OpenShot Audio Library | OpenShotAudio 0.3.2
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juce::AudioSubsectionReader Class Reference

#include <juce_AudioSubsectionReader.h>

Inheritance diagram for juce::AudioSubsectionReader:
juce::AudioFormatReader

Public Member Functions

 AudioSubsectionReader (AudioFormatReader *sourceReader, int64 subsectionStartSample, int64 subsectionLength, bool deleteSourceWhenDeleted)
 
 ~AudioSubsectionReader () override
 
bool readSamples (int **destSamples, int numDestChannels, int startOffsetInDestBuffer, int64 startSampleInFile, int numSamples) override
 
void readMaxLevels (int64 startSample, int64 numSamples, Range< float > *results, int numChannelsToRead) override
 
virtual void readMaxLevels (int64 startSample, int64 numSamples, Range< float > *results, int numChannelsToRead)
 
virtual void readMaxLevels (int64 startSample, int64 numSamples, float &lowestLeft, float &highestLeft, float &lowestRight, float &highestRight)
 
- Public Member Functions inherited from juce::AudioFormatReader
virtual ~AudioFormatReader ()
 
const StringgetFormatName () const noexcept
 
bool read (float *const *destChannels, int numDestChannels, int64 startSampleInSource, int numSamplesToRead)
 
bool read (int *const *destChannels, int numDestChannels, int64 startSampleInSource, int numSamplesToRead, bool fillLeftoverChannelsWithCopies)
 
void read (AudioBuffer< float > *buffer, int startSampleInDestBuffer, int numSamples, int64 readerStartSample, bool useReaderLeftChan, bool useReaderRightChan)
 
int64 searchForLevel (int64 startSample, int64 numSamplesToSearch, double magnitudeRangeMinimum, double magnitudeRangeMaximum, int minimumConsecutiveSamples)
 
virtual AudioChannelSet getChannelLayout ()
 

Additional Inherited Members

- Public Attributes inherited from juce::AudioFormatReader
double sampleRate = 0
 
unsigned int bitsPerSample = 0
 
int64 lengthInSamples = 0
 
unsigned int numChannels = 0
 
bool usesFloatingPointData = false
 
StringPairArray metadataValues
 
InputStreaminput
 
- Protected Member Functions inherited from juce::AudioFormatReader
 AudioFormatReader (InputStream *sourceStream, const String &formatName)
 
- Static Protected Member Functions inherited from juce::AudioFormatReader
static void clearSamplesBeyondAvailableLength (int **destChannels, int numDestChannels, int startOffsetInDestBuffer, int64 startSampleInFile, int &numSamples, int64 fileLengthInSamples)
 

Detailed Description

This class is used to wrap an AudioFormatReader and only read from a subsection of the file.

So if you have a reader which can read a 1000 sample file, you could wrap it in one of these to only access, e.g. samples 100 to 200, and any samples outside that will come back as 0. Accessing sample 0 from this reader will actually read the first sample from the other's subsection, which might be at a non-zero position.

See also
AudioFormatReader

Definition at line 45 of file juce_AudioSubsectionReader.h.

Constructor & Destructor Documentation

◆ AudioSubsectionReader()

juce::AudioSubsectionReader::AudioSubsectionReader ( AudioFormatReader sourceReader,
int64  subsectionStartSample,
int64  subsectionLength,
bool  deleteSourceWhenDeleted 
)

Creates an AudioSubsectionReader for a given data source.

Parameters
sourceReaderthe source reader from which we'll be taking data
subsectionStartSamplethe sample within the source reader which will be mapped onto sample 0 for this reader.
subsectionLengththe number of samples from the source that will make up the subsection. If this reader is asked for any samples beyond this region, it will return zero.
deleteSourceWhenDeletedif true, the sourceReader object will be deleted when this object is deleted.

Definition at line 30 of file juce_AudioSubsectionReader.cpp.

◆ ~AudioSubsectionReader()

juce::AudioSubsectionReader::~AudioSubsectionReader ( )
override

Destructor.

Definition at line 47 of file juce_AudioSubsectionReader.cpp.

Member Function Documentation

◆ readMaxLevels() [1/3]

void juce::AudioFormatReader::readMaxLevels ( int64  startSample,
int64  numSamples,
float lowestLeft,
float highestLeft,
float lowestRight,
float highestRight 
)
virtual

Finds the highest and lowest sample levels from a section of the audio stream.

This will read a block of samples from the stream, and measure the highest and lowest sample levels from the channels in that section, returning these as normalised floating-point levels.

Parameters
startSamplethe offset into the audio stream to start reading from. It's ok for this to be beyond the start or end of the stream.
numSampleshow many samples to read
lowestLefton return, this is the lowest absolute sample from the left channel
highestLefton return, this is the highest absolute sample from the left channel
lowestRighton return, this is the lowest absolute sample from the right channel (if there is one)
highestRighton return, this is the highest absolute sample from the right channel (if there is one)
See also
read

Reimplemented from juce::AudioFormatReader.

Definition at line 187 of file juce_AudioFormatReader.cpp.

◆ readMaxLevels() [2/3]

void juce::AudioFormatReader::readMaxLevels ( int64  startSample,
int64  numSamples,
Range< float > *  results,
int  numChannelsToRead 
)
virtual

Finds the highest and lowest sample levels from a section of the audio stream.

This will read a block of samples from the stream, and measure the highest and lowest sample levels from the channels in that section, returning these as normalised floating-point levels.

Parameters
startSamplethe offset into the audio stream to start reading from. It's ok for this to be beyond the start or end of the stream.
numSampleshow many samples to read
resultsthis array will be filled with Range values for each channel. The array must contain numChannels elements.
numChannelsToReadthe number of channels of data to scan. This must be more than zero, but not more than the total number of channels that the reader contains
See also
read

Reimplemented from juce::AudioFormatReader.

Definition at line 167 of file juce_AudioFormatReader.cpp.

◆ readMaxLevels() [3/3]

void juce::AudioSubsectionReader::readMaxLevels ( int64  startSample,
int64  numSamples,
Range< float > *  results,
int  numChannelsToRead 
)
overridevirtual

Finds the highest and lowest sample levels from a section of the audio stream.

This will read a block of samples from the stream, and measure the highest and lowest sample levels from the channels in that section, returning these as normalised floating-point levels.

Parameters
startSamplethe offset into the audio stream to start reading from. It's ok for this to be beyond the start or end of the stream.
numSampleshow many samples to read
resultsthis array will be filled with Range values for each channel. The array must contain numChannels elements.
numChannelsToReadthe number of channels of data to scan. This must be more than zero, but not more than the total number of channels that the reader contains
See also
read

Reimplemented from juce::AudioFormatReader.

Definition at line 64 of file juce_AudioSubsectionReader.cpp.

◆ readSamples()

bool juce::AudioSubsectionReader::readSamples ( int **  destChannels,
int  numDestChannels,
int  startOffsetInDestBuffer,
int64  startSampleInFile,
int  numSamples 
)
overridevirtual

Subclasses must implement this method to perform the low-level read operation.

Callers should use read() instead of calling this directly.

Parameters
destChannelsthe array of destination buffers to fill. Some of these pointers may be null
numDestChannelsthe number of items in the destChannels array. This value is guaranteed not to be greater than the number of channels that this reader object contains
startOffsetInDestBufferthe number of samples from the start of the dest data at which to begin writing
startSampleInFilethe number of samples into the source data at which to begin reading. This value is guaranteed to be >= 0.
numSamplesthe number of samples to read

Implements juce::AudioFormatReader.

Definition at line 54 of file juce_AudioSubsectionReader.cpp.


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