The Importance of the File Format for Adaptive Streaming(文件格式对自适应流的重要性)
翻译水平有限,仅供参考
When it comes to adaptive bitrate streaming over HTTP, file format really does matter. The fragmented MP4 (fMP4) file format, first used by Microsoft, is the basis of IIS Smooth Streaming, Adobe HTTP Dynamic Streaming, and two industry streaming standards. fMP4 files have some distinct advantages over adaptive streaming solutions based on MPEG-2 Transport Streams, such as the proprietary HTTP Live Streaming (HLS) format developed by Apple.
当涉及到基于HTTP的自适应流时,文件格式就显得很重要。首次使用碎片化的MP4文件格式(fMP4)的流媒体包括微软平滑流媒体(IIS Smooth Streaming)、Adobe HTTP Dynamic和2个行业流媒体标准。与苹果公司开发的基于MPEG-2 TS流的HTTP Live Streaming(HLS)专有格式的解决方案相比,fMP4拥有一些显著的优点。
HLS is based on a derivative of the MPEG-2 Transport Stream (M2TS), which was developed nearly two decades ago for broadcast TV. On the other hand, the fMP4 file format was specifically designed to address the needs of modern streaming to computers, televisions, and mobile devices. fMP4 offers a number of key benefits over M2TS solutions, such as:
HLS是基于20年前因广播电视而产生的MPEG-2 TS的一种延伸。另一方面,fMP4是专为满足现代计算机、电视和移动设备流播放需求而设计的文件格式。fMP4提供了优于M2TS解决方案的特性。
• Trickplay capabilities (e.g., fast-forward, pause, instant replay)
• Seamless stream adaptation to local conditions
• Reduced storage requirements
• Backwards compatibility with M2TS-based solutions
• Integrated digital rights management (DRM)
• 策略播放功能(如快进、暂停、回放)
• 无缝地自适应本地条件
• 降低存储需求
• 向后兼容M2TS解决方案
• 集成了数字版权管理(DRM)
When Microsoft first developed IIS Smooth Streaming, we built the fMP4 format on Part 12 of the MPEG-4 standard, which defines the ISO Base Media File Format. We released the specification for the fMP4 format under the name "Protected Interoperable File Format" (PIFF). In addition to IIS Smooth Streaming, this format has become the basis for streaming for Netflix, Comcast XFINITY, and two industry standards: the UltraViolet digital-rights management and delivery standard, which based their Common File Format on PIFF; and the upcoming MPEG-DASH (Dynamic Adaptive Streaming over HTTP) standard.
当微软开发平滑流媒体时,我们建立的fMP4格式定义了ISO基本媒体MPEG-4第12标准。我们发布了名为Protected Interoperable File Format" (PIFF)的fMP4格式规范。除了IIS平滑流,这种格式已经成为XFINITY、Netflix公司,康卡斯特和两个行业标准流的基础:UltraViolet的数字版权管理和交付标准,基于其上PIFF的通用文件格式以及即将推出的MPEG - DASH(HTTP动态自适应流)的标准。
Tim Siglin, a well-known digital media consultant and writer with Transitions, Inc., has just released an excellent white paper that explores the fMP4 file format and what it means for the future of streaming video. A unique aspect of this paper is that teams from Microsoft and Adobe worked together with Tim on it, a first-time collaboration that provides hope for a standardized media streaming format in the near future. To get the Adobe perspective on this, please refer to Kevin Towes' blog post.
Tim Siglin是一位知名的数字媒体专家及作者,Inc刚刚发表了优秀的白皮书,其中探讨了fMP4 文件格式以及对未来流媒体视视频的意义。白皮书的独到之处在于微软和Adobe团队首次与Tim合作提出了标准化流媒体。若想从Adobe的角度来了解,请参考Kevin Towes的博客。
To learn more about fMP4 and read the white paper, titled "Unifying Global Video Strategies - MP4 File Fragmentation for Broadcast, Mobile and Web Delivery," please see Tim's blog post.
要了解更多关于fMP4可以阅读名为“统一视频全球战略——用于广播的MP4文件碎片,手机和网络交付”白皮书,请查看Tim的博客。