Citation :
Pal-B, G, H, I and D as far as the actual video is concerned, are all the same format. That is: they are all PAL. There is no difference. All use the 625/50 line/field rate..... scan at 15,625 h-lines/sec and use a 4.433618 color subcarrier frequency. The only difference is in how the signal is modulated for broadcast. Thus the B, G, H, I & D designate broadcast variations as opposed to any variation of the video format. PAL-I for example, has been allocated a wider bandwidth than PAL-B, necessitating that the sound carrier is placed 6Mhz above the picture instead of 5.5 MHz above the picture carrier. Thus a PAL-I TV (the United Kingdom for example) will get no sound if taken to the Netherlands for example (PAL-B) if all the TV's tuner is able to decode is PAL-I. (Fortunately, most European tuners support most of the broadcast variations ).
This is why for example, you won't find a standards converter that will convert a video from PAL-B to PAL-I. There's simply nothing to convert.....They are already the same PAL format. There are major differences between PAL-M and PAL-N however, that would require conversion, as the line/field rate and color subcarrier frequencies are different from standard PAL.
|
