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  #16  
Old 07-31-2014, 07:32 AM
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Quote:
Originally Posted by NewVista View Post
First PAL sets used visual averaging of complementary hue errors (if any) over odd & even line pairs with different line in between creating annoying "venetian blind" artifact. Disastrous idea given interlaced scanning.
Because of the location where PAL was invented, this got the nickname "Hannover bars."
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  #17  
Old 08-01-2014, 01:05 AM
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AFAIK all UK colour TVs used delays lines and so didn't show Hanover blinds (or bars) unless the decoder was misaligned. The early Sony sets effectively converted PAL to NTSC and so didn't show them either.

The Telefunken PAL patents were administered by EMI in the UK. All the receiver manufacturers paid but EMI didn't both to chase the broadcast equipment manufacturers who made PAL encoders. I think this was a sort of de minimis thing as the numbers of encoders was tiny compared to decoders. Until some time in the early 1980s when EMI were going through one of their many financial panics. I was working at Michael Cox Electronics at the time and EMI threatened the company with royalty payments for all the 1000+ coders that MCE had manufactured since the late 1960s. I don't know how that was resolved.
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  #18  
Old 08-01-2014, 09:19 AM
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If PAL-Delay were working with progressive scan then V chroma res would be halved, but with interlace it becomes way more disastrous: The summed interlace pairs have double the separation. This, and its diminished "Kell factor" would take V chroma res down to <80 'lines'. Same for H chroma res with motion - maybe down to ~50 lines.

NTSC-M could achieve ~ 100 x 350 'lines' chroma
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  #19  
Old 08-02-2014, 01:10 AM
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Since chroma bandwidth is much lower than luma the reduction in vertical resolution doesn't matter. PAL decoding just about equalises the H and V chroma resolutions.

PAL decoding also moves the chroma down by half a line wrt luma. Again this doesn't matter unless you cascade codecs. More modern comb filter decoders can keep the Y and C in vertical alignment.
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  #20  
Old 08-02-2014, 09:53 AM
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"..moves the chroma down by half a line wrt luma."

The way I see it, it would be two lines displacement (line 1 to 3, line 2 to 4...)?
This would be another PAL-D chroma artifact - creating headaches for designers of decoders for standards converters..
The H res one being worse than progressive scan conversion sans motion compensation which blurs so badly
designers would rather just double fields (in early days) kind of like THAT notorious Sony "PAL" TV did).

Only the Germans could come up with such a Heath Robinson solution to Hanover Bars.

Last edited by NewVista; 08-02-2014 at 10:17 AM.
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  #21  
Old 08-03-2014, 05:33 PM
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PAL and SECAM were variations on a theme developed by NTSC. The acronyms I have heard for each are interesting and define well the politics between the variations:

NTSC - Never Twice the Same Colour (as explained earlier in this threa)

PAL - Problems Are Lurking - This name probably arose from the editing of PAL. It was painful because of the 8 field colour sequence rather than the four NTSC offered.

SECAM - System Essentially Contrary to the American Method - With France and it possessions and the Soviet Bloc adoption, the name says it all.
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  #22  
Old 08-04-2014, 06:58 AM
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Canada could have easily fallen prey to the German propagandists and ended up paying license fees for PAL-M like those suckers in Brazil.
Fortunately Canadian bureaucrats were on the ball.
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  #23  
Old 08-04-2014, 02:41 PM
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Originally Posted by NewVista View Post
Fortunately Canadian bureaucrats were on the ball.
Not something that can normally be said abut them.

Our flag for example: Yuck! Before that was brought in, the country's "de jure" flag was the Royal Union flag.

Enough about that I guess.

Last edited by Jon A.; 08-04-2014 at 02:44 PM.
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  #24  
Old 08-05-2014, 08:37 AM
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Wise government in Ottawa seeks compatibility with US standards.
I always thought Ottawa was in French Quebec! Till I looked it up! This morning!
If it was, Canada would have been SECAM ( Séquentiel couleur à mémoire )!
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  #25  
Old 08-28-2014, 08:44 AM
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Quote:
Originally Posted by NewVista View Post
Wise government in Ottawa seeks compatibility with US standards.
I always thought Ottawa was in French Quebec! Till I looked it up! This morning!
If it was, Canada would have been SECAM ( Séquentiel couleur à mémoire )!
& probably 819 lines then convert to 625 lines, both with positive modulation & AM sound..
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  #26  
Old 08-29-2014, 01:38 PM
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Originally Posted by dieseljeep View Post
It's really amazing that they can build Multi-standard color sets.
Back in 1996 I worked for Samsung developing a multistandard decoder chip. KS0127 datasheet. If the burst changed frequency line to line, it was SECAM. If the burst frequency was steady, and line to line phase was 180 degrees flip. it had to be NTSC, if it was (something like +45 and -45 IIRC), it was PAL. And we'd switch in the appropriate processing. Our chip could handle a variant of NTSC running at 4.43MHz subcarrier, or PAL with a subcarrier at 3.58, though few if any countries broadcast those. We PLLed on the horizontal line frequency and used counters to identify the burst subcarrier frequencies.
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  #27  
Old 08-30-2014, 09:52 AM
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Originally Posted by wa2ise View Post
Back in 1996 I worked for Samsung developing a multistandard decoder chip. KS0127 datasheet. If the burst changed frequency line to line, it was SECAM. If the burst frequency was steady, and line to line phase was 180 degrees flip. it had to be NTSC, if it was (something like +45 and -45 IIRC), it was PAL. And we'd switch in the appropriate processing. Our chip could handle a variant of NTSC running at 4.43MHz subcarrier, or PAL with a subcarrier at 3.58, though few if any countries broadcast those. We PLLed on the horizontal line frequency and used counters to identify the burst subcarrier frequencies.
I looked the data sheet and it's really impressive!
It took a group of highly-gifted engineers to come up with that scheme.
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  #28  
Old 09-03-2014, 02:05 AM
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KS0127 datasheet.

Says it comb filtered PAL with two lines storage, didn't know that could be done, wonder if later PAL TVs that promised Comb filtering really did it?
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  #29  
Old 09-03-2014, 02:16 AM
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Originally Posted by dieseljeep View Post
I looked the data sheet and it's really impressive!
It took a group of highly-gifted engineers to come up with that scheme.
Large analog+digital jungle-chip:

Done in Silicon Valley? Even with workstation circuit development > simulation > photo layout systems, what if fabricated batch had bugs!?

After all that development, many chips soon obsolete, before R&D costs can be recovered?
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  #30  
Old 09-03-2014, 06:25 AM
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in the real world...

Having seen PAL and NTSC in their real world forms OTA and on analogue cable...let's not over state the problems of either.

Far greater difference in quality with the two systems lies in the 525/60 625/50 standards.

From a viewer perspective .. 625 line (ie 576i) makes for a noticeably sharper image.

But I have to say my experience is that the colour via PAL is better (somehow red never looked right in NTSC) .... but the much feared phase error never occurred when viewing late NTSC OTA (80s+).. not sure if it was an issue in 50s and 60s.

Feeding my late model Sony Trinitron NTSC from tape or DVD vs same program from PAL sources subtle differences in colour and black level are noticeable... along with 24 to 30 frame motion issues on the NTSC versions.

I am not talking technically here but purely subjectively.. how it looks to me...clearly different TV sets and broadcasting quality would play a big part.

PAL sets do not have a phase control - Hue/Tint for a reason ... you simply do not see phase error even when present.

BUT none of this is fair.. what would 625 line NTSC look like or 525 line PAL? (Or for that matter SECAM)

What does 405 line NTSC /PAL look like? Anyone ever seen that? The BBC seems to have not wanted to migrate to 405 line colour using NTSC because it was too good and might have reduced the demand for the 625 line service.

Did you guys in the NTSC world with tube sets suffer phase errors when you still had analog broadcasts? Real world test ... not lab stuff.
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