Hi! anopheles wrote:
> In the special case where a single original MPEG for 1 titleset is > 1GB > and dvdauthor (or whatever) slices it into several VOBs each 1GB (max) > then my (limited) reading and some experiments suggest that those particular > VOBs _can_ be joined by cat into a single file and successfully operated on > by dvbcut. > > or have I just been lucky? I think so. In general, dvdunauthor tries to rebuild the file(s) the DVD was made from. If you're lucky, there will be a single file per title (even if it's longer than 1 GB). But I also had the case that a title was split in two files from the beginning, and dvdunauthor didn't join the pieces. > Ref: http://www.mpucoder.com/DVD/vobov.html > This informal doc is ambiguous about VOBs, or overloads the meaning of VOB. > At > one point it says: > > [ quote ] > A VOB file is an MPEG-2 system stream. This means > that it complies 100% with the MPEG-2 system level standard, > ISO 13818-1. > [ /quote ] Well, someone doesn't know their standards there. ;) System streams only appear in MPEG-1 (aka ISO/IEC 11172). MPEG-2 (aka ISO/IEC 13818) replaced them with program streams (which use the same start codes but are syntactically different). A VOB (every VOB) uses MPEG-2 program stream syntax with 2K sized packs (that's exactly one pack per DVD sector). But it's not a program stream in its own right (that is, not a single title or chapter with contiguous timestamps). > But later it admits that a physical VOB file (on the disk) might start at an > arbitrary position: > > [ quote ] > All the content for one title set (VTS) is contiguous on the DVD, but broken > up into 1GB files in the computer compatible file systems for the convenience > of the various operating systems. > ... > The files are broken up without regard to content, which is why it is > difficult to process any file but the first, since it most likely will not > start at a VOBU (start with a NAV pack). The usual split point is at 524,287 > sectors (1,048,574 KB, 1,073,739,776 bytes). > [ /quote ] The split is at least done on a sector/pack boundary, so the MPEG-2 syntactical structure is always maintained. Theoretically, when you cat all the VOBs in a titleset together, the result will be the same as if you had concatenated all the source MPEG files (plus NAV sectors and padding to a 2K boundary at the end of each file). If there was only a single source file, you're done. If not, you'll have to chop the file into pieces again and handle them separately. -- Michael "Tired" Riepe <[EMAIL PROTECTED]> X-Tired: Each morning I get up I die a little ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ DVBCUT-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dvbcut-user
