configure

#!/bin/sh
#
# Libav 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 LIBAV, DO NOT REPORT IT AS SUCH."
    echo "Instead, install a working POSIX-compatible shell."
    echo "Disabling this configure test will create a broken Libav."
    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

test -d /usr/xpg4/bin && PATH=/usr/xpg4/bin:$PATH

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

Help options:
  --help                   print this message
  --list-decoders          show all available decoders
  --list-encoders          show all available encoders
  --list-hwaccels          show all available hardware accelerators
  --list-demuxers          show all available demuxers
  --list-muxers            show all available muxers
  --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

Standard options:
  --logfile=FILE           log tests and output to FILE [config.log]
  --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/avconv]
  --docdir=DIR             install documentation in DIR [PREFIX/share/doc/libav]
  --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]

Licensing options:
  --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]

Configuration options:
  --disable-static         do not build static libraries [no]
  --enable-shared          build shared libraries [no]
  --enable-small           optimize for size instead of speed
  --enable-runtime-cpudetect detect cpu capabilities at runtime (bigger binary)
  --enable-gray            enable full grayscale support (slower color)
  --disable-swscale-alpha  disable alpha channel support in swscale
  --disable-all            disable building components, libraries and programs

Program options:
  --disable-programs       do not build command line programs
  --disable-avconv         disable avconv build
  --disable-avplay         disable avplay build
  --disable-avprobe        disable avprobe build
  --disable-avserver       disable avserver build

Component options:
  --disable-doc            do not build documentation
  --disable-avdevice       disable libavdevice build
  --disable-avcodec        disable libavcodec build
  --disable-avformat       disable libavformat build
  --disable-avutil         disable libavutil build
  --disable-swscale        disable libswscale build
  --disable-avfilter       disable video filter support [no]
  --disable-avresample     disable libavresample build [no]
  --disable-pthreads       disable pthreads [auto]
  --disable-w32threads     disable Win32 threads [auto]
  --disable-network        disable network support [no]
  --disable-dct            disable DCT code
  --disable-error-resilience disable error resilience code
  --disable-lsp            disable LSP code
  --disable-lzo            disable LZO decoder code
  --disable-mdct           disable MDCT code
  --disable-rdft           disable RDFT code
  --disable-fft            disable FFT code

Hardware accelerators:
  --enable-dxva2           enable DXVA2 code
  --enable-vaapi           enable VAAPI code
  --enable-vda             enable VDA code
  --enable-vdpau           enable VDPAU code

Individual component options:
  --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
  --enable-indev=NAME      enable input device NAME
  --disable-indev=NAME     disable input device NAME
  --disable-indevs         disable input devices
  --enable-outdev=NAME     enable output device NAME
  --disable-outdev=NAME    disable output device NAME
  --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

External library support:
  --enable-avisynth        enable reading of AviSynth script files [no]
  --enable-bzlib           enable bzlib [autodetect]
  --enable-frei0r          enable frei0r video filtering
  --enable-gnutls          enable gnutls [no]
  --enable-libbs2b         enable bs2b DSP library [no]
  --enable-libcdio         enable audio CD grabbing with libcdio
  --enable-libdc1394       enable IIDC-1394 grabbing using libdc1394
                           and libraw1394 [no]
  --enable-libfaac         enable AAC encoding via libfaac [no]
  --enable-libfdk-aac      enable AAC de/encoding via libfdk-aac [no]
  --enable-libfreetype     enable libfreetype [no]
  --enable-libgsm          enable GSM de/encoding via libgsm [no]
  --enable-libilbc         enable iLBC de/encoding via libilbc [no]
  --enable-libmp3lame      enable MP3 encoding via libmp3lame [no]
  --enable-libopencore-amrnb enable AMR-NB de/encoding via libopencore-amrnb [no]
  --enable-libopencore-amrwb enable AMR-WB decoding via libopencore-amrwb [no]
  --enable-libopencv       enable video filtering via libopencv [no]
  --enable-libopenjpeg     enable JPEG 2000 de/encoding via OpenJPEG [no]
  --enable-libopus         enable Opus de/encoding via libopus [no]
  --enable-libpulse        enable Pulseaudio input via libpulse [no]
  --enable-librtmp         enable RTMP[E] support via librtmp [no]
  --enable-libschroedinger enable Dirac de/encoding via libschroedinger [no]
  --enable-libspeex        enable Speex de/encoding via libspeex [no]
  --enable-libtheora       enable Theora encoding via libtheora [no]
  --enable-libtwolame      enable MP2 encoding via libtwolame [no]
  --enable-libvo-aacenc    enable AAC encoding via libvo-aacenc [no]
  --enable-libvo-amrwbenc  enable AMR-WB encoding via libvo-amrwbenc [no]
  --enable-libvorbis       enable Vorbis encoding via libvorbis [no]
  --enable-libvpx          enable VP8 and VP9 de/encoding via libvpx [no]
  --enable-libwavpack      enable wavpack encoding via libwavpack [no]
  --enable-libwebp         enable WebP encoding via libwebp [no]
  --enable-libx264         enable H.264 encoding via x264 [no]
  --enable-libx265         enable HEVC encoding via x265 [no]
  --enable-libxavs         enable AVS encoding via xavs [no]
  --enable-libxvid         enable Xvid encoding via xvidcore,
                           native MPEG-4/Xvid encoder exists [no]
  --enable-openssl         enable openssl [no]
  --enable-x11grab         enable X11 grabbing [no]
  --enable-zlib            enable zlib [autodetect]

Toolchain options:
  --arch=ARCH              select architecture [$arch]
  --cpu=CPU                select the minimum required CPU (affects
                           instruction selection, may crash on older CPUs)
  --cross-prefix=PREFIX    use PREFIX for compilation tools [$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 [$target_os]
  --target-exec=CMD        command to run executables on target
  --target-path=DIR        path to view of build directory on target
  --target-samples=DIR     path to samples directory on target
  --toolchain=NAME         set tool defaults according to NAME
  --pkg-config=PKGCONFIG   use pkg-config tool PKGCONFIG [$pkg_config_default]
  --nm=NM                  use nm tool
  --ar=AR                  use archive tool AR [$ar_default]
  --as=AS                  use assembler AS [$as_default]
  --cc=CC                  use C compiler CC [$cc_default]
  --dep-cc=DEPCC           use dependency generator DEPCC [$cc_default]
  --ld=LD                  use linker LD
  --pkg-config=PKGCONF     use pkg-config PKGCONF [$pkg_config_default]
  --pkg-config-flags=FLAGS pass additional flags to pkgconf []
  --host-cc=HOSTCC         use host C compiler HOSTCC
  --host-cflags=HCFLAGS    use HCFLAGS when compiling for host
  --host-cppflags=HCPPFLAGS use HCPPFLAGS when compiling for host
  --host-ld=HOSTLD         use host linker HOSTLD
  --host-ldflags=HLDFLAGS  use HLDFLAGS when linking for host
  --host-libs=HLIBS        use libs HLIBS when linking for host
  --host-os=OS             compiler host OS [$target_os]
  --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 []
  --optflags=OPTFLAGS      override optimization-related compiler flags
  --build-suffix=SUFFIX    library name suffix []
  --enable-pic             build position-independent code
  --enable-thumb           compile for Thumb instruction set
  --enable-lto             use link-time optimization

Advanced options (experts only):
  --malloc-prefix=PREFIX   prefix malloc and related names with PREFIX
  --disable-symver         disable symbol versioning
  --enable-hardcoded-tables use hardcoded tables instead of runtime generation
  --disable-safe-bitstream-reader
                           disable buffer boundary checking in bitreaders
                           (faster, but may crash)
  --enable-memalign-hack   emulate memalign, interferes with memory debuggers
  --enable-sram            allow use of on-chip SRAM

Optimization options (experts only):
  --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-mmxext         disable MMXEXT optimizations
  --disable-sse            disable SSE optimizations
  --disable-sse2           disable SSE2 optimizations
  --disable-sse3           disable SSE3 optimizations
  --disable-ssse3          disable SSSE3 optimizations
  --disable-sse4           disable SSE4 optimizations
  --disable-sse42          disable SSE4.2 optimizations
  --disable-avx            disable AVX optimizations
  --disable-xop            disable XOP optimizations
  --disable-fma3           disable FMA3 optimizations
  --disable-fma4           disable FMA4 optimizations
  --disable-avx2           disable AVX2 optimizations
  --disable-armv5te        disable armv5te optimizations
  --disable-armv6          disable armv6 optimizations
  --disable-armv6t2        disable armv6t2 optimizations
  --disable-vfp            disable VFP optimizations
  --disable-neon           disable NEON optimizations
  --disable-inline-asm     disable use of inline assembler
  --disable-yasm           disable use of yasm assembler

Developer options (useful when working on Libav itself):
  --disable-debug          disable debugging symbols
  --enable-debug=LEVEL     set the debug level [$debuglevel]
  --disable-optimizations  disable compiler optimizations
  --enable-extra-warnings  enable more compiler warnings
  --samples=PATH           location of test samples for FATE, if not set use
                           \$LIBAV_SAMPLES at make invocation time.
  --enable-neon-clobber-test check NEON registers for clobbering (should be
                           used only for debugging purposes)
  --enable-xmm-clobber-test check XMM registers for clobbering (Win64-only;
                           should be used only for debugging purposes)
  --enable-random          randomly enable/disable components
  --disable-random
  --enable-random=LIST     randomly enable/disable specific components or
  --disable-random=LIST    component groups. LIST is a comma-separated list
                           of NAME[:PROB] entries where NAME is a component
                           (group) and PROB the probability associated with
                           NAME (default 0.5).
  --random-seed=VALUE      seed value for --enable/disable-random

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

quotes='""'

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

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

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

warn(){
    log "WARNING: $*"
    WARNINGS="${WARNINGS}WARNING: $*\n"
}

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

If you think configure made a mistake, make sure you are using the latest
version from Git.  If the latest version fails, report the problem to the
libav-tools@libav.org mailing list or IRC #libav 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 "$1" | sed "s/'/'\\\\''/g")
    test "x$v" = "x${v#*[!A-Za-z0-9_/.+-]}" || v="'$v'"
    echo "$v"
}

cleanws(){
    echo "$@" | sed 's/^ *//;s/  */ /g;s/ *$//'
}

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

filter_out(){
    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
}

add_suffix(){
    suffix=$1
    shift
    for v; do echo ${v}${suffix}; 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
}

sanitize_var_name(){
    echo $@ | sed 's/[^A-Za-z0-9_]/_/g'
}

set_safe(){
    var=$1
    shift
    eval $(sanitize_var_name "$var")='$*'
}

get_safe(){
    eval echo \$$(sanitize_var_name "$1")
}

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

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

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
}

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

        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
        do_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
            enable_deep $dep_sel
            enable_deep_weak $dep_sgs
        fi

        disable ${cfg}_checking
    done
}

check_deps(){
    unset allopts

    do_check_deps "$@"

    for cfg in $allopts; do
        enabled $cfg || continue
        eval dep_extralibs="\$${cfg}_extralibs"
        test -n "$dep_extralibs" && add_extralibs $dep_extralibs
    done
}

print_config(){
    pfx=$1
    files=$2
    shift 2
    map 'eval echo "$v \${$v:-no}"' "$@" |
    awk "BEGIN { split(\"$files\", files) }
        {
            c = \"$pfx\" toupper(\$1);
            v = \$2;
            sub(/yes/, 1, v);
            sub(/no/,  0, v);
            for (f in files) {
                file = files[f];
                if (file ~ /\\.h\$/) {
                    printf(\"#define %s %d\\n\", c, v) >>file;
                } else if (file ~ /\\.asm\$/) {
                    printf(\"%%define %s %d\\n\", c, v) >>file;
                } else if (file ~ /\\.mak\$/) {
                    n = -v ? \"\" : \"!\";
                    printf(\"%s%s=yes\\n\", n, c) >>file;
                }
            }
        }"
}

print_enabled(){
    suf=$1
    shift
    for v; do
        enabled $v && printf "%s\n" ${v%$suf};
    done
}

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

prepend(){
    var=$1
    shift
    eval "$var=\"$* \$$var\""
}

unique(){
    var=$1
    uniq_list=""
    for tok in $(eval echo \$$var); do
        uniq_list="$(filter_out $tok $uniq_list) $tok"
    done
    eval "$var=\"${uniq_list}\""
}

add_cppflags(){
    append CPPFLAGS "$@"
}

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

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

add_ldflags(){
    append LDFLAGS $($ldflags_filter "$@")
}

add_stripflags(){
    append STRIPFLAGS "$@"
}

add_extralibs(){
    prepend extralibs $($ldflags_filter "$@")
}

add_host_cppflags(){
    append host_cppflags "$@"
}

add_host_cflags(){
    append host_cflags $($host_cflags_filter "$@")
}

add_host_ldflags(){
    append host_ldflags $($host_ldflags_filter "$@")
}

add_compat(){
    append compat_objs $1
    shift
    map 'add_cppflags -D$v' "$@"
}

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

cc_o(){
    eval printf '%s\\n' $CC_O
}

cc_e(){
    eval printf '%s\\n' $CC_E
}

check_cc(){
    log check_cc "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $cc $CPPFLAGS $CFLAGS "$@" $CC_C $(cc_o $TMPO) $TMPC
}

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

as_o(){
    eval printf '%s\\n' $AS_O
}

check_as(){
    log check_as "$@"
    cat > $TMPS
    log_file $TMPS
    check_cmd $as $CPPFLAGS $ASFLAGS "$@" $AS_C $(as_o $TMPO) $TMPS
}

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

check_insn(){
    log check_insn "$@"
    check_inline_asm ${1}_inline "\"$2\""
    echo "$2" | check_as && enable ${1}_external || disable ${1}_external
}

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

ld_o(){
    eval printf '%s\\n' $LD_O
}

check_ld(){
    log check_ld "$@"
    flags=$(filter_out '-l*' "$@")
    libs=$(filter '-l*' "$@")
    check_cc $($cflags_filter $flags) || return
    flags=$($ldflags_filter $flags)
    libs=$($ldflags_filter $libs)
    check_cmd $ld $LDFLAGS $flags $(ld_o $TMPE) $TMPO $libs $extralibs
}

print_include(){
    hdr=$1
    test "${hdr%.h}" = "${hdr}" &&
        echo "#include $hdr"    ||
        echo "#include <$hdr>"
}

check_code(){
    log check_code "$@"
    check=$1
    headers=$2
    code=$3
    shift 3
    {
        for hdr in $headers; do
            print_include $hdr
        done
        echo "int main(void) { $code; return 0; }"
    } | check_$check "$@"
}

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

test_cflags(){
    log test_cflags "$@"
    set -- $($cflags_filter "$@")
    check_cc "$@" <<EOF
int x;
EOF
}

check_cflags(){
    log check_cflags "$@"
    test_cflags "$@" && add_cflags "$@"
}

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

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

test_stripflags(){
    log test_stripflags "$@"
    # call check_cc to get a fresh TMPO
    check_cc <<EOF
int main(void) { return 0; }
EOF
    check_cmd $strip $STRIPFLAGS "$@" $TMPO
}

check_stripflags(){
    log check_stripflags "$@"
    test_stripflags "$@" && add_stripflags "$@"
}

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
    narg=$2
    shift 2
    test $narg = 2 && args="f, g" || args="f"
    disable $func
    check_ld "$@" <<EOF && enable $func
#include <math.h>
float foo(float f, float g) { return $func($args); }
int main(void){ return 0; }
EOF
}

check_func_headers(){
    log check_func_headers "$@"
    headers=$1
    funcs=$2
    shift 2
    {
        for hdr in $headers; do
            print_include $hdr
        done
        for func in $funcs; do
            echo "long check_$func(void) { return (long) $func; }"
        done
        echo "int main(void) { return 0; }"
    } | check_ld "$@" && enable $funcs && enable_safe $headers
}

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

check_lib(){
    log check_lib "$@"
    header="$1"
    func="$2"
    shift 2
    check_header $header && check_func $func "$@" && add_extralibs "$@"
}

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

check_pkg_config(){
    log check_pkg_config "$@"
    pkg="$1"
    headers="$2"
    funcs="$3"
    shift 3
    check_cmd $pkg_config --exists --print-errors $pkg || return
    pkg_cflags=$($pkg_config --cflags $pkg_config_flags $pkg)
    pkg_libs=$($pkg_config --libs $pkg_config_flags $pkg)
    check_func_headers "$headers" "$funcs" $pkg_cflags $pkg_libs "$@" &&
        set_safe ${pkg}_cflags $pkg_cflags   &&
        set_safe ${pkg}_libs   $pkg_libs
}

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 foo(void){
    $code
}
int (*func_ptr)(void) = foo;
int main(void){
    signal(SIGILL, sighandler);
    signal(SIGFPE, sighandler);
    signal(SIGSEGV, sighandler);
#ifdef SIGBUS
    signal(SIGBUS, sighandler);
#endif
    return func_ptr();
}
EOF
}

check_type(){
    log check_type "$@"
    headers=$1
    type=$2
    shift 2
    disable_safe "$type"
    check_code cc "$headers" "$type v" "$@" && enable_safe "$type"
}

check_struct(){
    log check_struct "$@"
    headers=$1
    struct=$2
    member=$3
    shift 3
    disable_safe "${struct}_${member}"
    check_code cc "$headers" "const void *p = &(($struct *)0)->$member" "$@" &&
        enable_safe "${struct}_${member}"
}

check_builtin(){
    log check_builtin "$@"
    name=$1
    headers=$2
    builtin=$3
    shift 3
    disable "$name"
    check_code ld "$headers" "$builtin" "$@" && enable "$name"
}

check_compile_assert(){
    log check_compile_assert "$@"
    name=$1
    headers=$2
    condition=$3
    shift 3
    disable "$name"
    check_code cc "$headers" "char c[2 * !!($condition) - 1]" "$@" && enable "$name"
}

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"
}

require_pkg_config(){
    pkg="$1"
    check_pkg_config "$@" || die "ERROR: $pkg not found"
    add_cflags    $(get_safe ${pkg}_cflags)
    add_extralibs $(get_safe ${pkg}_libs)
}

hostcc_e(){
    eval printf '%s\\n' $HOSTCC_E
}

hostcc_o(){
    eval printf '%s\\n' $HOSTCC_O
}

check_host_cc(){
    log check_host_cc "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $host_cc $host_cflags "$@" $HOSTCC_C $(hostcc_o $TMPO) $TMPC
}

check_host_cpp(){
    log check_host_cpp "$@"
    cat > $TMPC
    log_file $TMPC
    check_cmd $host_cc $HOSTCPPFLAGS $HOSTCFLAGS "$@" $(hostcc_e $TMPO) $TMPC
}

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

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

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

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

cp_if_changed(){
    cmp -s "$1" "$2" && echo "$2 is unchanged" && return
    mkdir -p "$(dirname $2)"
    $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
"

EXAMPLE_LIST="
    avcodec_example
    filter_audio_example
    metadata_example
    output_example
    transcode_aac_example
"

EXTERNAL_LIBRARY_LIST="
    avisynth
    bzlib
    frei0r
    gnutls
    libbs2b
    libcdio
    libdc1394
    libfaac
    libfdk_aac
    libfontconfig
    libfreetype
    libgsm
    libilbc
    libmp3lame
    libopencore_amrnb
    libopencore_amrwb
    libopencv
    libopenjpeg
    libopus
    libpulse
    librtmp
    libschroedinger
    libspeex
    libtheora
    libtwolame
    libvo_aacenc
    libvo_amrwbenc
    libvorbis
    libvpx
    libwavpack
    libwebp
    libx264
    libx265
    libxavs
    libxvid
    openssl
    x11grab
    zlib
"

FEATURE_LIST="
    gray
    hardcoded_tables
    runtime_cpudetect
    safe_bitstream_reader
    shared
    small
    sram
    static
    swscale_alpha
"

HWACCEL_LIST="
    dxva2
    vaapi
    vda
    vdpau
"

LIBRARY_LIST="
    avcodec
    avdevice
    avfilter
    avformat
    avresample
    avutil
    swscale
"

LICENSE_LIST="
    gpl
    nonfree
    version3
"

PROGRAM_LIST="
    avconv
    avplay
    avprobe
    avserver
"

SUBSYSTEM_LIST="
    dct
    doc
    error_resilience
    fft
    lsp
    lzo
    mdct
    network
    rdft
"

CONFIG_LIST="
    $COMPONENT_LIST
    $EXAMPLE_LIST
    $EXTERNAL_LIBRARY_LIST
    $FEATURE_LIST
    $HWACCEL_LIST
    $LICENSE_LIST
    $LIBRARY_LIST
    $PROGRAM_LIST
    $SUBSYSTEM_LIST
    memalign_hack
    neon_clobber_test
    pic
    pod2man
    texi2html
    thumb
    xmm_clobber_test
"

THREADS_LIST="
    pthreads
    w32threads
"

ATOMICS_LIST="
    atomics_gcc
    atomics_suncc
    atomics_win32
"

ARCH_LIST="
    aarch64
    alpha
    arm
    avr32
    avr32_ap
    avr32_uc
    bfin
    ia64
    m68k
    mips
    mips64
    parisc
    ppc
    ppc64
    s390
    sh4
    sparc
    sparc64
    tilegx
    tilepro
    tomi
    x86
    x86_32
    x86_64
"

ARCH_EXT_LIST_ARM="
    armv5te
    armv6
    armv6t2
    armv8
    neon
    vfp
    vfpv3
"

ARCH_EXT_LIST_X86_SIMD="
    amd3dnow
    amd3dnowext
    avx
    avx2
    fma3
    fma4
    mmx
    mmxext
    sse
    sse2
    sse3
    sse4
    sse42
    ssse3
    xop
"

ARCH_EXT_LIST_PPC="
    altivec
    dcbzl
    ldbrx
    ppc4xx
"

ARCH_EXT_LIST_X86="
    $ARCH_EXT_LIST_X86_SIMD
    cpunop
    i686
"

ARCH_EXT_LIST="
    $ARCH_EXT_LIST_ARM
    $ARCH_EXT_LIST_PPC
    $ARCH_EXT_LIST_X86
    loongson