Writes samples to an audio file stream.
A subclass that writes a specific type of audio format will be created by an AudioFormat object.
After creating one of these with the AudioFormat::createWriterFor() method you can call its write() method to store the samples, and then delete it.
Classes | |
| class | ThreadedWriter |
| Provides a FIFO for an AudioFormatWriter, allowing you to push incoming data into a buffer which will be flushed to disk by a background thread. More... | |
| struct | WriteHelper |
| Used by AudioFormatWriter subclasses to copy data to different formats. More... | |
Public Types | |
| using | Options = AudioFormatWriterOptions |
Public Member Functions | |
| virtual | ~AudioFormatWriter () |
| Destructor. | |
| const String & | getFormatName () const noexcept |
| Returns a description of what type of format this is. | |
| virtual bool | write (const int **samplesToWrite, int numSamples)=0 |
| Writes a set of samples to the audio stream. | |
| virtual bool | flush () |
| Some formats may support a flush operation that makes sure the file is in a valid state before carrying on. | |
| bool | writeFromAudioReader (AudioFormatReader &reader, int64 startSample, int64 numSamplesToRead) |
| Reads a section of samples from an AudioFormatReader, and writes these to the output. | |
| bool | writeFromAudioSource (AudioSource &source, int numSamplesToRead, int samplesPerBlock=2048) |
| Reads some samples from an AudioSource, and writes these to the output. | |
| bool | writeFromAudioSampleBuffer (const AudioBuffer< float > &source, int startSample, int numSamples) |
| Writes some samples from an AudioBuffer. | |
| bool | writeFromFloatArrays (const float *const *channels, int numChannels, int numSamples) |
| Writes some samples from a set of float data channels. | |
| double | getSampleRate () const noexcept |
| Returns the sample rate being used. | |
| int | getNumChannels () const noexcept |
| Returns the number of channels being written. | |
| int | getBitsPerSample () const noexcept |
| Returns the bit-depth of the data being written. | |
| bool | isFloatingPoint () const noexcept |
| Returns true if it's a floating-point format, false if it's fixed-point. | |
Protected Member Functions | |
| AudioFormatWriter (OutputStream *destStream, const String &formatName, double sampleRate, unsigned int numberOfChannels, unsigned int bitsPerSample) | |
| Creates an AudioFormatWriter object. | |
| AudioFormatWriter (OutputStream *destStream, const String &formatName, double sampleRate, const AudioChannelSet &audioChannelLayout, unsigned int bitsPerSample) | |
| Creates an AudioFormatWriter object. | |
Protected Attributes | |
| double | sampleRate |
| The sample rate of the stream. | |
| unsigned int | numChannels |
| The number of channels being written to the stream. | |
| unsigned int | bitsPerSample |
| The bit depth of the file. | |
| bool | usesFloatingPointData |
| True if it's a floating-point format, false if it's fixed-point. | |
| AudioChannelSet | channelLayout |
| The audio channel layout that the writer should use. | |
| OutputStream * | output |
| The output stream for use by subclasses. | |
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protected |
Creates an AudioFormatWriter object.
| destStream | the stream to write to - this will be deleted by this object when it is no longer needed |
| formatName | the description that will be returned by the getFormatName() method |
| sampleRate | the sample rate to use - the base class just stores this value, it doesn't do anything with it |
| numberOfChannels | the number of channels to write - the base class just stores this value, it doesn't do anything with it |
| bitsPerSample | the bit depth of the stream - the base class just stores this value, it doesn't do anything with it |
References bitsPerSample, and sampleRate.
Referenced by ThreadedWriter, and juce::AudioFormatWriter::ThreadedWriter::ThreadedWriter().
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protected |
Creates an AudioFormatWriter object.
| destStream | the stream to write to - this will be deleted by this object when it is no longer needed |
| formatName | the description that will be returned by the getFormatName() method |
| sampleRate | the sample rate to use - the base class just stores this value, it doesn't do anything with it |
| audioChannelLayout | the channel layout to use for the writer - the base class just stores this value, it doesn't do anything with it |
| bitsPerSample | the bit depth of the stream - the base class just stores this value, it doesn't do anything with it |
References bitsPerSample, and sampleRate.
|
virtual |
Destructor.
|
noexcept |
Returns a description of what type of format this is.
E.g. "AIFF file"
|
pure virtual |
Writes a set of samples to the audio stream.
Note that if you're trying to write the contents of an AudioBuffer, you can use writeFromAudioSampleBuffer().
| samplesToWrite | an array of arrays containing the sample data for each channel to write. This is a zero-terminated array of arrays, and can contain a different number of channels than the actual stream uses, and the writer should do its best to cope with this. If the format is fixed-point, each channel will be formatted as an array of signed integers using the full 32-bit range -0x80000000 to 0x7fffffff, regardless of the source's bit-depth. If it is a floating-point format, you should treat the arrays as arrays of floats, and just cast it to an (int**) to pass it into the method. |
| numSamples | the number of samples to write |
|
virtual |
Some formats may support a flush operation that makes sure the file is in a valid state before carrying on.
If supported, this means that by calling flush periodically when writing data to a large file, then it should still be left in a readable state if your program crashes. It goes without saying that this method must be called from the same thread that's calling write()! If the format supports flushing and the operation succeeds, this returns true.
| bool juce::AudioFormatWriter::writeFromAudioReader | ( | AudioFormatReader & | reader, |
| int64 | startSample, | ||
| int64 | numSamplesToRead ) |
Reads a section of samples from an AudioFormatReader, and writes these to the output.
This will take care of any floating-point conversion that's required to convert between the two formats. It won't deal with sample-rate conversion, though.
If numSamplesToRead < 0, it will write the entire length of the reader.
| bool juce::AudioFormatWriter::writeFromAudioSource | ( | AudioSource & | source, |
| int | numSamplesToRead, | ||
| int | samplesPerBlock = 2048 ) |
Reads some samples from an AudioSource, and writes these to the output.
The source must already have been initialised with the AudioSource::prepareToPlay() method
| source | the source to read from |
| numSamplesToRead | total number of samples to read and write |
| samplesPerBlock | the maximum number of samples to fetch from the source |
| bool juce::AudioFormatWriter::writeFromAudioSampleBuffer | ( | const AudioBuffer< float > & | source, |
| int | startSample, | ||
| int | numSamples ) |
Writes some samples from an AudioBuffer.
| bool juce::AudioFormatWriter::writeFromFloatArrays | ( | const float *const * | channels, |
| int | numChannels, | ||
| int | numSamples ) |
Writes some samples from a set of float data channels.
References numChannels.
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noexcept |
Returns the sample rate being used.
References sampleRate.
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noexcept |
Returns the number of channels being written.
References numChannels.
|
noexcept |
Returns the bit-depth of the data being written.
References bitsPerSample.
|
noexcept |
Returns true if it's a floating-point format, false if it's fixed-point.
References usesFloatingPointData.
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protected |
The sample rate of the stream.
Referenced by AudioFormatWriter(), AudioFormatWriter(), getSampleRate(), and juce::AudioFormatWriter::ThreadedWriter::IncomingDataReceiver::reset().
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protected |
The number of channels being written to the stream.
Referenced by getNumChannels(), juce::AudioFormatWriter::ThreadedWriter::IncomingDataReceiver::reset(), and writeFromFloatArrays().
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protected |
The bit depth of the file.
Referenced by AudioFormatWriter(), AudioFormatWriter(), and getBitsPerSample().
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protected |
True if it's a floating-point format, false if it's fixed-point.
Referenced by isFloatingPoint().
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protected |
The audio channel layout that the writer should use.
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protected |
The output stream for use by subclasses.
