This is going back a ways, but here's my remeberances regarding GOP: 1) there are settings for gop as you have noticed 2) i don't think any of us working on it in the early days had the mpeg-knowhow to tell if they worked or didn't 3) i do seem to recall a scene-change option, but it's not in our current documentation (it may be an extra parameter to 0x97 or 0xc5.. it may have been in a press-release from conexant or something.
perhaps add that to the hauppauge question list? i'd appreciate it if those who can test these things did :) i'll help with some sample code if you need. Also, i'll start a new thread to try and get some recommendations going. Why waste HD space? :) -tmk --- Cory Papenfuss <[EMAIL PROTECTED]> wrote: > Hey all... I've just recently come across 'gopdit' > as a potential > alternative to 'GOPchop' for lossless mpeg2 editing. > My experience has > implied to me that the ivtv driver/cards don't have > an exceedingly high > quality/bitrate ratio. I've usually encoded at a > high bitrate and then > reencoded down with 2-pass, etc to get higher > quality/bitrate. So a few > questions maybe someone can answer on the ivtv > cards: > > - Can it use an intelligent variable GOP structure? > The streams I get are > a constant (IBBPBBPBBPBBPBBPBB?) length and > structure. Something like a > 'detect scene change' to add an I-frame, or possibly > restart with a new > GOP? > > - I looked through the firmware API and saw > references to open/closed > GOPs. Does the chip actually honor this and produce > more intelligent open > GOP streams? What's the default setting for this? > I'm thinking that > maybe open/closed GOPS and such might be why people > are getting different > post-processing results with differnent MPEG stream > types in the driver > (DVD, TS, PS, etc). > > - Would it make sense to have an 'edit-friendly' > mode vs. a > 'burn-friendly' mode to the driver? Basically, I'm > thinking that for > recordings with editing in mind, a higher bitrate > with closed-GOPs might > be worthwhile. For direct master to DVD with > no/minimal post-processing, > an open-GOP structure could produce better quality. > > Feel free to expose my continued ignorance in > these things... I'm > trying to figure out how to get the most out of the > system. There's a > tremendous amount of misinformation and "magic > formulas" people have > heuristically found "works for them" WRT MPEG2 > recording/editing. It'd > sure be nice to figure out things like why sync > breaks, PTSs change, > quality/bitrate is poor, etc... :) > > -Cory > > ************************************************************************* > * Cory Papenfuss * > * Electrical Engineering candidate Ph.D. graduate > student * > * Virginia Polytechnic Institute and State > University * > ************************************************************************* > > > > ------------------------------------------------------- > This SF.Net email is sponsored by: IntelliVIEW -- > Interactive Reporting > Tool for open source databases. Create drag-&-drop > reports. Save time > by over 75%! Publish reports on the web. Export to > DOC, XLS, RTF, etc. > Download a FREE copy at > http://www.intelliview.com/go/osdn_nl > _______________________________________________ > ivtv-devel mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/ivtv-devel > ------------------------------------------------------- This SF.Net email is sponsored by: IntelliVIEW -- Interactive Reporting Tool for open source databases. Create drag-&-drop reports. Save time by over 75%! Publish reports on the web. Export to DOC, XLS, RTF, etc. Download a FREE copy at http://www.intelliview.com/go/osdn_nl _______________________________________________ ivtv-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ivtv-devel
