The Reigning Champ

I love AirPlay. I can take a picture, download a song or find a cool YouTube video and instantly throw it up on my big screen, courtesy of AirPlay and my AppleTV. With my iPad (or a Mac running Mountain Lion), I can mirror the entire screen on my 50-inch plasma at home or 80-inch Sharp in one of my client’s conference rooms. AirPlay is definitely one of the cool things that keeps me buying iOS devices.

Convenience plummets when friends or colleagues try to share content with an Android or Windows mobile device, everyone has to huddle round a 4-inch screen or the device needs to get passed round the room in order to view the intended content. There are two imminent solutions for non-Apple devices: MHL (wired) and Miracast (wireless). We’ll be discussing MHL in another article.

What is Miracast?

Miracast allows user to do things like view pictures from a smartphone on a big screen TV, share a laptop screen with the conference room projector in real-time, and watch live programs from a home cable box on a tablet. All this without connection to a Wi-Fi network. Miracast uses the existing 2.4GHz Wi-Fi connection to negotiate a 5GHz Wi-Fi Direct connection specifically for the streaming of video.

Contrary to popular belief, Miracast is not a technology: it is simply an interoperability test program and brand that allows the seamlessly display of video between devices, without cables or a network connection. Devices that pass this certification testing can be referred to as “Miracast devices”. Miracast certification is based on the Wi-Fi Alliance Wi-Fi Display Specification, which is the underlying technological specification developed by Wi-Fi Alliance members.

Miracast builds on Wi-Fi Direct, which is an interoperability program that allows devices to connect to each other without first having to join a traditional Wi-Fi network. Currently, Wi-Fi Direct is typically used in mobile phones, cameras, printers, PCs, and gaming devices allowing them to connect to each other directly to transfer content and share applications quickly and easily. To date, adoption has been very slow. Maybe Miracast will change all that.

Wi-Fi Direct is one area where non-Apple devices will have an edge over AirPlay, as AirPlay not only requires the mobile device to be connected to a wireless network. That said rumors of “AirPlay Direct” are rife.

Content Support

Miracast supports the H.264 video codec for high-definition video. It supports the Constrained Baseline Profile (CBP) and the Miracast-specific Constrained High Profile (CHP), at levels ranging from 3.1 to 4.2. HDCP (High-bandwidth Digital Content Protection) 2.0/2.1 is also supported, which is a wireless version of the familiar HDCP used with wired devices (e.g. over HDMI). This means users will be able stream premium content such as feature films and other copy-protected content.

For audio, Miracast supports a number of Linear Pulse-Code Modulation (LPCM), Advanced Audio Coding (AAC), and Dolby Advanced Codec 3 (AC3) modes. Unfortunately, audio-only devices are not part of the Miracast certification program: two points to AirPlay.

Wi-Fi-challenged Devices

Clearly, not many people want to buy a new SmartTV just to support wireless streaming; although, at HomeToys we do believe it’s an admirable excuse! While future set-top boxes are likely to have Miracast certification, if you have no other use or desire for a set-top box, it’s a waste of money and power. Fear not, Miracast may be used on devices without embedded Wi-Fi through the use of a Miracast-certified adapter that supports an interface such as High-Definition Multimedia Interface (HDMI) or Universal Serial Bus (USB).

Who’s On-board?

Plenty of chip makers have already signed up, including: Intel (WiDi 3.5), Broadcom, Marvell, MediaTek, Ralink, Realtek, Qualcom, Nvidia. According to the Wi-Fi Alliance, the first consumer-based products certified include the LG Optimus G smartphone, Samsung Galaxy S III smartphone and Samsung Echo-P Series TV. Oddly, none of these shows up under the list of Miracast certified devices on the Wi-Fi Alliance’s certified product list.

No doubt many other vendors are rushing to certify products before the holiday shopping season.


I’m a big proponent of open standards and Miracast could provide the solution for streaming video for non-Apple devices, but it could be too little too late. While this may be great in the boardroom, the omission of audio-only support appears to be a massive oversight on the Wi-Fi Alliance’s part and only strengthens AirPlay’s position. While companies like DTS are adding support for audio over Wi-Fi with Play-Fi, it just complicates consumers’ lives: one new technology for video and another new technology for audio. With an iOS device, all that’s required is a $99 AppleTV (for video) and an AirPort or AirPlay-equipped receiver or speakers. With virtually every receiver manufacturer and many portable speaker manufacturers supporting AirPlay, it’s an easy sell.