Overview

Delays signals by a multiple of the blockSize

Discussion

A block delay module, where the delay is specified as an integer number of blocks. The delay is implemented such that delays as short as 0 blocks can be realized. The module has one multichannel input and one multichannel output. The module can operate on multiple channels and applies the same delay to each channel.

At construction time, specify the maximum delay (maxDelay) of the module. The variable, maxDelay determines the size of the internal state buffer. The size of the internal state buffer equals (maxBlockDelay+1)*blockSize*numChannels. In addition, the instantaneous delay is specified through the interface variable, currentBlockDelay. currentBlockDelay is in the range of [0 maxBlockDelay] and can be changed at run-time. Note that the module is not smoothly updating and you may get audible clicks when adjusting the currentBlockDelay at run-time.

Type Definition

typedef struct _ModuleBlockDelayV2
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32 maxBlockDelay;                          // Maximum delay that can be realized, in blocks. The size of the delay buffer, (maxDelay+1)*blockSize*numChannels.
    INT32 currentBlockDelay;                      // Current block delay.
    INT32 stateIndex;                             // Index of the oldest state variable in the array of state variables.
    INT32 stateHeap;                              // Heap in which to allocate memory.
    FLOAT32* state;                               // State variable array.
} ModuleBlockDelayV2Class;

Variables

Properties

Name	Type	Usage	isHidden	Default value	Range	Units
maxBlockDelay	int	const	0	10	1:1000	blocks
currentBlockDelay	int	parameter	0	0	0:1:10	blocks
stateIndex	int	state	1	0	Unrestricted
stateHeap	int	const	1	2	Unrestricted
state	float*	state	1	[1 x 352]	Unrestricted

Pins

Input Pins

Name: in

Description: audio input

Data type: {float, int, fract32}

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real and Complex

Output Pins

Name: out

Description: audio output

Data type: {float, int, fract32}

MATLAB Usage

File Name: block_delay_v2_module.m

 M=block_delay_v2_module(NAME, MAXBLOCKDELAY, MEMHEAP)
 Creates a block delay module for use in the Audio Weaver environment. The
 module delays the input by a multiple of the block size.  
 
 Arguments:
    NAME - name of the module.
    MAXBLOCKDELAY - maximum delay, in blocks.
    MEMHEAP - specifies the memory heap to use to allocate the main
         state buffer. This is a string and follows the memory allocation
         enumeration in Framework.h. Allowable values are:
            'AWE_HEAP_FAST' - always use internal DM memory.
            'AWE_HEAP_FASTB' - always use internal PM memory.
            'AWE_HEAP_SLOW' - always use external memory (the default).
            'AWE_HEAP_FAST2SLOW' - use internal memory. If this fails
               then use external memory.