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authorsanine <sanine.not@pm.me>2022-08-27 23:52:56 -0500
committersanine <sanine.not@pm.me>2022-08-27 23:52:56 -0500
commita4dd0ad63c00f4dee3b86dfd3075d1d61b2b3180 (patch)
tree13bd5bfa15e6fea2a12f176bae79adf9c6fd0933 /3rdparty/portaudio/src/common/pa_process.h
parentbde3e4f1bb7b8f8abca0884a7d994ee1c17a66b1 (diff)
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+#ifndef PA_PROCESS_H
+#define PA_PROCESS_H
+/*
+ * $Id$
+ * Portable Audio I/O Library callback buffer processing adapters
+ *
+ * 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.
+ */
+
+/** @file
+ @ingroup common_src
+
+ @brief Buffer Processor prototypes. A Buffer Processor performs buffer length
+ adaption, coordinates sample format conversion, and interleaves/deinterleaves
+ channels.
+
+ <h3>Overview</h3>
+
+ The "Buffer Processor" (PaUtilBufferProcessor) manages conversion of audio
+ data from host buffers to user buffers and back again. Where required, the
+ buffer processor takes care of converting between host and user sample formats,
+ interleaving and deinterleaving multichannel buffers, and adapting between host
+ and user buffers with different lengths. The buffer processor may be used with
+ full and half duplex streams, for both callback streams and blocking read/write
+ streams.
+
+ One of the important capabilities provided by the buffer processor is
+ the ability to adapt between user and host buffer sizes of different lengths
+ with minimum latency. Although this task is relatively easy to perform when
+ the host buffer size is an integer multiple of the user buffer size, the
+ problem is more complicated when this is not the case - especially for
+ full-duplex callback streams. Where necessary the adaption is implemented by
+ internally buffering some input and/or output data. The buffer adation
+ algorithm used by the buffer processor was originally implemented by
+ Stephan Letz for the ASIO version of PortAudio, and is described in his
+ Callback_adaption_.pdf which is included in the distribution.
+
+ The buffer processor performs sample conversion using the functions provided
+ by pa_converters.c.
+
+ The following sections provide an overview of how to use the buffer processor.
+ Interested readers are advised to consult the host API implementations for
+ examples of buffer processor usage.
+
+
+ <h4>Initialization, resetting and termination</h4>
+
+ When a stream is opened, the buffer processor should be initialized using
+ PaUtil_InitializeBufferProcessor. This function initializes internal state
+ and allocates temporary buffers as necessary according to the supplied
+ configuration parameters. Some of the parameters correspond to those requested
+ by the user in their call to Pa_OpenStream(), others reflect the requirements
+ of the host API implementation - they indicate host buffer sizes, formats,
+ and the type of buffering which the Host API uses. The buffer processor should
+ be initialized for callback streams and blocking read/write streams.
+
+ Call PaUtil_ResetBufferProcessor to clear any sample data which is present
+ in the buffer processor before starting to use it (for example when
+ Pa_StartStream is called).
+
+ When the buffer processor is no longer used call
+ PaUtil_TerminateBufferProcessor.
+
+
+ <h4>Using the buffer processor for a callback stream</h4>
+
+ The buffer processor's role in a callback stream is to take host input buffers
+ process them with the stream callback, and fill host output buffers. For a
+ full duplex stream, the buffer processor handles input and output simultaneously
+ due to the requirements of the minimum-latency buffer adation algorithm.
+
+ When a host buffer becomes available, the implementation should call
+ the buffer processor to process the buffer. The buffer processor calls the
+ stream callback to consume and/or produce audio data as necessary. The buffer
+ processor will convert sample formats, interleave/deinterleave channels,
+ and slice or chunk the data to the appropriate buffer lengths according to
+ the requirements of the stream callback and the host API.
+
+ To process a host buffer (or a pair of host buffers for a full-duplex stream)
+ use the following calling sequence:
+
+ -# Call PaUtil_BeginBufferProcessing
+ -# For a stream which takes input:
+ - Call PaUtil_SetInputFrameCount with the number of frames in the host input
+ buffer.
+ - Call one of the following functions one or more times to tell the
+ buffer processor about the host input buffer(s): PaUtil_SetInputChannel,
+ PaUtil_SetInterleavedInputChannels, PaUtil_SetNonInterleavedInputChannel.
+ Which function you call will depend on whether the host buffer(s) are
+ interleaved or not.
+ - If the available host data is split across two buffers (for example a
+ data range at the end of a circular buffer and another range at the
+ beginning of the circular buffer), also call
+ PaUtil_Set2ndInputFrameCount, PaUtil_Set2ndInputChannel,
+ PaUtil_Set2ndInterleavedInputChannels,
+ PaUtil_Set2ndNonInterleavedInputChannel as necessary to tell the buffer
+ processor about the second buffer.
+ -# For a stream which generates output:
+ - Call PaUtil_SetOutputFrameCount with the number of frames in the host
+ output buffer.
+ - Call one of the following functions one or more times to tell the
+ buffer processor about the host output buffer(s): PaUtil_SetOutputChannel,
+ PaUtil_SetInterleavedOutputChannels, PaUtil_SetNonInterleavedOutputChannel.
+ Which function you call will depend on whether the host buffer(s) are
+ interleaved or not.
+ - If the available host output buffer space is split across two buffers
+ (for example a data range at the end of a circular buffer and another
+ range at the beginning of the circular buffer), call
+ PaUtil_Set2ndOutputFrameCount, PaUtil_Set2ndOutputChannel,
+ PaUtil_Set2ndInterleavedOutputChannels,
+ PaUtil_Set2ndNonInterleavedOutputChannel as necessary to tell the buffer
+ processor about the second buffer.
+ -# Call PaUtil_EndBufferProcessing, this function performs the actual data
+ conversion and processing.
+
+
+ <h4>Using the buffer processor for a blocking read/write stream</h4>
+
+ Blocking read/write streams use the buffer processor to convert and copy user
+ output data to a host buffer, and to convert and copy host input data to
+ the user's buffer. The buffer processor does not perform any buffer adaption.
+ When using the buffer processor in a blocking read/write stream the input and
+ output conversion are performed separately by the PaUtil_CopyInput and
+ PaUtil_CopyOutput functions.
+
+ To copy data from a host input buffer to the buffer(s) which the user supplies
+ to Pa_ReadStream, use the following calling sequence.
+
+ - Repeat the following three steps until the user buffer(s) have been filled
+ with samples from the host input buffers:
+ -# Call PaUtil_SetInputFrameCount with the number of frames in the host
+ input buffer.
+ -# Call one of the following functions one or more times to tell the
+ buffer processor about the host input buffer(s): PaUtil_SetInputChannel,
+ PaUtil_SetInterleavedInputChannels, PaUtil_SetNonInterleavedInputChannel.
+ Which function you call will depend on whether the host buffer(s) are
+ interleaved or not.
+ -# Call PaUtil_CopyInput with the user buffer pointer (or a copy of the
+ array of buffer pointers for a non-interleaved stream) passed to
+ Pa_ReadStream, along with the number of frames in the user buffer(s).
+ Be careful to pass a <i>copy</i> of the user buffer pointers to
+ PaUtil_CopyInput because PaUtil_CopyInput advances the pointers to
+ the start of the next region to copy.
+ - PaUtil_CopyInput will not copy more data than is available in the
+ host buffer(s), so the above steps need to be repeated until the user
+ buffer(s) are full.
+
+
+ To copy data to the host output buffer from the user buffers(s) supplied
+ to Pa_WriteStream use the following calling sequence.
+
+ - Repeat the following three steps until all frames from the user buffer(s)
+ have been copied to the host API:
+ -# Call PaUtil_SetOutputFrameCount with the number of frames in the host
+ output buffer.
+ -# Call one of the following functions one or more times to tell the
+ buffer processor about the host output buffer(s): PaUtil_SetOutputChannel,
+ PaUtil_SetInterleavedOutputChannels, PaUtil_SetNonInterleavedOutputChannel.
+ Which function you call will depend on whether the host buffer(s) are
+ interleaved or not.
+ -# Call PaUtil_CopyOutput with the user buffer pointer (or a copy of the
+ array of buffer pointers for a non-interleaved stream) passed to
+ Pa_WriteStream, along with the number of frames in the user buffer(s).
+ Be careful to pass a <i>copy</i> of the user buffer pointers to
+ PaUtil_CopyOutput because PaUtil_CopyOutput advances the pointers to
+ the start of the next region to copy.
+ - PaUtil_CopyOutput will not copy more data than fits in the host buffer(s),
+ so the above steps need to be repeated until all user data is copied.
+*/
+
+
+#include "portaudio.h"
+#include "pa_converters.h"
+#include "pa_dither.h"
+
+#ifdef __cplusplus
+extern "C"
+{
+#endif /* __cplusplus */
+
+
+/** @brief Mode flag passed to PaUtil_InitializeBufferProcessor indicating the type
+ of buffering that the host API uses.
+
+ The mode used depends on whether the host API or the implementation manages
+ the buffers, and how these buffers are used (scatter gather, circular buffer).
+*/
+typedef enum {
+/** The host buffer size is a fixed known size. */
+ paUtilFixedHostBufferSize,
+
+/** The host buffer size may vary, but has a known maximum size. */
+ paUtilBoundedHostBufferSize,
+
+/** Nothing is known about the host buffer size. */
+ paUtilUnknownHostBufferSize,
+
+/** The host buffer size varies, and the client does not require the buffer
+ processor to consume all of the input and fill all of the output buffer. This
+ is useful when the implementation has access to the host API's circular buffer
+ and only needs to consume/fill some of it, not necessarily all of it, with each
+ call to the buffer processor. This is the only mode where
+ PaUtil_EndBufferProcessing() may not consume the whole buffer.
+*/
+ paUtilVariableHostBufferSizePartialUsageAllowed
+}PaUtilHostBufferSizeMode;
+
+
+/** @brief An auxiliary data structure used internally by the buffer processor
+ to represent host input and output buffers. */
+typedef struct PaUtilChannelDescriptor{
+ void *data;
+ unsigned int stride; /**< stride in samples, not bytes */
+}PaUtilChannelDescriptor;
+
+
+/** @brief The main buffer processor data structure.
+
+ Allocate one of these, initialize it with PaUtil_InitializeBufferProcessor
+ and terminate it with PaUtil_TerminateBufferProcessor.
+*/
+typedef struct {
+ unsigned long framesPerUserBuffer;
+ unsigned long framesPerHostBuffer;
+
+ PaUtilHostBufferSizeMode hostBufferSizeMode;
+ int useNonAdaptingProcess;
+ int userOutputSampleFormatIsEqualToHost;
+ int userInputSampleFormatIsEqualToHost;
+ unsigned long framesPerTempBuffer;
+
+ unsigned int inputChannelCount;
+ unsigned int bytesPerHostInputSample;
+ unsigned int bytesPerUserInputSample;
+ int userInputIsInterleaved;
+ PaUtilConverter *inputConverter;
+ PaUtilZeroer *inputZeroer;
+
+ unsigned int outputChannelCount;
+ unsigned int bytesPerHostOutputSample;
+ unsigned int bytesPerUserOutputSample;
+ int userOutputIsInterleaved;
+ PaUtilConverter *outputConverter;
+ PaUtilZeroer *outputZeroer;
+
+ unsigned long initialFramesInTempInputBuffer;
+ unsigned long initialFramesInTempOutputBuffer;
+
+ void *tempInputBuffer; /**< used for slips, block adaption, and conversion. */
+ void **tempInputBufferPtrs; /**< storage for non-interleaved buffer pointers, NULL for interleaved user input */
+ unsigned long framesInTempInputBuffer; /**< frames remaining in input buffer from previous adaption iteration */
+
+ void *tempOutputBuffer; /**< used for slips, block adaption, and conversion. */
+ void **tempOutputBufferPtrs; /**< storage for non-interleaved buffer pointers, NULL for interleaved user output */
+ unsigned long framesInTempOutputBuffer; /**< frames remaining in input buffer from previous adaption iteration */
+
+ PaStreamCallbackTimeInfo *timeInfo;
+
+ PaStreamCallbackFlags callbackStatusFlags;
+
+ int hostInputIsInterleaved;
+ unsigned long hostInputFrameCount[2];
+ PaUtilChannelDescriptor *hostInputChannels[2]; /**< pointers to arrays of channel descriptors.
+ pointers are NULL for half-duplex output processing.
+ hostInputChannels[i].data is NULL when the caller
+ calls PaUtil_SetNoInput()
+ */
+ int hostOutputIsInterleaved;
+ unsigned long hostOutputFrameCount[2];
+ PaUtilChannelDescriptor *hostOutputChannels[2]; /**< pointers to arrays of channel descriptors.
+ pointers are NULL for half-duplex input processing.
+ hostOutputChannels[i].data is NULL when the caller
+ calls PaUtil_SetNoOutput()
+ */
+
+ PaUtilTriangularDitherGenerator ditherGenerator;
+
+ double samplePeriod;
+
+ PaStreamCallback *streamCallback;
+ void *userData;
+} PaUtilBufferProcessor;
+
+
+/** @name Initialization, termination, resetting and info */
+/*@{*/
+
+/** Initialize a buffer processor's representation stored in a
+ PaUtilBufferProcessor structure. Be sure to call
+ PaUtil_TerminateBufferProcessor after finishing with a buffer processor.
+
+ @param bufferProcessor The buffer processor structure to initialize.
+
+ @param inputChannelCount The number of input channels as passed to
+ Pa_OpenStream or 0 for an output-only stream.
+
+ @param userInputSampleFormat Format of user input samples, as passed to
+ Pa_OpenStream. This parameter is ignored for ouput-only streams.
+
+ @param hostInputSampleFormat Format of host input samples. This parameter is
+ ignored for output-only streams. See note about host buffer interleave below.
+
+ @param outputChannelCount The number of output channels as passed to
+ Pa_OpenStream or 0 for an input-only stream.
+
+ @param userOutputSampleFormat Format of user output samples, as passed to
+ Pa_OpenStream. This parameter is ignored for input-only streams.
+
+ @param hostOutputSampleFormat Format of host output samples. This parameter is
+ ignored for input-only streams. See note about host buffer interleave below.
+
+ @param sampleRate Sample rate of the stream. The more accurate this is the
+ better - it is used for updating time stamps when adapting buffers.
+
+ @param streamFlags Stream flags as passed to Pa_OpenStream, this parameter is
+ used for selecting special sample conversion options such as clipping and
+ dithering.
+
+ @param framesPerUserBuffer Number of frames per user buffer, as requested
+ by the framesPerBuffer parameter to Pa_OpenStream. This parameter may be
+ zero to indicate that the user will accept any (and varying) buffer sizes.
+
+ @param framesPerHostBuffer Specifies the number of frames per host buffer
+ for the fixed buffer size mode, and the maximum number of frames
+ per host buffer for the bounded host buffer size mode. It is ignored for
+ the other modes.
+
+ @param hostBufferSizeMode A mode flag indicating the size variability of
+ host buffers that will be passed to the buffer processor. See
+ PaUtilHostBufferSizeMode for further details.
+
+ @param streamCallback The user stream callback passed to Pa_OpenStream.
+
+ @param userData The user data field passed to Pa_OpenStream.
+
+ @note The interleave flag is ignored for host buffer formats. Host
+ interleave is determined by the use of different SetInput and SetOutput
+ functions.
+
+ @return An error code indicating whether the initialization was successful.
+ If the error code is not PaNoError, the buffer processor was not initialized
+ and should not be used.
+
+ @see Pa_OpenStream, PaUtilHostBufferSizeMode, PaUtil_TerminateBufferProcessor
+*/
+PaError PaUtil_InitializeBufferProcessor( PaUtilBufferProcessor* bufferProcessor,
+ int inputChannelCount, PaSampleFormat userInputSampleFormat,
+ PaSampleFormat hostInputSampleFormat,
+ int outputChannelCount, PaSampleFormat userOutputSampleFormat,
+ PaSampleFormat hostOutputSampleFormat,
+ double sampleRate,
+ PaStreamFlags streamFlags,
+ unsigned long framesPerUserBuffer, /* 0 indicates don't care */
+ unsigned long framesPerHostBuffer,
+ PaUtilHostBufferSizeMode hostBufferSizeMode,
+ PaStreamCallback *streamCallback, void *userData );
+
+
+/** Terminate a buffer processor's representation. Deallocates any temporary
+ buffers allocated by PaUtil_InitializeBufferProcessor.
+
+ @param bufferProcessor The buffer processor structure to terminate.
+
+ @see PaUtil_InitializeBufferProcessor.
+*/
+void PaUtil_TerminateBufferProcessor( PaUtilBufferProcessor* bufferProcessor );
+
+
+/** Clear any internally buffered data. If you call
+ PaUtil_InitializeBufferProcessor in your OpenStream routine, make sure you
+ call PaUtil_ResetBufferProcessor in your StartStream call.
+
+ @param bufferProcessor The buffer processor to reset.
+*/
+void PaUtil_ResetBufferProcessor( PaUtilBufferProcessor* bufferProcessor );
+
+
+/** Retrieve the input latency of a buffer processor, in frames.
+
+ @param bufferProcessor The buffer processor examine.
+
+ @return The input latency introduced by the buffer processor, in frames.
+
+ @see PaUtil_GetBufferProcessorOutputLatencyFrames
+*/
+unsigned long PaUtil_GetBufferProcessorInputLatencyFrames( PaUtilBufferProcessor* bufferProcessor );
+
+/** Retrieve the output latency of a buffer processor, in frames.
+
+ @param bufferProcessor The buffer processor examine.
+
+ @return The output latency introduced by the buffer processor, in frames.
+
+ @see PaUtil_GetBufferProcessorInputLatencyFrames
+*/
+unsigned long PaUtil_GetBufferProcessorOutputLatencyFrames( PaUtilBufferProcessor* bufferProcessor );
+
+/*@}*/
+
+
+/** @name Host buffer pointer configuration
+
+ Functions to set host input and output buffers, used by both callback streams
+ and blocking read/write streams.
+*/
+/*@{*/
+
+
+/** Set the number of frames in the input host buffer(s) specified by the
+ PaUtil_Set*InputChannel functions.
+
+ @param bufferProcessor The buffer processor.
+
+ @param frameCount The number of host input frames. A 0 frameCount indicates to
+ use the framesPerHostBuffer value passed to PaUtil_InitializeBufferProcessor.
+
+ @see PaUtil_SetNoInput, PaUtil_SetInputChannel,
+ PaUtil_SetInterleavedInputChannels, PaUtil_SetNonInterleavedInputChannel
+*/
+void PaUtil_SetInputFrameCount( PaUtilBufferProcessor* bufferProcessor,
+ unsigned long frameCount );
+
+
+/** Indicate that no input is available. This function should be used when
+ priming the output of a full-duplex stream opened with the
+ paPrimeOutputBuffersUsingStreamCallback flag. Note that it is not necessary
+ to call this or any other PaUtil_Set*Input* functions for ouput-only streams.
+
+ @param bufferProcessor The buffer processor.
+*/
+void PaUtil_SetNoInput( PaUtilBufferProcessor* bufferProcessor );
+
+
+/** Provide the buffer processor with a pointer to a host input channel.
+
+ @param bufferProcessor The buffer processor.
+ @param channel The channel number.
+ @param data The buffer.
+ @param stride The stride from one sample to the next, in samples. For
+ interleaved host buffers, the stride will usually be the same as the number of
+ channels in the buffer.
+*/
+void PaUtil_SetInputChannel( PaUtilBufferProcessor* bufferProcessor,
+ unsigned int channel, void *data, unsigned int stride );
+
+
+/** Provide the buffer processor with a pointer to an number of interleaved
+ host input channels.
+
+ @param bufferProcessor The buffer processor.
+ @param firstChannel The first channel number.
+ @param data The buffer.
+ @param channelCount The number of interleaved channels in the buffer. If
+ channelCount is zero, the number of channels specified to
+ PaUtil_InitializeBufferProcessor will be used.
+*/
+void PaUtil_SetInterleavedInputChannels( PaUtilBufferProcessor* bufferProcessor,
+ unsigned int firstChannel, void *data, unsigned int channelCount );
+
+
+/** Provide the buffer processor with a pointer to one non-interleaved host
+ output channel.
+
+ @param bufferProcessor The buffer processor.
+ @param channel The channel number.
+ @param data The buffer.
+*/
+void PaUtil_SetNonInterleavedInputChannel( PaUtilBufferProcessor* bufferProcessor,
+ unsigned int channel, void *data );
+
+
+/** Use for the second buffer half when the input buffer is split in two halves.
+ @see PaUtil_SetInputFrameCount
+*/
+void PaUtil_Set2ndInputFrameCount( PaUtilBufferProcessor* bufferProcessor,
+ unsigned long frameCount );
+
+/** Use for the second buffer half when the input buffer is split in two halves.
+ @see PaUtil_SetInputChannel
+*/
+void PaUtil_Set2ndInputChannel( PaUtilBufferProcessor* bufferProcessor,
+ unsigned int channel, void *data, unsigned int stride );
+
+/** Use for the second buffer half when the input buffer is split in two halves.
+ @see PaUtil_SetInterleavedInputChannels
+*/
+void PaUtil_Set2ndInterleavedInputChannels( PaUtilBufferProcessor* bufferProcessor,
+ unsigned int firstChannel, void *data, unsigned int channelCount );
+
+/** Use for the second buffer half when the input buffer is split in two halves.
+ @see PaUtil_SetNonInterleavedInputChannel
+*/
+void PaUtil_Set2ndNonInterleavedInputChannel( PaUtilBufferProcessor* bufferProcessor,
+ unsigned int channel, void *data );
+
+
+/** Set the number of frames in the output host buffer(s) specified by the
+ PaUtil_Set*OutputChannel functions.
+
+ @param bufferProcessor The buffer processor.
+
+ @param frameCount The number of host output frames. A 0 frameCount indicates to
+ use the framesPerHostBuffer value passed to PaUtil_InitializeBufferProcessor.
+
+ @see PaUtil_SetOutputChannel, PaUtil_SetInterleavedOutputChannels,
+ PaUtil_SetNonInterleavedOutputChannel
+*/
+void PaUtil_SetOutputFrameCount( PaUtilBufferProcessor* bufferProcessor,
+ unsigned long frameCount );
+
+
+/** Indicate that the output will be discarded. This function should be used
+ when implementing the paNeverDropInput mode for full duplex streams.
+
+ @param bufferProcessor The buffer processor.
+*/
+void PaUtil_SetNoOutput( PaUtilBufferProcessor* bufferProcessor );
+
+
+/** Provide the buffer processor with a pointer to a host output channel.
+
+ @param bufferProcessor The buffer processor.
+ @param channel The channel number.
+ @param data The buffer.
+ @param stride The stride from one sample to the next, in samples. For
+ interleaved host buffers, the stride will usually be the same as the number of
+ channels in the buffer.
+*/
+void PaUtil_SetOutputChannel( PaUtilBufferProcessor* bufferProcessor,
+ unsigned int channel, void *data, unsigned int stride );
+
+
+/** Provide the buffer processor with a pointer to a number of interleaved
+ host output channels.
+
+ @param bufferProcessor The buffer processor.
+ @param firstChannel The first channel number.
+ @param data The buffer.
+ @param channelCount The number of interleaved channels in the buffer. If
+ channelCount is zero, the number of channels specified to
+ PaUtil_InitializeBufferProcessor will be used.
+*/
+void PaUtil_SetInterleavedOutputChannels( PaUtilBufferProcessor* bufferProcessor,
+ unsigned int firstChannel, void *data, unsigned int channelCount );
+
+
+/** Provide the buffer processor with a pointer to one non-interleaved host
+ output channel.
+
+ @param bufferProcessor The buffer processor.
+ @param channel The channel number.
+ @param data The buffer.
+*/
+void PaUtil_SetNonInterleavedOutputChannel( PaUtilBufferProcessor* bufferProcessor,
+ unsigned int channel, void *data );
+
+
+/** Use for the second buffer half when the output buffer is split in two halves.
+ @see PaUtil_SetOutputFrameCount
+*/
+void PaUtil_Set2ndOutputFrameCount( PaUtilBufferProcessor* bufferProcessor,
+ unsigned long frameCount );
+
+/** Use for the second buffer half when the output buffer is split in two halves.
+ @see PaUtil_SetOutputChannel
+*/
+void PaUtil_Set2ndOutputChannel( PaUtilBufferProcessor* bufferProcessor,
+ unsigned int channel, void *data, unsigned int stride );
+
+/** Use for the second buffer half when the output buffer is split in two halves.
+ @see PaUtil_SetInterleavedOutputChannels
+*/
+void PaUtil_Set2ndInterleavedOutputChannels( PaUtilBufferProcessor* bufferProcessor,
+ unsigned int firstChannel, void *data, unsigned int channelCount );
+
+/** Use for the second buffer half when the output buffer is split in two halves.
+ @see PaUtil_SetNonInterleavedOutputChannel
+*/
+void PaUtil_Set2ndNonInterleavedOutputChannel( PaUtilBufferProcessor* bufferProcessor,
+ unsigned int channel, void *data );
+
+/*@}*/
+
+
+/** @name Buffer processing functions for callback streams
+*/
+/*@{*/
+
+/** Commence processing a host buffer (or a pair of host buffers in the
+ full-duplex case) for a callback stream.
+
+ @param bufferProcessor The buffer processor.
+
+ @param timeInfo Timing information for the first sample of the host
+ buffer(s). This information may be adjusted when buffer adaption is being
+ performed.
+
+ @param callbackStatusFlags Flags indicating whether underruns and overruns
+ have occurred since the last time the buffer processor was called.
+*/
+void PaUtil_BeginBufferProcessing( PaUtilBufferProcessor* bufferProcessor,
+ PaStreamCallbackTimeInfo* timeInfo, PaStreamCallbackFlags callbackStatusFlags );
+
+
+/** Finish processing a host buffer (or a pair of host buffers in the
+ full-duplex case) for a callback stream.
+
+ @param bufferProcessor The buffer processor.
+
+ @param callbackResult On input, indicates a previous callback result, and on
+ exit, the result of the user stream callback, if it is called.
+ On entry callbackResult should contain one of { paContinue, paComplete, or
+ paAbort}. If paComplete is passed, the stream callback will not be called
+ but any audio that was generated by previous stream callbacks will be copied
+ to the output buffer(s). You can check whether the buffer processor's internal
+ buffer is empty by calling PaUtil_IsBufferProcessorOutputEmpty.
+
+ If the stream callback is called its result is stored in *callbackResult. If
+ the stream callback returns paComplete or paAbort, all output buffers will be
+ full of valid data - some of which may be zeros to account for data that
+ wasn't generated by the terminating callback.
+
+ @return The number of frames processed. This usually corresponds to the
+ number of frames specified by the PaUtil_Set*FrameCount functions, except in
+ the paUtilVariableHostBufferSizePartialUsageAllowed buffer size mode when a
+ smaller value may be returned.
+*/
+unsigned long PaUtil_EndBufferProcessing( PaUtilBufferProcessor* bufferProcessor,
+ int *callbackResult );
+
+
+/** Determine whether any callback generated output remains in the buffer
+ processor's internal buffers. This method may be used to determine when to
+ continue calling PaUtil_EndBufferProcessing() after the callback has returned
+ a callbackResult of paComplete.
+
+ @param bufferProcessor The buffer processor.
+
+ @return Returns non-zero when callback generated output remains in the internal
+ buffer and zero (0) when there internal buffer contains no callback generated
+ data.
+*/
+int PaUtil_IsBufferProcessorOutputEmpty( PaUtilBufferProcessor* bufferProcessor );
+
+/*@}*/
+
+
+/** @name Buffer processing functions for blocking read/write streams
+*/
+/*@{*/
+
+/** Copy samples from host input channels set up by the PaUtil_Set*InputChannels
+ functions to a user supplied buffer. This function is intended for use with
+ blocking read/write streams. Copies the minimum of the number of
+ user frames (specified by the frameCount parameter) and the number of available
+ host frames (specified in a previous call to SetInputFrameCount()).
+
+ @param bufferProcessor The buffer processor.
+
+ @param buffer A pointer to the user buffer pointer, or a pointer to a pointer
+ to an array of user buffer pointers for a non-interleaved stream. It is
+ important that this parameter points to a copy of the user buffer pointers,
+ not to the actual user buffer pointers, because this function updates the
+ pointers before returning.
+
+ @param frameCount The number of frames of data in the buffer(s) pointed to by
+ the buffer parameter.
+
+ @return The number of frames copied. The buffer pointer(s) pointed to by the
+ buffer parameter are advanced to point to the frame(s) following the last one
+ filled.
+*/
+unsigned long PaUtil_CopyInput( PaUtilBufferProcessor* bufferProcessor,
+ void **buffer, unsigned long frameCount );
+
+
+/* Copy samples from a user supplied buffer to host output channels set up by
+ the PaUtil_Set*OutputChannels functions. This function is intended for use with
+ blocking read/write streams. Copies the minimum of the number of
+ user frames (specified by the frameCount parameter) and the number of
+ host frames (specified in a previous call to SetOutputFrameCount()).
+
+ @param bufferProcessor The buffer processor.
+
+ @param buffer A pointer to the user buffer pointer, or a pointer to a pointer
+ to an array of user buffer pointers for a non-interleaved stream. It is
+ important that this parameter points to a copy of the user buffer pointers,
+ not to the actual user buffer pointers, because this function updates the
+ pointers before returning.
+
+ @param frameCount The number of frames of data in the buffer(s) pointed to by
+ the buffer parameter.
+
+ @return The number of frames copied. The buffer pointer(s) pointed to by the
+ buffer parameter are advanced to point to the frame(s) following the last one
+ copied.
+*/
+unsigned long PaUtil_CopyOutput( PaUtilBufferProcessor* bufferProcessor,
+ const void ** buffer, unsigned long frameCount );
+
+
+/* Zero samples in host output channels set up by the PaUtil_Set*OutputChannels
+ functions. This function is useful for flushing streams.
+ Zeros the minimum of frameCount and the number of host frames specified in a
+ previous call to SetOutputFrameCount().
+
+ @param bufferProcessor The buffer processor.
+
+ @param frameCount The maximum number of frames to zero.
+
+ @return The number of frames zeroed.
+*/
+unsigned long PaUtil_ZeroOutput( PaUtilBufferProcessor* bufferProcessor,
+ unsigned long frameCount );
+
+
+/*@}*/
+
+
+#ifdef __cplusplus
+}
+#endif /* __cplusplus */
+#endif /* PA_PROCESS_H */