|
I am no expert, but to my understanding:
PSEUDO-PROGRESSIVE:
It really is interlaced, but What we have been calling Pseudo-progressive (24 fps film to 60 fields/sec) is where during step forwarding, we see every 5th field an exact (or with some minimal noise) repeat of the 4th field. Pixel comparing Line doublers can detect this repeat pattern, throw away the repeated info and assmble the original 24 film frames back.
These 24 frames are then displayed as 60 full frames (480 lines of res; some frames displayed two times and some displayed 3 times on a 60 Hz display) on progressive displays. (One can go one step further, but I don’t know how to achieve it and verify it, is to display these 24 frames displayed 3 times each for a 72 Hz set.)
PROGRESSIVE:
It really is interlaced, but What we have been calling Progressive DVD is where only the original 24 frames are recorded as 48 fields but with an instruction to repeat every 4th field to get the 5th field to match with the 60 Hz NTSC frequency.
FIELD AVERAGED INTERLACED:
It really is interlaced, and what we have been calling as Field Averaged Interlaced is where 24 film frames have been changed into 60 fields without any repeat pattern. Obviously, each video field contains info from more than one film frame. It is not a must that PAL to NTSC converted video has to be field averaged, but 99% of PAL to NTSC DVDs that we see are like that. Some of EVP Hindi DVDs that are not progressive, you see that every 5th and 6th step is the same. This is a clear indication of 25 frames per sec changing to 60 fields per sec.
FILM—PAL—NTSC conversions:
Film to PAL coversion involves 24 fps changing to 50 fields per sec. Industry accepted practice is to run the film faster at 25 frames per sec (4% speed shift; what we have been calling Progressive DVD).
But, Indian Film to PAL conversions try to compensate for this extra frame.
Some, by repeating every 25th field. Present day line doublers don’t anticipate this and hence can’t assemble the original film frames back. Perhaps one day some line doubler will work for this situation as well.
Some, by averaging out 24 frames into 50 fields. No line doubler will ever get the original frames back from this.
Now converting from PAL to NTSC can again be either by repeating certain fields or by averaging. Most of the times 'Film to PAL and then to NTSC' transfers end up being field averaged in one of the stages or accumulate so much video noise that no repeat pattern is visible or detectable. 6 or 7 EVP DVDs are an exception.
Direct Film to NTSC and Field Averagged:
Just like 24 fps Film to 50 fields/ sec PAL can be either field averaged or every 25th field repeated, 24 fps Film to 60 fields/sec NTSC too can be either field averaged or can have every 5th field repeated.
Mostly, direct Film to NTSC cine-tel has repeat field pattern and is not field averaged.
NTSC to NTSC copy:
This too can be copied field by field or field averaged. Mostly, this too is done right, field by field, and not field averaged. Not even on chepest VCRs. Even in field by field copied VHS you may not detect any repeat pattern due to excessive video noise (nth generation copies).
OLD Indian Film VHSs:
Many early Indian Film VHS tapes have repeat field pattern visible; a sign of direct film to NTSC tele-cine. Later, Indian Film VHS’s didn’t have this repeat pattern. It is well known, Indian VHSs were mostly done for PAL countries and NTSC copies were converted from PAL.
Rana
P.S.
Arsh, I haven’t seen original YRF Saathiya. Is it Direct Film to NTSC cine-tel?? Is it Pseudo-prog??
I have 2in1 Saathiya-DKR. They seem like YRF sourced, but Saathiya is Field Averaged.
Edited By rana on 1064349061
|
Login 
Register
FAQ
Search
Maybe a mixture of brass and copper but definitely not gold!