An audio signal. More...

#include <signal.h>

Inheritance diagram for Beatmup::Audio::Signal:

Classes
class	IncompatibleFormat
	Communicates an error when inserting a incompatible fragment into a Signal. More...

class	Meter
	Signal dynamics meter. More...

class	Pointer
	Implements a Sequence::Pointer for audio signals. More...

class	Reader
	Provides reading access to the signal. More...

class	Source
	Audio::Source reading samples from a given Signal. More...

class	Writer
	Provides writing access to the signal. More...

Public Member Functions
	Signal (Context &context, AudioSampleFormat format, int sampleRate, unsigned char channels, float defaultFragmentLenSec=DEFAULT_FRAGMENT_LENGTH_SEC)
	Creates an empty signal. More...

void	insert (const Signal &signal, dtime time)
	Inserts a Signal into the current signal at a specific time moment. More...

void	reserve (dtime length)
	Prolongates the sequence if necessary, to ensure given length. More...

void	saveWAV (const char *filename)
	Stores the signal to a PCM-encoded WAV file. More...

unsigned char	getChannelCount () const

AudioSampleFormat	getSampleFormat () const

Context &	getContext () const

Public Member Functions inherited from Beatmup::Fragments::SequenceToolkit< Signal >
Signal *	copy (dtime fromTime, dtime toTime) const

Public Member Functions inherited from Beatmup::Fragments::Sequence
const dtime	getDuration () const
	Returns sequence duration in number of samples. More...

bool	isEmpty () const
	Returns `true` if sequence contains no samples. More...

void	clear ()
	Removes the content of the sequence making it empty (of zero duration). More...

void	shrink (dtime timeLeft, dtime timeRight)
	Shrinks the sequence to given time bounds. More...

Sequence *	copy (dtime fromTime, dtime toTime) const
	Copies a given piece of the current sequence into new Sequence. More...

void	insert (const Sequence &sequence, dtime time)
	Inserts a Sequence at a given position in time. More...

void	remove (dtime fromTime, dtime toTime)
	Erases a part of the sequence between two given time moments. More...

void	split (dtime time, Sequence left, Sequence right) const
	Splits the sequence in two at a specific time. More...

Public Member Functions inherited from Beatmup::Object
virtual	~Object ()

Static Public Member Functions
static Signal *	loadWAV (Context &ctx, const char *fileName)

static Signal *	loadWAV (Context &ctx, InputStream &inputStream)

Static Public Attributes
static const int	DEFAULT_FRAGMENT_LENGTH_SEC = 5

Protected Member Functions
virtual Signal *	createEmpty () const
	Initializes an empty sequence, used to bootstrap copying operations. More...

Protected Member Functions inherited from Beatmup::Fragments::Sequence
	Sequence ()

virtual	~Sequence ()

void	concatenate (Fragment &fragment, dtime offset, dtime length)
	Adds a new fragment at the end of the sequence. More...

void	syncPointers ()
	Resets pointers once the sequence changes to keep them consistent. More...

Private Attributes
Context &	ctx

AudioSampleFormat	format
	sample format More...

const dtime	defaultFragmentSize

int	sampleRate
	sampling frequency More...

unsigned char	channelCount
	number of channels More...

Detailed Description

An audio signal.

Definition at line 36 of file signal.h.

Constructor & Destructor Documentation

◆ Signal()

Signal::Signal	(	Context &	context,
		AudioSampleFormat	format,
		int	sampleRate,
		unsigned char	channels,
		float	defaultFragmentLenSec = `DEFAULT_FRAGMENT_LENGTH_SEC`
	)

Creates an empty signal.

Parameters

context	A Context instance the new signal is associated to
format	Sample format of the new signal
sampleRate	Sample rate, Hz
channels	Number of channels
defaultFragmentLenSec	Default fragment length in seconds

Definition at line 36 of file signal.cpp.

                                                                                                                               :
     ctx(context),
     format(format),
     defaultFragmentSize(floorf_fast(defaultFragmentLenSec * sampleRate)),
     sampleRate(sampleRate),
     channelCount(channels)
 {
     BEATMUP_ASSERT_DEBUG(defaultFragmentSize > 0);
 }

Member Function Documentation

◆ createEmpty()

Signal * Signal::createEmpty ( ) const

protectedvirtual

Initializes an empty sequence, used to bootstrap copying operations.

Implements Beatmup::Fragments::Sequence.

Definition at line 31 of file signal.cpp.

                                   {
     return new Signal(ctx, format, sampleRate, channelCount, (float)defaultFragmentSize / sampleRate);
 }

◆ insert()

void Signal::insert	(	const Signal &	signal,
		dtime	time
	)

Inserts a Signal into the current signal at a specific time moment.

Parameters

signal	The signal to insert
time	The time moment to insert the signal at

Definition at line 47 of file signal.cpp.

                                                     {
     if (signal.channelCount != channelCount || signal.format != format)
         throw Signal::IncompatibleFormat(signal, *this);
     Sequence::insert(signal, time);
 }

◆ reserve()

void Signal::reserve ( dtime length )

Prolongates the sequence if necessary, to ensure given length.

Definition at line 54 of file signal.cpp.

                                  {
     int curDur;
     while ((curDur = getDuration()) < length) {
         SignalFragment* newbie = new SignalFragment(format, channelCount, defaultFragmentSize);
         newbie->zero();
         concatenate(*newbie, 0, std::min(defaultFragmentSize, length - curDur));
     }
 }

◆ saveWAV()

void Signal::saveWAV ( const char * filename )

Stores the signal to a PCM-encoded WAV file.

Definition at line 117 of file signal.cpp.

                                          {
     // open file
     std::ofstream file(filename, std::ofstream::out | std::ofstream::binary | std::ofstream::trunc);
     if (!file.is_open())
         throw IOError(filename, "Unable to open for writing");
  
     // init and write header
     unsigned char sampleSize = AUDIO_SAMPLE_SIZE[format];
     WAV::Header header;
     header.set(sampleRate, sampleSize * 8, channelCount, getDuration() * channelCount * sampleSize);
     file.write((char*)&header, sizeof(header));
  
     // write out
     Reader pointer(*this, 0);
     while (pointer.hasData() && !file.eof()) {
         if (file.fail())
             throw IOError(filename, "Failed while writing");
         const void* data;
         dtime length = pointer.acquireBuffer(data);
         file.write((const char*)data, length * channelCount * sampleSize);
         pointer.releaseBuffer();
         pointer.jump(length);
     }
 }

◆ loadWAV() [1/2]

Signal * Signal::loadWAV	(	Context &	ctx,
		const char *	fileName
	)

static

Definition at line 64 of file signal.cpp.

                                                           {
     // open file
     FileInputStream stream(filename);
     if (!stream.isOpen())
         throw IOError(filename, "Unable to open for reading");
     return Signal::loadWAV(ctx, stream);
 }

◆ loadWAV() [2/2]

Signal * Signal::loadWAV	(	Context &	ctx,
		InputStream &	inputStream
	)

static

Definition at line 72 of file signal.cpp.

                                                          {
     // read header
     WAV::Header header;
     stream(&header, sizeof(header));
     WAV::InvalidWavFile::check(header);
  
     // get sample format
     AudioSampleFormat format;
     switch (header.bitsPerSample) {
         case 8:
             format = Int8;
             break;
         case 16:
             format = Int16;
             break;
         case 32:
             format = Int32;
             break;
         default:
             throw WAV::InvalidWavFile("Incorrect WAV file: unsupported BPS");
     }
  
     // check number of channels (insanity check, basically)
     if (header.numChannels <= 0 || header.numChannels > 255)
         throw WAV::InvalidWavFile("Incorrect WAV file: unsupported channel count");
  
     // create signal
     Signal* signal = new Signal(ctx, format, header.sampleRate, header.numChannels);
     dtime totalTime = header.dataSizeBytes / (header.numChannels * header.bitsPerSample / 8);
     signal->reserve(totalTime);
  
     // read data using pointer
     Writer pointer(*signal, 0);
     while (pointer.hasData() && !stream.eof()) {
         void* data;
         dtime length = pointer.acquireBuffer(data);
         stream(data, length * header.numChannels * AUDIO_SAMPLE_SIZE[format]);
         pointer.releaseBuffer();
         pointer.jump(length);
     }
  
     return signal;
 }

◆ getChannelCount()

unsigned char Beatmup::Audio::Signal::getChannelCount ( ) const

inline

Returns: number of channels in the signal.

Definition at line 232 of file signal.h.

232 { return channelCount; }

◆ getSampleFormat()

AudioSampleFormat Beatmup::Audio::Signal::getSampleFormat ( ) const

inline

Returns: sample format of the signal.

Definition at line 237 of file signal.h.

237 { return format; }

◆ getContext()

Context& Beatmup::Audio::Signal::getContext ( ) const

inline

Returns: a Context instance the signal is attached to.

Definition at line 242 of file signal.h.

242 { return ctx; }

Member Data Documentation

◆ ctx

Context& Beatmup::Audio::Signal::ctx

private

Definition at line 185 of file signal.h.

◆ format

AudioSampleFormat Beatmup::Audio::Signal::format

private

sample format

Definition at line 187 of file signal.h.

◆ defaultFragmentSize

const dtime Beatmup::Audio::Signal::defaultFragmentSize

private

Definition at line 189 of file signal.h.

◆ sampleRate

int Beatmup::Audio::Signal::sampleRate

private

sampling frequency

Definition at line 190 of file signal.h.

◆ channelCount

unsigned char Beatmup::Audio::Signal::channelCount

private

number of channels

Definition at line 191 of file signal.h.

◆ DEFAULT_FRAGMENT_LENGTH_SEC

const int Beatmup::Audio::Signal::DEFAULT_FRAGMENT_LENGTH_SEC = 5

static

Definition at line 197 of file signal.h.

The documentation for this class was generated from the following files:

core/audio/signal.h
core/audio/signal.cpp

Classes

Public Member Functions

Static Public Member Functions

Static Public Attributes

Protected Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Signal()

Member Function Documentation

◆ createEmpty()

◆ insert()

◆ reserve()

◆ saveWAV()

◆ loadWAV() [1/2]

◆ loadWAV() [2/2]

◆ getChannelCount()

◆ getSampleFormat()

◆ getContext()

Member Data Documentation

◆ ctx

◆ format

◆ defaultFragmentSize

◆ sampleRate

◆ channelCount

◆ DEFAULT_FRAGMENT_LENGTH_SEC