Enabling Media Playback On Windows 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 Increasing Stability and Performance

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 signatures as 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 Drivers Filter Graph Filter Graph WM Player ActiveX Control WMP Sample App, IE 6 DirectDraw/GDI WaveDev WaveDev Hardware Network/ File System Source Codecs DirectShow Filter Graph Manager DVD- Video D3DM Renderers DirectShow App D3D Mobile, DVD, DDraw Apps DDraw Apps WMV WMA MPE G

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/ embedded microsoft.public. windowsxp.embedded windowsce.platbuilder windowsce.platbuilder windowsce.embedded.vc windowsce.embedded.vc blogs.msdn.com/ mikehall Windows CE 5.0 Eval Kit Windows XP Embedded Eval Kit msdn.microsoft.com/ mobility microsoft.public. pocketpc.developer smartphone.developer dotnet.framework.compactframework blogs.msdn.com/ windowsmobile vsdteam netcfteam Windows Mobile 5.0 Eval Kit Websites Newsgroups Blogs Tools Build Develop

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