Fun With Technology–Part VII

Important Update 27th October 2012: The bug described below has been fixed in the final release of Windows 8.

Hoorah!

Update 24 October 2013: With the release of Windows 8.1, I found another issue with “Play to”. I posted it in a Microsoft forum, and got some useful feedback from Microsoft’s Gabe Frost. The issue is not resolved, but at least we now know what’s going on. See https://gcoupe.wordpress.com/2013/10/23/play-to-and-windows-8-1/

Original Post

Here we go again – one step forwards, two steps back… Something that was working under Windows 7 has stopped working in the Windows 8 Consumer Preview, and that is the “Play to” feature of Windows Media Player.

Almost three years ago, I wrote a post (Fun With Technology – Part IV) describing my trials and tribulations with this feature of Windows Media Player in an early version of Windows 7. Sometimes it would seem to work, and sometimes it didn’t. I eventually found out, and described in that post, what was going on. I also identified how to get “Play to” working very satisfactorily for the devices on my home network. And there matters have rested until now, when I’ve found that Windows 8 Consumer Preview has broken things again.

First, let me recapitulate some of the background terms and technology specification used by Microsoft in its implementation of “Play to” and how I’m using it at home. These come from the Digital Living Networking Alliance, or DLNA for short. Their specification defines how a variety of different types of digital devices can connect and share information. This I’ve summarised in the following table:

Device Class What it does Examples
Digital Media Server (DMS) Stores content and makes it available to networked digital media players (DMP) and digital media renderers (DMR). Some digital media servers can also help protect your content once stored. PCs and network attached storage (NAS) devices
Digital Media Player (DMP)
Finds content on digital media servers (DMS) and provides playback and rendering capabilities. TVs, stereos and home theaters, wireless monitors and game consoles
Digital Media Renderer (DMR)
These devices play content received from a digital media controller (DMC), which will find content from a digital media server (DMS). TVs, audio/video receivers, video displays and remote speakers for music.
Digital Media Controller (DMC) These devices find content on digital media servers (DMS) and play it on digital media renderers (DMR). Internet tablets, Wi-Fi® enabled digital cameras and personal digital assistants (PDA).
Digital Media Printer (DMPr) These devices provide printing services to the DLNA home network. Generally, digital media players (DMP) and digital media controllers (DMC) with print capability can print to DMPr. Networked photo printers and networked all-in-one printers.

Table 1: Information drawn from the DLNA web site.

Windows 7 implements a number of these classes as shown here:

Device Class Windows Implementations
Digital Media Server (DMS) When media streaming is enabled, Windows acts as a DMS.
Digital Media Player (DMP)
Windows Media Player and Windows Media Center act as a DMP when browsing shared media libraries
Digital Media Renderer (DMR)
Windows Media Player acts as a DMR when configured to allow remote control of the Player.
Digital Media Controller (DMC) The “Play To” feature from Windows Media Player launches a DMC to control the media playback experience

Table 2: Information drawn from the Engineering Windows 7 Blog.

At its simplest, just two devices can be involved: a Server and a Player. These can even be running on the same physical device, as in the case where your Windows Media Player on your Desktop PC is streaming music or video stored on the PC itself. The next step up is where the server and player are on separate physical devices. Two typical scenarios are shown in figure 1:

WMP Scenarios
Figure 1: Typical scenarios of simple case of DMP devices accessing DMS devices.

I’ve used the Denon AVR3808 as an example, since this is what I have in my home network. My DMS is a headless (no monitor, keyboard or mouse) home-built PC running the Windows Home Server 2011 operating system.

In my particular case, both the two scenarios shown above will work, that is, the DMS that is part of WHS 2011 will stream audio to other PCs in the home network, and to the Denon AVR3808. Under the covers, there’s actually some negotiation of streaming formats going on. This is because I have stored all my music files on the WHS 2011 in Windows Media Audio Lossless (WMAL) format. This presents no problems for the PCs, since the Windows Media Players installed on them can handle WMAL. But while the Denon can handle standard Windows Media Audio, it can’t handle the Lossless variant. So when I use the Denon to browse my music library on the server and select a track to play, the DMS in WHS 2011 sees that the Denon can’t handle WMAL and transcodes the stream into a format that the Denon can handle on the fly.

The interesting scenarios are where there are three devices linked together: a Digital Media Server, a Digital Media Controller, and a Digital Media Renderer.

WMP Scenarios 2
Figure 2: Typical scenarios of a three device link (DMS-DMC-DMR).

In my case, all flavours of scenario 3 will work. That is, I can stream from my Windows Home Server using the “Play To” feature of Windows Media Player running in either Windows 7 or Windows 8 Consumer Preview, and push the stream to PCs that are running Windows 7 or the Windows 8 Consumer Preview.

But while scenario 4 works if “Play to” is running in Windows 7, it does not work if “Play to” is running in Windows 8 Consumer Preview.

Here’s a screenshot of the “Play to” of Windows Media Player running in Windows 7, and streaming a WMA Lossless file to my Denon:

WMP 12 12

The WMA Lossless file is held on the WHS 2011 system, and is being transcoded into a different format on the fly so that the Denon can play it. I’m not sure whether the transcoding is being done on the Windows 7 PC (where the Windows Media Player is running), or whether it is being done at source on the WHS 2011 system. Either way, the Denon is being fed with a stream in a format that it understands, so it plays it without problem.

Now look at the following screenshot. It’s the very same music file that has been chosen from the Music Library held on the WHS 2011 system, but this time the “Play to” and the Windows Media Player are running on Windows 8 Consumer Preview:

WMP 12 11

As you can see, the Denon is reporting an error – it can’t play the file. I’m pretty sure that this is because no transcoding is being done – the WMA Lossless file is being sent straight to the Denon.

In Windows 8, the Windows Explorer also has the “Play to” feature, and the same error occurs:

WMP 12 13

So, to sum up; something has been broken in the “Play to” feature in Windows 8 Consumer Preview. Hopefully it will get fixed before Windows 8 is released

About Geoff Coupe

I'm a British citizen, although I have lived and worked in the Netherlands since 1983. I came here on a three year assignment, but fell in love with the country, and one Dutchman in particular, and so have stayed here ever since. On the 13th December 2006 I also became a Dutch citizen.
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One Response to Fun With Technology–Part VII

  1. Pingback: Fun With Technology – Part VIII | Geoff Coupe's Blog

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