Differences between version 14 and predecessor to the previous major change of DVDVideoTerminology.
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| Newer page: | version 14 | Last edited on Monday, July 13, 2009 3:10:41 pm | by LawrenceDoliveiro | Revert |
| Older page: | version 12 | Last edited on Monday, July 13, 2009 2:38:40 pm | by LawrenceDoliveiro | Revert |
@@ -1,7 +1,7 @@
Some of the more esoteric terms and concepts you may come across in [DVDVideo].
-A ''packetized elementary stream'' (PES) is just an [MPEG] stream. "Packetized" simply means that the data for each stream is broken up into blocks which are
interleaved (''multiplexed'') together in the file. In DVD-Video, these packets are grouped together into ''packs'' of 2048 bytes, the same size as a sector on the disc. Packs are in turn grouped together into a "VOBU" (Video Object Unit): this always begins with a pack for the navigation stream, followed by packs for the other streams (video, audio, subpicture).
+A ''packetized elementary stream'' (PES) is just an [MPEG] stream. "Packetized" simply means that the data for each stream is broken up into blocks which can be
interleaved (''multiplexed'') together in the file. In DVD-Video, these packets are grouped together into ''packs'' of 2048 bytes, the same size as a sector on the disc. Packs are in turn grouped together into a "VOBU" (Video Object Unit): this always begins with a pack for the navigation stream, followed by packs for the other streams (video, audio, subpicture). Thus, the multiplexing happens between packs in a VOBU, and the VOBU is the smallest unit that a player/decoder can work with at once
.
One or more consecutive VOBUs make up a ''cell''. This is the basic unit of playback in DVD-Video. A cell can have associated program instructions in the virtual machine language, for example telling the player to keep looping the same cell, or jump to another cell.
The cell structure is used, among other things, to define ''parts of titles'' (PTTs), which ordinary users know as "chapters". Why they couldn't just call them chapters in the spec, I don't know...
@@ -12,9 +12,9 @@
The ''first program chain'' (FPC) is a special PGC that contains commands that are executed when the disc is inserted into the player. This typically contains a command like "jump to main menu", or perhaps "jump to copyright warning sequence", which in turn jumps to the main menu.
!Navigation Stream
-The navigation stream contains two kinds of packets: ''presentation control information'' (PCI) and ''data search information'' (DSI).
+The navigation stream contains a ''[system header|http://www.mpucoder.com/DVD/sys_hdr.html]'' plus
two kinds of packets: ''[
presentation control information|http://www.mpucoder.com/DVD/pci_pkt.html]
'' (PCI) and ''[
data search information|http://www.mpucoder.com/DVD/dsi_pkt.html]
'' (DSI).
The PCI contains button and action definitions and subpicture highlight settings--remember that the subpictures themselves are stored in their own streams.
The DSI contains offsets to preceding and following VOBUs at various predefined time differences, used for trick play (scan forward/backward) functions.
