configure

    test_cpp "$@" <<EOF
#include <$header>
#if !($condition)
#error "unsatisfied condition: $condition"
#endif
EOF
}

check_cpp_condition(){
    log check_cpp_condition "$@"
    name=$1
    shift 1
    disable $name
    test_cpp_condition "$@" && enable $name
}

test_cflags_cpp(){
    log test_cflags_cpp "$@"
    flags=$1
    condition=$2
    shift 2
    set -- $($cflags_filter "$flags")
    test_cpp "$@" <<EOF
#if !($condition)
#error "unsatisfied condition: $condition"
#endif
EOF
}

check_lib(){
    log check_lib "$@"
    name="$1"
    headers="$2"
    funcs="$3"
    shift 3
    disable $name
    check_func_headers "$headers" "$funcs" "$@" &&
        enable $name && eval ${name}_extralibs="\$@"
}

test_pkg_config(){
    log test_pkg_config "$@"
    name="$1"
    pkg_version="$2"
    pkg="${2%% *}"
    headers="$3"
    funcs="$4"
    shift 4
    disable $name
    test_cmd $pkg_config --exists --print-errors $pkg_version || return
    pkg_cflags=$($pkg_config --cflags $pkg_config_flags $pkg)
    pkg_libs=$($pkg_config --libs $pkg_config_flags $pkg)
    check_func_headers "$headers" "$funcs" $pkg_cflags $pkg_libs "$@" &&
        enable $name &&
        set_sanitized "${name}_cflags"    $pkg_cflags &&
        set_sanitized "${name}_extralibs" $pkg_libs
}

check_pkg_config(){
    log check_pkg_config "$@"
    name="$1"
    test_pkg_config "$@" &&
        eval add_cflags \$${name}_cflags
}

test_exec(){
    log test_exec "$@"
    test_ld "$@" && { enabled cross_compile || $TMPE >> $logfile 2>&1; }
}

check_exec_crash(){
    log 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.

    (test_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=$2
    shift 2
    disable_sanitized "$type"
    test_code cc "$headers" "$type v" "$@" && enable_sanitized "$type"
}

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

check_builtin(){
    log check_builtin "$@"
    name=$1
    shift
    disable "$name"
    test_code ld "$@" && enable "$name"
}

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

check_cc(){
    log check_cc "$@"
    name=$1
    shift
    disable "$name"
    test_code cc "$@" && enable "$name"
}

require(){
    log require "$@"
    name_version="$1"
    name="${1%% *}"
    shift
    check_lib $name "$@" || die "ERROR: $name_version not found"
}

require_cc(){
    log require_cc "$@"
    name="$1"
    shift
    test_code cc "$@" || die "ERROR: $name failed"
}

require_header(){
    log require_header "$@"
    headers="$1"
    check_header "$@" || die "ERROR: $headers not found"
}

require_cpp_condition(){
    log require_cpp_condition "$@"
    condition="$2"
    test_cpp_condition "$@" || die "ERROR: $condition not satisfied"
}

require_pkg_config(){
    log require_pkg_config "$@"
    pkg_version="$2"
    check_pkg_config "$@" || die "ERROR: $pkg_version not found"
}

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

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

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

test_host_cpp(){
    log test_host_cpp "$@"
    cat > $TMPC
    log_file $TMPC
    test_cmd $host_cc $host_cppflags $host_cflags "$@" $(hostcc_e $TMPO) $TMPC
}

check_host_cppflags(){
    log check_host_cppflags "$@"
    test_host_cpp "$@" <<EOF && append host_cppflags "$@"
#include <stdlib.h>;
EOF
}

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

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

check_host_cpp_condition(){
    log check_host_cpp_condition "$@"
    name=$1
    shift 1
    disable $name
    test_host_cpp_condition "$@" && enable $name
}

cp_if_changed(){
    cmp -s "$1" "$2" && { test "$quiet" != "yes" && 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.

AVCODEC_COMPONENTS="
    bsfs
    decoders
    encoders
    hwaccels
    parsers
"

AVDEVICE_COMPONENTS="
    indevs
"
AVFILTER_COMPONENTS="
    filters
"
AVFORMAT_COMPONENTS="
    demuxers
    muxers
    protocols
"

COMPONENT_LIST="
    $AVCODEC_COMPONENTS
    $AVDEVICE_COMPONENTS
    $AVFILTER_COMPONENTS
    $AVFORMAT_COMPONENTS
"

EXAMPLE_LIST="
    decode_audio_example
    decode_video_example
    encode_audio_example
    encode_video_example
    filter_audio_example
    metadata_example
    output_example
    qsvdec_example
    transcode_aac_example
"

# catchall list of things that require external libs to link
EXTRALIBS_LIST="
    cpu_init
    cws2fws
"

HWACCEL_LIBRARY_NONFREE_LIST="
    cuda
    cuvid
    libnpp
"
HWACCEL_LIBRARY_LIST="
    $HWACCEL_LIBRARY_NONFREE_LIST
    amf
    d3d11va
    dxva2
    libmfx
    mmal
    nvenc
    omx
    vaapi
    vda
    vdpau
"

EXTERNAL_LIBRARY_GPL_LIST="
    libcdio
    libx264
    libx265
    libxavs
    libxvid
"

EXTERNAL_LIBRARY_NONFREE_LIST="
    libfaac
    libfdk_aac
    openssl
"

EXTERNAL_LIBRARY_VERSION3_LIST="
    libopencore_amrnb
    libopencore_amrwb
    libvo_aacenc
    libvo_amrwbenc
"

EXTERNAL_LIBRARY_LIST="
    $EXTERNAL_LIBRARY_GPL_LIST
    $EXTERNAL_LIBRARY_NONFREE_LIST
    $EXTERNAL_LIBRARY_VERSION3_LIST
    avisynth
    avxsynth
    frei0r
    gnutls
    libbs2b
    libdc1394
    libdcadec
    libfontconfig
    libfreetype
    libgsm
    libhdcd
    libilbc
    libjack
    libkvazaar
    libmp3lame
    libopencv
    libopenh264
    libopenjpeg
    libopus
    libpulse
    librtmp
    libschroedinger
    libsnappy
    libspeex
    libtheora
    libtwolame
    libvorbis
    libvpx
    libwavpack
    libwebp
    libxcb
    libxcb_shm
    libxcb_xfixes
"

SYSTEM_LIBRARY_LIST="
    bzlib
    zlib
"

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

LIBRARY_LIST="
    avcodec
    avdevice
    avfilter
    avformat
    avresample
    avutil
    swscale
"

LICENSE_LIST="
    gpl
    nonfree
    version3
"

PROGRAM_LIST="
    avconv
    avplay
    avprobe
"

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

# COMPONENT_LIST needs to come last to ensure correct dependency checking
CONFIG_LIST="
    $EXAMPLE_LIST
    $EXTERNAL_LIBRARY_LIST
    $HWACCEL_LIBRARY_LIST
    $FEATURE_LIST
    $LICENSE_LIST
    $LIBRARY_LIST
    $PROGRAM_LIST
    $SUBSYSTEM_LIST
    $SYSTEM_LIBRARY_LIST
    neon_clobber_test
    pic
    pod2man
    texi2html
    thumb
    valgrind_backtrace
    xmm_clobber_test
    $COMPONENT_LIST
"

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
    power8
    ppc4xx
    vsx
"

ARCH_EXT_LIST_X86="
    $ARCH_EXT_LIST_X86_SIMD
    cpunop
    i686
"

ARCH_EXT_LIST_MIPS="
    loongson
    mips32r1
    mips64r1
    mips32r2
    mips64r2
    mips32r6
    mips64r6
"

ARCH_EXT_LIST="
    $ARCH_EXT_LIST_ARM
    $ARCH_EXT_LIST_MIPS
    $ARCH_EXT_LIST_PPC
    $ARCH_EXT_LIST_X86
    vis
"

ARCH_FEATURES="
    aligned_stack
    fast_64bit
    fast_clz
    fast_cmov
    local_aligned_8
    local_aligned_16
    local_aligned_32
    simd_align_16
    simd_align_32
"

BUILTIN_LIST="
    atomic_cas_ptr
    machine_rw_barrier
    MemoryBarrier
    mm_empty
    rdtsc
    sem_timedwait
    sync_val_compare_and_swap
"
HAVE_LIST_CMDLINE="
    inline_asm
    symver
    x86asm
"

HAVE_LIST_PUB="
    bigendian
    fast_unaligned
"

HEADERS_LIST="
    AVFoundation_AVFoundation_h
    arpa_inet_h
    cdio_paranoia_h
    cdio_paranoia_paranoia_h
    dispatch_dispatch_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
    dxgidebug_h
    dxva_h
    io_h
    machine_ioctl_bt848_h
    machine_ioctl_meteor_h
    malloc_h
    poll_h
    sys_param_h
    sys_resource_h
    sys_select_h
    sys_soundcard_h
    sys_time_h
    sys_un_h
    sys_videoio_h
    unistd_h
    valgrind_valgrind_h
    windows_h
    winsock2_h
"

INTRINSICS_LIST="
    intrinsics_neon
"

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

SYSTEM_FEATURES="
    dos_paths
    libc_msvcrt
    MMAL_PARAMETER_VIDEO_MAX_NUM_CALLBACKS
    section_data_rel_ro
    threads
    uwp
"

SYSTEM_FUNCS="
    aligned_malloc
    clock_gettime
    closesocket
    CommandLineToArgvW
    fcntl
    getaddrinfo
    gethrtime
    getopt
    GetProcessAffinityMask
    GetProcessMemoryInfo
    GetProcessTimes
    getrusage
    GetSystemTimeAsFileTime
    gettimeofday
    gmtime_r
    inet_aton
    isatty
    localtime_r
    mach_absolute_time
    MapViewOfFile
    memalign
    mmap
    mprotect
    nanosleep
    posix_memalign
    sched_getaffinity
    SetConsoleTextAttribute
    setmode
    setrlimit
    Sleep
    strerror_r
    sysconf
    sysctl
    usleep
    VirtualAlloc
"

SYSTEM_LIBRARIES="
    sdl
    vaapi_1
    vaapi_drm
    vaapi_x11
    vdpau_x11
    wincrypt
"

TOOLCHAIN_FEATURES="
    as_arch_directive
    as_fpu_directive
    as_func
    as_object_arch
    asm_mod_q
    blocks_extension
    ebp_available
    ebx_available
    gnu_as
    ibm_asm
    inline_asm_labels
    pragma_deprecated
    symver_asm_label
    symver_gnu_asm
    vfp_args
    xform_asm
    xmm_clobbers
"

TYPES_LIST="
    CONDITION_VARIABLE_Ptr
    CUVIDDECODECREATEINFO_bitDepthMinus8
    socklen_t
    struct_addrinfo
    struct_group_source_req
    struct_ip_mreq_source
    struct_ipv6_mreq
    struct_pollfd
    struct_rusage_ru_maxrss
    struct_sockaddr_in6
    struct_sockaddr_sa_len
    struct_sockaddr_storage
    struct_v4l2_frmivalenum_discrete
"

HAVE_LIST="
    $ARCH_EXT_LIST
    $(add_suffix _external $ARCH_EXT_LIST)
    $(add_suffix _inline   $ARCH_EXT_LIST)
    $ARCH_FEATURES
    $BUILTIN_LIST
    $HAVE_LIST_CMDLINE
    $HAVE_LIST_PUB
    $HEADERS_LIST
    $INTRINSICS_LIST
    $MATH_FUNCS
    $SYSTEM_FEATURES
    $SYSTEM_FUNCS
    $SYSTEM_LIBRARIES
    $THREADS_LIST
    $TOOLCHAIN_FEATURES
    $TYPES_LIST
"

# options emitted with CONFIG_ prefix but not available on the command line
CONFIG_EXTRA="
    aandcttables
    ac3dsp
    adts_header
    audio_frame_queue
    audiodsp
    blockdsp
    bswapdsp
    cabac
    cbs
    cbs_h264
    cbs_h265
    cbs_mpeg2
    dirac_parse
    dvprofile
    faandct
    faanidct
    fdctdsp
    flacdsp
    fmtconvert
    g722dsp
    gmp
    golomb
    gplv3
    h263dsp
    h264chroma
    h264dsp
    h264parse
    h264pred
    h264qpel
    hevcparse
    hpeldsp
    huffman
    huffyuvdsp
    huffyuvencdsp
    idctdsp
    iirfilter
    imdct15
    intrax8
    iso_media
    ividsp
    jpegtables
    lgplv3
    libx262
    libxcb_shape
    lpc
    lzf
    me_cmp
    mpeg_er
    mpegaudio
    mpegaudiodsp
    mpegaudioheader
    mpegvideo
    mpegvideoenc
    mss34dsp
    pixblockdsp
    qpeldsp
    qsv
    qsvdec
    qsvenc
    qsvvpp
    rangecoder
    riffdec
    riffenc
    rtpdec
    rtpenc_chain
    rv34dsp
    sinewin
    snappy
    srtp
    startcode
    texturedsp
    texturedspenc
    tpeldsp
    vaapi_encode
    vc1dsp
    videodsp
    vp3dsp
    vp56dsp
    vp8dsp
    wma_freqs
    wmv2dsp
"

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

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

CMDLINE_SET="
    $PATHS_LIST
    ar
    arch
    as
    cc
    objcc
    cpu
    cross_prefix
    custom_allocator
    dep_cc
    env
    extra_version
    host_cc
    host_cflags
    host_extralibs
    host_ld
    host_ldflags
    host_os
    ignore_tests
    ld
    logfile
    malloc_prefix
    nm
    optflags
    pkg_config
    pkg_config_flags
    samples
    sysinclude
    sysroot
    target_exec
    target_os
    target_path
    target_samples
    toolchain
    x86asmexe
"

CMDLINE_APPEND="
    extra_cflags
    extra_objcflags
    host_cppflags
"

# code dependency declarations

# architecture extensions

armv5te_deps="arm"
armv6_deps="arm"
armv6t2_deps="arm"
armv8_deps="aarch64"
neon_deps_any="aarch64 arm"
intrinsics_neon_deps="neon"
vfp_deps_any="aarch64 arm"
vfpv3_deps="vfp"

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

altivec_deps="ppc"
dcbzl_deps="ppc"
ldbrx_deps="ppc"
ppc4xx_deps="ppc"
vsx_deps="altivec"
power8_deps="vsx"

loongson_deps="mips"
mips32r1_deps="mips32"
mips32r2_deps="mips32"
mips32r6_deps="mips32"
mips64r1_deps="mips64"
mips64r2_deps="mips64"
mips64r6_deps="mips64"

vis_deps="sparc"

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="x86asm"
mmx_inline_deps="inline_asm x86"
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"
simd_align_16_if_any="altivec neon sse"
simd_align_32_if_any="avx"

# system capabilities
symver_if_any="symver_asm_label symver_gnu_asm"
valgrind_backtrace_conflict="optimizations"
valgrind_backtrace_deps="valgrind_valgrind_h"

# 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
cbs_h264_select="cbs golomb"
cbs_h265_select="cbs golomb"
cbs_mpeg2_select="cbs"
dct_select="rdft"
dirac_parse_select="golomb"
error_resilience_select="me_cmp"
faandct_deps="faan"
faandct_select="fdctdsp"
faanidct_deps="faan"
faanidct_select="idctdsp"