Differences between version 23 and predecessor to the previous major change of MPEG.
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| Newer page: | version 23 | Last edited on Saturday, January 9, 2010 1:40:26 pm | by LawrenceDoliveiro | Revert |
| Older page: | version 22 | Last edited on Saturday, January 9, 2010 1:13:11 pm | by LawrenceDoliveiro | Revert |
@@ -22,8 +22,10 @@
The drawback with this is, if you try to start playback from some arbitrary point that is not at the beginning of the file, the player has to seek backwards until it hits an I-frame before it can start sensibly decoding the video. Thus, using fewer I-frames improves compression, at the expense of quick random access into the video stream. The [DVD-Video|DVDVideo] specification requires at least one I-frame in just over every second of video.
The sequence of frames starting from an I-frame until the last frame before the next I-frame (in other words, containing all the frames depending in some way on the starting I-frame) is called a ''Group of Pictures'' (GOP).
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+More esoteric details can be found in [MPEGTerminology].
!Licensing
MPEG-1 doesn't seem to be subject to any licensing requirements. MPEG-2 and MPEG-4 are licensed by [MPEG-LA|http://www.mpegla.com/]. It looks like licensing for MPEG-4 is less onerous than for MPEG-2, if only because Microsoft's Windows Media Player doesn't include support for MPEG-2 or DVD-Video playback, unless you pay for a third-party codec or upgrade to Vista Home Premium or Ultimate.
