As tablets and smartphones continue to surge in popularity, they have become yet more source components that many people would like to connect to their home theater systems. Peruse the features list for a new, smart (i.e., networkable) HDTV, Blu-ray player, HTiB, and the like, and you may encounter some unfamiliar terms. Abbreviations like DLNA, MHL, NFC, and WiDi are popping up everywhere, as manufacturers continue to explore new ways to improve connectivity between traditional AV products and mobile devices. The myriad options can be confusing even for those of us who attend every trade show and see every demo, so here’s a basic primer to explain some of terms you might encounter. This piece focuses specifically on the technologies that are becoming common in HDTVs to facilitate video and audio sharing.
DLNA is likely the term most familiar to our audience, as it’s now available in a large percentage of the smart A/V products released to the market. DLNA stands for Digital Living Network Alliance, which is actually the name of the non-profit alliance of companies that formed this standard for media transmission that is based on the broader UPnP (Universal Plug and Play) standard. DLNA allows for content streaming over a wired or wireless IP-based network. All networkable products that bear DLNA certification should be able to talk to one another, as long as they are on the same network. DLNA-certified products consist of digital media servers that contain the files you want to play and digital media players or renderers upon which you want to play the files. Sometimes a product can be both a server and player.
In your home theater ecosystem, your tablet, smartphone, computer, or network attached storage (NAS) device would be the DLNA server, and the TV (as one example) would be the playback device. You may have to install some type of DLNA application on your server device, of which there are many. I typically use AllShare on my Android tablet and PLEX on my MacBook Pro laptop. The app will assemble the media files stored on your server device and present them in a recognizable way to the playback device. You should see the DLNA app listed as a source within the TV’s media-sharing function; click on it, browse and select the content you want, and hit play. Playback quality is contingent on many things: the quality of the source files, the quality of the video processing within the TV, and the speed and reliability of your network. File compatibility varies per manufacturer. Some choose to support a wide variety of file types; others only support the basics required by DLNA.
Almost every major CE player is now part of the DLNA, which is why the technology is currently the ubiquitous option on our smart AV devices. The notable exception is Apple, which prefers to use its own AirPlay technology for video and audio distribution over a network. I don’t know of any HDTV that has built-in AirPlay … at least, not yet. While Apple devices are not inherently DLNA-certified, you can add apps like the above-mentioned PLEX or XBMC to get DLNA functionality on your Mac computers and/or iOS devices.
Mobile High-definition Link is designed to provide an easy way to physically connect your tablet or smartphone to a TV or other video playback device. A wired MHL connection supports the transmission of up to 1080p/60 video and high-resolution 7.1-channel audio between compatible devices. Both the portable device and playback device must be MHL-compatible. MHL support is integrated into a lot of new Android smartphones and tablets (again, no iOS devices). On the home theater side, MHL is not currently as ubiquitous as DLNA, but it is starting to appear on growing number of HDTVs, AV receivers, video switchers, and other playback devices. You can browse the current list of compatible products here.
Currently, MHL support is built into the HDMI ports on AV products. Take a close look at your TV’s HDMI inputs, and you may find one that has an “MHL” beside it. That means you must connect your MHL smartphone or tablet specifically to that port, which often includes the ability to charge the connected device so that you don’t have to worry about the battery dying during playback of a three-hour movie. You may also be able to control the connected device using your TV’s remote. Connecting the tablet or smartphone to the TV requires a special adapter MHL adapter cable, which you can likely get through Best Buy, RadioShack, and many e-tailers. Once your mobile device is connected via MHL, it basically turns your TV screen into a giant replica of your mobile screen, allowing you not only to access media files on the device but also to play games, surf the Internet, etc.
Roku employs MHL technology in its Roku Stick streaming media player; the Stick is the size of a USB flash drive and plugs directly into an MHL-compatible HDMI port on your TV or AV receiver. Oppo’s BDP-103 also sports an MHL-compatible HDMI input to accept a Roku Stick or similar device.
Because MHL uses a wired connection, you don’t have to worry about the reliability issues that can accompany wireless streaming. Quality depends on the source files, as well as the video processing within the playback device if it must do upconversion. MHL recently announced the 3.0 spec with double the bandwidth to support an Ultra HD resolution and wider color gamut, among other benefits.
WiDi / Miracast
WiDi allows you to share content between devices using a direct wireless link, so you don’t need to have your own network in place the way you do with DLNA. WiDi was developed by Intel and is integrated into Intel-based PCs, as well as TVs from Samsung, LG, and Toshiba (adapter products also exist to add the functionality). WiDi supports the transmission of up to 1080p video and 5.1-channel audio. Not only can you share media content to be displayed on your large TV screen, but you can view other PC applications, too. The Intel WiDi Widget allows you to display separate things on the PC and TV at the same time.
Miracast is a similar technology that can link two devices over WiFi Direct and is available on a wider variety of products. The newest version of Intel WiDi (v3.5) is now based on and compatible with Miracast, so the two technologies have essentially merged. Many people consider Miracast to be Android’s answer to AirPlay; all smartphones and tablets with Android 4.2 or later are Miracast-enabled, and the technology is finding its way into a growing number of HDTVs, Blu-ray players, and streaming media players. As the name suggests, Miracast allows you to mirror the mobile-device screen on your TV screen, as well as stream media files; it supports 1080p video and LPCM, AAC, and AC3 audio.
If you’ve ever used the “swipe” function within the iOS/Android control app for your smart TV, you’ve seen Miracast in action. Panasonic’s Swipe and Share, as an example, is integrated into the company’s VIERA TV Remote app. Once the app is installed on your Android or iOS device, you can cue up a media file and then swipe or flick it off the screen to a network-connected Panasonic TV, where it begins to play simultaneously. You can also bring content (like Web pages) back from the TV screen to the mobile device. Samsung’s Swipe-It and Sharp’s Sharp Beam apps offer similar functionality.
No, we’re not talking football; we’re talking Near Field Communication. You’ve no doubt seen the Samsung phone commercials where they touch the phones together and exchange data. That’s NFC, which establishes a short-range wireless link to exchange information between devices placed within about an inch of each other. NFC can have lots of applications in our daily lives, providing a quick way to exchange contact information, pay for food or tolls, or get more info off of an advertisement.
In the AV realm, NFC is starting to appear in TVs from companies like Sony and LG. It’s designed to speed up the connection process between the tablet/smartphone and the TV, and to then allow for media sharing via another platform like Miracast. I just encountered it for the first time during my review of the LG 55LA7400 LCD TV. You can attach a small NFC tag to the TV and download LG’s Tag On app to your NFC-compatible device. You then do a one-time pairing procedure to enable NFC communication. The app also facilitates media sharing.
That’s our rundown of the hottest trends in HDTV connectivity. Have you tried any of them? How do you prefer to connect your mobile device to your TV? Share your experiences in the comments section below.
By Adrienne Maxwell, HomeTheaterReview