[résolu] Compatibilité entre normes PAL

Compatibilité entre normes PAL [résolu] - Ecran - Hardware - Périphériques

Marsh Posté le 26-07-2005 à 10:41:25    

Bonjour à tous,
 
je suis à la recherche d'information concernant la norme PAL. Je sais qu'il existe plusieurs types de normes tel que:
- PAL-M au brésil
- PAL-B/G en France
...
 
J'aimerais donc savoir quel est la différence entre ces normes, et si elles sont compatibles entre elles.
 
Toute aide est la bienvenue.
 
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Message édité par nioc_bertheloneum le 27-07-2005 à 13:24:23
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Marsh Posté le 26-07-2005 à 10:41:25   

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Marsh Posté le 27-07-2005 à 13:23:56    

En fait je me réponds à moi-même, au cas où ça pourrait intéresser du monde:
 
http://www.videoequipment.com/access/formats.html:
PAL: Phase Alternation Line. Developed in Germany. Based on the NTSC system, it was modified to avoid color distortion. Broadcast started in 1967.

Basic Parameters       PAL B-G-H    PAL I        PAL D        PAL N        PAL M
line/field             625/50       625/50       625/50       625/50       525/60
horizontal frequency   15.625 kHz   15.625 kHz   15.625 kHz   15.625 kHz   15.734 kHz
vertical frequency     50 Hz        50 Hz        50 Hz        50 Hz        60 Hz
color subcarrier freq. ~4.43 MHz    ~4.43 MHz.   ~4.43 MHz.   ~3.58 MHz.   ~3.57 MHz.
video bandwidth        5.0 MHz      5.5 MHz.     6.0 MHz.     4.2 MHz.     4.2 MHz.
audio carrier          5.5 MHz.(FM) 6.0 MHz.     6.5 MHz.     4.5 MHz.     4.5 MHz.


 
Voici les problèmes qui peuvent être rencontrés:
- http://www.videohelp.com/forum/archive/t265063.html

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.


- http://www.satelitska-tv.com/tv_sistemi.asp

Citation :

marks with different TV sistem for Countres shows the difference in one system and it usually means difference in sound system.
SECAM will be black&white on PAL TV the same as NTSC or no picture at all
 
All this is irrelavant if you have multistandard TV.


 
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Message édité par nioc_bertheloneum le 27-07-2005 à 13:25:04
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