NAME

muxsa-kvm2png — takes a series of screenshots from a virtual machine

SYNOPSIS

| muxsa-kvm2png

DESCRIPTION

muxsa-kvm2png is part of muxsa (MUltipleXer for Slides and Audio), a collection of Linux tools for efficiently creating video files from presentation slides and background narration. For an overview on muxsa, see /usr/share/doc/muxsa/howto.txt and https://git-nks-public.tik.uni-stuttgart.de/edu/muxsa.

muxsa-kvm2png assumes that a virtual machine under Linux/KVM with spicy(1) display is running, typically with some slide presentation software, such as Powerpoint in Windows or Libreoffice in Windows or Linux, running on it. It will repeatedly take screnshots and press the PageDown key, until some kind of "end of presentation" screen is detected.

Options

(none)

FILES

~/.muxsarc: Per-user default configuration file. Will be sourced by bash and can be used to define the environment variables listed below.
0000.png, 0001.png, 0002.png, ...: Default file names of the screenshots taken. See environment variable MUXSA_KVM2PNG_SLIDE_PREFIX below.

ENVIRONMENT

MUXSA_KVM2PNG_VM_NAME: The name of the virual machine, as can be shown with virsh -c qemu:///system list. Default value: win10-office
MUXSA_KVM2PNG_SIZE_X: Desired width of the screenshots to be taken, in pixels. muxsa-kvm2png will invoke xdotool(1) to resize the spicy(1) window, if needed. Default value: 1920
MUXSA_KVM2PNG_SIZE_Y: Desired height of the screenshots to be taken, in pixels. Default value: 1080
MUXSA_KVM2PNG_EXTRA_X: Extra window width, to account for menus and window decoration. If needed, muxsa-kvm2png will invoke xdotool(1) to resize the spicy(1) window to a witdh of MUXSA_KVM2PNG_SIZE_X + MUXSA_KVM2PNG_EXTRA_X. Default value: 0
MUXSA_KVM2PNG_EXTRA_Y: Extra window height, to account for menus and window decoration. If needed, muxsa-kvm2png will invoke xdotool(1) to resize the spicy(1) window to a height of MUXSA_KVM2PNG_SIZE_Y + MUXSA_KVM2PNG_EXTRA_Y. Default value: 0 ; in many cases a value of 28 is useful.
MUXSA_KVM2PNG_SLIDE_PREFIX: The screenshots will be saved in files named with this prefix, followed by a four-digit number and .png. Default value: "" (empty), i.e., screenshots will be saved as 0000.png, 0001.png, 0002.png, ... in the current directory.
MUXSA_KVM2PNG_SLIDE_NUMBER_START: First number to be used as the four digit sequence number for the screenshot file names. Default value: 0 (will be padded to four digits automatically).
MUXSA_KVM2PNG_SLIDE_NUMBER_END: Last number to be used as the four digit sequence number for the screenshot file names. Default value: 9999
MUXSA_KVM2PNG_FORCE_OVERWRITE: If set to 1, existing screenshot files will be overwritten without asking the user for confirmation. Otherwise, the program will abort if a file already exists. Default value: "" (empty)
MUXSA_KVM2PNG_BUGFIX_SHOOT_TWICE: There have been bug reports, that with some versions of KVM/libvirt/spicy, the screenshots were sometimes garbled. As a workaround, if this variable is set to 1, always take two screenshots in a row, discard of the first one, and only use the second one, which always seemed to be intact in these scenarios. Default value: "" (empty)
MUXSA_KVM2PNG_SLEEP: Sleep time in seconds to wait after emulating a PageDown keystroke, before taking the next screenshot. Adjust to a longer interval if your slide presentation uses slide transition effects that take longer to settle. Default value: 3 (seconds).
MUXSA_KVM2PNG_MD5_LAST_SLIDE: Stop taking screenshots after a .png file with this md5sum(1) output has been shot. Default value: 092eb68a91b4d2a73833f00a01dc5cb0 ("End of slide show. click to exit." screen of Powerpoint, screenshot taken at 1920x1080 pixels).

BUGS

See: https://git-nks-public.tik.uni-stuttgart.de/edu/muxsa/issues

AUTHOR

Sebastian Kiesel sebastian.kiesel@tik.uni-stuttgart.de

4.4 KiB Raw Blame History