Beyond Linux® From Scratch (System V Edition) - Version r12.0-1306-wip

Chapter 42. Multimedia Libraries and Drivers

v4l-utils-1.26.1

Introduction to v4l-utils

v4l-utils provides a series of utilities for media devices, allowing the ability to handle the proprietary formats available from most webcams (libv4l), and providing tools to test V4L devices.

[Note]

Note

Development versions of BLFS may not build or run some packages properly if LFS or dependencies have been updated since the most recent stable versions of the books.

Package Information

v4l-utils Dependencies

Recommended

alsa-lib-1.2.10, GLU-9.0.3, libjpeg-turbo-3.0.1, and (Qt-5.15.12 or qt-alternate-5.15.12)

Optional

Doxygen-1.10.0, SDL2-2.28.5, both LLVM-17.0.6 (with Clang and target BPF) and libbpf (for infrared remote control decoders based on BPF), and SDL_image

Installation of v4l-utils

[Note]

Note

If you've installed both LLVM and libbpf (not in BLFS), either enable the BPF target (via -DLLVM_TARGETS_TO_BUILD=) building LLVM, or disable the infrared remote control decoders based on BPF: 

sed '/^ir_bpf_enabled/s/=.*/= false/' \
    -i utils/keytable/meson.build

Install v4l-utils by running the following commands: 

mkdir build &&
cd    build &&

meson setup --prefix=/usr          \
            -Ddoxygen-doc=disabled \
            -Dgconv=disabled       \
            --buildtype=release    .. &&
ninja

This package does not come with a test suite.

Now, as the root user: 

ninja install

If you also wish to install the contrib programs, add: 

for prog in v4l2gl v4l2grab
do
   cp -v contrib/test/$prog /usr/bin
done

Command Explanations

-Dgconv=disabled: This switch disables the erroneous installation of gconv-modules that would break glibc.

Contents

Installed Programs: cec-compliance, cec-ctl, cec-follower, cx18-ctl, decode_tm6000, dvb-fe-tool, dvb-format-convert, dvbv5-daemon, dvbv5-scan, dvbv5-zap, ir-ctl, ir-keytable, ivtv-ctl, media-ctl, qv4l2, qvidcap, rds-ctl, v4l2-compliance, v4l2-ctl, v4l2-dbg, v4l2gl, v4l2grab, and v4l2-sysfs-path
Installed Library: libdvbv5.so, libv4l1.so, libv4l2.so, libv4l2rds.so, libv4lconvert.so, v4l1compat.so, and v4l2convert.so
Installed Directories: /etc/rc_keymaps, /lib/udev/rc_keymaps, /usr/include/libdvbv5, and /usr/lib/libv4l

Short Descriptions

cx18-ctl

is a tool to handle cx18 based devices

decode_tm6000

decodes multiplexed formats from TM5600/TM6000 USB devices

dvb-fe-tool

is a command line tool for digital TV services

dvb-format-convert

is a tool meant to convert among different file formats. It is compliant with version 5 of the DVB API

dvbv5-scan

is a command line frequency scanning tool for digital TV services that are compliant with version 5 of the DVB API

dvbv5-zap

is a command line tuning tool for digital TV services that is compliant with version 5 of the DVB API

ir-keytable

is a tool that lists the Remote Controller devices, allows one to get/set IR keycode/scancode tables, test events generated by IR, and to adjust other Remote Controller options

ivtv-ctl

is a utility that can control many card settings, like changing the inputs from tuner to svideo or composite, setting video resolution or changing video mode (PAL, SECAM, NTSC)

media-ctl

is a utility used to configure V4L2 devices

qv4l2

is used to test video4linux capture devices

qvidcap

is used to capture video from a V4L2 device

rds-ctl

is a utility for decoding raw RDS data from V4L2 Radio devices and offers simple ways to access the received RDS information

v4l2-compliance

is a compliance test tool

v4l2-ctl

is a tool to control v4l2 controls from the cmdline

v4l2-dbg

is a tool to directly get and set registers of v4l2 devices

v4l2gl

captures images using libv4l and stores them as PPM files

v4l2grab

captures images using libv4l and stores them as PPM files, while also allowing for additional options such as setting the amount of frames captured and saving the file as a RAW file

v4l2-sysfs-path

checks the media devices installed on a machine and the corresponding device nodes