Mike, The explanation is great! thank you!
But still, the basic principle of video is still displaying a sequence of images (motion picture) with audio sync. Even with GOP, it is still displaying a sequence of images with full frame of first image, then display what's different on the second picture and onwards. Taky ----- Original Message ----- Thats Great! This should be posted on wikipedia. --- In [email protected], Mike Boom <[EMAIL PROTECTED]> wrote: > > At 07:21 AM 10/30/2006, Taky Cheung wrote: > >Isn't all videos are just sequence of images synched up with audio? > > Most video compression schemes these days (MPEG2, H.264, and so on) > work with GOPs (Group Of Pictures) which aren't simply a sequence of > images. A GOP starts with a single frame (an index, or I, frame) that > contains a single picture in all of its detail. The following frames > (B and P frames) contain only information about what has changed > since the last frame, so they require far less data because in video > images typically don't change much from frame to frame. > > An HDV camcorder records using MPEG2 with GOPs, and when you edit HDV > in Premiere you're working in MPEG2 as well (at least in PP 2.0). > That's why playback feels a tad quirky sometimes. The camcorder or > Premiere has to find an index frame before it can figure out the > frames following it. > > Mike Boom > [Non-text portions of this message have been removed] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Adobe-Premiere/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/Adobe-Premiere/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
