sane-v4l(5)

📦
version 1.4.0 · 5 versions
, in centos-stream 10, fedora 43, fedora 44, opensuse-leap 16.0

✨ sane-v4l ✨

okay bestie, gather round, because this is the manual page for sane-v4l(5) — yes the whole SANE Scanner Access Now Easy situation, and yes I am going to make you care about it. 💅

💖 NAME 💖

sane-v4l — the SANE interface for the Video for Linux API, aka your lil bridge between scanning software and video cameras, periodt.

🌸 DESCRIPTION 🌸

So the sane-v4l library implements a SANE (that's Scanner Access Now Easy, iconic name honestly) backend, and what it does is give you generic access to video cameras and similar equipment using the V4L (Video for Linux) API. Generic access. Cameras. Vibes. 🎀

⚠️ This is ALPHA software. Really! Important features are missing and there are lots of bugs. No cap, do not come for me. 😭

The code is currently only tested on a Linux 2.4 system with a Hauppauge WinTV video card. That's it. That's the whole test matrix. Bestie it is giving ✨chaotic science experiment✨ and we respect it anyway. 🦋

🎀 DEVICE NAMES 🎀

This backend expects device names of the form:

special

Where special is the UNIX path-name for the special device that corresponds to the v4l device. And listen — the special device name must be a v4l device or a symlink to such a device. Non-negotiable. 💅

For example, such a device name could be /dev/video0 or /dev/bttv0. Slay. 🔥

🌈 CONFIGURATION 🌈

The contents of the v4l.conf file is a list of device names that correspond to v4l devices. Empty lines and lines starting with a hash mark (#) are ignored — those are your lil ghost lines, they're just there for decoration. 🫶

A sample configuration file is shown below:

/dev/bttv0
# this is a comment
/dev/video3

See? Cute. Comment goes brrr, devices go brrr. 🍓

🧚 FILES 🧚

  • /etc/sane.d/v4l.conf — the backend configuration file (see also description of SANE_CONFIG_DIR below, yes I'm making you scroll, it's right there tho 💜)
  • /usr/lib64/sane/libsane-v4l.a — the static library implementing this backend
  • /usr/lib64/sane/libsane-v4l.so — the shared library implementing this backend (present on systems that support dynamic loading, iykyk)

⭐ ENVIRONMENT ⭐

  • SANE_CONFIG_DIR — this environment variable specifies the list of directories that may contain the configuration file. On *NIX systems, the directories are separated by a colon (:), and under OS/2, they are separated by a semi-colon (;). If this variable is not set, the configuration file is searched in two default directories: first, the current working directory (".") and then in /etc/sane.d.

And here's the lil plot twist 👑: if the value of the environment variable ends with the directory separator character, then the default directories are searched after the explicitly specified directories. For example, setting SANE_CONFIG_DIR to "/tmp/config:" would result in directories tmp/config, ., and /etc/sane.d being searched (in this order). The way that colon just changes the whole search order?? obsessed. 🦋

  • SANE_DEBUG_V4L — if the library was compiled with debug support enabled, this environment variable controls the debug level for this backend. E.g., a value of 128 requests all debug output to be printed. Smaller levels reduce verbosity. So like, 128 is the "tell me EVERYTHING bestie" setting and everything below is the "okay chill" setting. 💅

👑 AUTHOR 👑

Juergen G. Schimmer, Henning Meier-Geinitz

(pay respects, these are the main characters 🫶)

💀 BUGS 💀

ok so. The tea:

  • If more than one video card is present, a crash may occur. Not me being dramatic, that's literally what it says. 🙈
  • Frequency and geometry selection is missing. Gone. Not there. 😭

Send bug reports to the SANE mailing list: sane-devel@alioth-lists.debian.net. You must be subscribed to the list to send mail. That's the rule, bestie, no lurking and mailing. See http://www.sane-project.org/mailing-lists.html for details. ✨

🔥 SEE ALSO 🔥

and that's the whole page, you ate it, you read it, you understand the V4L backend now 💖

this has been sane-v4l(5), from the SANE Scanner Access Now Easy collection, dated 14 Jul 2008 — yes it's vintage, yes it still slays, mwah 💅🎀

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