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Diffstat (limited to 'desiredata/src/s_audio_paring.c')
| -rw-r--r-- | desiredata/src/s_audio_paring.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/desiredata/src/s_audio_paring.c b/desiredata/src/s_audio_paring.c new file mode 100644 index 00000000..dcdcce0e --- /dev/null +++ b/desiredata/src/s_audio_paring.c @@ -0,0 +1,172 @@ +/* + * $Id: s_audio_paring.c,v 1.1.4.1.2.1.2.1 2007-07-31 00:10:37 matju Exp $ + * ringbuffer.c + * Ring Buffer 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. + */ +/* + * modified 2002/07/13 by olaf.matthes@gmx.de to allow any number if channels + */ + +#include <stdio.h> +#include <stdlib.h> +#include <math.h> +#include "s_audio_paring.h" +#include <string.h> + +/* Initialize FIFO. */ +long PD_RingBuffer_Init(RingBuffer *rbuf, long numBytes, void *dataPtr) { + rbuf->bufferSize = numBytes; + rbuf->buffer = (char *)dataPtr; + PD_RingBuffer_Flush( rbuf ); + return 0; +} +/*************************************************************************** +** Return number of bytes available for reading. */ +long PD_RingBuffer_GetReadAvailable(RingBuffer *rbuf) { + long ret = rbuf->writeIndex - rbuf->readIndex; + if (ret < 0) ret += 2 * rbuf->bufferSize; + if (ret < 0 || ret > rbuf->bufferSize) error("consistency check failed: PD_RingBuffer_GetReadAvailable"); + return ret; +} +/* Return number of bytes available for writing. */ +long PD_RingBuffer_GetWriteAvailable(RingBuffer *rbuf) { + return rbuf->bufferSize - PD_RingBuffer_GetReadAvailable(rbuf); +} + +/* Clear buffer. Should only be called when buffer is NOT being read. */ +void PD_RingBuffer_Flush(RingBuffer *rbuf) { + rbuf->writeIndex = rbuf->readIndex = 0; +} + +/* Get address of region(s) to which we can write data. If the region is contiguous, size2 will be zero. + If non-contiguous, size2 will be the size of second region. + Returns room available to be written or numBytes, whichever is smaller. */ +long PD_RingBuffer_GetWriteRegions(RingBuffer *rbuf, long numBytes, +void **dataPtr1, long *sizePtr1, void **dataPtr2, long *sizePtr2) { + long index; + long available = PD_RingBuffer_GetWriteAvailable(rbuf); + if (numBytes > available) numBytes = available; + /* Check to see if write is not contiguous. */ + index = rbuf->writeIndex; + while (index >= rbuf->bufferSize) index -= rbuf->bufferSize; + if ((index + numBytes) > rbuf->bufferSize) { + /* Write data in two blocks that wrap the buffer. */ + long firstHalf = rbuf->bufferSize - index; + *dataPtr1 = &rbuf->buffer[index]; + *sizePtr1 = firstHalf; + *dataPtr2 = &rbuf->buffer[0]; + *sizePtr2 = numBytes - firstHalf; + } else { + *dataPtr1 = &rbuf->buffer[index]; + *sizePtr1 = numBytes; + *dataPtr2 = NULL; + *sizePtr2 = 0; + } + return numBytes; +} + + +/*************************************************************************** +*/ +long PD_RingBuffer_AdvanceWriteIndex(RingBuffer *rbuf, long numBytes) { + long ret = rbuf->writeIndex + numBytes; + if (ret >= 2 * rbuf->bufferSize) ret -= 2 * rbuf->bufferSize; /* check for end of buffer */ + return rbuf->writeIndex = ret; +} + +/*************************************************************************** +** Get address of region(s) from which we can read data. +** If the region is contiguous, size2 will be zero. +** If non-contiguous, size2 will be the size of second region. +** Returns room available to be written or numBytes, whichever is smaller. +*/ +long PD_RingBuffer_GetReadRegions(RingBuffer *rbuf, long numBytes, +void **dataPtr1, long *sizePtr1, void **dataPtr2, long *sizePtr2) { + long index; + long available = PD_RingBuffer_GetReadAvailable(rbuf); + if (numBytes > available) numBytes = available; + /* Check to see if read is not contiguous. */ + index = rbuf->readIndex; + while (index >= rbuf->bufferSize) index -= rbuf->bufferSize; + if ((index + numBytes) > rbuf->bufferSize) { + /* Write data in two blocks that wrap the buffer. */ + long firstHalf = rbuf->bufferSize - index; + *dataPtr1 = &rbuf->buffer[index]; + *sizePtr1 = firstHalf; + *dataPtr2 = &rbuf->buffer[0]; + *sizePtr2 = numBytes - firstHalf; + } else { + *dataPtr1 = &rbuf->buffer[index]; + *sizePtr1 = numBytes; + *dataPtr2 = NULL; + *sizePtr2 = 0; + } + return numBytes; +} + +long PD_RingBuffer_AdvanceReadIndex( RingBuffer *rbuf, long numBytes ) { + long ret = (rbuf->readIndex + numBytes); + if( ret >= 2 * rbuf->bufferSize) ret -= 2 * rbuf->bufferSize; + return rbuf->readIndex = ret; +} + +/* Return bytes written. */ +long PD_RingBuffer_Write(RingBuffer *rbuf, const void *data, long numBytes) { + long size1, size2, numWritten; + void *data1, *data2; + numWritten = PD_RingBuffer_GetWriteRegions( rbuf, numBytes, &data1, &size1, &data2, &size2 ); + if (size2 > 0) { + memcpy(data1, data, size1); + data = ((char *)data) + size1; + memcpy(data2, data, size2); + } else { + memcpy(data1, data, size1); + } + PD_RingBuffer_AdvanceWriteIndex( rbuf, numWritten ); + return numWritten; +} + +/* Return bytes read. */ +long PD_RingBuffer_Read(RingBuffer *rbuf, void *data, long numBytes) { + long size1, size2, numRead; + void *data1, *data2; + numRead = PD_RingBuffer_GetReadRegions( rbuf, numBytes, &data1, &size1, &data2, &size2 ); + if (size2 > 0) { + memcpy(data, data1, size1); + data = ((char *)data) + size1; + memcpy(data, data2, size2); + } else { + memcpy(data, data1, size1); + } + PD_RingBuffer_AdvanceReadIndex( rbuf, numRead ); + return numRead; +} |