This version (13 Sep 2022 11:38) was approved by Angu Sewa.The Previously approved version (19 Mar 2021 17:47) is available.
Table of Contents
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Linear Interpolator
Description
The Linear Interpolator maps an input function to a set of data points that are stored in an index table. If the input function does not align exactly with a table point, the output value will be approximated using a linear interpolant, or a line drawn between the two closest points on the index table. Linear interpolation is a common calculation for a variety of computing applications such as computer graphics. In SigmaStudio, it can be used to make an input-to-output transfer function for audio or control signals without requiring many table points or calculations
The linear interpolation cell performs interpolation of a data set.
The input of the linear interpolation cell must lie between a set minimum and maximum value. The input values between the min and max input values are mapped linearly to an index number between 0 and n, with n representing the maximum index.
For example, if input = min, then index 0 is selected. If input = max, then index n is selected. If the input lies halfway between two indices, then the output will be the average of the two corresponding points in the data set.
Targets Supported
| Name | ADSP-214xx | ADSP-215xx/SC5xx | ADAU145x/146x |
|---|---|---|---|
| —————————— | ——————-- | ——————————-- | —————————- |
| LinearInterPolator | NA | NA | S |
Pins
Input
| Name | Type | Description |
|---|---|---|
| ———————- | ————-- | ———————- |
| InputX | Audio | Input Channel X |
Output
| Name | Type | Description |
|---|---|---|
| ———————- | ————-- | ———————- |
| OutputX | Audio | Output Channel X |
Note:
- X - Channel Index
Configurable Parameters
| GUI Parameter | Default Value | Range | Function Description |
|---|---|---|---|
| —————————————- | ———————- | —————————- | —————————————- |
| NumChannels | 1 | 1 to 24 | Number of channels. Applicable to Nx1 modules. Change in this value requires re-compilation |
| Max | 5 | -15.99 to 15.99 | The maximum allowable input value. For full-scale audio, use 1 |
| Min | -0.06 | -15.99 to Max values 15.99 | The minimum allowable input value. For full-scale audio, use -1. |
| Points | 5 | 2 to 100 | The number of points in the linear interpolation function |
| Table | [1, 2, 3, 4, 5] | -16 to 15.9999999 | The points in the linear interpolation function. The input signal will be mapped to this data set. |
DSP Parameters
| Parameter Name | Description | ADSP-214xx/SC5xx/215xx | ADAU145x/146x |
|---|---|---|---|
| —————————————- | ——————————————————————————-- | —————————————- | —————————- |
| Maximum | The maximum allowable input value | NA | FixPoint8d24 |
| Minimum | The minimum allowable input value | NA | FixPoint8d24 |
| Points | The values of points in the linear interpolation function | NA | FixPoint8d24 |
| Q | Q Factor | NA | FixPoint8d24 |
| Number | The number of points in the linear interpolation function | NA | FixPoint8d24 |
DSP Parameter Computation
Number = (Number of points - 1.0) * 2^-24
Q = 1.0 / (Max- Min)
MinQ = Min * Q
resources/tools-software/sigmastudiov2/modules/basic/linearinterpolator.txt · Last modified: 12 May 2021 17:59 by Nikhin Shetty