HTML5, Flash, and the Battle for Faster Cat Videos HTML5 と Flash を比較する: YouTube 動画を高速化するテクノロジー

1. HTML5, Flash and the Battle for
Faster Cat Videos
By YouTube's Greg Schechter, Phil Harnish and
Matt Ward

2. Greg Schechter Phil Harnish Matt Ward
The Web Warrior Sr. Play Button Seek Bar
Eng Engineer
schechter@google. mattward@google.
com philharnish@google.com
com

4. HTML + JS + CSS + Awesomeness

5. HTML5
Offline File Access Multimedia Performance
Presentation Graphics Storage

6. HTML5
Offline File Access Multimedia Performance
Presentation Graphics Storage

7. Translation

8. HTML5 ~=
By geishaboy500
http://www.flickr.com/photos/geishaboy500/3183872667/

9. 99% connected desktop penetration?
http://www.adobe.com/products/player_census/flashplayer/

10. Why HTML5?

11. HTML5 vs Flash
Features Accessibility "Device-ability"
Security Embeds API

12. Round 1: Features
http://www.flickr.
com/photos/zipckr/4624150058/

13. Why Flash?
Features missing in HTML5
● Content protection

14. Why Flash?
Features missing in HTML5
● Content protection
○ RTMPE protocol / Flash Access

15. Why Flash?
Features missing in HTML5
● Content protection
○ RTMPE protocol / Flash Access
● Camera & Microphone Access

16. Why Flash?
Features missing in HTML5
● Content protection
○ RTMPE protocol / Flash Access
● Camera & Microphone Access
● Adaptive & Live Streaming

17. Why Flash?
Features missing in HTML5
● Content protection
○ RTMPE protocol / Flash Access
● Camera & Microphone Access
● Adaptive & Live Streaming
● Fullscreen video

18. Why Flash?
Features missing in HTML5
● Content protection
○ RTMPE protocol / Flash Access
● Camera & Microphone Access
● Adaptive & Live Streaming
● Fullscreen video
○ Hardware accelerated HD cat videos!
○ **API available in webkit and gecko

19. Why Flash?
Mozilla Fullscreen API
var elem = document.getElementById("my-element");
document.onmozfullscreenchange = function() {
// The fullscreen element:
// document.mozFullScreenElement;
console.log ("We went fullscreen!");
};
elem.mozRequestFullScreen();

20. Why Flash?
Features missing in HTML5
● Content protection
○ RTMPE protocol / Flash Access
● Camera & Microphone Access
● Adaptive & Live Streaming
● Fullscreen video
○ HD, hardware accelerated cat videos!
○ **API available in webkit and gecko

21. Why Flash?
Features missing in HTML5
● Content protection
○ RTMPE protocol / Flash Access
● Camera & Microphone Access
● Adaptive & Live Streaming
● Fullscreen video
○ HD, hardware accelerated cat videos!
○ **API available in webkit and gecko
● Consistent format support

22. Why Flash?
Features missing in HTML5
● Content protection
○ RTMPE protocol / Flash Access
● Camera & Microphone Access
● Adaptive & Live Streaming
● Fullscreen video
○ HD, hardware accelerated cat videos!
○ **API available in webkit and gecko
● Consistent format support
○ HTML5 needs to support both H.264 and WebM

23. Why Flash?
Features missing in HTML5
● Content protection
○ RTMPE protocol / Flash Access
● Camera & Microphone Access
● Adaptive & Live Streaming
● Fullscreen video
○ HD, hardware accelerated cat videos!
○ **API available in webkit and gecko
● Consistent format support
○ HTML5 needs to support both H.264 and WebM
● Cross platform consistency****

24. Why HTML5?
<video> Expectations
● Open source technology
○ Browser / Player / Codec

25. Why HTML5?
<video> Expectations
● Open source technology
○ Browser / Player / Codec
● Lower latency
○ No plug-in instantiation

26. Why HTML5?
<video> Expectations
● Open source technology
○ Browser / Player / Codec
● Lower latency
○ No plug-in instantiation
● Better performance and fidelity

27. Why HTML5?
<video> Expectations
● Open source technology
○ Browser / Player / Codec
● Lower latency
○ No plug-in instantiation
● Better performance and fidelity
● Accessibility

28. Why HTML5?
<video> Expectations
http://imgs.xkcd.com/comics/in_ur_reality.png

29. Why HTML5?
<video> Expectations
● Open source technology
○ Browser / Player / Codec
● Lower latency
○ No plug-in instantiation
● Better performance and fidelity
● Accessibility
○ User agents can have special video handling

30. Please put on your
3D Glasses

31. By jmettrauxhttp://www.flickr.com/photos/jmettraux/4959258811/

32. Why HTML5?
3D
● Flash
○ Build for graphics
○ Tools for easy video manipulation
■ HTML5 would require WebGL or
Canvas
● HTML5
○ Easy integration with browser and
devices
○ Open Standard
○ Allows for innovations by the browser
vendors as well as YouTube

33. Round 2: Device-ability
By dakinyhttp://www.flickr.com/photos/dakiny/4430765149/

34. Why HTML5?
HTML5 Capable Browsers (~60%)

35. Why HTML5?
Flash Support vs. HTML5 Support

36. Why HTML5?
YouTube Data API Usage for Flash vs. HTML5 Devices

37. Why HTML5?

38. When HTML5?

39. Primary Goal:
Recover playbacks that would
be lost without flash

40. Our Solution

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

42. When HTML5?
<iframe> Embed
● Give the user HTML5 or Flash based on device and user
preferences.
● Allows for better mobile support.
● Offers an "it just works" experience.

43. Why an iframe?
Other embedding methods
● <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

44. When HTML5?
When does the user get HTML5?

45. When HTML5?
Detecting HTML5
var videoElement = document.createElement('video');
if (videoElement && videoElement.canPlayType &&
(videoElement.canPlayType('video/mp4; codecs="avc1.42001E, mp4a.40.2"') ||
videoElement.canPlayType('video/webm; codecs="vp8.0, vorbis"'))) {
// Sweet, we can use HTML5!
}

46. When HTML5?
When does the user get HTML5?

47. Round 3: Performance
By Two Hawk's Eye
http://www.flickr.com/photos/mycoolpics/92033686/

48. Player Start Time
Flash
500ms
HTML5
(Up from 200ms in Jan 2011)
TODO(schechter): Add csi screen captures

49. iframe Embed Time Till Thumbnail Visible
Flash - 5.1s
HTML5 - 1.4s
*Collected data shows faster load times than this control
environment, but the comparison is actuate.

50. Get Video Time

51. Get Video Time
● HTML5:
○ Opera is Awesome
■ 200ms ahead of the pack
● Flash: IE9 and Opera are the leaders
○ 300ms faster
● HTML5 is almost always faster than Flash
○ 300ms - 400ms faster
○ IE9 is an exception
■ IE9 Flash is slightly faster than IE9 HTML5

52. Video Start Time
HTML5
Flash 2.5s

53. Video Start Time
HTML5
Flash 2.5s
● Firefox closest to catching Flash
○ HTML5 ~1.0s slower than Flash

54. So why is Flash so fast?

55. Make Assumptions

56. Making Assumptions
● Most users have a recent version of flash
● Thus we can optimistically embed the most
common case and do version checking and
updating after a script loads
● 250ms improvement to flash start time

57. Preload Video Connection

58. Preload Video Connection
● Resolves DNS while page is rendering
● Maintains an open connection
● 200ms improvement
<head>
<script>
var img = new Image();
img.src = videoConnectionUrl;
</script>
</head>

59. What about embeds?

60. #1 cache

61. 1. youtube.com/v/di5I49yg7bY 302 redirect
2. s.ytimg.com/swf/l.swf?args&swf=swf2-hash_url.swf
3. s.ytimg.com/swf/swf2-hash_url.swf ~150kb

62. 1. youtube.com/v/di5I49yg7bY 302
2. s.ytimg.com/swf/l.swf?args&swf=swf2-hash_url.swf
3. s.ytimg.com/swf/swf2-hash_url.swf
Better
1. youtube.com/v/di5I49yg7bY application/x-shockwave-flash
2. s.ytimg.com/swf/swf2-hash_url.swf

63. 1. youtube.com/v/di5I49yg7bY 302
2. s.ytimg.com/swf/l.swf?args&swf=swf2-hash_url.swf
3. s.ytimg.com/swf/swf2-hash_url.swf
1. youtube.com/v/di5I49yg7bY application/x-shockwave-flash
2. s.ytimg.com/swf/swf2-hash_url.swf
Best
1. youtube.com/embed/di5I49yg7bY text/html
2. s.ytimg.com/swf/swf2-hash_url.swf

64. #2 lazy load

65. Most embeds are never played.

66. ● Delay expensive queries.
● Use cache for most videos.
● Delay loading... flash?

67. Demo:
http://gregthebusker.com/iframedemo.html

68. Player API
http://code.google.com/apis/youtube/getting_started.html#player_apis

69. The JavaScript API
Communication

70. The JavaScript API
Communication
● Poll the URL fragment?
http://youtube.com/embed/video_id#fragment

71. The JavaScript API
Communication
● Poll the URL fragment?
http://youtube.com/embed/video_id#fragment
● Messages are one dimensional.
● Polling eats up CPU and is not instant.
● Both directions of communication use the same
fragment.

72. The JavaScript API
Communication
● Better idea: PostMessage API.
someWindow.postMessage(message, targetOrigin);

73. The JavaScript API
Communication
● Better idea: PostMessage API.
someWindow.postMessage(message, targetOrigin);
● Uses JSON for native encoding and decoding of data.
● No polling.
● Native event listeners.
● Communications are sandboxed per-window.
● Calls are asynchronous.

74. Conclusion
● Flash is still preferred in most places
○ More critical features
○ Deeper reach
● HTML5 is awesome
○ Improves every day
○ Greater mobile reach
○ People want it

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