On Thursday 28 October 2004 01:45, Steven M. Schultz wrote: > > The frames that I feed to mpeg2enc are actually not interlaced, they are > > ordinary 'progressive' images. But since I use png2yuv to generate an > > Ok - that's what I figured. Now to interlace that you need to take > the "top" field from frame #1 and the "bottom" field from frame #2! > > It sounds like you're taking the two fields from the same frame - the > top lines of frame #1 and the bottom lines of frame #1. That's not > how interlacing needs to be done (if I'm not totally off base - and if > I'm spouting off incorrectly someone will let me know I'm sure ;)).
No, you're right. Perhaps, or not. It all depends on one thing I'm not able to remember seeing in this conversation: Dik, what are you generating? Your choices are these: 1: 50 full-resolution images per second. 2: 25 full-resolution images per second. In case 1, Steven is correct, you should take all odd-numbered (if starting at 1) lines of image 1 and put them into the top field, then all even-numbered lines of image 2 and put them in the bottom field. This is what the purists call an interlaced stream. In case 2, however, you've got to do the same thing people do when they convert wet film material into PAL: Take all odd-numbered lines of image 1 (I'm deliberately avoiding "frame" here, and in point 1.) and put them into the top field, then all even-numbered lines of, still, image 1, and put them into the bottom field. The purists seem to prefer not to call this an interlaced stream, as the fields in fact represents the same point in time. It's how all 24 fps movies are converted into PAL and then broadcasted, though. 3: Something completely different. In case 3: What? :) /Sam ------------------------------------------------------- This SF.Net email is sponsored by: Sybase ASE Linux Express Edition - download now for FREE LinuxWorld Reader's Choice Award Winner for best database on Linux. http://ads.osdn.com/?ad_idU88&alloc_id065&op=click _______________________________________________ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
