+- MinimServer Forum (https://forum.minimserver.com)
+-- Forum: MinimServer (/forumdisplay.php?fid=1)
+--- Forum: General (/forumdisplay.php?fid=2)
+--- Thread: Dumb question re how minimserver works (/showthread.php?tid=3620)
Pages: 1 2
Dumb question re how minimserver works - Martin H - 05-10-2016 17:40
Simon,
I was just wondering how minimserver works exactly in a Linn DS setup. For instance to play an album does the control point ask minimserver for the list/location for that album and then the control point sends it to the DS. Then holding that info in its current playlist, the DS requests the stream of each track from the Server?
Or can the server push a track list directly to the DS, or maybe even just start streaming to it? I am guessing the first para is right and this last one is wrong?
RE: Dumb question re how minimserver works - Peter@57m - 05-10-2016 21:02
Martin,
The former - see this explanation on Linn Docs
http://docs.linn.co.uk/wiki/index.php/Introduction_To_DS_Concepts
RE: Dumb question re how minimserver works - Martin H - 06-10-2016 00:12
(05-10-2016 21:02)Peter@57m Wrote: Martin,
The former - see this explanation on Linn Docs
http://docs.linn.co.uk/wiki/index.php/Introduction_To_DS_Concepts
Thanks - I thought so. I get the impression that DLNA devices might be the other way around i.e. the control point tells the server to send content to the device which it then processes. Or at least I think that's correct. It was the Linn situation I was enquiring about - thanks.
RE: Dumb question re how minimserver works - Peter@57m - 06-10-2016 08:19
Found this on Wikipedia. So I believe it's the same as native Linn it's just that when the components communicate with each other, they talk a different language when using DLNA than Linn Openhome.
Home Network Devices
Digital Media Server (DMS): store content and make it available to networked digital media players (DMP) and digital media renderers (DMR). Examples include PCs and network-attached storage (NAS) devices.
Digital Media Player (DMP): find content on digital media servers (DMS) and provide playback and rendering capabilities. Examples include TVs, stereos and home theaters, wireless monitors and game consoles.
Digital Media Renderer (DMR): play content as instructed by a digital media controller (DMC), which will find content from a digital media server (DMS). Examples include TVs, audio/video receivers, video displays and remote speakers for music. It is possible for a single device (e.g. TV, A/V receiver, etc.) to function both as a DMR (receives "pushed" content from DMS) and DMP ("pulls" content from DMS)
Digital Media Controller (DMC): find content on digital media servers (DMS) and instruct digital media renderers (DMR) to play the content. Content doesn't stream from or through the DMC. Examples include tablet computers, Wi-Fi enabled digital cameras and smartphones.
Generally, digital media players (DMP) and digital media controllers (DMC) with print capability can print to DMPr. Examples include networked photo printers and networked all-in-one printers
RE: Dumb question re how minimserver works - Martin H - 06-10-2016 11:02
Thanks Peter. I have half a memory that there are different ways to do this. At a low level -
- One is where the renderer in effect is told what to ask for from the server, by the control point, and the renderer then initiates and processes the stream. (As Linn does). The other solution is that the server is told what to send, and where to send it, by the control point. The render simply processing what it receives. The former is the Upnp model as I understand it but I can't remember what the other one called.
TBH it may be that my memory is faulty, that the explanation of this difference that I had read was flawed or based on a misunderstanding by the author of how it works 'underneath'. It's not critical, just annoying. I appreciate your help. I have checked a few sites and pretty sure that you are right re DLNA and UPNP which are described as cousins. Thx againk
RE: Dumb question re how minimserver works - DavidHB - 06-10-2016 11:21
Peter's definitions relate to DLNA. The device definitions for UPnP AV are slightly different, but, because DLNA uses the UPnP messaging protocol, the two standards are essentially inter-operable. However, UPnP does not seem to include a device definition like the Digital Media Player, i.e. one that autonomously pulls content from the server; it only has the Control Point which issues instructions for the server to provide content to the renderer using the playlist, which is only active within the control point software.
The issue with UPnP AV is that, for the renderer to continue to function, the control point has to remain active, while devices such as phones and tablets that are the typical hosts for control point software readily go into standby to save power. OpenHome (originally developed as an extension to UPnP AV under the sponsorship of Linn, but fully open and now used by some other manufacturers as well) actually has a 'halfway house' pull feature. The control point is still used to build the playlist but, when it is created or amended, it is saved in the renderer, which then uses the playlist to pull the content from the server. If you put your DS in standby when it has a playlist loaded, the playlist will still be there when the player is active again.
This approach has two advantages. Firstly, the renderer can continue playing even when the control point shuts down, and the user can switch seamlessly between control points while the renderer is still playing. Also, from the user perceptive, the renderer works almost like a CD player with a disc loaded; the user can use the remote control or the front panel to work the 'transport' functions of the renderer (play, pause, track change etc) directly, that is without using or needing a control point.
Apart from this difference, OpenHome also provides other features, in particular it implements gapless playback. This, I believe, is also a feature in UPnP AV, but it is by no means always implemented.
Interestingly, the Linn document to which Peter linked does not mention the difference between UPnP AV and OpenHome. Linn DS and DSM devices offer a UpnP AV compatibility mode (without gapless playback), but there is no reason to use it with MinimServer or control points such as BubbleDS and Kazoo, all of which are fully OpenHome compliant.
David
RE: Dumb question re how minimserver works - Cebolla - 06-10-2016 16:51
(06-10-2016 11:21)DavidHB Wrote: Peter's definitions relate to DLNA. The device definitions for UPnP AV are slightly different, but, because DLNA uses the UPnP messaging protocol, the two standards are essentially inter-operable. However, UPnP does not seem to include a device definition like the Digital Media Player, i.e. one that autonomously pulls content from the server; it only has the Control Point which issues instructions for the server to provide content to the renderer using the playlist, which is only active within the control point software.Strictly speaking, the UPnP AV Architecture document does actually define a couple of 2-Box models, in addition to the general device architecture aka 3-Box model (consisting of control point, MediaServer & MediaRenderer components). One of those 2-box models describes the interaction between a combined control point with Decoder component and the (standard) MediaServer component; so the control point with Decoder (combined) UPnP component or 'box' does seem to fit into the DLNA definition of a DMP.
RE: Dumb question re how minimserver works - bubbleguuum - 06-10-2016 21:10
(06-10-2016 11:21)DavidHB Wrote: Apart from this difference, OpenHome also provides other features, in particular it implements gapless playback. This, I believe, is also a feature in UPnP AV, but it is by no means always implemented.
OH does not make gapless a requirement. An OH renderer can very well not be gapless. OH makes it slightly easier though as an OH renderer always knows the next track, without needing special support from the Control Point (which in the UPnP AV case, must explicitly inform the renderer what the track after the playing track is, for gapless).
RE: Dumb question re how minimserver works - DavidHB - 06-10-2016 22:17
(06-10-2016 21:10)bubbleguuum Wrote:(06-10-2016 11:21)DavidHB Wrote: Apart from this difference, OpenHome also provides other features, in particular it implements gapless playback. This, I believe, is also a feature in UPnP AV, but it is by no means always implemented.OH does not make gapless a requirement. An OH renderer can very well not be gapless. OH makes it slightly easier though as an OH renderer always knows the next track, without needing special support from the Control Point (which in the UPnP AV case, must explicitly inform the renderer what the track after the playing track is, for gapless).
This is understood; in fact, I said that OpenHome implements gapless playback, not that it mandates it. That said, are you aware of any native OpenHome devices (i.e those that have OpenHome built in, rather than those created by BubbleUPnP Server) that do not provide gapless playback?
I am also grateful for the explanation of the difference between OH and UPnP AV in the implementation of gapless playback, which makes obvious sense, given the differences between the two protocols.
David
RE: Dumb question re how minimserver works - DavidHB - 06-10-2016 22:36
(06-10-2016 16:51)Cebolla Wrote: Strictly speaking, the UPnP AV Architecture document does actually define a couple of 2-Box models, in addition to the general device architecture aka 3-Box model (consisting of control point, MediaServer & MediaRenderer components). One of those 2-box models describes the interaction between a combined control point with Decoder component and the (standard) MediaServer component; so the control point with Decoder (combined) UPnP component or 'box' does seem to fit into the DLNA definition of a DMP.
This is interesting. I was only previously aware of the 3 box model. To refresh my memory, I looked up this Wikipedia article, which provides a list of UPnP components. None of the components listed there seems to fit the DMP concept; do you have a reference to the definition of the 'combined' component?
Of course, in reality a single hardware device can host the whole of a UPnP AV or OpenHome system. My own desktop computer has instances of MinimServer, control points (Kazoo and Kinsky) and renderers (the OpenHome renderer and foobar2000). But the OP's question related to the mode of operation ('pull' or 'push') of a Linn DS, rather than the number of boxes in the system.
David