EnablingEnablingMedia Playback On Media Playback On Windows CE 5.0Windows CE 5.0

Li-Ming Fan

Escalation Engineer

Microsoft GCR GTSC

Agenda

• Multimedia Overview and Architecture

• Windows Media Playback Pipeline– Streaming features on CE 5.0

CE Multimedia Goals• Provide a rich set of multimedia

technologies that enable customers to rapidly build a variety of consumer devices– Small, Fast, Hardware Assisted– Compatibility with desktop Windows

when possible– Optimized support for multiple CPUs and

Systems on Chip

Current MM Technologies• CE v5.0

– Windows Media v9 improvements/new codecs– Direct3D Mobile

• CE v4.2– Windows Media v9

• CE v 4.0 – Windows Media Player Application– Windows Media v8– DVD

• CE v 3.0– DirectShow, DirectDraw– Windows Media Player OCX v6.4

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Windows CE Multimedia• Technologies

– Audio– Video– 2D and 3D Graphics– Codecs – Streaming– DVD-Video– Digital Rights

Management

• Products– MSTV– MSNTV– Windows for

Automotive– Portable Media Center– SmartPhone– PocketPC– VOIP Phone– IP Set-Top-Box– PVR– DMR

Technology Breakdown• DirectDraw

– Drawing surfaces, blting, flipping, overlays, alpha blend, video ports

• Direct3D Mobile– 3D polygon rendering– Direct3D Mobile uses

the same API signaturesas Direct3D

– Lightweight, integer based• Waveform Audio

– Playback, capture, mixing, sample rate conversion, gain classes

• DirectShow– Media playback

• DVD-Video– DVD navigation

and playback– DVD Player app

• Windows Media – Audio/video codecs– Streaming/Local File– WM Player OCX– WM Player app

Windows Media Components

• Streaming– HTTP, MMS, local file

• ASX play list parser and handler

• ASF parser and splitter• DRM/decryption

• Software Codecs– WMV 9 Advanced

Profile (new in 5.0)– WMV – WMA– WMA lossless

(new in 5.0)– WMA Pro

(new in 5.0)

• DirectShow standard renderer filters

CE Multimedia Architecture

Network, File system, Graphics, Audio, DVD DriversNetwork, File system, Graphics, Audio, DVD Drivers

Filter GraphFilter Graph

WM Player ActiveX WM Player ActiveX ControlControl

WMP Sample App,WMP Sample App,IE 6IE 6

DirectDraw/GDIDirectDraw/GDI WaveDevWaveDev

Hardware

Network/Network/File SystemFile System

SourceSource CodecsCodecs

DirectShow Filter Graph ManagerDirectShow Filter Graph Manager

DVD-DVD-VideoVideo

D3DMD3DM

RenderersRenderers

DirectShow DirectShow AppApp

D3D Mobile, DVD,D3D Mobile, DVD, DDraw AppsDDraw Apps

WMVWMV

WMAWMA

MPEMPEGG

Encoding For Local Playback

• Variable bit rate is good for conserving disk space

• CE 5.0 supports high content bit rates• Make sure indexing is turned on

– The playback pipeline uses the index to rapidly seek for trick modes

– Trick mode performance is degraded without an index

New Streaming Features• FastStart

– Enables stream to buffer at speeds higher than the bit rate of the requested content

– Buffer fill rate governed by bandwidth of the pipe and limits set on the Windows Media server

– Supported for live broadcast and on demand– Only supported on unicast streams

• Startup profile– Improves stream start time over FastStart– Important for IPTV channel change latency– Only for the HTTP unicast protocol

How Startup Profile Works• Windows CE will look at the content and calculates an

acceleration duration based on the content preroll, bit rate, and the FSAccBandwitdth

• The Windows Media Server (WMS) uses this acceleration duration value as the length of time to scan the content for the startup buffering requirements

• WMS then determines a minimal buffer (essentially a preroll) that the client decoder requires to play the acceleration duration without starving the decoder

Streaming Protocols• Multicast

– Each packet is broadcast to multiple clients

• Microsoft Media Stream (MMS)– TCP connection for commands between client and server– UDP connection for commands between client and server– Automatic protocol roll-over (UDP, TCP)

• HTTP– Will automatically come through corporate firewalls– Will use Internet Explorer’s proxy-settings, or configure its own

settings

• RTSP– Not supported on Windows CE

• File-based (local or network redirector)

Protocol Comparison On CE

• MMS is good for up to 2Mb/s– No fast start and startup profile– Lighter network load (no ack’s)– Requires more reliable hardware and well dimensioned

networks– MMS is getting deprecated in servers in favor of RTSP

and HTTP

• HTTP is better at high bit rates – internally tested up to 10Mb/s on CE 5.0– Fast start and startup profile

Encoding For Streaming• Preroll

– We use 5 seconds for HTTP unicast– MMS as low as 1 second for a quiet network

• No startup profile

– Multicast as low as 1 second for a quiet network• No fast start and startup profile

• Bit rate – Highest for your pipe

• Key frame distance– 5 seconds for HTTP/MMS unicast– 1 second for Multicast (faster startup)

Tools & Resources

msdn.microsoft.com/msdn.microsoft.com/ embeddedembedded

microsoft.public.microsoft.public. windowsxp.embeddedwindowsxp.embedded windowsce.platbuilderwindowsce.platbuilder windowsce.embedded.vcwindowsce.embedded.vc

blogs.msdn.com/blogs.msdn.com/ mikehallmikehall

Windows CE 5.0 Eval KitWindows CE 5.0 Eval KitWindows XP Embedded Eval KitWindows XP Embedded Eval Kit

msdn.microsoft.com/msdn.microsoft.com/ mobilitymobility

microsoft.public.microsoft.public. pocketpc.developer pocketpc.developer smartphone.developer smartphone.developer dotnet.framework.compactframeworkdotnet.framework.compactframework

blogs.msdn.com/blogs.msdn.com/ windowsmobilewindowsmobile vsdteamvsdteam netcfteamnetcfteam

Windows Mobile 5.0 Eval KitWindows Mobile 5.0 Eval Kit

WebsitesWebsites

NewsgroupsNewsgroups

BlogsBlogs

ToolsTools

BuildBuild DevelopDevelop

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