Audacity 3.2.0
Classes | Macros | Functions | Variables
AudioIO.cpp File Reference
#include "AudioIO.h"
#include "AudioIOExt.h"
#include "AudioIOListener.h"
#include "float_cast.h"
#include "DeviceManager.h"
#include <cfloat>
#include <math.h>
#include <stdlib.h>
#include <algorithm>
#include <numeric>
#include <optional>
#include <malloc.h>
#include "portaudio.h"
#include "pa_win_wasapi.h"
#include <wx/wxcrtvararg.h>
#include <wx/log.h>
#include <wx/time.h>
#include <wx/debug.h>
#include <wx/power.h>
#include "Channel.h"
#include "Meter.h"
#include "Mix.h"
#include "Resample.h"
#include "RingBuffer.h"
#include "Decibels.h"
#include "Prefs.h"
#include "Project.h"
#include "TransactionScope.h"
#include "RealtimeEffectManager.h"
#include "QualitySettings.h"
#include "BasicUI.h"
#include "Gain.h"
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struct  AudioIoCallback::TransportState


#define stackAllocate(T, count)   static_cast<T*>(alloca(count * sizeof(T)))


int audacityAudioCallback (const void *inputBuffer, void *outputBuffer, unsigned long framesPerBuffer, const PaStreamCallbackTimeInfo *timeInfo, PaStreamCallbackFlags statusFlags, void *userData)
static PaSampleFormat AudacityToPortAudioSampleFormat (sampleFormat format)
static void DoSoftwarePlaythrough (constSamplePtr inputBuffer, sampleFormat inputFormat, unsigned inputChannels, float *outputBuffer, unsigned long len)
void ClampBuffer (float *pBuffer, unsigned long len)


BoolSetting SoundActivatedRecord { "/AudioIO/SoundActivatedRecord", false }

Macro Definition Documentation

◆ stackAllocate

#define stackAllocate (   T,
)    static_cast<T*>(alloca(count * sizeof(T)))

Definition at line 2055 of file AudioIO.cpp.

Function Documentation

◆ audacityAudioCallback()

int audacityAudioCallback ( const void *  inputBuffer,
void *  outputBuffer,
unsigned long  framesPerBuffer,
const PaStreamCallbackTimeInfo *  timeInfo,
PaStreamCallbackFlags  statusFlags,
void *  userData 

brief The function which is called from PortAudio's callback thread context to collect and deliver audio for / from the sound device.

This covers recording, playback, and doing both simultaneously. It is also invoked to do monitoring and software playthrough. Note that dealing with the two buffers needs some care to ensure that the right things happen for all possible cases.

inputBufferBuffer of length framesPerBuffer containing samples from the sound card, or null if not capturing audio. Note that the data type will depend on the format of audio data that was chosen when the stream was created (so could be floats or various integers)
outputBufferUninitialised buffer of length framesPerBuffer which will be sent to the sound card after the callback, or null if not playing audio back.
framesPerBufferThe length of the playback and recording buffers
PaStreamCallbackTimeInfoPointer to PortAudio time information structure, which tells us how long we have been playing / recording
statusFlagsPortAudio stream status flags
userDatapointer to user-defined data structure. Provided for flexibility by PortAudio, but not used by Audacity - the data is stored in the AudioIO class instead.

Definition at line 2524 of file AudioIO.cpp.

2529 auto gAudioIO = AudioIO::Get();
2530 return gAudioIO->AudioCallback(
2531 static_cast<constSamplePtr>(inputBuffer),
2532 static_cast<float*>(outputBuffer), framesPerBuffer,
2533 timeInfo, statusFlags, userData);
const char * constSamplePtr
Definition: SampleFormat.h:58
static AudioIO * Get()
Definition: AudioIO.cpp:126

References AudioIO::Get().

Referenced by AudioIO::StartPortAudioStream().

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◆ AudacityToPortAudioSampleFormat()

static PaSampleFormat AudacityToPortAudioSampleFormat ( sampleFormat  format)

Definition at line 462 of file AudioIO.cpp.

464 switch(format) {
465 case int16Sample:
466 return paInt16;
467 case int24Sample:
468 return paInt24;
469 case floatSample:
470 default:
471 return paFloat32;
472 }
constexpr sampleFormat int16Sample
Definition: SampleFormat.h:43
constexpr sampleFormat floatSample
Definition: SampleFormat.h:45
constexpr sampleFormat int24Sample
Definition: SampleFormat.h:44

References floatSample, anonymous_namespace{ExportPCM.cpp}::format, int16Sample, and int24Sample.

Referenced by AudioIO::StartPortAudioStream().

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◆ ClampBuffer()

void ClampBuffer ( float *  pBuffer,
unsigned long  len 

Definition at line 2614 of file AudioIO.cpp.

2614 {
2615 for(unsigned i = 0; i < len; i++)
2616 pBuffer[i] = std::clamp(pBuffer[i], -1.0f, 1.0f);

Referenced by AudioIoCallback::FillOutputBuffers().

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◆ DoSoftwarePlaythrough()

static void DoSoftwarePlaythrough ( constSamplePtr  inputBuffer,
sampleFormat  inputFormat,
unsigned  inputChannels,
float *  outputBuffer,
unsigned long  len 

Definition at line 2505 of file AudioIO.cpp.

2511 for (unsigned int i=0; i < inputChannels; i++) {
2512 auto inputPtr = inputBuffer + (i * SAMPLE_SIZE(inputFormat));
2514 SamplesToFloats(inputPtr, inputFormat,
2515 outputBuffer + i, len, inputChannels, 2);
2516 }
2518 // One mono input channel goes to both output channels...
2519 if (inputChannels == 1)
2520 for (int i=0; i < len; i++)
2521 outputBuffer[2*i + 1] = outputBuffer[2*i];
void SamplesToFloats(constSamplePtr src, sampleFormat srcFormat, float *dst, size_t len, size_t srcStride, size_t dstStride)
Copy samples from any format into the widest format, which is 32 bit float, with no dithering.
#define SAMPLE_SIZE(SampleFormat)
Definition: SampleFormat.h:52

References SAMPLE_SIZE, and SamplesToFloats().

Referenced by AudioIoCallback::DoPlaythrough().

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Variable Documentation

◆ SoundActivatedRecord

BoolSetting SoundActivatedRecord { "/AudioIO/SoundActivatedRecord", false }