expyriment.stimuli.Video¶

class expyriment.stimuli.Video(filename, backend=None, position=None)¶

A class implementing a general video stimulus.

This class uses a background thread for playing the video!

__init__(filename, backend=None, position=None)¶

Create a video stimulus.

Parameters:	filename : str filename (incl. path) of the video backend : str, optional ‘mediadecoder’ or ‘pygame’ position : (int, int), optional position of the stimulus

copy()¶

Return a deep copy of the stimulus.

filename¶

Getter for filename.

forward(seconds)¶

Advance playback position.

Parameters:	seconds : int amount to advance (in seconds)

frame¶

Property to get the current available video frame.

has_audio¶

Property to check if video file has audio information.

has_video¶

Property to check if video fifle has video information.

id¶

Getter for id.

is_paused¶

Property to check if video is paused.

is_playing¶

Property to check if video is playing.

is_preloaded¶

Getter for is_preloaded.

length¶

Property to get the length of the video.

logging¶

Getter for logging.

new_frame_available¶

Property to check if new video frame is available to render.

pause()¶

Pause the video stimulus.

play(loop=False, log_event_tag=None)¶

Play the video stimulus from the current position.

Parameters:	loop : bool, optional loop video playback (will be ignored when using play to unpause!) log_event_tag : numeral or string, optional if log_event_tag is defined and if logging is switched on for this stimulus (default), a summary of the inter-event-intervalls are appended at the end of the event file

position¶

Getter for position.

preload()¶

Preload stimulus to memory.

present()¶

Present current frame.

This method waits for the next frame and presents it on the screen. When using OpenGL, the method blocks until this frame is actually being written to the screen.

rewind()¶

Rewind to start of video stimulus.

set_logging(onoff)¶

Set logging of this object on or off

Parameters:	onoff : bool set logging on (True) or off (False)

Notes

See also design.experiment.set_log_level fur further information about event logging.

size¶

Property to get the resolution of the video.

stop()¶

Stop the video stimulus.

time¶

Property to get the current playback time.

unload(**kwargs)¶

Unload stimulus from memory.

This removes the reference to the object in memory. It is up to the garbage collector to actually remove it from memory.

update()¶

Update the screen.

wait_end(callback_function=None, process_control_events=True)¶

Wait until video has ended and constantly update screen.

Parameters:	callback_function : function, optional function to repeatedly execute during waiting loop process_control_events : bool, optional process io.Keyboard.process_control_keys() and io.Mouse.process_quit_event() (default = True)

Notes

This will also by default process control events (quit and pause). Thus, keyboard events will be cleared from the cue and cannot be received by a Keyboard().check() anymore! If keybaord events should not be cleared, a loop has to be created manually like:

video.present()
while video.is_playing and video.frame < frame:
    while not video.new_frame_available:
        key = exp.keyboard.check()
        if key == ...
    video.update()
video.stop()

wait_frame(frame, callback_function=None, process_control_events=True)¶

Wait until certain frame was shown and constantly update screen.

Parameters:	frame : int number of the frame to stop after callback_function : function, optional function to repeatedly execute during waiting loop process_control_events : bool, optional process io.Keyboard.process_control_keys() and io.Mouse.process_quit_event() (default = True)

Notes

This will also by default process control events (quit and pause). Thus, keyboard events will be cleared from the cue and cannot be received by a Keyboard().check() anymore! If keybaord events should not be cleared, a loop has to be created manually like:

video.present()
while video.is_playing and video.frame < frame:
    while not video.new_frame_available:
        key = exp.keyboard.check()
        if key == ...
    video.update()
video.stop()