canvid.js

canvid is a tiny dependency free library for playback of relatively short videos on canvas elements.

Why not just use HTML5 video?
Because you can't embed and autoplay HTML5 videos on iOS! Yeah, that sucks.
Why is this better than using an animated GIF?
Videos look kind of gross when converted to animated GIFs because of the colors sampling. Also the file size of video GIFs can get pretty huge. GIF is just not made for videos. JPG does a much better job of compressing video frames. Also, animated GIFs don't give you any playback controls. You can't pause a GIF or delay it's playback. With canvid you can do that.
Why only "relatively short" videos?
As you see further down, the container format for canvid is a big image sprite of all the frames of each clip. Sadly, iOS limits the maximum image size (bigger image get sampled down), so that puts a limit on the maximum frames you can store.
Why is there no audio?
canvid doesn't support audio for the same reason animated GIF doesn't support audio either: because that's not what it was built for.

Installation

npm

$ npm install --save canvid

git clone

$ git clone git@github.com:gka/canvid.git

Usage

You can use canvid.js with AMD, CommonJS and browser globals.

var canvidControl = canvid({
    selector : '.video',
    videos: {
        clip1: { src: 'clip1.jpg', frames: 38, cols: 6 },
        clip2: { src: 'clip2.jpg', frames: 43, cols: 6, loops: 3, fps: 24 }
    },
    width: 500,
    height: 400,
    loaded: function() {
        canvidControl.play('clip1');
        // reverse playback
        // canvidControl.play('clip1', true);
    }
});

Options

videos required
Video/Sprite objects (videoKey : videoOptions).
- src required
  Path of the sprite image.
- frames required
  Number of frames.
- cols required
  Number of columns.
- loops optional
  Number of loops.
- fps optional (default: 15)
  Frames per second.
selector optional
The selector of the element where the video gets displayed. You can also pass a DOM element as a selector. default: '.canvid-wrapper'
width optional
Width of the element where the video gets displayed.
default: 800
height optional
Height of the element where the video gets displayed.
default: 450
loaded optional
Function that gets called when all videos are loaded.
srcGif optional
Path of the fallback gif, if canvas is not supported.

Methods

The canvid function returns an object to control the video:

var canvidControl = canvid(canvidOptions);

play
Plays video of the passed videoKey. The parameters isReverse (default: false) and fps (default: 15) are optional.

canvidControl.play(videoKey [,isReverse, fps]);

pause
Pause current video.

canvidControl.pause();

resume
Resume current video.

canvidControl.resume();

destroy
Stops video and removes the canvas of the current canvid element from the DOM.

canvidControl.destroy();

isPlaying
Returns true or false whether the video is playing or not.

canvidControl.isPlaying();

How to convert your video to a JPG sprite

First, convert you video into single frames using ffmpeg:

mkdir frames
ffmpeg -i myvideo.mp4 -vf scale=375:-1 -r 5 frames/%04d.png

Then, use ImageMagicks montage to stich all the frames into one big image:

montage -border 0 -geometry 375x -tile 6x -quality 60% frames/*.png myvideo.jpg

Known Issues

Some users encountered problems on mobile devices with large sprites. A workaround is to split the sprite into multiple sprites.

tocker/canvid