jsPsych/plugins/jspsych-video.js

147 lines
3.8 KiB
JavaScript

/* jspsych-video.js
* Josh de Leeuw
*
* This plugin displays a video. The trial ends when the video finishes.
*
* documentation: docs.jspsych.org
*
*/
jsPsych.plugins.video = (function() {
var plugin = {};
plugin.info = {
name: 'video',
description: '',
parameters: {
sources: {
type: jsPsych.plugins.parameterType.VIDEO,
pretty_name: 'Sources',
array: true,
default: undefined,
description: 'The video file to play.'
},
width: {
type: jsPsych.plugins.parameterType.INT,
pretty_name: 'Width',
default: undefined,
description: 'The width of the video in pixels.'
},
height: {
type: jsPsych.plugins.parameterType.INT,
pretty_name: 'Height',
default: undefined,
description: 'The height of the video display in pixels.'
},
autoplay: {
type: jsPsych.plugins.parameterType.BOOL,
pretty_name: 'Autoplay',
default: true,
description: 'If true, the video will begin playing as soon as it has loaded.'
},
controls: {
type: jsPsych.plugins.parameterType.BOOL,
pretty_name: 'Controls',
default: false,
description: 'If true, the subject will be able to pause the video or move the playback to any point in the video.'
},
prompt: {
type: jsPsych.plugins.parameterType.STRING,
pretty_name: 'Prompt',
default: null,
description: 'Any content here will be displayed below the video content.'
},
start: {
type: jsPsych.plugins.parameterType.FLOAT,
pretty_name: 'Start',
default: null,
description: 'Time to start the clip.'
},
stop: {
type: jsPsych.plugins.parameterType.FLOAT,
pretty_name: 'Stop',
default: null,
description: 'Time to stop the clip.'
}
}
}
plugin.trial = function(display_element, trial) {
// display stimulus
var video_html = '<video id="jspsych-video-player" width="'+trial.width+'" height="'+trial.height+'" '
if(trial.autoplay){
video_html += "autoplay "
}
if(trial.controls){
video_html +="controls "
}
video_html+=">"
for(var i=0; i<trial.sources.length; i++){
var s = trial.sources[i];
if(s.indexOf('?') > -1){
s = s.substring(0, s.indexOf('?'));
}
var type = s.substr(s.lastIndexOf('.') + 1);
type = type.toLowerCase();
// adding start stop parameters if specified
video_html+='<source src="'+trial.sources[i]
if (trial.start !== null) {
video_html+= '#t=' + trial.start;
} else {
video_html+= '#t=0';
}
if (trial.stop !== null) {
video_html+= ',' + trial.stop
}
video_html+='" type="video/'+type+'">';
}
video_html +="</video>"
//show prompt if there is one
if (trial.prompt !== null) {
video_html += trial.prompt;
}
display_element.innerHTML = video_html;
display_element.querySelector('#jspsych-video-player').onended = function(){
end_trial();
}
// event handler to set timeout to end trial if video is stopped
display_element.querySelector('#jspsych-video-player').onplay = function(){
if(trial.stop !== null){
if(trial.start == null){
trial.start = 0;
}
jsPsych.pluginAPI.setTimeout(end_trial, (trial.stop-trial.start)*1000);
}
}
// function to end trial when it is time
var end_trial = function() {
// gather the data to store for the trial
var trial_data = {
stimulus: JSON.stringify(trial.sources)
};
// clear the display
display_element.innerHTML = '';
// move on to the next trial
jsPsych.finishTrial(trial_data);
};
};
return plugin;
})();