Overview

Periodic WAV playback supporting pitch shifting

Discussion

This module outputs wave data in loop mode. User has to specify the file name as an argument. Along with the above parameters, the playback functionality can be enabled from the control input pin, 1 - Enable and 0 - Disable.

The module supports multichannel such that, if the wave file has more channels than provided to the module argument then only channels up to output pin channels will be used. If the wave file has less channels than output pin channels, then the remaining output channels will be muted.

Type Definition

typedef struct _ModuleWaveLoopPlayerRAMFract32
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32 smoothingTime;                          // Time constant of the pitch smoothing process
    INT32 smoothingFactor;                        // Update rate for smoothing coeffs (per block)
    INT32 startDelay;                             // Starting delay value in samples
    INT32 enable;                                 // En/Disable playback. Resets sample position to startDelay value upon stop
    FLOAT32 normRate;                             // Rate of data used to compute the ratio for normalized players
    FLOAT32 maxRate;                              // Highest allowed rate of playback that can be specified
    INT32 NCOFracBits;                            // Number of least-significant bits for the *fractional* part of the NCO word (word size: 32)
    INT32 waveLength;                             // Number of samples in currently loaded file
    INT32 fIndex;                                 // Current index in the wave file
    FLOAT32 currentFStep;                         // Current (smoothed) rate at which audio is read from the input buffer
    INT32 waveSR;                                 // Actual sample rate of the wave file.
    INT32 waveNumChannels;                        // Number of channels in the wave file.
    FLOAT32 scaleFactor;                          // Scale factor for playback rate
    FLOAT32 smoothingCoeff;                       // Smoothing (pitch) coefficient
    INT32 NCOIntBits;                             // Number of most-significant bits for the *integer* part of the NCO word (word size: 32). By default: 20 bits
    FLOAT32 formatF;                              // Integer value of left-shift by NCOFracBits. Determines the precision of the linear interpolation.
    FLOAT32 formatI;                              // Integer value of left-shift by NCOIntBits. Determines the maximum playback rate and the maximum size of a wave file in samples.
    UINT32 pinID;                                 // Specifies which control pins are available.
    INT32* waveBuffer;                            // Data transferred from PC to target DSP via this buffer.
} ModuleWaveLoopPlayerRAMFract32Class;

Variables

Properties

Name	Type	Usage	isHidden	Default value	Range	Units
smoothingTime	int	parameter	0	10	0:1000	msec
smoothingFactor	int	parameter	0	4	1:512
startDelay	int	parameter	0	0	Unrestricted
enable	int	state	0	1	0:1
normRate	float	const	0	1	Unrestricted
maxRate	float	const	0	2	Unrestricted
NCOFracBits	int	const	0	12	Unrestricted
waveLength	int	derived	0	8976	Unrestricted
fIndex	int	state	0	0	Unrestricted
currentFStep	float	state	0	1	Unrestricted
waveSR	int	derived	1	48000	Unrestricted
waveNumChannels	int	derived	1	1	Unrestricted
scaleFactor	float	derived	1	1	Unrestricted
smoothingCoeff	float	derived	1	0.1248	Unrestricted
NCOIntBits	int	derived	1	20	Unrestricted
formatF	float	derived	1	4096	Unrestricted
formatI	float	derived	1	524300	Unrestricted
pinID	uint	const	1	3	Unrestricted
waveBuffer	int*	parameter	0	[4490 x 1]	Unrestricted

Pins

Input Pins

Name: enable

Description: Flag to enable playback

Data type: int

Channel range: 1

Block size range: 1

Sample rate range: Unrestricted

Complex support: Real

Name: fRatio

Description: Specifies sample rate ratio

Data type: float

Channel range: 1

Block size range: 1

Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: audio

Description: output data

Data type: fract32

Name: isPlaying

Description: playing state