roc::audio::BuiltinResampler Class Reference

Built-in resampler. More...

#include <builtin_resampler.h>

Inheritance diagram for roc::audio::BuiltinResampler:

Collaboration diagram for roc::audio::BuiltinResampler:

Public Member Functions
	BuiltinResampler (core::IArena &arena, core::BufferFactory< sample_t > &buffer_factory, ResamplerProfile profile, const audio::SampleSpec &in_spec, const audio::SampleSpec &out_spec)
	Initialize. More...
virtual bool	is_valid () const
	Check if object is successfully constructed. More...
virtual bool	set_scaling (size_t input_rate, size_t output_rate, float multiplier)
	Set new resample factor. More...
virtual const core::Slice< sample_t > &	begin_push_input ()
	Get buffer to be filled with input data. More...
virtual void	end_push_input ()
	Commit buffer with input data. More...
virtual size_t	pop_output (sample_t *out_data, size_t out_size)
	Read samples from input frame and fill output frame. More...
virtual float	n_left_to_process () const
	How many samples were pushed but not processed yet. More...
Public Member Functions inherited from roc::audio::IResampler
	IResampler (core::IArena &arena)
	Initialization. More...
virtual	~IResampler ()
	Deinitialization. More...
Public Member Functions inherited from roc::core::RefCounted< IResampler, core::ArenaAllocation >
	RefCounted ()
	Initialize. More...
	RefCounted (const core::ArenaAllocation &policy)
	Initialize. More...
int	getref () const
	Get reference counter. More...
void	incref () const
	Increment reference counter. More...
void	decref () const
	Decrement reference counter. More...

Additional Inherited Members
Protected Member Functions inherited from roc::core::ArenaAllocation
IArena &	arena () const
	Get arena. More...
	ArenaAllocation (IArena &arena)
	Initialize. More...
template<class T >
void	destroy (T &object)
	Destroy object and return memory to arena. More...

Detailed Description

Built-in resampler.

Resamples audio stream with non-integer dynamically changing factor. Implements bandlimited interpolation from this paper: https://ccrma.stanford.edu/~jos/resample/resample.pdf

This backend is quite CPU-hungry, but it maintains requested scaling factor with very high precision.

Definition at line 39 of file builtin_resampler.h.

Constructor & Destructor Documentation

BuiltinResampler()

roc::audio::BuiltinResampler::BuiltinResampler	(	core::IArena &	arena,
		core::BufferFactory< sample_t > &	buffer_factory,
		ResamplerProfile	profile,
		const audio::SampleSpec &	in_spec,
		const audio::SampleSpec &	out_spec
	)

Initialize.

Member Function Documentation

begin_push_input()

virtual const core::Slice<sample_t>& roc::audio::BuiltinResampler::begin_push_input ( )

virtual

Get buffer to be filled with input data.

Implements roc::audio::IResampler.

end_push_input()

virtual void roc::audio::BuiltinResampler::end_push_input ( )

virtual

Commit buffer with input data.

Implements roc::audio::IResampler.

is_valid()

virtual bool roc::audio::BuiltinResampler::is_valid ( ) const

virtual

Check if object is successfully constructed.

Implements roc::audio::IResampler.

n_left_to_process()

virtual float roc::audio::BuiltinResampler::n_left_to_process ( ) const

virtual

How many samples were pushed but not processed yet.

Implements roc::audio::IResampler.

pop_output()

virtual size_t roc::audio::BuiltinResampler::pop_output ( sample_t *  out_data, size_t  out_size  )

virtual

Read samples from input frame and fill output frame.

Implements roc::audio::IResampler.

set_scaling()

virtual bool roc::audio::BuiltinResampler::set_scaling ( size_t  input_rate, size_t  output_rate, float  multiplier  )

virtual

Set new resample factor.

Remarks

Resampling algorithm needs some window of input samples. The length of the window (length of sinc impulse response) is a compromise between SNR and speed. It depends on current resampling factor. So we choose length of input buffers to let it handle maximum length of input. If new scaling factor breaks equation this function returns false.

Implements roc::audio::IResampler.

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

• roc_audio/builtin_resampler.h