Google released a Google Cast SDK for its Chromecast media player dongle to let Android, iOS, and Chrome developers build compatible apps and websites.

Since Google began shipping its $35 HDMI stick-style Chromecast last July, it’s been a hot seller, especially compared to the struggling Google TV devices. The device is not a full-fledged media player, but instead lets you wirelessly stream content from the Chrome browser of a desktop, laptop, or mobile computer to an HDTV via its HDMI input. The Chromecast’s Android–derived stack supports streaming content directly from recent versions of Android, iOS, Windows, Mac OS, and Chrome OS, as well as from more than a dozen Web-based content providers.

Chromecast

With the new Google Cast Software Development Kit (SDK), which was previously available as a technology preview, other developers can make now make Chromecast-friendly apps and websites that can be beamed to the big screen. The SDK is initially available with Google Cast APIs for Android, iOS, and Chrome, and supports development with HTML5 and other web technologies.

The SDK lets developers build Chromecast apps or update existing apps that can “cast” video, audio, or screen-sharing content to a Chromecast device without interfering with multitasking on the source device. According to Google, no porting is involved. Instead you simply add the SDK to your existing app to provide the Google Cast UI.

Google Cast sender UI from smartphone (left), and the TV’s receiver UI
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The SDK lets users sync UI response between the source device and the Chromecast. For example, if the user pauses content playing on the TV, the TV interface indicates the pausing of the video, while the source device provides action for resuming playback, says Google.

Stock sender (source) and receiver (Chromecast/TV) menus are provided, along with the ability to customize them. Cast menus on the sender app provide options like letting you choose from multiple nearby receiver devices. The menus include play/pause controls, elapsed time, content duration, volume, and other basics. Receiver UI elements include opportunities for updatable branding and promotional messages, paused messages, as well as elapsed time and duration displays.

Restrictions include the need to keep apps lightweight, and the inability to create new tabs, windows, or popups. All interaction must be done through the sender application, while the receiver UI is limited to informational material. Developers are encouraged to use transparencies, as well as limit UI elements to the lower third of the screen. Only one video element may be active at any time, and video compositing, manipulation, transformations, rotations, or zooming are not supported.

“Cast” icon (circled) appears when receiver is present, and turns color when mobile device is engaged
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Google has supplied “Google Cast Ready” logos for apps and websites, as well as content-specific Cast buttons so users know they can cast material to the TV. The buttons are designed so that they appear when a receiver device is available, and change color when Casting is underway.
 
Chromecast: a “headache” for Hollywood

A Park Associates survey published in October found that 34 percent of Chromecast owners stream video from Hulu to their TV set every day, and 43 percent stream from Netflix on a daily basis. Currently, apps with Chromecast support include Netflix, HBO Go, Hulu Plus, Pandora, YouTube, Google Play (Music, TV, and Movies), VEVO, Red Bull.TV, Songza, Plex, PostTV, Viki, and RealPlayer Cloud.

“Google Chromecast is making it easier for consumers to circumvent screen restrictions,” stated Park Associates direct of Consumer Analytics John Barrett, noting that half the Hulu Chromecast users use the free Hulu service, which is restricted to computers. “Chromecast is giving people in Hollywood headaches right now,” stated Barrett. “All the wrangling over licensing restrictions doesn’t mean much if consumers can simply circumvent them.”

Chromecast is also posing competition to Roku and other streaming media player device vendors. From the start, Google said it planned to license the Chromecast hardware technology to TV and media player manufacturers the way it does with Google TV today. At CES, Roku announced partnerships with TCL and Hisense to integrate Roku technology in their smart TVs.

Other streaming media dongles: Roku, Plair, Biggifi, AirTame
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Meanwhile, Google Chromecast is also facing competition from various Linux- and Android-based dongle devices that offer somewhat similar broadcasting of mobile or PC content to the big screen. These include the Plair, the BiggiFi, and the PC-only AirTame.

 
Further information

The Google Cast SDK is now available in for free download. More information and a video overview may be found at this Google Cast SDK announcement, and more detailed technical information and design guidelines may be found on the Google Cast SDK developer page.