & 0xffff ) / (numChannels * 2);
+    *defaultLowLatency = ((frgmt >> 16) - 1) * fragFrames / *defaultSampleRate;
+
+    /* Cannot now try setting a high latency (device would need closing and opening again).  Make
+     * high-latency 4 times the low unless the fragFrames are significantly more than requested 128 */
+    temp = (fragFrames < 256) ? 4 : (fragFrames < 512) ? 2 : 1;
+    *defaultHighLatency = temp * *defaultLowLatency;
+
+error:
+    if( devHandle >= 0 )
+        close( devHandle );
+
+    return result;
+}
+
+/** Query OSS device.
+ *
+ * This is where PaDeviceInfo objects are constructed and filled in with relevant information.
+ *
+ * Aspect DeviceCapabilities: The inferred device capabilities are recorded in a PaDeviceInfo object that is constructed
+ * in place.
+ */
+static PaError QueryDevice( char *deviceName, PaOSSHostApiRepresentation *ossApi, PaDeviceInfo **deviceInfo )
+{
+    PaError result = paNoError;
+    double sampleRate = -1.;
+    int maxInputChannels, maxOutputChannels;
+    PaTime defaultLowInputLatency, defaultLowOutputLatency, defaultHighInputLatency, defaultHighOutputLatency;
+    PaError tmpRes = paNoError;
+    int busy = 0;
+    *deviceInfo = NULL;
+
+    /* douglas:
+       we have to do this querying in a slightly different order. apparently
+       some sound cards will give you different info based on their settings.
+       e.g. a card might give you stereo at 22kHz but only mono at 44kHz.
+       the correct order for OSS is: format, channels, sample rate
+    */
+
+    /* Aspect StreamChannels: The number of channels supported for a device may depend on the mode it is
+     * opened in, it may have more channels available for capture than playback and vice versa. Therefore
+     * we will open the device in both read- and write-only mode to determine the supported number.
+     */
+    if( (tmpRes = QueryDirection( deviceName, StreamMode_In, &sampleRate, &maxInputChannels, &defaultLowInputLatency,
+                &defaultHighInputLatency )) != paNoError )
+    {
+        if( tmpRes != paDeviceUnavailable )
+        {
+            PA_DEBUG(( "%s: Querying device %s for capture failed!\n", __FUNCTION__, deviceName ));
+            /* PA_ENSURE( tmpRes ); */
+        }
+        ++busy;
+    }
+    if( (tmpRes = QueryDirection( deviceName, StreamMode_Out, &sampleRate, &maxOutputChannels, &defaultLowOutputLatency,
+                &defaultHighOutputLatency )) != paNoError )
+    {
+        if( tmpRes != paDeviceUnavailable )
+        {
+            PA_DEBUG(( "%s: Querying device %s for playback failed!\n", __FUNCTION__, deviceName ));
+            /* PA_ENSURE( tmpRes ); */
+        }
+        ++busy;
+    }
+    assert( 0 <= busy && busy <= 2 );
+    if( 2 == busy )     /* Both directions are unavailable to us */
+    {
+        result = paDeviceUnavailable;
+        goto error;
+    }
+
+    PA_UNLESS( *deviceInfo = PaUtil_GroupAllocateMemory( ossApi->allocations, sizeof (PaDeviceInfo) ), paInsufficientMemory );
+    PA_ENSURE( PaUtil_InitializeDeviceInfo( *deviceInfo, deviceName, ossApi->hostApiIndex, maxInputChannels, maxOutputChannels,
+                defaultLowInputLatency, defaultLowOutputLatency, defaultHighInputLatency, defaultHighOutputLatency, sampleRate,
+                ossApi->allocations ) );
+
+error:
+    return result;
+}
+
+/** Query host devices.
+ *
+ * Loop over host devices and query their capabilitiesu
+ *
+ * Aspect DeviceCapabilities: This function calls QueryDevice on each device entry and receives a filled in PaDeviceInfo object
+ * per device, these are placed in the host api representation's deviceInfos array.
+ */
+static PaError BuildDeviceList( PaOSSHostApiRepresentation *ossApi )
+{
+    PaError result = paNoError;
+    PaUtilHostApiRepresentation *commonApi = &ossApi->inheritedHostApiRep;
+    int i;
+    int numDevices = 0, maxDeviceInfos = 1;
+    PaDeviceInfo **deviceInfos = NULL;
+
+    /* These two will be set to the first working input and output device, respectively */
+    commonApi->info.defaultInputDevice = paNoDevice;
+    commonApi->info.defaultOutputDevice = paNoDevice;
+
+    /* Find devices by calling QueryDevice on each
+     * potential device names.  When we find a valid one,
+     * add it to a linked list.
+     * A: Set an arbitrary of 100 devices, should probably be a smarter way. */
+
+    for( i = -1; i < 100; i++ )
+    {
+        char deviceName[32];
+        PaDeviceInfo *deviceInfo;
+        int testResult;
+
+        if( i == -1 )
+            snprintf(deviceName, sizeof (deviceName), "%s", DEVICE_NAME_BASE);
+        else
+            snprintf(deviceName, sizeof (deviceName), "%s%d", DEVICE_NAME_BASE, i);
+
+        /* PA_DEBUG(("%s: trying device %s\n", __FUNCTION__, deviceName )); */
+        if( (testResult = QueryDevice( deviceName, ossApi, &deviceInfo )) != paNoError )
+        {
+            if( testResult != paDeviceUnavailable )
+                PA_ENSURE( testResult );
+
+            continue;
+        }
+
+        ++numDevices;
+        if( !deviceInfos || numDevices > maxDeviceInfos )
+        {
+            maxDeviceInfos *= 2;
+            PA_UNLESS( deviceInfos = (PaDeviceInfo **) realloc( deviceInfos, maxDeviceInfos * sizeof (PaDeviceInfo *) ),
+                    paInsufficientMemory );
+        }
+        {
+            int devIdx = numDevices - 1;
+            deviceInfos[devIdx] = deviceInfo;
+
+            if( commonApi->info.defaultInputDevice == paNoDevice && deviceInfo->maxInputChannels > 0 )
+                commonApi->info.defaultInputDevice = devIdx;
+            if( commonApi->info.defaultOutputDevice == paNoDevice && deviceInfo->maxOutputChannels > 0 )
+                commonApi->info.defaultOutputDevice = devIdx;
+        }
+    }
+
+    /* Make an array of PaDeviceInfo pointers out of the linked list */
+
+    PA_DEBUG(("PaOSS %s: Total number of devices found: %d\n", __FUNCTION__, numDevices));
+
+    commonApi->deviceInfos = (PaDeviceInfo**)PaUtil_GroupAllocateMemory(
+        ossApi->allocations, sizeof(PaDeviceInfo*) * numDevices );
+    memcpy( commonApi->deviceInfos, deviceInfos, numDevices * sizeof (PaDeviceInfo *) );
+
+    commonApi->info.deviceCount = numDevices;
+
+error:
+    free( deviceInfos );
+
+    return result;
+}
+
+static void Terminate( struct PaUtilHostApiRepresentation *hostApi )
+{
+    PaOSSHostApiRepresentation *ossHostApi = (PaOSSHostApiRepresentation*)hostApi;
+
+    if( ossHostApi->allocations )
+    {
+        PaUtil_FreeAllAllocations( ossHostApi->allocations );
+        PaUtil_DestroyAllocationGroup( ossHostApi->allocations );
+    }
+
+    PaUtil_FreeMemory( ossHostApi );
+}
+
+static PaError IsFormatSupported( struct PaUtilHostApiRepresentation *hostApi,
+                                  const PaStreamParameters *inputParameters,
+                                  const PaStreamParameters *outputParameters,
+                                  double sampleRate )
+{
+    PaError result = paNoError;
+    PaDeviceIndex device;
+    PaDeviceInfo *deviceInfo;
+    char *deviceName;
+    int inputChannelCount, outputChannelCount;
+    int tempDevHandle = -1;
+    int flags;
+    PaSampleFormat inputSampleFormat, outputSampleFormat;
+
+    if( inputParameters )
+    {
+        inputChannelCount = inputParameters->channelCount;
+        inputSampleFormat = inputParameters->sampleFormat;
+
+        /* unless alternate device specification is supported, reject the use of
+            paUseHostApiSpecificDeviceSpecification */
+
+        if( inputParameters->device == paUseHostApiSpecificDeviceSpecification )
+            return paInvalidDevice;
+
+        /* check that input device can support inputChannelCount */
+        if( inputChannelCount > hostApi->deviceInfos[ inputParameters->device ]->maxInputChannels )
+            return paInvalidChannelCount;
+
+        /* validate inputStreamInfo */
+        if( inputParameters->hostApiSpecificStreamInfo )
+            return paIncompatibleHostApiSpecificStreamInfo; /* this implementation doesn't use custom stream info */
+    }
+    else
+    {
+        inputChannelCount = 0;
+    }
+
+    if( outputParameters )
+    {
+        outputChannelCount = outputParameters->channelCount;
+        outputSampleFormat = outputParameters->sampleFormat;
+
+        /* unless alternate device specification is supported, reject the use of
+            paUseHostApiSpecificDeviceSpecification */
+
+        if( outputParameters->device == paUseHostApiSpecificDeviceSpecification )
+            return paInvalidDevice;
+
+        /* check that output device can support inputChannelCount */
+        if( outputChannelCount > hostApi->deviceInfos[ outputParameters->device ]->maxOutputChannels )
+            return paInvalidChannelCount;
+
+        /* validate outputStreamInfo */
+        if( outputParameters->hostApiSpecificStreamInfo )
+            return paIncompatibleHostApiSpecificStreamInfo; /* this implementation doesn't use custom stream info */
+    }
+    else
+    {
+        outputChannelCount = 0;
+    }
+
+    if (inputChannelCount == 0 && outputChannelCount == 0)
+        return paInvalidChannelCount;
+
+    /* if full duplex, make sure that they're the same device */
+
+    if (inputChannelCount > 0 && outputChannelCount > 0 &&
+            inputParameters->device != outputParameters->device)
+        return paInvalidDevice;
+
+    /* if full duplex, also make sure that they're the same number of channels */
+
+    if (inputChannelCount > 0 && outputChannelCount > 0 &&
+            inputChannelCount != outputChannelCount)
+        return paInvalidChannelCount;
+
+    /* open the device so we can do more tests */
+
+    if( inputChannelCount > 0 )
+    {
+        result = PaUtil_DeviceIndexToHostApiDeviceIndex(&device, inputParameters->device, hostApi);
+        if (result != paNoError)
+            return result;
+    }
+    else
+    {
+        result = PaUtil_DeviceIndexToHostApiDeviceIndex(&device, outputParameters->device, hostApi);
+        if (result != paNoError)
+            return result;
+    }
+
+    deviceInfo = hostApi->deviceInfos[device];
+    deviceName = (char *)deviceInfo->name;
+
+    flags = O_NONBLOCK;
+    if (inputChannelCount > 0 && outputChannelCount > 0)
+        flags |= O_RDWR;
+    else if (inputChannelCount > 0)
+        flags |= O_RDONLY;
+    else
+        flags |= O_WRONLY;
+
+    ENSURE_( tempDevHandle = open( deviceInfo->name, flags ), paDeviceUnavailable );
+
+    /* PaOssStream_Configure will do the rest of the checking for us */
+    /* PA_ENSURE( PaOssStream_Configure( tempDevHandle, deviceName, outputChannelCount, &sampleRate ) ); */
+
+    /* everything succeeded! */
+
+error:
+    if( tempDevHandle >= 0 )
+        close( tempDevHandle );
+
+    return result;
+}
+
+/** Validate stream parameters.
+ *
+ * Aspect StreamChannels: We verify that the number of channels is within the allowed range for the device
+ */
+static PaError ValidateParameters( const PaStreamParameters *parameters, const PaDeviceInfo *deviceInfo, StreamMode mode )
+{
+    int maxChans;
+
+    assert( parameters );
+
+    if( parameters->device == paUseHostApiSpecificDeviceSpecification )
+    {
+        return paInvalidDevice;
+    }
+
+    maxChans = (mode == StreamMode_In ? deviceInfo->maxInputChannels : deviceInfo->maxOutputChannels);
+    if( parameters->channelCount > maxChans )
+    {
+        return paInvalidChannelCount;
+    }
+
+    return paNoError;
+}
+
+static PaError PaOssStreamComponent_Initialize( PaOssStreamComponent *component, const PaStreamParameters *parameters,
+        int callbackMode, int fd, const char *deviceName )
+{
+    PaError result = paNoError;
+    assert( component );
+
+    memset( component, 0, sizeof (PaOssStreamComponent) );
+
+    component->fd = fd;
+    component->devName = deviceName;
+    component->userChannelCount = parameters->channelCount;
+    component->userFormat = parameters->sampleFormat;
+    component->latency = parameters->suggestedLatency;
+    component->userInterleaved = !(parameters->sampleFormat & paNonInterleaved);
+
+    if( !callbackMode && !component->userInterleaved )
+    {
+        /* Pre-allocate non-interleaved user provided buffers */
+        PA_UNLESS( component->userBuffers = PaUtil_AllocateMemory( sizeof (void *) * component->userChannelCount ),
+                paInsufficientMemory );
+    }
+
+error:
+    return result;
+}
+
+static void PaOssStreamComponent_Terminate( PaOssStreamComponent *component )
+{
+    assert( component );
+
+    if( component->fd >= 0 )
+        close( component->fd );
+    if( component->buffer )
+        PaUtil_FreeMemory( component->buffer );
+
+    if( component->userBuffers )
+        PaUtil_FreeMemory( component->userBuffers );
+
+    PaUtil_FreeMemory( component );
+}
+
+static PaError ModifyBlocking( int fd, int blocking )
+{
+    PaError result = paNoError;
+    int fflags;
+
+    ENSURE_( fflags = fcntl( fd, F_GETFL ), paUnanticipatedHostError );
+
+    if( blocking )
+        fflags &= ~O_NONBLOCK;
+    else
+        fflags |= O_NONBLOCK;
+
+    ENSURE_( fcntl( fd, F_SETFL, fflags ), paUnanticipatedHostError );
+
+error:
+    return result;
+}
+
+/** Open input and output devices.
+ *
+ * @param idev: Returned input device file descriptor.
+ * @param odev: Returned output device file descriptor.
+ */
+static PaError OpenDevices( const char *idevName, const char *odevName, int *idev, int *odev )
+{
+    PaError result = paNoError;
+    int flags = O_NONBLOCK, duplex = 0;
+    *idev = *odev = -1;
+
+    if( idevName && odevName )
+    {
+        duplex = 1;
+        flags |= O_RDWR;
+    }
+    else if( idevName )
+        flags |= O_RDONLY;
+    else
+        flags |= O_WRONLY;
+
+    /* open first in nonblocking mode, in case it's busy...
+     * A: then unset the non-blocking attribute */
+    assert( flags & O_NONBLOCK );
+    if( idevName )
+    {
+        ENSURE_( *idev = open( idevName, flags ), paDeviceUnavailable );
+        PA_ENSURE( ModifyBlocking( *idev, 1 ) ); /* Blocking */
+    }
+    if( odevName )
+    {
+        if( !idevName )
+        {
+            ENSURE_( *odev = open( odevName, flags ), paDeviceUnavailable );
+            PA_ENSURE( ModifyBlocking( *odev, 1 ) ); /* Blocking */
+        }
+        else
+        {
+            ENSURE_( *odev = dup( *idev ), paUnanticipatedHostError );
+        }
+    }
+
+error:
+    return result;
+}
+
+static PaError PaOssStream_Initialize( PaOssStream *stream, const PaStreamParameters *inputParameters, const PaStreamParameters *outputParameters,
+        PaStreamCallback callback, void *userData, PaStreamFlags streamFlags,
+        PaOSSHostApiRepresentation *ossApi )
+{
+    PaError result = paNoError;
+    int idev, odev;
+    PaUtilHostApiRepresentation *hostApi = &ossApi->inheritedHostApiRep;
+    const char *idevName = NULL, *odevName = NULL;
+
+    assert( stream );
+
+    memset( stream, 0, sizeof (PaOssStream) );
+    stream->isStopped = 1;
+
+    PA_ENSURE( PaUtil_InitializeThreading( &stream->threading ) );
+
+    if( inputParameters && outputParameters )
+    {
+        if( inputParameters->device == outputParameters->device )
+            stream->sharedDevice = 1;
+    }
+
+    if( inputParameters )
+        idevName = hostApi->deviceInfos[inputParameters->device]->name;
+    if( outputParameters )
+        odevName = hostApi->deviceInfos[outputParameters->device]->name;
+    PA_ENSURE( OpenDevices( idevName, odevName, &idev, &odev ) );
+    if( inputParameters )
+    {
+        PA_UNLESS( stream->capture = PaUtil_AllocateMemory( sizeof (PaOssStreamComponent) ), paInsufficientMemory );
+        PA_ENSURE( PaOssStreamComponent_Initialize( stream->capture, inputParameters, callback != NULL, idev, idevName ) );
+    }
+    if( outputParameters )
+    {
+        PA_UNLESS( stream->playback = PaUtil_AllocateMemory( sizeof (PaOssStreamComponent) ), paInsufficientMemory );
+        PA_ENSURE( PaOssStreamComponent_Initialize( stream->playback, outputParameters, callback != NULL, odev, odevName ) );
+    }
+
+    if( callback != NULL )
+    {
+        PaUtil_InitializeStreamRepresentation( &stream->streamRepresentation,
+                                               &ossApi->callbackStreamInterface, callback, userData );
+        stream->callbackMode = 1;
+    }
+    else
+    {
+        PaUtil_InitializeStreamRepresentation( &stream->streamRepresentation,
+                                               &ossApi->blockingStreamInterface, callback, userData );
+    }
+
+    ENSURE_( sem_init( &stream->semaphore, 0, 0 ), paInternalError );
+
+error:
+    return result;
+}
+
+static void PaOssStream_Terminate( PaOssStream *stream )
+{
+    assert( stream );
+
+    PaUtil_TerminateStreamRepresentation( &stream->streamRepresentation );
+    PaUtil_TerminateThreading( &stream->threading );
+
+    if( stream->capture )
+        PaOssStreamComponent_Terminate( stream->capture );
+    if( stream->playback )
+        PaOssStreamComponent_Terminate( stream->playback );
+
+    sem_destroy( &stream->semaphore );
+
+    PaUtil_FreeMemory( stream );
+}
+
+/** Translate from PA format to OSS native.
+ *
+ */
+static PaError Pa2OssFormat( PaSampleFormat paFormat, int *ossFormat )
+{
+    switch( paFormat )
+    {
+        case paUInt8:
+            *ossFormat = AFMT_U8;
+            break;
+        case paInt8:
+            *ossFormat = AFMT_S8;
+            break;
+        case paInt16:
+            *ossFormat = AFMT_S16_NE;
+            break;
+#ifdef AFMT_S32_NE
+        case paInt32:
+            *ossFormat = AFMT_S32_NE;
+            break;
+#endif
+        default:
+            return paInternalError;     /* This shouldn't happen */
+    }
+
+    return paNoError;
+}
+
+/** Return the PA-compatible formats that this device can support.
+ *
+ */
+static PaError GetAvailableFormats( PaOssStreamComponent *component, PaSampleFormat *availableFormats )
+{
+    PaError result = paNoError;
+    int mask = 0;
+    PaSampleFormat frmts = 0;
+
+    ENSURE_( ioctl( component->fd, SNDCTL_DSP_GETFMTS, &mask ), paUnanticipatedHostError );
+    if( mask & AFMT_U8 )
+        frmts |= paUInt8;
+    if( mask & AFMT_S8 )
+        frmts |= paInt8;
+    if( mask & AFMT_S16_NE )
+        frmts |= paInt16;
+#ifdef AFMT_S32_NE
+    if( mask & AFMT_S32_NE )
+        frmts |= paInt32;
+#endif
+    if( frmts == 0 )
+        result = paSampleFormatNotSupported;
+
+    *availableFormats = frmts;
+
+error:
+    return result;
+}
+
+static unsigned int PaOssStreamComponent_FrameSize( PaOssStreamComponent *component )
+{
+    return Pa_GetSampleSize( component->hostFormat ) * component->hostChannelCount;
+}
+
+/** Buffer size in bytes.
+ *
+ */
+static unsigned long PaOssStreamComponent_BufferSize( PaOssStreamComponent *component )
+{
+    return PaOssStreamComponent_FrameSize( component ) * component->hostFrames * component->numBufs;
+}
+
+/** Configure stream component device parameters.
+ */
+static PaError PaOssStreamComponent_Configure( PaOssStreamComponent *component, double sampleRate, unsigned long
+        framesPerBuffer, StreamMode streamMode, PaOssStreamComponent *master )
+{
+    PaError result = paNoError;
+    int temp, nativeFormat;
+    int sr = (int)sampleRate;
+    PaSampleFormat availableFormats = 0, hostFormat = 0;
+    int chans = component->userChannelCount;
+    int frgmt;
+    int numBufs;
+    int bytesPerBuf;
+    unsigned long bufSz;
+    unsigned long fragSz;
+    audio_buf_info bufInfo;
+
+    /* We may have a situation where only one component (the master) is configured, if both point to the same device.
+     * In that case, the second component will copy settings from the other */
+    if( !master )
+    {
+        /* Aspect BufferSettings: If framesPerBuffer is unspecified we have to infer a suitable fragment size.
+         * The hardware need not respect the requested fragment size, so we may have to adapt.
+         */
+        if( framesPerBuffer == paFramesPerBufferUnspecified )
+        {
+            /* Aim for 4 fragments in the complete buffer; the latency comes from 3 of these */
+            fragSz = (unsigned long)(component->latency * sampleRate / 3);
+            bufSz = fragSz * 4;
+        }
+        else
+        {
+            fragSz = framesPerBuffer;
+            bufSz = (unsigned long)(component->latency * sampleRate) + fragSz; /* Latency + 1 buffer */
+        }
+
+        PA_ENSURE( GetAvailableFormats( component, &availableFormats ) );
+        hostFormat = PaUtil_SelectClosestAvailableFormat( availableFormats, component->userFormat );
+
+        /* OSS demands at least 2 buffers, and 16 bytes per buffer */
+        numBufs = (int)PA_MAX( bufSz / fragSz, 2 );
+        bytesPerBuf = PA_MAX( fragSz * Pa_GetSampleSize( hostFormat ) * chans, 16 );
+
+        /* The fragment parameters are encoded like this:
+         * Most significant byte: number of fragments
+         * Least significant byte: exponent of fragment size (i.e., for 256, 8)
+         */
+        frgmt = (numBufs << 16) + (CalcHigherLogTwo( bytesPerBuf ) & 0xffff);
+        ENSURE_( ioctl( component->fd, SNDCTL_DSP_SETFRAGMENT, &frgmt ), paUnanticipatedHostError );
+
+        /* A: according to the OSS programmer's guide parameters should be set in this order:
+         * format, channels, rate */
+
+        /* This format should be deemed good before we get this far */
+        PA_ENSURE( Pa2OssFormat( hostFormat, &temp ) );
+        nativeFormat = temp;
+        ENSURE_( ioctl( component->fd, SNDCTL_DSP_SETFMT, &temp ), paUnanticipatedHostError );
+        PA_UNLESS( temp == nativeFormat, paInternalError );
+
+        /* try to set the number of channels */
+        ENSURE_( ioctl( component->fd, SNDCTL_DSP_CHANNELS, &chans ), paSampleFormatNotSupported );   /* XXX: Should be paInvalidChannelCount? */
+        /* It's possible that the minimum number of host channels is greater than what the user requested */
+        PA_UNLESS( chans >= component->userChannelCount, paInvalidChannelCount );
+
+        /* try to set the sample rate */
+        ENSURE_( ioctl( component->fd, SNDCTL_DSP_SPEED, &sr ), paInvalidSampleRate );
+
+        /* reject if there's no sample rate within 1% of the one requested */
+        if( (fabs( sampleRate - sr ) / sampleRate) > 0.01 )
+        {
+            PA_DEBUG(("%s: Wanted %f, closest sample rate was %d\n", __FUNCTION__, sampleRate, sr ));
+            PA_ENSURE( paInvalidSampleRate );
+        }
+
+        ENSURE_( ioctl( component->fd, streamMode == StreamMode_In ? SNDCTL_DSP_GETISPACE : SNDCTL_DSP_GETOSPACE, &bufInfo ),
+                paUnanticipatedHostError );
+        component->numBufs = bufInfo.fragstotal;
+
+        /* This needs to be the last ioctl call before the first read/write, according to the OSS programmer's guide */
+        ENSURE_( ioctl( component->fd, SNDCTL_DSP_GETBLKSIZE, &bytesPerBuf ), paUnanticipatedHostError );
+
+        component->hostFrames = bytesPerBuf / Pa_GetSampleSize( hostFormat ) / chans;
+        component->hostChannelCount = chans;
+        component->hostFormat = hostFormat;
+    }
+    else
+    {
+        component->hostFormat = master->hostFormat;
+        component->hostFrames = master->hostFrames;
+        component->hostChannelCount = master->hostChannelCount;
+        component->numBufs = master->numBufs;
+    }
+
+    PA_UNLESS( component->buffer = PaUtil_AllocateMemory( PaOssStreamComponent_BufferSize( component ) ),
+            paInsufficientMemory );
+
+error:
+    return result;
+}
+
+static PaError PaOssStreamComponent_Read( PaOssStreamComponent *component, unsigned long *frames )
+{
+    PaError result = paNoError;
+    size_t len = *frames * PaOssStreamComponent_FrameSize( component );
+    ssize_t bytesRead;
+
+    ENSURE_( bytesRead = read( component->fd, component->buffer, len ), paUnanticipatedHostError );
+    *frames = bytesRead / PaOssStreamComponent_FrameSize( component );
+    /* TODO: Handle condition where number of frames read doesn't equal number of frames requested */
+
+error:
+    return result;
+}
+
+static PaError PaOssStreamComponent_Write( PaOssStreamComponent *component, unsigned long *frames )
+{
+    PaError result = paNoError;
+    size_t len = *frames * PaOssStreamComponent_FrameSize( component );
+    ssize_t bytesWritten;
+
+    ENSURE_( bytesWritten = write( component->fd, component->buffer, len ), paUnanticipatedHostError );
+    *frames = bytesWritten / PaOssStreamComponent_FrameSize( component );
+    /* TODO: Handle condition where number of frames written doesn't equal number of frames requested */
+
+error:
+    return result;
+}
+
+/** Configure the stream according to input/output parameters.
+ *
+ * Aspect StreamChannels: The minimum number of channels supported by the device may exceed that requested by
+ * the user, if so we'll record the actual number of host channels and adapt later.
+ */
+static PaError PaOssStream_Configure( PaOssStream *stream, double sampleRate, unsigned long framesPerBuffer,
+        double *inputLatency, double *outputLatency )
+{
+    PaError result = paNoError;
+    int duplex = stream->capture && stream->playback;
+    unsigned long framesPerHostBuffer = 0;
+
+    /* We should request full duplex first thing after opening the device */
+    if( duplex && stream->sharedDevice )
+        ENSURE_( ioctl( stream->capture->fd, SNDCTL_DSP_SETDUPLEX, 0 ), paUnanticipatedHostError );
+
+    if( stream->capture )
+    {
+        PaOssStreamComponent *component = stream->capture;
+        PA_ENSURE( PaOssStreamComponent_Configure( component, sampleRate, framesPerBuffer, StreamMode_In,
+                    NULL ) );
+
+        assert( component->hostChannelCount > 0 );
+        assert( component->hostFrames > 0 );
+
+        *inputLatency = (component->hostFrames * (component->numBufs - 1)) / sampleRate;
+    }
+    if( stream->playback )
+    {
+        PaOssStreamComponent *component = stream->playback, *master = stream->sharedDevice ? stream->capture : NULL;
+        PA_ENSURE( PaOssStreamComponent_Configure( component, sampleRate, framesPerBuffer, StreamMode_Out,
+                    master ) );
+
+        assert( component->hostChannelCount > 0 );
+        assert( component->hostFrames > 0 );
+
+        *outputLatency = (component->hostFrames * (component->numBufs - 1)) / sampleRate;
+    }
+
+    if( duplex )
+        framesPerHostBuffer = PA_MIN( stream->capture->hostFrames, stream->playback->hostFrames );
+    else if( stream->capture )
+        framesPerHostBuffer = stream->capture->hostFrames;
+    else if( stream->playback )
+        framesPerHostBuffer = stream->playback->hostFrames;
+
+    stream->framesPerHostBuffer = framesPerHostBuffer;
+    stream->pollTimeout = (int) ceil( 1e6 * framesPerHostBuffer / sampleRate );    /* Period in usecs, rounded up */
+
+    stream->sampleRate = stream->streamRepresentation.streamInfo.sampleRate = sampleRate;
+
+error:
+    return result;
+}
+
+/* see pa_hostapi.h for a list of validity guarantees made about OpenStream parameters */
+
+/** Open a PA OSS stream.
+ *
+ * Aspect StreamChannels: The number of channels is specified per direction (in/out), and can differ between the
+ * two. However, OSS doesn't support separate configuration spaces for capture and playback so if both
+ * directions are the same device we will demand the same number of channels. The number of channels can range
+ * from 1 to the maximum supported by the device.
+ *
+ * Aspect BufferSettings: If framesPerBuffer != paFramesPerBufferUnspecified the number of frames per callback
+ * must reflect this, in addition the host latency per device should approximate the corresponding
+ * suggestedLatency. Based on these constraints we need to determine a number of frames per host buffer that
+ * both capture and playback can agree on (they can be different devices), the buffer processor can adapt
+ * between host and user buffer size, but the ratio should preferably be integral.
+ */
+static PaError OpenStream( struct PaUtilHostApiRepresentation *hostApi,
+                           PaStream** s,
+                           const PaStreamParameters *inputParameters,
+                           const PaStreamParameters *outputParameters,
+                           double sampleRate,
+                           unsigned long framesPerBuffer,
+                           PaStreamFlags streamFlags,
+                           PaStreamCallback *streamCallback,
+                           void *userData )
+{
+    PaError result = paNoError;
+    PaOSSHostApiRepresentation *ossHostApi = (PaOSSHostApiRepresentation*)hostApi;
+    PaOssStream *stream = NULL;
+    int inputChannelCount = 0, outputChannelCount = 0;
+    PaSampleFormat inputSampleFormat = 0, outputSampleFormat = 0, inputHostFormat = 0, outputHostFormat = 0;
+    const PaDeviceInfo *inputDeviceInfo = 0, *outputDeviceInfo = 0;
+    int bpInitialized = 0;
+    double inLatency = 0., outLatency = 0.;
+    int i = 0;
+
+    /* validate platform specific flags */
+    if( (streamFlags & paPlatformSpecificFlags) != 0 )
+        return paInvalidFlag; /* unexpected platform specific flag */
+
+    if( inputParameters )
+    {
+        /* unless alternate device specification is supported, reject the use of
+            paUseHostApiSpecificDeviceSpecification */
+        inputDeviceInfo = hostApi->deviceInfos[inputParameters->device];
+        PA_ENSURE( ValidateParameters( inputParameters, inputDeviceInfo, StreamMode_In ) );
+
+        inputChannelCount = inputParameters->channelCount;
+        inputSampleFormat = inputParameters->sampleFormat;
+    }
+    if( outputParameters )
+    {
+        outputDeviceInfo = hostApi->deviceInfos[outputParameters->device];
+        PA_ENSURE( ValidateParameters( outputParameters, outputDeviceInfo, StreamMode_Out ) );
+
+        outputChannelCount = outputParameters->channelCount;
+        outputSampleFormat = outputParameters->sampleFormat;
+    }
+
+    /* Aspect StreamChannels: We currently demand that number of input and output channels are the same, if the same
+     * device is opened for both directions
+     */
+    if( inputChannelCount > 0 && outputChannelCount > 0 )
+    {
+        if( inputParameters->device == outputParameters->device )
+        {
+            if( inputParameters->channelCount != outputParameters->channelCount )
+                return paInvalidChannelCount;
+        }
+    }
+
+    /* Round framesPerBuffer to the next power-of-two to make OSS happy. */
+    if( framesPerBuffer != paFramesPerBufferUnspecified )
+    {
+        framesPerBuffer &= INT_MAX;
+        for (i = 1; framesPerBuffer > i; i <<= 1) ;
+        framesPerBuffer = i;
+    }
+
+    /* allocate and do basic initialization of the stream structure */
+    PA_UNLESS( stream = (PaOssStream*)PaUtil_AllocateMemory( sizeof(PaOssStream) ), paInsufficientMemory );
+    PA_ENSURE( PaOssStream_Initialize( stream, inputParameters, outputParameters, streamCallback, userData, streamFlags, ossHostApi ) );
+
+    PA_ENSURE( PaOssStream_Configure( stream, sampleRate, framesPerBuffer, &inLatency, &outLatency ) );
+
+    PaUtil_InitializeCpuLoadMeasurer( &stream->cpuLoadMeasurer, sampleRate );
+
+    if( inputParameters )
+    {
+        inputHostFormat = stream->capture->hostFormat;
+        stream->streamRepresentation.streamInfo.inputLatency = inLatency +
+            PaUtil_GetBufferProcessorInputLatencyFrames( &stream->bufferProcessor ) / sampleRate;
+    }
+    if( outputParameters )
+    {
+        outputHostFormat = stream->playback->hostFormat;
+        stream->streamRepresentation.streamInfo.outputLatency = outLatency +
+            PaUtil_GetBufferProcessorOutputLatencyFrames( &stream->bufferProcessor ) / sampleRate;
+    }
+
+    /* Initialize buffer processor with fixed host buffer size.
+     * Aspect StreamSampleFormat: Here we commit the user and host sample formats, PA infrastructure will
+     * convert between the two.
+     */
+    PA_ENSURE( PaUtil_InitializeBufferProcessor( &stream->bufferProcessor,
+              inputChannelCount, inputSampleFormat, inputHostFormat, outputChannelCount, outputSampleFormat,
+              outputHostFormat, sampleRate, streamFlags, framesPerBuffer, stream->framesPerHostBuffer,
+              paUtilFixedHostBufferSize, streamCallback, userData ) );
+    bpInitialized = 1;
+
+    *s = (PaStream*)stream;
+
+    return result;
+
+error:
+    if( bpInitialized )
+        PaUtil_TerminateBufferProcessor( &stream->bufferProcessor );
+    if( stream )
+        PaOssStream_Terminate( stream );
+
+    return result;
+}
+
+/*! Poll on I/O filedescriptors.
+
+  Poll till we've determined there's data for read or write. In the full-duplex case,
+  we don't want to hang around forever waiting for either input or output frames, so
+  whenever we have a timed out filedescriptor we check if we're nearing under/overrun
+  for the other direction (critical limit set at one buffer). If so, we exit the waiting
+  state, and go on with what we got. We align the number of frames on a host buffer
+  boundary because it is possible that the buffer size differs for the two directions and
+  the host buffer size is a compromise between the two.
+  */
+static PaError PaOssStream_WaitForFrames( PaOssStream *stream, unsigned long *frames )
+{
+    PaError result = paNoError;
+    int pollPlayback = 0, pollCapture = 0;
+    int captureAvail = INT_MAX, playbackAvail = INT_MAX, commonAvail;
+    audio_buf_info bufInfo;
+    /* int ofs = 0, nfds = stream->nfds; */
+    fd_set readFds, writeFds;
+    int nfds = 0;
+    struct timeval selectTimeval = {0, 0};
+    unsigned long timeout = stream->pollTimeout;    /* In usecs */
+    int captureFd = -1, playbackFd = -1;
+
+    assert( stream );
+    assert( frames );
+
+    if( stream->capture )
+    {
+        pollCapture = 1;
+        captureFd = stream->capture->fd;
+        /* stream->capture->pfd->events = POLLIN; */
+    }
+    if( stream->playback )
+    {
+        pollPlayback = 1;
+        playbackFd = stream->playback->fd;
+        /* stream->playback->pfd->events = POLLOUT; */
+    }
+
+    FD_ZERO( &readFds );
+    FD_ZERO( &writeFds );
+
+    while( pollPlayback || pollCapture )
+    {
+#ifdef PTHREAD_CANCELED
+        pthread_testcancel();
+#else
+        /* avoid indefinite waiting on thread not supporting cancellation */
+        if( stream->callbackStop || stream->callbackAbort )
+        {
+            PA_DEBUG(( "Cancelling PaOssStream_WaitForFrames\n" ));
+            (*frames) = 0;
+            return paNoError;
+        }
+#endif
+
+        /* select may modify the timeout parameter */
+        selectTimeval.tv_usec = timeout;
+        nfds = 0;
+
+        if( pollCapture )
+        {
+            FD_SET( captureFd, &readFds );
+            nfds = captureFd + 1;
+        }
+        if( pollPlayback )
+        {
+            FD_SET( playbackFd, &writeFds );
+            nfds = PA_MAX( nfds, playbackFd + 1 );
+        }
+        ENSURE_( select( nfds, &readFds, &writeFds, NULL, &selectTimeval ), paUnanticipatedHostError );
+        /*
+        if( poll( stream->pfds + ofs, nfds, stream->pollTimeout ) < 0 )
+        {
+
+            ENSURE_( -1, paUnanticipatedHostError );
+        }
+        */
+#ifdef PTHREAD_CANCELED
+        pthread_testcancel();
+#else
+        /* avoid indefinite waiting on thread not supporting cancellation */
+        if( stream->callbackStop || stream->callbackAbort )
+        {
+            PA_DEBUG(( "Cancelling PaOssStream_WaitForFrames\n" ));
+            (*frames) = 0;
+            return paNoError;
+        }
+#endif
+        if( pollCapture )
+        {
+            if( FD_ISSET( captureFd, &readFds ) )
+            {
+                FD_CLR( captureFd, &readFds );
+                pollCapture = 0;
+            }
+            /*
+            if( stream->capture->pfd->revents & POLLIN )
+            {
+                --nfds;
+                ++ofs;
+                pollCapture = 0;
+            }
+            */
+            else if( stream->playback ) /* Timed out, go on with playback? */
+            {
+                /*PA_DEBUG(( "%s: Trying to poll again for capture frames, pollTimeout: %d\n",
+                            __FUNCTION__, stream->pollTimeout ));*/
+            }
+        }
+        if( pollPlayback )
+        {
+            if( FD_ISSET( playbackFd, &writeFds ) )
+            {
+                FD_CLR( playbackFd, &writeFds );
+                pollPlayback = 0;
+            }
+            /*
+            if( stream->playback->pfd->revents & POLLOUT )
+            {
+                --nfds;
+                pollPlayback = 0;
+            }
+            */
+            else if( stream->capture )  /* Timed out, go on with capture? */
+            {
+                /*PA_DEBUG(( "%s: Trying to poll again for playback frames, pollTimeout: %d\n\n",
+                            __FUNCTION__, stream->pollTimeout ));*/
+            }
+        }
+    }
+
+    if( stream->capture )
+    {
+        ENSURE_( ioctl( captureFd, SNDCTL_DSP_GETISPACE, &bufInfo ), paUnanticipatedHostError );
+        captureAvail = bufInfo.fragments * stream->capture->hostFrames;
+        if( !captureAvail )
+            PA_DEBUG(( "%s: captureAvail: 0\n", __FUNCTION__ ));
+
+        captureAvail = captureAvail == 0 ? INT_MAX : captureAvail;      /* Disregard if zero */
+    }
+    if( stream->playback )
+    {
+        ENSURE_( ioctl( playbackFd, SNDCTL_DSP_GETOSPACE, &bufInfo ), paUnanticipatedHostError );
+        playbackAvail = bufInfo.fragments * stream->playback->hostFrames;
+        if( !playbackAvail )
+        {
+            PA_DEBUG(( "%s: playbackAvail: 0\n", __FUNCTION__ ));
+        }
+
+        playbackAvail = playbackAvail == 0 ? INT_MAX : playbackAvail;      /* Disregard if zero */
+    }
+
+    commonAvail = PA_MIN( captureAvail, playbackAvail );
+    if( commonAvail == INT_MAX )
+        commonAvail = 0;
+    commonAvail -= commonAvail % stream->framesPerHostBuffer;
+
+    assert( commonAvail != INT_MAX );
+    assert( commonAvail >= 0 );
+    *frames = commonAvail;
+
+error:
+    return result;
+}
+
+/** Prepare stream for capture/playback.
+ *
+ * In order to synchronize capture and playback properly we use the SETTRIGGER command.
+ */
+static PaError PaOssStream_Prepare( PaOssStream *stream )
+{
+    PaError result = paNoError;
+    int enableBits = 0;
+
+    if( stream->triggered )
+        return result;
+
+    /* The OSS reference instructs us to clear direction bits before setting them.*/
+    if( stream->playback )
+        ENSURE_( ioctl( stream->playback->fd, SNDCTL_DSP_SETTRIGGER, &enableBits ), paUnanticipatedHostError );
+    if( stream->capture )
+        ENSURE_( ioctl( stream->capture->fd, SNDCTL_DSP_SETTRIGGER, &enableBits ), paUnanticipatedHostError );
+
+    if( stream->playback )
+    {
+        size_t bufSz = PaOssStreamComponent_BufferSize( stream->playback );
+        memset( stream->playback->buffer, 0, bufSz );
+
+        /* Looks like we have to turn off blocking before we try this, but if we don't fill the buffer
+         * OSS will complain. */
+        PA_ENSURE( ModifyBlocking( stream->playback->fd, 0 ) );
+        while (1)
+        {
+            if( write( stream->playback->fd, stream->playback->buffer, bufSz ) < 0 )
+                break;
+        }
+        PA_ENSURE( ModifyBlocking( stream->playback->fd, 1 ) );
+    }
+
+    if( stream->sharedDevice )
+    {
+        enableBits = PCM_ENABLE_INPUT | PCM_ENABLE_OUTPUT;
+        ENSURE_( ioctl( stream->capture->fd, SNDCTL_DSP_SETTRIGGER, &enableBits ), paUnanticipatedHostError );
+    }
+    else
+    {
+        if( stream->capture )
+        {
+            enableBits = PCM_ENABLE_INPUT;
+            ENSURE_( ioctl( stream->capture->fd, SNDCTL_DSP_SETTRIGGER, &enableBits ), paUnanticipatedHostError );
+        }
+        if( stream->playback )
+        {
+            enableBits = PCM_ENABLE_OUTPUT;
+            ENSURE_( ioctl( stream->playback->fd, SNDCTL_DSP_SETTRIGGER, &enableBits ), paUnanticipatedHostError );
+        }
+    }
+
+    /* Ok, we have triggered the stream */
+    stream->triggered = 1;
+
+error:
+    return result;
+}
+
+/** Stop audio processing
+ *
+ */
+static PaError PaOssStream_Stop( PaOssStream *stream, int abort )
+{
+    PaError result = paNoError;
+
+    /* Looks like the only safe way to stop audio without reopening the device is SNDCTL_DSP_POST.
+     * Also disable capture/playback till the stream is started again.
+     */
+    int captureErr = 0, playbackErr = 0;
+    if( stream->capture )
+    {
+        if( (captureErr = ioctl( stream->capture->fd, SNDCTL_DSP_POST, 0 )) < 0 )
+        {
+            PA_DEBUG(( "%s: Failed to stop capture device, error: %d\n", __FUNCTION__, captureErr ));
+        }
+    }
+    if( stream->playback && !stream->sharedDevice )
+    {
+        if( (playbackErr = ioctl( stream->playback->fd, SNDCTL_DSP_POST, 0 )) < 0 )
+        {
+            PA_DEBUG(( "%s: Failed to stop playback device, error: %d\n", __FUNCTION__, playbackErr ));
+        }
+    }
+
+    if( captureErr || playbackErr )
+    {
+        result = paUnanticipatedHostError;
+    }
+
+    return result;
+}
+
+/** Clean up after thread exit.
+ *
+ * Aspect StreamState: If the user has registered a streamFinishedCallback it will be called here
+ */
+static void OnExit( void *data )
+{
+    PaOssStream *stream = (PaOssStream *) data;
+    assert( data );
+
+    PaUtil_ResetCpuLoadMeasurer( &stream->cpuLoadMeasurer );
+
+    PaOssStream_Stop( stream, stream->callbackAbort );
+
+    PA_DEBUG(( "OnExit: Stoppage\n" ));
+
+    /* Eventually notify user all buffers have played */
+    if( stream->streamRepresentation.streamFinishedCallback )
+        stream->streamRepresentation.streamFinishedCallback( stream->streamRepresentation.userData );
+
+    stream->callbackAbort = 0;      /* Clear state */
+    stream->isActive = 0;
+}
+
+static PaError SetUpBuffers( PaOssStream *stream, unsigned long framesAvail )
+{
+    PaError result = paNoError;
+
+    if( stream->capture )
+    {
+        PaUtil_SetInterleavedInputChannels( &stream->bufferProcessor, 0, stream->capture->buffer,
+                stream->capture->hostChannelCount );
+        PaUtil_SetInputFrameCount( &stream->bufferProcessor, framesAvail );
+    }
+    if( stream->playback )
+    {
+        PaUtil_SetInterleavedOutputChannels( &stream->bufferProcessor, 0, stream->playback->buffer,
+                stream->playback->hostChannelCount );
+        PaUtil_SetOutputFrameCount( &stream->bufferProcessor, framesAvail );
+    }
+
+    return result;
+}
+
+/** Thread procedure for callback processing.
+ *
+ * Aspect StreamState: StartStream will wait on this to initiate audio processing, useful in case the
+ * callback should be used for buffer priming. When the stream is cancelled a separate function will
+ * take care of the transition to the Callback Finished state (the stream isn't considered Stopped
+ * before StopStream() or AbortStream() are called).
+ */
+static void *PaOSS_AudioThreadProc( void *userData )
+{
+    PaError result = paNoError;
+    PaOssStream *stream = (PaOssStream*)userData;
+    unsigned long framesAvail = 0, framesProcessed = 0;
+    int callbackResult = paContinue;
+    int triggered = stream->triggered;  /* See if SNDCTL_DSP_TRIGGER has been issued already */
+    int initiateProcessing = triggered;    /* Already triggered? */
+    PaStreamCallbackFlags cbFlags = 0;  /* We might want to keep state across iterations */
+    PaStreamCallbackTimeInfo timeInfo = {0,0,0}; /* TODO: IMPLEMENT ME */
+
+    /*
+#if ( SOUND_VERSION > 0x030904 )
+        audio_errinfo errinfo;
+#endif
+*/
+
+    assert( stream );
+
+    pthread_cleanup_push( &OnExit, stream );    /* Execute OnExit when exiting */
+
+    /* The first time the stream is started we use SNDCTL_DSP_TRIGGER to accurately start capture and
+     * playback in sync, when the stream is restarted after being stopped we simply start by reading/
+     * writing.
+     */
+    PA_ENSURE( PaOssStream_Prepare( stream ) );
+
+    /* If we are to initiate processing implicitly by reading/writing data, we start off in blocking mode */
+    if( initiateProcessing )
+    {
+        /* Make sure devices are in blocking mode */
+        if( stream->capture )
+            ModifyBlocking( stream->capture->fd, 1 );
+        if( stream->playback )
+            ModifyBlocking( stream->playback->fd, 1 );
+    }
+
+    while( 1 )
+    {
+#ifdef PTHREAD_CANCELED
+        pthread_testcancel();
+#else
+        if( stream->callbackAbort ) /* avoid indefinite waiting on thread not supporting cancellation */
+        {
+            PA_DEBUG(( "Aborting callback thread\n" ));
+            break;
+        }
+#endif
+        if( stream->callbackStop && callbackResult == paContinue )
+        {
+            PA_DEBUG(( "Setting callbackResult to paComplete\n" ));
+            callbackResult = paComplete;
+        }
+
+        /* Aspect StreamState: Because of the messy OSS scheme we can't explicitly trigger device start unless
+         * the stream has been recently started, we will have to go right ahead and read/write in blocking
+         * fashion to trigger operation. Therefore we begin with processing one host buffer before we switch
+         * to non-blocking mode.
+         */
+        if( !initiateProcessing )
+        {
+            /* Wait on available frames */
+            PA_ENSURE( PaOssStream_WaitForFrames( stream, &framesAvail ) );
+            assert( framesAvail % stream->framesPerHostBuffer == 0 );
+        }
+        else
+        {
+            framesAvail = stream->framesPerHostBuffer;
+        }
+
+        while( framesAvail > 0 )
+        {
+            unsigned long frames = framesAvail;
+
+#ifdef PTHREAD_CANCELED
+            pthread_testcancel();
+#else
+            if( stream->callbackStop )
+            {
+                PA_DEBUG(( "Setting callbackResult to paComplete\n" ));
+                callbackResult = paComplete;
+            }
+
+            if( stream->callbackAbort ) /* avoid indefinite waiting on thread not supporting cancellation */
+            {
+                PA_DEBUG(( "Aborting callback thread\n" ));
+                break;
+            }
+#endif
+            PaUtil_BeginCpuLoadMeasurement( &stream->cpuLoadMeasurer );
+
+            /* Read data */
+            if ( stream->capture )
+            {
+                PA_ENSURE( PaOssStreamComponent_Read( stream->capture, &frames ) );
+                if( frames < framesAvail )
+                {
+                    PA_DEBUG(( "Read %lu less frames than requested\n", framesAvail - frames ));
+                    framesAvail = frames;
+                }
+            }
+
+#if ( SOUND_VERSION >= 0x030904 )
+            /*
+               Check with OSS to see if there have been any under/overruns
+               since last time we checked.
+               */
+            /*
+            if( ioctl( stream->deviceHandle, SNDCTL_DSP_GETERROR, &errinfo ) >= 0 )
+            {
+                if( errinfo.play_underruns )
+                    cbFlags |= paOutputUnderflow ;
+                if( errinfo.record_underruns )
+                    cbFlags |= paInputUnderflow ;
+            }
+            else
+                PA_DEBUG(( "SNDCTL_DSP_GETERROR command failed: %s\n", strerror( errno ) ));
+                */
+#endif
+
+            PaUtil_BeginBufferProcessing( &stream->bufferProcessor, &timeInfo,
+                    cbFlags );
+            cbFlags = 0;
+            PA_ENSURE( SetUpBuffers( stream, framesAvail ) );
+
+            framesProcessed = PaUtil_EndBufferProcessing( &stream->bufferProcessor,
+                    &callbackResult );
+            assert( framesProcessed == framesAvail );
+            PaUtil_EndCpuLoadMeasurement( &stream->cpuLoadMeasurer, framesProcessed );
+
+            if ( stream->playback )
+            {
+                frames = framesAvail;
+
+                PA_ENSURE( PaOssStreamComponent_Write( stream->playback, &frames ) );
+                if( frames < framesAvail )
+                {
+                    /* TODO: handle bytesWritten != bytesRequested (slippage?) */
+                    PA_DEBUG(( "Wrote %lu less frames than requested\n", framesAvail - frames ));
+                }
+            }
+
+            framesAvail -= framesProcessed;
+            stream->framesProcessed += framesProcessed;
+
+            if( callbackResult != paContinue )
+                break;
+        }
+
+        if( initiateProcessing || !triggered )
+        {
+            /* Non-blocking */
+            if( stream->capture )
+                PA_ENSURE( ModifyBlocking( stream->capture->fd, 0 ) );
+            if( stream->playback && !stream->sharedDevice )
+                PA_ENSURE( ModifyBlocking( stream->playback->fd, 0 ) );
+
+            initiateProcessing = 0;
+            sem_post( &stream->semaphore );
+        }
+
+        if( callbackResult != paContinue )
+        {
+            stream->callbackAbort = callbackResult == paAbort;
+            if( stream->callbackAbort || PaUtil_IsBufferProcessorOutputEmpty( &stream->bufferProcessor ) )
+                break;
+        }
+    }
+
+    pthread_cleanup_pop( 1 );
+
+error:
+    pthread_exit( NULL );
+}
+
+/** Close the stream.
+ *
+ */
+static PaError CloseStream( PaStream* s )
+{
+    PaError result = paNoError;
+    PaOssStream *stream = (PaOssStream*)s;
+
+    assert( stream );
+
+    PaUtil_TerminateBufferProcessor( &stream->bufferProcessor );
+    PaOssStream_Terminate( stream );
+
+    return result;
+}
+
+/** Start the stream.
+ *
+ * Aspect StreamState: After returning, the stream shall be in the Active state, implying that an eventual
+ * callback will be repeatedly called in a separate thread. If a separate thread is started this function
+ * will block until it has started processing audio, otherwise audio processing is started directly.
+ */
+static PaError StartStream( PaStream *s )
+{
+    PaError result = paNoError;
+    PaOssStream *stream = (PaOssStream*)s;
+
+    stream->isActive = 1;
+    stream->isStopped = 0;
+    stream->lastPosPtr = 0;
+    stream->lastStreamBytes = 0;
+    stream->framesProcessed = 0;
+
+    /* only use the thread for callback streams */
+    if( stream->bufferProcessor.streamCallback )
+    {
+        PA_ENSURE( PaUtil_StartThreading( &stream->threading, &PaOSS_AudioThreadProc, stream ) );
+        sem_wait( &stream->semaphore );
+    }
+    else
+        PA_ENSURE( PaOssStream_Prepare( stream ) );
+
+error:
+    return result;
+}
+
+static PaError RealStop( PaOssStream *stream, int abort )
+{
+    PaError result = paNoError;
+
+    if( stream->callbackMode )
+    {
+        if( abort )
+            stream->callbackAbort = 1;
+        else
+            stream->callbackStop = 1;
+
+        PA_ENSURE( PaUtil_CancelThreading( &stream->threading, !abort, NULL ) );
+
+        stream->callbackStop = stream->callbackAbort = 0;
+    }
+    else
+        PA_ENSURE( PaOssStream_Stop( stream, abort ) );
+
+    stream->isStopped = 1;
+
+error:
+    return result;
+}
+
+/** Stop the stream.
+ *
+ * Aspect StreamState: This will cause the stream to transition to the Stopped state, playing all enqueued
+ * buffers.
+ */
+static PaError StopStream( PaStream *s )
+{
+    return RealStop( (PaOssStream *)s, 0 );
+}
+
+/** Abort the stream.
+ *
+ * Aspect StreamState: This will cause the stream to transition to the Stopped state, discarding all enqueued
+ * buffers. Note that the buffers are not currently correctly discarded, this is difficult without closing
+ * the OSS device.
+ */
+static PaError AbortStream( PaStream *s )
+{
+    return RealStop( (PaOssStream *)s, 1 );
+}
+
+/** Is the stream in the Stopped state.
+ *
+ */
+static PaError IsStreamStopped( PaStream *s )
+{
+    PaOssStream *stream = (PaOssStream*)s;
+
+    return (stream->isStopped);
+}
+
+/** Is the stream in the Active state.
+ *
+ */
+static PaError IsStreamActive( PaStream *s )
+{
+    PaOssStream *stream = (PaOssStream*)s;
+
+    return (stream->isActive);
+}
+
+static PaTime GetStreamTime( PaStream *s )
+{
+    PaOssStream *stream = (PaOssStream*)s;
+    count_info info;
+    int delta;
+
+    if( stream->playback ) {
+        if( ioctl( stream->playback->fd, SNDCTL_DSP_GETOPTR, &info) == 0 ) {
+            delta = ( info.bytes - stream->lastPosPtr ) /* & 0x000FFFFF*/;
+            return (float)(stream->lastStreamBytes + delta) / PaOssStreamComponent_FrameSize( stream->playback ) / stream->sampleRate;
+        }
+    }
+    else {
+        if (ioctl( stream->capture->fd, SNDCTL_DSP_GETIPTR, &info) == 0) {
+            delta = (info.bytes - stream->lastPosPtr) /*& 0x000FFFFF*/;
+            return (float)(stream->lastStreamBytes + delta) / PaOssStreamComponent_FrameSize( stream->capture ) / stream->sampleRate;
+        }
+    }
+
+    /* the ioctl failed, but we can still give a coarse estimate */
+
+    return stream->framesProcessed / stream->sampleRate;
+}
+
+
+static double GetStreamCpuLoad( PaStream* s )
+{
+    PaOssStream *stream = (PaOssStream*)s;
+
+    return PaUtil_GetCpuLoad( &stream->cpuLoadMeasurer );
+}
+
+
+/*
+    As separate stream interfaces are used for blocking and callback
+    streams, the following functions can be guaranteed to only be called
+    for blocking streams.
+*/
+
+
+static PaError ReadStream( PaStream* s,
+                           void *buffer,
+                           unsigned long frames )
+{
+    PaError result = paNoError;
+    PaOssStream *stream = (PaOssStream*)s;
+    int bytesRequested, bytesRead;
+    unsigned long framesRequested;
+    void *userBuffer;
+
+    /* If user input is non-interleaved, PaUtil_CopyInput will manipulate the channel pointers,
+     * so we copy the user provided pointers */
+    if( stream->bufferProcessor.userInputIsInterleaved )
+        userBuffer = buffer;
+    else /* Copy channels into local array */
+    {
+        userBuffer = stream->capture->userBuffers;
+        memcpy( (void *)userBuffer, buffer, sizeof (void *) * stream->capture->userChannelCount );
+    }
+
+    while( frames )
+    {
+        framesRequested = PA_MIN( frames, stream->capture->hostFrames );
+
+        bytesRequested = framesRequested * PaOssStreamComponent_FrameSize( stream->capture );
+        ENSURE_( (bytesRead = read( stream->capture->fd, stream->capture->buffer, bytesRequested )),
+                    paUnanticipatedHostError );
+        if ( bytesRequested != bytesRead )
+        {
+            PA_DEBUG(( "Requested %d bytes, read %d\n", bytesRequested, bytesRead ));
+            return paUnanticipatedHostError;
+        }
+
+        PaUtil_SetInputFrameCount( &stream->bufferProcessor, stream->capture->hostFrames );
+        PaUtil_SetInterleavedInputChannels( &stream->bufferProcessor, 0, stream->capture->buffer, stream->capture->hostChannelCount );
+        PaUtil_CopyInput( &stream->bufferProcessor, &userBuffer, framesRequested );
+        frames -= framesRequested;
+    }
+
+error:
+    return result;
+}
+
+
+static PaError WriteStream( PaStream *s, const void *buffer, unsigned long frames )
+{
+    PaError result = paNoError;
+    PaOssStream *stream = (PaOssStream*)s;
+    int bytesRequested, bytesWritten;
+    unsigned long framesConverted;
+    const void *userBuffer;
+
+    /* If user output is non-interleaved, PaUtil_CopyOutput will manipulate the channel pointers,
+     * so we copy the user provided pointers */
+    if( stream->bufferProcessor.userOutputIsInterleaved )
+        userBuffer = buffer;
+    else
+    {
+        /* Copy channels into local array */
+        userBuffer = stream->playback->userBuffers;
+        memcpy( (void *)userBuffer, buffer, sizeof (void *) * stream->playback->userChannelCount );
+    }
+
+    while( frames )
+    {
+        PaUtil_SetOutputFrameCount( &stream->bufferProcessor, stream->playback->hostFrames );
+        PaUtil_SetInterleavedOutputChannels( &stream->bufferProcessor, 0, stream->playback->buffer, stream->playback->hostChannelCount );
+
+        framesConverted = PaUtil_CopyOutput( &stream->bufferProcessor, &userBuffer, frames );
+        frames -= framesConverted;
+
+        bytesRequested = framesConverted * PaOssStreamComponent_FrameSize( stream->playback );
+        ENSURE_( (bytesWritten = write( stream->playback->fd, stream->playback->buffer, bytesRequested )),
+                    paUnanticipatedHostError );
+
+        if ( bytesRequested != bytesWritten )
+        {
+            PA_DEBUG(( "Requested %d bytes, wrote %d\n", bytesRequested, bytesWritten ));
+            return paUnanticipatedHostError;
+        }
+    }
+
+error:
+    return result;
+}
+
+
+static signed long GetStreamReadAvailable( PaStream* s )
+{
+    PaError result = paNoError;
+    PaOssStream *stream = (PaOssStream*)s;
+    audio_buf_info info;
+
+    ENSURE_( ioctl( stream->capture->fd, SNDCTL_DSP_GETISPACE, &info ), paUnanticipatedHostError );
+    return info.fragments * stream->capture->hostFrames;
+
+error:
+    return result;
+}
+
+
+/* TODO: Compute number of allocated bytes somewhere else, can we use ODELAY with capture */
+static signed long GetStreamWriteAvailable( PaStream* s )
+{
+    PaError result = paNoError;
+    PaOssStream *stream = (PaOssStream*)s;
+    int delay = 0;
+#ifdef SNDCTL_DSP_GETODELAY
+    ENSURE_( ioctl( stream->playback->fd, SNDCTL_DSP_GETODELAY, &delay ), paUnanticipatedHostError );
+#endif
+    return (PaOssStreamComponent_BufferSize( stream->playback ) - delay) / PaOssStreamComponent_FrameSize( stream->playback );
+
+/* Conditionally compile this to avoid warning about unused label */
+#ifdef SNDCTL_DSP_GETODELAY
+error:
+    return result;
+#endif
+}