Audio Capture

Capture audio samples from an input audio device and send to an algorithm

Since R2021a

• 

Libraries:
SoC Blockset / Processor I/O

Description

The Audio Capture block simulates behavior of the driver code that captures samples of an audio stream on an hardware board. The input of this block must be connected to an Audio Capture Interface block that simulates the physical audio device on a hardware board. Place this block inside a task and connect to an algorithm to process a frame of audio samples each time the task executes. For more information on tasks, see Timer-Driven Task and Event-Driven Tasks.

Ports

Input

msg — Data message from audio capture interface

scalar

This message port receives data messages from a connected Audio Capture Interface block. The messages process when the Task Manager block triggers the task containing the Audio Capture block. For more information on messages, see Messages.

Data Types: SoCData

Output

data — Data frame from captured audio

M-element vector | M-by-C matrix

When block receives a single audio channel, data is an M-element audio data frame received from a simulated hardware audio source. The Samples per frame parameter defines the number of samples, M, of audio data. When the block receives multiple audio channels, the audio data is an M-by-C matrix, where C is specified by the Number of channels parameter.

Data Types: int8 | int16 | int32

Parameters

Data type — Data type of audio device

int16 (default) | int8 | int32

Specify the data type for the audio capture device.

Number of channels — Number of data channels

2 (default) | positive integer

Specify the number of audio channels, C, received from the audio device. This number should match the Number of channels parameter in the Audio Capture Interface block.

Samples per frame — Size of data vector read from audio device

4410 (default) | positive scalar integer

Specify the number samples per frame, M, of audio data received.

Sample time — Sample time in seconds

-1 (default) | positive scalar

If used in a timer-driven task, enter the sample time of the task defined in the Task Manager block. If used in the event-driven task, enter -1.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using Simulink® Coder™.

• To automatically generate C code for your design, and execute on an SoC device, use the SoC Builder tool. For more information on generating code for SoC designs, see Use SoC Builder to Generate SoC Design.

• To generate and execute C code for your SoC models, this block requires Embedded Coder^® and SoC Blockset™ Support Package for Embedded Linux^® Devices.

• To use this block, you must set Hardware Board to Embedded Linux Board. You can then follow the instructions to configure the board. For more information, see Create an Embedded Linux Device Configuration.

When deployed to a supported hardware board, this block uses the V4L2 driver framework to capture images from video capture devices, such as a camera. To specify the video capture device and event triggers, use the Hardware Mapping tool. For more information on the V4L2 driver framework, see Video4Linux.

Version History

Introduced in R2021a