Quote:
Originally posted by oferlaor
GmanAVS,
You're not just thinking out of the box, you're in another box somewhere in unknown space...
You're talking about the frequency of the power input, but the source signals we're receiving are 50Hz or 60HZ regardless of what the power frequency is. These are the frequencies that PAL and NTSC are using and they will not change using a power frequency converter. |
Thank you for enlightening me, space can be a lonely place!
I just spent the past 2 hour reading up on synch rates, PAL/NTSC/FILM frame rates, theoretical and practical conversion from one to another and the ideal display refresh rates associated with those standards. I found some interesting forums/threads addressing your issue (or may I say vigorously debating it! hehehe, different forums same attitudes).
Now I understand! (well I guess just a little more than before...)
Seems to me you have only one option, to buy seperate HT systems and displays to match your source signal!
It is my understanding now, that you could also go the "signal conversion" route, but even if you have the broadcast editing hardware and software to achieve your goal and have the outgoing video resolution and frame rate for each type of broadcast to appropriately match you displays native one, without knowing how the
master source material was recorded (what type of equipment, standard and rate) you will always be at the mercy of leaving it to the hardware and software to generalize and compensate when a frame rate conversion occurs.
I guess the bottom line is what is the lesser evil and what can you live with? Judder effect, blinking effect, loss of definition or added artifacts.... all best summarized by this laser and plasma display engineer "groyal" in the
www.videohelp.com/forums
Quote:
1) Field reordering (a' la SelectEvery(bunch,pattern)). Intuitively the simplest approach, but practically impossible because each field represents a different instance in time. It's extremely difficult to insert copies of fields at regular intervals to make up the rate differential while keeping the top/bottom relationship (and therefore the presentation order) of the surrounding fields intact. The visual effect is a kind of temporal precession, or cyclical vibration, that looks like Benny Hill's version of the Ministry of Silly Walks.
(2) Frame synthesis (a' la ChangeFPS()). This is similar to what hardware converters do, except the new frames are averages rather than motion-compensated interpolations. The visual effect is a blur (more like a smear) in the leading edge of moving objects with a wake following the trailing edge, with distortion proportional to velocity. A sports clip is probably the worst-case scenario for this method, but I don't see why it wouldn't work for a genre that is less kinetic.
(3) Video as Film (a' la pulldown). In essence, this shifts the burden of rate conversion to the DVD player which has on-board means to perform an NTSC telecine (film to video) operation. The visual effect is that treating PAL like film makes it look like film. Field-based video blurs moving objects along the leading edge by presenting it in different positions during the frame interval, and along the trailing edge by the object's movement during the field interval. When you drop one of the fields the leading-edge blur is eliminated but the trailing-edge blur is preserved, lending an unexpected but not objectionable "cine" look to the clip as a whole. |
