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Accessibility/Video Codecs: Difference between revisions
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Accessibility/Video Codecs (view source)
Revision as of 06:25, 21 September 2008
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In theory, given a multiplexing rule, you can put any video codec and any captioning format in any container. However, multiplexing rules don't exist for all codec/container combinations. | In theory, given a multiplexing rule, you can put any video codec and any captioning format in any container. However, multiplexing rules don't exist for all codec/container combinations. | ||
Instead, video codecs tends to have a conventional native container and the choice of video codec dictates the container and audio codec to use. By choosing Ogg Theora as a baseline codec, the native container format is Ogg and the native audio codecs are one of Vorbis, Speex, or FLAC. Gecko embeds an Ogg-specific playback framework called liboggplay. It only supports the Ogg container format. | Instead, video codecs tends to have a conventional native container and the choice of video codec dictates the container and audio codec to use. By choosing Ogg Theora as a baseline codec, the native container format is Ogg and the native audio codecs are one of Vorbis, Speex, or FLAC. | ||
The Flash plug-in effectively provides a specialized playback framework for .flv and .mp4 containers. Gecko embeds an Ogg-specific playback framework called liboggplay. It only supports the Ogg container format. | |||
In theory, different containers also have different conventional timed text formats. MPEG-4 for example supports W3C TimedText, while Flash supports a proprietary CuePoints format (http://www.actionscript.org/resources/articles/518/1/Creating-subtitles-for-flash-video-using-XML/Page1.html) and a simple version of W3C TimedText (http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/TimedTextTags.html). | In theory, different containers also have different conventional timed text formats. MPEG-4 for example supports W3C TimedText, while Flash supports a proprietary CuePoints format (http://www.actionscript.org/resources/articles/518/1/Creating-subtitles-for-flash-video-using-XML/Page1.html) and a simple version of W3C TimedText (http://livedocs.adobe.com/flash/9.0/ActionScriptLangRefV3/TimedTextTags.html). | ||