Mobile Meow
Bring YouTube to the Mobile Web
By YouTube's Greg Schechter

Greg Schechter
The Web Warrior
schechter@google.com

Video

Video

A Brief History

Video

Flash

<video>

Video

Playback Stats

Flash Native <video>

Flash
Flash
== Flash

Flash Flash

Native

Native
○ For fallbacks, use rtsp:// protocol (serving .3pg) if the
device won't support HTML5
○ Use custom protocol / URL scheme to launch your own
Android, iOS native app (no Windows Phone yet)
■ youtube://video_id

<video>

The Different Browsers
Safari Android

The Different Browsers
Opera
Safari Android Chrome Silk
Mini
Firefox Opera
IE

The Different Browsers
Opera
Safari Android Chrome Silk
Mini
Firefox Opera
IE
AMP LE
S

By brownpau at http://www.flickr.com/photos/brownpau/533267369/

How do we start
<video>

The Source
<video src="funny_cat_video">

The Source
<video src="funny_cat_video.webm/mp4/ogg">

Mobile Formats Support
Chrome Safari Firefox Opera IE Android
H.264
WebM Android 4+ Android 4+ Android 4+
HLS Android 3+
Platform Versions and Distribution

The Source
<video>
<source src="funny_cat_video.mp4">
<source src="funny_cat_video.webm">
</video>

HLS = HTTP Live Streaming
<video src="playlist.m3u8">

HLS
video-0-1.ts
format-0.m3u8 video-0-2.ts
...
video-1-1.ts
index.m3u8 format-0.m3u8 video-1-2.ts
...
video-2-1.ts
format-0.m3u8 video-2-2.ts
...

HLS
Big Features
○ Live and Adaptive Streaming
○ Built in CDN failover
○ Metadata + Cue Points
Apple App Requirements
○ > 10 minutes in duration or 5 mb in 5 minutes
○ at least one 64 kbps or lower stream required
Tools and more information on Apple's website:
Apple's Using HTTP Live Streaming

Power

Power Consumption: H264 vs WebM
**fullscreen flash
**windowed flash
Research done by Yossi Oren For more information visit http://iss.oy.ne.ro/

Stick it in a page

Basic video tag
Safari
○ Renders a thumbnail poster and play button (flaky)
○ Background is set to black and cannot be overwritten
○ If a parent element has display:none set at any point the video fails to
playback properly
Opera
○ Gives video dimentions black background if the information is
available
○ Has issues with stretching WebM
IE and Android
○ Play button/film icon for all video tags regardless if browser can play
the format
○ Background is set to black/grey and cannot be overwritten

Give it a poster and click it

Poster Attribute
Use the poster attribute to get a thumbnail
Safari, Chrome, Android, and Opera
○ Preserve aspect ratio of poster image
IE and Firefox
○ Stretch image to size of video tag
IE
○ Keeps poster as paused state
All Others
○ Replace video with the paused frame

Basic video tag
Chrome
○ Default click to toggle play/pause
○ Remove with an empty onclick handler
Safari
○ Will launch any supported video with or without an onclick handler
Android and IE
○ Shows click interactions but does not play with empty onclick

Basic video tag
Pro tips:
○ Create your own cued state to convey you can play the video
○ Set the background color to black for continuity across platforms

Controls
<video controls>

Controls
Chrome Safari Firefox Opera IE Android
Play/pause
Button
Volume Only in Mute toggle Don't work in
Controls Fullscreen only Android 4
Seek bar
Fullscreen Button Gesture Button
button
Playback Both Fullscreen Inline only Determined Fullscreen Both
Type only by hardware only

Custom Controls
● Preserve your brand
● Unified experience across platforms and
browsers

Custom Controls
Lets get some custom controls

Custom Controls
● Allows us to expand the set of controls and add our own
○ annotations
○ playlist
○ captions
○ more

Custom Controls Pro Tips
● User expect to be able to drag the progress
bar
○ Need to remender to prevent scroll on touchstart
● Volume can't be set everywhere and users
are accustomed to using device controls
○ So don't build controls for it

Custom Controls Pro Tips
● Fingers are fat
○ Average finger is 11mm so make targets at least
40px with 10px padding
○ Use SVG's so icons can be scaled and shared with
desktop application
○ Do what you can in css

Custom Controls Pro Tips
● Don't trigger content with hover
● Fullscreen
○ The browsing context is always fullscreen so fake it

Fullscreen

requestFullScreen

requestFullScreen
● Desktop Only
○ Firefox, Safari, and Chrome
○ Vendor Prefixed

What about Mobile?

Isn't it already fullscreen?

Yes (sort of)

Mobile Fullscreen
● Open New Tab
● webkitEnterFullscreen
■ Webkit only
■ Video element only
■ metadata must be loaded

Mobile Fullscreen
● Open New Tab
● webkitEnterFullscreen
■ Webkit only
■ Video element only
■ metadata must be loaded
● Pro Tip: Remember size context
changes so use viewport to scale
icons and controls

@viewport { width: device-width; }

autoplay
<video autoplay>

autoplay
In Safari on iOS (for all devices, including iPad),
where the user may be on a cellular network and
be charged per data unit, preload and autoplay are
disabled. No data is loaded until the user initiates it.

What about everyone else?

Autoplay
Chrome Safari Firefox Opera IE Android
Attribute
Scripted Buggy

autoplay

autoplay
<video onclick="this.play()">

autoplay
function someClickEvent(evt) {
// In a user initiated thread.
myVideoElement.load();
getVideoData(); // Triggers an ajax call.
}
function onGetVideoDataReturned(data) {
// Not in a user initiated thread.
setVideoElementSrc(data);
myVideoElement.load();
myVideoElement.play();
}

autoplay
function someClickEvent(evt) {
// In a user initiated thread.
myVideoElement.load();
getVideoData(); // Triggers an ajax call.
}
function onGetVideoDataReturned(data) {
// Not in a user initiated thread.
setVideoElementSrc(data);
myVideoElement.load();
// For Android
window.setTimeout(function() {
myVideoElement.play();
}, 0);
}

Embeds

Embeds
<script>

Embeds
<script>
○ We need our content to be sandboxed
○ More than just a video tag

Embeds
<script>
○ We need our content to be sandboxed
○ More than just a video tag
<object>

Embeds
<script>
○ We need our content to be sandboxed
○ More than just a video tag
<object>
○ Can load content with the data
attribute
○ But no way to interact with it via
JavaScript

Embeds
<iframe>

Embeds
<iframe>
○ Allows our content to be sandboxed
○ JavaScript API communication

Embeds
<iframe type="text/html"
width="640"
height="385"
frameborder="0"
src="http://www.youtube.com/embed/VIDEO_ID"
allowfullscreen>
</iframe>

Embeds
Pro tip: Plan for the future (if you can)
<iframe type="text/html"
width="640"
height="385"
frameborder="0"
src="http://www.youtube.com/embed/VIDEO_ID"
allowfullscreen>
</iframe>

Embeds Pro Tips:
html {
/** Hack to fix iPhone resizing. */
overflow: hidden;
}

Embeds Pro Tips:
body {
/** Dymanic Resizing **/
background-color: #000;
height: 100%;
width: 100%;
/** Remove highlight when use clicks **/
-webkit-tap-highlight-color: rgba(0, 0, 0, 0);
}

Testing

Testing: The Old Fashioned Way
● Device lab
○ accurate
○ costly
○ space inefficient
○ boring

Testing: With Software
● Hardware Emulators / Simulators
○ available for major systems
○ approximation varies
○ still boring
● Android Emulator
○ bulky, slow, no video codecs
● iOs Simulator
○ both tablet and phone

Testing: With Software
● Browser Simulators
○ Poorer approximation
● Opera Mobile Simulator
○ missing video tag support
● Fennec (FF) Simulator
○ poor touch control mapping
○ sends desktop user agent

Testing: Automation
● Selenium!
○ use with simulated or real devices
○ not boring

Testing: Automation
● Android Webdriver
○ Still no video support
● iOS Webdriver
○ Need to register as ios dev
○ Intermittent issues with playback
● IE
○ No webdriver APIs for mobile

Testing: Automation
● Chrome, Opera
○ Driver APIs built-in
○ Remote debugging
● FFMobile
○ No webdriver APIs

Testing: Automation Strategy
● Test API methods in mobile context first
○ cheap
○ can approximate video playback by video.
currentTime

Testing: Automation Strategy
● More sophisticated tests to follow
○ screenreader
● Screen cap processing
○ check for distortion
○ playback accuracy

Testing: Automation Strategy
● Screen cap processing

Testing: Hardware Assistance
for more information check out http://bitbeam.org/

The Future
Cats in Space by WF&TD

Or

PointerEvents
http://msdn.microsoft.com/en-us/library/ie/hh673557(v=vs.85).aspx

http://imgs.xkcd.com/comics/in_ur_reality.png

Track
<video>
<track src="cats_meow" kind="subtitles">
</video>

Camera Access with
getUserMedia

More to learn
● HTML5 Video Spec
○ http://dev.w3.org/html5/spec-author-view/video.html
● Browser Blogs
○ http://dev.opera.com/
○ http://hacks.mozilla.org/
○ http://blogs.msdn.com/b/ie/
○ http://peter.sh/
● Documentation
○ https://developer.mozilla.org/en-US/
● Other
○ http://developer.apple.
com/library/safari/#documentation/AudioVideo/Conceptual/Using_HT
ML5_Audio_Video/Device-SpecificConsiderations/Device-
SpecificConsiderations.html

Questions?
can haz question?
By cloudzilla http://www.flickr.com/photos/cloudzilla/378829651/
schechter@google.com