Network Playback, Buffers, Continuous Stream, etc...

[The Computer Audiophile]

Hi Guys, I've been thinking about the conversations about network buffers and some peoples' experiences and beliefs with respect to how network playback works. There's not a single "this is how it works" statement to be made, but I think a good discussion could pull out some details that may educate people. 

 

Let's start by looking at this screenshot below. I'm playing a 24/192 album from my CAPS Twenty Windows 10 PC, with a 10 Gbps network card, acting as the Roon core, connected to a 10 Gbps switch, connected to a Sonore opticalRendu as the Roon endpoint (connected to the same switch). You can see Roon at the bottom of the screen and the network stats at the top. I've marked the areas on the graph where there's transition from one track to another. 

 

Many people assume that tracks are sent to the audio endpoint at full speed, then network activity stops until the next track needs to be played. Based on this screenshot, it appears that audio is sent continuously to the endpoint and only stops when transitioning from one track to the next. 

 

I will do the same thing for DLNA and use the exact same hardware.

 

 

 

 

[The Computer Audiophile]

Here is the exact same graph streaming from JRiver Media Center via DLNA to the opticalRendu. Same thing. Continuous streaming. 

 

Please note the scale is different because that's just what Windows does. I noted the speed in bold letters on the left. 

 

I do have flow control enabled on my switches but I'm not sure if this would be solely responsible for not sending the entire track in one shot. 

 

 

[The Computer Audiophile]

Here's the same hardware, but the opticalRendu is configured as an HQPlayer NAA. Roon is running on CAPS Twenty and HQPlayer is running on CAPS Twenty. HQP is sending the audio to the oR. You can see it streams continuously and, by design, doesn't even breakup the tracks. 

 

[The Computer Audiophile]

Here's the same thing using HQP / NAA without Roon.

 

[The Computer Audiophile]

Here's what's on the switch and which ports the audio devices are on. 

 

[The Computer Audiophile]

11 minutes ago, plissken said:

the endpoints determine the buffering

 

 

7 minutes ago, jabbr said:

This is my experience using my NAA devices whether they are the Clearfog (1Gbe) or "PC" (10Gbe)

 

These two statements are incongruous. 
 

Im not out to prove anything but I’d like to figure out more how and why stuff. 

[The Computer Audiophile]

3 minutes ago, plissken said:

 

No it's not incongruous. Endpoint equals hardware + software.

Can you be more specific than, “I always use a PC?” If endpoint is hardware, software, firmware, etc... what do you always use?

 

I don’t believe the endpoint determines much. If I disable flow control I can overwhelm many endpoints. Roon Server determines its flow, not the endpoint. 

[The Computer Audiophile]

1 hour ago, One and a half said:

why is 10GBe used?

Because the motherboard in the CAPS server came with a 10 Gbps card. 

[The Computer Audiophile]

I think the more we look at this the clearer it is that there’s no standard or reference design for how any of this works with respect to audio endpoints. There are countless ways to get audio and/or data from disk to the DAC. 

[The Computer Audiophile]

For those with spikes during playback, does the entire track get sent, thus enabling the cable to be pulled (if you actually wanted)?

[The Computer Audiophile]

8 minutes ago, plissken said:

 

I just want to add some color, from my posting history, about this statement. I've always spoken about what I consider the best approach for me and under what circumstances. I've never made any statements about any scenarios, software+endpoint hardware that I haven't thrown under the microscope. I know how to pick the hills I'm willing to die on ;-)

 

That is JRiver and Tidal will buffer up entire tracks as quick as wire speed allows. I've even made the point that using Roon as a front end for Tidal breaks this buffering model.

I totally hear you on this. I think the topic is really interesting because many people think they know how this works, but they've only read post on forums, that suggest one way or another. I'm not pointing any fingers at you. In fact, i'd love your continued help and input. The fact that you have a method that works in the opposite way as what I've tested is great. I'm going to run tests on my similar setup this afternoon and post the results. 

 

My goal is to get more information in peoples' hands. I think this thread so far has started on the right path to do this. 

[The Computer Audiophile]

Here is my test with JRiver running on CAPS Twenty, sending to JRiver running on CAPS Twenty.One. The behavior, without changing any "major" settings, is to send the whole audio file to the endpoint at the start of the track and then rest. I can't see the sending rate because Windows sets the scale automatically too low. 

 

@plissken Do you know how to manually change the Windows network activity monitor scale? When using JRiver it is way to small, with the maximum being either 1 Mbps or 11 Mbps.

 

 

[The Computer Audiophile]

Here's Roon on CAPS Twenty sending to Roon Bridge on CAPS Twenty.One. Very different from JRiver to JRiver. 

 

[The Computer Audiophile]

11 minutes ago, Miska said:

 

They probably made some contract about use of the tech before Google shot down it's Chromecast Audio.

 

Let's see if it is still around after 5 - 10 years.

 

Google owns a 41% stake in StreamUnlimited, the company supplying the cards used by the companies offering Google Cast support. 

[The Computer Audiophile]

35 minutes ago, Miska said:

 

If they are so interested on this stuff, they could as well fix the protocol for gapless playback then? They could probably do it without too much trouble?

 

Or maybe it is very little of interest for them, with main interest being in video playback? And game streaming from the cloud, for which they are selling package of game controller and Chromecast Ultra.

 

I don’t think there is any interest in gapless from Google, or HiFi for that matter. StreamUnlimited has IP that’s cheaper and quicker to purchase than create itself, so Google just wrote a check. 

[The Computer Audiophile]

Here's a good screen recording of Roon pulling a 24/96 track from Qobuz, then streaming it to an opticalRendu. You can see the receiving Ethernet speed hit 818 Mbps and the sending Ethernet is a steady continuous stream to the endpoint. 

 

 

[The Computer Audiophile]

26 minutes ago, plissken said:

You aren't playing directly off the wire, your are indeed playing out of buffer

It's impossible to do anything off the wire. Computers just don't work that way.