DLNA , AirPlay , Miracast , Chromecast : How They Work
In an era of devices permanently connected to the network, you might think that it’s never been easier to send content from one to another. Then why do we have three different systems to which it has just added a fourth?
The devices that we use most frequently , from TV to mobile phone , through your PC or tablet , are now always connected to the network , not just the Internet, but often also at least to a local network Wi-Fi. This should allow for a flow of content from one device to another and almost no natural obstacles, but the daily experience teaches us that often it is not so simple: often do not even know they have this functionality available due to obscure trade names , or maybe use the system at the wrong time . Today there are at least three different methods of content sharing , each with a story and a scenario of use different from the other , that if they have recently added a fourth sponsored by Google. The trick is to choose the right system for the right application . So we try to better understand what is AirPlay , Chromecast , DLNA and Miracast and when to use them.
First was the DLNA
The Digital Living Network Alliance is the first attempt to express the consumer electronics industry the potential of a data network in the consumer . We’re talking about a standard developed in 2003 by a consortium promoted by Sony and now includes hundreds of companies, with literally thousands of compatible products. It is a system designed for sharing media files and uses an architecture of client / server , a device acts as a binder content , videos, music , images , which can draw on all the others.
This makes it ideal for example for playback on a TV or a tablet videos that we have on the hard disk of a PC or NAS . Another scenario is what he sees as the TV act as a server to share video recordings with it to other devices. The DLNA server also uses the metadata of the file to build a catalog that facilitates browsing the media library , a feature especially useful for music sharing .
Unfortunately, the DLNA has not had a good historian with regard to the definition of the supported formats , with a discrepancy between those officially recognized and those actually used by users, with the result that for years it was said that two DLNA-certified devices both were able to play the same formats . Today the situation has more or less stabilized , but there may still be differences in terms of features supported .
In a second stage was added the ability to send push content from one device to another , for example, display a photograph from a smartphone to a TV . This mode , which requires the receiving device supports the profile ” renderer ” is less widespread and its implementation is not always so refined . For example, it may be that the TV should be put “listening” before you can receive files , a condition that reduces the immediacy of use.
It is supported by thousands of devices of all types
Theoretically it is extremely versatile
It allows the auto discovery of devices on the network
Require a dedicated server for file sharing
Features renderer less widespread or implemented so cumbersome
It can be used for streaming from app to devices of Internet services
Sharing a library on the local network. Streaming from PC or NAS to other devices .
AirPlay , Apple’s solution
AirPlay is a streaming solution from Apple, originally founded under the name of AirTunes to stream music from iTunes to the Airport Express . With the years has evolved to include video , iOS devices , Apple TV , and at least for audio, third-party devices such as wireless speakers or amplifiers. AirPlay essentially allows you to play audio and video from a PC with iTunes on a Mac or iOS device on an external device via a Wi-Fi network . In this case it is not a file share , but the connection of external devices via the wireless network : the music we’re playing through an app on the iPhone, rather than simply be reproduced with the built-in speaker , is sent to the wireless outdoor speaker .
Same goes for the video, but it works only with the Apple TV: we can start to play a YouTube video on an iPad, and when you press a button to switch to playback an Apple TV to watch them on TV . In this case, the function changes depending on the type of content : a video on the phone will be converted and transmitted via Wi-Fi to the Apple TV as a stream from YouTube, for example, will open directly from the Apple TV.
Another function , added later , is to screen mirroring, which allows you to duplicate the screen of a Mac , an iPhone or iPad via Wi-Fi on a TV using Apple TV. A very useful function to display the contents of an app on the TV , such as the browser or social network . The lag generated by wireless connection (with consequent compression), making it suitable for little app that require real-time interactions , such as video games , but Apple has also implemented a feature that also allows you to use AirPlay to configure your smartphone or tablet as a second screen with some applications.
Overall it is a very simple system to use, where there is nothing to configure, but has a major limitation : it is exclusive of the Apple ecosystem .
Ease of use
Supported by the majority of iOS app
The protocol is lossless audio
It is exclusive of the Apple ecosystem
Only the audio protocol is licensed to third-party vendors
It can be used to share files over a local network
Playing files or streaming content applications from iPhone and iPad to TV or sound systems with Apple TV. Connecting an external monitor to the Mac via Wi -Fi via Apple TV.
Miracast , mirroring becomes ( almost) universal
Miracast is a wireless technology promoted by the Wi- Fi Alliance that is designed to add to smartphones and tablets feature display mirroring, to share the screen with compatible TV. Unlike the DLNA or AirPlay , Miracast does not use a pre- existing wireless local area network , but it uses the Wi-Fi Direct , Wi-Fi version of establishing a one to one direct connection between two devices, in this case, smartphone, tablet TV or PC and a certificate Miracast .
Miracast uses the H.264 codec for encoding and transmission of the video, and the system is able to adapt in function of the conditions of the radio channel . The transmission is protected with WPA -2 the same pattern of traditional Wi-Fi . The configuration is quite more cumbersome compared to the AirPlay feature . Miracast must first be enabled in the settings of the TV is that the source device . So it must be carried out a kind of coupling , initiating a search for devices , or from the source ( in this case it will seek the TV compatible nearby), or on the TV , or, depending on the implementations , on both devices . At this point it is possible to start playback.
Miracast is a system of duplication of the screen and as such allows you to view TV on the entire screen of the device , just as if we were using an HDMI cable , so it is ideal to see how the browser app or social network on the screen of TV . It should be borne in mind that the image will have the same aspect ratio ( and orientation ! ) Screen of the smartphone or tablet with the same status bars or other interface elements . For games it is less usable because of the delay, but with the appropriate app can also be used to play back photos and videos.
A little as is the case for DLNA , also support Miracast is often hidden under different brand names and often the actual implementation of mating, or the activation of duplication varies from manufacturer to manufacturer, and can also be quite cumbersome or source of confusion.
Supported by a growing number of TV from all manufacturers
It is integrated into Windows 8.1
It supports up to 1080p video and (optionally) 5.1 audio
At the moment only supported on Android smartphones and tablets , and Windows PC 8.1
The transmission delay makes it unsuitable for apps like games
Interoperability is not always so “immediate”
Display the Home screen of your smartphone or tablet on your TV. Ideal for browser, magazine , social network, but also photos and movies stored on your smartphone.
Google gets up Chromecast
Miracast , as we have just seen, is a system for screen sharing : on TV we will see exactly pixel by pixel, the display content on your smartphone. But if we wanted to play a video from YouTube or another app ? The duplication in this case is inefficient because it requires a double connection of the source device , which is to receive the video from the Internet, decode it , and then convert the whole image on the screen to send it to the TV : do waste bandwidth, but also of precious battery power. For this reason, Google has decided to make Chromecast , as a concept not unlike Apple’s AirPlay , which uses a USB / HDMI instead of the Apple TV .
Chromecast (currently available only in the U.S.) is a small device based on a simplified version of Chrome OS , which connects to the Wi-Fi local area network and is able to play audio and video streaming ” on the recommendation ” of compatible apps installed on a smartphone or tablet, or on a PC with Google Chrome. Streaming real is actually carried out by the key and not the smartphone that simply sends the address of the stream and the metadata for the screen interface and playback control .
Unlike Apple’s AirPlay , whose support is ” cooked ” in iOS , OS X and iTunes ( on a PC) , Chromecast is multi- platform and compatibility is at the application level . For example, the YouTube app or Play Music (above) Chromecast support on Android that iOS . The experience of use in this case is very similar to that of AirPlay , since the applications are able to automatically detect the presence of Chromecast on the net and all you need is to select the appropriate icon to start playing on TV .
At the moment Chromecast does not support the transmission of local files natively , but there are some apps that enable this function as Avia Media Player or Plex (only from Plex Server). The key Chromecast also does not support DLNA or Miracast .
It is a multi- platform
Ease of use
Low cost of stick: $ 35
It is currently available only in the United States
Streaming of local files currently limited to a few third-party apps
Few applications supported
Viewing on TV streaming service from PCs and apps for smartphones and tablets .
The ideal system does not exist yet
This quick overview shows one thing: when the “universal” solution adaptable to all use cases does not exist. AirPlay is perhaps the most complete solution in terms of functionality if it were not for the fact that detail only works with Apple devices , although there is an open source audio is also used by some app for Android. The DLNA is the perfect way to share files, but the interfaces are often drawn approximately at the expense of the experience of use, and above all does not work with streaming services . Miracast is a replacement of the cable, but despite the work of the Wi-Fi Alliance certification , many manufacturers call their way to functionality, or put it in another menu . Chromecast is another proprietary solution , but has the advantage of being cross-platform and very easy to use , but the media is still limited on the applications side , while the hardware is receiving at the time comprised only the key to Google. At the moment Chromecast also can not replace the DLNA or Miracast. Credit : dday.it