Template:ArticleMigratedFromOSDKUG Template:ArticleMainWriter Template:ReviewersList Template:ArticleFirstDraftVersion
You can configure the video output mode and resolution from weston.ini configuration file located in:
/etc/xdg/weston/weston.ini
For more details refer to the ubuntu weston.ini manpage[1]
1. Standard video mode[edit source]
If you want to set a standard video mode (1080, 720, VGA, ...), you have to provide the video mode in “resolution” format.
Example with a 1280x720 resolution In weston.ini file, modify the connector section with the resolution (here #HDMI connector):
[output]
name=HDMI-A-1
#mode=preferred
mode=1280x720
Then restart Weston or reboot the board.
2. Specific video mode[edit source]
If you want to set a particular video mode (for example specifying a refresh frequency), you have to provide the video mode in “modeline” format.
2.1. With cvt tool[edit source]
If cvt is present in your system, you can enter for instance:
cvt 1280 720 60 # 1280x720 59.86 Hz (CVT 0.92M9) hsync: 44.77 kHz; pclk: 74.50 MHz Modeline "1280x720_60.00" 74.50 1280 1344 1472 1664 720 723 728 748 -hsync +vsync
then add this modeline result in weston.ini
[output]
name=HDMI-A-1
#mode=preferred
mode=74.50 1280 1344 1472 1664 720 723 728 748 -hsync +vsync
Then restart Weston or reboot the board.
For more details about cvt, refer to the ubuntu cvt manpage[2]
2.2. Without cvt tool[edit source]
Example using 1920x1080@30Hz
First, you have to retrieve the modeline parameters for the mode you need:
$ echo 7 > /sys/module/drm/parameters/debug $ systemctl stop weston $ systemctl start weston $ dmesg | grep modeline # ... # [ 386.662671] [drm:drm_mode_debug_printmodeline], Modeline 43:"1920x1080" 25 74250 1920 2448 2492 2640 1080 1084 1089 1125 0x40 0x5 # [ 386.662699] [drm:drm_mode_debug_printmodeline], Modeline 40:"1920x1080" 24 74250 1920 2558 2602 2750 1080 1084 1089 1125 0x40 0x5 # [ 386.662726] [drm:drm_mode_debug_printmodeline], Modeline 41:"1920x1080" 24 74176 1920 2558 2602 2750 1080 1084 1089 1125 0x40 0x5 # [ 386.662753] [drm:drm_mode_debug_printmodeline], Modeline 39:"1920x1080" 30 74176 1920 2008 2052 2200 1080 1084 1089 1125 0x40 0x5
As listed on the last line, the parameters for 1920x1080@30 are:
74176 1920 2008 2052 2200 1080 1084 1089 1125 0x40 0x5
Remove the two last parameters (0x40 0x5) and divide the first parameter by 1000 (MHz->kHz), which gives:
74.176 1920 2008 2052 2200 1080 1084 1089 1125
Retrieve the hsync & vsync polarity of this mode from modetest:
$ modetest
# Connectors:
# id encoder status type size (mm) modes encoders
# 9 8 connected HDMI-A 710x400 31 8
# modes:
# name refresh (Hz) hdisp hss hse htot vdisp vss vse vtot)
# 1920x1080 50 1920 2448 2492 2640 1080 1084 1089 1125 flags: phsync, pvsync; type: preferred, driver
# 1920x1080 60 1920 2008 2052 2200 1080 1084 1089 1125 flags: phsync, pvsync; type: driver
# 1920x1080 60 1920 2008 2052 2200 1080 1084 1089 1125 flags: phsync, pvsync; type: driver
# 1920x1080 30 1920 2008 2052 2200 1080 1084 1089 1125 flags: phsync, pvsync; type: driver
# ...
The polarity for 1920x1080@30 is "phsync, pvsync" (p stands for positive, n for negative). Append the polarity with the (+)(-)hsync (+)(-)vsync format. Here:
+hsync +vsync
The complete mode is:
74.176 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync
Then, in weston.ini, modify the connector section with the provided parameters:
[output]
name=HDMI-A-1
#mode=preferred
mode=74.176 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync
Then restart Weston or reboot the board.
3. References[edit source]
- ↑ http://manpages.ubuntu.com/manpages/wily/man5/weston.ini.5.html ubuntu weston.ini manpage
- ↑ http://manpages.ubuntu.com/manpages/xenial/en/man1/cvt.1.html ubuntu cvt manpage