Screencasting

Transcript

1. 1
   Screencasting
   Rex Tsai
   chihchun@kalug.linux.org.tw
   http://nutsfactory.net/
   H4 @ MR Brown
   2013-08-29
   (2013-09-01 updated)
   

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2. 2
   Screen mirroring solutions
   ●
   AirPlay
   ●
   mirroring standard for iOS.
   ●
   Miracast/WiDi
   ●
   RTP/RTSP
   ●
   Chromecast
   ●
   DIAL
   ●
   WebRTC
   

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3. 3
   Apple AirPlay
   ●
   Wireless Media Streaming / Screen Mirroring Protocol
   for iOS
   ●
   Discovery – Bonjour / zeroconf
   ●
   AirPlay service / RAOP (Remote Audio Output Protocol)
   ●
   FairPlay for protect screen content and encrypted
   ●
   UDP-based, based on RTSP
   ●
   Codec - Apple Lossless codec with 44100 Hz and 2 channels
   and H264
   ●
   Proprietary protocol, only license audio-streaming to 3rd
   partyies
   

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4. 4
   Requirement for hacks
   ●
   Understand FairPlay / DRM for screen
   protection
   ●
   FairPlay DRM initiation - ‘/fp-setup’
   ●
   Video steaming encryption
   ●
   AirTunes/AirPlay private/public RSA keys
   ●
   Implement the AirPlay receiver server
   

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5. 5
   Commerical products of
   AirPlay mirroring
   ●
   James Laird reverse-engineered and released the
   private key
   ●
   VMLite rPlay for Raspberry Pi and Windows
   – http://www.youtube.com/watch?v=aviPOINM6Bk
   ●
   Electroniccolor -
   http://v.youku.com/v_show/id_XNTgwMjQzMTk2.html
   AirParrot - http://www.airsquirrels.com/airparrot/
   ●
   AirServer - http://www.airserver.com/
   ●
   Hacksugar: Live AirPlay mirroring to Mac from iOS |
   TUAW - The Unofficial Apple Weblog
   – http://www.tuaw.com/2012/02/08/hacksugar-live-airplay-mirroring-to-mac/
   

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6. 6
   Micrast/Wireless Display
   ●
   Discovery - WiFi Direct (Layer 2 protocol)
   ●
   Media Protocol
   ●
   RTP
   ●
   RTSP
   ●
   Available
   ●
   Android 4.2
   ●
   Windows client available from Intel
   ●
   Built-in in Windows 8.1
   ●
   Wi-Fi Display Technical Specification 199USD
   

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11. 11
    AOSP Miracast Sink
    ●
    Android 4.2
    ●
    https://github.com/kensuke/How-to-Miracast-on-AOSP/wiki
    ●
    https://github.com/kensuke/
    ●
    Demo - http://www.youtube.com/watch?v=KNEmaIr3FEg
    ●
    Possible to port this feature to Android dongle like mk802
    

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12. 12
    Chromecast
    ●
    DIscovery And Launch http://www.dial-multiscreen.org/
    ●
    Based on UpnP & REST
    ●
    WebRTC http://www.webrtc.org/
    ●
    Support applications
    ●
    YouTube
    ●
    Netflix
    ●
    Google Play Music
    ●
    Google Play Movies & TV
    ●
    “Google Cast” Browser plugin available for Windows, Mac OS,
    Linux.
    https://chrome.google.com/webstore/detail/google-cast/boadgeojelhgndaghljhdicfkmllpafd
    ●
    Bootloader is hacked
    http://wiki.gtvhacker.com/index.php/Google_Chromecast#Bootloader_Exploit_Package
    ●
    Does not work in AP Isolation mode
    https://support.google.com/chromecast/answer/3213084?hl=en
    

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13. 13
    Supported Media Types
    ●
    Video codecs: H.264 High Profile Level
    4.1, 4.2 and 5, VP8
    ●
    Audio decoding: HE-AAC, LC-AAC,
    CELT/OPUS, MP3
    ●
    Containers: MP4/CENC, WebM,
    MPEG-DASH, SmoothStreaming
    ●
    Level 1 DRM support: Widevine,
    Playready
    https://developers.google.com/cast/supported_media_types
    

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16. 16
    Chromecast clone Software
    ●
    SINK (Server)
    ●
    CheapCast - https://github.com/mauimauer/cheapcast
    – Supported Applications
    ●
    ChromeCast
    ●
    YouTube
    ●
    PlayMovies
    ●
    GoogleMusic
    ●
    GoogleCastSampleApp
    ●
    GoogleCastPlayer
    ●
    Fling
    ●
    TicTacToe
    – Unstable, Android's WebView does not work well on old device like mk802.
    ●
    SOURCE (Clients)
    ●
    AirCast
    ●
    RemoteCast
    

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17. 17
    References
    ●
    Unofficial AirPlay Protocol Specification
    http://nto.github.io/AirPlay.html
    ●
    Wi-Fi Display Technical Specification v1.0.0
    http://www.wi-fi.org/knowledge-center/published-specifications
    ●
    Stream Laptop Content over HDTV with Intel® Wireless Display
    https://www-ssl.intel.com/content/www/us/en/architecture-and-technology/intel-wireless-display.html
    ●
    https://www.wi-fi.org/sites/default/files/uploads/wp_Miracast_Industry_20120919.pdf
    ●
    DIAL-2ndScreenProtocol-1.6.4.pdf http://www.dial-multiscreen.org/dial-protocol-specification
    ●
    Google Cast API https://developers.google.com/cast/
    

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