Overview

Channel routing without smoothing

Discussion

The router_module.m is an intelligent copier and combines several channels from different wires into a new multichannel wire.  The module can have multiple input pins but only a single output pin.  At instantiation time, you specify the number of input pins and number of output channels.

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The module’s use will become clear through several examples.

Example #1 — Selecting a single channel

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This is wasteful because it requires 3 modules to do what a single router module can do.  Create a Router with 1 input pin and 1 output channel.

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If instead you want to pass the right channel, set channelIndex to 65536*0 + 1 = 1. The string shown on the canvas will update showing you the specified channel ordering:

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Example #2 — Selecting 2 channels

Suppose you have a 5.1 signal with channels ordered:  L, C, R, Ls, Rs, LFE.  If you want to form a new stereo signal with just the L and R channels, use a router with a single input pin and 2 output channels.  Then set the channelIndex values to:

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channelIndex[1] = 65536 * 0 + 4 = 4

Example #3 — Swapping left and right channels

The output channels do now have to be in the same order as the inputs.  For example, suppose you had a stereo signal and you want to swap the order of the left and right channels.  Create the Router module with 1 input pin and 2 output channels.  Then set:

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channelIndex[1] = 65536 * 0 + 0 = 0

Example #4 — Deleting a channel

Suppose you have a 5.1 signal with channels ordered:  L, R, C, LFE, Ls, Rs.  If you want to form a new 5 channel signal that excludes the LFE channel you would use a Router module with 1 input pin and 5 output channels.  Then set the channelIndex array to:

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channelIndex[4] = 65536 * 0 + 5 = 5             // Rs

Example #5 — Inserting a channel

Let’s continue the previous example.  Suppose that you processed the LFE channel separately and now want to combine the 5 channel signal (L, R, C, Ls, Rs) with a separate LFE and form the signal (L, R, C, LFE, Ls, Rs).  You could do this with a Router module.  Configure the Router so that it has 2 input pins and 6 output channels.  The first input pin attaches to the 5 channel signal and the 2^nd output pin attaches to the LFE.  The channelIndex array is then configured as:

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channelIndex[5] = 65536 * 0 + 5 = 5             // Rs

Type Definition

typedef struct _ModuleRouter
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32* channelIndex;                          // Specifies input to output channel routing. Each item in the array corresponds to an output channel and contains two packed values: input pin number in the high 16 bits; input channel number in the low 16 bits.
} ModuleRouterClass;

Variables

Properties

Pins

Input Pins

Name: in1

Description: Input signal

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Complex support: Real and Complex

Output Pins

Name: out

Description: Output signal

Data type: {float, int, fract32}

MATLAB Usage

File Name: router_module.m

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