To Multimedia File
Stream video frames and audio samples to multimedia file
The To Multimedia File block writes video frames, audio samples, or both to
a multimedia (
.avi, .wav, .wma, .mp4, .ogg, .flac, or .wmv) file.
You can compress the video frames or audio samples by selecting a compression algorithm. You can connect as many of the input ports as you want. Therefore, you can control the type of video and/or audio the multimedia file receives.
This block supports code generation for platforms that have file I/O available. You cannot use this block with Simulink® Desktop Real-Time™ software, because that product does not support file I/O.
This block performs best on platforms with Version 11 or later of Windows Media® Player software. This block supports only uncompressed RGB24 AVI files on Linux® and Mac platforms.
Windows® 7 UAC (User Account Control), may require administrative privileges to encode
The generated code for this block relies on prebuilt library files. You can run this code
outside the MATLAB® environment, or redeploy it, but be sure to account for these extra library
files when doing so. The packNGo function creates a single zip file containing all of the
pieces required to run or rebuild this code. See
packNGo (Simulink Coder) for more information.
To run an executable file that was generated from a model containing this block, you may need to add precompiled shared library files to your system path. See Understanding C Code Generation in DSP System Toolbox for details.
Cross-Platform Supported File Formats for Audio Files
Audio files can be of the following formats on all platforms:
MPEG4 (only on Windows 7 and macOS)
The default format is WAV. This block supports MPEG-4 AAC audio files on Windows 7, and macOS. You can use both M4A and MP4 extensions. The following platform specific restrictions apply when writing these files:
M-by-N-by-3 matrix RGB, Intensity, or YCbCr 4:2:2 signal.
R, G, B
Matrix that represents one plane of the RGB video stream. Inputs to the R, G, or B port must have the same dimensions and data type.
M-by-N matrix. M is the number of samples in each channel, and N is the number of channels.
Y, Cb, Cr
Matrix that represents one frame of the YCbCr video stream. The Y, Cb, and Cr ports use the following dimensions:
The Main pane of the To Multimedia File block dialog appears as follows.
- File name
Specify the name of the multimedia file. The block saves the file in your current folder. To specify a different file or location, click the Save As... button.
- File type
Specify the file type of the multimedia file. You can select
OGG. By default, the File type is set to
Specify whether the block writes video frames, audio samples, or both to the multimedia file. You can select
Video and audio,
Video only, or
Audio only. This parameter is visible only when you set File type to
- Audio compressor
Select the type of compression algorithm to use to compress the audio data. This compression reduces the size of the multimedia file. Choose
None (uncompressed)to save uncompressed audio data to the multimedia file.
The other items available in this parameter list are the audio compression algorithms installed on your system. For information about a specific audio compressor, see the documentation for that compressor.
- Audio data type
Select the audio data type. You can use the Audio data type parameter only for uncompressed wave files.
- Video compressor
Select the type of compression algorithm to use to compress the video data. This compression reduces the size of the multimedia file. Choose
None (uncompressed)to save uncompressed video data to the multimedia file.
The other items available in this parameter list are the video compression algorithms installed on your system. For information about a specific video compressor, see the documentation for that compressor.
- Compression Factor (>1)
Specify the compression factor as an integer scalar greater than
1. This parameter is applicable only when the File type is set to
MJ2000and Video compressor is set to
Lossy. By default, this parameter is set to
- File color format
Select the color format of the data stored in the file. You can select either
- Image signal
Specify how the block accepts a color video signal. If you select
One multidimensional signal, the block accepts an M-by-N-by-P color video signal, where P is the number of color planes, at one port. If you select
Separate color signals, additional ports appear on the block. Each port accepts one M-by-N plane of an RGB video stream.
- Video Quality (0-100)
Quality of the video specified as an integer scalar in the range [
0 100]. This parameter is applicable only when File name is set to
MPEG4and Write is set to
Video only. By default, this parameter is set to
Running an Executable Outside MATLAB
To run your generated standalone executable application in Shell, you need to set your environment to the following:
For more information, see Append library path to "DYLD_LIBRARY_PATH" in MAC.
Supported Data Types
For the block to display video data properly, double- and single-precision floating-point
pixel values must be between
1. Any other
data type requires the pixel values between the minimum and maximum values supported by their
Check the specific codecs you are using for supported audio rates.
|Port||Supported Data Types||Supports Complex Values?|
R, G, B
Same as Image port
Y, Cb, Cr
Same as Image port
C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.
Usage notes and limitations:
Host computer only. Excludes Simulink Desktop Real-Time code generation.
The executable generated from this block relies on prebuilt dynamic library files (
.dllfiles) included with MATLAB. Use the
packNGofunction to package the code generated from this block and all the relevant files in a compressed zip file. Using this zip file, you can relocate, unpack, and rebuild your project in another development environment where MATLAB is not installed. For more details, see How To Run a Generated Executable Outside MATLAB.