/*
 * $Id: pablio.c,v 1.1.1.1.4.4 2003/03/13 17:28:33 philburk Exp $
 * pablio.c
 * Portable Audio Blocking Input/Output utility.
 *
 * Author: Phil Burk, http://www.softsynth.com
 *
 * This program uses the PortAudio Portable Audio Library.
 * For more information see: http://www.audiomulch.com/portaudio/
 * Copyright (c) 1999-2000 Ross Bencina and 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.
 *
 * 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.
 *
 * 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.
 *
 */  
	
/* History:
 * PLB021214 - check for valid stream in CloseAudioStream() to prevent hang.
 *             add timeOutMSec to CloseAudioStream() to prevent hang.
 */ 
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "portaudio.h"
#include "ringbuffer.h"
#include "pablio.h"
#include <string.h>
	
/************************************************************************/ 
/******** Constants *****************************************************/ 
/************************************************************************/ 
	
#define FRAMES_PER_BUFFER    (256)
	
/************************************************************************/ 
/******** Prototypes ****************************************************/ 
/************************************************************************/ 

static int blockingIOCallback(void *inputBuffer, void *outputBuffer, 
unsigned long framesPerBuffer,
							   
PaTimestamp outTime, void *userData);

static PaError PABLIO_InitFIFO(RingBuffer * rbuf, long numFrames, long bytesPerFrame);

static PaError PABLIO_TermFIFO(RingBuffer * rbuf);


/************************************************************************/ 
/******** Functions *****************************************************/ 
/************************************************************************/ 
	
/* Called from PortAudio.
 * Read and write data only if there is room in FIFOs.
 */ 
static int blockingIOCallback(void *inputBuffer, void *outputBuffer, 
unsigned long framesPerBuffer,
							  
PaTimestamp outTime, void *userData) 
{
	
PABLIO_Stream * data = (PABLIO_Stream *) userData;
	
long numBytes = data->bytesPerFrame * framesPerBuffer;
	
(void) outTime;
	

		/* This may get called with NULL inputBuffer during initial setup. */ 
		if (inputBuffer != NULL)
		
 {
		
RingBuffer_Write(&data->inFIFO, inputBuffer, numBytes);
		
}
	
if (outputBuffer != NULL)
		
 {
		
int i;
		
int numRead = RingBuffer_Read(&data->outFIFO, outputBuffer, numBytes);
		
			/* Zero out remainder of buffer if we run out of data. */ 
			for (i = numRead; i < numBytes; i++)
			
 {
			
((char *) outputBuffer)[i] = 0;
		
} 
}
	

return 0;

}



/* Allocate buffer. */ 
static PaError PABLIO_InitFIFO(RingBuffer * rbuf, long numFrames, long bytesPerFrame) 
{
	
long numBytes = numFrames * bytesPerFrame;
	
char *buffer = (char *) malloc(numBytes);
	
if (buffer == NULL)
		return paInsufficientMemory;
	
memset(buffer, 0, numBytes);
	
return (PaError) RingBuffer_Init(rbuf, numBytes, buffer);

}



/* Free buffer. */ 
static PaError PABLIO_TermFIFO(RingBuffer * rbuf) 
{
	
if (rbuf->buffer)
		free(rbuf->buffer);
	
rbuf->buffer = NULL;
	
return paNoError;

}



/************************************************************
 * Write data to ring buffer.
 * Will not return until all the data has been written.
 */ 
long WriteAudioStream(PABLIO_Stream * aStream, void *data, long numFrames) 
{
	
long bytesWritten;
	
char *p = (char *) data;
	
long numBytes = aStream->bytesPerFrame * numFrames;
	
while (numBytes > 0)
		
 {
		
bytesWritten = RingBuffer_Write(&aStream->outFIFO, p, numBytes);
		
numBytes -= bytesWritten;
		
p += bytesWritten;
		
if (numBytes > 0)
			Pa_Sleep(10);
		
}
	
return numFrames;

}



/************************************************************
 * Read data from ring buffer.
 * Will not return until all the data has been read.
 */ 
long ReadAudioStream(PABLIO_Stream * aStream, void *data, long numFrames) 
{
	
long bytesRead;
	
char *p = (char *) data;
	
long numBytes = aStream->bytesPerFrame * numFrames;
	
while (numBytes > 0)
		
 {
		
bytesRead = RingBuffer_Read(&aStream->inFIFO, p, numBytes);
		
numBytes -= bytesRead;
		
p += bytesRead;
		
if (numBytes > 0)
			Pa_Sleep(10);
		
}
	
return numFrames;

}



/************************************************************
 * Return the number of frames that could be written to the stream without
 * having to wait.
 */ 
long GetAudioStreamWriteable(PABLIO_Stream * aStream) 
{
	
int bytesEmpty = RingBuffer_GetWriteAvailable(&aStream->outFIFO);
	
return bytesEmpty / aStream->bytesPerFrame;

}



/************************************************************
 * Return the number of frames that are available to be read from the
 * stream without having to wait.
 */ 
long GetAudioStreamReadable(PABLIO_Stream * aStream) 
{
	
int bytesFull = RingBuffer_GetReadAvailable(&aStream->inFIFO);
	
return bytesFull / aStream->bytesPerFrame;

}



/************************************************************/ 
static unsigned long RoundUpToNextPowerOf2(unsigned long n) 
{
	
long numBits = 0;
	
if (((n - 1) & n) == 0)
		return n;				/* Already Power of two. */
	
while (n > 0)
		
 {
		
n = n >> 1;
		
numBits++;
		
}
	
return (1 << numBits);

}



/************************************************************
 * Opens a PortAudio stream with default characteristics.
 * Allocates PABLIO_Stream structure.
 *
 * flags parameter can be an ORed combination of:
 *    PABLIO_READ, PABLIO_WRITE, or PABLIO_READ_WRITE,
 *    and either PABLIO_MONO or PABLIO_STEREO
 */ 
	PaError OpenAudioStream(PABLIO_Stream ** rwblPtr, double sampleRate, 
PaSampleFormat format, long flags, int indev,
							int outdev) 
{
	
long bytesPerSample;
	
long doRead = 0;
	
long doWrite = 0;
	
PaError err;
	
PABLIO_Stream * aStream;
	
long minNumBuffers;
	
long numFrames;
	

		/* Allocate PABLIO_Stream structure for caller. */ 
		aStream = (PABLIO_Stream *) malloc(sizeof(PABLIO_Stream));
	
if (aStream == NULL)
		return paInsufficientMemory;
	
memset(aStream, 0, sizeof(PABLIO_Stream));
	

		/* Determine size of a sample. */ 
		bytesPerSample = Pa_GetSampleSize(format);
	
if (bytesPerSample < 0)
		
 {
		
err = (PaError) bytesPerSample;
		
goto error;
		
}
	
aStream->samplesPerFrame = ((flags & PABLIO_MONO) != 0) ? 1 : 2;
	
aStream->bytesPerFrame = bytesPerSample * aStream->samplesPerFrame;
	

		/* Initialize PortAudio  */ 
		err = Pa_Initialize();
	
if (err != paNoError)
		goto error;
	

		/* Warning: numFrames must be larger than amount of data processed per interrupt
		 *    inside PA to prevent glitches. Just to be safe, adjust size upwards.
		 */ 
		minNumBuffers = 2 * Pa_GetMinNumBuffers(FRAMES_PER_BUFFER, sampleRate);
	
numFrames = minNumBuffers * FRAMES_PER_BUFFER;
	
		/* The PortAudio callback runs in a high priority thread. But PABLIO
		 * runs in a normal foreground thread. So we may have much worse
		 * latency in PABLIO. So adjust latency to a safe level.
		 */ 
	{
		
const int safeLatencyMSec = 200;
		
int minLatencyMSec = (int) ((1000 * numFrames) / sampleRate);
		
if (minLatencyMSec < safeLatencyMSec)
			
 {
			
numFrames = (int) ((safeLatencyMSec * sampleRate) / 1000);
			
}
	
} 
numFrames = RoundUpToNextPowerOf2(numFrames);
	

		/* Initialize Ring Buffers */ 
		doRead = ((flags & PABLIO_READ) != 0);
	
doWrite = ((flags & PABLIO_WRITE) != 0);
	
if (doRead)
		
 {
		
err = PABLIO_InitFIFO(&aStream->inFIFO, numFrames, aStream->bytesPerFrame);
		
if (err != paNoError)
			goto error;
		
}
	
if (doWrite)
		
 {
		
long numBytes;
		
err = PABLIO_InitFIFO(&aStream->outFIFO, numFrames, aStream->bytesPerFrame);
		
if (err != paNoError)
			goto error;
		
			/* Make Write FIFO appear full initially. */ 
			numBytes = RingBuffer_GetWriteAvailable(&aStream->outFIFO);
		
RingBuffer_AdvanceWriteIndex(&aStream->outFIFO, numBytes);
		
}
	

		/* Open a PortAudio stream that we will use to communicate with the underlying
		 * audio drivers. */ 
		err = Pa_OpenStream(
&aStream->stream, 
							(doRead ? (indev > -1) ? indev : Pa_GetDefaultInputDeviceID() : paNoDevice), 
							(doRead ? aStream->samplesPerFrame : 0), 
format, 
NULL, 
							(doWrite ? (outdev > -1) ? outdev : Pa_GetDefaultOutputDeviceID() : paNoDevice), 
							(doWrite ? aStream->samplesPerFrame : 0), 
format, 
NULL, 
sampleRate, 
FRAMES_PER_BUFFER,
							
minNumBuffers, 
paClipOff,
							/* we won't output out of range samples so don't bother clipping them */ 
							blockingIOCallback, 
aStream);
	
if (err != paNoError)
		goto error;
	

err = Pa_StartStream(aStream->stream);
	
if (err != paNoError)
		goto error;
	

*rwblPtr = aStream;
	
return paNoError;
  

error:
CloseAudioStream(aStream);
	
*rwblPtr = NULL;
	
return err;

}



/************************************************************/ 
	PaError CloseAudioStream(PABLIO_Stream * aStream) 
{
	
PaError err = paNoError;
	
int bytesEmpty;
	
int byteSize = aStream->outFIFO.bufferSize;
	

if (aStream->stream != NULL)	/* Make sure stream was opened. PLB021214 */
		
 {
		
			/* If we are writing data, make sure we play everything written. */ 
			if (byteSize > 0)
			
 {
			
int timeOutMSec = 2000;
			
bytesEmpty = RingBuffer_GetWriteAvailable(&aStream->outFIFO);
			
while ((bytesEmpty < byteSize) && (timeOutMSec > 0))
				
 {
				
Pa_Sleep(20);
				
timeOutMSec -= 20;
				
bytesEmpty = RingBuffer_GetWriteAvailable(&aStream->outFIFO);
				
}
			
}
		
err = Pa_StopStream(aStream->stream);
		
if (err != paNoError)
			goto error;
		
err = Pa_CloseStream(aStream->stream);
		
}
  

error:
Pa_Terminate();
	
PABLIO_TermFIFO(&aStream->inFIFO);
	
PABLIO_TermFIFO(&aStream->outFIFO);
	
free(aStream);
	
return err;

}


