#include <stdio.h>
#include <memory.h>
#include <string.h>
#include <assert.h>
#include "portaudio.h"
#include "pa_util.h"
#include "pa_endianness.h"
#include "pa_types.h"
#include "pa_hostapi.h"
#include "pa_stream.h"
#include "pa_trace.h"
#include "pa_debugprint.h"
Implements the functions defined in the PortAudio API, checks for some parameter and state inconsistencies and forwards API requests to specific Host API implementations (via the interface declared in pa_hostapi.h), and Streams (via the interface declared in pa_stream.h).
This file handles initialization and termination of Host API implementations via initializers stored in the paHostApiInitializers global variable.
Some utility functions declared in pa_util.h are implemented in this file.
All PortAudio API functions can be conditionally compiled with logging code. To compile with logging, define the PA_LOG_API_CALLS precompiler symbol.
#define PA_IS_INITIALISED_ (initializationCount_ != 0) |
#define PA_LAST_HOST_ERROR_TEXT_LENGTH_ 1024 |
#define PA_VERSION_ 1899 |
#define PA_VERSION_TEXT_ "PortAudio V19-devel (built " __DATE__ ")" |
Terminates audio processing immediately without waiting for pending buffers to complete.
Closes an audio stream. If the audio stream is active it discards any pending buffers as if Pa_AbortStream() had been called.
PaHostApiIndex Pa_GetDefaultHostApi | ( | void | ) |
Retrieve the index of the default host API. The default host API will be the lowest common denominator host API on the current platform and is unlikely to provide the best performance.
PaDeviceIndex Pa_GetDefaultInputDevice | ( | void | ) |
Retrieve the index of the default input device. The result can be used in the inputDevice parameter to Pa_OpenStream().
PaDeviceIndex Pa_GetDefaultOutputDevice | ( | void | ) |
Retrieve the index of the default output device. The result can be used in the outputDevice parameter to Pa_OpenStream().
set PA_RECOMMENDED_OUTPUT_DEVICE=1The user should first determine the available device ids by using the supplied application "pa_devs".
PaDeviceIndex Pa_GetDeviceCount | ( | void | ) |
Retrieve the number of available devices. The number of available devices may be zero.
const PaDeviceInfo* Pa_GetDeviceInfo | ( | PaDeviceIndex | device | ) |
Retrieve a pointer to a PaDeviceInfo structure containing information about the specified device.
device | A valid device index in the range 0 to (Pa_GetDeviceCount()-1) |
const char* Pa_GetErrorText | ( | PaError | errorCode | ) |
Translate the supplied PortAudio error code into a human readable message.
PaHostApiIndex Pa_GetHostApiCount | ( | void | ) |
Retrieve the number of available host APIs. Even if a host API is available it may have no devices available.
const PaHostApiInfo* Pa_GetHostApiInfo | ( | PaHostApiIndex | hostApi | ) |
Retrieve a pointer to a structure containing information about a specific host Api.
hostApi | A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1) |
const PaHostErrorInfo* Pa_GetLastHostErrorInfo | ( | void | ) |
Return information about the last host error encountered. The error information returned by Pa_GetLastHostErrorInfo() will never be modified asyncronously by errors occurring in other PortAudio owned threads (such as the thread that manages the stream callback.)
This function is provided as a last resort, primarily to enhance debugging by providing clients with access to all available error information.
PaError Pa_GetSampleSize | ( | PaSampleFormat | format | ) |
Retrieve the size of a given sample format in bytes.
double Pa_GetStreamCpuLoad | ( | PaStream * | stream | ) |
Retrieve CPU usage information for the specified stream. The "CPU Load" is a fraction of total CPU time consumed by a callback stream's audio processing routines including, but not limited to the client supplied stream callback. This function does not work with blocking read/write streams.
This function may be called from the stream callback function or the application.
const PaStreamInfo* Pa_GetStreamInfo | ( | PaStream * | stream | ) |
Retrieve a pointer to a PaStreamInfo structure containing information about the specified stream.
stream | A pointer to an open stream previously created with Pa_OpenStream. |
signed long Pa_GetStreamReadAvailable | ( | PaStream * | stream | ) |
Retrieve the number of frames that can be read from the stream without waiting.
Determine the current time for the stream according to the same clock used to generate buffer timestamps. This time may be used for syncronising other events to the audio stream, for example synchronizing audio to MIDI.
signed long Pa_GetStreamWriteAvailable | ( | PaStream * | stream | ) |
Retrieve the number of frames that can be written to the stream without waiting.
int Pa_GetVersion | ( | void | ) |
Retrieve the release number of the currently running PortAudio build, eg 1900.
const char* Pa_GetVersionText | ( | void | ) |
Retrieve a textual description of the current PortAudio build, eg "PortAudio V19-devel 13 October 2002".
PaDeviceIndex Pa_HostApiDeviceIndexToDeviceIndex | ( | PaHostApiIndex | hostApi, | |
int | hostApiDeviceIndex | |||
) |
Convert a host-API-specific device index to standard PortAudio device index. This function may be used in conjunction with the deviceCount field of PaHostApiInfo to enumerate all devices for the specified host API.
hostApi | A valid host API index ranging from 0 to (Pa_GetHostApiCount()-1) | |
hostApiDeviceIndex | A valid per-host device index in the range 0 to (Pa_GetHostApiInfo(hostApi)->deviceCount-1) |
A paInvalidDevice error code indicates that the hostApiDeviceIndex parameter is out of range.
PaHostApiIndex Pa_HostApiTypeIdToHostApiIndex | ( | PaHostApiTypeId | type | ) |
Convert a static host API unique identifier, into a runtime host API index.
type | A unique host API identifier belonging to the PaHostApiTypeId enumeration. |
PaError Pa_Initialize | ( | void | ) |
Library initialization function - call this before using PortAudio. This function initialises internal data structures and prepares underlying host APIs for use. With the exception of Pa_GetVersion(), Pa_GetVersionText(), and Pa_GetErrorText(), this function MUST be called before using any other PortAudio API functions.
If Pa_Initialize() is called multiple times, each successful call must be matched with a corresponding call to Pa_Terminate(). Pairs of calls to Pa_Initialize()/Pa_Terminate() may overlap, and are not required to be fully nested.
Note that if Pa_Initialize() returns an error code, Pa_Terminate() should NOT be called.
PaError Pa_IsFormatSupported | ( | const PaStreamParameters * | inputParameters, | |
const PaStreamParameters * | outputParameters, | |||
double | sampleRate | |||
) |
Determine whether it would be possible to open a stream with the specified parameters.
inputParameters | A structure that describes the input parameters used to open a stream. The suggestedLatency field is ignored. See PaStreamParameters for a description of these parameters. inputParameters must be NULL for output-only streams. | |
outputParameters | A structure that describes the output parameters used to open a stream. The suggestedLatency field is ignored. See PaStreamParameters for a description of these parameters. outputParameters must be NULL for input-only streams. | |
sampleRate | The required sampleRate. For full-duplex streams it is the sample rate for both input and output |
Determine whether the stream is active. A stream is active after a successful call to Pa_StartStream(), until it becomes inactive either as a result of a call to Pa_StopStream() or Pa_AbortStream(), or as a result of a return value other than paContinue from the stream callback. In the latter case, the stream is considered inactive after the last buffer has finished playing.
Determine whether the stream is stopped. A stream is considered to be stopped prior to a successful call to Pa_StartStream and after a successful call to Pa_StopStream or Pa_AbortStream. If a stream callback returns a value other than paContinue the stream is NOT considered to be stopped.
PaError Pa_OpenDefaultStream | ( | PaStream ** | stream, | |
int | numInputChannels, | |||
int | numOutputChannels, | |||
PaSampleFormat | sampleFormat, | |||
double | sampleRate, | |||
unsigned long | framesPerBuffer, | |||
PaStreamCallback * | streamCallback, | |||
void * | userData | |||
) |
A simplified version of Pa_OpenStream() that opens the default input and/or output devices.
stream | The address of a PaStream pointer which will receive a pointer to the newly opened stream. | |
numInputChannels | The number of channels of sound that will be supplied to the stream callback or returned by Pa_ReadStream. It can range from 1 to the value of maxInputChannels in the PaDeviceInfo record for the default input device. If 0 the stream is opened as an output-only stream. | |
numOutputChannels | The number of channels of sound to be delivered to the stream callback or passed to Pa_WriteStream. It can range from 1 to the value of maxOutputChannels in the PaDeviceInfo record for the default output dvice. If 0 the stream is opened as an output-only stream. | |
sampleFormat | The sample format of both the input and output buffers provided to the callback or passed to and from Pa_ReadStream and Pa_WriteStream. sampleFormat may be any of the formats described by the PaSampleFormat enumeration. | |
sampleRate | Same as Pa_OpenStream parameter of the same name. | |
framesPerBuffer | Same as Pa_OpenStream parameter of the same name. | |
streamCallback | Same as Pa_OpenStream parameter of the same name. | |
userData | Same as Pa_OpenStream parameter of the same name. |
PaError Pa_OpenStream | ( | PaStream ** | stream, | |
const PaStreamParameters * | inputParameters, | |||
const PaStreamParameters * | outputParameters, | |||
double | sampleRate, | |||
unsigned long | framesPerBuffer, | |||
PaStreamFlags | streamFlags, | |||
PaStreamCallback * | streamCallback, | |||
void * | userData | |||
) |
Opens a stream for either input, output or both.
stream | The address of a PaStream pointer which will receive a pointer to the newly opened stream. | |
inputParameters | A structure that describes the input parameters used by the opened stream. See PaStreamParameters for a description of these parameters. inputParameters must be NULL for output-only streams. | |
outputParameters | A structure that describes the output parameters used by the opened stream. See PaStreamParameters for a description of these parameters. outputParameters must be NULL for input-only streams. | |
sampleRate | The desired sampleRate. For full-duplex streams it is the sample rate for both input and output | |
framesPerBuffer | The number of frames passed to the stream callback function, or the preferred block granularity for a blocking read/write stream. The special value paFramesPerBufferUnspecified (0) may be used to request that the stream callback will recieve an optimal (and possibly varying) number of frames based on host requirements and the requested latency settings. Note: With some host APIs, the use of non-zero framesPerBuffer for a callback stream may introduce an additional layer of buffering which could introduce additional latency. PortAudio guarantees that the additional latency will be kept to the theoretical minimum however, it is strongly recommended that a non-zero framesPerBuffer value only be used when your algorithm requires a fixed number of frames per stream callback. | |
streamFlags | Flags which modify the behaviour of the streaming process. This parameter may contain a combination of flags ORed together. Some flags may only be relevant to certain buffer formats. | |
streamCallback | A pointer to a client supplied function that is responsible for processing and filling input and output buffers. If this parameter is NULL the stream will be opened in 'blocking read/write' mode. In blocking mode, the client can receive sample data using Pa_ReadStream and write sample data using Pa_WriteStream, the number of samples that may be read or written without blocking is returned by Pa_GetStreamReadAvailable and Pa_GetStreamWriteAvailable respectively. | |
userData | A client supplied pointer which is passed to the stream callback function. It could for example, contain a pointer to instance data necessary for processing the audio buffers. This parameter is ignored if streamCallback is NULL. |
Read samples from an input stream. The function doesn't return until the entire buffer has been filled - this may involve waiting for the operating system to supply the data.
stream | A pointer to an open stream previously created with Pa_OpenStream. | |
buffer | A pointer to a buffer of sample frames. The buffer contains samples in the format specified by the inputParameters->sampleFormat field used to open the stream, and the number of channels specified by inputParameters->numChannels. If non-interleaved samples were requested, buffer is a pointer to the first element of an array of non-interleaved buffer pointers, one for each channel. | |
frames | The number of frames to be read into buffer. This parameter is not constrained to a specific range, however high performance applications will want to match this parameter to the framesPerBuffer parameter used when opening the stream. |
PaError Pa_SetStreamFinishedCallback | ( | PaStream * | stream, | |
PaStreamFinishedCallback * | streamFinishedCallback | |||
) |
Register a stream finished callback function which will be called when the stream becomes inactive. See the description of PaStreamFinishedCallback for further details about when the callback will be called.
stream | a pointer to a PaStream that is in the stopped state - if the stream is not stopped, the stream's finished callback will remain unchanged and an error code will be returned. | |
streamFinishedCallback | a pointer to a function with the same signature as PaStreamFinishedCallback, that will be called when the stream becomes inactive. Passing NULL for this parameter will un-register a previously registered stream finished callback function. |
Terminates audio processing. It waits until all pending audio buffers have been played before it returns.
PaError Pa_Terminate | ( | void | ) |
Library termination function - call this when finished using PortAudio. This function deallocates all resources allocated by PortAudio since it was initializied by a call to Pa_Initialize(). In cases where Pa_Initialise() has been called multiple times, each call must be matched with a corresponding call to Pa_Terminate(). The final matching call to Pa_Terminate() will automatically close any PortAudio streams that are still open.
Pa_Terminate() MUST be called before exiting a program which uses PortAudio. Failure to do so may result in serious resource leaks, such as audio devices not being available until the next reboot.
Write samples to an output stream. This function doesn't return until the entire buffer has been consumed - this may involve waiting for the operating system to consume the data.
stream | A pointer to an open stream previously created with Pa_OpenStream. | |
buffer | A pointer to a buffer of sample frames. The buffer contains samples in the format specified by the outputParameters->sampleFormat field used to open the stream, and the number of channels specified by outputParameters->numChannels. If non-interleaved samples were requested, buffer is a pointer to the first element of an array of non-interleaved buffer pointers, one for each channel. | |
frames | The number of frames to be written from buffer. This parameter is not constrained to a specific range, however high performance applications will want to match this parameter to the framesPerBuffer parameter used when opening the stream. |
PaError PaUtil_DeviceIndexToHostApiDeviceIndex | ( | PaDeviceIndex * | hostApiDevice, | |
PaDeviceIndex | device, | |||
struct PaUtilHostApiRepresentation * | hostApi | |||
) |
Convert a PortAudio device index into a host API specific device index.
hostApiDevice | Pointer to a device index, on success this will recieve the converted device index value. | |
device | The PortAudio device index to convert. | |
hostApi | The host api which the index should be converted for. |
PaError PaUtil_GetHostApiRepresentation | ( | struct PaUtilHostApiRepresentation ** | hostApi, | |
PaHostApiTypeId | type | |||
) |
Retrieve a specific host API representation. This function can be used by implementations to retrieve a pointer to their representation in host api specific extension functions which aren't passed a rep pointer by pa_front.c.
hostApi | A pointer to a host API represenation pointer. Apon success this will receive the requested representation pointer. | |
type | A valid host API type identifier. |
void PaUtil_SetLastHostErrorInfo | ( | PaHostApiTypeId | hostApiType, | |
long | errorCode, | |||
const char * | errorText | |||
) |
Set the host error information returned by Pa_GetLastHostErrorInfo. This function and the paUnanticipatedHostError error code should be used as a last resort. Implementors should use existing PA error codes where possible, or nominate new ones. Note that at it is always better to use PaUtil_SetLastHostErrorInfo() and paUnanticipatedHostError than to return an ambiguous or inaccurate PaError code.
hostApiType | The host API which encountered the error (ie of the caller) | |
errorCode | The error code returned by the native API function. | |
errorText | A string describing the error. PaUtil_SetLastHostErrorInfo makes a copy of the string, so it is not necessary for the pointer to remain valid after the call to PaUtil_SetLastHostErrorInfo() returns. |
Check that the stream pointer is valid.