About video converters - a little need here...

[Alex KL-1]

I'm trying to find a HDMI to 480i component video converter/scaler, but this is not sooooo easy... almost all are HDMI to 480p or higher, and most even don't have scalers.
I have a notebook with S-Video with almost any interlaced format used in early 2000's in the world, but I want another device for not depending 100% of it, and another for a relative that have a old color TV and wants to use things like Chromecast on it (for fun).
Old color TV here is terrible to use this, because of the oddball PAL-M ("480i 60Hz PAL"). None of converters today have this format. All are NTSC or PAL that Europe used. With component or RGB, I can convert 480i RGB or de-matrixed component video to PAL-M using a IC, easily (I have one).
And thanks to PAL-M, I only have the mentioned notebook to watch old 4:3 programs in my old color TV's...

If people here have experience with those video scalers, I will very grateful with any tips!

[user181]

I use an HDMI-component video converter, and connect that to a Hall Research VHD-180 which performs scaling functions. The VHD-180 has component and VGA inputs, and component and composite outputs.

[jhalphen]

Hi to all,
Hi Alex KL-1,

Your question is interesting !
As a person used to coping with another weird color TV system (SECAM), i sympathise with you being constrained by the Brazilian PAL-M.

HDMI to component converter, (Y/Pr/Pb or RGB)
Don't know where you buy from, but saw these on Amazon USA:

https://www.amazon.com/Component-Con...jaz10cnVl&th=1

or this one:
https://www.amazon.com/EASYCEL-Compo...%2C218&sr=8-15

Apparently, none of these resize 16:9 to 4:3, so a scaler will also be required.
The Hall VHD-180 quoted by User181 (Thanks!) :

https://halltechav.com/product/vhd-180/

Component to PAL-M:
i understand you will build an encoder yourself.
BTW, what encoder IC are you planning on using; a Philips TDAxxx?

A second hand Broadcast encoder (RGB/YUV) would probably have PAL-M & N encoding, but is bulky (19" rack size, 1 or 2 Units height) + difficult to repair if it stops working. Look at brands like Snell & Wilcox (UK).

Best Regards
jhalphen
Paris/France

[Alex KL-1]

Thanks all for the tips!
The PAL-M encoder that I will have is: https://pdf1.alldatasheet.com/datash.../CXA1645M.html
It was from a Playstation 2 "NTSC to PAL-M converter", but in reality is a RGB to PAL-M converter.
In fact, in theory I can convert the C signal from S-Video from NTSC for PAL-M (I have a VGA to S-Video NTSC adapter), but I fear that double color conversion will distort the color too much. Better to use this convertors and scalers I think.
Interesting the VHD-180; for me, solves my problem, since I have another notebook and a PC with VGA. For my relative, I will need the HDMI converter anyway. But I need to discover how much she wants to spend on that...

Another question: Quality wise, I suppose this VHD-180 being better than el-cheapo VGA to NTSC S-Video converter? The one that I have (these cheap) distorts the red too much (over saturates it); the native NTSC (or PAL-M) DVD and DTV have more realistic colors than it. I use this NTSC converter with my newer multinorm TV's that have NTSC.
Same from notebook; even with careful adjustment, the image is not so good like same film/picture (for example) running on a DVD that have native old analog format. This will be my hope also with something like the VHD-180.

Ah, the SECAM color system... Since here is too far from countries using this, and I not travelled to countries using SECAM in the analog era, I never watched in person a TV using this system.

[jhalphen]

Hi to All,
Hi Alex KL-1,

Took me time to mull over what you are trying to achieve & understand better.

The Sony CXA1645M datasheet is interesting (Thanks!).
Apparently it encodes RGB to either standard 3.58 NTSC or 4.43 PAL.
to operate in Brazil Wikipedia describes the PAL-M subcarrier as :

"Exact colour subcarrier frequency of PAL-M is 3.575611 MHz"
from WK:
https://en.wikipedia.org/wiki/PAL#PAL-M_(Brazil)

You wrote:
"In fact, in theory I can convert the C signal from S-Video from NTSC for PAL-M"

I don't agree, the NTSC color component does not have the essential PAL alternation (swinging burst) & alternate line reversed R-Y component which is the heart of PAL.
To convert, you must decode NTSC to RGB or Y/B-Y/R-Y then re-encode in PAL system.
Only the subcarrier frequency is different between 4.43 Euro PAL & Brazil PAL-M.

We need to know more about what you want to achieve, this is what i understand:
Source #1 a computer with S-Video Composite out.

Source #2 would be what?
- Off air brazilian TV (digital). Set top box outputs what standard; NTSC or PAL?
- DVD ? standard PAL or NTSC out (i guess)

Source #3, streaming from NetFlix or other local streaming services?

Decoding to RGB 525/60 then re-encoding to PAL-M seems logical.

This appears to be a solution for your other sources:
"Interesting the VHD-180; for me, solves my problem, since I have another notebook and a PC with VGA"

About your relative with old (color?) TV: Brand/model/age
what signals can the TV receive:
- Off air PAL-M (VHF/UHF) only
- single standard PAL-M only or compatible with NTSC USA or PAL 625
- does it have an A/V input of Euro-type SCART connector?

It could work with the Sony RGB to PAL-M encoder + a RF Modulator to TV's antenna input. There are relatively cheap models which do all world standards such as the Terra MT-47, see enclosed data sheet. Full pdf manual downloadable here:

https://www.terraelectronics.com/pro...dulators/mt47/

Best Regards
jhalphen
Paris/France

[old_tv_nut]

Some mostly irrelevant math which you may nevertheless find interesting:

The exact NTSC subcarrier frequency is 455/2 x 15750 x 1000/1001.
The factor of 1/2 means there is an odd number + 1/2 cycles (227.5) per scan line time.
If you factor these numbers and calculate the exact frequency in lowest terms, it is
3579545 + 5/11 Hz.
The largest prime factor in this chain is 13, which is small enough to make stable tube frequency dividers.

In PAL-M, the subcarrier is offset by 1/4 cycle per horizontal scan time instead of 1/2 cycle, using
909/4 x 15750 x 1000/1001.
The exact frequency works out to 3575611 + 127/143 Hz.
The large prime factor of 101 in this chain only became practical with the advent of solid state digital counters.

These exact frequencies are obtained in equipment that is synchronized to atomic clock or GPS time, although the analog broadcast standards have a subcarrier tolerance of +/- 10 Hz to accommodate equipment based on oven-stabilized crystal oscillators.

Home equipment based on un-heated crystals will have a wider tolerance of subcarrier frequency, and in the case of some gear such as home VCRs, may not have the scan rate locked to the subcarrier.

[Alex KL-1]

Originally Posted by jhalphen

Hi to All,
Hi Alex KL-1,

Took me time to mull over what you are trying to achieve & understand better.

The Sony CXA1645M datasheet is interesting (Thanks!).
Apparently it encodes RGB to either standard 3.58 NTSC or 4.43 PAL.
to operate in Brazil Wikipedia describes the PAL-M subcarrier as :

"Exact colour subcarrier frequency of PAL-M is 3.575611 MHz"
from WK:
https://en.wikipedia.org/wiki/PAL#PAL-M_(Brazil)

You wrote:
"In fact, in theory I can convert the C signal from S-Video from NTSC for PAL-M"

I don't agree, the NTSC color component does not have the essential PAL alternation (swinging burst) & alternate line reversed R-Y component which is the heart of PAL.
To convert, you must decode NTSC to RGB or Y/B-Y/R-Y then re-encode in PAL system.
Only the subcarrier frequency is different between 4.43 Euro PAL & Brazil PAL-M.

We need to know more about what you want to achieve, this is what i understand:
Source #1 a computer with S-Video Composite out.

Source #2 would be what?
- Off air brazilian TV (digital). Set top box outputs what standard; NTSC or PAL?
- DVD ? standard PAL or NTSC out (i guess)

Source #3, streaming from NetFlix or other local streaming services?

Decoding to RGB 525/60 then re-encoding to PAL-M seems logical.

This appears to be a solution for your other sources:
"Interesting the VHD-180; for me, solves my problem, since I have another notebook and a PC with VGA"

About your relative with old (color?) TV: Brand/model/age
what signals can the TV receive:
- Off air PAL-M (VHF/UHF) only
- single standard PAL-M only or compatible with NTSC USA or PAL 625
- does it have an A/V input of Euro-type SCART connector?

It could work with the Sony RGB to PAL-M encoder + a RF Modulator to TV's antenna input. There are relatively cheap models which do all world standards such as the Terra MT-47, see enclosed data sheet. Full pdf manual downloadable here:

https://www.terraelectronics.com/pro...dulators/mt47/

Best Regards
jhalphen
Paris/France

Sorry... Long time has passed; I don't know but I simply not noted if the notification about message not read not appeared or simply I don't see (much more probable), but... never later than never...

In fact, I have 2 objectives here:
1 - to find a spare device for my laptop, preferably with image quality like a Playstation 2 (to me the best S-Video quality I've used om my TV's), so quality is a must here;
2 - to find an alternative to my relative (el-cheap alternative); more on that below.

"In fact, in theory I can convert the C signal from S-Video from NTSC for PAL-M"

I don't agree, the NTSC color component does not have the essential PAL alternation (swinging burst) & alternate line reversed R-Y component which is the heart of PAL.
To convert, you must decode NTSC to RGB or Y/B-Y/R-Y then re-encode in PAL system.
Yes, that is the idea, your description was far better than mine

About the devices:
"We need to know more about what you want to achieve, this is what i understand:

Source #1 a computer with S-Video Composite out."
This is my personal solution, the laptop with S-Video mentioned.
My relative don't have this option.

"Source #2 would be what?
- Off air brazilian TV (digital). Set top box outputs what standard; NTSC or PAL?
- DVD ? standard PAL or NTSC out (i guess)"
These sources are ok for me; I have a DVD player and a ISDB-TV decoder, since all of it already have native PAL-M. My relative don't have interest in these sources.

"Source #3, streaming from NetFlix or other local streaming services?"
In my case, is same as Source 1. But, my relative wants to use some modern streaming "receiver" device like ChromeCast, or even her laptop, having only HDMI out.

"Decoding to RGB 525/60 then re-encoding to PAL-M seems logical.

This appears to be a solution for your other sources:
"Interesting the VHD-180; for me, solves my problem, since I have another notebook and a PC with VGA

About your relative with old (color?) TV: Brand/model/age
what signals can the TV receive:
- Off air PAL-M (VHF/UHF) only
- single standard PAL-M only or compatible with NTSC USA or PAL 625
- does it have an A/V input of Euro-type SCART connector?"
This is a brazilian Toshiba using Philips TDA3561 video processor. originally it only has off air input as usual, but I already made a S-Video input switch, and I can even can make a RGB input (like SCART) if needed (inputs with proper isolation trafo, since is a live chassis...). This will produces a lot of options, and this will simplifies in theory, but is difficult to find a "el-cheapo" converter having 480i RGB output, or even S-Video; is outside of her budget. I found various cheap 480p converters, completely useless for this case.
I even studied the Philips cousin NTSC processor, to change in place of PAL decoder, but pinout is radically different. Too much hard work...


"It could work with the Sony RGB to PAL-M encoder + a RF Modulator to TV's antenna input. There are relatively cheap models which do all world standards such as the Terra MT-47, see enclosed data sheet. Full pdf manual downloadable here:

https://www.terraelectronics.com/pro...dulators/mt47/"
Interesting versatile modulator! Thanks for the tip; wil be very useful if someone request me a RF quality solution.

Best Regards,
Alexandre

[Alex KL-1]

Originally Posted by old_tv_nut

Some mostly irrelevant math which you may nevertheless find interesting:

The exact NTSC subcarrier frequency is 455/2 x 15750 x 1000/1001.
The factor of 1/2 means there is an odd number + 1/2 cycles (227.5) per scan line time.
If you factor these numbers and calculate the exact frequency in lowest terms, it is
3579545 + 5/11 Hz.
The largest prime factor in this chain is 13, which is small enough to make stable tube frequency dividers.

In PAL-M, the subcarrier is offset by 1/4 cycle per horizontal scan time instead of 1/2 cycle, using
909/4 x 15750 x 1000/1001.
The exact frequency works out to 3575611 + 127/143 Hz.
The large prime factor of 101 in this chain only became practical with the advent of solid state digital counters.

These exact frequencies are obtained in equipment that is synchronized to atomic clock or GPS time, although the analog broadcast standards have a subcarrier tolerance of +/- 10 Hz to accommodate equipment based on oven-stabilized crystal oscillators.

Home equipment based on un-heated crystals will have a wider tolerance of subcarrier frequency, and in the case of some gear such as home VCRs, may not have the scan rate locked to the subcarrier.

Very interesting! In fact, the color TV commercially speaking here was implemented in 1970 (about the difficult counters).

[jhalphen]

Hi to all,
Hi Alex KL-1,

While browsing on the topic of PAL-M, found this Tecnovideo 3240 NTSC to PAL-M transcoder, most probably geared towards the Brazilian market. Manufacturer is an Italian company specialized in CCTV gear.
Any use for you?

Photos & an advert for the product enclosed.
Seller :

http://www.reidosom.com.br/produtos.html

Also the data sheet for the Analog Devices AD722, a very simple (no coils) RGB to PAL or NTSC encoder IC.

Best Regards
jhalphen
Paris/France

[Alex KL-1]

This converter is a good solution for my relative, for using the el-cheapo HDMI to NTSC converter, but... Too bad this is outside to her budget...

Very interesting the AD722.