Bugzilla Bug 244918

libv4l is a library that performs pixel format conversion and is required for
using most webcams supported by kernel 2.6.27's gspca driver (i.e. most USB
webcams in existence).
libv4l also provides a couple of wrapper libraries that can be listed in
LD_PRELOAD to automatically perform the conversion in legacy and binary apps.

There are a number of binary-only applications that use webcams - most
prominently, skype. Without a 32-bit libv4l, there is no way to use a gspca
webcam in skype. Therefore, it would be extremely useful if libv4l were added
to app-emulation/emul-linux-x86-medialibs

Created an attachment (id=170252) [details]
libv4l-0.5.3.tbz2

libv4l-0.5.3.tbz2, compiled in a current 32-bit emul-chroot

actually the libv4l automatically builds 32bit bins on an amd64 profile so
that's no need for this (unless you want to split)

(In reply to comment #2)
> actually the libv4l automatically builds 32bit bins on an amd64 profile so
> that's no need for this (unless you want to split)

No, the ebuild that is in the portage tree builds only 64-bit on amd64.
(Currently, as a temporary workaround for skype users, there is a libv4l ebuild
attached to bug 240090 that builds both 32-bit and 64-bit on amd64, but I am
pretty sure it will not be going into the tree.)

Alex, thanks for all your work on libv4l packaging. Assigning to amd64 team who
can decide to add this to the emul-linux stuff or vote for building the 32-bit
compatibility in libv4l (i.e. commit something like you posted in bug 240090)

can i ask the status of 32 bit multilib ebuild?

we are stuck unofficially to 0.5.1, i can bump to 0.5.7 manually but atm gentoo
lacks lots of webcam support for 32bits apps.

Judging by the inactivity, it looks like amd64 team is not interested in adding
this to emul-linux-x86-*.

However, that may be for the best - libv4l is a fast-moving target, new
versions are released quite often and fix serious bugs for certain webcam
models. So at this point, I think adding a multilib libv4l ebuild to the tree
is the best solution.

Created an attachment (id=175262) [details]
proposed libv4l-0.5.7-r1.ebuild with multilib

I found this problem, i think it's because of gcc-4.3.1

 * Building multilib libv4l for ABIs: x86 amd64
make -C libv4lconvert V4L2_LIB_VERSION=0.5.7 all
make[1]: Entering directory
`/var/tmp/portage/media-libs/libv4l-0.5.7-r1/work/libv4l-0.5.7-x86/libv4lconvert'
x86_64-pc-linux-gnu-gcc -c -MMD -I../include -I../../../../linux/include
-fvisibility=hidden -fPIC -O2 -mtune=core2 -march=core2 -pipe
-fomit-frame-pointer -msse4.1 -o libv4lconvert.o libv4lconvert.c
x86_64-pc-linux-gnu-gcc -c -MMD -I../include -I../../../../linux/include
-fvisibility=hidden -fPIC -O2 -mtune=core2 -march=core2 -pipe
-fomit-frame-pointer -msse4.1 -o tinyjpeg.o tinyjpeg.c
x86_64-pc-linux-gnu-gcc -c -MMD -I../include -I../../../../linux/include
-fvisibility=hidden -fPIC -O2 -mtune=core2 -march=core2 -pipe
-fomit-frame-pointer -msse4.1 -o sn9c10x.o sn9c10x.c
x86_64-pc-linux-gnu-gcc -c -MMD -I../include -I../../../../linux/include
-fvisibility=hidden -fPIC -O2 -mtune=core2 -march=core2 -pipe
-fomit-frame-pointer -msse4.1 -o pac207.o pac207.c
x86_64-pc-linux-gnu-gcc -c -MMD -I../include -I../../../../linux/include
-fvisibility=hidden -fPIC -O2 -mtune=core2 -march=core2 -pipe
-fomit-frame-pointer -msse4.1 -o flip.o flip.c
x86_64-pc-linux-gnu-gcc -c -MMD -I../include -I../../../../linux/include
-fvisibility=hidden -fPIC -O2 -mtune=core2 -march=core2 -pipe
-fomit-frame-pointer -msse4.1 -o crop.o crop.c
x86_64-pc-linux-gnu-gcc -c -MMD -I../include -I../../../../linux/include
-fvisibility=hidden -fPIC -O2 -mtune=core2 -march=core2 -pipe
-fomit-frame-pointer -msse4.1 -o jidctflt.o jidctflt.c
x86_64-pc-linux-gnu-gcc -c -MMD -I../include -I../../../../linux/include
-fvisibility=hidden -fPIC -O2 -mtune=core2 -march=core2 -pipe
-fomit-frame-pointer -msse4.1 -o spca561-decompress.o spca561-decompress.c
x86_64-pc-linux-gnu-gcc -c -MMD -I../include -I../../../../linux/include
-fvisibility=hidden -fPIC -O2 -mtune=core2 -march=core2 -pipe
-fomit-frame-pointer -msse4.1 -o rgbyuv.o rgbyuv.c
x86_64-pc-linux-gnu-gcc -c -MMD -I../include -I../../../../linux/include
-fvisibility=hidden -fPIC -O2 -mtune=core2 -march=core2 -pipe
-fomit-frame-pointer -msse4.1 -o spca501.o spca501.c
x86_64-pc-linux-gnu-gcc -c -MMD -I../include -I../../../../linux/include
-fvisibility=hidden -fPIC -O2 -mtune=core2 -march=core2 -pipe
-fomit-frame-pointer -msse4.1 -o bayer.o bayer.c
libv4lconvert.c: In function 'v4lconvert_create':
libv4lconvert.c:121: warning: cast from pointer to integer of different size
libv4lconvert.c:121: warning: cast from pointer to integer of different size
libv4lconvert.c:121: warning: cast from pointer to integer of different size
libv4lconvert.c:121: warning: cast from pointer to integer of different size
libv4lconvert.c:121: warning: cast from pointer to integer of different size
libv4lconvert.c:121: warning: cast from pointer to integer of different size
libv4lconvert.c:121: warning: cast from pointer to integer of different size
libv4lconvert.c:121: warning: cast from pointer to integer of different size
libv4lconvert.c:121: warning: cast from pointer to integer of different size
libv4lconvert.c:121: warning: cast from pointer to integer of different size
libv4lconvert.c:121: warning: cast from pointer to integer of different size
libv4lconvert.c:121: warning: cast from pointer to integer of different size
libv4lconvert.c:125: warning: cast from pointer to integer of different size
libv4lconvert.c:125: warning: cast from pointer to integer of different size
libv4lconvert.c:125: warning: cast from pointer to integer of different size
libv4lconvert.c:125: warning: cast from pointer to integer of different size
libv4lconvert.c:125: warning: cast from pointer to integer of different size
libv4lconvert.c:125: warning: cast from pointer to integer of different size
libv4lconvert.c:125: warning: cast from pointer to integer of different size
libv4lconvert.c:125: warning: cast from pointer to integer of different size
libv4lconvert.c:125: warning: cast from pointer to integer of different size
libv4lconvert.c:125: warning: cast from pointer to integer of different size
libv4lconvert.c:125: warning: cast from pointer to integer of different size
libv4lconvert.c:125: warning: cast from pointer to integer of different size
x86_64-pc-linux-gnu-gcc -shared -Wl,-O1 -Wl,-soname,libv4lconvert.so.0 -o
libv4lconvert.so.0 libv4lconvert.o tinyjpeg.o sn9c10x.o pac207.o flip.o crop.o
jidctflt.o spca561-decompress.o rgbyuv.o spca501.o bayer.o
collect2: ld terminated with signal 11 [Segmentation fault]
/usr/lib/gcc/x86_64-pc-linux-gnu/4.3.1/../../../../x86_64-pc-linux-gnu/bin/ld:
i386:x86-64 architecture of input file `libv4lconvert.o' is incompatible with
i386 output
/usr/lib/gcc/x86_64-pc-linux-gnu/4.3.1/../../../../x86_64-pc-linux-gnu/bin/ld:
i



 emerge --info
Portage 2.1.4.5 (default/linux/amd64/2008.0/desktop, gcc-4.3.1, glibc-2.7-r2,
2.6.27-gentoo-r7 x86_64)
=================================================================
System uname: 2.6.27-gentoo-r7 x86_64 Intel(R) Core(TM)2 Quad CPU Q9300 @
2.50GHz
Timestamp of tree: Sun, 21 Dec 2008 11:30:01 +0000
distcc 3.0 x86_64-pc-linux-gnu [enabled]
app-shells/bash:     3.2_p33
dev-java/java-config: 1.3.7-r1, 2.1.6-r1
dev-lang/python:     2.5.2-r7
dev-python/pycrypto: 2.0.1-r6
dev-util/cmake:      2.4.6-r1
sys-apps/baselayout: 2.0.0
sys-apps/openrc:     0.3.0-r1
sys-apps/sandbox:    1.2.18.1-r2
sys-devel/autoconf:  2.13, 2.61-r2
sys-devel/automake:  1.5, 1.7.9-r1, 1.8.5-r3, 1.9.6-r2, 1.10.1-r1
sys-devel/binutils:  2.18-r3
sys-devel/gcc-config: 1.4.0-r4
sys-devel/libtool:   1.5.26
virtual/os-headers:  2.6.23-r3
ACCEPT_KEYWORDS="amd64"
CBUILD="x86_64-pc-linux-gnu"
CFLAGS="-O2 -mtune=core2 -march=core2 -pipe -fomit-frame-pointer -msse4.1"
CHOST="x86_64-pc-linux-gnu"
CONFIG_PROTECT="/etc /var/bind /var/lib/hsqldb /var/qmail/alias
/var/qmail/control"
CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/env.d/java/
/etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release
/etc/php/apache2-php5/ext-active/ /etc/php/cgi-php5/ext-active/
/etc/php/cli-php5/ext-active/ /etc/revdep-rebuild /etc/splash /etc/terminfo
/etc/texmf/web2c /etc/udev/rules.d"
CXXFLAGS="-O2 -mtune=core2 -march=core2 -pipe -fomit-frame-pointer -msse4.1"
DISTDIR="/usr/portage/distfiles"
FEATURES="buildpkg_ collision-protect distcc distlocks maketest
metadata-transfer parallel-fetch sandbox sfperms strict unmerge-orphans
userfetch"
GENTOO_MIRRORS="ftp://pandemonium.tiscali.de/pub/gentoo/
http://mirror.switch.ch/ftp/mirror/gentoo/"
LANG="it_IT.UTF-8"
LDFLAGS="-Wl,-O1"
LINGUAS="it it_IT en en_US en_GB es es_ES"
MAKEOPTS="-j10"
PKGDIR="/usr/portage/packages"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --compress
--force --whole-file --delete --stats --timeout=180 --exclude=/distfiles
--exclude=/local --exclude=/packages"
PORTAGE_TMPDIR="/var/tmp"
PORTDIR="/usr/portage"
PORTDIR_OVERLAY="/usr/local/portage"
SYNC="rsync://rsync.gentoo.org/gentoo-portage"
USE="16bit 64bit X X509 a52 aac aalib acl acpi aiglx aim alsa amd64 amr amrnb
amrwb apache2 apm applet audiofile avi bash-completion berkdb bidi bitmap-fonts
bittorrent bluetooth bonobo branding browserplugin bzip2 cairo caps cdda cddb
cdio cdparanoia cdr cgi chroot cli cracklib crypt css ctype cups curl dbus
dc1394 deskbar divx dlloader dri dts dv dvb dvd dvdr dvdread dvi dynamic eds em
emboss emovix enca encode esd ethereal evo evolution exif expat faillog fam
fame fbsplash ffmpeg firefox flac flash fontconfig foomaticdb fortran fping
freetds freetype ftp gaim gcc4 gd gdbm gdm gedit gencertdaily geoip gif gimp
gimpprint glitz glut gmail gmedia gmp gno gnome gnome-keyring gnutls gpac
gphoto2 gpm gsf gsm gstreamer gtk gtk2 gtkhtml guile hal hash hddtemp howl
iconv id3tag idea idn ieee1394 imagemagick imap imlib ipod isdnlog ithreads
java jpeg kerberos lame lcms libcaca libclamav libedit libnotify libwww live
lm_sensors logrotate logwatch lzo lzw lzw-tiff mad maildir maildrop matroska
md5sum mhash midi mikmod mime ming mjpeg mmx mmxext mng mono motif mozilla
mozsvg mp2 mp3 mpeg mplayer mpm-prefork msn mudflap multilib musepack
musicbrainz mysql nautilus ncurses nemesei network networking new-login nfs ng
nls nptl nptlonly nsplugin nvidia obex offensive ogg oggvorbis openal opengl
openmp opensslcrypt optimisememory pam pcre pdf pdflib perl php pidgin png pnm
pop posix ppds pppd prediction python qmail qt3support quicktime quotas radio
readline realmedia recode reflection regex remote rtc samba scanner sdl sensord
server session simplexml skins slang smp sms sndfile sni sound sox spamassassin
speex spell spl sqlite srt sse sse2 sse3 ssl ssse2 ssse3 startup-notification
stream subtitles svg symlink sysfs syslog tcltk tcpd teletext templates tetex
theora threads threadsafe tiff tivo toolbar tools tracker truetype
truetype-fonts twolame type1-fonts udev unicode upnp usb v4l v4l2 vcd vhosts
vim-syntax vlm vorbis wavpack wifi wmf wmp wxgtk1 wxwindows x264 xanim
xcomposite xml xml2 xmlreader xmlwriter xorg xpm xscreensaver xulrunner xv xvid
xvmc zip zlib" ALSA_CARDS="intel8x0 usb-audio" ALSA_PCM_PLUGINS="adpcm alaw
asym copy dmix dshare dsnoop empty extplug file hooks iec958 ioplug ladspa
lfloat linear meter mmap_emul mulaw multi null plug rate route share shm
softvol" APACHE2_MODULES="actions alias auth_basic auth_digest authn_anon
authn_dbd authn_dbm authn_default authn_file authz_dbm authz_default
authz_groupfile authz_host authz_owner authz_user autoindex cache dav dav_fs
dav_lock dbd deflate dir disk_cache env expires ext_filter file_cache filter
headers ident imagemap include info log_config logio mem_cache mime mime_magic
negotiation proxy proxy_ajp proxy_balancer proxy_connect proxy_http rewrite
setenvif so speling status unique_id userdir usertrack vhost_alias"
CAMERAS="spca50x" ELIBC="glibc" INPUT_DEVICES="keyboard mouse" KERNEL="linux"
LINGUAS="it it_IT en en_US en_GB es es_ES" USERLAND="GNU" VIDEO_CARDS="nvidia"
Unset:  CPPFLAGS, CTARGET, EMERGE_DEFAULT_OPTS, FFLAGS, INSTALL_MASK, LC_ALL,
PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS

(In reply to comment #8)
> I found this problem, i think it's because of gcc-4.3.1

I emerged libv4l-4.5.7-r1 with your CFLAGS and LDFLAGS, your version of
portage, and gcc-4.3.2, and I cannot reproduce the problem. I suspect something
is wrong either with your distcc setup or with your gcc.

Could you please:
1. Check if you can reproduce the bug without distcc and ccache (meaning
FEATURES="-distcc -ccache")
2. Try updating from gcc-4.3.1 to 4.3.2

Solved disabling distcc

Hi! I wanted to know the real status of this bug. I have installed libv4l with
the multilib flag on on my amd64 and all runs well, actually this is the only
way I found for using my camera under Skype. If the bug is resolved now, please
add multilib to the "official" libv4l ebuild - otherwise many gentoo'ers must
first discover this bug report and do the effort of installing the ebuild here
in an overlay, etc. - I bet many people don't know about this bug and are angry
why their camera doesn't work.... (since gspcav1 doesn't compile any more you
know)...

The quickest way to work around this is to do...

CFLAGS="-O2 -m32" ABI=x86 emerge --oneshot libv4l

But obviously this isn't ideal and it won't work if you need a 64-bit version
as well. I just used this to fix Skype and it worked a treat. The solution
wasn't obvious though and I think that Gentoo should set this up automatically.

Errr sorry, ignore the --oneshot.

I am also wanting for this lib to be a part of
app-emulation/emul-linux-x86-medialibs, since I'm use an old webcam with skype
and I think that skype isn't planning to launch a 64-bits version for linux.

By the way, the advice of James Le Cuirot on comment #12 works perfectly but I
think it is not a good way to do these webcams works with skype.

+1 vote for the libv4l ebuild with multilib.

I propose to add these lines to src_install() in libv4l-0.5.8.ebuild

echo "LDPATH=\"/usr/$(get_libdir)\"" >> 99libv4l
doenvd 99libv4l

In this way we do not need to use LD_PRELOAD every time we exec a video app.

Created an attachment (id=196022) [details]
proposed libv4l-0.5.8-r1.ebuild to add libv4l to env.d

So, what is the status of 32bit libv4l on ADM64 now?

You can find a mulitlib variant here:
http://bugs.gentoo.org/show_bug.cgi?id=283746