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From Multimedia File

Read video frames and audio samples from multimedia file

  • Library:
  • Computer Vision Toolbox / Sources

  • From Multimedia File block

Description

The From Multimedia File block reads video frames, audio samples, or both from a multimedia file. The block imports data from a file, of a supported file format, into a Simulink® model. For more information about supported file formats, see Supported Platforms and File Formats.

This block enables you to read WMA or WMV streams from your system or over a network connection. Similarly, the To Multimedia File block enables you to write WMA or WMV streams to your system or over a network connection. If your system does not have the codec necessary to support a file format, you must re-encode files of that format into a file format supported by the Computer Vision Toolbox™.

If you have a Simulink Coder™ license, you can generate code from a model containing this block. To run a generated executable file, you may need to add precompiled shared library files to your system path. For more information, see Simulink Shared Library Dependencies and Accelerating Simulink Models.

Note

This block supports code generation for a host computer that has file I/O available. You cannot use this block with Simulink Desktop Real-Time™ software because that product does not support file I/O.

Ports

Output

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Color image or video frame, returned as an M-by-N-by-P array. M and N are the number of rows and columns in each image. P is the number of color channels in each image.

Dependencies

To enable this port:

  • Set the File name parameter to the name of a multimedia file that contains video or image data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Video only or Video and audio.

  • Set the Output color format parameter to RGB and Image signal parameter to One multidimensional signal.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32 | Simulink.ImageType

Grayscale image or video frame, returned as an M-by-N matrix. M and N are the number of rows and columns in the grayscale image.

Dependencies

To enable this port:

  • Set the File name parameter to the name of a multimedia file that contains video or image data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Video only or Video and audio.

  • Set the Output color format parameter to Intensity.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32

Red color component of the image or video frame, returned as an M-by-N matrix. M and N are the number of rows and columns in the image.

Dependencies

To enable this port:

  • Set the File name parameter to the name of a multimedia file that contains video or image data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Video only or Video and audio.

  • Set the Output color format parameter to RGB and Image signal parameter to Separate color signals.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32

Green color component of the image or video frame, returned as an M-by-N matrix. M and N are the number of rows and columns in the image.

Dependencies

To enable this port:

  • Set the File name parameter to the name of a multimedia file that contains video or image data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Video only or Video and audio.

  • Set the Output color format parameter to RGB and Image signal parameter to Separate color signals.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32

Blue color component of the image or video frame, returned as an M-by-N matrix. M and N are the number of rows and columns in the image.

Dependencies

To enable this port:

  • Set the File name parameter to the name of a multimedia file that contains video or image data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Video only or Video and audio.

  • Set the Output color format parameter to RGB and Image signal parameter to Separate color signals.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32

Luma component of the image or video frame, returned as an M-by-N matrix. M and N are the number of rows and columns in the image.

Dependencies

To enable this port:

  • Set the File name parameter to the name of a multimedia file that contains video or image data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Video only or Video and audio.

  • Set the Output color format parameter to YCbCr 4:2:2.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32

Blue-difference chrominance component of the image or video frame, returned as an M-by-N/2 matrix. M and N are the number of rows and columns in the input image.

Dependencies

To enable this port:

  • Set the File name parameter to the name of a multimedia file that contains video or image data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Video only or Video and audio.

  • Set the Output color format parameter to YCbCr 4:2:2.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32

Red-difference chrominance component of the image or video frame, returned as an M-by-N/2 matrix. M and N are the number of rows and columns in each input image.

Dependencies

To enable this port:

  • Set the File name parameter to the name of a multimedia file that contains video or image data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Video only or Video and audio.

  • Set the Output color format parameter to YCbCr 4:2:2.

Data Types: single | double | int8 | int16 | int32 | uint8 | uint16 | uint32

Audio signal, returned as an M-element vector or an M-by-N matrix. M is the number of samples in each channel and N is the number of channels.

Dependencies

To enable this port, set the File name parameter to the name of a multimedia file that contains audio data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Audio only or Video and audio.

Data Types: single | double | int16 | uint8

End-of-file indicator, returned as a logical scalar for each video frame or audio sample. The end-of-file indicator is 1 when the block outputs the final video frame or audio sample from the file, and is 0 otherwise.

Dependencies

To enable this port, select the Output end-of-file indicator parameter.

Data Types: Boolean

Parameters

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Main

Specify the name of the multimedia file for the block to read. If the file is not located on your MATLAB® path, select Browse and navigate to the file, or specify the full file path.

On Microsoft® Windows® platforms, this parameter supports URLs that point to Microsoft Media Server (MMS) streams.

Specify whether the block inherits the sample time from the multimedia file or uses a specified sample time. When you select this parameter, the block inherits the sample time from the input multimedia file.

Tip

Select this parameter when you do not know the intended sample rate of the multimedia file.

Specify a sample time for the block.

Dependencies

To enable this parameter, clear the Inherit sample time from file parameter.

Specify the number of times to play the input multimedia file. The default value of inf specifies that the block repeats playing the multimedia file until the simulation stop time.

Select this parameter to enable the EOF port, which indicates whether the output frame or sample is the final video frame or audio sample in the multimedia file.

Specify the type of media to read from a file containing both video and audio data.

Dependencies

To enable this parameter, set the File name parameter to the name of a multimedia file that contains both audio and video data.

Specify the output color format of the input video data. The block supports the RGB, Intensity, and YCbCr 4:2:2 color formats.

Dependencies

To enable this parameter, set the File name parameter to the name of a multimedia file that contains video data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Video only or Video and audio.

Specify how the block outputs an RGB color video. If you select One multidimensional signal, the block outputs the video data using only the Image port. If you select Separate color signals, the block outputs the video data using three separate color channels, divided across the R, G, and B ports. If you select Simulink image signal, the block outputs a video in Simulink.ImageType datatype.

Dependencies

To enable this parameter:

  • Set the File name parameter to the name of a multimedia file that contains video data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Video only or Video and audio.

  • Set the Output color format parameter to RGB.

Specify the range of audio samples to read from the input file as a two-element row vector of the form [StartSample EndSample]. StartSample is the first sample the block reads from the audio file, and EndSample is the final sample the block reads from the audio file. StartSample must be greater than or equal to 1. EndSample must be greater than StartSample.

Dependencies

To enable this parameter, set the File name parameter to the name of a multimedia file that contains audio data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Audio only.

Specify the number of samples per audio channel.

Dependencies

To enable this parameter, set the File name parameter to the name of a multimedia file that contains audio data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Audio only.

Data Types

Specify the data type for the output video frames.

Dependencies

To enable this parameter, set the File name parameter to the name of a multimedia file that contains video data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Video only or Video and audio.

Specify the data type for the output audio samples.

Dependencies

To enable this parameter, set the File name parameter to the name of a multimedia file that contains audio data. If the specified file contains both audio and video data, set the Multimedia outputs parameter to Audio only or Video and audio.

Block Characteristics

Data Types

double | integer[a] | single

Direct Feedthrough

no

Multidimensional Signals

no

Variable-Size Signals

no

Zero-Crossing Detection

no

[a] Supports 16- and 32-bit signed and 8-bit unsigned integers.

More About

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Extended Capabilities

Introduced before R2006a