configure

#!/bin/sh
#
# FFmpeg configure script
#
# Copyright (c) 2000-2002 Fabrice Bellard
# Copyright (c) 2005-2008 Diego Biurrun
# Copyright (c) 2005-2008 Mans Rullgard
#

# Prevent locale nonsense from breaking basic text processing.
LC_ALL=C
export LC_ALL

# make sure we are running under a compatible shell
# try to make this part work with most shells

try_exec(){
    echo "Trying shell $1"
    type "$1" > /dev/null 2>&1 && exec "$@"
}

unset foo
(: ${foo%%bar}) 2> /dev/null
E1="$?"

(: ${foo?}) 2> /dev/null
E2="$?"

if test "$E1" != 0 || test "$E2" = 0; then
    echo "Broken shell detected.  Trying alternatives."
    export FF_CONF_EXEC
    if test "0$FF_CONF_EXEC" -lt 1; then
        FF_CONF_EXEC=1
        try_exec bash "$0" "$@"
    fi
    if test "0$FF_CONF_EXEC" -lt 2; then
        FF_CONF_EXEC=2
        try_exec ksh "$0" "$@"
    fi
    if test "0$FF_CONF_EXEC" -lt 3; then
        FF_CONF_EXEC=3
        try_exec /usr/xpg4/bin/sh "$0" "$@"
    fi
    echo "No compatible shell script interpreter found."
    echo "This configure script requires a POSIX-compatible shell"
    echo "such as bash or ksh."
    echo "THIS IS NOT A BUG IN FFMPEG, DO NOT REPORT IT AS SUCH."
    echo "Instead, install a working POSIX-compatible shell."
    echo "Disabling this configure test will create a broken FFmpeg."
    if test "$BASH_VERSION" = '2.04.0(1)-release'; then
        echo "This bash version ($BASH_VERSION) is broken on your platform."
        echo "Upgrade to a later version if available."
    fi
    exit 1
fi

show_help(){
cat <<EOF
Usage: configure [options]
Options: [defaults in brackets after descriptions]

Standard options:
  --help                   print this message
  --logfile=FILE           log tests and output to FILE [config.err]
  --disable-logging        do not log configure debug information
  --prefix=PREFIX          install in PREFIX [$prefix]
  --bindir=DIR             install binaries in DIR [PREFIX/bin]
  --datadir=DIR            install data files in DIR [PREFIX/share/ffmpeg]
  --libdir=DIR             install libs in DIR [PREFIX/lib]
  --shlibdir=DIR           install shared libs in DIR [PREFIX/lib]
  --incdir=DIR             install includes in DIR [PREFIX/include]
  --mandir=DIR             install man page in DIR [PREFIX/share/man]

Configuration options:
  --disable-static         do not build static libraries [no]
  --enable-shared          build shared libraries [no]
  --enable-gpl             allow use of GPL code, the resulting libs
                           and binaries will be under GPL [no]
  --enable-version3        upgrade (L)GPL to version 3 [no]
  --enable-nonfree         allow use of nonfree code, the resulting libs
                           and binaries will be unredistributable [no]
  --disable-doc            do not build documentation
  --disable-ffmpeg         disable ffmpeg build
  --disable-ffplay         disable ffplay build
  --disable-ffprobe        disable ffprobe build
  --disable-ffserver       disable ffserver build
  --disable-avdevice       disable libavdevice build
  --disable-avcodec        disable libavcodec build
  --disable-avformat       disable libavformat build
  --disable-swscale        disable libswscale build
  --enable-postproc        enable GPLed postprocessing support [no]
  --enable-avfilter        video filter support [no]
  --enable-avfilter-lavf   video filters dependent on avformat [no]
  --enable-beosthreads     use BeOS threads [no]
  --enable-os2threads      use OS/2 threads [no]
  --enable-pthreads        use pthreads [no]
  --enable-w32threads      use Win32 threads [no]
  --enable-x11grab         enable X11 grabbing [no]
  --disable-network        disable network support [no]
  --disable-mpegaudio-hp   faster (but less accurate) MPEG audio decoding [no]
  --enable-gray            enable full grayscale support (slower color)
  --disable-swscale-alpha  disable alpha channel support in swscale
  --disable-fastdiv        disable table-based division
  --enable-small           optimize for size instead of speed
  --disable-aandct         disable AAN DCT code
  --disable-dct            disable DCT code
  --disable-fft            disable FFT code
  --disable-golomb         disable Golomb code
  --disable-lpc            disable LPC code
  --disable-mdct           disable MDCT code
  --disable-rdft           disable RDFT code
  --disable-vaapi          disable VAAPI code
  --disable-vdpau          disable VDPAU code
  --disable-dxva2          disable DXVA2 code
  --enable-runtime-cpudetect detect cpu capabilities at runtime (bigger binary)
  --enable-hardcoded-tables use hardcoded tables instead of runtime generation
  --enable-memalign-hack   emulate memalign, interferes with memory debuggers
  --enable-beos-netserver  enable BeOS netserver
  --disable-everything     disable all components listed below
  --disable-encoder=NAME   disable encoder NAME
  --enable-encoder=NAME    enable encoder NAME
  --disable-encoders       disable all encoders
  --disable-decoder=NAME   disable decoder NAME
  --enable-decoder=NAME    enable decoder NAME
  --disable-decoders       disable all decoders
  --disable-hwaccel=NAME   disable hwaccel NAME
  --enable-hwaccel=NAME    enable hwaccel NAME
  --disable-hwaccels       disable all hwaccels
  --disable-muxer=NAME     disable muxer NAME
  --enable-muxer=NAME      enable muxer NAME
  --disable-muxers         disable all muxers
  --disable-demuxer=NAME   disable demuxer NAME
  --enable-demuxer=NAME    enable demuxer NAME
  --disable-demuxers       disable all demuxers
  --enable-parser=NAME     enable parser NAME
  --disable-parser=NAME    disable parser NAME
  --disable-parsers        disable all parsers
  --enable-bsf=NAME        enable bitstream filter NAME
  --disable-bsf=NAME       disable bitstream filter NAME
  --disable-bsfs           disable all bitstream filters
  --enable-protocol=NAME   enable protocol NAME
  --disable-protocol=NAME  disable protocol NAME
  --disable-protocols      disable all protocols
  --disable-indev=NAME     disable input device NAME
  --disable-outdev=NAME    disable output device NAME
  --disable-indevs         disable input devices
  --disable-outdevs        disable output devices
  --disable-devices        disable all devices
  --enable-filter=NAME     enable filter NAME
  --disable-filter=NAME    disable filter NAME
  --disable-filters        disable all filters
  --list-decoders          show all available decoders
  --list-encoders          show all available encoders
  --list-hwaccels          show all available hardware accelerators
  --list-muxers            show all available muxers
  --list-demuxers          show all available demuxers
  --list-parsers           show all available parsers
  --list-protocols         show all available protocols
  --list-bsfs              show all available bitstream filters
  --list-indevs            show all available input devices
  --list-outdevs           show all available output devices
  --list-filters           show all available filters

External library support:
  --enable-avisynth        enable reading of AVISynth script files [no]
  --enable-bzlib           enable bzlib [autodetect]
  --enable-libopencore-amrnb enable AMR-NB de/encoding via libopencore-amrnb [no]
  --enable-libopencore-amrwb enable AMR-WB decoding via libopencore-amrwb [no]
  --enable-libdc1394       enable IIDC-1394 grabbing using libdc1394
                           and libraw1394 [no]
  --enable-libdirac        enable Dirac support via libdirac [no]
  --enable-libfaac         enable FAAC support via libfaac [no]
  --enable-libfaad         enable FAAD support via libfaad [no]
  --enable-libfaadbin      open libfaad.so.0 at runtime [no]
  --enable-libgsm          enable GSM support via libgsm [no]
  --enable-libmp3lame      enable MP3 encoding via libmp3lame [no]
  --enable-libnut          enable NUT (de)muxing via libnut,
                           native (de)muxer exists [no]
  --enable-libopenjpeg     enable JPEG 2000 decoding via OpenJPEG [no]
  --enable-libschroedinger enable Dirac support via libschroedinger [no]
  --enable-libspeex        enable Speex decoding via libspeex [no]
  --enable-libtheora       enable Theora encoding via libtheora [no]
  --enable-libvorbis       enable Vorbis encoding via libvorbis,
                           native implementation exists [no]
  --enable-libx264         enable H.264 encoding via x264 [no]
  --enable-libxvid         enable Xvid encoding via xvidcore,
                           native MPEG-4/Xvid encoder exists [no]
  --enable-mlib            enable Sun medialib [no]
  --enable-zlib            enable zlib [autodetect]

Advanced options (experts only):
  --source-path=PATH       path to source code [$source_path]
  --cross-prefix=PREFIX    use PREFIX for compilation tools [$cross_prefix]
  --enable-cross-compile   assume a cross-compiler is used
  --sysroot=PATH           root of cross-build tree
  --sysinclude=PATH        location of cross-build system headers
  --target-os=OS           compiler targets OS [$target_os]
  --target-exec=CMD        command to run executables on target
  --target-path=DIR        path to view of build directory on target
  --nm=NM                  use nm tool
  --as=AS                  use assembler AS [$as_default]
  --cc=CC                  use C compiler CC [$cc_default]
  --ld=LD                  use linker LD
  --host-cc=HOSTCC         use host C compiler HOSTCC
  --host-cflags=HCFLAGS    use HCFLAGS when compiling for host
  --host-ldflags=HLDFLAGS  use HLDFLAGS when linking for host
  --host-libs=HLIBS        use libs HLIBS when linking for host
  --extra-cflags=ECFLAGS   add ECFLAGS to CFLAGS [$CFLAGS]
  --extra-ldflags=ELDFLAGS add ELDFLAGS to LDFLAGS [$LDFLAGS]
  --extra-libs=ELIBS       add ELIBS [$ELIBS]
  --extra-version=STRING   version string suffix []
  --build-suffix=SUFFIX    library name suffix []
  --arch=ARCH              select architecture [$arch]
  --cpu=CPU                select the minimum required CPU (affects
                           instruction selection, may crash on older CPUs)
  --enable-powerpc-perf    enable performance report on PPC
                           (requires enabling PMC)
  --disable-asm            disable all assembler optimizations
  --disable-altivec        disable AltiVec optimizations
  --disable-amd3dnow       disable 3DNow! optimizations
  --disable-amd3dnowext    disable 3DNow! extended optimizations
  --disable-mmx            disable MMX optimizations
  --disable-mmx2           disable MMX2 optimizations
  --disable-sse            disable SSE optimizations
  --disable-ssse3          disable SSSE3 optimizations
  --disable-armv5te        disable armv5te optimizations
  --disable-armv6          disable armv6 optimizations
  --disable-armv6t2        disable armv6t2 optimizations
  --disable-armvfp         disable ARM VFP optimizations
  --disable-iwmmxt         disable iwmmxt optimizations
  --disable-mmi            disable MMI optimizations
  --disable-neon           disable neon optimizations
  --disable-vis            disable VIS optimizations
  --disable-yasm           disable use of yasm assembler
  --enable-pic             build position-independent code
  --malloc-prefix=PFX      prefix malloc and related names with PFX
  --enable-sram            allow use of on-chip SRAM

Developer options (useful when working on FFmpeg itself):
  --disable-debug          disable debugging symbols
  --enable-debug=LEVEL     set the debug level [$debuglevel]
  --enable-gprof           enable profiling with gprof [$gprof]
  --disable-optimizations  disable compiler optimizations
  --enable-extra-warnings  enable more compiler warnings
  --disable-stripping      disable stripping of executables and shared libraries
  --samples=PATH           location of test samples for FATE

NOTE: Object files are built at the place where configure is launched.
EOF
  exit 0
}

log(){
    echo "$@" >> $logfile
}

log_file(){
    log BEGIN $1
    pr -n -t $1 >> $logfile
    log END $1
}

echolog(){
    log "$@"
    echo "$@"
}

die(){
    echolog "$@"
    cat <<EOF

If you think configure made a mistake, make sure you are using the latest
version from SVN.  If the latest version fails, report the problem to the
ffmpeg-user@mplayerhq.hu mailing list or IRC #ffmpeg on irc.freenode.net.
EOF
    if disabled logging; then
        cat <<EOF
Rerun configure with logging enabled (do not use --disable-logging), and
include the log this produces with your report.
EOF
    else
cat <<EOF
Include the log file "$logfile" produced by configure as this will help
solving the problem.
EOF
    fi
    exit 1
}

# Avoid locale weirdness, besides we really just want to translate ASCII.
toupper(){
    echo "$@" | tr abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ
}

tolower(){
    echo "$@" | tr ABCDEFGHIJKLMNOPQRSTUVWXYZ abcdefghijklmnopqrstuvwxyz
}

c_escape(){
    echo "$*" | sed 's/["\\]/\\\0/g'
}

sh_quote(){
    v=$(echo "$1" | sed "s/'/'\\\\''/g")
    test "$v" = "${v#*[ |&;<>()$\`\\\"\'*?\[\]#~=%]}" || v="'$v'"
    echo "$v"
}

filter(){
    pat=$1
    shift
    for v; do
        eval "case $v in $pat) echo $v ;; esac"
    done
}

map(){
    m=$1
    shift
    for v; do eval $m; done
}

set_all(){
    value=$1
    shift
    for var in $*; do
        eval $var=$value
    done
}

set_weak(){
    value=$1
    shift
    for var; do
        eval : \${$var:=$value}
    done
}

pushvar(){
    for var in $*; do
        eval level=\${${var}_level:=0}
        eval ${var}_${level}="\$$var"
        eval ${var}_level=$(($level+1))
    done
}

popvar(){
    for var in $*; do
        eval level=\${${var}_level:-0}
        test $level = 0 && continue
        eval level=$(($level-1))
        eval $var="\${${var}_${level}}"
        eval ${var}_level=$level
        eval unset ${var}_${level}
    done
}

enable(){
    set_all yes $*
}

disable(){
    set_all no $*
}

enable_weak(){
    set_weak yes $*
}

disable_weak(){
    set_weak no $*
}

enable_safe(){
    for var; do
        enable $(echo "$var" | sed 's/[^A-Za-z0-9_]/_/g')
    done
}

disable_safe(){
    for var; do
        disable $(echo "$var" | sed 's/[^A-Za-z0-9_]/_/g')
    done
}

do_enable_deep(){
    for var; do
        enabled $var && continue
        eval sel="\$${var}_select"
        eval sgs="\$${var}_suggest"
        pushvar var sgs
        enable_deep $sel
        popvar sgs
        enable_deep_weak $sgs
        popvar var
    done
}

enable_deep(){
    do_enable_deep $*
    enable $*
}

enable_deep_weak(){
    do_enable_deep $*
    enable_weak $*
}

enabled(){
    test "${1#!}" = "$1" && op== || op=!=
    eval test "x\$${1#!}" $op "xyes"
}

disabled(){
    test "${1#!}" = "$1" && op== || op=!=
    eval test "x\$${1#!}" $op "xno"
}

enabled_all(){
    for opt; do
        enabled $opt || return 1
    done
}

disabled_all(){
    for opt; do
        disabled $opt || return 1
    done
}

enabled_any(){
    for opt; do
        enabled $opt && return 0
    done
}

disabled_any(){
    for opt; do
        disabled $opt && return 0
    done
    return 1
}

set_default(){
    for opt; do
        eval : \${$opt:=\$${opt}_default}
    done
}

is_in(){
    value=$1
    shift
    for var in $*; do
        [ $var = $value ] && return 0
    done
    return 1
}

check_deps(){
    for cfg; do
        cfg="${cfg#!}"
        enabled ${cfg}_checking && die "Circular dependency for $cfg."
        disabled ${cfg}_checking && continue
        enable ${cfg}_checking

        eval dep_all="\$${cfg}_deps"
        eval dep_any="\$${cfg}_deps_any"
        eval dep_sel="\$${cfg}_select"
        eval dep_sgs="\$${cfg}_suggest"
        eval dep_ifa="\$${cfg}_if"
        eval dep_ifn="\$${cfg}_if_any"

        pushvar cfg dep_all dep_any dep_sel dep_sgs dep_ifa dep_ifn
        check_deps $dep_all $dep_any $dep_sel $dep_sgs $dep_ifa $dep_ifn
        popvar cfg dep_all dep_any dep_sel dep_sgs dep_ifa dep_ifn

        [ -n "$dep_ifa" ] && { enabled_all $dep_ifa && enable_weak $cfg; }
        [ -n "$dep_ifn" ] && { enabled_any $dep_ifn && enable_weak $cfg; }
        enabled_all  $dep_all || disable $cfg
        enabled_any  $dep_any || disable $cfg
        disabled_any $dep_sel && disable $cfg

        if enabled $cfg; then
            eval dep_extralibs="\$${cfg}_extralibs"
            test -n "$dep_extralibs" && add_extralibs $dep_extralibs
            enable_deep $dep_sel
            enable_deep_weak $dep_sgs
        fi

        disable ${cfg}_checking
    done
}

print_config(){
    pfx=$1
    header=$2
    makefile=$3
    shift 3
    for cfg; do
        ucname="$(toupper $cfg)"
        if enabled $cfg; then
            echo "#define ${pfx}${ucname} 1" >> $header
            echo "${pfx}${ucname}=yes" >> $makefile
        else
            echo "#define ${pfx}${ucname} 0" >> $header
            echo "!${pfx}${ucname}=yes" >> $makefile
        fi
    done
}

flags_saved(){
    (: ${SAVE_CFLAGS?}) 2> /dev/null
}

save_flags(){
    flags_saved && return
    SAVE_CFLAGS="$CFLAGS"
    SAVE_LDFLAGS="$LDFLAGS"
    SAVE_extralibs="$extralibs"
}

restore_flags(){
    flags_saved || return
    CFLAGS="$SAVE_CFLAGS"
    LDFLAGS="$SAVE_LDFLAGS"
    extralibs="$SAVE_extralibs"
    unset SAVE_CFLAGS
    unset SAVE_LDFLAGS
    unset SAVE_extralibs
}

temp_cflags(){
    save_flags
    CFLAGS="$CFLAGS $*"
}

temp_ldflags(){
    save_flags
    LDFLAGS="$LDFLAGS $*"
}

temp_extralibs(){
    save_flags
    extralibs="$extralibs $*"
}

append(){
    var=$1
    shift
    flags_saved && eval "SAVE_$var=\"\$SAVE_$var $*\""
    eval "$var=\"\$$var $*\""
}

add_cppflags(){
    append CPPFLAGS $($filter_cppflags "$@")
}

add_cflags(){
    append CFLAGS $($filter_cflags "$@")
}

add_asflags(){
    append ASFLAGS $($filter_asflags "$@")
}

add_ldflags(){
    append LDFLAGS "$@"
}

add_extralibs(){
    append extralibs "$@"
}

check_cmd(){
    log "$@"
    "$@" >> $logfile 2>&1
}

check_cc(){
    log check_cc "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $cc $CPPFLAGS $CFLAGS "$@" -c -o $TMPO $TMPC
}

check_cpp(){
    log check_cpp "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $cc $CPPFLAGS $CFLAGS "$@" -E -o $TMPO $TMPC
}

check_as(){
    log check_as "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $as $CPPFLAGS $ASFLAGS "$@" -c -o $TMPO $TMPC
}

check_asm(){
    log check_asm "$@"
    name="$1"
    code="$2"
    shift 2
    disable $name
    check_as "$@" <<EOF && enable $name
void foo(void){ __asm__ volatile($code); }
EOF
}

check_yasm(){
    log check_yasm "$@"
    echo "$1" > $TMPS
    log_file $TMPS
    shift 1
    check_cmd $yasmexe $YASMFLAGS "$@" -o $TMPO $TMPS
}

check_ld(){
    log check_ld "$@"
    flags=''
    libs=''
    for f; do
        test "${f}" = "${f#-l}" && flags="$flags $f" || libs="$libs $f"
    done
    check_cc $($filter_cflags $flags) || return
    check_cmd $ld $LDFLAGS $flags -o $TMPE $TMPO $extralibs $libs
}

check_cppflags(){
    log check_cppflags "$@"
    set -- $($filter_cppflags "$@")
    check_cc "$@" <<EOF && append CPPFLAGS "$@"
int x;
EOF
}

check_cflags(){
    log check_cflags "$@"
    set -- $($filter_cflags "$@")
    check_cc "$@" <<EOF && append CFLAGS "$@"
int x;
EOF
}

test_ldflags(){
    log test_ldflags "$@"
    check_ld "$@" <<EOF
int main(void){ return 0; }
EOF
}

check_ldflags(){
    log check_ldflags "$@"
    test_ldflags "$@" && add_ldflags "$@"
}

check_header(){
    log check_header "$@"
    header=$1
    shift
    disable_safe $header
    check_cpp "$@" <<EOF && enable_safe $header
#include <$header>
int x;
EOF
}

check_func(){
    log check_func "$@"
    func=$1
    shift
    disable $func
    check_ld "$@" <<EOF && enable $func
extern int $func();
int main(void){ $func(); }
EOF
}

check_mathfunc(){
    log check_mathfunc "$@"
    func=$1
    shift
    disable $func
    check_ld "$@" <<EOF && enable $func
#include <math.h>
float foo(float f) { return $func(f); }
int main(void){ return 0; }
EOF
}

check_func_headers(){
    log check_func_headers "$@"
    headers=$1
    func=$2
    shift 2
    disable $func
    incs=""
    for hdr in $headers; do
        incs="$incs
#include <$hdr>"
    done
    check_ld "$@" <<EOF && enable $func && enable_safe $headers
$incs
int main(int argc, char **argv){
    return (long) $func;
}
EOF
}

check_cpp_condition(){
    log check_cpp_condition "$@"
    header=$1
    condition=$2
    shift 2
    check_cpp $($filter_cppflags "$@") <<EOF
#include <$header>
#if !($condition)
#error "unsatisfied condition: $condition"
#endif
EOF
}

check_lib(){
    log check_lib "$@"
    header="$1"
    func="$2"
    shift 2
    temp_extralibs "$@"
    check_header $header && check_func $func && add_extralibs "$@"
    err=$?
    restore_flags
    return $err
}

check_lib2(){
    log check_lib2 "$@"
    headers="$1"
    func="$2"
    shift 2
    check_func_headers "$headers" $func "$@" && add_extralibs "$@"
}

check_exec(){
    check_ld "$@" && { enabled cross_compile || $TMPE >> $logfile 2>&1; }
}

check_exec_crash(){
    code=$(cat)

    # exit() is not async signal safe.  _Exit (C99) and _exit (POSIX)
    # are safe but may not be available everywhere.  Thus we use
    # raise(SIGTERM) instead.  The check is run in a subshell so we
    # can redirect the "Terminated" message from the shell.  SIGBUS
    # is not defined by standard C so it is used conditionally.

    (check_exec "$@") >> $logfile 2>&1 <<EOF
#include <signal.h>
static void sighandler(int sig){
    raise(SIGTERM);
}
int main(void){
    signal(SIGILL, sighandler);
    signal(SIGFPE, sighandler);
    signal(SIGSEGV, sighandler);
#ifdef SIGBUS
    signal(SIGBUS, sighandler);
#endif
    { $code }
}
EOF
}

check_type(){
    log check_type "$@"
    headers=$1
    type=$2
    shift 2
    disable_safe "$type"
    incs=""
    for hdr in $headers; do
        incs="$incs
#include <$hdr>"
    done
    check_cc "$@" <<EOF && enable_safe "$type"
$incs
$type v;
EOF
}

check_struct(){
    log check_type "$@"
    headers=$1
    struct=$2
    member=$3
    shift 3
    disable_safe "${struct}_${member}"
    incs=""
    for hdr in $headers; do
        incs="$incs
#include <$hdr>"
    done
    check_cc "$@" <<EOF && enable_safe "${struct}_${member}"
$incs
const void *p = &(($struct *)0)->$member;
EOF
}

require(){
    name="$1"
    header="$2"
    func="$3"
    shift 3
    check_lib $header $func "$@" || die "ERROR: $name not found"
}

require2(){
    name="$1"
    headers="$2"
    func="$3"
    shift 3
    check_lib2 "$headers" $func "$@" || die "ERROR: $name not found"
}

check_foo_config(){
    cfg=$1
    pkg=$2
    header=$3
    func=$4
    shift 4
    disable $cfg
    check_cmd ${pkg}-config --version
    err=$?
    if test "$err" = 0; then
        temp_cflags $(${pkg}-config --cflags)
        temp_extralibs $(${pkg}-config --libs)
        check_lib "$@" $header $func && enable $cfg
    fi
    return $err
}

check_host_cc(){
    log check_host_cc "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $host_cc $host_cflags "$@" -c -o $TMPO $TMPC
}

check_host_cflags(){
    log check_host_cflags "$@"
    check_host_cc "$@" <<EOF && append host_cflags "$@"
int x;
EOF
}

apply(){
    file=$1
    shift
    "$@" < "$file" > "$file.tmp" && mv "$file.tmp" "$file" || rm "$file.tmp"
}

cp_if_changed(){
    cmp -s "$1" "$2" &&
        echo "$2 is unchanged" ||
        cp -f "$1" "$2"
}

# CONFIG_LIST contains configurable options, while HAVE_LIST is for
# system-dependent things.

COMPONENT_LIST="
    bsfs
    decoders
    demuxers
    encoders
    filters
    hwaccels
    indevs
    muxers
    outdevs
    parsers
    protocols
"

CONFIG_LIST="
    $COMPONENT_LIST
    aandct
    avcodec
    avdevice
    avfilter
    avfilter_lavf
    avformat
    avisynth
    beos_netserver
    bzlib
    dct
    doc
    dwt
    dxva2
    fastdiv
    ffmpeg
    ffplay
    ffprobe
    ffserver
    fft
    golomb
    gpl
    gprof
    gray
    h264dsp
    hardcoded_tables
    libdc1394
    libdirac
    libfaac
    libfaad
    libfaadbin
    libgsm
    libmp3lame
    libnut
    libopencore_amrnb
    libopencore_amrwb
    libopenjpeg
    libschroedinger
    libspeex
    libtheora
    libvorbis
    libx264
    libxvid
    lpc
    lsp
    mdct
    memalign_hack
    mlib
    mpegaudio_hp
    network
    nonfree
    pic
    postproc
    powerpc_perf
    rdft
    runtime_cpudetect
    shared
    small
    sram
    static
    swscale
    swscale_alpha
    vaapi
    vdpau
    version3
    x11grab
    zlib
"

THREADS_LIST='
    beosthreads
    os2threads
    pthreads
    w32threads
'

ARCH_LIST='
    alpha
    arm
    avr32
    avr32_ap
    avr32_uc
    bfin
    ia64
    m68k
    mips
    mips64
    parisc
    ppc
    ppc64
    s390
    sh4
    sparc
    sparc64
    tomi
    x86
    x86_32
    x86_64
'

ARCH_EXT_LIST='
    altivec
    amd3dnow
    amd3dnowext
    armv5te
    armv6
    armv6t2
    armvfp
    iwmmxt
    mmi
    mmx
    mmx2
    neon
    ppc4xx
    sse