HTML5 Video Hardware Acceleration

MeeGo TV Hardware Capability

• Video Display Controller Architecture

Image(vdc.PNG)

• 4-5 Universal Pixel Plane for graphics and video rendering
• Hardware blender supports IAP and ARGB pixel format UPP
• Two hardware decoders - H.264, VC1, MPEG2. support 2-way 1080p video decoding
• Hardware Scaler
• PVR SGX Graphics Core

Multi-plane Solution

Image(mp-solution.PNG)

• Render Process:
  • Replace the FFMPEG based !WebMediaPlayer with UMMS based !UmmsWebMediaPlayer
  • Webkit calculates video destination area and transparent area.
• Browser Process:
  • DBus bridge in browser to adapt security sandbox
  • Issue plane level transparency commands
• Unified Multimedia Service
  • The actual playback engine
  • Playback and media control
  • DBus interface
  • Multi-session support
  • Multi media engines(Gstreamer, !OpenMax…)
• mutter-meego-tv: Handle hints for transparency
  • Facts:
    • Browser rendered on X window
    • X rendered on above plane,
    • Hardware accelerated video is rendered on underneath plane.
    • X server does not handle alpha channel by default
    • Alpha channel is used in plane level with Pixel format ARGB
  • Solution: Windows manager handles the alpha channel when compositing
  • Result: See through the right area of X to show video

Video As Texture

Image(vat-solution.PNG)

• Render & Browser processes co work to redirect playback commands to UMMS
• UMMS is responsible for hardware accelerated video decoding and color conversion.
• RGBA data is shared between UMMS and render process
• Render process renders the texture to the video area.

Tradeoff

• Multi-plane
  • Pursues maximized performance
  • Depend on wm, currently only mutter is enhanced.
  • Video/browser display memory separated, advanced feature not available
• Video as Texture
  • Keep the integrity of the browser window’s display memory, which enables a lot of advanced HTML5 features.
  • Involve color conversion and memory copy that can be expensive for HD videos