[Galaxy Note 10.1 (2014 Edition) General] BarryH_GEG:
It's a bunch of folks trying to figure out how to apply different functions from the SDK/APIs. To me, it shows there are a ton of varibles and options available to developers and probably more than one way to do the same thing.

I thought this was interesting...

Hi, I'm able to see the volume level on Chromecast when I call setVolume on the sender side during the Preview SDK days. But this is no longer available in the Public SDK, setVolume don't trigger any UI on the receiver side although the audio level do change (I'm using the default media receiver). I felt that the visual feedback on volume level change should be shown by default as this is the standard expectation on TV. or have I missed out anything? is there an extra steps to trigger the UI on the receiver?﻿

Yup I'm using the wrong api, I should be using the Cast.CastApi.setVolume(). After changing to that api, the volume UI appears now. Thanks.

I was mislead by the Preview SDK, where I used to call MediaProtocolMessageStream.setVolume() to change volume.​

Volume either as a control or indicator can be integrated in to Chromecast apps on both the client and receiver side. Maybe some devs are misusing an API related to volume that conflicts with some of Samsung or Android's code on the device? Someone's coloring outside the lines and creating conflicts with other apps or an API itself isn't performing as published. Since some apps work and others don't here's some things to consider:

Apps that work don't use the volume control API or are applying it differently than apps that don't work.

Apps that work have their own receiver s/w (vs. using the standard HTML5 imbedded player) and the custom s/w written for them don't use the volume control API or replace it with something proprietary.

Apps that don't work have their own receiver s/w and the custom s/w written for them is written incorrectly as it applies to the volume controls.

Developers of broken apps didn't apply the volume API correctly.

Samsung's moving the volume control to the notification panel is new. The API calls and integration they are using may be perfectly valid but may have never been used before. App devs may have taken shortcuts before with no affect that are now visible because of the new valid (but previously unused) code/APIs Samsung's introduced is breaking them.

Samsung is using non-standard code/calls to get the volume control in the task bar and in doing so created the potential for conflict with other apps that are also trying to control volume in non-standard ways. Samsung does lots of user acceptance testing so if whatever they've done broke a lot of things it would most likely have been caught. This actually started in January with the launch of the Pro's. N10.1-14 owners are just feeling the delayed impact because our 4.4 code is based off the Pro's.

Google's doing something non-published in their client apps that cast to Chromecast that's causing a problem. Since they own Android they can pretty much do whatever they want.

The OS controls volume. Individual apps just send it instructions via an API/code. As long as everyone colors between the lines it shouldn't matter when, where, or what the volume controls look like or when they appear. If you touch the right sight of the display when Samsung's stock video player is running you'll see a vertical volume control appear. Touch the left side and the same thing happens for brightness. In and of itself apps independently manipulating OS controls like volume and brightness isn't a problem.