p*******m
发帖数: 20761 | 1 Miracast, Google Cast, Chromecast, AirPlay, Amazon Fling, and DIAL are all
different protocols that allow you to wirelessly send video from one device
to another. Some are open standards, while others are proprietary protocols.
Some work with the Fire TV out of the box, others can be made to work
through third-party apps, and others are incompatible with Fire TV devices.
This article will help you understand the differences between the protocols
and how they relate to the Amazon Fire TV and Fire TV Stick.
Discovery And Launch (DIAL)
Discovery And Launch, more commonly known by the acronym DIAL, is one of the
older protocols. It is a good place to start because it is probably the
least known protocol and is often confused for Miracast and Google Cast/
Chromecast. This open protocol was co-developed by Google and Netflix, and
is available for any developer to use in their apps. DIAL allows an app on
one device to detect the presence of an app on a second device, as long as
both devices are on the same network. Once a DIAL-enabled app (typically on
a smartphone) detects its sister app (typically on a TV-connected device),
it can send simple commands to the sister app. These commands including
launching the sister app, telling it to start playing a stream, and
controlling that playback. The video being played is not sent from one
device to the other. Only information about where to find a video is sent,
which is why the controlling/sending app can be exited and the playing/
receiving app will continue to play the video. DIAL is not a mirroring
protocol, so it cannot be used to display the entire screen of one device on
a different device.
Fire TV devices support DIAL out of the box, in the sense that third-party
apps on Fire TV devices can use the DIAL protocal. Without a DIAL compatible
app installed on the Fire TV, the Fire TV will not appear as a destination
for remote video playback within apps using DIAL. The YouTube app on Android
, iOS, and Fire TV devices use DIAL to communicate. Many people mistakenly
think they are using Miracast or Google Cast/Chromecast when they send video
from the YouTube app on an Android or iOS device to a Fire TV device. They
are actually using DIAL and the YouTube app must be installed on the Fire TV
for the Android or iOS device to see the Fire TV device as a receiver.
YouTube in particular causes a lot of confusion with Fire TV device owners
because the YouTube app appears to treat the Fire TV the same way it treats
a Chromecast device. This leads many people to think the Fire TV can receive
video from all Google Cast/Chromecast compatible apps. This is not the case
. The Fire TV is not a Google Cast/Chromecast receiver and does not work
with the vast majority of Google Cast/Chromecast compatible apps because the
vast majority do not use DIAL.
Google Cast/Chromecast
Google Cast, sometimes incorrectly referred to as Chromecast, is a
proprietary protocal used exclusively with Google’s Chromecast device. Any
app developer can implement Google Cast into their app as a sender, but only
Google’s Chromecast device can receive the video stream information. You
can think of Google Cast as the closed version of the open DIAL protocol.
The two share several characteristics, but Google Cast is much more popular
among app developers, which is why when an app uses DIAL, it is often
mistaken for Google Cast, leading to confusion with consumers.
Google Cast is capable of sending video stream information to a Chromecast
device. The Chromecast can then play the video stream independent of the
device communicating with it through Google Cast. Additionally, Google Cast
can be used to directly send a video stream from a device to a Chromecast
device. This is what is used to mirror a portion of a device’s screen onto
a Chromecast device. In either use case, both the sending device and the
Chromecast must be on the same network.
Some intrepid developers have tried to reverse engineer the closed Google
Cast protocol so that devices other than the Chromecast can be used as a
Google Cast receiver. This is most commonly seen as Android apps that claim
to “turn any Android device into a Chromecast.” The problem is that Google
is very protective of their closed protocol and actively take down these
apps or change their protocol to make these apps incompatible. The Fire TV
received such an app in the past, but Google quickly had it pulled from the
Amazon appstore. The takeaway is that Google Cast is closed and proprietary,
which is why it is not compatible with Fire TV devices.
Apple AirPlay
AirPlay is Apple’s proprietary protocal that Apple devices use to send
audio and video from one device to another. It is similar to Google Cast in
that the devices must be on the same network. It can be used to send video
streams or to mirror one device’s screen onto another device. Apple does
license AirPlay to manufacturers of audio devices, so there are numerous
speakers that can officially receive an AirPlay audio stream. However, Apple
does not license the video aspect of AirPlay, so the only device that can
officially receive AirPlay video is the Apple TV.
You may have noticed that I used the word “officially” several times. That
is because, unlike Google, Apple does not actively take down apps which
unofficially add AirPlay capabilities to non-Apple devices. This is why you
can regularly find Android apps that claim to turn a device into an AirPlay
video receiver, but you cannot regularly find Android apps that receive
Google Cast video.
The Fire TV does not support AirPlay out of the box, but there are several
Fire TV apps that can add AirPlay capabilities. The important thing to know
is that AirPlay is a closed protocol, so every single AirPlay app is
unofficial and has reverse engineered the protocol. This means that changes
to the AirPlay protocol made by Apple will break these apps until their
developers can reverse engineer the changes and implement them into their
apps. This is why most, if not all AirPlay apps for the Fire TV have poor
ratings. It’s very common for these AirPlay apps to stop working when a new
version of iOS is released by Apple. While I have not tried every AirPlay
app, I personally use AirReceiver as my AirPlay app of choice, but before
buying it, understand that it is common for it to not work, just like every
other AirPlay app in the Fire TV appstore.
Amazon Fling
Amazon Fling is a proprietary protocal developed by Amazon specifically for
the Fire TV. Since open standards, like DIAL and Miracast, were being
abandoned by developers and manufacturers in favor of Google Cast and Apple
AirPlay, Amazon had to release their own protocol or be left behind. As you
’d expect, Amazon Fling is supported on the Fire TV out of the box and
works better on it than any other protocol. Unfortunately, there aren’t
many apps that use the protocol. Amazon Fling can be used to send streams
from a device on the same network to a Fire TV, and it can be used to
control playback remotely. Fire TV devices have a built in media player
capable of receiving Amazon Fling streams without needing a sister app
installed, but Amazon Fling allows developers to remotely install their apps
on the Fire TV if necessary. It also supports other interesting
interactions that the above protocols do not support. One such capability is
demonstrated in a karaoke app that can use a smartphone as a microphone
through the Amazon Fling protocol.
Miracast
Mircacast is an open protocal for sending video from one device to another.
It is best to think of it as “HDMI over WiFi.” It can only be used to
mirror the entire screen of one device to another device and should not be
thought of as a “casting” protocol like all the ones mentioned above. It
is usually implemented at a hardware or operating system level, instead of
within an app. A key difference is that Miracast makes a direct connection,
using WiFi-Direct, between two devices. It does not use the network that the
two devices are connected to at all. For this reason, many devices
receiving a Miracast connection will completely lose internet access.
Miracast is often heavily influenced by a device’s hardware, which is why
there is often incompatibility between manufacturers. Miracast is also being
abandoned by many devices and operating systems, including Android, in
favor of the casting protocols mentioned above.
The Fire TV supports Miracast out of the box, but as mentioned,
compatibility with smartphones, tablets, and computers is heavily dependent
on the manufacturer’s implementation. The Fire Phone, Fire HD 8, Fire HD 10
, and Fire HDX tablets are compatible with the Fire TV and result in the
best experience because Amazon ensures compatibility. All devices running
Android 4.2 through 5.x should also be compatible with Miracast on the Fire
TV, but it’s hit or miss with some manufacturers. Devices running Android 6
and above have dropped Miracast support unless you root the device and
manually add it back in. Miracast support is present with Windows 8.1 and up
, but again, compatibility is dependent on hardware, specifically the device
’s graphics card. | a******t
发帖数: 100 | |
|
