halbert@ucbvax.UUCP (Dan Halbert) (04/16/84)
Re: All this discussion of conversion of television formats: I have noticed, while watching snippets of European television rebroadcast on US NTSC television (usually on news interviews), a non-smooth conversion effect. Every few seconds a frame will appear to be held for an extra long time, and then the following frame will appear jerky, as if one or more have been missed. The previous articles discussing PAL to NTSC conversion describe methods which would not seem to produce this effect. Am I seeing an artifact of a different (poorer) conversion process? Or is this perhaps an artifact of the transmission method, with frames being dropped and previous frames held because of transmission errors or a shared data channel? --Dan Halbert, ucbvax!halbert
msc@qubix.UUCP (Mark Callow) (04/18/84)
> I have noticed, while watching snippets of European television > rebroadcast on US NTSC television (usually on news interviews), > a non-smooth conversion effect. Every few seconds a frame will > appear to be held for an extra long time, and then the > following frame will appear jerky, as if one or more have been > missed. This has *nothing* to do with the conversion process. It has to do with poor transmission lines. It can happen on OB's within the US and is often seen on sportcasts. The incoming signal (to the studio) is being digitally processed. If a field fails to arrive in time, the equipment keeps displaying the previous field, which is held in a field store, until some new information arrives, hence the effect you see on the screen. Since the sound is coming over a different channel that may not be affected. -- From the Tardis of Mark Callow msc@qubix.UUCP, decwrl!qubix!msc@Berkeley.ARPA ...{decvax,ucbvax,ihnp4}!decwrl!qubix!msc, ...{ittvax,amd70}!qubix!msc "I'm a citizen of the Universe, and a gentleman to boot."