Read one or more video frames
Create a video reader object and read one or more video frames using the frame indices.
Create a VideoReader object for the example movie file xylophone.mp4.
v = VideoReader('xylophone.mp4');Read only the first video frame.
frame = read(v,1);
Read only the last video frame.
frame = read(v,Inf);
Read frames 5 through 10.
frames = read(v,[5 10]);
Read from the 50th frame to the end of the video file.
frames = read(v,[50 Inf]);
v — Input VideoReader objectVideoReader objectInput VideoReader object. Use the VideoReader function to
create a VideoReader object from your video file.
index — Frames to read[1 Inf] (default) | numeric scalar | two-element arrayFrames to read, specified as a numeric scalar or a two-element array.
To read a single frame, specify a numeric scalar.
To read a range of frames, specify a two-element array.
The first frame number is 1, and Inf represents the
last frame of the file.
Example: 10
Example: Inf
Example: [1 20]
Data Types: single | double | int8 | int16 | int32 | int64 | uint8 | uint16 | uint32 | uint64
'native' — Flag to use format specified in VideoFormat propertyFlag to use format specified in VideoFormat property,
specified as the character vector or a string scalar,
'native'.
Data Types: char | string
video — Video frame dataVideo frame data, returned as a numeric or structure array. The size and
format of video depends on the
VideoFormat property of v. When
the VideoFormat property of v is
'Indexed' or 'Grayscale', the data
type and dimensions of video depend on whether you call
read with the 'native' argument.
For most files, the data type and dimensions of video are
as follows.
H is the image frame height, W is
the image frame width, and F is the number of frames
read.
Value of
obj.VideoFormat | Data Type of
video | Dimensions of
video | Description |
|---|---|---|---|
'RGB24', with or without specifying
'native' | uint8 |
| RGB24 image |
'Grayscale', without specifying
'native' | uint8 |
| Grayscale image |
'Indexed', without specifying
'native' | uint8 |
| RGB24 image |
'Grayscale' or
'Indexed', specifying
'native' | struct | 1-by- | MATLAB® movie, which is an array of frame
structure arrays, each containing the fields
|
For Motion JPEG 2000 files, the data type and dimensions of
video are as follows.
Value of
obj.VideoFormat | Data Type of
video | Dimensions of
video | Description |
|---|---|---|---|
'Mono8' | uint8 |
| Mono image |
'Mono8 Signed' | int8 |
| Mono signed image |
'Mono16' | uint16 |
| Mono image |
'Mono16 Signed' | int16 |
| Mono signed image |
'RGB24' | uint8 |
| RGB24 image |
'RGB24 Signed' | int8 |
| RGB24 signed image |
'RGB48' | uint16 |
| RGB48 image |
'RGB48 Signed' | int16 |
| RGB48 signed image |
Usage notes and limitations:
Code generation for read does not support
the optional positional argument native.
Generate Code That Uses Row-Major Layout — Generate Code That Uses Row-Major Array Layout (MATLAB Coder).
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