PDF《Encoding for HTML5》

1 Encoding for HTML5 Jan Ozer www.

streaminglearningcenter.com [email protected]/ 276-238-9135 Copyright ?

2011 Jan Ozer, All Rights Reserved Producing H.264 ? PDF available on www.streaminglearningcenter.com now ? The HTML5 playback environment ? Producing H.264 ? Producing WebM

2 Copyright ?

2011 Jan Ozer, All Rights Reserved For Additional Reference The material in this presentation was derived from Jan Ozer'

s book, Video Compression for Flash, Apple Devices and HTML5. For further explanation of the concepts presented in this presentation, check out the book at bit.ly/ozerbook1 Copyright ?

2011 Jan Ozer, All Rights Reserved HTML5 Playback Environment ? HTML5 penetration C Desktop ? HTML5 codec support

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2011 Jan Ozer, All Rights Reserved Browser Marketshare ? http://www.netmarketshare.com/browser-market- share.aspx?qprid=2&

qpcustomd=0 Copyright ?

2011 Jan Ozer, All Rights Reserved HTML5 Penetration ? As of today, at least 42% of desktops NOT HTML5 compatible ? HTML5 usage MUST fall back to plug-in based technology

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2011 Jan Ozer, All Rights Reserved HTML5 Codec Support ? http://diveintohtml5.info/video.html Copyright ?

2011 Jan Ozer, All Rights Reserved HTML5 Codec Support

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2011 Jan Ozer, All Rights Reserved So: ? HTML5 lets you access about 60% of desktops today (maximum) ? To access those desktops, you'

d have to produce three file versions ? H.264 C Chrome, Safari, IE9 (Chrome going away) ? Web M C Firefox post 3.6, Opera post 10.6, Chrome ? Ogg C Firefox 3.6 and earlier, Opera 10.5 and earlier Copyright ?

2011 Jan Ozer, All Rights Reserved Producing H.264 ? What is H.264 ? What does it cost? ? What are the key encoding parameters? ? How do I customize the file for HTML5?

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2011 Jan Ozer, All Rights Reserved What is H.264? Streamcrest Associates http://www.streamcrest.com/SDF%20Final1.pdf ? Adapted by ISO and ITU ? Telephony/cellular ? TV - consumer electronics ? Computer electronics ? Only codec adopted by top three streaming providers (Apple, Adobe, Microsoft) Copyright ?

2011 Jan Ozer, All Rights Reserved What'

s MPEG-4/H.264 Cost? ? For free Internet video (e.g. no subscription or pay per view), free in perpetuity ? Still technically a licensing obligation, but there are no teeth and no motivation to enforce ? For subscription or PPV, there may be a royalty obligation ? For browsers, encoders and players, there is a royalty (US$5 million max/company/year) ? Check www.mpeg-la.com

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2011 Jan Ozer, All Rights Reserved What is an MP4 file (and what are the variants)? ? .MP4 - official MPEG-4 wrapper ? .M4V - Apple'

s variant for iTunes and devices ? .MOV - H.264 file for editing or QuickTime delivery ? .F4V - H.264 for Flash ? .3GP - (not shown) - phone ? .MPG - H.264 in MPEG-2 transport stream Copyright ?

2011 Jan Ozer, All Rights Reserved H.264 Encoding - Basics ? Profiles and Levels ? Entropy encoding ? I and B-frame settings

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2011 Jan Ozer, All Rights Reserved What are H.264 Profiles? ? Define a set of coding tools or algorithms that can be used in generating a bitstream Copyright ?

2011 Jan Ozer, All Rights Reserved What are H.264 Levels? ? Constrains key parameters in the bitstream, like video bit rate and resolution

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2011 Jan Ozer, All Rights Reserved Profiles and Levels ? Why do they exist? ? Allow device manufacturers to build devices with varying power to support the various profiles ? iPod C low power, Baseline profile ? iPad C more powerful CPU, Main profile ? iPhone 4S C more powerful still, High profile Copyright ?