Force resolution to 1080i (old TV)

  • Hi need some help, as I got stuck.



    Librelec 9.2.8 on Raspberry Pi 4.


    I want to have 1080i resolution and (since it isn’t detected) checked tvservice:



    LibreELEC-WZ:~ # tvservice -m CEA


    Group CEA has 9 modes:


    mode 1: 640x480 @ 60Hz 4:3, clock:25MHz progressive

    mode 2: 720x480 @ 60Hz 4:3, clock:27MHz progressive

    mode 3: 720x480 @ 60Hz 16:9, clock:27MHz progressive

    mode 4: 1280x720 @ 60Hz 16:9, clock:74MHz progressive

    mode 5: 1920x1080 @ 60Hz 16:9, clock:74MHz interlaced

    mode 17: 720x576 @ 50Hz 4:3, clock:27MHz progressive

    mode 18: 720x576 @ 50Hz 16:9, clock:27MHz progressive

    mode 19: 1280x720 @ 50Hz 16:9, clock:74MHz progressive

    (native) mode 20: 1920x1080 @ 50Hz 16:9, clock:74MHz interlaced



    When using


    tvservice -e “CEA 5”


    the TV reports 1080i, but the libreelec Gui is not adapting to the higher resolution and therefore just like a window in the upper left corner of the TV, while the rest stays black (see picture). And I cannot change the display resolution in the settings to the 1080i, there is no option.



    So I added in config.txt the following:


    hdmi_group=1

    hdmi_mode=5

    hdmi_force_hotplug=1



    Distroconfig.txt is included and contains these two entries:


    dtoverlay=vc4-fkms-v3d

    disable_overscan=1



    But then libreelec starts always in 720p, kind of ignoring my setting. If I try then tvservice -e “CEA 5” same thing happens, Gui not scaling, while TV changes into 1080i.



    Is there something I could try in addition?

  • Kodi always and only outputs progressive. Interlaced 25/29.97/30 media requires 50/59.94/60Hz modes from the TV so that each interlaced frame (two half frames) can be rendered progressively (in two progressive frames). Hence the highest resolution Kodi can output is 720p (mode 4) and there is no 1080i to select.

  • Kodi always and only outputs progressive. Interlaced 25/29.97/30 media requires 50/59.94/60Hz modes from the TV so that each interlaced frame (two half frames) can be rendered progressively (in two progressive frames). Hence the highest resolution Kodi can output is 720p (mode 4) and there is no 1080i to select.


    I've run LibreElec on a Pi via an HDMI->HD-SDI converter in 1080i25 output mode as a 1080i25 file player for broadcast TV. Kodi is presumably deinterlacing any interlaced media to 1080p50 and then the Pi is interlacing its output to 1080i25 (retaining the 50Hz motion), so it's not 1080i25 native - but it does retain the 1080i25 50Hz motion on its output?


    (1080i25 = 1080/50i)