#094 Scripting YouTube

An experiment in scripting the YouTube player with external controls and the IFrame API.

Notes

I have some ideas for how I’d like to be able to embed YouTube, but they hinge on the ability to control a YouTube player and also get feedback on current player position. this is a quick test to see if all these possibilities are realistic.

A quick search yeilded the YouTube Player API Reference for iframe Embeds, which appears to be the right medicine. So that’s what I’m going to try..

Objectives:

external play trigger
mark times
play section between marked times
loop between marked times

Some Useful Features of the API

onYouTubeIframeAPIReady is a function that must be implemented. It is called by the API when loaded and ready.

Playback controls include

player.playVideo():Void
player.pauseVideo():Void
player.stopVideo():Void
player.seekTo(seconds:Number, allowSeekAhead:Boolean):Void

Playback status

player.getPlayerState():Number
player.getCurrentTime():Number

Mark and Loop

The getCurrentTime() function gets the appropriate video position for a “Mark” operation.

Rewind/set to play from a specific time mark can be achieved with the seekTo() function.

It seems there’s no direct way to directly combine an end time with seekTo().

To play a specific time window (from startSeconds to endSeconds) appears only to be directly supported by the loadVideoById and cueVideoById functions. But these entail reloading the entire video, so not ideal for performing a loop between start/end in an already-loaded video.

So the approach that appears best is:

use getCurrentTime() to mark start/end points
start a loop with seekTo(), and use setTimeout to fire at approximately the desired end point.
at the end point, either stop the video or loop back with another seekTo() depending on whether infinite looping is desired.

An Example

The example.html loads a preset video, initially stopped, and enables some simple controls. Only plain-old-Javascript and the IFrame API are used.

Play, Pause and Stop buttons have their expected effect.

A Mark button is use to set/reset the start and end markers.

when the second mark has been added, it will automatically replay the video between the two marks
if the ‘loop’ checkbox is selected, the video will loop between the two marks

Credits and References