STICKY: HOWTO: Create Custom HDMI modes

[trio198]

Hi again,

Can someone en-light me please? Been stuck with the display configuration.

Thanks.

[quarterturn]

I've been playing around with retropie and an "old" Sony 4:3 480i TV. The TV has component inputs, so I bought an HDMI-component converter. This works fine under X on a laptop using the following:
xrandr --newmode "640x480i-2" 12.324 640 648 706 784 480 483 489 524 interlace -hsync -vsync

On the pi, with 'hdmi_mode=6', there is flagging at the top of the picture along with a grey rectangle. I am guessing this is some sort of vertical sync issue. Here are some photos: http://imgur.com/a/0Bk5X

I've tried translating the X modeline to the custom hdmi mode format, but no luck. Does anyone have a custom mode for 480i that works?

If we can get this working, this is the cheapest way to get close to the arcade monitor experience for MAME. Analog TVs with component inputs can be had for next to nothing, vs. $600-$700 for an arcade monitor of similar size. The HDMI-component box is about $20. The only drawback I see is component seems a little blurry on reds, but this could be due to my cheap $20 HDMI converter or even the TV.

[Stahl80]

Hope this is in the correct forum index. I'm running retropie on a Pi2 with a waveshare 7inch LCD. I installed drivers for the LCD that supports the touch and sets the correct resolution (800x480). (Driver: https://github.com/derekhe/waveshare-7i ... een-driver). Works perfect as long as I connect the Pi to the LCD, if I disconnect the LCD and connect the HDMI to a tv I get "unsupported signal". My guess is that the driver sets the output resolution to 800x480 and that's not supported by the tv. Is there a way to add a second resolution set so the Pi switches to say 730p when I connect it to my tv?
Relay appreciate any help!
Thanks

[krt]

Hi,

Is there any documentation on converting an xorg ModeLine to "hdmi_timings" format ?

Modeline syntax: pclk hdisp hsyncstart hsyncend htotal vdisp vsyncstart vsyncend vtotal [flags] Flags (optional): +HSync, -HSync, +VSync, -VSync, Interlace, DoubleScan, CSync, +CSync, -CSync

e.g.: ModeLine "1366x768" 84.75 1366 1440 1584 1776 768 769 772 800 -hsync +vsync

I have a TV with the above resolution that works fine under xorg (with this modeline), but none of the RPi hdmi settings worked at all. It looks like the same information to me, just the format is different.

ta,
-krt

[quarterturn]

As a follow-up to my above post, I set the HDMI-component converter back up with my laptop and TV. I don't think the adapter can actually output an interlaced signal. With the following modeline "sudo xrandr --newmode "720x480@30i" 13.5 720 736 799 858 480 486 492 525 interlace -hsync -vsync" there is a nice, stable picture, but it's definitely not interlaced.

I could live with this for mame, where most games are fine with something like 200 or 240 lines, but I still have no idea how to set the custom mode. I guess if I really want this working right I'll have to try a different HDMI adapter.

[quarterturn]

One last post on the HDMI-component situation. Selecting a 240p mode from the hdmi_modes table does indeed get the adapter to output a 240p signal. My Sony PVM-1344Q monitor is OK with this signal, but there remains a black rectangle at the top of the picture. My guess is that in 240p mode, the adapter gets the vertical sync wrong. Too bad, as it otherwise looks very good.

[matias]

I suppose writing about this issue in this thread makes more sense than adding a new one: I'm trying to make AJA HA5 HDMI to SDI converter work with RPi 2 (or any Raspberry in fact). I'm aming for the standard 1080i50 PAL mode. The issue is that it works only when:

a) pixel encoding is set to RGB (limited, full also possible with correct jumper setting on the converter)
b) omxplayer plays something first (regardless of -z or -y hdmi clock sync options used)

And even then I's not stable. Some dropouts appear, it looks as if the converter looses synchronisation. And the stability is way better in 30 and 29.97 modes.
I can't make the console visible in the first place (i.e. at boot time) but the signal is clearly there, because I see this behaviour only with AJA converters. Blackmagic Designs and OEM/noname el-cheapo Chinese work fine. Only after the first clip has been played, the console stays visible on AJA's output.

As for my investigation: a) is most likely due to YCbCr444 on RPi HDMI output. EDID shows that the converter expects RGB or YCbCr422. I'm not aware of any way to set the output pixel encoding to YCbCr422. And as b) goes I have no idea why it works only after omxplayer played something. I think it must be something with the timings, but I have no idea what exactly, nor the access to equipment that would allow me to measure the signals. Below is the EDID from AJA HA5:

Code: Select all

HDMI:EDID version 1.3, 1 extensions, screen size 70x39 cm
HDMI:EDID features - videodef 0x80 !standby !suspend !active off; colour encoding:RGB444|YCbCr422; sRGB is not default colourspace; preferred format is native; does not support GTF
HDMI:EDID found monitor range descriptor tag 0xfd
HDMI:EDID monitor range offsets: V min=0, V max=0, H min=0, H max=0
HDMI:EDID monitor range: vertical is 24-60 Hz, horizontal is 15-68 kHz, max pixel clock is 80 MHz
HDMI:EDID monitor range does not support GTF
HDMI:EDID found monitor S/N descriptor tag 0xff
HDMI:EDID found monitor name descriptor tag 0xfc
HDMI:EDID monitor name is HA5
HDMI:EDID found preferred CEA detail timing format: 1920x1080i @ 60 Hz (5)
HDMI:EDID established timing I/II bytes are 00 00 00
HDMI:EDID standard timings block x 8: 0x0101 0101 0101 0101 0101 0101 0101 01C1 
HDMI:EDID unknown standard timing 256x144 @ 61 Hz aspect ratio (16:9)
HDMI:EDID parsing v3 CEA extension 0
HDMI:EDID monitor support - underscan IT formats:no, basic audio:yes, yuv444:no, yuv422:yes, #native DTD:1
HDMI:EDID found CEA detail timing format: 1920x1080i @ 50 Hz (20)
HDMI:EDID found CEA format: code 5, 1920x1080i @ 60Hz (native)
HDMI:EDID found CEA format: code 20, 1920x1080i @ 50Hz (native)
HDMI:EDID found CEA format: code 4, 1280x720p @ 60Hz (native)
HDMI:EDID found CEA format: code 19, 1280x720p @ 50Hz (native)
HDMI:EDID found CEA format: code 6, 1440x480i @ 60Hz (native)
HDMI:EDID found CEA format: code 7, 1440x480i @ 60Hz (native)
HDMI:EDID found CEA format: code 21, 1440x576i @ 50Hz (native)
HDMI:EDID found CEA format: code 22, 1440x576i @ 50Hz (native)
HDMI:EDID found CEA format: code 34, 1920x1080p @ 30Hz (native)
HDMI:EDID found CEA format: code 33, 1920x1080p @ 25Hz (native)
HDMI:EDID found CEA format: code 32, 1920x1080p @ 24Hz (native)
HDMI:EDID found CEA format: code 1, 640x480p @ 60Hz 
HDMI:EDID found audio format 8 channels PCM, sample rate: 32|44|48|88|96|176|192 kHz, sample size: 16|20|24 bits
HDMI:EDID found HDMI VSDB length 6
HDMI:EDID HDMI VSDB has physical address 1.0.0.0
HDMI:EDID HDMI VSDB supports AI:no, dual link DVI:no
HDMI:EDID HDMI VSDB deep colour support - 48-bit:no 36-bit:no 30-bit:no DC_yuv444:no
HDMI:EDID HDMI VSDB has no latency information
HDMI:EDID adding mandatory support for DMT (4) 640x480p @ 60Hz
HDMI:EDID adding mandatory support for CEA (2) 720x480p @ 60Hz
HDMI:EDID adding mandatory support for CEA (3) 720x480p @ 60Hz
HDMI:EDID adding mandatory support for CEA (17) 720x576p @ 50Hz
HDMI:EDID adding mandatory support for CEA (18) 720x576p @ 50Hz
HDMI:EDID filtering formats with pixel clock > 162 MHz or h. blanking > 1023
HDMI:EDID best score mode initialised to CEA (1) 640x480p @ 60 Hz with pixel clock 25 MHz (score 0)
HDMI:EDID best score mode is now CEA (1) 640x480p @ 60 Hz with pixel clock 25 MHz (score 61864)
HDMI:EDID best score mode is now CEA (2) 720x480p @ 60 Hz with pixel clock 27 MHz (score 66472)
HDMI:EDID CEA mode (3) 720x480p @ 60 Hz with pixel clock 27 MHz has a score of 66472
HDMI:EDID best score mode is now CEA (4) 1280x720p @ 60 Hz with pixel clock 74 MHz (score 190888)
HDMI:EDID DMT mode (4) 640x480p @ 60 Hz with pixel clock 25 MHz has a score of 18432
HDMI:EDID best score mode is now CEA (5) 1920x1080i @ 60 Hz with pixel clock 74 MHz (score 5398248)
HDMI:EDID CEA mode (6) 1440x480i @ 60 Hz with pixel clock 27 MHz has a score of 56104
HDMI:EDID CEA mode (7) 1440x480i @ 60 Hz with pixel clock 27 MHz has a score of 56104
HDMI:EDID CEA mode (17) 720x576p @ 50 Hz with pixel clock 27 MHz has a score of 66472
HDMI:EDID CEA mode (18) 720x576p @ 50 Hz with pixel clock 27 MHz has a score of 66472
HDMI:EDID CEA mode (19) 1280x720p @ 50 Hz with pixel clock 74 MHz has a score of 163240
HDMI:EDID CEA mode (20) 1920x1080i @ 50 Hz with pixel clock 74 MHz has a score of 4836040
HDMI:EDID CEA mode (21) 1440x576i @ 50 Hz with pixel clock 27 MHz has a score of 56104
HDMI:EDID CEA mode (22) 1440x576i @ 50 Hz with pixel clock 27 MHz has a score of 56104
HDMI:EDID CEA mode (32) 1920x1080p @ 24 Hz with pixel clock 74 MHz has a score of 174298
HDMI:EDID CEA mode (33) 1920x1080p @ 25 Hz with pixel clock 74 MHz has a score of 180520
HDMI:EDID CEA mode (34) 1920x1080p @ 30 Hz with pixel clock 74 MHz has a score of 211624
HDMI:EDID preferred mode remained as CEA (5) 1920x1080i @ 60 Hz with pixel clock 74 MHz
HDMI:EDID has HDMI support and audio support

[Grasshopper2]

Can someone tell me whether it's possible to create a custom HDMI mode 'on the fly' i.e. after the RPi has been booted?

Thanks in advance

[quarterturn]

Certainly, if you're willing to use xorg vs the framebuffer.

[Grasshopper2]

Certainly, if you're willing to use xorg vs the framebuffer.

I'm sorry, but I don't really understand what you're saying. Can you elaborate?

I'm aware that the framebuffer resolution can be changed after the RPi has been booted by, for example, using fbset. However, my understanding is that, if you change the resolution that way, then all that really happens is that the GPU scales the image for you. The actual signal being sent to the TV/monitor doesn't change.

Another issue with changing the framebuffer resolution using GPU scaling is that the driver always forces the pixels to be square, which is not necessarily what you want if you're emulating old hardware.

[davidcoton]

Another issue with changing the framebuffer resolution using GPU scaling is that the driver always forces the pixels to be square, which is not necessarily what you want if you're emulating old hardware.

The driver doesn't know or care what shape your pixels are. That is determined by the physical screen (at least for LCD or similar displays -- crts are different, here the analogue signal timing from the output hardware is relevant). You cannot display non-square pixels on a screen with square pixels, unless you change the resolution to use 2 or even 6 screen pixels for each image pixel -- but again, the driver wouldn't know that you were displaying non-square pixels -- just that you want to display a different screen resolution. The screen may or may not accept that resolution, and may or may not display it the way you expect.

[floris497]

Is this topic still open, i have a display with a 640:121 aspect ratio.. is there any way i can get this to work? I use an HDMI->VGA adapter to send the signal to the LCD. i have no idea where to go from here, tried few different things with xrandr and the config.txt but nothing works.. :/

thanks in advance

[Grasshopper2]

Is this topic still open

I certainly hope so, because as far as I'm concerned, it's still an unresolved issue.

Being able to set up a single custom mode at boot time is better than nothing. But I really need the ability to create custom modes on the fly.

[Grasshopper2]

Another issue with changing the framebuffer resolution using GPU scaling is that the driver always forces the pixels to be square, which is not necessarily what you want if you're emulating old hardware.

The driver doesn't know or care what shape your pixels are. That is determined by the physical screen (at least for LCD or similar displays -- crts are different, here the analogue signal timing from the output hardware is relevant). You cannot display non-square pixels on a screen with square pixels, unless you change the resolution to use 2 or even 6 screen pixels for each image pixel -- but again, the driver wouldn't know that you were displaying non-square pixels -- just that you want to display a different screen resolution. The screen may or may not accept that resolution, and may or may not display it the way you expect.

OK, strictly speaking, you're correct. What I should have said is the the driver always forces the aspect ratio of the pixels to remain constant regardless of what resolution is chosen. Or to put it another way, the driver always scales the image by the same factor in both the x and y planes.

I assumed that most people would set their default framebuffer resolution to show square pixels on the particular monitor that they're using. But I suppose that might not always be the case.

I started another thread on this subject which explains what I mean in more detail:

viewtopic.php?f=29&t=136899

Unfortunately, this is another unresolved issue. It's frustrating that, after four years, there are still some fundamental settings that you can't properly configure with the RPi drivers.

[floris497]

Is this topic still open

I certainly hope so, because as far as I'm concerned, it's still an unresolved issue.

Being able to set up a single custom mode at boot time is better than nothing. But I really need the ability to create custom modes on the fly.

But that does not work for me.. i can't get the resolution at all.. or am i missing something i cannot select my desired screen ratio.. or 640:121 or did i miss a post where was explained how this can be done?

If needed i can post EDID of the display.

[wmlooi]

latest "next" firmware has some changes to custom hdmi modes.

CVT now uses a single config string to set up. (First post edited)

You can also play with the raw hdmi timings:

The hdmi_timings parameters are:

Code: Select all

hdmi_timings=<h_active_pixels> <h_sync_polarity <h_front_porch> <h_sync_pulse> <h_back_porch> <v_active_lines> <v_sync_polarity> <v_front_porch> <v_sync_pulse> <v_back_porch> <v_sync_offset_a> <v_sync_offset_b> <pixel_rep> <frame_rate> <interlaced> <pixel_freq> <aspect_ratio>

You wil obviously need a timing data sheet for the display, and quite possibly a scope to debug what is happening, but it may allow non-standard displays to be driven.

The aspect ratio is:

Code: Select all

HDMI_ASPECT_4_3 = 1
HDMI_ASPECT_14_9 = 2
HDMI_ASPECT_16_9 = 3
HDMI_ASPECT_5_4 = 4
HDMI_ASPECT_16_10 = 5
HDMI_ASPECT_15_9 = 6
HDMI_ASPECT_21_9 = 7
HDMI_ASPECT_64_27 = 8

It will appear as the last hdmi_mode (87 for DMT, 65 for CEA). Use hdmi_group to determine CEA or DMT.

This was my test, for VGA@75

Code: Select all

hdmi_group=2
hdmi_mode=87
hdmi_timings=640 0 16 64 120 480 0 1 3 16 0 0 0 75 0 31500000 1

[edit: use hdmi_timings rather than hdmi_timing]

Hi,

Will this work for custom CEA mode?
hdmi_cvt=1280 960 60 1 0 0 0
hdmi_group=1
hdmi_mode=65
hdmi_drive=2

[dom]

Will this work for custom CEA mode?
hdmi_cvt=1280 960 60 1 0 0 0
hdmi_group=1
hdmi_mode=65
hdmi_drive=2

No, hdmi_cvt creates a custom DMT mode.
I'm not sure CVT timings make sense with CEA - can you say why you want this?

[wmlooi]

Hi dom,

When I used CEA mode, my monitor can shows a image. But for DMT mode, the monitor just blank during boot. I can see the Pi Zero are booting because the LED is blinking. That's why I want to create a custom CEA mode that suite my monitor to solve the "Input Signal Out of Range" problem.
Thanks.

[Edlwise]

Hello
I am trying to use HDMI port with other interface the to display videos in large LED display that use only 96x96 pixels , do you have any Idea about that
Regards

[sigmaris]

Is there any way to create more than one custom mode with hdmi_timings and then switch between them using "tvservice"? What I actually have is an 15/25kHz arcade monitor connected via the VGA666 adapter, using DPI (not HDMI, but hdmi_timings seems to be the way to set custom video modes for the DPI interface as well). I'm running MAME4ALL to play arcade games and trying to get the display to be as close as possible to the original hardware.

With a custom hdmi_timings line, I can boot in either a 320x240p 15kHz mode or a 512x384p 25kHz mode. But I'd like to switch between a few different modes for different games - as there are many different video modes used by the various games MAME supports. I'd like to be able to define custom modes 87, 88, 89, 90, etc and switch to the appropriate mode when launching a game using "tvservice". Failing that, is there any way to set custom timings after boot using tvservice or a similar tool?

[PetteriB]

Is there any way to create more than one custom mode with hdmi_timings and then switch between them using "tvservice"? What I actually have is an 15/25kHz arcade monitor connected via the VGA666 adapter, using DPI (not HDMI, but hdmi_timings seems to be the way to set custom video modes for the DPI interface as well). I'm running MAME4ALL to play arcade games and trying to get the display to be as close as possible to the original hardware.

With a custom hdmi_timings line, I can boot in either a 320x240p 15kHz mode or a 512x384p 25kHz mode. But I'd like to switch between a few different modes for different games - as there are many different video modes used by the various games MAME supports. I'd like to be able to define custom modes 87, 88, 89, 90, etc and switch to the appropriate mode when launching a game using "tvservice". Failing that, is there any way to set custom timings after boot using tvservice or a similar tool?

I too would like to know if there's a solution to this. I myself have a Raspberry Pi Zero powered emulation machine attached to an old CRT TV via VGA666 and VGA -> SCART adapter. To achieve the best possible image quality, I have created custom modes for each system I use (256x192 for Sega Master System, 256x240 for NES/SNES, 320x224 for Sega Genesis, 320x256 for Amiga).

However, since I couldn't find a way to define more than one custom mode or how to update hdmi_timings "on the fly", my only choice was to create a script that directly modifies the hdmi_timings in /boot/config.txt and then reboots the machine.

Needless to say, this is a really ugly and hackish way to do it and I would very much prefer to replace it with some faster and cleaner method if there's any.

[trio198]

Is there any way to create more than one custom mode with hdmi_timings and then switch between them using "tvservice"? What I actually have is an 15/25kHz arcade monitor connected via the VGA666 adapter, using DPI (not HDMI, but hdmi_timings seems to be the way to set custom video modes for the DPI interface as well). I'm running MAME4ALL to play arcade games and trying to get the display to be as close as possible to the original hardware.

With a custom hdmi_timings line, I can boot in either a 320x240p 15kHz mode or a 512x384p 25kHz mode. But I'd like to switch between a few different modes for different games - as there are many different video modes used by the various games MAME supports. I'd like to be able to define custom modes 87, 88, 89, 90, etc and switch to the appropriate mode when launching a game using "tvservice". Failing that, is there any way to set custom timings after boot using tvservice or a similar tool?

I too would like to know if there's a solution to this. I myself have a Raspberry Pi Zero powered emulation machine attached to an old CRT TV via VGA666 and VGA -> SCART adapter. To achieve the best possible image quality, I have created custom modes for each system I use (256x192 for Sega Master System, 256x240 for NES/SNES, 320x224 for Sega Genesis, 320x256 for Amiga).

However, since I couldn't find a way to define more than one custom mode or how to update hdmi_timings "on the fly", my only choice was to create a script that directly modifies the hdmi_timings in /boot/config.txt and then reboots the machine.

Needless to say, this is a really ugly and hackish way to do it and I would very much prefer to replace it with some faster and cleaner method if there's any.

Hi PetteriB,

Do you mind sharing your config.txt file?

Thanks mate...

[PetteriB]

Hi PetteriB,

Do you mind sharing your config.txt file?

Thanks mate...

Here you go:

Code: Select all

disable_overscan=1
dtparam=audio=on

gpu_mem_256=128
gpu_mem_512=256
gpu_mem_1024=256

# Enable VGA666
dtoverlay=vga666
enable_dpi_lcd=1
display_default_lcd=1
dtparam=spi=off
dtparam=i2c_arm=off

# Custom 15kHz mode
dpi_group=2
dpi_mode=87

hdmi_timings=320 1 20 29 35 224 1 10 14 16 0 0 0 60 0 6400000 1 # 320:224 Sega Genesis (NTSC)

And here's the complete list of timings I'm currently using:

Code: Select all

hdmi_timings=256 1 6 17 18 192 1 26 22 29 0 0 0 60 0 4800000 1 # 256:192 Sega Master System (NTSC)
hdmi_timings=256 1 8 17 21 224 1 7 10 24 0 0 0 60 0 4800000 1 # 256:224 NES, SNES (NTSC)
hdmi_timings=320 1 20 29 35 224 1 10 14 16 0 0 0 60 0 6400000 1 # 320:224 Sega Genesis (NTSC)
hdmi_timings=320 1 14 46 28 256 1 17 32 9 0 0 0 50 0 6400000 1 # 320:256 Amiga (PAL)

[trio198]

Here you go:

Code: Select all

disable_overscan=1
dtparam=audio=on

gpu_mem_256=128
gpu_mem_512=256
gpu_mem_1024=256

# Enable VGA666
dtoverlay=vga666
enable_dpi_lcd=1
display_default_lcd=1
dtparam=spi=off
dtparam=i2c_arm=off

# Custom 15kHz mode
dpi_group=2
dpi_mode=87

hdmi_timings=320 1 20 29 35 224 1 10 14 16 0 0 0 60 0 6400000 1 # 320:224 Sega Genesis (NTSC)

And here's the complete list of timings I'm currently using:

Code: Select all

hdmi_timings=256 1 6 17 18 192 1 26 22 29 0 0 0 60 0 4800000 1 # 256:192 Sega Master System (NTSC)
hdmi_timings=256 1 8 17 21 224 1 7 10 24 0 0 0 60 0 4800000 1 # 256:224 NES, SNES (NTSC)
hdmi_timings=320 1 20 29 35 224 1 10 14 16 0 0 0 60 0 6400000 1 # 320:224 Sega Genesis (NTSC)
hdmi_timings=320 1 14 46 28 256 1 17 32 9 0 0 0 50 0 6400000 1 # 320:256 Amiga (PAL)

Nice....thanks a lot brother....

[tekn0]

One last post on the HDMI-component situation. Selecting a 240p mode from the hdmi_modes table does indeed get the adapter to output a 240p signal. My Sony PVM-1344Q monitor is OK with this signal, but there remains a black rectangle at the top of the picture. My guess is that in 240p mode, the adapter gets the vertical sync wrong. Too bad, as it otherwise looks very good.

I am having an issue as well. I purchased this adapter. https://www.radioshack.com/products/rad ... 5717010885

I only changed hdmi_group=1 and hdmi_mode=8 in config.txt

It's working well but I am getting this sync issue as seen in this video. https://www.youtube.com/watch?v=VLBHWZV1dZ4

Could a custom hdmi_cvt or hdmi_timings setting fix the vertical scrolling? The picture is sharp and looks great with natural scanlines. It just wont stop scrolling up.