PI2SCART settings for 480p / 480i

[b.busch]

Hello. How should I configure my PI2SCART adapter to get 480p or 480i video with minimal overscan?
I'm getting brilliant 240p video on my Sony PVM monitor (with a SCART to RGBS BNC adapter) using the following settings in my config.txt:

Code: Select all

disable_audio_dither=1
dtparam=audio=on
dtoverlay=vga666
enable_dpi_lcd=1
display_default_lcd=1
dpi_group=2
dpi_mode=87
hdmi_timings=320 1 16 30 34 240 1 2 3 22 0 0 0 60 0 6400000 1 #240p

[drgeoff]

Possibly you cannot.

480p requires a horizontal rate of about 31kHz. That is twice the rate for 480i or 240p. Can your display handle that?

[jordanius]

I have been trying to use Kodi on a first generation plasma with pi2scart and would love to know the answer to this also (specifically a 480i/576i hdmi_setting). I enquired on the pi2jamma FB group which generated a bit of interest but noone could work it out. Maybe the pi2scart developers could help.

[b.busch]

Possibly you cannot.

480p requires a horizontal rate of about 31kHz. That is twice the rate for 480i or 240p. Can your display handle that?

It's worth a try! What about 480i? I'm not a hardware programming expert, so the hdmi_timings parameters are unfortunately a mystery to me. Do you have a suggestion to code that line for 480p or 480i with similar variables to those in the quoted line above?

[fruitoftheloom]

Possibly you cannot.

480p requires a horizontal rate of about 31kHz. That is twice the rate for 480i or 240p. Can your display handle that?

It's worth a try! What about 480i? I'm not a hardware programming expert, so the hdmi_timings parameters are unfortunately a mystery to me. Do you have a suggestion to code that line for 480p or 480i with similar variables to those in the quoted line above?

The Pi2Scart uses the "dtoverlay=vga666" which is the same as Gertbaord VGA666, therefore can you not try those DPi settings ??

viewtopic.php?f=28&t=187586

https://www.raspberrypi.org/documentati ... /README.md

[b.busch]

The Pi2Scart uses the "dtoverlay=vga666" which is the same as Gertbaord VGA666, therefore can you not try those DPi settings ??

viewtopic.php?f=28&t=187586

https://www.raspberrypi.org/documentati ... /README.md

Thanks for your suggestion. Unfortunately, the Gertboard VGA666 settings are not compatible with the PI2SCART (I just tested them).

[b.busch]

Possibly you cannot.

480p requires a horizontal rate of about 31kHz. That is twice the rate for 480i or 240p. Can your display handle that?

To answer more specifically: My display (Sony PVM) can only handle 15kHz. The tough part is figuring out what hdmi_timings to use (because none of the standard settings for 480i work with the PI2SCART).

[drgeoff]

I don't have a Pi2SCART or a GertVGA.

My understanding is that the 0 following the 60 means 'not interlaced'. Try changing that to 1.

[b.busch]

I stumbled upon this helpful video timing calculator: http://www.epanorama.net/faq/vga2rgb/calc.html
Using the variables generated for "640x480 NTSC TV interlaced", I inferred the following hdmi_timings lines with alternating sync polarity (the settings suggested for the Pi2SCART have h_sync_polarity=1 and v_sync_polarity=1):

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hdmi_timings=640 1 16 88 64 240 1 6 5 13 0 0 0 60 1 12700000 1 #480i sync_polarity=1
hdmi_timings=640 0 16 88 64 240 0 6 5 13 0 0 0 60 1 12700000 1 #480i sync_polarity=0

I'm away from my Pi2SCART setup until Monday. Maybe somebody wants to test in the meantime?

[b.busch]

I stumbled upon this helpful video timing calculator: http://www.epanorama.net/faq/vga2rgb/calc.html
Using the variables generated for "640x480 NTSC TV interlaced", I inferred the following hdmi_timings lines with alternating sync polarity (the settings suggested for the Pi2SCART have h_sync_polarity=1 and v_sync_polarity=1):

Code: Select all

hdmi_timings=640 1 16 88 64 240 1 6 5 13 0 0 0 60 1 12700000 1 #480i sync_polarity=1
hdmi_timings=640 0 16 88 64 240 0 6 5 13 0 0 0 60 1 12700000 1 #480i sync_polarity=0

I'm away from my Pi2SCART setup until Monday. Maybe somebody wants to test in the meantime?

Try also the following line, using the same pixel clock frequency (and sync polarity) as the suggested settings for Pi2SCART:

Code: Select all

hdmi_timings=640 1 16 88 64 240 1 6 5 13 0 0 0 60 1 6400000 1 #480i

[b.busch]

Try also the following line, using the same pixel clock frequency (and sync polarity) as the suggested settings for Pi2SCART:

Code: Select all

hdmi_timings=640 1 16 88 64 240 1 6 5 13 0 0 0 60 1 6400000 1 #480i

These settings make something happen on the screen, but the sync is obviously not working and the picture is not coming in correctly. Anybody?

[bleck]

Maybe this is relevant

https://github.com/raspberrypi/linux/co ... 2e901fb1bd

Code: Select all

drm/vc4: Disallow interlaced modes on DPI.
We already don't expose such modes to userspace, but make
sure userspace can't sneak some interlaced mode in.

Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>