Converting Streams

Stream classes which change the input or output. More...

Classes
class	AudioEffectStream
	EffectsStream supporting variable bits_per_sample. This class is only available when __cplusplus >= 201703L. Otherwise AudioEffectStream results in using AudioEffectStream = AudioEffectStreamT<effect_t>;. More...
class	AudioEffectStreamT< T >
	EffectsStreamT: the template class describes an input or output stream to which one or multiple effects are applied. Each channel is processed by its own independent clone of the effect chain (created via AudioEffect::clone()), so e.g. a stereo signal keeps its channel separation and effects that carry internal state (Delay's ring buffer, ADSRGain/Tremolo's envelope or oscillator phase, etc.) don't get confused by interleaved samples from different channels. addEffect() adds to a shared template chain that is cloned into every channel on begin() (and immediately cloned into all already-active channels if called afterwards); use addEffect(channel, effect) to register an effect directly on just one channel instead. Note that size()/operator[]/findEffect() operate on the template chain, not on the per-channel clones: mutating a pointer obtained from them after begin() has already cloned it does not retroactively change already-cloned per-channel copies. Currently only int16_t values are supported, so I recommend to use the AudioEffectStream class which is defined as using AudioEffectStream = AudioEffectStreamT<effect_t>;. More...
class	ChannelFormatConverterStream
	Channel converter which does not use a template. More...
class	ChannelFormatConverterStreamT< T >
	Converter for reducing or increasing the number of Channels. More...
class	ChannelSplitOutput
	Simple functionality to extract mono streams from a multichannel (e.g. stereo) signal. More...
class	ChannelsSelectOutput
	Flexible functionality to extract one or more channels from a multichannel signal. Warning: the destinatios added with addOutput are not automatically notified about audio changes. More...
class	ConverterStream< T >
	Both the data of the read or write operations will be converted with the help of the indicated converter. More...
class	EncodedAudioOutput
	A more natural Print class to process encoded data (aac, wav, mp3...). Just define the output and the decoder and write the encoded data. More...
class	EncodedAudioStream
	A more natural Stream class to process encoded data (aac, wav, mp3...) which also supports the decoding by calling readBytes(). More...
class	FadeStream
	Stream which can be used to manage fade in and fade out. Before you read or write data you need to call setAudioInfo() to provide the bits_per_sample and channels. More...
class	FFTEffect
	Abstract base class for effects that operate on audio in the frequency domain: incoming samples are transformed with a forward FFT, the resulting bins are modified by the effect() method that a subclass implements, and the modified spectrum is transformed back with an inverse FFT (overlap-add) and streamed to the output. More...
struct	FFTEffectConfig
	Common configuration for FFT effects. More...
class	FFTEqualizer
	Graphic Equalizer implemented as an FFT effect: boosts or cuts logarithmically spaced frequency bands (20Hz .. Nyquist) by scaling the magnitude of the bins that fall into each band while leaving their phase untouched. Since this operates directly on the frequency-domain bins rather than an FIR/IIR approximation, band edges are exact and there is no filter ripple. More...
struct	FFTEqualizerConfig
	Equalizer FFT Effect Configuration. More...
class	FFTNop
	Apply FFT and IFFT w/o any changes to the frequency domain. More...
class	FFTPitchShift
	Apply Pitch Shift FFT Effect on frequency domain data: we just move the bins up or down. More...
struct	FFTPitchShiftConfig
	Pitch Shift FFT Effect Configuration. More...
class	FFTRobotize
	Apply Robotize FFT Effect on frequency domain data. See https://learn.bela.io/tutorials/c-plus-plus-for-real-time-audio-programming/phase-vocoder-part-3/. More...
class	FFTWhisper
	Apply Whisper FFT Effect on frequency domain data: keep the magnitude of each bin but randomize its phase. See https://learn.bela.io/tutorials/c-plus-plus-for-real-time-audio-programming/phase-vocoder-part-3/. More...
class	FilteredStream< T, TF >
	Stream to which we can apply Filters for each channel. The filter might change the result size! More...
class	FormatConverterStream
	Converter which converts bits_per_sample, channels and the sample_rate. The conversion is supported both on the input and output side. More...
class	InputMerge< T >
	Merges multiple input streams. So if you provide 2 mono channels you get a stereo signal as result with the left channel from channel 0 and the right from channel 1. More...
class	InputMixer< T, SumT >
	MixerStream is mixing the input from Multiple Input Streams. All streams must have the same audo format (sample rate, channels, bits per sample). More...
class	MultiOutput
	Replicates the output to multiple destinations. More...
class	NumberFormatConverterStream
	Converter which converts between bits_per_sample and 16 bits. The templated NumberFormatConverterStreamT class is used based on the information provided by the bits_per_sample in the configuration. More...
class	NumberFormatConverterStreamT< TFrom, TTo >
	A more generic templated Converter which converts from a source type to a target type: You can use e.g. uint8_t, int8_t, int16_t, uint16_t, int24_t, uint32_t, int32_t, FloatAudio.AbstractMetaDat. This is quite handy because unsigned values and floating values are supported and you do not need to resort to use a Codec. More...
class	OutputMixer< T >
	Mixing of multiple audio input streams into a single output stream. More...
class	Pipeline
	We can build a input or an output chain: an input chain starts with setInput(); followed by add() an output chain consinsts of add() and ends with setOutput();. More...
class	PitchShiftOutput< T, BufferT >
	Real-time pitch shifting audio effect. More...
class	ResampleStream
	Dynamic Resampling. We can use a variable factor to speed up or slow down the playback. More...
class	RTTTLOutput< T >
	RTTTL (Ring Tone Text Transfer Language) parser and player stream. More...
class	TimedStream
	AudioStream class that can define a start and (an optional) stop time Usually it is used to wrap an Audio Sink (e.g. I2SStream), but wrapping an Audio Source is supported as well. Only wrap classes which represent PCM data! More...
class	VolumeStream
	Adjust the volume of the related input or output: To work properly the class needs to know the bits per sample and number of channels! AudioChanges are forwareded to the related Print or Stream class. More...

Detailed Description

Stream classes which change the input or output.