QuickTime X:重建播放器和后端

Apple's QuickTime has been around long enough to be called venerable. I remember seeing the first postage-stamp size videos and wondering how long it would be until the video could be played full screen.

花了不到两年的时间.

Fast forward a few years and Apple was showing off movie trailers, 通过渐进式下载, but it was a few years again until the movie trailers were full screen.

Go forward a few more years, and Apple was advocating streaming (and high-definition content) via H.264, hinting—pun intended—at streaming the same images full screen, but it server software was still only streaming in less than full-screen windows.

在这整个过程中, even when Apple made the move from the PowerPC to the Intel chip, the QuickTime technology—both on the server and the desktop—remained static.

这要归功于一款电子产品的问世——iPhone, which has now sold over 40 million units—to force an update of QuickTime on the desktop as well. Apple built a version of QuickTime for the iPhone and iPod touch that allowed viewing of streaming content via HTTP.

今天, 然而, at Apple's Worldwide Developers Conference (WWDC) in San Francisco Apple announced it had both rewritten the code for its desktop QuickTime application—renaming it QuickTime X—based on the iPhone QuickTime technology. 除了, the company has added a few features to its server software as part of an update to its OS X operating system.

“我们正在使用一种叫做HTTP流的新技术,”贝特朗·塞莱特说, senior vice president of software engineering at Apple Inc.. “它适用于任何服务器. Since we had such a change on the backend, we decided to change the look of the player as well."

While HTTP streaming has been around for quite some time, Apple's move to HTTP streaming means that all the major streaming servers will now have HTTP streaming ability.

Serlet's demonstrations focused on the desktop QuickTime X application during today's keynote.

"As soon as I start playing a QuickTime file, the controls and titlebar fade away. 当我想回去的时候, 它们会渐渐消失,”贝特朗·塞莱特说, describing the visual elements of the new QuickTime X player.

"Another great feature is the ability to trim and share my video,”塞尔雷说. "I get a visual timeline and can grab ends of the clip region and trim it right down for easy export to MobileMe, YouTube和其他网站."

Part of the reason the new player is possible is thanks to Safari, 苹果的浏览器, whose version 4 recently passed that Acid 3 WWC compatibility test with 100% compatibility (compared to Internet Explorer 8's 21% compatibility).

"Safari 4 is shipping for Leopard, Tiger, and Windows today,”塞尔雷说. "Safari 4 also has crash resistance in our new operating system. We feel browser plugins are primary cause of crashes in the Mac OS X operating system, so Safari 4 lets the plugin crash without losing your browser window."

Safari 4 also takes advantage of the Macintosh's hardware acceleration, thanks to QuickTime X and something Apple is dubbing OpenCL.

"The way to use GPU power is OpenGL,”塞尔雷说, "but we want to move beyond that. We've devised a technology called OpenCL and have decided to make it an open standard.All the top manufacturers of graphics cards are involved."

A final reason for hardware acceleration in the new QuickTime X architecture is Apple's approach to multi-threaded code. 正如我们几个月前与英特尔和惠普讨论的那样, the newer Intel Nehalem architecture provides a way for threads to be dynamically allocated depending on need, and Apple appears to be exploiting this capability as well.

“多线程代码真的很难，”Serlet说. ”实例, threads in our current operating system (Leopard) don't disappear when an application is idle. 在我们的新操作系统中, an application may use more threads but give them up when the application is idle."

在iPhone前端, the video editing tools could very well be a part of QuickTime on the iPhone in a future release, since the code base isnow similar between QuickTime on the iPhone and QuickTime X.

“我们一直在跟踪HTML 5标准,斯科特·福斯特尔说, 苹果iPhone软件高级副总裁, "and now we're adding support for new standards like audio and video tags to the iPhone, 以及完整的HTTP流."

[更新:在今天的主题演讲结束时, Phil Schiller, 苹果全球营销高级副总裁, announced the new iPhone 3GS - the S stands for "speed" - with video capture, editing and uploading capabilities based around the same QuickTime architecture.]

回到QuickTime X前面, Serlet也这么说, 为了得到QuickTime X, 用户将需要从Leopard (OS X 10)升级.5)升级到新的操作系统雪豹(Snow Leopard, OS 10).6). While Apple has previously charged $99 - $129 for the upgrade, Serlet said that a reduced upgrade price will be in force for current Leopard users.

所有Leopard用户的升级费用为29美元,”塞尔雷说, "and $49 for a family pack upgrade for up to five computers."

QuickTime X和OS X 10.6 will be available in September, 2009, while the iPhone 3.0固件更新将于2009年6月17日提供.