View Source Evision.VideoWriter (Evision v0.1.9)
Link to this section Summary
cv
Concatenates 4 chars to a fourcc code
Returns the specified VideoWriter property
Returns used backend API name
Returns true if video writer has been successfully initialized.
Initializes or reinitializes video writer.
Variant 1:
Positional Arguments
- filename:
String
- fourcc:
int
- fps:
double
- frameSize:
Size
- params:
[int]
Has overloading in C++
Variant 1:
Positional Arguments
- filename:
String
- apiPreference:
int
- fourcc:
int
- fps:
double
- frameSize:
Size
- params:
[int]
Has overloading in C++
Closes the video writer.
Sets a property in the VideoWriter.
Default constructors
Positional Arguments
filename:
String
.
Variant 1:
Positional Arguments
- filename:
String
- fourcc:
int
- fps:
double
- frameSize:
Size
- params:
[int]
Has overloading in C++
Variant 1:
Positional Arguments
- filename:
String
- apiPreference:
int
- fourcc:
int
- fps:
double
- frameSize:
Size
- params:
[int]
Has overloading in C++
Writes the next video frame
Functions
Raising version of fourcc/4
.
Raising version of get/2
.
Raising version of getBackendName/1
.
Raising version of isOpened/1
.
Raising version of open/5
.
Raising version of open/6
.
Raising version of open/7
.
Raising version of release/1
.
Raising version of set/3
.
Raising version of videoWriter/0
.
Raising version of videoWriter/4
.
Raising version of videoWriter/5
.
Raising version of videoWriter/6
.
Raising version of write/2
.
Link to this section cv
Concatenates 4 chars to a fourcc code
Positional Arguments
- c1:
char
- c2:
char
- c3:
char
- c4:
char
@return a fourcc code This static method constructs the fourcc code of the codec to be used in the constructor VideoWriter::VideoWriter or VideoWriter::open.
Python prototype (for reference):
fourcc(c1, c2, c3, c4) -> retval
Returns the specified VideoWriter property
Positional Arguments
propId:
int
.Property identifier from cv::VideoWriterProperties (eg. cv::VIDEOWRITER_PROP_QUALITY) or one of @ref videoio_flags_others
@return Value for the specified property. Value 0 is returned when querying a property that is not supported by the backend used by the VideoWriter instance.
Python prototype (for reference):
get(propId) -> retval
Returns used backend API name
Note: Stream should be opened.
Python prototype (for reference):
getBackendName() -> retval
Returns true if video writer has been successfully initialized.
Python prototype (for reference):
isOpened() -> retval
Initializes or reinitializes video writer.
Positional Arguments
- filename:
String
- fourcc:
int
- fps:
double
- frameSize:
Size
Keyword Arguments
- isColor:
bool
.
The method opens video writer. Parameters are the same as in the constructor
VideoWriter::VideoWriter.
@return true
if video writer has been successfully initialized
The method first calls VideoWriter::release to close the already opened file.
Python prototype (for reference):
open(filename, fourcc, fps, frameSize[, isColor]) -> retval
Variant 1:
Positional Arguments
- filename:
String
- fourcc:
int
- fps:
double
- frameSize:
Size
- params:
[int]
Has overloading in C++
Python prototype (for reference):
open(filename, fourcc, fps, frameSize, params) -> retval
Variant 2:
Positional Arguments
- filename:
String
- apiPreference:
int
- fourcc:
int
- fps:
double
- frameSize:
Size
Keyword Arguments
- isColor:
bool
.
Has overloading in C++
Python prototype (for reference):
open(filename, apiPreference, fourcc, fps, frameSize[, isColor]) -> retval
Variant 3:
Initializes or reinitializes video writer.
Positional Arguments
- filename:
String
- fourcc:
int
- fps:
double
- frameSize:
Size
Keyword Arguments
- isColor:
bool
.
The method opens video writer. Parameters are the same as in the constructor
VideoWriter::VideoWriter.
@return true
if video writer has been successfully initialized
The method first calls VideoWriter::release to close the already opened file.
Python prototype (for reference):
open(filename, fourcc, fps, frameSize[, isColor]) -> retval
Variant 1:
Positional Arguments
- filename:
String
- apiPreference:
int
- fourcc:
int
- fps:
double
- frameSize:
Size
- params:
[int]
Has overloading in C++
Python prototype (for reference):
open(filename, apiPreference, fourcc, fps, frameSize, params) -> retval
Variant 2:
Positional Arguments
- filename:
String
- apiPreference:
int
- fourcc:
int
- fps:
double
- frameSize:
Size
Keyword Arguments
- isColor:
bool
.
Has overloading in C++
Python prototype (for reference):
open(filename, apiPreference, fourcc, fps, frameSize[, isColor]) -> retval
Closes the video writer.
The method is automatically called by subsequent VideoWriter::open and by the VideoWriter destructor.
Python prototype (for reference):
release() -> None
Sets a property in the VideoWriter.
Positional Arguments
propId:
int
.Property identifier from cv::VideoWriterProperties (eg. cv::VIDEOWRITER_PROP_QUALITY) or one of @ref videoio_flags_others
value:
double
.Value of the property.
@return true
if the property is supported by the backend used by the VideoWriter instance.
Python prototype (for reference):
set(propId, value) -> retval
Default constructors
The constructors/functions initialize video writers.
- On Linux FFMPEG is used to write videos;
- On Windows FFMPEG or MSWF or DSHOW is used;
- On MacOSX AVFoundation is used.
Python prototype (for reference):
VideoWriter() -> <VideoWriter object>
Positional Arguments
filename:
String
.Name of the output video file.
fourcc:
int
.4-character code of codec used to compress the frames. For example, VideoWriter::fourcc('P','I','M','1') is a MPEG-1 codec, VideoWriter::fourcc('M','J','P','G') is a motion-jpeg codec etc. List of codes can be obtained at Video Codecs by FOURCC page. FFMPEG backend with MP4 container natively uses other values as fourcc code: see ObjectType, so you may receive a warning message from OpenCV about fourcc code conversion.
fps:
double
.Framerate of the created video stream.
frameSize:
Size
.Size of the video frames.
Keyword Arguments
isColor:
bool
.If it is not zero, the encoder will expect and encode color frames, otherwise it will work with grayscale frames.
Has overloading in C++
@b Tips:
With some backends
fourcc=-1
pops up the codec selection dialog from the system.To save image sequence use a proper filename (eg.
img_%02d.jpg
) andfourcc=0
ORfps=0
. Use uncompressed image format (eg.img_%02d.BMP
) to save raw frames.Most codecs are lossy. If you want lossless video file you need to use a lossless codecs (eg. FFMPEG FFV1, Huffman HFYU, Lagarith LAGS, etc...)
If FFMPEG is enabled, using
codec=0; fps=0;
you can create an uncompressed (raw) video file.
Python prototype (for reference):
VideoWriter(filename, fourcc, fps, frameSize[, isColor]) -> <VideoWriter object>
Variant 1:
Positional Arguments
- filename:
String
- fourcc:
int
- fps:
double
- frameSize:
Size
- params:
[int]
Has overloading in C++
The params
parameter allows to specify extra encoder parameters encoded as pairs (paramId_1, paramValue_1, paramId_2, paramValue_2, ... .)
see cv::VideoWriterProperties
Python prototype (for reference):
VideoWriter(filename, fourcc, fps, frameSize, params) -> <VideoWriter object>
Variant 2:
Positional Arguments
- filename:
String
- apiPreference:
int
- fourcc:
int
- fps:
double
- frameSize:
Size
Keyword Arguments
- isColor:
bool
.
Has overloading in C++
The apiPreference
parameter allows to specify API backends to use. Can be used to enforce a specific reader implementation
if multiple are available: e.g. cv::CAP_FFMPEG or cv::CAP_GSTREAMER.
Python prototype (for reference):
VideoWriter(filename, apiPreference, fourcc, fps, frameSize[, isColor]) -> <VideoWriter object>
Variant 3:
Positional Arguments
filename:
String
.Name of the output video file.
fourcc:
int
.4-character code of codec used to compress the frames. For example, VideoWriter::fourcc('P','I','M','1') is a MPEG-1 codec, VideoWriter::fourcc('M','J','P','G') is a motion-jpeg codec etc. List of codes can be obtained at Video Codecs by FOURCC page. FFMPEG backend with MP4 container natively uses other values as fourcc code: see ObjectType, so you may receive a warning message from OpenCV about fourcc code conversion.
fps:
double
.Framerate of the created video stream.
frameSize:
Size
.Size of the video frames.
Keyword Arguments
isColor:
bool
.If it is not zero, the encoder will expect and encode color frames, otherwise it will work with grayscale frames.
Has overloading in C++
@b Tips:
With some backends
fourcc=-1
pops up the codec selection dialog from the system.To save image sequence use a proper filename (eg.
img_%02d.jpg
) andfourcc=0
ORfps=0
. Use uncompressed image format (eg.img_%02d.BMP
) to save raw frames.Most codecs are lossy. If you want lossless video file you need to use a lossless codecs (eg. FFMPEG FFV1, Huffman HFYU, Lagarith LAGS, etc...)
If FFMPEG is enabled, using
codec=0; fps=0;
you can create an uncompressed (raw) video file.
Python prototype (for reference):
VideoWriter(filename, fourcc, fps, frameSize[, isColor]) -> <VideoWriter object>
videoWriter(filename, apiPreference, fourcc, fps, frameSize, opts)
View SourceVariant 1:
Positional Arguments
- filename:
String
- apiPreference:
int
- fourcc:
int
- fps:
double
- frameSize:
Size
- params:
[int]
Has overloading in C++
Python prototype (for reference):
VideoWriter(filename, apiPreference, fourcc, fps, frameSize, params) -> <VideoWriter object>
Variant 2:
Positional Arguments
- filename:
String
- apiPreference:
int
- fourcc:
int
- fps:
double
- frameSize:
Size
Keyword Arguments
- isColor:
bool
.
Has overloading in C++
The apiPreference
parameter allows to specify API backends to use. Can be used to enforce a specific reader implementation
if multiple are available: e.g. cv::CAP_FFMPEG or cv::CAP_GSTREAMER.
Python prototype (for reference):
VideoWriter(filename, apiPreference, fourcc, fps, frameSize[, isColor]) -> <VideoWriter object>
Writes the next video frame
Positional Arguments
image:
Evision.Mat
.The written frame. In general, color images are expected in BGR format.
The function/method writes the specified image to video file. It must have the same size as has been specified when opening the video writer.
Python prototype (for reference):
write(image) -> None
Link to this section Functions
Raising version of fourcc/4
.
Raising version of get/2
.
Raising version of getBackendName/1
.
Raising version of isOpened/1
.
Raising version of open/5
.
Raising version of open/6
.
open!(self, filename, apiPreference, fourcc, fps, frameSize, params)
View SourceRaising version of open/7
.
Raising version of release/1
.
Raising version of set/3
.
Raising version of videoWriter/0
.
Raising version of videoWriter/4
.
Raising version of videoWriter/5
.
videoWriter!(filename, apiPreference, fourcc, fps, frameSize, params)
View SourceRaising version of videoWriter/6
.
Raising version of write/2
.