9/21/2016
`
`Multimedia Streaming on Microsoft Windows CE 3.0
`
`Multimedia Streaming on Microsoft Windows
`CE 3.0
`
`Windows CE 3.0
`
`Microsoft Corporation
`
`June 2000
`
`Summary: This paper discusses the multimedia streaming capabilities using Windows Media™ components included in
`Microsoft® Windows® CE DirectX Platform Adaptation Kit 1.2 ﴾or DXPAK﴿, and its differences from other versions of Microsoft
`Windows. ﴾14 printed pages﴿
`
`Contents
`Overview
`Technical Fundamentals
`Windows Media Player Control
`Windows Media Technologies
`Windows Media Formats
`Windows Media Features
`Windows Media Protocols
`Windows Media Codecs
`DirectShow
`Filter Graph Manager
`Filters
`For More Information
`
`Overview
`The digital revolution has taken the consumer electronics space by storm. Digital cable set top boxes offering hundreds of
`channels are quickly replacing older, analog cable boxes. Portable digital audio players offer multiple hours of music playback at
`a much higher sound quality and fraction of the size of a portable tape player. The overall change in consumer electronics
`devices from analog to digital is both a radically new phenomenon and a natural evolution. Because of this evolution, it is now
`generally accepted that the PC will no longer be the only source for digital multimedia.
`
`Many of these new consumer devices entertain consumers by playing digital music, movies, TV, or other multimedia content. The
`amount of data needed to store digital content, even when compressed using the best available coding algorithms such as
`Microsoft Windows Media™ Audio, is very large. For example, when compressed at 120 Kbits/sec, digital audio requires 3.6 MB
`to store a four‐minute song, while to store a two‐hour movie, digital video at 300 Kbits/sec uses 270 MB, and at 4 Mbits/sec
`would require 3.6 GB!
`
`Large media files can be managed by either:
`
`Downloading the entire file into local memory and then processing a sequence of stored data blocks ﴾local streaming﴿ or
`processing the entire stored file ﴾non‐streaming﴿
`—or—
`Downloading and processing a sequence of individual data blocks ﴾network streaming﴿.
`
`Network streaming can also be used for processing media data created on the server in real‐time and never stored as a single
`file.
`
`https://msdn.microsoft.com/en­us/library/ms834433.aspx
`
`1/10
`
`Petitioner Alarm.com's Exhibit 1026
`1026.0001
`
`Alarm.com. v. Vivint
`IPR2015-01977
`
`

`
`9/21/2016
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`Multimedia Streaming on Microsoft Windows CE 3.0
`
`Sending the next relatively small amount of data needed for immediate processing and playback ﴾and not the complete data set﴿
`works because multimedia content is a series of digital data without strong long‐term temporal coupling. In other words, a block
`of sound values in a song or pixels in a video frame can be processed and displayed independently, at least when they are
`separated by sufficient time. This allows a stream of multimedia data to be broken up into temporal groups of independent data.
`These data are then encoded, transmitted, and played back in temporal order independently of either proceeding or succeeding
`group of data that will be displayed at different times. This method of sending blocks of time‐ordered, temporally decoupled
`data to the client device is called streaming. The client device needs only to buffer enough packets of data to allow for server,
`network, or client side interruptions or irregularities in the creation, transmission, and time correct display of the streamed data.
`
`How does Windows CE fit into this picture? By providing Windows Media components, Windows CE DirectX Platform Adaptation
`Kit 1.2 ﴾or DXPAK﴿ enables many of the rich multimedia playback and streaming capabilities found on PCs, but does so with
`smaller, more configurable components. These components run on many of the high‐performance CPUs supported by Windows
`CE ﴾x86, MIPS R4300 and compatible, and SH4, available now with DXPAK 1.1; ARM, StrongARM, and integer MIPS planned for
`DXPAK 1.2﴿. In addition, the modularity of Windows Media components for Windows CE gives you flexibility in choosing which
`components your platform uses. When building an operating system image for your hardware using Platform Builder, you can
`decide whether you want a particular DirectX or user interface component, communications protocol, or file system. This kind of
`flexibility allows you to ship only those technologies you are actually using on your platform, saving space and reducing
`complexity.
`
`Windows CE 3.0 with the DirectX Platform Adaptation Kit 1.2 ﴾or DXPAK﴿ provide a complete solution for developing the next
`“killer” consumer appliance or application. It is a robust, powerful real‐time operating system that now provides a rich set of
`components for enabling digital multimedia devices.
`
`Technical Fundamentals
`The Microsoft DirectShow® portion of Microsoft DirectX® provides the foundation for all multimedia services on Windows CE. It
`is possible provide a rich multimedia application using solely DirectShow, and in fact many companies are doing just that, but it
`is not the only way to proceed. A communication structure has been built on top of DirectShow to make the application
`developer's job easier. How everything fits together is illustrated in the following diagram:
`
`Figure 1. Communication structure based on DirectShow
`
`https://msdn.microsoft.com/en­us/library/ms834433.aspx
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`2/10
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`Petitioner Alarm.com's Exhibit 1026
`1026.0002
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`

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`Multimedia Streaming on Microsoft Windows CE 3.0
`9/21/2016
`The user sees the top layer of this diagram: the web browser or other application. The application either has the Window Media
`Player ﴾WMP﴿ control embedded within it, or communicates via COM with the DirectShow interfaces. In either case, DirectShow
`manages the flow of data from the source to the hardware. The application developer is most concerned with the second and
`third layers of information flow. The driver developer is most concerned with the bottom layers. What follows is a look at the
`sections the application developer needs to understand: the WMP control, WMT, and DirectShow.
`
`Windows Media Player Control
`Recognizing the importance of multimedia to web content, Microsoft created the Windows Media Player ﴾WMP﴿ control. This
`technology enables the Windows Media Player to exist as a Microsoft ActiveX control inside a web page along with other
`content. The WMP control is a versatile tool for presenting local and streaming multimedia files. It supports playback of nearly all
`major media file formats, including Windows Media format files ﴾ASF, ASX, WMA, WMX, WMV, WVX, WM, and WMX files﴿,
`Motion Pictures Experts Group formats ﴾MPG and MPE files﴿, and audio formats such as MP3, MIDI, WAV, and AIFF, and
`multimedia format AVI files. All these file formats can be streamed from locally stored files using just the WMP control, and,
`when combined with the Microsoft Windows Media Technologies, streaming over networks is supported. DirectX Platform
`Adaptation Kit 1.2 ﴾or DXPAK﴿ supports the Windows Media Player 6.4 version of the controls.
`
`Placing the WMP Control in a Web Page
`The OBJECT tag is used to embed ActiveX objects into a Web page. The following example shows how to use the OBJECT tag to
`insert the Windows Media Player ﴾WMP﴿ control.
`
`<OBJECT ID="MediaPlayer"
`  CLASSID="CLSID:22d6f312‐b0f6‐11d0‐94ab‐0080c74c7e95"
`  TYPE="application/x‐oleobject"
`  WIDTH="320"
`  HEIGHT="240"
`  STYLE="position:absolute;
`      left:50px;
`      top:50px;"
`
`><
`
`PARAM NAME="FileName" 
`               VALUE="http://example.microsoft.com/media/sample.asf">
`  <PARAM NAME="ShowControls" VALUE="1">
`  <PARAM NAME="ShowStatusBar" VALUE="1">
`  
`</OBJECT>
`
`The ID attribute of the OBJECT tag specifies a name for the WMP object, for later use in scripting. The CLASSID attribute is
`required for Internet Explorer to create the object on the page, and should always be the string listed in the preceding example.
`The TYPE attribute indicates to the browser that the type of embedded OBJECT is an ActiveX object. The optional WIDTH and
`HEIGHT parameters set the size of the window used for the WMP object. The STYLE parameters enable you to position the
`object window anywhere on the Web page.
`
`All WMP functionality is exposed to the Microsoft JScript web scripting language. There is currently no support for any other
`scripting language.
`
`Note that the CODEBASE attribute is conspicuously absent from the OBJECT tag. The CODEBASE attribute contains a Uniform
`Resource Locator ﴾URL﴿ pointing to a location where the WMP control can be downloaded if it is unavailable on a user's system.
`This functionality is not supported on Windows CE. The WMP control for Windows CE must be included in your OS image if it is
`going to be used by your application.
`
`https://msdn.microsoft.com/en­us/library/ms834433.aspx
`
`3/10
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`Petitioner Alarm.com's Exhibit 1026
`1026.0003
`
`

`
`Multimedia Streaming on Microsoft Windows CE 3.0
`9/21/2016
`The PARAM tags have two attributes: The first is the name of the property being set, and the second specifies the value of that
`property. The PARAM tags initialize the WMP object with specified data when it is created. In this example, the first PARAM tag
`sets the FileName property to the URL http://example.microsoft.com/media/sample.asx, defining which file the WMP control will
`play. The value could also be a path to a local media file, such as C:\sample.asx. The remaining PARAM tags specify that the
`playback controls and status bar should both be visible for this object. Any of these elements could be hidden instead, enabling
`you to customize the appearance of the WMP control and user interface items.
`
`After you have created the object and specified a valid file name, you should see the WMP control on your Web page.
`
`There are three other HTML tags that are used to include audio and video in Web pages—the embed object tag <EMBED>, the
`image tag <IMG>, and the anchor tag <A>. The <EMBED> tag was created by Netscape to support browser plug‐ins. Netscape
`does not support embedding objects with the <OBJECT> tag, so this tag should be used if you are trying to maintain
`compatibility with Netscape browsers. Although the <IMG> tag can be used to include video clips in a Web page, its use is
`limited to certain media types ﴾MPEG, QT, and AVI files.﴿ The <IMG> tag does not provide access to any of the WMP control
`parameters and does not work at all with audio media. In order to use the full functionality of the WMP control, the use of the
`<IMG> tag is not recommended.
`
`The <A> tag can also be used to create links to media. Media is played either by a helper application determined by the media
`type or the browser. The <A> tag cannot be used to embed media in a Web page as with the <OBJECT> or <EMBED> tags.
`One key point to keep in mind is that the WMP control is distinct from the Windows Media Player application. As a result, not all
`Internet media content can be handled by the WMP control. An example of this is content accessed with the <A> tag. Normally,
`when a user is browsing the Internet with a PC and clicks on a link to play a media file, the Windows Media Player application
`appears on the desktop and control over the media content is passed from the browser to it. If you are trying to build a device or
`application that supports all existing Internet media content, you must make sure the control recognizes and correctly handles all
`the different ways to deliver content over the Internet. The WMPHLPR sample included with DXPAK 1.2 provides an example of
`how to enable the WMP control to playback media accessed via the <A> tag. Using this sample, when a user clicks on a media
`file link, the browser navigates to a page that hosts the control. The media file is passed to the control and playback begins from
`within the browser. This behavior is quite useful for set‐top boxes, Internet portal devices, or any other device with either limited
`memory or a desire to run completely within a single window.
`
`The Windows Media Player control for Windows CE contains a few differences from the version of the control that is available for
`x86‐based PCs. The driving force behind including just a subset of the desktop WMP control's features is to provide a smaller,
`robust control that encapsulates the key features of the WMP control required by embedded devices. In addition, the WMP
`control for Windows CE also supports a subset of the properties, methods, and events from the desktop control. Some of these
`properties, methods, and events have not been included in the CE version of the WMP control, as they have no practical value
`for non‐PC devices such as set‐top boxes and audio jukeboxes. There is no support for backward compatibility with the
`Microsoft NetShow® player control, since all of the NetShow functionality has been encapsulated in the WMP control. Certain UI
`elements such as the context menu, Display panel, Closed Captioning panel, and Go To Bar are not supported, but can be
`authored for a Web page with scripting.
`
`The Microsoft PowerPoint® ﴾PPT﴿ streaming or hotspots ASF authoring features are not supported. With URL flipping, it is still
`possible to have the WMP control playing media in one frame while displaying slides or other graphics in another frame.
`Clickable hotspots can turn images or video clips into hyperlinks or script locations, and can also be implemented with the
`proper usage of URL scripting commands embedded at certain times in an ASF file.
`
`Windows Media Technologies
`Window Media Technologies ﴾WMT﴿ is a set of COM interfaces and codecs that support a broad range of server and client
`applications that stream audio, video, and script commands as a continuous flow of data.
`
`Today, Windows CE 3.0 with the DirectX Platform Adaptation Kit 1.2 ﴾or DXPAK﴿ provides Windows Media Technologies version
`4.1 components. These components support client playback using advanced Windows Media formats and world‐class codecs,
`such as Windows Media Audio, Microsoft MPEG‐4 video, and Sipro ACELP.net low bit‐rate speech.
`
`https://msdn.microsoft.com/en­us/library/ms834433.aspx
`
`4/10
`
`Petitioner Alarm.com's Exhibit 1026
`1026.0004
`
`

`
`Multimedia Streaming on Microsoft Windows CE 3.0
`9/21/2016
`What follows is a look at the formats, features, protocols, and codecs supported by WMT on Windows CE. Occasionally, the
`Windows CE implementation of WMT differs from other versions of Windows. When this is the case, the differences and their
`workarounds are discussed.
`
`Windows Media Formats
`To store and stream data, WMT uses the Advanced Streaming Format ﴾ASF﴿. ASF is an application‐level multimedia transmission
`file format ﴾as opposed to a wire or transmission control format﴿ for arranging and organizing synchronized multimedia data.
`ASF supports media data delivery over a wide variety of networks, network bandwidths, and protocols. It is optimized for
`streaming multimedia packets over both low bit‐rate and broadband networks.
`
`Windows CE also supports the Advanced Stream Redirector v3 ﴾ASX﴿ and Windows Media Station ﴾NSC﴿ metafiles. The ASX
`metafile provides mechanisms by which a client can support hyperlinks to streams, support specification of multiple pieces of
`source content, and the protocol rollover rules the client will use to process them, as well as support for media playlists.
`
`The Microsoft Windows Media Station metafile serves to describe a particular channel to an ASF client wishing to access that
`channel. The model for access to a channel is similar to a television accessing a broadcast channel. This metafile is used for
`multicasting support.
`
`Windows Media Features
`Windows CE provides WMT client DirectShow filters that allow playback of ASF streams sent using UDP, TCP, and HTTP protocols
`﴾as described in the next section, Windows Media Protocols. Windows CE WMT supports smart streaming using a multi‐data rate
`encoded ASF file, where multiple streams with different bit rates are created in one ASF file and the client negotiates with the
`server for the appropriate stream. The server then automatically adjusts the stream depending on playback conditions and can
`select from multiple video streams based on available network bandwidth.
`
`With smart streaming, the Windows CE WMT client can dynamically thin the stream based on the available bandwidth using an
`algorithm that adjusts delivery smoothly from full frames down to key‐frame only. If necessary, the WMT client can ask the server
`to send only audio and no video packets. As bandwidth is reduced, audio is always given the highest priority, since it is usually
`critical to the user experience. As network bandwidth conditions improve, WMT can progressively step the video bit‐rate back up
`to restore the viewing to an optimal level. In addition, the WMT UDP resend capability allows the client, if time is available, to
`request missing packets from the server. Finally, WMT also provides ASX event‐driven stream switching where the client sends
`ASX control commands to the server.
`
`Windows CE WMT does not support older ASX v2.0 or v1.0 formats. All of the functionality of these earlier versions has been
`encapsulated into ASX v3.0. In addition, the PREVIEWDURATION, BANNER, or LOGO ASX elements are not supported for
`Windows CE. Preview mode can be implemented within an application using the WMP control by providing access to playback
`control via scripting. The functionality of the BANNER and LOGO elements can be implemented using DHTML and scripting.
`
`Windows Media Technologies for Windows CE provides support for Authentication. Authentication involves user validation
`before any information exchange takes place. When a client initiates a request to the server that has authentication enabled, the
`server challenges the client to confirm its identity. Typically, this amounts to inspecting the name and password of the user
`account under various authentication protocols. For any given interaction, both client and server must adhere to one agreed
`protocol. The WMT supports the following two protocols, HTTP‐Basic for Internet applications and NTLM which is suitable for
`Intranet applications.
`
`On the desktop NTLM uses authentication information established when the user logs on, it requires the client and server to be
`on the same or trusted domains. Since Windows CE does not allow a user to log in, the WMT pops up a dialog box to extract the
`authentication information when NTLM authentication is required.
`
`Windows Media Protocols
`The following protocols are supported by the WMT: multicasting, local file streaming, HTTP streaming, and MMS streaming.
`
`https://msdn.microsoft.com/en­us/library/ms834433.aspx
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`5/10
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`Petitioner Alarm.com's Exhibit 1026
`1026.0005
`
`

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`Multimedia Streaming on Microsoft Windows CE 3.0
`9/21/2016
`Multicast enables the client to receive multicast streams. It allows the administrator to send one copy of the content to many
`users on the network, as long as that network is multicast‐enabled. IP Multicast streaming is done through ASF with the
`Microsoft Windows Media Station Metafile. Networks that are not multicast‐enabled and ASF files not being streamed from a
`Windows Media server are sent through unicast. Unicast means that one stream is sent for every request.
`
`WMT can provide local file streaming for systems with persistent storage. Data is read from persistent storage into a buffer in
`main memory and rendered. Local file streaming provides lower latency and a significant physical memory savings over reading
`the entire ASF file from the persistent store into main physical memory before rendering the file.
`
`MMS is Microsoft's proprietary protocol for streaming media. A typical MMS session uses a TCP connection for sending and
`receiving media control commands, and a UDP or TCP connection for streaming the data. Invoking the MMS protocol using
`mms:// invokes the protocol rollover mechanism. The client first tries to receive the stream through UDP. If UDP does not work,
`the stream automatically rolls over to TCP transmission. Finally, if TCP does not work, the client will try to receive the stream
`through HTTP. MMSU enables the client to receive streams through UDP. It is well suited to audio because it sends packets
`regardless of connection quality. Therefore, users hear fewer delays or pauses. If time allows, missed packets are requested and
`resent. MMST enables the client to receive streams through TCP. TCP forms a reliable stream—if packets are lost, the stream
`stops and lost packets are recovered. Users experience more delays and pauses over a network that is congested when using
`MMST.
`
`A regular HTTP server can be used to deliver ASF data streams, but there are several reasons to use the Windows Media Server
`instead. The packets within an ASF data stream must be delivered sequentially, one per network packet, for the full benefit of
`data streaming to be realized. Only an ASF‐compatible server, such as Windows Media Server, will avoid fragmentation by
`transmitting ASF packets one at a time, encapsulated neatly within individual Internet or other network protocol packets. The
`error correction, streaming playback, and bit‐rate optimization inherent to ASF depend on the client and server not having to
`figure out where ASF data packets begin and end on the fly. An HTTP server doesn't have this ability because it doesn't
`recognize the significance of ASF packets; it just shoves data to the client as quickly as possible by filling each network packet
`with an arbitrary amount of data. Additionally, several features of Windows Media, such as the ability to fast‐forward or rewind
`ASF data streams, are not available on a regular Web server.
`
`Windows Media Codecs
`The following table lists the supported codecs that can be contained within an ASF file. Windows CE WMT will only support
`content that is created with the Windows Media Tools. The Windows Media Encoder uses templates to encode live source or AVI,
`WAV, or MP3 content into ASF formats with the codecs listed in the table below. The templates also provide the option of using
`other codecs, but DirectShow for Windows CE only supports WMT codecs. While other codecs that are supported by DirectShow
`for Windows CE ﴾such as Cinepak or MPEG‐1﴿ can be created within an ASF file using other authoring tools, there can be no
`guarantee as to their streaming performance, and their use is not recommended.
`
`Codec name
`
`MPEG‐4 v3, v2
`
`WMAudio v2
`
`Description
`
`MS MPEG‐4 video codec; up to 30 fps QCIF ﴾176x144﴿ ‐ CIF ﴾352x288﴿ resolution video at
`28.8 kbps – 300 kbps
`
`New Windows Media audio codec based on non‐uniform modulated lapped
`bioorthogonal transforms ﴾NMLBT﴿ in place of DCT for perceptual coding of both voice
`and high‐fidelity; 8 – 48 kHz stereo at 56 – 128 kbps; near‐FM quality at 28.8 kbps and
`near‐CD quality at 64 kbps
`
`ACELP.net
`
`Sipro ACELP voice codec; speech‐quality 8 – 16 kHZ mono at 5 – 16 kbps
`
`MPEG‐1 Layer 3
`
`Fraunhofer MP3 perceptual audio codec; near‐CD quality at 128 kbps
`
`https://msdn.microsoft.com/en­us/library/ms834433.aspx
`
`6/10
`
`Petitioner Alarm.com's Exhibit 1026
`1026.0006
`
`

`
`Multimedia Streaming on Microsoft Windows CE 3.0
`9/21/2016
`The componentization of the WMT for Windows CE allows you to build a fully customizable streaming media client that is
`tailored to your specific streaming environment. The WMT for CE has been fragmented such that you can decide which
`components to include in your application. Each of the following components can be selected as appropriate:
`
`MMS streaming
`HTTP streaming
`File streaming
`Broadcast and Multi Bit Rate Streaming
`Windows Media Station support
`ASX support
`Codecs
`DirectShow
`DirectShow provides the underlying services for playback of multimedia streams from either local files or over a network from a
`server. Specifically, DirectShow enables playback of video and audio content compressed in various file and streaming formats,
`including Windows Media, MPEG, Audio‐Video Interleaved ﴾AVI﴿, and WAV.
`
`Applications control filter graph activities by communicating with the filter graph manager. You can do this either indirectly by
`using the Microsoft Windows Media Player control, or directly by calling COM interface methods.
`
`At the heart of the DirectShow services are modular sets of pluggable components called filters that can be arranged depending
`upon media type into a connected configuration called a filter graph. Filters operate on data streams to read, parse, decode,
`format, or render them.
`
`Filters are arranged in a configuration called a filter graph, controlled by the Filter Graph Manager ﴾FGM﴿. A DirectShow filter
`graph ﴾see Figure 2﴿ consists of a directed sequence of filters from source to final renderers, all connected by input and output
`filter pins. Filter pins negotiate which media types they will support. The FGM controls the multimedia data flow between the
`graph filters. Because DirectShow has a flexible, re‐configurable filter graph architecture, DirectShow can support playback and
`streaming of many media types using the same software components. Developers can also extend DirectShow multimedia
`support by writing their own filters.
`
`Figure 2. DirectShow Filter Graph
`
`Filter Graph Manager
`An application uses the Filter Graph Manager ﴾FGM﴿ interfaces to create, connect, and control filter graphs. Filters use the FGM
`interfaces to post event notifications and to force reconnection of the filter pins as needed. In particular, the IGraphBuilder
`interface allows applications to call the filter graph manager to attempt to build a complete filter graph, or a partial filter graph if
`given only partial information such as the name of a file or the interfaces of two separate pins. The filter mapper looks up the
`available filters in the registry to configure the filter graph in a meaningful way. The IGraphBuilder interface creates a filter
`
`https://msdn.microsoft.com/en­us/library/ms834433.aspx
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`7/10
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`Petitioner Alarm.com's Exhibit 1026
`1026.0007
`
`

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`Multimedia Streaming on Microsoft Windows CE 3.0
`9/21/2016
`graph, adds filters to or removes filters from a filter graph, enumerates all the filters in a filter graph, and forces connections
`when adding a filter. To cause the appropriate filter graph to be constructed, an application just needs to create an instance of
`the IGraphBuilder interface and then call its RenderFile method.
`
`In addition, the FGM exposes media control and media positioning interfaces to the application. The media control interface,
`IMediaControl, allows the application to issue commands to run, pause, and stop the stream. Playback starts when the Run
`method is invoked. The positioning interface, IMediaSeeking, lets the application specify which section of the stream to play.
`
`Internally, the FGM will use the individual filter's well‐known BaseFilter interface to locate and enumerate a filter's input and
`output pins.
`
`Filters
`Filters are registered DirectShow classes and perform most media processing tasks. Filter tasks include:
`
`Source acquisition ﴾e.g., acquire a media stream﴿
`Parsing ﴾e.g., perform packet reading, splitting, and formatting on the stream﴿
`Transformation ﴾e.g., decode WMA and MPEG‐4 audio and video streams﴿
`Rendering ﴾e.g., generate audio PCM or video RGB/YUV output at the right time and pass data on to DirectSound and
`DirectDraw﴿
`
`Filters use several types of interfaces, such as pins, enumerators, transports, and clock interfaces to perform their tasks. Filters
`implement and expose numerous interfaces. The FGM uses these interfaces to create, connect, and control the graph. A filter will
`always implement the IBaseFilter interface that contains methods to:
`
`Run, stop, and pause filter state
`Retrieve filter and vendor information
`Get and set the reference clock
`Retrieve filter state information
`Enumerate filter pins
`Locate pins when rebuilding a filter graph
`
`Individual filters expose an IBaseFilter interface so that the Filter Graph Manager can issue the run, pause, and stop commands.
`The Filter Graph Manager is responsible for calling these methods in the correct order on all the filters in the filter graph. Your
`application should not do this directly.
`
`However, unlike the IBaseFilter interface, only the renderer filter exposes an IMediaSeeking interface. Therefore, the Filter
`Graph Manager calls only the renderer filter with positioning information. The renderer then passes this position control
`information upstream through IMediaSeeking interfaces exposed on the pins, which simply pass it on. The positioning of the
`media stream is actually handled by the output pin on the filter that is able to seek to a particular position, usually a parser filter
`such as the AVI splitter.
`
`Supported Filters
`Windows CE DXPAK 1.2 provides the following DX 6.1 DirectShow filters:
`
`Source Filters—File Source ﴾Asynchronous and URL﴿
`Parsers and splitters—MPEG‐1 Stream Splitter, AVI Splitter, QuickTime Parser, WAVE Parser, MIDI Parser, ASF Parser, ASX
`Parser, ASF Splitter
`Decoders—MSAudio Decoder, MPEG‐1 Audio Decoder, MPEG‐1 Video Decoder, MPEG‐4 Video Decoder, AVI
`Decompressor, ACM Audio Decompressor
`Renderers—Audio Renderer ﴾using WaveOut﴿, DirectSound Audio Renderer, MIDI Audio Renderer, Video Renderer ﴾using
`either DirectDraw or GDI﴿
`Miscellaneous filters—Overlay Mixer
`
`https://msdn.microsoft.com/en­us/library/ms834433.aspx
`
`8/10
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`Petitioner Alarm.com's Exhibit 1026
`1026.0008
`
`

`
`Multimedia Streaming on Microsoft Windows CE 3.0
`9/21/2016
`In order to support streaming of Windows Media Formats, special ASF/ASX streamer source and WMA codec transform filters
`are provided. In addition, the Fraunhofer MP3 audio and Sipro ACELP.net speech codecs use the Audio Compression Manager
`﴾ACM﴿ wrapper Audio Decompressor transform filter.
`
`DirectShow broadcast technology and DV filters are not included in DXPAK, but are available as part of the Windows CE WebTV
`Microsoft TV ﴾MSTV﴿ Kit.
`
`Example
`DirectShow makes it easy to play or stream multimedia files. Here is a sample code fragment showing how to write a trivial
`multimedia file player application ﴾note that we have, among other simplifications, suppressed checking the QueryInterface
`return status﴿.
`
`HRESULT PlayMovie(LPTSTR lpszMovie)
`{ 
`// we will use several DirectShow interfaces
`IMediaControl *pMC = NULL;
`IGraphBuilder *pGB = NULL;
`IMediaEventEx *pME = NULL;
`
`long evCode; // something to hold a returned event code
`
`// instantiate a filter graph as in‐proc server
`hr = CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC, 
`                        IID_IGraphBuilder, (void **) &pGB);
`
`// we’ll use this interface to build the graph
`hr = pGB‐>QueryInterface(IID_MediaControl, (void **) &pMC);
`
`// we’ll want to wait for completion of the rendering, so we need a media
`                     event interface
`hr = pMC‐>QueryInterface(IID_IMediaEventEx, (void **) &pME);
`
`// now we’re ready to build the filter graph based on the source file data
`                     types
`hr = pGB‐>RenderFile(lpszMovie, NULL);
`
`// play the source file
`hr = pMC‐>Run();
`
`// block application until video rendering operations finish
`hr = pME‐>WaitForCompletion(INFINITE, &evCode);
`
`// release interfaces
`}
`
`Several comments are in order. CoCreateInstance instantiates a filter graph object, but no filters, as it does not yet know what
`media types it needs for playback. It returns the IGraphBuilder interface needed to build the filter graph once the media type is
`known. A query interface is made to get IMediaControl for running, pausing, and stopping the streaming of media through its
`filters. Since Windows CE currently supports only in‐process COM servers, CLSCTX_INPROC_SERVER is the only valid server
`context for CoCreateInstance. Trying anything else will return E_NOTIMPL.
`
`IGraphBuilder is used to create a filter graph, add filters to or remove filters from a filter graph, enumerate all the filters in a
`filter graph, and force connections when adding a filter. We are using its RenderFile method to build the graph. The final graph
`construction depends upon the video and audio formats contained in source file. Finally, we can play back the file using
`https://msdn.microsoft.com/en­us/library/ms834433.aspx
`
`9/10
`
`Petitioner Alarm.com's Exhibit 1026
`1026.0009
`
`

`
`Multimedia Streaming on Microsoft Windows CE 3.0
`9/21/2016
`IMediaController::Run. Since we want the application to wait until the rendering is finished, we have added
`IMediaEvent::WaitforCompletion.
`
`For More Information
`You can find additional information about Windows CE DXPAK at
`http://www.microsoft.com/presspass/press/2000/Feb00/DxpackPR.asp.
`
`© 2016 Microsoft
`
`https://msdn.microsoft.com/en­us/library/ms834433.aspx
`
`10/10
`
`Petitioner Alarm.com's Exhibit 1026
`1026.0010