Has this ever happened to you: You get a new TV and after installing it and setting it up you sit down on the couch to watch some YouTube and you tap the Chromecast button and it just works. “Neat, I didn’t even have to do the Chromecast setup process”. But then at some point in the future you try and cast something like Twitch1 but casting to the TV isn’t an option?
You see, the Chromecast button you got when playing YouTube that first time was a lie. Your TV most likely was using the Discovery and Launch (DIAL) protocol, DIAL was used in the early days of Chromecast but no longer. Now, I’ll be honest, I haven’t dug into the two protocols and tried to learn the exact differences between them. My current understanding is this: DIAL will send out information telling a device what app to open and what additional parameters to pass to that app. For Chromecast, your phone sends a URL to a device that is a minimal web app that the device presents. (I believe DIAL doesn’t support things like device mirroring so probably no Chrome-tab mirroring) The biggest pain about DIAL is that so far it appears that a smart device with DIAL must have the corresponding app on both my phone and TV to work. I can’t just cast Pandora, or Twitch, or a Chrome tab to my TV.
The specific differences here aren’t what upsets me most though. What annoys me most is that for some reason, Google has decided that it will use the same icon to represent Chromecast and DIAL launching. There is no effort to make this distinction clear to consumers that their smart TVs may not actually be able to do what they want. Why didn’t Google protect its branding around Cast? It spent time and effort to develop its devices and protocol and now the same icon that used to mean one thing means nothing. Just put a little D or C in the Cast button depending on the protocol, at least that way there’s no surprises. It appears from Google’s Cast developer documentation that Google is possibly intentionally not differentiating between the two. There are no references to a specific protocol on their pages only that it allows casting to “Cast-enabled” devices.
TV and set top box manufacturer’s should be more up front about what their device truly supports. Hiding behind the Cast symbol is just frustrating for consumers. I hope in the future more TVs come with full Chromecast support built-in like I’m seeing from Sony. Someone has to be more forward about this because when discussing this with my friends in the tech world, barely any of them even knew that there were more protocols besides just “Cast” and AirPlay, which may have been Google’s goal…
1 At the time of writing the official Twitch app doesn’t support DIAL (or choosing video quality, grumble) on my TV.