From 2000464c73ed4419ce1f49ddc67e89a8f22d5204 Mon Sep 17 00:00:00 2001
From: jpbl <jpbl>
Date: Thu, 9 Jun 2005 18:20:52 +0000
Subject: [PATCH] cleanup
---
src/audio/pa_converters.h | 254 ++++++++++++++++++++++++++++++++++++++
src/audio/pa_dither.h | 91 ++++++++++++++
2 files changed, 345 insertions(+)
create mode 100644 src/audio/pa_converters.h
create mode 100644 src/audio/pa_dither.h
diff --git a/src/audio/pa_converters.h b/src/audio/pa_converters.h
new file mode 100644
index 0000000000..1d83c990bb
--- /dev/null
+++ b/src/audio/pa_converters.h
@@ -0,0 +1,254 @@
+#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.
+ *
+ * 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.
+ */
+
+/** @file
+ @brief Conversion functions used to convert buffers of samples from one
+ format to another.
+*/
+
+
+#include "portaudio.h" /* for PaSampleFormat */
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif /* __cplusplus */
+
+
+struct PaUtilTriangularDitherGenerator;
+
+
+/** Choose an available sample format which is most appropriate for
+ representing the requested format. If the requested format is not available
+ higher quality formats are considered before lower quality formates.
+ @param availableFormats A variable containing the logical OR of all available
+ formats.
+ @param format The desired format.
+ @return The most appropriate available format for representing the requested
+ format.
+*/
+PaSampleFormat PaUtil_SelectClosestAvailableFormat(
+ PaSampleFormat availableFormats, PaSampleFormat format );
+
+
+/* high level conversions functions for use by implementations */
+
+
+/** The generic sample converter prototype. Sample converters convert count
+ samples from sourceBuffer to destinationBuffer. The actual type of the data
+ pointed to by these parameters varys for different converter functions.
+ @param destinationBuffer A pointer to the first sample of the destination.
+ @param destinationStride An offset between successive destination samples
+ expressed in samples (not bytes.) It may be negative.
+ @param sourceBuffer A pointer to the first sample of the source.
+ @param sourceStride An offset between successive source samples
+ expressed in samples (not bytes.) It may be negative.
+ @param count The number of samples to convert.
+ @param ditherState State information used to calculate dither. Converters
+ that do not perform dithering will ignore this parameter, in which case
+ NULL or invalid dither state may be passed.
+*/
+typedef void PaUtilConverter(
+ void *destinationBuffer, signed int destinationStride,
+ void *sourceBuffer, signed int sourceStride,
+ unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator );
+
+
+/** Find a sample converter function for the given source and destinations
+ formats and flags (clip and dither.)
+ @return
+ A pointer to a PaUtilConverter which will perform the requested
+ conversion, or NULL if the given format conversion is not supported.
+ For conversions where clipping or dithering is not necessary, the
+ clip and dither flags are ignored and a non-clipping or dithering
+ version is returned.
+ If the source and destination formats are the same, a function which
+ copies data of the appropriate size will be returned.
+*/
+PaUtilConverter* PaUtil_SelectConverter( PaSampleFormat sourceFormat,
+ PaSampleFormat destinationFormat, PaStreamFlags flags );
+
+
+/** The generic buffer zeroer prototype. Buffer zeroers copy count zeros to
+ destinationBuffer. The actual type of the data pointed to varys for
+ different zeroer functions.
+ @param destinationBuffer A pointer to the first sample of the destination.
+ @param destinationStride An offset between successive destination samples
+ expressed in samples (not bytes.) It may be negative.
+ @param count The number of samples to zero.
+*/
+typedef void PaUtilZeroer(
+ void *destinationBuffer, signed int destinationStride, unsigned int count );
+
+
+/** Find a buffer zeroer function for the given destination format.
+ @return
+ A pointer to a PaUtilZeroer which will perform the requested
+ zeroing.
+*/
+PaUtilZeroer* PaUtil_SelectZeroer( PaSampleFormat destinationFormat );
+
+/*----------------------------------------------------------------------------*/
+/* low level functions and data structures which may be used for
+ substituting conversion functions */
+
+
+/** The type used to store all sample conversion functions.
+ @see paConverters;
+*/
+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;
+
+
+/** A table of pointers to all required converter functions.
+ PaUtil_SelectConverter() uses this table to lookup the appropriate
+ conversion functions. The fields of this structure are initialized
+ with default conversion functions. Fields may be NULL, indicating that
+ no conversion function is available. User code may substitue optimised
+ conversion functions by assigning different function pointers to
+ these fields.
+
+ @note
+ If the PA_NO_STANDARD_CONVERTERS preprocessor variable is defined,
+ PortAudio's standard converters will not be compiled, and all fields
+ of this structure will be initialized to NULL. In such cases, users
+ should supply their own conversion functions if the require PortAudio
+ to open a stream that requires sample conversion.
+
+ @see PaUtilConverterTable, PaUtilConverter, PaUtil_SelectConverter
+*/
+extern PaUtilConverterTable paConverters;
+
+
+/** The type used to store all buffer zeroing functions.
+ @see paZeroers;
+*/
+typedef struct{
+ PaUtilZeroer *ZeroU8; /* unsigned 8 bit, zero == 128 */
+ PaUtilZeroer *Zero8;
+ PaUtilZeroer *Zero16;
+ PaUtilZeroer *Zero24;
+ PaUtilZeroer *Zero32;
+} PaUtilZeroerTable;
+
+
+/** A table of pointers to all required zeroer functions.
+ PaUtil_SelectZeroer() uses this table to lookup the appropriate
+ conversion functions. The fields of this structure are initialized
+ with default conversion functions. User code may substitue optimised
+ conversion functions by assigning different function pointers to
+ these fields.
+
+ @note
+ If the PA_NO_STANDARD_ZEROERS preprocessor variable is defined,
+ PortAudio's standard zeroers will not be compiled, and all fields
+ of this structure will be initialized to NULL. In such cases, users
+ should supply their own zeroing functions for the sample sizes which
+ they intend to use.
+
+ @see PaUtilZeroerTable, PaUtilZeroer, PaUtil_SelectZeroer
+*/
+extern PaUtilZeroerTable paZeroers;
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+#endif /* PA_CONVERTERS_H */
diff --git a/src/audio/pa_dither.h b/src/audio/pa_dither.h
new file mode 100644
index 0000000000..148db275fb
--- /dev/null
+++ b/src/audio/pa_dither.h
@@ -0,0 +1,91 @@
+#ifndef PA_DITHER_H
+#define PA_DITHER_H
+/*
+ * $Id$
+ * Portable Audio I/O Library triangular dither generator
+ *
+ * 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.
+ *
+ * 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.
+ */
+
+/** @file
+ @brief Functions for generating dither noise
+*/
+
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif /* __cplusplus */
+
+
+/** @brief State needed to generate a dither signal */
+typedef struct PaUtilTriangularDitherGenerator{
+ unsigned long previous;
+ unsigned long randSeed1;
+ unsigned long randSeed2;
+} PaUtilTriangularDitherGenerator;
+
+
+/** @brief Initialize dither state */
+void PaUtil_InitializeTriangularDitherState( PaUtilTriangularDitherGenerator *ditherState );
+
+
+/**
+ @brief Calculate 2 LSB dither signal with a triangular distribution.
+ Ranged for adding to a 1 bit right-shifted 32 bit integer
+ prior to >>15. eg:
+<pre>
+ signed long in = *
+ signed long dither = PaUtil_Generate16BitTriangularDither( ditherState );
+ signed short out = (signed short)(((in>>1) + dither) >> 15);
+</pre>
+ @return
+ A signed long with a range of +32767 to -32768
+*/
+signed long PaUtil_Generate16BitTriangularDither( PaUtilTriangularDitherGenerator *ditherState );
+
+
+/**
+ @brief Calculate 2 LSB dither signal with a triangular distribution.
+ Ranged for adding to a pre-scaled float.
+<pre>
+ float in = *
+ float dither = PaUtil_GenerateFloatTriangularDither( ditherState );
+ // use smaller scaler to prevent overflow when we add the dither
+ signed short out = (signed short)(in*(32766.0f) + dither );
+</pre>
+ @return
+ A float with a range of -2.0 to +1.99999.
+*/
+float PaUtil_GenerateFloatTriangularDither( PaUtilTriangularDitherGenerator *ditherState );
+
+
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+#endif /* PA_DITHER_H */
--
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