composite and component waveform reference
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This forum is run by the BATC (British Amateur Television Club), it is service made freely available to all interested parties, please do not abuse this privilege.
Thank you
composite and component waveform reference
Greetings,
Does anyone have a suggestion as to a good description
of the composite and component waveforms for SD and
HD formats?
I have found some notes on the Internet but they all seem
to be missing bits or are in gawdy colours that are difficult
to read. I appear to have lost my BBC B course notes which
I think had a good description of the PAL waveform.
I am trying to implement a SD / HD test card generator on
an Altera FPGA development board. So I need quite detailed
information.
- Charles G4GUO
Does anyone have a suggestion as to a good description
of the composite and component waveforms for SD and
HD formats?
I have found some notes on the Internet but they all seem
to be missing bits or are in gawdy colours that are difficult
to read. I appear to have lost my BBC B course notes which
I think had a good description of the PAL waveform.
I am trying to implement a SD / HD test card generator on
an Altera FPGA development board. So I need quite detailed
information.
- Charles G4GUO
Re: composite and component waveform reference
Doppler effect: The tendency of stupid ideas to seem smarter when they come at you rapidly.
Re: composite and component waveform reference
Thanks, good try but it does not go into nearly enough detail.
The best I can find is.
http://www.pembers.freeserve.co.uk/Worl ... dards.html
It is suprising how little use much of the material on the internet is. I am sure
what I am looking for is out there somewhere.
It is the frame syncs I am having a problem with currently. My code generates
them but it is very complicated using state machines and I am sure there is a
simpler way to construct them.
- Charles
The best I can find is.
http://www.pembers.freeserve.co.uk/Worl ... dards.html
It is suprising how little use much of the material on the internet is. I am sure
what I am looking for is out there somewhere.
It is the frame syncs I am having a problem with currently. My code generates
them but it is very complicated using state machines and I am sure there is a
simpler way to construct them.
- Charles
Re: composite and component waveform reference
It seems if I need ITU-R recommendation BT.1700 unfortunately the
3 free downloads from the ITU bookshop is broken at the moment.
Oh well.
- Charles G4GUO
Seems as if the ITU bookshop does not like Firefox.
I changed to IE and have been able to download BT.1700
I now have 2 downloads left.
3 free downloads from the ITU bookshop is broken at the moment.
Oh well.
- Charles G4GUO
Seems as if the ITU bookshop does not like Firefox.
I changed to IE and have been able to download BT.1700
I now have 2 downloads left.
Re: composite and component waveform reference
Hi Charles,
This is the 625 system B frame sync structure:
http://www.pembers.freeserve.co.uk/Worl ... 25-PAL.pdf
All the other analogue systems are there too.
This is the 625 system B frame sync structure:
http://www.pembers.freeserve.co.uk/Worl ... 25-PAL.pdf
All the other analogue systems are there too.
Doppler effect: The tendency of stupid ideas to seem smarter when they come at you rapidly.
Re: composite and component waveform reference
Hi,
In the end I downloaded a copy of BT.1700 and have the
sync FPGA code done, I am just trying to figure out the
colour burst phase and blanking at the moment.
The field numbering is a bit confusing as they have
Field 1, Field 2 in one figure then field I, II, III, IV
in another and in one of the sets of notes they talk about
field 1,2,3,4,5,6,7,8
I think they mean
field
1 I 1
2 II 2
1 III 3
2 IV 4
1 I 5
2 II 6
1 III 7
2 IV 8
Well I hope they do!
- Charles
In the end I downloaded a copy of BT.1700 and have the
sync FPGA code done, I am just trying to figure out the
colour burst phase and blanking at the moment.
The field numbering is a bit confusing as they have
Field 1, Field 2 in one figure then field I, II, III, IV
in another and in one of the sets of notes they talk about
field 1,2,3,4,5,6,7,8
I think they mean
field
1 I 1
2 II 2
1 III 3
2 IV 4
1 I 5
2 II 6
1 III 7
2 IV 8
Well I hope they do!
- Charles
Re: composite and component waveform reference
If I remember correctly from when I used to teach this stuff at Wood Norton nearly 40 years ago, field 1 of the 8-field sequence is where the sub-carrier zero crossing is positive going at the leading edge of line 1 sync.
I may be wrong!
I may be wrong!
Doppler effect: The tendency of stupid ideas to seem smarter when they come at you rapidly.
Re: composite and component waveform reference
Well I finally managed to get enough information to get the FPGA code to work.
Just need to design a fancy looking test card next. There is only about 120 kbits
of memory in the small FPGA so it will have to be something simple. Still it has
proved a good learning exercise and makes me feel confident in tackling a more
complex project next.
I guess most people use a P.C these days for their testcards/video effects.
- Charles
Just need to design a fancy looking test card next. There is only about 120 kbits
of memory in the small FPGA so it will have to be something simple. Still it has
proved a good learning exercise and makes me feel confident in tackling a more
complex project next.
I guess most people use a P.C these days for their testcards/video effects.
- Charles