TVSERVICE(1)

NAME
tvservice - get and set information from attached displays

SYNOPSIS
tvservice [-a] [-c mode aspect p] [-d filename] [-e group mode drive] [-j] [-l] [-m group] [-M] [-n] [-o] [-p] [-s] [-t] [-v id]
tvservice -h
tvservice --help

DESCRIPTION
tvservice is a command line application used to get and set information about the display, targeted mainly at HDMI video and audio. Typing tvservice by itself will display a list of available command line options.

OPTIONS

-a, --audio
    Shows the current settings for the audio mode, including channels, sample rate and sample size.

-c, --sdtvon "mode aspect [P]"
    Power on the SDTV (composite output) with the specified mode, PAL or NSTC, and the specified aspect, 4:3, 14:9, 16:9. The optional “P” parameter can be used to specify progressive mode.

-d, --dumpid filename
    Save the current EDID to the specified filename. You can then use edid-decode(1) to display the data in a human readable form. See [EDID] for more information on the EDID contents.

-e, --explicit "group mode drive"
    Power on the HDMI display with the specified settings. The group option can be one of CEA, DMT, CEA_3D_SBS, CEA_3D_TB, CEA_3D_FP, or CEA_3D_FS; mode is one of the modes returned from the --modes option. Finally, drive can be HDMI or DVI.

-j, --json
    When used in combination with the --modes option, displays the mode information in JSON format.

-l, --list
    Lists all attached displays and their display ID.

-m, --modes group
    Shows a list of display modes available in the specified group, which can be either CEA or DMT.

-M, --monitor
    Monitors for any HDMI events, for example unplugging or attaching.

-n, --name
    Extracts the display name from the EDID data and shows it.

-o, --off
    Powers off the display output.

    Important Note: Powering off the output using this command will also destroy any framebuffers/dispmanx layers associated with the display. These are NOT re-established with a subsequent power on, so will result in a blank screen.

    A better option is to use the vcgencmd(1) display_power option, as this will retain any framebuffers, so when the power is turned back on the display will be the returned to the previous power on state.

-p, --preferred
    Power on the HDMI output with preferred settings.

-s, --status
    Shows the current settings for the display mode, including mode, resolution, and frequency.

-t, --ntsc
    Use 59.94Hz (NTSC frequency) rather than 60Hz for HDMI mode.

-v, --device id
    Specifies the ID of the device to use; see the output of --list for available IDs.

SEE ALSO
vcgencmd(1), edid-decode(1)

Full documentation at [SOURCE].

REFERENCES

[EDID]
    https://en.wikipedia.org/wiki/Extended_Display_Identification_Data

[SOURCE]
    https://www.raspberrypi.org/documentation/raspbian/applications/tvservice.md