pa_converters.h

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#ifndef PA_CONVERTERS_H
#define PA_CONVERTERS_H
/*
 * $Id$
 * Portable Audio I/O Library sample conversion mechanism
 *
 * Based on the Open Source API proposed by Ross Bencina
 * Copyright (c) 1999-2002 Phil Burk, 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 "portaudio.h"  /* for PaSampleFormat */

#ifdef __cplusplus
extern "C"
{
#endif /* __cplusplus */


struct PaUtilTriangularDitherGenerator;


PaSampleFormat PaUtil_SelectClosestAvailableFormat(
        PaSampleFormat availableFormats, PaSampleFormat format );


/* high level conversions functions for use by implementations */


typedef void PaUtilConverter(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator );


PaUtilConverter* PaUtil_SelectConverter( PaSampleFormat sourceFormat,
        PaSampleFormat destinationFormat, PaStreamFlags flags );


typedef void PaUtilZeroer(
    void *destinationBuffer, signed int destinationStride, unsigned int count );

    
PaUtilZeroer* PaUtil_SelectZeroer( PaSampleFormat destinationFormat );

/*----------------------------------------------------------------------------*/
/* low level functions and data structures which may be used for
    substituting conversion functions */


typedef struct{
    PaUtilConverter *Float32_To_Int32;
    PaUtilConverter *Float32_To_Int32_Dither;
    PaUtilConverter *Float32_To_Int32_Clip;
    PaUtilConverter *Float32_To_Int32_DitherClip;

    PaUtilConverter *Float32_To_Int24;
    PaUtilConverter *Float32_To_Int24_Dither;
    PaUtilConverter *Float32_To_Int24_Clip;
    PaUtilConverter *Float32_To_Int24_DitherClip;
    
    PaUtilConverter *Float32_To_Int16;
    PaUtilConverter *Float32_To_Int16_Dither;
    PaUtilConverter *Float32_To_Int16_Clip;
    PaUtilConverter *Float32_To_Int16_DitherClip;

    PaUtilConverter *Float32_To_Int8;
    PaUtilConverter *Float32_To_Int8_Dither;
    PaUtilConverter *Float32_To_Int8_Clip;
    PaUtilConverter *Float32_To_Int8_DitherClip;

    PaUtilConverter *Float32_To_UInt8;
    PaUtilConverter *Float32_To_UInt8_Dither;
    PaUtilConverter *Float32_To_UInt8_Clip;
    PaUtilConverter *Float32_To_UInt8_DitherClip;

    PaUtilConverter *Int32_To_Float32;
    PaUtilConverter *Int32_To_Int24;
    PaUtilConverter *Int32_To_Int24_Dither;
    PaUtilConverter *Int32_To_Int16;
    PaUtilConverter *Int32_To_Int16_Dither;
    PaUtilConverter *Int32_To_Int8;
    PaUtilConverter *Int32_To_Int8_Dither;
    PaUtilConverter *Int32_To_UInt8;
    PaUtilConverter *Int32_To_UInt8_Dither;

    PaUtilConverter *Int24_To_Float32;
    PaUtilConverter *Int24_To_Int32;
    PaUtilConverter *Int24_To_Int16;
    PaUtilConverter *Int24_To_Int16_Dither;
    PaUtilConverter *Int24_To_Int8;
    PaUtilConverter *Int24_To_Int8_Dither;
    PaUtilConverter *Int24_To_UInt8;
    PaUtilConverter *Int24_To_UInt8_Dither;

    PaUtilConverter *Int16_To_Float32;
    PaUtilConverter *Int16_To_Int32;
    PaUtilConverter *Int16_To_Int24;
    PaUtilConverter *Int16_To_Int8;
    PaUtilConverter *Int16_To_Int8_Dither;
    PaUtilConverter *Int16_To_UInt8;
    PaUtilConverter *Int16_To_UInt8_Dither;

    PaUtilConverter *Int8_To_Float32;
    PaUtilConverter *Int8_To_Int32;
    PaUtilConverter *Int8_To_Int24;
    PaUtilConverter *Int8_To_Int16;
    PaUtilConverter *Int8_To_UInt8;
    
    PaUtilConverter *UInt8_To_Float32;
    PaUtilConverter *UInt8_To_Int32;
    PaUtilConverter *UInt8_To_Int24;
    PaUtilConverter *UInt8_To_Int16;
    PaUtilConverter *UInt8_To_Int8;

    PaUtilConverter *Copy_8_To_8;       /* copy without any conversion */
    PaUtilConverter *Copy_16_To_16;     /* copy without any conversion */
    PaUtilConverter *Copy_24_To_24;     /* copy without any conversion */
    PaUtilConverter *Copy_32_To_32;     /* copy without any conversion */
} PaUtilConverterTable;


extern PaUtilConverterTable paConverters;


typedef struct{
    PaUtilZeroer *ZeroU8; /* unsigned 8 bit, zero == 128 */
    PaUtilZeroer *Zero8;
    PaUtilZeroer *Zero16;
    PaUtilZeroer *Zero24;
    PaUtilZeroer *Zero32;
} PaUtilZeroerTable;


extern PaUtilZeroerTable paZeroers;

#ifdef __cplusplus
}
#endif /* __cplusplus */
#endif /* PA_CONVERTERS_H */