Wave Loop Player Flash Fract32

Overview

Periodic WAV playback supporting pitch shifting

Discussion

This module outputs wave data in fract32 format in loop mode. It extracts wave data based on "fileName" argument from an AWE Flash File System container on the target Flash device. User has to specify the file name as an argument and can also change file name directly in the "fileName" array as 32-bit packed data during run time. The WAV files itself must be in 16 bit PCM format.

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 will be used. If the wave file has less channels than output pin channels, then the remaining output channels will be muted.

On windows (Native PC) or Linux platforms, file operations are used and make sure the file path exists in the Audio Weaver file search path. If not, please update the file search path from File->Set File Search Path in the Designer. Maximum absolute file path should not be more than 512 characters.

Optional argument MUTMOD can be used to mute output before changing file in run time.

Optional argument UNMUTEMOD can be used to un-mute output after file is processed in run time.

If any errors occurs in the module, it is captured in the parameter .errorCodes. Please check in Errors.h for the meaning of error code returned.

During the runtime, module may return positive error codes with the following meaning:

1 - indicates pitch ratio is more than max supported.     2 - indicates wave file has more than the max supported number of channels.

Module Pack

awe-mod-dspc-snd

ClassID

classID = 41833

Type Definition

typedef struct _ModuleWaveLoopPlayerFlashFract32
{
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 maxWaveChannels;                        // Maximum number of channels a wave file can have
INT32 waveLength;                             // Number of samples in currently loaded file
INT32 fIndex;                                 // Current index in the wave file
FLOAT32 fIndexFract;                          // Current fract index in the wave file
INT32 errorCode;                              // Captures errors that could arise in the module C code. Appears on the inspector 
INT32 isReady;                                // Boolean that indicates the module is not ready to output data
INT32 waitForMuteDone;                        // Internal flag to check if the smooth mute is done
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.
INT32 waveBit;                                // Wave data sample bit resolution.
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.
INT32 decFactor;                              // Internal derived variable to hold decimated smoothing blocks
INT32 waveBuffer;                             // State variable holds the start ofset of the wave file in flash file system.
UINT32 pinID;                                 // Specifies which control pins are available.
INT32* fileName;                              // Name of wave file to playback
INT32* fileNamePrev;                          // Name of wave file to playback
void * muteModPtr;                            // Internal pointer to mute module to mute before reconfiguration
void * unMuteModPtr;                          // Internal pointer to mute module to unmute after reconfiguration
void * localWaveBuffer;                       // Internal pointer used only on Windows or Linux, which holds entire wave data
void * pOwnerPtr;                             // Pointer to hold owner AWEInstance pointer
} ModuleWaveLoopPlayerFlashFract32Class;

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
maxWaveChannels	int	const	0	10	Unrestricted
waveLength	int	derived	0	0	Unrestricted
fIndex	int	state	0	0	Unrestricted
fIndexFract	float	state	0	0	Unrestricted
errorCode	int	state	0	0	Unrestricted
isReady	int	state	0	0	Unrestricted
waitForMuteDone	int	state	0	0	Unrestricted
currentFStep	float	state	0	1	Unrestricted
waveSR	int	derived	1	0	Unrestricted
waveNumChannels	int	derived	1	0	Unrestricted
waveBit	int	derived	1	0	Unrestricted
scaleFactor	float	derived	1	1	Unrestricted
smoothingCoeff	float	derived	1	0	Unrestricted
NCOIntBits	int	derived	1	20	Unrestricted
formatF	float	derived	1	0	Unrestricted
formatI	float	derived	1	0	Unrestricted
decFactor	int	derived	1	1	Unrestricted
waveBuffer	int	state	1	0	Unrestricted
pinID	uint	const	1	3	Unrestricted
fileName	int*	parameter	1	[14 x 1]	Unrestricted
fileNamePrev	int*	state	1	[14 x 1]	Unrestricted
muteModPtr	void *	state	1	0	Unrestricted
unMuteModPtr	void *	state	1	0	Unrestricted
localWaveBuffer	void *	state	1		Unrestricted
pOwnerPtr	void *	state	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
Data Type	int

Scratch Pins


Channel Count	10
Block size	259
Sample rate	48000

Matlab Usage

File Name: wave_loop_player_flash_fract32_module.m