On Thursday 28 October 2004 17:57, Steven M. Schultz wrote: > > This is > > what the purists call an interlaced stream. > > It's not just what "purists" call an interlaced stream - it is an > interlaced stream ;)
"Purist" in the nicest possible way, of course. Yes, it's interlaced. > > The purists seem to prefer not to call > > this an interlaced stream, as the fields in fact represents the same > > point in time. > > That's because it's not an interlaced stream :) It could be. It depends on one's intentions. Technically, I believe we could agree that it is, in fact, a progressive stream distributed in an interlaced container. (Which doesn't make much sense, unless you're distributing the frame via PAL/NTSC/SECAM broadcast, which, per definition, can not cope with progressive streams. On disk, in an MPEG file, the matter is completely different. It is my belief that I'm talking about the former case, and you about the latter.) (And that parenthesis can be interpreted as totally irrelevant in this case. So be it, then. My TV captures are still stored and transfered to and from my MJPEG card as interlaced streams, regardless of whether they contain progressive frames or not. I make them progressive when I send them to the MPEG encoder.) > The encoder sets the 'progressive frame' flag in the MPEG header and > the structure to 'picture structure: frame picture' - this > tells the decoder that the two "fields" came from the same point in > time - i.e. it's a progressive image. You're correct. The image is progressive, and I said nothing else. This doesn't say it can't be distributed in an interlaced stream, though. Aw, what the heck, we're talking about slightly different things anyway. You're right, and I believe I'm right too. Agreed? > There's no case 3. Cases 1 and 2 cover all the possibilities - either > the data is interlaced or it is progressive, I can't imagine an third > state ;) Hence the smiley. /Sam ------------------------------------------------------- This Newsletter Sponsored by: Macrovision For reliable Linux application installations, use the industry's leading setup authoring tool, InstallShield X. Learn more and evaluate today. http://clk.atdmt.com/MSI/go/ins0030000001msi/direct/01/ _______________________________________________ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
