configure

        done
        echo "return 0; }"
    } | check_ld "cxx" "$@" && 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_lib_cpp(){
    log check_lib_cpp "$@"
    headers="$1"
    classes="$2"
    shift 2
    check_class_headers_cpp "$headers" "$classes" "$@" && add_extralibs "$@"
}

check_pkg_config(){
    log check_pkg_config "$@"
    pkgandversion="$1"
    pkg="${1%% *}"
    headers="$2"
    funcs="$3"
    shift 3
    check_cmd $pkg_config --exists --print-errors $pkgandversion || return
    pkg_cflags=$($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 "cc" "$@" && { 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" "cc" "$@" && enable "$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_cpp(){
    name="$1"
    headers="$2"
    classes="$3"
    shift 3
    check_lib_cpp "$headers" "$classes" "$@" || 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)
}

require_libfreetype(){
    log require_libfreetype "$@"
    pkg="freetype2"
    check_cmd $pkg_config --exists --print-errors $pkg \
      || die "ERROR: $pkg not found"
    pkg_cflags=$($pkg_config --cflags $pkg)
    pkg_libs=$($pkg_config --libs $pkg)
    {
        echo "#include <ft2build.h>"
        echo "#include FT_FREETYPE_H"
        echo "long check_func(void) { return (long) FT_Init_FreeType; }"
        echo "int main(void) { return 0; }"
    } | check_ld "cc" $pkg_cflags $pkg_libs \
      && set_safe ${pkg}_cflags $pkg_cflags \
      && set_safe ${pkg}_libs   $pkg_libs \
      || 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="
    avio_reading_example
    avcodec_example
    demuxing_decoding_example
    filter_audio_example
    filtering_audio_example
    filtering_video_example
    metadata_example
    muxing_example
    remuxing_example
    resampling_audio_example
    scaling_video_example
    transcode_aac_example
    transcoding_example
"

EXTERNAL_LIBRARY_LIST="
    avisynth
    bzlib
    crystalhd
    decklink
    fontconfig
    frei0r
    gnutls
    iconv
    ladspa
    libaacplus
    libass
    libbluray
    libcaca
    libcdio
    libcelt
    libdc1394
    libfaac
    libfdk_aac
    libflite
    libfreetype
    libgme
    libgsm
    libiec61883
    libilbc
    libmodplug
    libmp3lame
    libnut
    libopencore_amrnb
    libopencore_amrwb
    libopencv
    libopenjpeg
    libopus
    libpulse
    libquvi
    librtmp
    libschroedinger
    libshine
    libsoxr
    libspeex
    libssh
    libstagefright_h264
    libtheora
    libtwolame
    libutvideo
    libv4l2
    libvidstab
    libvo_aacenc
    libvo_amrwbenc
    libvorbis
    libvpx
    libwavpack
    libwebp
    libx264
    libx265
    libxavs
    libxvid
    libzmq
    libzvbi
    openal
    opencl
    opengl
    openssl
    x11grab
    xlib
    zlib
"

DOCUMENT_LIST="
    doc
    htmlpages
    manpages
    podpages
    txtpages
"

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

HWACCEL_LIST="
    dxva2
    vaapi
    vda
    vdpau
    xvmc
"

LIBRARY_LIST="
    avcodec
    avdevice
    avfilter
    avformat
    avresample
    avutil
    postproc
    swresample
    swscale
"

LICENSE_LIST="
    gpl
    nonfree
    version3
"

PROGRAM_LIST="
    ffplay
    ffprobe
    ffserver
    ffmpeg
"

SUBSYSTEM_LIST="
    dct
    dwt
    error_resilience
    fast_unaligned
    fft
    lsp
    lzo
    mdct
    network
    rdft
"

CONFIG_LIST="
    $COMPONENT_LIST
    $DOCUMENT_LIST
    $EXAMPLE_LIST
    $EXTERNAL_LIBRARY_LIST
    $FEATURE_LIST
    $HWACCEL_LIST
    $LICENSE_LIST
    $LIBRARY_LIST
    $PROGRAM_LIST
    $SUBSYSTEM_LIST
    incompatible_libav_abi
    incompatible_fork_abi
    memalign_hack
    memory_poisoning
    neon_clobber_test
    pic
    pod2man
    raise_major
    thumb
    xmm_clobber_test
"

THREADS_LIST="
    pthreads
    os2threads
    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
    neon
    vfp
    vfpv3
"

ARCH_EXT_LIST_MIPS="
    mipsfpu
    mips32r2
    mipsdspr1
    mipsdspr2
"

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
    $ARCH_EXT_LIST_MIPS
    loongson
"

ARCH_FEATURES="
    aligned_stack
    fast_64bit
    fast_clz
    fast_cmov
    local_aligned_8
    local_aligned_16
"

BUILTIN_LIST="
    atomic_cas_ptr
    machine_rw_barrier
    MemoryBarrier
    mm_empty
    rdtsc
    sarestart
    sync_val_compare_and_swap
"
HAVE_LIST_CMDLINE="
    inline_asm
    symver
    yasm
"

HAVE_LIST_PUB="
    bigendian
    fast_unaligned
    incompatible_libav_abi
    incompatible_fork_abi
"

HEADERS_LIST="
    alsa_asoundlib_h
    altivec_h
    arpa_inet_h
    asm_types_h
    cdio_paranoia_h
    cdio_paranoia_paranoia_h
    CL_cl_h
    dev_bktr_ioctl_bt848_h
    dev_bktr_ioctl_meteor_h
    dev_ic_bt8xx_h
    dev_video_bktr_ioctl_bt848_h
    dev_video_meteor_ioctl_meteor_h
    direct_h
    dlfcn_h
    dxva_h
    ES2_gl_h
    gsm_h
    io_h
    mach_mach_time_h
    machine_ioctl_bt848_h
    machine_ioctl_meteor_h
    malloc_h
    openjpeg_1_5_openjpeg_h
    OpenGL_gl3_h
    poll_h
    sndio_h
    soundcard_h
    sys_mman_h
    sys_param_h
    sys_resource_h
    sys_select_h
    sys_soundcard_h
    sys_time_h
    sys_un_h
    sys_videoio_h
    termios_h
    unistd_h
    windows_h
    winsock2_h
"

MATH_FUNCS="
    atanf
    atan2f
    cbrt
    cbrtf
    cosf
    exp2
    exp2f
    expf
    isinf
    isnan
    ldexpf
    llrint
    llrintf
    log2
    log2f
    log10f
    lrint
    lrintf
    powf
    rint
    round
    roundf
    sinf
    trunc
    truncf
"

SYSTEM_FUNCS="
    access
    aligned_malloc
    clock_gettime
    closesocket
    CommandLineToArgvW
    CryptGenRandom
    dlopen
    fcntl
    flt_lim
    fork
    getaddrinfo
    gethrtime
    getopt
    GetProcessAffinityMask
    GetProcessMemoryInfo
    GetProcessTimes
    getrusage
    getservbyport
    GetSystemTimeAsFileTime
    gettimeofday
    glob
    glXGetProcAddress
    inet_aton
    isatty
    jack_port_get_latency_range
    kbhit
    localtime_r
    lzo1x_999_compress
    mach_absolute_time
    MapViewOfFile
    memalign
    mkstemp
    mmap
    mprotect
    nanosleep
    PeekNamedPipe
    posix_memalign
    pthread_cancel
    sched_getaffinity
    SetConsoleTextAttribute
    setmode
    setrlimit
    Sleep
    strerror_r
    sysconf
    sysctl
    usleep
    VirtualAlloc
    wglGetProcAddress
"

TOOLCHAIN_FEATURES="
    asm_mod_q
    attribute_may_alias
    attribute_packed
    ebp_available
    ebx_available
    gnu_as
    gnu_windres
    ibm_asm
    inline_asm_labels
    inline_asm_nonlocal_labels
    pragma_deprecated
    rsync_contimeout
    symver_asm_label
    symver_gnu_asm
    vfp_args
    xform_asm
    xmm_clobbers
"

TYPES_LIST="
    socklen_t
    struct_addrinfo
    struct_group_source_req
    struct_ip_mreq_source
    struct_ipv6_mreq
    struct_pollfd
    struct_rusage_ru_maxrss
    struct_sctp_event_subscribe
    struct_sockaddr_in6
    struct_sockaddr_sa_len
    struct_sockaddr_storage
    struct_stat_st_mtim_tv_nsec
    struct_v4l2_frmivalenum_discrete
"

HAVE_LIST="
    $ARCH_EXT_LIST
    $(add_suffix _external $ARCH_EXT_LIST)
    $(add_suffix _inline   $ARCH_EXT_LIST)
    $ARCH_FEATURES
    $ATOMICS_LIST
    $BUILTIN_LIST
    $HAVE_LIST_CMDLINE
    $HAVE_LIST_PUB
    $HEADERS_LIST
    $MATH_FUNCS
    $SYSTEM_FUNCS
    $THREADS_LIST
    $TOOLCHAIN_FEATURES
    $TYPES_LIST
    atomics_native
    dos_paths
    libc_msvcrt
    libdc1394_1
    libdc1394_2
    makeinfo
    perl
    pod2man
    sdl
    texi2html
    threads
    vdpau_x11
    xlib
"

# options emitted with CONFIG_ prefix but not available on the command line
CONFIG_EXTRA="
    aandcttables
    ac3dsp
    audio_frame_queue
    dsputil
    exif
    frame_thread_encoder
    gcrypt
    golomb
    gplv3
    h263dsp
    h264chroma
    h264dsp
    h264pred
    h264qpel
    hpeldsp
    huffman
    intrax8
    lgplv3
    llviddsp
    lpc
    mpegaudio
    mpegaudiodsp
    mpegvideo
    mpegvideoenc
    nettle
    rangecoder
    riffdec
    riffenc
    rtpdec
    rtpenc_chain
    sinewin
    videodsp
    vp3dsp
"

CMDLINE_SELECT="
    $ARCH_EXT_LIST
    $CONFIG_LIST
    $HAVE_LIST_CMDLINE
    $THREADS_LIST
    asm
    cross_compile
    debug
    extra_warnings
    logging
    lto
    optimizations
    rpath
    stripping
"

PATHS_LIST="
    bindir
    datadir
    docdir
    incdir
    libdir
    mandir
    prefix
    shlibdir
"

CMDLINE_SET="
    $PATHS_LIST
    ar
    arch
    as
    assert_level
    build_suffix
    cc
    cpu
    cross_prefix
    cxx
    dep_cc
    extra_version
    host_cc
    host_cflags
    host_ld
    host_ldflags
    host_libs
    host_os
    install
    ld
    logfile
    malloc_prefix
    nm
    optflags
    pkg_config
    pkg_config_flags
    progs_suffix
    random_seed
    samples
    strip
    sysinclude
    sysroot
    target_exec
    target_os
    target_path
    target_samples
    tempprefix
    toolchain
    valgrind
    yasmexe
"

CMDLINE_APPEND="
    extra_cflags
    extra_cxxflags
    host_cppflags
"

# code dependency declarations

# architecture extensions

armv5te_deps="arm"
armv6_deps="arm"
armv6t2_deps="arm"
neon_deps_any="aarch64 arm"
vfp_deps_any="aarch64 arm"
vfpv3_deps="vfp"

map 'eval ${v}_inline_deps=inline_asm' $ARCH_EXT_LIST_ARM

mipsfpu_deps="mips"
mips32r2_deps="mips"
mipsdspr1_deps="mips"
mipsdspr2_deps="mips"

altivec_deps="ppc"
ppc4xx_deps="ppc"

cpunop_deps="i686"
x86_64_select="i686"
x86_64_suggest="fast_cmov"

amd3dnow_deps="mmx"
amd3dnowext_deps="amd3dnow"
i686_deps="x86"
mmx_deps="x86"
mmxext_deps="mmx"
sse_deps="mmxext"
sse2_deps="sse"
sse3_deps="sse2"
ssse3_deps="sse3"
sse4_deps="ssse3"
sse42_deps="sse4"
avx_deps="sse42"
xop_deps="avx"
fma3_deps="avx"
fma4_deps="avx"
avx2_deps="avx"

mmx_external_deps="yasm"
mmx_inline_deps="inline_asm"
mmx_suggest="mmx_external mmx_inline"

for ext in $(filter_out mmx $ARCH_EXT_LIST_X86_SIMD); do
    eval dep=\$${ext}_deps
    eval ${ext}_external_deps='"${dep}_external"'
    eval ${ext}_inline_deps='"${dep}_inline"'
    eval ${ext}_suggest='"${ext}_external ${ext}_inline"'
done

aligned_stack_if_any="aarch64 ppc x86"
fast_64bit_if_any="aarch64 alpha ia64 mips64 parisc64 ppc64 sparc64 x86_64"
fast_clz_if_any="aarch64 alpha avr32 mips ppc x86"
fast_unaligned_if_any="aarch64 ppc x86"

need_memalign="altivec neon sse"

# system capabilities
log2_deps="!libc_msvcrt"

symver_if_any="symver_asm_label symver_gnu_asm"

# threading support
atomics_gcc_if="sync_val_compare_and_swap"
atomics_suncc_if="atomic_cas_ptr machine_rw_barrier"
atomics_win32_if="MemoryBarrier"
atomics_native_if_any="$ATOMICS_LIST"
w32threads_deps="atomics_native"
threads_if_any="$THREADS_LIST"

# subsystems
dct_select="rdft"
error_resilience_select="dsputil"
frame_thread_encoder_deps="encoders threads"
mdct_select="fft"
rdft_select="fft"
mpegaudio_select="mpegaudiodsp"
mpegaudiodsp_select="dct"
mpegvideo_select="dsputil h264chroma hpeldsp videodsp"
mpegvideoenc_select="dsputil mpegvideo"

# decoders / encoders
aac_decoder_select="mdct sinewin"
aac_encoder_select="audio_frame_queue mdct sinewin"
aac_latm_decoder_select="aac_decoder aac_latm_parser"
ac3_decoder_select="mdct ac3dsp ac3_parser dsputil"
ac3_encoder_select="mdct ac3dsp dsputil"
ac3_fixed_encoder_select="mdct ac3dsp dsputil"
aic_decoder_select="dsputil golomb"
alac_encoder_select="lpc"
als_decoder_select="dsputil"
amrnb_decoder_select="lsp"
amrwb_decoder_select="lsp"
amv_decoder_select="sp5x_decoder exif"
amv_encoder_select="aandcttables"
ape_decoder_select="dsputil"
asv1_decoder_select="dsputil"
asv1_encoder_select="dsputil"
asv2_decoder_select="dsputil"
asv2_encoder_select="dsputil"
atrac1_decoder_select="mdct sinewin"
atrac3_decoder_select="mdct"
atrac3p_decoder_select="mdct sinewin"
avrn_decoder_select="exif"
bink_decoder_select="dsputil hpeldsp"
binkaudio_dct_decoder_select="mdct rdft dct sinewin"
binkaudio_rdft_decoder_select="mdct rdft sinewin"
cavs_decoder_select="dsputil golomb h264chroma videodsp"
cllc_decoder_select="dsputil"
comfortnoise_encoder_select="lpc"
cook_decoder_select="dsputil mdct sinewin"
cscd_decoder_select="lzo"
cscd_decoder_suggest="zlib"
dca_decoder_select="mdct"
dirac_decoder_select="dsputil dwt golomb videodsp"
dnxhd_decoder_select="dsputil"
dnxhd_encoder_select="aandcttables dsputil mpegvideoenc"
dvvideo_decoder_select="dsputil"
dvvideo_encoder_select="dsputil"
dxa_decoder_select="zlib"
eac3_decoder_select="ac3_decoder"
eac3_encoder_select="ac3_encoder"
eamad_decoder_select="aandcttables dsputil mpegvideo"
eatgq_decoder_select="aandcttables"
eatqi_decoder_select="aandcttables dsputil error_resilience mpegvideo"
exr_decoder_select="zlib"
ffv1_decoder_select="golomb rangecoder"
ffv1_encoder_select="rangecoder"
ffvhuff_decoder_select="huffyuv_decoder"
ffvhuff_encoder_select="huffyuv_encoder"
fic_decoder_select="dsputil golomb"
flac_decoder_select="golomb"
flac_encoder_select="dsputil golomb lpc"
flashsv_decoder_select="zlib"
flashsv_encoder_select="zlib"
flashsv2_encoder_select="zlib"