add initial structure

1 files changed, 1601 insertions, 0 deletions

diff --git a/portaudio/qa/loopback/src/paqa.c b/portaudio/qa/loopback/src/paqa.c
new file mode 100644
index 0000000..5eb6283
--- /dev/null
+++ b/portaudio/qa/loopback/src/paqa.c
@@ -0,0 +1,1601 @@
+
+/*
+ * PortAudio Portable Real-Time Audio Library
+ * Latest Version at: http://www.portaudio.com
+ *
+ * Copyright (c) 1999-2010 Phil Burk and Ross Bencina
+ *
+ * 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.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <memory.h>
+#include <math.h>
+#include <string.h>
+
+#include "portaudio.h"
+
+#include "qa_tools.h"
+
+#include "paqa_tools.h"
+#include "audio_analyzer.h"
+#include "test_audio_analyzer.h"
+
+/** Accumulate counts for how many tests pass or fail. */
+int g_testsPassed = 0;
+int g_testsFailed = 0;
+
+#define MAX_NUM_GENERATORS                   (8)
+#define MAX_NUM_RECORDINGS                   (8)
+#define MAX_BACKGROUND_NOISE_RMS             (0.0004)
+#define LOOPBACK_DETECTION_DURATION_SECONDS  (0.8)
+#define DEFAULT_FRAMES_PER_BUFFER            (0)
+#define PAQA_WAIT_STREAM_MSEC                (100)
+#define PAQA_TEST_DURATION                   (1.2)
+
+// Use two separate streams instead of one full duplex stream.
+#define PAQA_FLAG_TWO_STREAMS       (1<<0)
+// Use bloching read/write for loopback.
+#define PAQA_FLAG_USE_BLOCKING_IO   (1<<1)
+
+const char * s_FlagOnNames[] =
+{
+    "Two Streams (Half Duplex)",
+    "Blocking Read/Write"
+};
+
+const char * s_FlagOffNames[] =
+{
+    "One Stream (Full Duplex)",
+    "Callback"
+};
+
+
+/** Parameters that describe a single test run. */
+typedef struct TestParameters_s
+{
+    PaStreamParameters inputParameters;
+    PaStreamParameters outputParameters;
+    double             sampleRate;
+    int                samplesPerFrame;
+    int                framesPerBuffer;
+    int                maxFrames;
+    double             baseFrequency;
+    double             amplitude;
+    PaStreamFlags      streamFlags;  // paClipOff, etc
+    int                flags;        // PAQA_FLAG_TWO_STREAMS, PAQA_FLAG_USE_BLOCKING_IO
+} TestParameters;
+
+typedef struct LoopbackContext_s
+{
+    // Generate a unique signal on each channel.
+    PaQaSineGenerator  generators[MAX_NUM_GENERATORS];
+    // Record each channel individually.
+    PaQaRecording      recordings[MAX_NUM_RECORDINGS];
+
+    // Reported by the stream after it's opened
+    PaTime             streamInfoInputLatency;
+    PaTime             streamInfoOutputLatency;
+
+    // Measured at runtime.
+    volatile int       callbackCount; // incremented for each callback
+    volatile int       inputBufferCount; // incremented if input buffer not NULL
+    int                inputUnderflowCount;
+    int                inputOverflowCount;
+
+    volatile int       outputBufferCount; // incremented if output buffer not NULL
+    int                outputOverflowCount;
+    int                outputUnderflowCount;
+
+    // Measure whether input or output is lagging behind.
+    volatile int       minInputOutputDelta;
+    volatile int       maxInputOutputDelta;
+
+    int                minFramesPerBuffer;
+    int                maxFramesPerBuffer;
+    int                primingCount;
+    TestParameters    *test;
+    volatile int       done;
+} LoopbackContext;
+
+typedef struct UserOptions_s
+{
+    int           sampleRate;
+    int           framesPerBuffer;
+    int           inputLatency;
+    int           outputLatency;
+    int           saveBadWaves;
+    int           verbose;
+    int           waveFileCount;
+    const char   *waveFilePath;
+    PaDeviceIndex inputDevice;
+    PaDeviceIndex outputDevice;
+} UserOptions;
+
+#define BIG_BUFFER_SIZE  (sizeof(float) * 2 * 2 * 1024)
+static unsigned char g_ReadWriteBuffer[BIG_BUFFER_SIZE];
+
+#define MAX_CONVERSION_SAMPLES   (2 * 32 * 1024)
+#define CONVERSION_BUFFER_SIZE  (sizeof(float) * 2 * MAX_CONVERSION_SAMPLES)
+static unsigned char g_ConversionBuffer[CONVERSION_BUFFER_SIZE];
+
+/*******************************************************************/
+static int RecordAndPlaySinesCallback( const void *inputBuffer, void *outputBuffer,
+                        unsigned long framesPerBuffer,
+                        const PaStreamCallbackTimeInfo* timeInfo,
+                        PaStreamCallbackFlags statusFlags,
+                        void *userData )
+{
+    int i;
+    LoopbackContext *loopbackContext = (LoopbackContext *) userData;
+
+
+    loopbackContext->callbackCount += 1;
+    if( statusFlags & paInputUnderflow ) loopbackContext->inputUnderflowCount += 1;
+    if( statusFlags & paInputOverflow ) loopbackContext->inputOverflowCount += 1;
+    if( statusFlags & paOutputUnderflow ) loopbackContext->outputUnderflowCount += 1;
+    if( statusFlags & paOutputOverflow ) loopbackContext->outputOverflowCount += 1;
+    if( statusFlags & paPrimingOutput ) loopbackContext->primingCount += 1;
+    if( framesPerBuffer > loopbackContext->maxFramesPerBuffer )
+    {
+        loopbackContext->maxFramesPerBuffer = framesPerBuffer;
+    }
+    if( framesPerBuffer < loopbackContext->minFramesPerBuffer )
+    {
+        loopbackContext->minFramesPerBuffer = framesPerBuffer;
+    }
+
+    /* This may get called with NULL inputBuffer during initial setup.
+     * We may also use the same callback with output only streams.
+     */
+    if( inputBuffer != NULL)
+    {
+        int channelsPerFrame = loopbackContext->test->inputParameters.channelCount;
+        float *in = (float *)inputBuffer;
+        PaSampleFormat inFormat = loopbackContext->test->inputParameters.sampleFormat;
+
+        loopbackContext->inputBufferCount += 1;
+
+        if( inFormat != paFloat32 )
+        {
+            int samplesToConvert = framesPerBuffer * channelsPerFrame;
+            in = (float *) g_ConversionBuffer;
+            if( samplesToConvert > MAX_CONVERSION_SAMPLES )
+            {
+                // Hack to prevent buffer overflow.
+                // @todo Loop with small buffer instead of failing.
+                printf("Format conversion buffer too small!\n");
+                return paComplete;
+            }
+            PaQa_ConvertToFloat( inputBuffer, samplesToConvert, inFormat, (float *) g_ConversionBuffer );
+        }
+
+        // Read each channel from the buffer.
+        for( i=0; i<channelsPerFrame; i++ )
+        {
+            loopbackContext->done |= PaQa_WriteRecording( &loopbackContext->recordings[i],
+                                        in + i,
+                                        framesPerBuffer,
+                                        channelsPerFrame );
+        }
+    }
+
+    if( outputBuffer != NULL )
+    {
+        int channelsPerFrame = loopbackContext->test->outputParameters.channelCount;
+        float *out = (float *)outputBuffer;
+        PaSampleFormat outFormat = loopbackContext->test->outputParameters.sampleFormat;
+
+        loopbackContext->outputBufferCount += 1;
+
+        if( outFormat != paFloat32 )
+        {
+            // If we need to convert then mix to the g_ConversionBuffer and then convert into the PA outputBuffer.
+            out = (float *) g_ConversionBuffer;
+        }
+
+        PaQa_EraseBuffer( out, framesPerBuffer, channelsPerFrame );
+        for( i=0; i<channelsPerFrame; i++ )
+        {
+            PaQa_MixSine( &loopbackContext->generators[i],
+                         out + i,
+                         framesPerBuffer,
+                         channelsPerFrame );
+        }
+
+        if( outFormat != paFloat32 )
+        {
+            int samplesToConvert = framesPerBuffer * channelsPerFrame;
+            if( samplesToConvert > MAX_CONVERSION_SAMPLES )
+            {
+                printf("Format conversion buffer too small!\n");
+                return paComplete;
+            }
+            PaQa_ConvertFromFloat( out, framesPerBuffer * channelsPerFrame, outFormat, outputBuffer );
+        }
+
+    }
+
+    // Measure whether the input or output are lagging behind.
+    // Don't measure lag at end.
+    if( !loopbackContext->done )
+    {
+        int inputOutputDelta = loopbackContext->inputBufferCount - loopbackContext->outputBufferCount;
+        if( loopbackContext->maxInputOutputDelta < inputOutputDelta )
+        {
+            loopbackContext->maxInputOutputDelta = inputOutputDelta;
+        }
+        if( loopbackContext->minInputOutputDelta > inputOutputDelta )
+        {
+            loopbackContext->minInputOutputDelta = inputOutputDelta;
+        }
+    }
+
+    return loopbackContext->done ? paComplete : paContinue;
+}
+
+static void CopyStreamInfoToLoopbackContext( LoopbackContext *loopbackContext, PaStream *inputStream, PaStream *outputStream )
+{
+    const PaStreamInfo *inputStreamInfo = Pa_GetStreamInfo( inputStream );
+    const PaStreamInfo *outputStreamInfo = Pa_GetStreamInfo( outputStream );
+
+    loopbackContext->streamInfoInputLatency = inputStreamInfo ? inputStreamInfo->inputLatency : -1;
+    loopbackContext->streamInfoOutputLatency = outputStreamInfo ? outputStreamInfo->outputLatency : -1;
+}
+
+/*******************************************************************/
+/**
+ * Open a full duplex audio stream.
+ * Generate sine waves on the output channels and record the input channels.
+ * Then close the stream.
+ * @return 0 if OK or negative error.
+ */
+int PaQa_RunLoopbackFullDuplex( LoopbackContext *loopbackContext )
+{
+    PaStream *stream = NULL;
+    PaError err = 0;
+    TestParameters *test = loopbackContext->test;
+    loopbackContext->done = 0;
+    // Use one full duplex stream.
+    err = Pa_OpenStream(
+                    &stream,
+                    &test->inputParameters,
+                    &test->outputParameters,
+                    test->sampleRate,
+                    test->framesPerBuffer,
+                    paClipOff, /* we won't output out of range samples so don't bother clipping them */
+                    RecordAndPlaySinesCallback,
+                    loopbackContext );
+    if( err != paNoError ) goto error;
+
+    CopyStreamInfoToLoopbackContext( loopbackContext, stream, stream );
+
+    err = Pa_StartStream( stream );
+    if( err != paNoError ) goto error;
+
+    // Wait for stream to finish.
+    while( loopbackContext->done == 0 )
+    {
+        Pa_Sleep(PAQA_WAIT_STREAM_MSEC);
+    }
+
+    err = Pa_StopStream( stream );
+    if( err != paNoError ) goto error;
+
+    err = Pa_CloseStream( stream );
+    if( err != paNoError ) goto error;
+
+    return 0;
+
+error:
+    return err;
+}
+
+/*******************************************************************/
+/**
+ * Open two audio streams, one for input and one for output.
+ * Generate sine waves on the output channels and record the input channels.
+ * Then close the stream.
+ * @return 0 if OK or paTimedOut.
+ */
+
+int PaQa_WaitForStream( LoopbackContext *loopbackContext )
+{
+    int timeoutMSec = 1000 * PAQA_TEST_DURATION * 2;
+
+    // Wait for stream to finish or timeout.
+    while( (loopbackContext->done == 0) && (timeoutMSec > 0) )
+    {
+        Pa_Sleep(PAQA_WAIT_STREAM_MSEC);
+        timeoutMSec -= PAQA_WAIT_STREAM_MSEC;
+    }
+
+    if( loopbackContext->done == 0 )
+    {
+        printf("ERROR - stream completion timed out!");
+        return paTimedOut;
+    }
+    return 0;
+}
+
+/*******************************************************************/
+/**
+ * Open two audio streams, one for input and one for output.
+ * Generate sine waves on the output channels and record the input channels.
+ * Then close the stream.
+ * @return 0 if OK or negative error.
+ */
+int PaQa_RunLoopbackHalfDuplex( LoopbackContext *loopbackContext )
+{
+    PaStream *inStream = NULL;
+    PaStream *outStream = NULL;
+    PaError err = 0;
+    int timedOut = 0;
+    TestParameters *test = loopbackContext->test;
+    loopbackContext->done = 0;
+
+    // Use two half duplex streams.
+    err = Pa_OpenStream(
+                        &inStream,
+                        &test->inputParameters,
+                        NULL,
+                        test->sampleRate,
+                        test->framesPerBuffer,
+                        test->streamFlags,
+                        RecordAndPlaySinesCallback,
+                        loopbackContext );
+    if( err != paNoError ) goto error;
+    err = Pa_OpenStream(
+                        &outStream,
+                        NULL,
+                        &test->outputParameters,
+                        test->sampleRate,
+                        test->framesPerBuffer,
+                        test->streamFlags,
+                        RecordAndPlaySinesCallback,
+                        loopbackContext );
+    if( err != paNoError ) goto error;
+
+    CopyStreamInfoToLoopbackContext( loopbackContext, inStream, outStream );
+
+    err = Pa_StartStream( inStream );
+    if( err != paNoError ) goto error;
+
+    // Start output later so we catch the beginning of the waveform.
+    err = Pa_StartStream( outStream );
+    if( err != paNoError ) goto error;
+
+    timedOut = PaQa_WaitForStream( loopbackContext );
+
+    err = Pa_StopStream( inStream );
+    if( err != paNoError ) goto error;
+
+    err = Pa_StopStream( outStream );
+    if( err != paNoError ) goto error;
+
+    err = Pa_CloseStream( inStream );
+    if( err != paNoError ) goto error;
+
+    err = Pa_CloseStream( outStream );
+    if( err != paNoError ) goto error;
+
+    return timedOut;
+
+error:
+    return err;
+}
+
+
+/*******************************************************************/
+/**
+ * Open one audio streams, just for input.
+ * Record background level.
+ * Then close the stream.
+ * @return 0 if OK or negative error.
+ */
+int PaQa_RunInputOnly( LoopbackContext *loopbackContext )
+{
+    PaStream *inStream = NULL;
+    PaError err = 0;
+    int timedOut = 0;
+    TestParameters *test = loopbackContext->test;
+    loopbackContext->done = 0;
+
+    // Just open an input stream.
+    err = Pa_OpenStream(
+                        &inStream,
+                        &test->inputParameters,
+                        NULL,
+                        test->sampleRate,
+                        test->framesPerBuffer,
+                        paClipOff, /* We won't output out of range samples so don't bother clipping them. */
+                        RecordAndPlaySinesCallback,
+                        loopbackContext );
+    if( err != paNoError ) goto error;
+
+    err = Pa_StartStream( inStream );
+    if( err != paNoError ) goto error;
+
+    timedOut = PaQa_WaitForStream( loopbackContext );
+
+    err = Pa_StopStream( inStream );
+    if( err != paNoError ) goto error;
+
+    err = Pa_CloseStream( inStream );
+    if( err != paNoError ) goto error;
+
+    return timedOut;
+
+error:
+    return err;
+}
+
+/*******************************************************************/
+static int RecordAndPlayBlockingIO( PaStream *inStream,
+                                      PaStream *outStream,
+                                      LoopbackContext *loopbackContext
+                                      )
+{
+    int i;
+    float *in = (float *)g_ReadWriteBuffer;
+    float *out = (float *)g_ReadWriteBuffer;
+    PaError err;
+    int done = 0;
+    long available;
+    const long maxPerBuffer = 64;
+    TestParameters *test = loopbackContext->test;
+    long framesPerBuffer = test->framesPerBuffer;
+    if( framesPerBuffer <= 0 )
+    {
+        framesPerBuffer = maxPerBuffer; // bigger values might run past end of recording
+    }
+
+    // Read in audio.
+    err = Pa_ReadStream( inStream, in, framesPerBuffer );
+    // Ignore an overflow on the first read.
+    //if( !((loopbackContext->callbackCount == 0) && (err == paInputOverflowed)) )
+    if( err != paInputOverflowed )
+    {
+        QA_ASSERT_EQUALS( "Pa_ReadStream failed", paNoError, err );
+    }
+    else
+    {
+        loopbackContext->inputOverflowCount += 1;
+    }
+
+
+    // Save in a recording.
+    for( i=0; i<loopbackContext->test->inputParameters.channelCount; i++ )
+    {
+        done |= PaQa_WriteRecording( &loopbackContext->recordings[i],
+                 in + i,
+                 framesPerBuffer,
+                 loopbackContext->test->inputParameters.channelCount );
+    }
+
+    // Synthesize audio.
+    available = Pa_GetStreamWriteAvailable( outStream );
+    if( available > (2*framesPerBuffer) ) available = (2*framesPerBuffer);
+    PaQa_EraseBuffer( out, available, loopbackContext->test->outputParameters.channelCount );
+    for( i=0; i<loopbackContext->test->outputParameters.channelCount; i++ )
+    {
+        PaQa_MixSine( &loopbackContext->generators[i],
+                  out + i,
+                  available,
+                  loopbackContext->test->outputParameters.channelCount );
+    }
+
+    // Write out audio.
+    err = Pa_WriteStream( outStream, out, available );
+    // Ignore an underflow on the first write.
+    //if( !((loopbackContext->callbackCount == 0) && (err == paOutputUnderflowed)) )
+    if( err != paOutputUnderflowed )
+    {
+        QA_ASSERT_EQUALS( "Pa_WriteStream failed", paNoError, err );
+    }
+    else
+    {
+        loopbackContext->outputUnderflowCount += 1;
+    }
+
+
+    loopbackContext->callbackCount += 1;
+
+    return done;
+error:
+    return err;
+}
+
+
+/*******************************************************************/
+/**
+ * Open two audio streams with non-blocking IO.
+ * Generate sine waves on the output channels and record the input channels.
+ * Then close the stream.
+ * @return 0 if OK or negative error.
+ */
+int PaQa_RunLoopbackHalfDuplexBlockingIO( LoopbackContext *loopbackContext )
+{
+    PaStream *inStream = NULL;
+    PaStream *outStream = NULL;
+    PaError err = 0;
+    TestParameters *test = loopbackContext->test;
+
+    // Use two half duplex streams.
+    err = Pa_OpenStream(
+                        &inStream,
+                        &test->inputParameters,
+                        NULL,
+                        test->sampleRate,
+                        test->framesPerBuffer,
+                        paClipOff, /* we won't output out of range samples so don't bother clipping them */
+                        NULL, // causes non-blocking IO
+                        NULL );
+    if( err != paNoError ) goto error1;
+    err = Pa_OpenStream(
+                        &outStream,
+                        NULL,
+                        &test->outputParameters,
+                        test->sampleRate,
+                        test->framesPerBuffer,
+                        paClipOff, /* we won't output out of range samples so don't bother clipping them */
+                        NULL, // causes non-blocking IO
+                        NULL );
+    if( err != paNoError ) goto error2;
+
+    CopyStreamInfoToLoopbackContext( loopbackContext, inStream, outStream );
+
+    err = Pa_StartStream( outStream );
+    if( err != paNoError ) goto error3;
+
+    err = Pa_StartStream( inStream );
+    if( err != paNoError ) goto error3;
+
+    while( err == 0 )
+    {
+        err = RecordAndPlayBlockingIO( inStream, outStream, loopbackContext );
+        if( err < 0 ) goto error3;
+    }
+
+    err = Pa_StopStream( inStream );
+    if( err != paNoError ) goto error3;
+
+    err = Pa_StopStream( outStream );
+    if( err != paNoError ) goto error3;
+
+    err = Pa_CloseStream( outStream );
+    if( err != paNoError ) goto error2;
+
+    err = Pa_CloseStream( inStream );
+    if( err != paNoError ) goto error1;
+
+
+    return 0;
+
+error3:
+    Pa_CloseStream( outStream );
+error2:
+    Pa_CloseStream( inStream );
+error1:
+    return err;
+}
+
+
+/*******************************************************************/
+/**
+ * Open one audio stream with non-blocking IO.
+ * Generate sine waves on the output channels and record the input channels.
+ * Then close the stream.
+ * @return 0 if OK or negative error.
+ */
+int PaQa_RunLoopbackFullDuplexBlockingIO( LoopbackContext *loopbackContext )
+{
+    PaStream *stream = NULL;
+    PaError err = 0;
+    TestParameters *test = loopbackContext->test;
+
+    // Use one full duplex stream.
+    err = Pa_OpenStream(
+                        &stream,
+                        &test->inputParameters,
+                        &test->outputParameters,
+                        test->sampleRate,
+                        test->framesPerBuffer,
+                        paClipOff, /* we won't output out of range samples so don't bother clipping them */
+                        NULL, // causes non-blocking IO
+                        NULL );
+    if( err != paNoError ) goto error1;
+
+    CopyStreamInfoToLoopbackContext( loopbackContext, stream, stream );
+
+    err = Pa_StartStream( stream );
+    if( err != paNoError ) goto error2;
+
+    while( err == 0 )
+    {
+        err = RecordAndPlayBlockingIO( stream, stream, loopbackContext );
+        if( err < 0 ) goto error2;
+    }
+
+    err = Pa_StopStream( stream );
+    if( err != paNoError ) goto error2;
+
+
+    err = Pa_CloseStream( stream );
+    if( err != paNoError ) goto error1;
+
+
+    return 0;
+
+error2:
+    Pa_CloseStream( stream );
+error1:
+    return err;
+}
+
+
+/*******************************************************************/
+/**
+ * Run some kind of loopback test.
+ * @return 0 if OK or negative error.
+ */
+int PaQa_RunLoopback( LoopbackContext *loopbackContext )
+{
+    PaError err = 0;
+    TestParameters *test = loopbackContext->test;
+
+
+    if( test->flags & PAQA_FLAG_TWO_STREAMS )
+    {
+        if( test->flags & PAQA_FLAG_USE_BLOCKING_IO )
+        {
+            err = PaQa_RunLoopbackHalfDuplexBlockingIO( loopbackContext );
+        }
+        else
+        {
+            err = PaQa_RunLoopbackHalfDuplex( loopbackContext );
+        }
+    }
+    else
+    {
+        if( test->flags & PAQA_FLAG_USE_BLOCKING_IO )
+        {
+            err = PaQa_RunLoopbackFullDuplexBlockingIO( loopbackContext );
+        }
+        else
+        {
+            err = PaQa_RunLoopbackFullDuplex( loopbackContext );
+        }
+    }
+
+    if( err != paNoError )
+    {
+        printf("PortAudio error = %s\n", Pa_GetErrorText( err ) );
+    }
+    return err;
+}
+
+/*******************************************************************/
+static int PaQa_SaveTestResultToWaveFile( UserOptions *userOptions, PaQaRecording *recording )
+{
+    if( userOptions->saveBadWaves )
+    {
+        char filename[256];
+#ifdef WIN32
+        _snprintf( filename, sizeof(filename), "%s\\paloopback_%d.wav", userOptions->waveFilePath, userOptions->waveFileCount++ );
+#else
+        snprintf( filename, sizeof(filename), "%s/paloopback_%d.wav", userOptions->waveFilePath, userOptions->waveFileCount++ );
+#endif
+        printf( "\"%s\", ", filename );
+        return PaQa_SaveRecordingToWaveFile( recording, filename );
+    }
+    return 0;
+}
+
+/*******************************************************************/
+static int PaQa_SetupLoopbackContext( LoopbackContext *loopbackContextPtr, TestParameters *testParams )
+{
+    int i;
+    // Setup loopback context.
+    memset( loopbackContextPtr, 0, sizeof(LoopbackContext) );
+    loopbackContextPtr->test = testParams;
+    for( i=0; i<testParams->samplesPerFrame; i++ )
+    {
+        int err = PaQa_InitializeRecording( &loopbackContextPtr->recordings[i], testParams->maxFrames, testParams->sampleRate );
+        QA_ASSERT_EQUALS( "PaQa_InitializeRecording failed", paNoError, err );
+    }
+    for( i=0; i<testParams->samplesPerFrame; i++ )
+    {
+        PaQa_SetupSineGenerator( &loopbackContextPtr->generators[i], PaQa_GetNthFrequency( testParams->baseFrequency, i ),
+                                testParams->amplitude, testParams->sampleRate );
+    }
+    loopbackContextPtr->minFramesPerBuffer = 0x0FFFFFFF;
+    return 0;
+error:
+    return -1;
+}
+
+/*******************************************************************/
+static void PaQa_TeardownLoopbackContext( LoopbackContext *loopbackContextPtr )
+{
+    int i;
+    if( loopbackContextPtr->test != NULL )
+    {
+        for( i=0; i<loopbackContextPtr->test->samplesPerFrame; i++ )
+        {
+            PaQa_TerminateRecording( &loopbackContextPtr->recordings[i] );
+        }
+    }
+}
+
+/*******************************************************************/
+static void PaQa_PrintShortErrorReport( PaQaAnalysisResult *analysisResultPtr, int channel )
+{
+    printf("channel %d ", channel);
+    if( analysisResultPtr->popPosition > 0 )
+    {
+        printf("POP %0.3f at %d, ", (double)analysisResultPtr->popAmplitude, (int)analysisResultPtr->popPosition );
+    }
+    else
+    {
+        if( analysisResultPtr->addedFramesPosition > 0 )
+        {
+            printf("ADD %d at %d ", (int)analysisResultPtr->numAddedFrames, (int)analysisResultPtr->addedFramesPosition );
+        }
+
+        if( analysisResultPtr->droppedFramesPosition > 0 )
+        {
+            printf("DROP %d at %d ", (int)analysisResultPtr->numDroppedFrames, (int)analysisResultPtr->droppedFramesPosition );
+        }
+    }
+}
+
+/*******************************************************************/
+static void PaQa_PrintFullErrorReport( PaQaAnalysisResult *analysisResultPtr, int channel )
+{
+    printf("\n=== Loopback Analysis ===================\n");
+    printf("             channel: %d\n", channel );
+    printf("             latency: %10.3f\n", analysisResultPtr->latency );
+    printf("      amplitudeRatio: %10.3f\n", (double)analysisResultPtr->amplitudeRatio );
+    printf("         popPosition: %10.3f\n", (double)analysisResultPtr->popPosition );
+    printf("        popAmplitude: %10.3f\n", (double)analysisResultPtr->popAmplitude );
+    printf("    num added frames: %10.3f\n", analysisResultPtr->numAddedFrames );
+    printf("     added frames at: %10.3f\n", analysisResultPtr->addedFramesPosition );
+    printf("  num dropped frames: %10.3f\n", analysisResultPtr->numDroppedFrames );
+    printf("   dropped frames at: %10.3f\n", analysisResultPtr->droppedFramesPosition );
+}
+
+/*******************************************************************/
+/**
+ * Test loopback connection using the given parameters.
+ * @return number of channels with glitches, or negative error.
+ */
+static int PaQa_SingleLoopBackTest( UserOptions *userOptions, TestParameters *testParams )
+{
+    int i;
+    LoopbackContext loopbackContext;
+    PaError err = paNoError;
+    PaQaTestTone testTone;
+    PaQaAnalysisResult analysisResult;
+    int numBadChannels = 0;
+
+    printf("| %5d | %6d | ", ((int)(testParams->sampleRate+0.5)), testParams->framesPerBuffer );
+    fflush(stdout);
+
+    testTone.samplesPerFrame = testParams->samplesPerFrame;
+    testTone.sampleRate = testParams->sampleRate;
+    testTone.amplitude = testParams->amplitude;
+    testTone.startDelay = 0;
+
+    err = PaQa_SetupLoopbackContext( &loopbackContext, testParams );
+    if( err ) return err;
+
+    err = PaQa_RunLoopback( &loopbackContext );
+    QA_ASSERT_TRUE("loopback did not run", (loopbackContext.callbackCount > 1) );
+
+    printf( "%7.2f %7.2f %7.2f | ",
+           loopbackContext.streamInfoInputLatency * 1000.0,
+           loopbackContext.streamInfoOutputLatency * 1000.0,
+           (loopbackContext.streamInfoInputLatency + loopbackContext.streamInfoOutputLatency) * 1000.0
+           );
+
+    printf( "%4d/%4d/%4d, %4d/%4d/%4d | ",
+           loopbackContext.inputOverflowCount,
+           loopbackContext.inputUnderflowCount,
+           loopbackContext.inputBufferCount,
+           loopbackContext.outputOverflowCount,
+           loopbackContext.outputUnderflowCount,
+           loopbackContext.outputBufferCount
+           );
+
+    // Analyse recording to detect glitches.
+    for( i=0; i<testParams->samplesPerFrame; i++ )
+    {
+        double freq = PaQa_GetNthFrequency( testParams->baseFrequency, i );
+        testTone.frequency = freq;
+
+        PaQa_AnalyseRecording(  &loopbackContext.recordings[i], &testTone, &analysisResult );
+
+        if( i==0 )
+        {
+            double latencyMSec;
+
+            printf( "%4d-%4d | ",
+                   loopbackContext.minFramesPerBuffer,
+                   loopbackContext.maxFramesPerBuffer
+                   );
+
+            latencyMSec = 1000.0 * analysisResult.latency / testParams->sampleRate;
+            printf("%7.2f | ", latencyMSec );
+
+        }
+
+        if( analysisResult.valid )
+        {
+            int badChannel = ( (analysisResult.popPosition > 0)
+                       || (analysisResult.addedFramesPosition > 0)
+                       || (analysisResult.droppedFramesPosition > 0) );
+
+            if( badChannel )
+            {
+                if( userOptions->verbose )
+                {
+                    PaQa_PrintFullErrorReport( &analysisResult, i );
+                }
+                else
+                {
+                    PaQa_PrintShortErrorReport( &analysisResult, i );
+                }
+                PaQa_SaveTestResultToWaveFile( userOptions, &loopbackContext.recordings[i] );
+            }
+            numBadChannels += badChannel;
+        }
+        else
+        {
+            printf( "[%d] No or low signal, ampRatio = %f", i, analysisResult.amplitudeRatio );
+            numBadChannels += 1;
+        }
+
+    }
+    if( numBadChannels == 0 )
+    {
+        printf( "OK" );
+    }
+
+    // Print the # errors so far to make it easier to see where the error occurred.
+    printf( " - #errs = %d\n", g_testsFailed );
+
+    PaQa_TeardownLoopbackContext( &loopbackContext );
+    if( numBadChannels > 0 )
+    {
+        g_testsFailed += 1;
+    }
+    return numBadChannels;
+
+error:
+    PaQa_TeardownLoopbackContext( &loopbackContext );
+    printf( "\n" );
+    g_testsFailed += 1;
+    return err;
+}
+
+/*******************************************************************/
+static void PaQa_SetDefaultTestParameters( TestParameters *testParamsPtr, PaDeviceIndex inputDevice, PaDeviceIndex outputDevice )
+{
+    memset( testParamsPtr, 0, sizeof(TestParameters) );
+
+    testParamsPtr->samplesPerFrame = 2;
+    testParamsPtr->amplitude = 0.5;
+    testParamsPtr->sampleRate = 44100;
+    testParamsPtr->maxFrames = (int) (PAQA_TEST_DURATION * testParamsPtr->sampleRate);
+    testParamsPtr->framesPerBuffer = DEFAULT_FRAMES_PER_BUFFER;
+    testParamsPtr->baseFrequency = 200.0;
+    testParamsPtr->flags = PAQA_FLAG_TWO_STREAMS;
+    testParamsPtr->streamFlags = paClipOff; /* we won't output out of range samples so don't bother clipping them */
+
+    testParamsPtr->inputParameters.device = inputDevice;
+    testParamsPtr->inputParameters.sampleFormat = paFloat32;
+    testParamsPtr->inputParameters.channelCount = testParamsPtr->samplesPerFrame;
+    testParamsPtr->inputParameters.suggestedLatency = Pa_GetDeviceInfo( inputDevice )->defaultLowInputLatency;
+    //testParamsPtr->inputParameters.suggestedLatency = Pa_GetDeviceInfo( inputDevice )->defaultHighInputLatency;
+
+    testParamsPtr->outputParameters.device = outputDevice;
+    testParamsPtr->outputParameters.sampleFormat = paFloat32;
+    testParamsPtr->outputParameters.channelCount = testParamsPtr->samplesPerFrame;
+    testParamsPtr->outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputDevice )->defaultLowOutputLatency;
+    //testParamsPtr->outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputDevice )->defaultHighOutputLatency;
+}
+
+/*******************************************************************/
+static void PaQa_OverrideTestParameters( TestParameters *testParamsPtr,  UserOptions *userOptions )
+{
+    // Check to see if a specific value was requested.
+    if( userOptions->sampleRate >= 0 )
+    {
+        testParamsPtr->sampleRate = userOptions->sampleRate;
+        testParamsPtr->maxFrames = (int) (PAQA_TEST_DURATION * testParamsPtr->sampleRate);
+    }
+    if( userOptions->framesPerBuffer >= 0 )
+    {
+        testParamsPtr->framesPerBuffer = userOptions->framesPerBuffer;
+    }
+    if( userOptions->inputLatency >= 0 )
+    {
+        testParamsPtr->inputParameters.suggestedLatency = userOptions->inputLatency * 0.001;
+    }
+    if( userOptions->outputLatency >= 0 )
+    {
+        testParamsPtr->outputParameters.suggestedLatency = userOptions->outputLatency * 0.001;
+    }
+    printf( "   Running with suggested latency (msec): input = %5.2f, out = %5.2f\n",
+        (testParamsPtr->inputParameters.suggestedLatency * 1000.0),
+        (testParamsPtr->outputParameters.suggestedLatency * 1000.0) );
+}
+
+/*******************************************************************/
+/**
+ * Run a series of tests on this loopback connection.
+ * @return number of bad channel results
+ */
+static int PaQa_AnalyzeLoopbackConnection( UserOptions *userOptions, PaDeviceIndex inputDevice, PaDeviceIndex outputDevice )
+{
+    int iFlags;
+    int iRate;
+    int iSize;
+    int iFormat;
+    int savedValue;
+    TestParameters testParams;
+    const PaDeviceInfo *inputDeviceInfo = Pa_GetDeviceInfo( inputDevice );
+    const PaDeviceInfo *outputDeviceInfo = Pa_GetDeviceInfo( outputDevice );
+    int totalBadChannels = 0;
+
+    // test half duplex first because it is more likely to work.
+    int flagSettings[] = { PAQA_FLAG_TWO_STREAMS, 0 };
+    int numFlagSettings = (sizeof(flagSettings)/sizeof(int));
+
+    double sampleRates[] = { 8000.0, 11025.0, 16000.0, 22050.0, 32000.0, 44100.0, 48000.0, 96000.0 };
+    int numRates = (sizeof(sampleRates)/sizeof(double));
+
+    // framesPerBuffer==0 means PA decides on the buffer size.
+    int framesPerBuffers[] = { 0, 16, 32, 40, 64, 100, 128, 256, 512, 1024 };
+    int numBufferSizes = (sizeof(framesPerBuffers)/sizeof(int));
+
+    PaSampleFormat sampleFormats[] = { paFloat32, paUInt8, paInt8, paInt16, paInt32 };
+    const char *sampleFormatNames[] = { "paFloat32", "paUInt8", "paInt8", "paInt16", "paInt32" };
+    int numSampleFormats = (sizeof(sampleFormats)/sizeof(PaSampleFormat));
+
+    printf( "=============== Analysing Loopback %d to %d =====================\n", outputDevice, inputDevice  );
+    printf( "   Devices: %s => %s\n", outputDeviceInfo->name, inputDeviceInfo->name);
+
+    PaQa_SetDefaultTestParameters( &testParams, inputDevice, outputDevice );
+
+    PaQa_OverrideTestParameters( &testParams, userOptions );
+
+    // Loop though combinations of audio parameters.
+    for( iFlags=0; iFlags<numFlagSettings; iFlags++ )
+    {
+        int numRuns = 0;
+
+        testParams.flags = flagSettings[iFlags];
+        printf( "\n************ Mode = %s ************\n",
+               (( testParams.flags & 1 ) ? s_FlagOnNames[0] : s_FlagOffNames[0]) );
+
+        printf("|-   requested  -|-  stream info latency  -|- measured ------------------------------\n");
+        printf("|-sRate-|-fr/buf-|- in    - out   - total -|- over/under/calls for in, out -|- frm/buf -|-latency-|- channel results -\n");
+
+        // Loop though various sample rates.
+        if( userOptions->sampleRate < 0 )
+        {
+            savedValue = testParams.sampleRate;
+            for( iRate=0; iRate<numRates; iRate++ )
+            {
+                int numBadChannels;
+
+                // SAMPLE RATE
+                testParams.sampleRate = sampleRates[iRate];
+                testParams.maxFrames = (int) (PAQA_TEST_DURATION * testParams.sampleRate);
+
+                numBadChannels = PaQa_SingleLoopBackTest( userOptions, &testParams );
+                totalBadChannels += numBadChannels;
+            }
+            testParams.sampleRate = savedValue;
+            testParams.maxFrames = (int) (PAQA_TEST_DURATION * testParams.sampleRate);
+            printf( "\n" );
+            numRuns += 1;
+        }
+
+        // Loop through various buffer sizes.
+        if( userOptions->framesPerBuffer < 0 )
+        {
+            savedValue = testParams.framesPerBuffer;
+            for( iSize=0; iSize<numBufferSizes; iSize++ )
+            {
+                int numBadChannels;
+
+                // BUFFER SIZE
+                testParams.framesPerBuffer = framesPerBuffers[iSize];
+
+                numBadChannels = PaQa_SingleLoopBackTest( userOptions, &testParams );
+                totalBadChannels += numBadChannels;
+            }
+            testParams.framesPerBuffer = savedValue;
+            printf( "\n" );
+            numRuns += 1;
+        }
+        // Run one with single parameters in case we did not do a series.
+        if( numRuns == 0 )
+        {
+            int numBadChannels = PaQa_SingleLoopBackTest( userOptions, &testParams );
+            totalBadChannels += numBadChannels;
+        }
+    }
+
+    printf("\nTest Sample Formats using Half Duplex IO -----\n" );
+
+    PaQa_SetDefaultTestParameters( &testParams, inputDevice, outputDevice );
+    testParams.flags = PAQA_FLAG_TWO_STREAMS;
+    for( iFlags= 0; iFlags<4; iFlags++ )
+    {
+        // Cycle through combinations of flags.
+        testParams.streamFlags = 0;
+        if( iFlags & 1 ) testParams.streamFlags |= paClipOff;
+        if( iFlags & 2 ) testParams.streamFlags |= paDitherOff;
+
+        for( iFormat=0; iFormat<numSampleFormats; iFormat++ )
+        {
+            int numBadChannels;
+            PaSampleFormat format = sampleFormats[ iFormat ];
+            testParams.inputParameters.sampleFormat = format;
+            testParams.outputParameters.sampleFormat = format;
+            printf("Sample format = %d = %s, PaStreamFlags = 0x%02X\n", (int) format, sampleFormatNames[iFormat], (unsigned int) testParams.streamFlags );
+            numBadChannels = PaQa_SingleLoopBackTest( userOptions, &testParams );
+            totalBadChannels += numBadChannels;
+        }
+    }
+    printf( "\n" );
+    printf( "****************************************\n");
+
+    return totalBadChannels;
+}
+
+/*******************************************************************/
+int PaQa_CheckForClippedLoopback( LoopbackContext *loopbackContextPtr )
+{
+    int clipped = 0;
+    TestParameters *testParamsPtr = loopbackContextPtr->test;
+
+    // Start in the middle assuming past latency.
+    int startFrame = testParamsPtr->maxFrames/2;
+    int numFrames = testParamsPtr->maxFrames/2;
+
+    // Check to see if the signal is clipped.
+    double amplitudeLeft = PaQa_MeasureSineAmplitudeBySlope( &loopbackContextPtr->recordings[0],
+                                                            testParamsPtr->baseFrequency, testParamsPtr->sampleRate,
+                                                            startFrame, numFrames );
+    double gainLeft = amplitudeLeft / testParamsPtr->amplitude;
+    double amplitudeRight = PaQa_MeasureSineAmplitudeBySlope( &loopbackContextPtr->recordings[1],
+                                                             testParamsPtr->baseFrequency, testParamsPtr->sampleRate,
+                                                             startFrame, numFrames );
+    double gainRight = amplitudeLeft / testParamsPtr->amplitude;
+    printf("   Loop gain: left = %f, right = %f\n", gainLeft, gainRight );
+
+    if( (amplitudeLeft > 1.0 ) || (amplitudeRight > 1.0) )
+    {
+        printf("ERROR - loop gain is too high. Should be around than 1.0. Please lower output level and/or input gain.\n" );
+        clipped = 1;
+    }
+    return clipped;
+}
+
+/*******************************************************************/
+int PaQa_MeasureBackgroundNoise( LoopbackContext *loopbackContextPtr, double *rmsPtr )
+{
+    int result = 0;
+    *rmsPtr = 0.0;
+    // Rewind so we can record some input.
+    loopbackContextPtr->recordings[0].numFrames = 0;
+    loopbackContextPtr->recordings[1].numFrames = 0;
+    result = PaQa_RunInputOnly( loopbackContextPtr );
+    if( result == 0 )
+    {
+        double leftRMS = PaQa_MeasureRootMeanSquare( loopbackContextPtr->recordings[0].buffer,
+                                                    loopbackContextPtr->recordings[0].numFrames );
+        double rightRMS = PaQa_MeasureRootMeanSquare( loopbackContextPtr->recordings[1].buffer,
+                                                     loopbackContextPtr->recordings[1].numFrames );
+        *rmsPtr = (leftRMS + rightRMS) / 2.0;
+    }
+    return result;
+}
+
+/*******************************************************************/
+/**
+ * Output a sine wave then try to detect it on input.
+ *
+ * @return 1 if loopback connected, 0 if not, or negative error.
+ */
+int PaQa_CheckForLoopBack( UserOptions *userOptions, PaDeviceIndex inputDevice, PaDeviceIndex outputDevice )
+{
+    TestParameters testParams;
+    LoopbackContext loopbackContext;
+    const PaDeviceInfo *inputDeviceInfo;
+    const PaDeviceInfo *outputDeviceInfo;
+    PaError err = paNoError;
+    double minAmplitude;
+    int loopbackIsConnected;
+    int startFrame, numFrames;
+    double magLeft, magRight;
+
+    inputDeviceInfo = Pa_GetDeviceInfo( inputDevice );
+    if( inputDeviceInfo == NULL )
+    {
+        printf("ERROR - Pa_GetDeviceInfo for input returned NULL.\n");
+        return paInvalidDevice;
+    }
+    if( inputDeviceInfo->maxInputChannels < 2 )
+    {
+        return 0;
+    }
+
+    outputDeviceInfo = Pa_GetDeviceInfo( outputDevice );
+    if( outputDeviceInfo == NULL )
+    {
+        printf("ERROR - Pa_GetDeviceInfo for output returned NULL.\n");
+        return paInvalidDevice;
+    }
+    if( outputDeviceInfo->maxOutputChannels < 2 )
+    {
+        return 0;
+    }
+
+    printf( "Look for loopback cable between \"%s\" => \"%s\"\n", outputDeviceInfo->name, inputDeviceInfo->name);
+
+    printf( "   Default suggested input latency (msec): low = %5.2f, high = %5.2f\n",
+        (inputDeviceInfo->defaultLowInputLatency * 1000.0),
+        (inputDeviceInfo->defaultHighInputLatency * 1000.0) );
+    printf( "   Default suggested output latency (msec): low = %5.2f, high = %5.2f\n",
+        (outputDeviceInfo->defaultLowOutputLatency * 1000.0),
+        (outputDeviceInfo->defaultHighOutputLatency * 1000.0) );
+
+    PaQa_SetDefaultTestParameters( &testParams, inputDevice, outputDevice );
+
+    PaQa_OverrideTestParameters( &testParams, userOptions );
+
+    testParams.maxFrames = (int) (LOOPBACK_DETECTION_DURATION_SECONDS * testParams.sampleRate);
+    minAmplitude = testParams.amplitude / 4.0;
+
+    // Check to see if the selected formats are supported.
+    if( Pa_IsFormatSupported( &testParams.inputParameters, NULL, testParams.sampleRate ) != paFormatIsSupported )
+    {
+        printf( "Input not supported for this format!\n" );
+        return 0;
+    }
+    if( Pa_IsFormatSupported( NULL, &testParams.outputParameters, testParams.sampleRate ) != paFormatIsSupported )
+    {
+        printf( "Output not supported for this format!\n" );
+        return 0;
+    }
+
+    PaQa_SetupLoopbackContext( &loopbackContext, &testParams );
+
+    if( inputDevice == outputDevice )
+    {
+        // Use full duplex if checking for loopback on one device.
+        testParams.flags &= ~PAQA_FLAG_TWO_STREAMS;
+    }
+    else
+    {
+        // Use half duplex if checking for loopback on two different device.
+        testParams.flags = PAQA_FLAG_TWO_STREAMS;
+    }
+    err = PaQa_RunLoopback( &loopbackContext );
+    QA_ASSERT_TRUE("loopback detection callback did not run", (loopbackContext.callbackCount > 1) );
+
+    // Analyse recording to see if we captured the output.
+    // Start in the middle assuming past latency.
+    startFrame = testParams.maxFrames/2;
+    numFrames = testParams.maxFrames/2;
+    magLeft = PaQa_CorrelateSine( &loopbackContext.recordings[0],
+                                    loopbackContext.generators[0].frequency,
+                                    testParams.sampleRate,
+                                    startFrame, numFrames, NULL );
+    magRight = PaQa_CorrelateSine( &loopbackContext.recordings[1],
+                                    loopbackContext.generators[1].frequency,
+                                    testParams.sampleRate,
+                                    startFrame, numFrames, NULL );
+    printf("   Amplitudes: left = %f, right = %f\n", magLeft, magRight );
+
+    // Check for backwards cable.
+    loopbackIsConnected = ((magLeft > minAmplitude) && (magRight > minAmplitude));
+
+    if( !loopbackIsConnected )
+    {
+        double magLeftReverse = PaQa_CorrelateSine( &loopbackContext.recordings[0],
+                                                   loopbackContext.generators[1].frequency,
+                                                   testParams.sampleRate,
+                                                   startFrame, numFrames, NULL );
+
+        double magRightReverse = PaQa_CorrelateSine( &loopbackContext.recordings[1],
+                                                    loopbackContext.generators[0].frequency,
+                                                    testParams.sampleRate,
+                                                    startFrame, numFrames, NULL );
+
+        if ((magLeftReverse > minAmplitude) && (magRightReverse>minAmplitude))
+        {
+            printf("ERROR - You seem to have the left and right channels swapped on the loopback cable!\n");
+        }
+    }
+    else
+    {
+        double rms = 0.0;
+        if( PaQa_CheckForClippedLoopback( &loopbackContext ) )
+        {
+            // Clipped so don't use this loopback.
+            loopbackIsConnected = 0;
+        }
+
+        err = PaQa_MeasureBackgroundNoise( &loopbackContext, &rms );
+        printf("   Background noise = %f\n", rms );
+        if( err )
+        {
+            printf("ERROR - Could not measure background noise on this input!\n");
+            loopbackIsConnected = 0;
+        }
+        else if( rms > MAX_BACKGROUND_NOISE_RMS )
+        {
+            printf("ERROR - There is too much background noise on this input!\n");
+            loopbackIsConnected = 0;
+        }
+    }
+
+    PaQa_TeardownLoopbackContext( &loopbackContext );
+    return loopbackIsConnected;
+
+error:
+    PaQa_TeardownLoopbackContext( &loopbackContext );
+    return err;
+}
+
+/*******************************************************************/
+/**
+ * If there is a loopback connection then run the analysis.
+ */
+static int CheckLoopbackAndScan( UserOptions *userOptions,
+                                PaDeviceIndex iIn, PaDeviceIndex iOut )
+{
+    int loopbackConnected = PaQa_CheckForLoopBack( userOptions, iIn, iOut );
+    if( loopbackConnected > 0 )
+    {
+        PaQa_AnalyzeLoopbackConnection( userOptions, iIn, iOut );
+        return 1;
+    }
+    return 0;
+}
+
+/*******************************************************************/
+/**
+ * Scan every combination of output to input device.
+ * If a loopback is found the analyse the combination.
+ * The scan can be overridden using the -i and -o command line options.
+ */
+static int ScanForLoopback(UserOptions *userOptions)
+{
+    PaDeviceIndex iIn,iOut;
+    int  numLoopbacks = 0;
+    int  numDevices;
+    numDevices = Pa_GetDeviceCount();
+
+    // If both devices are specified then just use that combination.
+    if ((userOptions->inputDevice >= 0) && (userOptions->outputDevice >= 0))
+    {
+        numLoopbacks += CheckLoopbackAndScan( userOptions, userOptions->inputDevice, userOptions->outputDevice );
+    }
+    else if (userOptions->inputDevice >= 0)
+    {
+        // Just scan for output.
+        for( iOut=0; iOut<numDevices; iOut++ )
+        {
+            numLoopbacks += CheckLoopbackAndScan( userOptions, userOptions->inputDevice, iOut );
+        }
+    }
+    else if (userOptions->outputDevice >= 0)
+    {
+        // Just scan for input.
+        for( iIn=0; iIn<numDevices; iIn++ )
+        {
+            numLoopbacks += CheckLoopbackAndScan( userOptions, iIn, userOptions->outputDevice );
+        }
+    }
+    else
+    {
+        // Scan both.
+        for( iOut=0; iOut<numDevices; iOut++ )
+        {
+            for( iIn=0; iIn<numDevices; iIn++ )
+            {
+                numLoopbacks += CheckLoopbackAndScan( userOptions, iIn, iOut );
+            }
+        }
+    }
+    QA_ASSERT_TRUE( "No good loopback cable found.", (numLoopbacks > 0) );
+    return numLoopbacks;
+
+error:
+    return -1;
+}
+
+/*==========================================================================================*/
+int TestSampleFormatConversion( void )
+{
+    int i;
+    const float floatInput[] = { 1.0, 0.5, -0.5, -1.0 };
+
+    const char charInput[] = { 127, 64, -64, -128 };
+    const unsigned char ucharInput[] = { 255, 128+64, 64, 0 };
+    const short shortInput[] = { 32767, 32768/2, -32768/2, -32768 };
+    const int intInput[] = { 2147483647, 2147483647/2, -1073741824 /*-2147483648/2 doesn't work in msvc*/, -2147483648 };
+
+    float floatOutput[4];
+    short shortOutput[4];
+    int intOutput[4];
+    unsigned char ucharOutput[4];
+    char charOutput[4];
+
+    QA_ASSERT_EQUALS("int must be 32-bit", 4, (int) sizeof(int) );
+    QA_ASSERT_EQUALS("short must be 16-bit", 2, (int) sizeof(short) );
+
+    // from Float ======
+    PaQa_ConvertFromFloat( floatInput, 4, paUInt8, ucharOutput );
+    for( i=0; i<4; i++ )
+    {
+        QA_ASSERT_CLOSE_INT( "paFloat32 -> paUInt8 -> error", ucharInput[i], ucharOutput[i], 1 );
+    }
+
+    PaQa_ConvertFromFloat( floatInput, 4, paInt8, charOutput );
+    for( i=0; i<4; i++ )
+    {
+        QA_ASSERT_CLOSE_INT( "paFloat32 -> paInt8 -> error", charInput[i], charOutput[i], 1 );
+    }
+
+    PaQa_ConvertFromFloat( floatInput, 4, paInt16, shortOutput );
+    for( i=0; i<4; i++ )
+    {
+        QA_ASSERT_CLOSE_INT( "paFloat32 -> paInt16 error", shortInput[i], shortOutput[i], 1 );
+    }
+
+    PaQa_ConvertFromFloat( floatInput, 4, paInt32, intOutput );
+    for( i=0; i<4; i++ )
+    {
+        QA_ASSERT_CLOSE_INT( "paFloat32 -> paInt32 error", intInput[i], intOutput[i], 0x00010000 );
+    }
+
+
+    // to Float ======
+    memset( floatOutput, 0, sizeof(floatOutput) );
+    PaQa_ConvertToFloat( ucharInput, 4, paUInt8, floatOutput );
+    for( i=0; i<4; i++ )
+    {
+        QA_ASSERT_CLOSE( "paUInt8 -> paFloat32 error", floatInput[i], floatOutput[i], 0.01 );
+    }
+
+    memset( floatOutput, 0, sizeof(floatOutput) );
+    PaQa_ConvertToFloat( charInput, 4, paInt8, floatOutput );
+    for( i=0; i<4; i++ )
+    {
+        QA_ASSERT_CLOSE( "paInt8 -> paFloat32 error", floatInput[i], floatOutput[i], 0.01 );
+    }
+
+    memset( floatOutput, 0, sizeof(floatOutput) );
+    PaQa_ConvertToFloat( shortInput, 4, paInt16, floatOutput );
+    for( i=0; i<4; i++ )
+    {
+        QA_ASSERT_CLOSE( "paInt16 -> paFloat32 error", floatInput[i], floatOutput[i], 0.001 );
+    }
+
+    memset( floatOutput, 0, sizeof(floatOutput) );
+    PaQa_ConvertToFloat( intInput, 4, paInt32, floatOutput );
+    for( i=0; i<4; i++ )
+    {
+        QA_ASSERT_CLOSE( "paInt32 -> paFloat32 error", floatInput[i], floatOutput[i], 0.00001 );
+    }
+
+    return 0;
+
+error:
+    return -1;
+}
+
+
+/*******************************************************************/
+void usage( const char *name )
+{
+    printf("%s [-i# -o# -l# -r# -s# -m -w -dDir]\n", name);
+    printf("  -i# - Input device ID. Will scan for loopback cable if not specified.\n");
+    printf("  -o# - Output device ID. Will scan for loopback if not specified.\n");
+    printf("  -l# - Latency for both input and output in milliseconds.\n");
+    printf("  --inputLatency # Input latency in milliseconds.\n");
+    printf("  --outputLatency # Output latency in milliseconds.\n");
+    printf("  -r# - Sample Rate in Hz.  Will use multiple common rates if not specified.\n");
+    printf("  -s# - Size of callback buffer in frames, framesPerBuffer. Will use common values if not specified.\n");
+    printf("  -w  - Save bad recordings in a WAV file.\n");
+    printf("  -dDir - Path for Directory for WAV files. Default is current directory.\n");
+    printf("  -m  - Just test the DSP Math code and not the audio devices.\n");
+    printf("  -v  - Verbose reports.\n");
+}
+
+/*******************************************************************/
+int main( int argc, char **argv )
+{
+    int i;
+    UserOptions userOptions;
+    int result = 0;
+    int justMath = 0;
+    char *executableName = argv[0];
+
+    printf("PortAudio LoopBack Test built " __DATE__ " at " __TIME__ "\n");
+
+    if( argc > 1 ){
+        printf("running with arguments:");
+        for(i=1; i < argc; ++i )
+            printf(" %s", argv[i] );
+        printf("\n");
+    }else{
+        printf("running with no arguments\n");
+    }
+
+    memset(&userOptions, 0, sizeof(userOptions));
+    userOptions.inputDevice = paNoDevice;
+    userOptions.outputDevice = paNoDevice;
+    userOptions.sampleRate = -1;
+    userOptions.framesPerBuffer = -1;
+    userOptions.inputLatency = -1;
+    userOptions.outputLatency = -1;
+    userOptions.waveFilePath = ".";
+
+    // Process arguments. Skip name of executable.
+    i = 1;
+    while( i<argc )
+    {
+        char *arg = argv[i];
+        if( arg[0] == '-' )
+        {
+            switch(arg[1])
+            {
+                case 'i':
+                    userOptions.inputDevice = atoi(&arg[2]);
+                    break;
+                case 'o':
+                    userOptions.outputDevice = atoi(&arg[2]);
+                    break;
+                case 'l':
+                    userOptions.inputLatency = userOptions.outputLatency = atoi(&arg[2]);
+                    break;
+                case 'r':
+                    userOptions.sampleRate = atoi(&arg[2]);
+                    break;
+                case 's':
+                    userOptions.framesPerBuffer = atoi(&arg[2]);
+                    break;
+
+                case 'm':
+                    printf("Option -m set so just testing math and not the audio devices.\n");
+                    justMath = 1;
+                    break;
+
+                case 'w':
+                    userOptions.saveBadWaves = 1;
+                    break;
+                case 'd':
+                    userOptions.waveFilePath = &arg[2];
+                    break;
+
+                case 'v':
+                    userOptions.verbose = 1;
+                    break;
+
+                case 'h':
+                    usage( executableName );
+                    exit(0);
+                    break;
+
+                case '-':
+                {
+                    if( strcmp( &arg[2], "inputLatency" ) == 0 )
+                    {
+                        i += 1;
+                        userOptions.inputLatency = atoi(argv[i]);
+                    }
+                    else if( strcmp( &arg[2], "outputLatency" ) == 0 )
+                    {
+                        i += 1;
+                        userOptions.outputLatency = atoi(argv[i]);
+                    }
+                    else
+                    {
+                        printf("Illegal option: %s\n", arg);
+                        usage( executableName );
+                        exit(1);
+                    }
+
+                }
+                    break;
+
+
+                default:
+                    printf("Illegal option: %s\n", arg);
+                    usage( executableName );
+                    exit(1);
+                    break;
+            }
+        }
+        else
+        {
+            printf("Illegal argument: %s\n", arg);
+            usage( executableName );
+            exit(1);
+
+        }
+        i += 1;
+    }
+
+    result = PaQa_TestAnalyzer();
+
+    // Test sample format conversion tool.
+    result = TestSampleFormatConversion();
+
+    if( (result == 0) && (justMath == 0) )
+    {
+        Pa_Initialize();
+        printf( "PortAudio version number = %d\nPortAudio version text = '%s'\n",
+               Pa_GetVersion(), Pa_GetVersionText() );
+        printf( "=============== PortAudio Devices ========================\n" );
+        PaQa_ListAudioDevices();
+        if( Pa_GetDeviceCount() == 0 )
+            printf( "no devices found.\n" );
+
+        printf( "=============== Detect Loopback ==========================\n" );
+        ScanForLoopback(&userOptions);
+
+        Pa_Terminate();
+    }
+
+    if (g_testsFailed == 0)
+    {
+        printf("PortAudio QA SUCCEEDED! %d tests passed, %d tests failed\n", g_testsPassed, g_testsFailed );
+        return 0;
+
+    }
+    else
+    {
+        printf("PortAudio QA FAILED! %d tests passed, %d tests failed\n", g_testsPassed, g_testsFailed );
+        return 1;
+    }
+}