HTML5 VIDEO (Smooth Streaming) on Chromecast について調べてみた

1. HTML5 VIDEO
on Chromecast
HTML5 VIDEO(Smooth Streaming) について調べてみた

2. About me
Katsumi Onishi
(@KatzMii)
Android Developer
HTML5 Beginner
動画配信サービスでMicrosoft Smooth StreamingのChromecast対応の調査中

3. Chromecast
• 2013/7 Googleから発売されたドングルデバイス
• TV接続するHDMIスティック
• Android/iPhone/iPad/PCから、動画・音楽をテ
レビ画面で再生することが出来る。

4. 対応しているサービス
• Google Play (Movie/Music)
• YouTube
• Netflix
• Hulu
• Pandora

5. Supported Media Types
Video
Audio
Container
H.264 High Profile Level 4.1, 4.2 and
5, VP8
HE-AAC, LC-AAC, CELT/Opus, MP3,
Vorbis
MP4/CENC, WebM, MPEG-DASH,
SmoothStreaming
非対応:HTTP Live Streaming
DRM
Widevine, PlayReady
Subtitle
TTML - Timed Text Markup Language
WebVTT - Web Video Text Tracks

6. Casting Your Content to the Big Screen
Sender
Receiver

7. Sender and Receiver
sender
application
Sender
DIAL
Receiver
Discovery
Launch
receiver
application
running
(HTML5)
Connection
RAMP
WebSocket
LoadMedia
Play/Pause/Volume/Muted
status
DIAL - UPnPに定義されているSSDPに基づいたディスカバー&ランチのプロトコル - http://www.dial-multiscreen.org/
RAMP - GoogleCast用のメッセージ送受信プロトコル (on WebSocket) - https://github.com/dz0ny/leapcast/wiki/RAMP-protocol

8. First Sample Application Build and Launch
Sender(Android)はライブラリを色々設定しなければな
らないので少し手間が掛かるが、
Receiver(HTML5)は、HTMLファイル１つだけ
MP4は簡単に再生!
https://github.com/googlecast/cast-android-sample

9. Sender Application
~ 省略 ~

10. Receiver Application
1.Receiver
2.RAMP
3.Channel
4.bind <video>

11. Google Cast Receiver API
•
•
•
•
•
•
•
•
•
cast.receiver.Channel
cast.receiver.ChannelFactory
cast.receiver.ChannelFactoryEvent
cast.receiver.ChannelHandler
cast.receiver.ConnectionService
cast.receiver.MessageEvent
cast.receiver.Platform
cast.receiver.Receiver
cast.receiver.RemoteMedia

12. Google Cast Receiver API
•
•
•
•
•
•
•
•
•
cast.receiver.Channel
cast.receiver.ChannelFactory
cast.receiver.ChannelFactoryEvent
cast.receiver.ChannelHandler
cast.receiver.ConnectionService
cast.receiver.MessageEvent
cast.receiver.Platform
cast.receiver.Receiver
cast.receiver.RemoteMedia
これだけ？

13. Google Cast Receiver API
•
•
•
•
•
•
•
•
•
cast.receiver.Channel
cast.receiver.ChannelFactory
cast.receiver.ChannelFactoryEvent
cast.receiver.ChannelHandler
cast.receiver.ConnectionService
cast.receiver.MessageEvent
cast.receiver.Platform
cast.receiver.Receiver
cast.receiver.RemoteMedia
これだけ？
通信系ばかり

14. Google Cast Receiver API
•
•
•
•
•
•
•
•
•
cast.receiver.Channel
これだけ？
cast.receiver.ChannelFactory
cast.receiver.ChannelFactoryEvent
cast.receiver.ChannelHandler
cast.receiver.ConnectionService
cast.receiver.MessageEvent
通信系ばかり
cast.receiver.Platform
cast.receiver.Receiver
cast.receiver.RemoteMedia
Adaptive
は？

15. Google Cast Receiver API
•
•
•
•
•
•
•
•
•
cast.receiver.Channel
これだけ？
cast.receiver.ChannelFactory
cast.receiver.ChannelFactoryEvent
cast.receiver.ChannelHandler
cast.receiver.ConnectionService
cast.receiver.MessageEvent
通信系ばかり
cast.receiver.Platform
cast.receiver.Receiver
cast.receiver.RemoteMedia
Adaptive
は？
DRMは？

16. Support or Group ....

17. Google Goolge Google

18. Google Goolge Google
EME

19. Google Goolge Google
EME
CDM

20. Google Goolge Google
EME
CDM
MSE

21. Google Goolge Google
EME
CDM
WTF
MSE

22. Google Goolge Google
EME
CDM
MSE
WTF
Google, Microsoft and Netflix in W3C

23. Extends HTMLMediaElement
• Media Source Extensions (MSE)
• アダプティブ ストリーミングのサポートの定義
• Encrypted Media Extensions (EME)
• コンテンツ保護システムをサポートするため定義
• CDMへアクセスする為のAPI定義
• Content Decryption Model (CDM)
• コンテンツ暗号解除モジュール
• 実装はプラットフォーム側

24. Encrypted Media Extensions - W3C

25. dash.js
• dash.js • MPEG-DASHの Media Source Extensions API の
http://dashif.org/reference/players/javascript/index.html
JavaScript ライブラリ
•
Microsoft Smooth Streaming 対応?
• MPEG-DASH(Dynamic Adaptive Streaming over
HTTP)
• HTTPプロトコルを使った動画配信プロトコルの国
際標準規格
http://dashif.org/

26. Receiver Application
1.Receiver
2.Custom MessageStream
3.Channel

27. 2.Custom MessageStream
Message 処理
Event Bind

28. Format?
Format
URL strings
MPEG DASH
/Manifest(format=mpd-time-csf)
(live profile)
Smooth
Streaming
/Manifest
OK
NG
Windows Azure Media Services 側で対応が必要？

29. DRM - EME/CDM
Developer Programs
Engineer for Chromecast

30. DRM - EME/CDM
スクラッチ!?
Developer Programs
Engineer for Chromecast

31. 中間 まとめ
• Chromecast(HTML5)上でアダプティブ ストリーミン
グをするには、dash.jsを使用する必要がある。
• MPEG-DASHがSmooth Streaming包括してるのか調
査が必要
• EMEはサポートされているので、CDMを使用して復
号化の仕組みは作れるぽい。スクラッチでね♥

32. つづく...!!

33. 参考
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Casting Your Content to the Big Screen - Google Cast — Google Developers https://developers.google.com/
cast/
Stack Overflow http://stackoverflow.com/questions/tagged/chromecast
Stack Overflow http://stackoverflow.com/questions/tagged/google-cast
EME・DRMの行方 - http://furoshiki.hatenadiary.jp/entry/2013/06/07/040209
HTML5でDRMってアリなの？ - https://www.slideshare.net/otachan/html5drm
DRM in HTML5 - https://luv.asn.au/files/20130604-drm_in_html.pdf
DRM in HTML5 | The Beautiful, Tormented Machine http://manu.sporny.org/2013/drm-in-html5/
EME WTF?: An introduction to Encrypted Media Extensions - HTML5 Rocks http://www.html5rocks.com/en/
tutorials/eme/basics/
Microsoft PlayReady DRM を使った Web ブラウザーでの Encrypted Media Extensions のサポート (Windows)
http://msdn.microsoft.com/ja-jp/library/windows/apps/dn466732.aspx
The Netflix Tech Blog: HTML5 Video at Netflix http://techblog.netflix.com/2013/04/html5-video-at-netflix.html
MPEG-DASH http://dashif.org/
DASH-264 JavaScript Reference Client Landing Page http://dashif.org/reference/players/javascript/
index.html
Dash-Industry-Forum/dash.js Wiki https://github.com/Dash-Industry-Forum/dash.js/wiki
Media Source Extensions http://www.w3.org/TR/media-source/
Encrypted Media Extensions http://www.w3.org/TR/encrypted-media/