Functions for interacting with DSP audio channels. More...

Functions
Basic channel operation
void	ndspChnReset (int id)
	Resets a channel. More...

void	ndspChnInitParams (int id)
	Initializes the parameters of a channel. More...

bool	ndspChnIsPlaying (int id)
	Checks whether a channel is currently playing. More...

u32	ndspChnGetSamplePos (int id)
	Gets the current sample position of a channel. More...

u16	ndspChnGetWaveBufSeq (int id)
	Gets the sequence ID of the wave buffer that is currently playing in a channel. More...

bool	ndspChnIsPaused (int id)
	Checks whether a channel is currently paused. More...

void	ndspChnSetPaused (int id, bool paused)
	Sets the pause status of a channel. More...

Configuration
void	ndspChnSetFormat (int id, u16 format)
	Sets the format of a channel. More...

u16	ndspChnGetFormat (int id)
	Gets the format of a channel. More...

void	ndspChnSetInterp (int id, ndspInterpType type)
	Sets the interpolation type of a channel. More...

ndspInterpType	ndspChnGetInterp (int id)
	Gets the interpolation type of a channel. More...

void	ndspChnSetRate (int id, float rate)
	Sets the sample rate of a channel. More...

float	ndspChnGetRate (int id)
	Gets the sample rate of a channel. More...

void	ndspChnSetMix (int id, float mix[12])
	Sets the mix parameters (volumes) of a channel. More...

void	ndspChnGetMix (int id, float mix[12])
	Gets the mix parameters (volumes) of a channel. More...

void	ndspChnSetAdpcmCoefs (int id, u16 coefs[16])
	Sets the DSPADPCM coefficients of a channel. More...

Wave buffers
void	ndspChnWaveBufClear (int id)
	Clears the wave buffer queue of a channel and stops playback. More...

void	ndspChnWaveBufAdd (int id, ndspWaveBuf *buf)
	Adds a wave buffer to the wave buffer queue of a channel. More...

IIR filters
void	ndspChnIirMonoSetEnable (int id, bool enable)
	Configures whether the IIR monopole filter of a channel is enabled. More...

bool	ndspChnIirMonoSetParamsCustomFilter (int id, float a0, float a1, float b0)
	Manually sets up the parameters on monopole filter. More...

bool	ndspChnIirMonoSetParamsLowPassFilter (int id, float f0)
	Sets the monopole to be a low pass filter. More...

bool	ndspChnIirMonoSetParamsHighPassFilter (int id, float f0)
	Sets the monopole to be a high pass filter. More...

void	ndspChnIirBiquadSetEnable (int id, bool enable)
	Configures whether the IIR biquad filter of a channel is enabled. More...

bool	ndspChnIirBiquadSetParamsCustomFilter (int id, float a0, float a1, float a2, float b0, float b1, float b2)
	Manually sets up the parameters of the biquad filter. More...

bool	ndspChnIirBiquadSetParamsLowPassFilter (int id, float f0, float Q)
	Sets the biquad to be a low pass filter. More...

bool	ndspChnIirBiquadSetParamsHighPassFilter (int id, float f0, float Q)
	Sets the biquad to be a high pass filter. More...

bool	ndspChnIirBiquadSetParamsBandPassFilter (int id, float f0, float Q)
	Sets the biquad to be a band pass filter. More...

bool	ndspChnIirBiquadSetParamsNotchFilter (int id, float f0, float Q)
	Sets the biquad to be a notch filter. More...

bool	ndspChnIirBiquadSetParamsPeakingEqualizer (int id, float f0, float Q, float gain)
	Sets the biquad to be a peaking equalizer. More...

Data types
Supported sample encodings.
#define	NDSP_CHANNELS(n) ((u32)(n) & 3)
	Specifies the number of channels used in a sample.

#define	NDSP_ENCODING(n) (((u32)(n) & 3) << 2)
	Specifies the encoding used in a sample.

enum	{ NDSP_ENCODING_PCM8 = 0 , NDSP_ENCODING_PCM16 , NDSP_ENCODING_ADPCM }

enum	{ NDSP_FORMAT_MONO_PCM8 = NDSP_CHANNELS(1) \| NDSP_ENCODING(NDSP_ENCODING_PCM8) , NDSP_FORMAT_MONO_PCM16 = NDSP_CHANNELS(1) \| NDSP_ENCODING(NDSP_ENCODING_PCM16) , NDSP_FORMAT_MONO_ADPCM = NDSP_CHANNELS(1) \| NDSP_ENCODING(NDSP_ENCODING_ADPCM) , NDSP_FORMAT_STEREO_PCM8 = NDSP_CHANNELS(2) \| NDSP_ENCODING(NDSP_ENCODING_PCM8) , NDSP_FORMAT_STEREO_PCM16 = NDSP_CHANNELS(2) \| NDSP_ENCODING(NDSP_ENCODING_PCM16) , NDSP_FORMAT_PCM8 = NDSP_FORMAT_MONO_PCM8 , NDSP_FORMAT_PCM16 = NDSP_FORMAT_MONO_PCM16 , NDSP_FORMAT_ADPCM = NDSP_FORMAT_MONO_ADPCM , NDSP_FRONT_BYPASS = BIT(4) , NDSP_3D_SURROUND_PREPROCESSED = BIT(6) }
	Channel format flags for use with ndspChnSetFormat. More...

enum	ndspInterpType { NDSP_INTERP_POLYPHASE = 0 , NDSP_INTERP_LINEAR = 1 , NDSP_INTERP_NONE = 2 }
	Interpolation types. More...

Detailed Description

Functions for interacting with DSP audio channels.

Enumeration Type Documentation

◆ anonymous enum

anonymous enum

Enumerator
NDSP_ENCODING_PCM8	PCM8.
NDSP_ENCODING_PCM16	PCM16.
NDSP_ENCODING_ADPCM	DSPADPCM (GameCube format)

◆ anonymous enum

anonymous enum

Channel format flags for use with ndspChnSetFormat.

Enumerator
NDSP_FORMAT_MONO_PCM8	Buffer contains Mono PCM8.
NDSP_FORMAT_MONO_PCM16	Buffer contains Mono PCM16.
NDSP_FORMAT_MONO_ADPCM	Buffer contains Mono ADPCM.
NDSP_FORMAT_STEREO_PCM8	Buffer contains Stereo PCM8.
NDSP_FORMAT_STEREO_PCM16	Buffer contains Stereo PCM16.
NDSP_FORMAT_PCM8	(Alias) Buffer contains Mono PCM8.
NDSP_FORMAT_PCM16	(Alias) Buffer contains Mono PCM16.
NDSP_FORMAT_ADPCM	(Alias) Buffer contains Mono ADPCM.
NDSP_FRONT_BYPASS	Front bypass.
NDSP_3D_SURROUND_PREPROCESSED	(?) Unknown, under research

◆ ndspInterpType

enum ndspInterpType

Interpolation types.

Enumerator
NDSP_INTERP_POLYPHASE	Polyphase interpolation.
NDSP_INTERP_LINEAR	Linear interpolation.
NDSP_INTERP_NONE	No interpolation.

Function Documentation

◆ ndspChnGetFormat()

u16 ndspChnGetFormat ( int id )

Gets the format of a channel.

Parameters

id	ID of the channel (0..23).

Returns: The format of the channel.

◆ ndspChnGetInterp()

ndspInterpType ndspChnGetInterp ( int id )

Gets the interpolation type of a channel.

Parameters

id	ID of the channel (0..23).

Returns: The interpolation type of the channel.

◆ ndspChnGetMix()

void ndspChnGetMix	(	int	id,
		float	mix[12]
	)

Gets the mix parameters (volumes) of a channel.

Parameters

id	ID of the channel (0..23)
mix	Mix parameters to write out to. See ndspChnSetMix.

◆ ndspChnGetRate()

float ndspChnGetRate ( int id )

Gets the sample rate of a channel.

Parameters

id	ID of the channel (0..23).

Returns: The sample rate of the channel.

◆ ndspChnGetSamplePos()

u32 ndspChnGetSamplePos ( int id )

Gets the current sample position of a channel.

Parameters

id	ID of the channel (0..23).

Returns: The channel's sample position.

◆ ndspChnGetWaveBufSeq()

u16 ndspChnGetWaveBufSeq ( int id )

Gets the sequence ID of the wave buffer that is currently playing in a channel.

Parameters

id	ID of the channel (0..23).

Returns: The sequence ID of the wave buffer.

◆ ndspChnIirBiquadSetEnable()

void ndspChnIirBiquadSetEnable	(	int	id,
		bool	enable
	)

Configures whether the IIR biquad filter of a channel is enabled.

Parameters

id	ID of the channel (0..23).
enable	Whether to enable the IIR biquad filter.

Examples: audio/filters/source/main.c.

◆ ndspChnIirBiquadSetParamsBandPassFilter()

bool ndspChnIirBiquadSetParamsBandPassFilter	(	int	id,
		float	f0,
		float	Q
	)

Sets the biquad to be a band pass filter.

Parameters

id	ID of the channel (0..23).
f0	Mid-frequency.
Q	"Quality factor", typically should be sqrt(2)/2 (i.e. 0.7071).

Examples: audio/filters/source/main.c.

◆ ndspChnIirBiquadSetParamsCustomFilter()

bool ndspChnIirBiquadSetParamsCustomFilter	(	int	id,
		float	a0,
		float	a1,
		float	a2,
		float	b0,
		float	b1,
		float	b2
	)

Manually sets up the parameters of the biquad filter.

Parameters

id	ID of the channel (0..23).

◆ ndspChnIirBiquadSetParamsHighPassFilter()

bool ndspChnIirBiquadSetParamsHighPassFilter	(	int	id,
		float	f0,
		float	Q
	)

Sets the biquad to be a high pass filter.

Parameters

id	ID of the channel (0..23).
f0	High pass cut-off frequency.
Q	"Quality factor", typically should be sqrt(2)/2 (i.e. 0.7071).

Examples: audio/filters/source/main.c.

◆ ndspChnIirBiquadSetParamsLowPassFilter()

bool ndspChnIirBiquadSetParamsLowPassFilter	(	int	id,
		float	f0,
		float	Q
	)

Sets the biquad to be a low pass filter.

Parameters

id	ID of the channel (0..23).
f0	Low pass cut-off frequency.
Q	"Quality factor", typically should be sqrt(2)/2 (i.e. 0.7071).

Examples: audio/filters/source/main.c.

◆ ndspChnIirBiquadSetParamsNotchFilter()

bool ndspChnIirBiquadSetParamsNotchFilter	(	int	id,
		float	f0,
		float	Q
	)

Sets the biquad to be a notch filter.

Parameters

id	ID of the channel (0..23).
f0	Notch frequency.
Q	"Quality factor", typically should be sqrt(2)/2 (i.e. 0.7071).

Examples: audio/filters/source/main.c.

◆ ndspChnIirBiquadSetParamsPeakingEqualizer()

bool ndspChnIirBiquadSetParamsPeakingEqualizer	(	int	id,
		float	f0,
		float	Q,
		float	gain
	)

Sets the biquad to be a peaking equalizer.

Parameters

id	ID of the channel (0..23).
f0	Central frequency.
Q	"Quality factor", typically should be sqrt(2)/2 (i.e. 0.7071).
gain	Amount of gain (raw value = 10 ^ dB/40)

Examples: audio/filters/source/main.c.

◆ ndspChnIirMonoSetEnable()

void ndspChnIirMonoSetEnable	(	int	id,
		bool	enable
	)

Configures whether the IIR monopole filter of a channel is enabled.

Parameters

id	ID of the channel (0..23).
enable	Whether to enable the IIR monopole filter.

◆ ndspChnIirMonoSetParamsCustomFilter()

bool ndspChnIirMonoSetParamsCustomFilter	(	int	id,
		float	a0,
		float	a1,
		float	b0
	)

Manually sets up the parameters on monopole filter.

Parameters

id	ID of the channel (0..23).
enable	Whether to enable the IIR monopole filter.

◆ ndspChnIirMonoSetParamsHighPassFilter()

bool ndspChnIirMonoSetParamsHighPassFilter	(	int	id,
		float	f0
	)

Sets the monopole to be a high pass filter.

(Note: This is a lower-quality filter than the biquad one.)

Parameters

id	ID of the channel (0..23).
f0	High pass cut-off frequency.

◆ ndspChnIirMonoSetParamsLowPassFilter()

bool ndspChnIirMonoSetParamsLowPassFilter	(	int	id,
		float	f0
	)

Sets the monopole to be a low pass filter.

(Note: This is a lower-quality filter than the biquad one.)

Parameters

id	ID of the channel (0..23).
f0	Low pass cut-off frequency.

◆ ndspChnInitParams()

void ndspChnInitParams ( int id )

Initializes the parameters of a channel.

Parameters

id	ID of the channel (0..23).

◆ ndspChnIsPaused()

bool ndspChnIsPaused ( int id )

Checks whether a channel is currently paused.

Parameters

id	ID of the channel (0..23).

Returns: Whether the channel is currently paused.

◆ ndspChnIsPlaying()

bool ndspChnIsPlaying ( int id )

Checks whether a channel is currently playing.

Parameters

id	ID of the channel (0..23).

Returns: Whether the channel is currently playing.

◆ ndspChnReset()

void ndspChnReset ( int id )

Resets a channel.

Parameters

id	ID of the channel (0..23).

◆ ndspChnSetAdpcmCoefs()

void ndspChnSetAdpcmCoefs	(	int	id,
		u16	coefs[16]
	)

Sets the DSPADPCM coefficients of a channel.

Parameters

id	ID of the channel (0..23).
coefs	DSPADPCM coefficients to use.

◆ ndspChnSetFormat()

void ndspChnSetFormat	(	int	id,
		u16	format
	)

Sets the format of a channel.

Parameters

id	ID of the channel (0..23).
format	Format to use.

Examples: audio/filters/source/main.c, and audio/streaming/source/main.c.

◆ ndspChnSetInterp()

void ndspChnSetInterp	(	int	id,
		ndspInterpType	type
	)

Sets the interpolation type of a channel.

Parameters

id	ID of the channel (0..23).
type	Interpolation type to use.

Examples: audio/filters/source/main.c, and audio/streaming/source/main.c.

◆ ndspChnSetMix()

void ndspChnSetMix	(	int	id,
		float	mix[12]
	)

Sets the mix parameters (volumes) of a channel.

Parameters

id	ID of the channel (0..23).
mix	Mix parameters to use. Working hypothesis: 0: Front left volume. 1: Front right volume. 2: Back left volume: 3: Back right volume: 4..7: Same as 0..3, but for auxiliary output 0. 8..11: Same as 0..3, but for auxiliary output 1.

Examples: audio/filters/source/main.c, and audio/streaming/source/main.c.

◆ ndspChnSetPaused()

void ndspChnSetPaused	(	int	id,
		bool	paused
	)

Sets the pause status of a channel.

Parameters

id	ID of the channel (0..23).
paused	Whether the channel is to be paused (true) or unpaused (false).

◆ ndspChnSetRate()

void ndspChnSetRate	(	int	id,
		float	rate
	)

Sets the sample rate of a channel.

Parameters

id	ID of the channel (0..23).
rate	Sample rate to use.

Examples: audio/filters/source/main.c, and audio/streaming/source/main.c.

◆ ndspChnWaveBufAdd()

void ndspChnWaveBufAdd	(	int	id,
		ndspWaveBuf *	buf
	)

Adds a wave buffer to the wave buffer queue of a channel.

Remarks: If the channel's wave buffer queue was empty before the use of this function, playback is started.

Parameters

id	ID of the channel (0..23).
buf	Wave buffer to add.

Examples: audio/filters/source/main.c, and audio/streaming/source/main.c.

◆ ndspChnWaveBufClear()

void ndspChnWaveBufClear ( int id )

Clears the wave buffer queue of a channel and stops playback.

Parameters

id	ID of the channel (0..23).

Functions

Data types

Detailed Description

Enumeration Type Documentation

◆ anonymous enum

◆ anonymous enum

◆ ndspInterpType

Function Documentation

◆ ndspChnGetFormat()

◆ ndspChnGetInterp()

◆ ndspChnGetMix()

◆ ndspChnGetRate()

◆ ndspChnGetSamplePos()

◆ ndspChnGetWaveBufSeq()

◆ ndspChnIirBiquadSetEnable()

◆ ndspChnIirBiquadSetParamsBandPassFilter()

◆ ndspChnIirBiquadSetParamsCustomFilter()

◆ ndspChnIirBiquadSetParamsHighPassFilter()

◆ ndspChnIirBiquadSetParamsLowPassFilter()

◆ ndspChnIirBiquadSetParamsNotchFilter()

◆ ndspChnIirBiquadSetParamsPeakingEqualizer()

◆ ndspChnIirMonoSetEnable()

◆ ndspChnIirMonoSetParamsCustomFilter()

◆ ndspChnIirMonoSetParamsHighPassFilter()

◆ ndspChnIirMonoSetParamsLowPassFilter()

◆ ndspChnInitParams()

◆ ndspChnIsPaused()

◆ ndspChnIsPlaying()

◆ ndspChnReset()

◆ ndspChnSetAdpcmCoefs()

◆ ndspChnSetFormat()

◆ ndspChnSetInterp()

◆ ndspChnSetMix()

◆ ndspChnSetPaused()

◆ ndspChnSetRate()

◆ ndspChnWaveBufAdd()

◆ ndspChnWaveBufClear()