Users who have a DMP device can browse and request content from a Windows PC that is acting as a DMS for playback in the DMP. The functionality in Windows Vista was expanded by adding support for new formats and by including support for transcoding operations.
Windows 7 also performs the DMP role. Figures 15 and 16 show Windows Media Player and Windows Media Center acting as a media player. Whenever a media item is selected from the shared library of a media server and played, Windows Media Player and Windows Media Center are acting as a DMP.
Figure 15: Browsing Erica’s shared music library for playback in Windows Media Player
Figure 16: Browsing Erica’s shared music library for playback in Windows Media Center from the shared library pivot
DMP devices are fundamental for advancing the ecosystem of networked devices in the home. However, the new Windows Logo Program (WLP) will not certify devices that implement only the DMP role. We encourage companies to continue building devices with DMP functionality. In addition, we require the inclusion of the DMR role to interoperate with the Windows 7 Play To feature, as described in the precedingscenarios.
The rationale for this decision is simple. Families are storing several thousand pictures, audio files, and video files on PCs and other storage devices on their home networks. Managing this media content for one or more media libraries is an activity that is suited to the information management functions of a computer. Large media databases make it challenging to find items. Windows 7 addresses this problem through integrated search, tagging, and unified metadata across media applications and Windows Explorer. Searching for a song from a particular artist or searching for a family vacation photo is fast compared to browsing a file structure.
Artist (frans. artiste - bilimdon; lot. ars, artis - kasb, hunar, sanʼat) - dramatik spektakl, kinoda rollar, ope-ra va balet partiyalari, estrada konserti va sirk nomerlari ijrochisi. Teatr va kinoda aktyor, aktrisa deb ham yuriti-ladi.
By including the DMR role in devices, users can take full advantage of Windows capabilities for interacting with and searching media, while playing the content to the selected network media device by using the Windows 7 Play Tofeature.
Figure 17 shows the protocol layers in a digital media player. DMP devices support Wi-Fi or Ethernet for connectivity. DMP devices implement TCP/IP, UDP/IP, and HTTP. They implement the UPnP Media Server Control Point functionality to browse the media library in any networked DMS. DMR devices implement HTTP and extensions to receive content from a DMS. Some use RTP for transfer.
Figure 17. Protocol stack for a digital media player
Digital Media Controllers
Users who have DMC devices can browse content from any Windows PC and play that content in any other Windows PC or device that is connected to the home network and that implements the DMR role. Windows 7 implements a DMC, which is necessary to the Play Tofeature that was described earlier. After a DMR is selected for playback, the media controller is started to remotely control the playback experience. A user can have multiple media controllers open at any time and controlling playback to an equal number of DMRs in the network. Figure 18 shows this media controller, from which the following playback controls are available: Play, Pause, Stop, Mute, Volume, Next Item, Previous Item, Seek Forward, and Seek Backward.
Figure 18. Windows 7 DMC controlling playback when the Play To feature is used in Windows Media Player and Windows Explorer
For example, a user can have network media devices that implement the DMR role in every room of the home. The family room DMR is an HDTV that supports playback of video, music, and pictures, and the bedroom DMR is a digital picture frame. The DMR for the kitchen and den is a network radio that supports only audio. From a Windows 7 PC, a user can concurrently send pictures to the bedroom digital picture frame, video to the family room HDTV, jazz music to the kitchen, and rock music to the den.
Figure 19 shows the protocol layers in a digital media controller. DMC devices support Wi-Fi or Ethernet for connectivity. DMC devices implement TCP/IP, UDP/IP, and HTTP. They implement the UPnP control point functionality that includes a media server control point and a media renderer control point.
Figure 19. Protocol stack for a DMC
Building a Great Network Media Device
A great network media device must meet the expectations of today’s users: discoverability, ease of installation and configuration, quick startup, and outstanding rendering that is free from delays.
Initial Network Media Device Discovery and Installation
Before the user can configure a media device, Windows 7 must discover the device and give the user a configuration interface. This initial device discovery and the subsequent configuration must continue smoothly and easily so that the user does not become frustrated, or worse, return the device. Network media devices must provide a great out-of-box experience for consumers.
In the past, it was fairly easy to set up a wired device, but rather challenging to set up a wireless device. The wireless technology got in the way of a great user experience. In Windows 7, the experience of setting up network devices is greatly improved because of new mechanisms for uniformly discovering and installing both wired and wireless devices.
To take advantage of the new discovery and installation features in Windows 7, device manufacturers must include device description document metadata for Plug and Play Extensions (PnP-X). This metadata is required by the NETMEDIA-0008, 0009, and 0010 network media device requirements. If a wireless interface is present, implement Wi-Fi Protected Setup (WPS) as required by the Connect-0099 Rally program requirements to receive a Windows logo. These capabilities enable Windows 7 to discover a device even if it has not associated with the wireless network (meaning that it does not yet have an IP address) and provide a simplified experience of configuration and installation directly from the Windows PC. The user out-of-box experience for a new network media device is as follows:
1. Remove the device from its package and plug it into a power outlet.
2. Connect audio and video cables if available.
3. From the Windows 7 PC Control Panel, under Hardware and Sound, choose Add a device.
4. Select the newly discovered network media device from a list of new devices and follow the wizard to install and configure the device.
Figure 20 shows the Windows 7 experience for adding and configuring a device.
Figure 20. Adding a new network media device in Windows 7
This single process:
Associates the wireless media device with the network by letting the user create a wireless profile or to specify an existing profile.
Retrieves available drivers from Windows Update, based on the identifying information that is specified in the device description document PnP-X metadata. It also retrieves a metadata package that provides a photorealistic icon and other manufacturer-specific details for display in Windows.
Installs the device and starts any associated software installations that are specified in the retrieved driver package.
Windows 7 provides a baseline installation experience that uses a simple driver package and default icons for each network media device class. However, manufacturers have lots of flexibility to brand their devices in Windows by submitting driver and metadata packages for their devices.
Internet Protocol Addressing
Network media devices must provide support for obtaining IP addresses without requiring user intervention. According to guidelines provided by DLNA, network media devices should be able to obtain an IP address by using either Dynamic Host Configuration Protocol (DHCP) or Automatic Internet Protocol (AutoIP) addressing. The expectation is that a home network has a router that acts as a DHCP server, but devices can use AutoIP to remain connected if the DHCP server fails.
Staying Connected and Troubleshooting
Network media devices must implement Link Layer Topology Discovery (LLTD) as specified in the Connect-0098 Rally program requirement. Any device that implements LLTD appears on the Windows Network Map as an icon that represents the device. This enables one-click access to the device's Web UI for troubleshooting and changing the device friendly name as required by NETMEDIA-0017 and 0018.
Support for LLTD is required for non-mobile DMRs and DMS. For more details, see the LLTD specification at “LLTD and QoS for Media Experiences” on the WHDC Web site.
To achieve the device discovery and installation experience, the manufacturer of a network media device must provide a UPnP device description document that contains at least the pnpx:X_deviceCategory and pnpx:X_compatibleId metadata elements. Windows 7 uses these metadata elements to discover DMR devices and DMS devices that are available for installation and to display appropriate icons and manufacturer-specific metadata for the device.
Digital Media Renderer Requirement NETMEDIA-0009
A DMR device must provide the following information in the device description document, unless the device specifies its own unique pnpx:X_compatibleId and associated pnpx:X_hardwareId for associating a custom driver and metadata package:
The DMR role is typically one of many that a network media device implements, so we encourage device manufacturers to specify more than one pnpx:X_deviceCategory, where the first category that is specified represents the actual product form-factor of the device instead of the logical DMR role.
For example, a digital picture frame that implements the DMR role could specify the following device categories:
A DMS device must provide the following information in the device description document, unless the device specifies its own unique pnpx:X_compatibleId and associated pnpx:X_hardwareId for associating a custom driver and metadata package:
The DMS role is typically one of many that a network media device implements, so we encourage device manufacturers to specify more than one pnpx:X_deviceCategory, where the first category that is specified represents the actual product form-factor of the device instead of the logical DMR role. For example, a network-attached storage that implements the DMR role might specify the following device categories:
A device manufacturer can customize the user experience by specifying its own unique pnpx:X_compatibleId instead of the default MS_DigitalMediaDeviceClass_V001. If the manufacture chooses to specify its own compatible ID, it must also include a globally unique identifier (GUID) pnpx:X_hardwareId element in the device description document. The manufacturer must submit to Microsoft any metadata or driver packages that are associated with customizing the user experience. For details on how to create a customized experience, see ”Creating and submitting a device driver package” and “Creating and submitting a device metadata package” in “Resources” at the end of this document.