Beatmup::Audio::SignalFragment Class Reference

A piece of sound. More...

#include <signal_fragment.h>

Inheritance diagram for Beatmup::Audio::SignalFragment:

Classes
class	DynamicsLookup
	Data structure allowing to plot efficiently audio signal graphs. More...
struct	Plot

Public Member Functions
	SignalFragment (AudioSampleFormat format, unsigned char channels, int samples)
virtual SignalFragment *	clone () const
sample8 *	getData ()
const AudioSampleFormat	getAudioFormat () const
msize	getSizeBytes () const
unsigned char	getBlockSize () const
unsigned char	getChannelCount () const
void	zero ()
bool	isDynamicsLookupAvailable () const
void	updateDynamicsLookup ()
template<typename sample >
void	measureDynamics (int time0, int time1, sample *min, sample *max, Signal::Meter::MeasuringMode mode)
	Measures dynamics from time0 to time1 in each channels separately. More...
Public Member Functions inherited from Beatmup::Fragments::Fragment
const int	getSampleCount () const
Fragment *	edit ()
	Enables editing of the current frame. More...
Fragment *	use ()
	References the frame when it is used one more time. More...
void	drop ()
	Dereferences the frame when it is not used any more. More...

Private Attributes
AudioSampleFormat	format
unsigned char	channelCount
	number of channels More...
unsigned char	blockSize
	size in bytes of a channelwise-multiplexed sample (block containing 1 sample per channel) More...
AlignedMemory	data
struct Beatmup::Audio::SignalFragment::Plot	plot

Additional Inherited Members
Protected Member Functions inherited from Beatmup::Fragments::Fragment
	Fragment ()
virtual	~Fragment ()
Protected Attributes inherited from Beatmup::Fragments::Fragment
int	sampleCount
	number of samples within this frame More...

Detailed Description

A piece of sound.

Audio signals in Beatmup can be fragmented. SignalFragment is a continuous piece of audio signal in memory. A lookup structure is implemented allowing to measure the signal dynamics efficiently.

FOR INTERNAL USE, should not be included anywhere except audio_signal.cpp

Definition at line 38 of file signal_fragment.h.

Constructor & Destructor Documentation

SignalFragment()

SignalFragment::SignalFragment	(	AudioSampleFormat	format,
		unsigned char	channels,
		int	samples
	)

Definition at line 240 of file signal_fragment.cpp.

                                                                                            :
    format(format), channelCount(channels)
{
    blockSize = channelCount * AUDIO_SAMPLE_SIZE[format];
    sampleCount = samples;
    data = AlignedMemory(getSizeBytes());
}

Member Function Documentation

clone()

SignalFragment * SignalFragment::clone ( ) const

virtual

Implements Beatmup::Fragments::Fragment.

Definition at line 249 of file signal_fragment.cpp.

                                            {
    SignalFragment* copy = new SignalFragment(format, channelCount, getSampleCount());
    memcpy(copy->data(), data(), getSizeBytes());
    copy->plot.fineLevelStep = plot.fineLevelStep;
    copy->plot.coarserLevelStep = plot.coarserLevelStep;
    // do not copy the lookup; it will be recomputed when needed
    copy->plot.lookup.disposeTree();
    return copy;
}

getData()

sample8* Beatmup::Audio::SignalFragment::getData ( )

inline

Definition at line 113 of file signal_fragment.h.

{ return data.ptr<sample8>(); }

getAudioFormat()

const AudioSampleFormat Beatmup::Audio::SignalFragment::getAudioFormat ( ) const

inline

Definition at line 114 of file signal_fragment.h.

{ return format; }

getSizeBytes()

msize Beatmup::Audio::SignalFragment::getSizeBytes ( ) const

inline

Definition at line 115 of file signal_fragment.h.

{ return getSampleCount() * blockSize; }

getBlockSize()

unsigned char Beatmup::Audio::SignalFragment::getBlockSize ( ) const

inline

Definition at line 116 of file signal_fragment.h.

{ return blockSize; }

getChannelCount()

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

inline

Definition at line 117 of file signal_fragment.h.

{ return channelCount; }

zero()

void SignalFragment::zero

(

)

Definition at line 260 of file signal_fragment.cpp.

                          {
    memchr(data(), 0, getSizeBytes());
}

isDynamicsLookupAvailable()

bool Beatmup::Audio::SignalFragment::isDynamicsLookupAvailable ( ) const

inline

Definition at line 121 of file signal_fragment.h.

{ return plot.lookup.isReady(); }

updateDynamicsLookup()

void SignalFragment::updateDynamicsLookup

(

)

Definition at line 265 of file signal_fragment.cpp.

                                          {
    plot.lookup.configureTree(
        channelCount,
        ilogb(sampleCount / channelCount / plot.fineLevelStep) / ilogb(plot.coarserLevelStep),
        plot.fineLevelStep,
        plot.coarserLevelStep
    );
 
    switch (format) {
    case Int8:
        plot.lookup.updateTree<sample8>(data.ptr<sample8>(), sampleCount);
        break;
    case Int16:
        plot.lookup.updateTree<sample16>(data.ptr<sample16>(), sampleCount);
        break;
    case Int32:
        plot.lookup.updateTree<sample32>(data.ptr<sample32>(), sampleCount);
        break;
    case Float32:
        plot.lookup.updateTree<sample32f>(data.ptr<sample32f>(), sampleCount);
        break;
    default:
        Insanity::insanity("Unknown sample format");
    }
}

measureDynamics()

template<typename sample >

template void SignalFragment::measureDynamics	(	int	time0,
		int	time1,
		sample *	min,
		sample *	max,
		Signal::Meter::MeasuringMode	mode
	)

Measures dynamics from time0 to time1 in each channels separately.

Parameters

time0	Start time
time1	Stop time
min	Channelwise multiplexed minima
max	Channelwise multiplexed maxima
mode	Measurement mode

Definition at line 292 of file signal_fragment.cpp.

                                                                                                                                            {
    BEATMUP_ASSERT_DEBUG(time0 <= time1);
    BEATMUP_ASSERT_DEBUG(AUDIO_SAMPLE_SIZE[format] == sizeof(sample));
 
    const bool useLookup =
        mode == Signal::Meter::MeasuringMode::approximateUsingLookup ||
        mode == Signal::Meter::MeasuringMode::preciseUsingLookupAndSamples;
 
    if (useLookup)
        RuntimeError::check(plot.lookup.isReady(), "Dynamics lookup is not ready");
 
    const void* sampleData = nullptr;
 
    // precise measurement
    if (
        mode == Signal::Meter::MeasuringMode::preciseUsingSamples ||
        mode == Signal::Meter::MeasuringMode::preciseUsingLookupAndSamples
    ) {
        sampleData = data();
    }
 
    // use lookup
    if (useLookup)
        plot.lookup.measure(time0, time1, min, max, (sample*)sampleData);
 
    // don't use lookup
    else {
        BEATMUP_ASSERT_DEBUG(sampleData);
        for (int ch = 0; ch < channelCount; ch++, min++, max++)
            measureMultiplexedChannelDynamics(
                (sample*)sampleData + time0*channelCount + ch,
                (sample*)sampleData + time1*channelCount + ch,
                channelCount,
                *min, *max
            );
    }
}

Member Data Documentation

format

AudioSampleFormat Beatmup::Audio::SignalFragment::format

private

Definition at line 97 of file signal_fragment.h.

channelCount

unsigned char Beatmup::Audio::SignalFragment::channelCount

private

number of channels

Definition at line 98 of file signal_fragment.h.

blockSize

unsigned char Beatmup::Audio::SignalFragment::blockSize

private

size in bytes of a channelwise-multiplexed sample (block containing 1 sample per channel)

Definition at line 99 of file signal_fragment.h.

data

AlignedMemory Beatmup::Audio::SignalFragment::data

private

Definition at line 100 of file signal_fragment.h.

plot

struct Beatmup::Audio::SignalFragment::Plot Beatmup::Audio::SignalFragment::plot

private

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

• core/audio/signal_fragment.h
• core/audio/signal_fragment.cpp