configure

if enabled_all ccc libc_glibc; then
    add_ldflags -Wl,-z,now  # calls to libots crash without this
fi

check_compile_assert flt_lim "float.h limits.h" "DBL_MAX == (double)DBL_MAX" ||
    add_cppflags '-I\$(SRC_PATH)/compat/float'

esc(){
    echo "$*" | sed 's/%/%25/g;s/:/%3a/g'
}

echo "config:$arch:$subarch:$cpu:$target_os:$(esc $cc_ident):$(esc $LIBAV_CONFIGURATION)" >config.fate

check_cpp_condition stdlib.h "defined(__PIC__) || defined(__pic__) || defined(PIC)" && enable_weak pic

set_default $PATHS_LIST
set_default nm

# we need to build at least one lib type
if ! enabled_any static shared; then
    cat <<EOF
At least one library type must be built.
Specify --enable-static to build the static libraries or --enable-shared to
build the shared libraries as well. To only build the shared libraries specify
--disable-static in addition to --enable-shared.
EOF
    exit 1;
fi

die_license_disabled() {
    enabled $1 || { enabled $2 && die "$2 is $1 and --enable-$1 is not specified."; }
}

die_license_disabled gpl libcdio
die_license_disabled gpl libx264
die_license_disabled gpl libx265
die_license_disabled gpl libxavs
die_license_disabled gpl libxvid
die_license_disabled gpl x11grab

die_license_disabled nonfree cuda
die_license_disabled nonfree libfaac
die_license_disabled nonfree libfdk_aac
die_license_disabled nonfree libnpp
die_license_disabled nonfree nvenc
die_license_disabled nonfree openssl

die_license_disabled version3 libopencore_amrnb
die_license_disabled version3 libopencore_amrwb
die_license_disabled version3 libvo_aacenc
die_license_disabled version3 libvo_amrwbenc

enabled version3 && { enabled gpl && enable gplv3 || enable lgplv3; }

disabled optimizations || check_cflags -fomit-frame-pointer

enable_weak_pic() {
    disabled pic && return
    enable pic
    add_cppflags -DPIC
    case "$target_os" in
    mingw*|cygwin*)
        ;;
    *)
        add_cflags -fPIC
        ;;
    esac
    add_asflags  -fPIC
}

enabled pic && enable_weak_pic

check_cc <<EOF || die "Symbol mangling check failed."
int ff_extern;
EOF
sym=$($nm $TMPO | awk '/ff_extern/{ print substr($0, match($0, /[^ \t]*ff_extern/)) }')
extern_prefix=${sym%%ff_extern*}

check_cc <<EOF && enable_weak inline_asm
void foo(void) { __asm__ volatile ("" ::); }
EOF

_restrict=
for restrict_keyword in restrict __restrict__ __restrict; do
    check_cc <<EOF && _restrict=$restrict_keyword && break
void foo(char * $restrict_keyword p);
EOF
done

check_cc <<EOF && enable pragma_deprecated
void foo(void) { _Pragma("GCC diagnostic ignored \"-Wdeprecated-declarations\"") }
EOF

check_cc <<EOF && enable attribute_packed
struct { int x; } __attribute__((packed)) x;
EOF

check_cc <<EOF && enable attribute_may_alias
union { int x; } __attribute__((may_alias)) x;
EOF

check_cc <<EOF || die "endian test failed"
unsigned int endian = 'B' << 24 | 'I' << 16 | 'G' << 8 | 'E';
EOF
od -t x1 $TMPO | grep -q '42 *49 *47 *45' && enable bigendian

check_gas() {
    log "check_gas using '$as' as AS"
    # :vararg is used on aarch64, arm and ppc altivec
    check_as <<EOF || return 1
.macro m n, y:vararg=0
\n: .int \y
.endm
m x
EOF
    # .altmacro is only used in arm asm
    ! enabled arm || check_as <<EOF || return 1
.altmacro
EOF
    enable gnu_as
    return 0
}

if enabled_any arm aarch64 || enabled_all ppc altivec && enabled asm; then
    nogas=:
    enabled_any arm aarch64 && nogas=die
    enabled_all ppc altivec && nogas=warn
    as_noop=-v

    case $as_type in
        arm*) gaspp_as_type=armasm; as_noop=-h ;;
        gcc)  gaspp_as_type=gas ;;
        *)    gaspp_as_type=$as_type ;;
    esac

    [ $target_os = "darwin" ] && gaspp_as_type="apple-$gaspp_as_type"

    check_cmd gas-preprocessor.pl -arch $arch -as-type $gaspp_as_type -- $as $as_noop &&
        gas="gas-preprocessor.pl -arch $arch -as-type $gaspp_as_type -- $as"

    if ! check_gas ; then
        as=${gas:=$as}
        check_gas || \
            $nogas "GNU assembler not found, install/update gas-preprocessor"
    fi

    check_as <<EOF && enable as_func
.func test
.endfunc
EOF
fi

check_inline_asm inline_asm_labels '"1:\n"'

if enabled aarch64; then
    enabled armv8 && check_insn armv8 'prfm   pldl1strm, [x0]'
    # internal assembler in clang 3.3 does not support this instruction
    enabled neon && check_insn neon 'ext   v0.8B, v0.8B, v1.8B, #1'
    enabled vfp  && check_insn vfp  'fmadd d0,    d0,    d1,    d2'

    map 'enabled_any ${v}_external ${v}_inline || disable $v' $ARCH_EXT_LIST_ARM

elif enabled alpha; then

    check_cflags -mieee

elif enabled arm; then

    enabled msvc && check_cpp_condition stddef.h "defined _M_ARMT" && enable thumb
    check_cpp_condition stddef.h "defined __thumb__" && enable_weak thumb
    enabled thumb && check_cflags -mthumb || check_cflags -marm

    if     check_cpp_condition stddef.h "defined __ARM_PCS_VFP"; then
        enable vfp_args
    elif check_cpp_condition stddef.h "defined _M_ARM_FP && _M_ARM_FP >= 30"; then
        enable vfp_args
    elif ! check_cpp_condition stddef.h "defined __ARM_PCS || defined __SOFTFP__" && [ $target_os != darwin ]; then
        case "${cross_prefix:-$cc}" in
            *hardfloat*)         enable vfp_args;   fpabi=vfp ;;
            *) check_ld <<EOF && enable vfp_args && fpabi=vfp || fpabi=soft ;;
__asm__ (".eabi_attribute 28, 1");
int main(void) { return 0; }
EOF
        esac
        warn "Compiler does not indicate floating-point ABI, guessing $fpabi."
    fi

    enabled armv5te && check_insn armv5te 'qadd r0, r0, r0'
    enabled armv6   && check_insn armv6   'sadd16 r0, r0, r0'
    enabled armv6t2 && check_insn armv6t2 'movt r0, #0'
    enabled neon    && check_insn neon    'vadd.i16 q0, q0, q0'
    enabled vfp     && check_insn vfp     'fadds s0, s0, s0'
    enabled vfpv3   && check_insn vfpv3   'vmov.f32 s0, #1.0'

    [ $target_os = linux ] || [ $target_os = android ] ||
        map 'enabled_any ${v}_external ${v}_inline || disable $v' \
            $ARCH_EXT_LIST_ARM

    check_inline_asm asm_mod_q '"add r0, %Q0, %R0" :: "r"((long long)0)'

    check_as <<EOF && enable as_dn_directive
ra .dn d0.i16
.unreq ra
EOF

    # llvm's integrated assembler supports .object_arch from llvm 3.5
    [ "$objformat" = elf ] && check_as <<EOF && enable as_object_arch
.object_arch armv4
EOF

    [ $target_os != win32 ] && enabled_all armv6t2 shared !pic && enable_weak_pic

elif enabled mips; then

    check_inline_asm loongson '"dmult.g $1, $2, $3"'

    # make sure that only an instruction set is enabled
    disable mips64r6 mips32r6 mips64r2 mips32r2 mips64r1 mips32r1

    if enabled mips64; then
        check_inline_asm mips64r6 '"dlsa $0, $0, $0, 1"' ||
            check_inline_asm mips64r2 '"dext $0, $0, 0, 1"' ||
                check_inline_asm mips64r1 '"daddi $0, $0, 0"'
    else
        check_inline_asm mips32r6 '"aui $0, $0, 0"' ||
            check_inline_asm mips32r2 '"ext $0, $0, 0, 1"' ||
                check_inline_asm mips32r1 '"addi $0, $0, 0"'
    fi

elif enabled parisc; then

    if enabled gcc; then
        case $($cc -dumpversion) in
            4.[3-8].*) check_cflags -fno-optimize-sibling-calls ;;
        esac
    fi

elif enabled ppc; then

    enable local_aligned_8 local_aligned_16

    check_inline_asm dcbzl     '"dcbzl 0, %0" :: "r"(0)'
    check_inline_asm ibm_asm   '"add 0, 0, 0"'
    check_inline_asm ppc4xx    '"maclhw r10, r11, r12"'
    check_inline_asm xform_asm '"lwzx %1, %y0" :: "Z"(*(int*)0), "r"(0)'

    # AltiVec flags: The FSF version of GCC differs from the Apple version
    if enabled altivec; then
        check_cflags -maltivec -mabi=altivec &&
        { check_header altivec.h && inc_altivec_h="#include <altivec.h>" ; } ||
        check_cflags -faltivec

        # check if our compiler supports Motorola AltiVec C API
        check_cc <<EOF || disable altivec
$inc_altivec_h
int main(void) {
    vector signed int v1 = (vector signed int) { 0 };
    vector signed int v2 = (vector signed int) { 1 };
    v1 = vec_add(v1, v2);
    return 0;
}
EOF

        enabled altivec || warn "Altivec disabled, possibly missing --cpu flag"
    fi

    if enabled vsx; then
        check_cflags -mvsx &&
        check_builtin vec_vsx_ld "altivec.h" "__builtin_vec_vsx_ld" || disable vsx
    fi

    if enabled power8; then
        check_cpp_condition "altivec.h" "defined(_ARCH_PWR8)" || disable power8
    fi

elif enabled x86; then

    check_builtin rdtsc    intrin.h   "__rdtsc()"
    check_builtin mm_empty mmintrin.h "_mm_empty()"

    enable local_aligned_8 local_aligned_16

    # check whether EBP is available on x86
    # As 'i' is stored on the stack, this program will crash
    # if the base pointer is used to access it because the
    # base pointer is cleared in the inline assembly code.
    check_exec_crash <<EOF && enable ebp_available
volatile int i=0;
__asm__ volatile ("xorl %%ebp, %%ebp" ::: "%ebp");
return i;
EOF

    # check whether EBX is available on x86
    check_inline_asm ebx_available '""::"b"(0)' &&
        check_inline_asm ebx_available '"":::"%ebx"'

    # check whether xmm clobbers are supported
    check_inline_asm xmm_clobbers '"":::"%xmm0"'

    # check whether binutils is new enough to compile SSSE3/MMXEXT
    enabled ssse3  && check_inline_asm ssse3_inline  '"pabsw %xmm0, %xmm0"'
    enabled mmxext && check_inline_asm mmxext_inline '"pmaxub %mm0, %mm1"'

    if ! disabled_any asm mmx yasm; then
        if check_cmd $yasmexe --version; then
            enabled x86_64 && yasm_extra="-m amd64"
            yasm_debug="-g dwarf2"
        elif check_cmd nasm -v; then
            yasmexe=nasm
            yasm_debug="-g -F dwarf"
            enabled x86_64 && test "$objformat" = elf && objformat=elf64
        fi

        YASMFLAGS="-f $objformat $yasm_extra"
        enabled pic               && append YASMFLAGS "-DPIC"
        test -n "$extern_prefix"  && append YASMFLAGS "-DPREFIX"
        case "$objformat" in
            elf*) enabled debug && append YASMFLAGS $yasm_debug ;;
        esac

        check_yasm "movbe ecx, [5]" && enable yasm ||
            die "yasm/nasm not found or too old. Use --disable-yasm for a crippled build."
        check_yasm "vextracti128 xmm0, ymm0, 0"      || disable avx2_external
        check_yasm "vpmacsdd xmm0, xmm1, xmm2, xmm3" || disable xop_external
        check_yasm "vfmadd132ps ymm0, ymm1, ymm2"    || disable fma3_external
        check_yasm "vfmaddps ymm0, ymm1, ymm2, ymm3" || disable fma4_external
        check_yasm "CPU amdnop" || disable cpunop
    fi

    case "$cpu" in
        athlon*|opteron*|k8*|pentium|pentium-mmx|prescott|nocona|atom|geode)
            disable fast_clz
        ;;
    esac

fi

check_code cc arm_neon.h "int16x8_t test = vdupq_n_s16(0)" && enable intrinsics_neon

check_ldflags -Wl,--as-needed

if check_func dlopen; then
    ldl=
elif check_func dlopen -ldl; then
    ldl=-ldl
fi

if ! disabled network; then
    check_func getaddrinfo $network_extralibs
    check_func inet_aton $network_extralibs

    check_type netdb.h "struct addrinfo"
    check_type netinet/in.h "struct group_source_req" -D_BSD_SOURCE
    check_type netinet/in.h "struct ip_mreq_source" -D_BSD_SOURCE
    check_type netinet/in.h "struct ipv6_mreq" -D_DARWIN_C_SOURCE
    check_type poll.h "struct pollfd"
    check_type netinet/sctp.h "struct sctp_event_subscribe"
    check_struct "sys/types.h sys/socket.h" "struct sockaddr" sa_len
    check_type netinet/in.h "struct sockaddr_in6"
    check_type "sys/types.h sys/socket.h" "struct sockaddr_storage"
    check_type "sys/types.h sys/socket.h" socklen_t

    # Prefer arpa/inet.h over winsock2
    if check_header arpa/inet.h ; then
        check_func closesocket
    elif check_header winsock2.h ; then
        check_func_headers winsock2.h closesocket -lws2 &&
            network_extralibs="-lws2" ||
        { check_func_headers winsock2.h closesocket -lws2_32 &&
            network_extralibs="-lws2_32"; } || disable winsock2_h network
        check_func_headers ws2tcpip.h getaddrinfo $network_extralibs

        check_type ws2tcpip.h socklen_t
        check_type ws2tcpip.h "struct addrinfo"
        check_type ws2tcpip.h "struct group_source_req"
        check_type ws2tcpip.h "struct ip_mreq_source"
        check_type ws2tcpip.h "struct ipv6_mreq"
        check_type winsock2.h "struct pollfd"
        check_struct winsock2.h "struct sockaddr" sa_len
        check_type ws2tcpip.h "struct sockaddr_in6"
        check_type ws2tcpip.h "struct sockaddr_storage"
    else
        disable network
    fi
fi

check_builtin atomic_cas_ptr atomic.h "void **ptr; void *oldval, *newval; atomic_cas_ptr(ptr, oldval, newval)"
check_builtin machine_rw_barrier mbarrier.h "__machine_rw_barrier()"
check_builtin MemoryBarrier windows.h "MemoryBarrier()"
check_builtin sync_val_compare_and_swap "" "int *ptr; int oldval, newval; __sync_val_compare_and_swap(ptr, oldval, newval)"

case "$custom_allocator" in
    jemalloc)
        # jemalloc by default does not use a prefix
        require libjemalloc jemalloc/jemalloc.h malloc -ljemalloc
    ;;
    tcmalloc)
        require_pkg_config libtcmalloc gperftools/tcmalloc.h tc_malloc
        malloc_prefix=tc_
    ;;
esac

check_func_headers malloc.h _aligned_malloc     && enable aligned_malloc
check_func  ${malloc_prefix}memalign            && enable memalign
check_func  ${malloc_prefix}posix_memalign      && enable posix_memalign

check_cpp_condition unistd.h "defined(_POSIX_MONOTONIC_CLOCK)" &&
    check_func_headers time.h clock_gettime || { check_func_headers time.h clock_gettime -lrt && add_extralibs -lrt && LIBRT="-lrt"; }

check_func  fcntl
check_func  fork
check_func  gethrtime
check_func  getopt
check_func  getrusage
check_func  gettimeofday
check_func  gmtime_r
check_func  isatty
check_func  localtime_r
check_func  mach_absolute_time
check_func  mkstemp
check_func  mmap
check_func  mprotect
# Solaris has nanosleep in -lrt, OpenSolaris no longer needs that
check_func_headers time.h nanosleep || { check_func_headers time.h nanosleep -lrt && add_extralibs -lrt; }
check_func  sched_getaffinity
check_func  setrlimit
check_func  strerror_r
check_func  sysconf
check_func  sysctl
check_func  usleep

check_func_headers io.h setmode
check_func_headers stdlib.h getenv

check_func_headers windows.h CoTaskMemFree -lole32
check_func_headers windows.h GetProcessAffinityMask
check_func_headers windows.h GetProcessTimes
check_func_headers windows.h GetSystemTimeAsFileTime
check_func_headers windows.h LoadLibrary
check_func_headers windows.h MapViewOfFile
check_func_headers windows.h SetConsoleTextAttribute
check_func_headers windows.h Sleep
check_func_headers windows.h VirtualAlloc
check_struct windows.h "CONDITION_VARIABLE" Ptr

check_header direct.h
check_header dlfcn.h
check_header d3d11.h
check_header dxva.h
check_header dxva2api.h
check_header io.h
check_header mach/mach_time.h
check_header malloc.h
check_header poll.h
check_header sys/mman.h
check_header sys/param.h
check_header sys/resource.h
check_header sys/select.h
check_header sys/time.h
check_header sys/un.h
check_header unistd.h
check_header valgrind/valgrind.h
check_header vdpau/vdpau.h
check_header vdpau/vdpau_x11.h
check_header VideoDecodeAcceleration/VDADecoder.h
check_header windows.h
check_header X11/extensions/XvMClib.h

check_lib2 "windows.h shellapi.h" CommandLineToArgvW -lshell32
check_lib2 "windows.h wincrypt.h" CryptGenRandom -ladvapi32
check_lib2 "windows.h psapi.h" GetProcessMemoryInfo -lpsapi

check_struct "sys/time.h sys/resource.h" "struct rusage" ru_maxrss

check_type "windows.h dxva.h" "DXVA_PicParams_HEVC" -DWINAPI_FAMILY=WINAPI_FAMILY_DESKTOP_APP -D_CRT_BUILD_DESKTOP_APP=0
check_type "windows.h d3d11.h" "ID3D11VideoDecoder"
check_type "d3d9.h dxva2api.h" DXVA2_ConfigPictureDecode -D_WIN32_WINNT=0x0602

check_type "va/va.h va/va_vpp.h" "VAProcPipelineParameterBuffer"
check_type "va/va.h va/va_enc_h264.h" "VAEncPictureParameterBufferH264"
check_type "va/va.h va/va_enc_hevc.h" "VAEncPictureParameterBufferHEVC"
check_type "va/va.h va/va_enc_jpeg.h" "VAEncPictureParameterBufferJPEG"

check_type "vdpau/vdpau.h" "VdpPictureInfoHEVC"

if ! disabled w32threads && ! enabled pthreads; then
    check_func_headers "windows.h process.h" _beginthreadex &&
        enable w32threads || disable w32threads
fi

# check for some common methods of building with pthread support
# do this before the optional library checks as some of them require pthreads
if ! disabled pthreads && ! enabled w32threads; then
    enable pthreads
    if check_func pthread_join -pthread; then
        add_cflags -pthread
        add_extralibs -pthread
    elif check_func pthread_join -pthreads; then
        add_cflags -pthreads
        add_extralibs -pthreads
    elif check_func pthread_join -lpthreadGC2; then
        add_extralibs -lpthreadGC2
    elif check_lib pthread.h pthread_join -lpthread; then
        :
    elif ! check_func pthread_join; then
        disable pthreads
    fi
fi

enabled pthreads &&
    check_builtin sem_timedwait semaphore.h "sem_t *s; sem_init(s,0,0); sem_timedwait(s,0); sem_destroy(s)"

disabled  zlib || check_lib   zlib.h      zlibVersion -lz   || disable  zlib
disabled bzlib || check_lib2 bzlib.h BZ2_bzlibVersion -lbz2 || disable bzlib

check_lib math.h sin -lm && LIBM="-lm"
enabled vaapi && require vaapi va/va.h vaInitialize -lva

atan2f_args=2
ldexpf_args=2
powf_args=2

for func in $MATH_FUNCS; do
    eval check_mathfunc $func \${${func}_args:-1}
done

# these are off by default, so fail if requested and not available
enabled avisynth          && { check_lib2 "avisynth/avisynth_c.h windows.h" LoadLibrary ||
                               check_lib2 "avxsynth/avxsynth_c.h dlfcn.h" dlopen -ldl   ||
                               die "ERROR: LoadLibrary/dlopen not found, or avisynth header not found"; }
enabled cuda              && check_lib cuda.h cuInit -lcuda
enabled frei0r            && { check_header frei0r.h || die "ERROR: frei0r.h header not found"; }
enabled gnutls            && require_pkg_config gnutls gnutls/gnutls.h gnutls_global_init
enabled libbs2b           && require_pkg_config libbs2b bs2b.h bs2b_open
enabled libdcadec         && require libdcadec libdcadec/dca_context.h dcadec_context_create -ldcadec
enabled libfaac           && require2 libfaac "stdint.h faac.h" faacEncGetVersion -lfaac
enabled libfdk_aac        && require_pkg_config fdk-aac "fdk-aac/aacenc_lib.h" aacEncOpen
enabled libfontconfig     && require_pkg_config fontconfig "fontconfig/fontconfig.h" FcInit
enabled libfreetype       && require_pkg_config freetype2 "ft2build.h FT_FREETYPE_H" FT_Init_FreeType
enabled libgsm            && { for gsm_hdr in "gsm.h" "gsm/gsm.h"; do
                                   check_lib "${gsm_hdr}" gsm_create -lgsm && break;
                               done || die "ERROR: libgsm not found"; }
enabled libilbc           && require libilbc ilbc.h WebRtcIlbcfix_InitDecode -lilbc
enabled libkvazaar        && require_pkg_config "kvazaar >= 0.8.1" kvazaar.h kvz_api_get
enabled libmfx            && require_pkg_config libmfx "mfx/mfxvideo.h" MFXInit
enabled libmp3lame        && require "libmp3lame >= 3.98.3" lame/lame.h lame_set_VBR_quality -lmp3lame
enabled libnpp            && require libnpp npp.h nppGetLibVersion -lnppi -lnppc
enabled libopencore_amrnb && require libopencore_amrnb opencore-amrnb/interf_dec.h Decoder_Interface_init -lopencore-amrnb
enabled libopencore_amrwb && require libopencore_amrwb opencore-amrwb/dec_if.h D_IF_init -lopencore-amrwb
enabled libopencv         && require_pkg_config opencv opencv/cv.h cvCreateImageHeader
enabled libopenh264       && require_pkg_config openh264 wels/codec_api.h WelsGetCodecVersion
enabled libopenjpeg       && { { check_header openjpeg.h && check_lib2 openjpeg.h opj_version -lopenjpeg -DOPJ_STATIC; } ||
                               { require_pkg_config libopenjpeg1 openjpeg.h opj_version -DOPJ_STATIC; } }
enabled libopus           && require_pkg_config opus opus_multistream.h opus_multistream_decoder_create
enabled libpulse          && require_pkg_config libpulse-simple pulse/simple.h pa_simple_new
enabled librtmp           && require_pkg_config librtmp librtmp/rtmp.h RTMP_Socket
enabled libschroedinger   && require_pkg_config schroedinger-1.0 schroedinger/schro.h schro_init
enabled libsnappy         && require snappy snappy-c.h snappy_compress -lsnappy
enabled libspeex          && require_pkg_config speex speex/speex.h speex_decoder_init -lspeex
enabled libtheora         && require libtheora theora/theoraenc.h th_info_init -ltheoraenc -ltheoradec -logg
enabled libtwolame        && require libtwolame twolame.h twolame_init -ltwolame
enabled libvo_aacenc      && require libvo_aacenc vo-aacenc/voAAC.h voGetAACEncAPI -lvo-aacenc
enabled libvo_amrwbenc    && require libvo_amrwbenc vo-amrwbenc/enc_if.h E_IF_init -lvo-amrwbenc
enabled libvorbis         && require libvorbis vorbis/vorbisenc.h vorbis_info_init -lvorbisenc -lvorbis -logg
enabled libvpx            && require_pkg_config "vpx >= 1.3.0" vpx/vpx_codec.h vpx_codec_version && {
    enabled libvpx_vp8_decoder && {
        check_pkg_config vpx "vpx/vpx_decoder.h vpx/vp8dx.h" vpx_codec_vp8_dx ||
            disable libvpx_vp8_decoder;
    }
    enabled libvpx_vp8_encoder && {
        check_pkg_config vpx "vpx/vpx_encoder.h vpx/vp8cx.h" vpx_codec_vp8_cx ||
            disable libvpx_vp8_encoder;
    }
    enabled libvpx_vp9_decoder && {
        check_pkg_config vpx "vpx/vpx_decoder.h vpx/vp8dx.h" vpx_codec_vp9_dx ||
            disable libvpx_vp9_decoder;
    }
    enabled libvpx_vp9_encoder && {
        check_pkg_config vpx "vpx/vpx_encoder.h vpx/vp8cx.h" vpx_codec_vp9_cx ||
            disable libvpx_vp9_encoder;
    }
    if disabled_all libvpx_vp8_decoder libvpx_vp9_decoder libvpx_vp8_encoder libvpx_vp9_encoder; then
        die "libvpx enabled but no supported decoders found"
    fi
}
enabled libwavpack        && require libwavpack wavpack/wavpack.h WavpackOpenFileOutput  -lwavpack
enabled libwebp           && require_pkg_config libwebp webp/encode.h WebPGetEncoderVersion
enabled libx264           && require_pkg_config x264 "stdint.h x264.h" x264_encoder_encode &&
                             { check_cpp_condition x264.h "X264_BUILD >= 118" ||
                               die "ERROR: libx264 version must be >= 0.118."; } &&
                             { check_cpp_condition x264.h "X264_MPEG2" &&
                               enable libx262; }
enabled libx265           && require_pkg_config x265 x265.h x265_api_get &&
                             { check_cpp_condition x265.h "X265_BUILD >= 57" ||
                               die "ERROR: libx265 version must be >= 57."; }
enabled libxavs           && require libxavs xavs.h xavs_encoder_encode -lxavs
enabled libxvid           && require libxvid xvid.h xvid_global -lxvidcore
enabled mmal              && { check_lib interface/mmal/mmal.h mmal_port_connect -lmmal_core -lmmal_util -lmmal_vc_client -lbcm_host ||
                                { ! enabled cross_compile && {
                                    add_cflags -isystem/opt/vc/include/ -isystem/opt/vc/include/interface/vmcs_host/linux -isystem/opt/vc/include/interface/vcos/pthreads -fgnu89-inline ;
                                    add_extralibs -L/opt/vc/lib/ -lmmal_core -lmmal_util -lmmal_vc_client -lbcm_host ;
                                    check_lib interface/mmal/mmal.h mmal_port_connect ; }
                                check_lib interface/mmal/mmal.h mmal_port_connect ; } ||
                               die "ERROR: mmal not found"; }
enabled openssl           && { check_pkg_config openssl openssl/ssl.h SSL_library_init && {
                               add_cflags $openssl_cflags && add_extralibs $openssl_libs; }||
                               check_lib openssl/ssl.h SSL_library_init -lssl -lcrypto ||
                               check_lib openssl/ssl.h SSL_library_init -lssl32 -leay32 ||
                               check_lib openssl/ssl.h SSL_library_init -lssl -lcrypto -lws2_32 -lgdi32 ||
                               die "ERROR: openssl not found"; }

if enabled gnutls; then
    { check_lib2 gmp.h mpz_export -lgmp && enable gmp; } ||
    { check_lib gcrypt.h gcry_mpi_new -lgcrypt && enable gcrypt; }
fi

# libdc1394 check
if enabled libdc1394; then
    { require_pkg_config libdc1394-2 dc1394/dc1394.h dc1394_new &&
        enable libdc1394_2; } ||
    { check_lib libdc1394/dc1394_control.h dc1394_create_handle -ldc1394_control -lraw1394 &&
        enable libdc1394_1; } ||
    die "ERROR: No version of libdc1394 found "
fi

if enabled nvenc; then
    enabled cuda || check_header cuda.h || die "ERROR: cuda.h not found.";
    check_header nvEncodeAPI.h || die "ERROR: nvEncodeAPI.h not found.";
    check_cpp_condition nvEncodeAPI.h "NVENCAPI_MAJOR_VERSION >= 5" ||
        die "ERROR: NVENC API version 4 or older is not supported";
fi

if check_pkg_config sdl SDL_events.h SDL_PollEvent; then
    check_cpp_condition SDL.h "(SDL_MAJOR_VERSION<<16 | SDL_MINOR_VERSION<<8 | SDL_PATCHLEVEL) >= 0x010201" $sdl_cflags &&
    check_cpp_condition SDL.h "(SDL_MAJOR_VERSION<<16 | SDL_MINOR_VERSION<<8 | SDL_PATCHLEVEL) < 0x010300" $sdl_cflags &&
    enable sdl
fi

pod2man --help     > /dev/null 2>&1 && enable pod2man   || disable pod2man
texi2html -version > /dev/null 2>&1 && enable texi2html || disable texi2html

check_header linux/fb.h
check_header linux/videodev2.h
check_struct linux/videodev2.h "struct v4l2_frmivalenum" discrete

check_header AVFoundation/AVFoundation.h &&
    check_objcflags -fobjc-arc &&
    add_extralibs -framework Foundation -framework AVFoundation -framework CoreVideo -framework CoreMedia ||
    disable AVFoundation_AVFoundation_h

check_header sys/videoio.h

check_func_headers "windows.h vfw.h" capCreateCaptureWindow "$vfwcap_indev_extralibs"
# check that WM_CAP_DRIVER_CONNECT is defined to the proper value
# w32api 3.12 had it defined wrong
check_cpp_condition vfw.h "WM_CAP_DRIVER_CONNECT > WM_USER" && enable vfwcap_defines

# check for ioctl_meteor.h, ioctl_bt848.h and alternatives
{ check_header dev/bktr/ioctl_meteor.h &&
  check_header dev/bktr/ioctl_bt848.h; } ||
{ check_header machine/ioctl_meteor.h &&
  check_header machine/ioctl_bt848.h; } ||
{ check_header dev/video/meteor/ioctl_meteor.h &&
  check_header dev/video/bktr/ioctl_bt848.h; } ||
check_header dev/ic/bt8xx.h

check_header sndio.h
check_header sys/soundcard.h
check_header soundcard.h

enabled_any alsa_indev alsa_outdev &&
    check_lib2 alsa/asoundlib.h snd_pcm_htimestamp -lasound

enabled jack_indev && check_lib2 jack/jack.h jack_client_open -ljack &&
    check_func jack_port_get_latency_range -ljack

enabled_any sndio_indev sndio_outdev && check_lib2 sndio.h sio_open -lsndio

if enabled libcdio; then
    check_lib2 "cdio/cdda.h cdio/paranoia.h" cdio_cddap_open -lcdio_paranoia -lcdio_cdda -lcdio ||
    check_lib2 "cdio/paranoia/cdda.h cdio/paranoia/paranoia.h" cdio_cddap_open -lcdio_paranoia -lcdio_cdda -lcdio ||
    die "ERROR: No usable libcdio/cdparanoia found"
fi

check_lib X11/Xlib.h XOpenDisplay -lX11 && enable xlib

if enabled libxcb || enabled x11grab && ! disabled libxcb; then
    check_pkg_config xcb-shape xcb/shape.h xcb_shape_rectangles || {
        enabled libxcb && die "ERROR: libxcb not found";
    } && disable x11grab && enable libxcb

    disabled libxcb_shm ||
        check_pkg_config xcb-shm xcb/shm.h xcb_shm_attach || {
            enabled libxcb_shm && die "ERROR: libxcb_shm not found";
        } && check_header sys/shm.h && enable libxcb_shm

    disabled libxcb_xfixes ||
        check_pkg_config xcb-xfixes xcb/xfixes.h xcb_xfixes_get_cursor_image || {
            enabled libxcb_xfixes && die "ERROR: libxcb_xfixes not found";
        } && enable libxcb_xfixes

    add_cflags "$xcb_event_cflags $xcb_shm_cflags $xcb_xfixes_cflags"
    add_extralibs "$xcb_event_libs $xcb_shm_libs $xcb_xfixes_libs"
fi

if enabled x11grab; then
    enabled xlib || die "ERROR: Xlib not found"
    require Xext X11/extensions/XShm.h XShmCreateImage -lXext
    require Xfixes X11/extensions/Xfixes.h XFixesGetCursorImage -lXfixes
fi

enabled vaapi &&
    check_code cc "va/va.h" "vaCreateSurfaces(0, 0, 0, 0, 0, 0, 0, 0)" ||
    disable vaapi

if enabled vaapi ; then
    enabled xlib &&
    check_lib2 "va/va.h va/va_x11.h" vaGetDisplay -lva -lva-x11 &&
    enable vaapi_x11

    check_lib2 "va/va.h va/va_drm.h" vaGetDisplayDRM -lva -lva-drm &&
    enable vaapi_drm
fi

enabled vdpau &&
    check_cpp_condition vdpau/vdpau.h "defined VDP_DECODER_PROFILE_MPEG4_PART2_ASP" ||
    disable vdpau

enabled vdpau && enabled xlib &&
    check_func_headers "vdpau/vdpau.h vdpau/vdpau_x11.h" vdp_device_create_x11 -lvdpau &&
    prepend avconv_libs $($ldflags_filter "-lvdpau") &&
    enable vdpau_x11

enabled debug && add_cflags -g"$debuglevel" && add_asflags -g"$debuglevel"

# add some useful compiler flags if supported
check_cflags -Wdeclaration-after-statement
check_cflags -Wall
check_cflags -Wdisabled-optimization
check_cflags -Wpointer-arith
check_cflags -Wredundant-decls
check_cflags -Wwrite-strings
check_cflags -Wtype-limits
check_cflags -Wundef
check_cflags -Wmissing-prototypes
check_cflags -Wstrict-prototypes
enabled extra_warnings && check_cflags -Winline
enabled extra_warnings && check_cflags -Wcast-qual

check_disable_warning(){
    warning_flag=-W${1#-Wno-}
    test_cflags $warning_flag && add_cflags $1
}

check_disable_warning -Wno-parentheses
check_disable_warning -Wno-switch
check_disable_warning -Wno-format-zero-length
check_disable_warning -Wno-pointer-sign

# add some linker flags
check_ldflags -Wl,--warn-common
check_ldflags -Wl,-rpath-link=libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil:libavresample
enabled rpath && add_ldexeflags -Wl,-rpath,$libdir
test_ldflags -Wl,-Bsymbolic && append SHFLAGS -Wl,-Bsymbolic

# add some strip flags
# -wN '..@*' is more selective than -x, but not available everywhere.
check_stripflags -wN \'..@*\' || check_stripflags -x || strip='true'

enabled neon_clobber_test &&
    check_ldflags -Wl,--wrap,avcodec_open2              \
                  -Wl,--wrap,avcodec_decode_audio4      \
                  -Wl,--wrap,avcodec_decode_video2      \
                  -Wl,--wrap,avcodec_decode_subtitle2   \
                  -Wl,--wrap,avcodec_encode_audio2      \
                  -Wl,--wrap,avcodec_encode_video2      \
                  -Wl,--wrap,avcodec_encode_subtitle    \
                  -Wl,--wrap,avresample_convert ||
    disable neon_clobber_test

enabled xmm_clobber_test &&
    check_ldflags -Wl,--wrap,avcodec_open2              \
                  -Wl,--wrap,avcodec_decode_audio4      \
                  -Wl,--wrap,avcodec_decode_video2      \
                  -Wl,--wrap,avcodec_decode_subtitle2   \
                  -Wl,--wrap,avcodec_encode_audio2      \
                  -Wl,--wrap,avcodec_encode_video2      \
                  -Wl,--wrap,avcodec_encode_subtitle    \
                  -Wl,--wrap,avresample_convert         \
                  -Wl,--wrap,sws_scale ||
    disable xmm_clobber_test

echo "X { local: *; };" > $TMPV
if test_ldflags -Wl,--version-script,$TMPV; then
    append SHFLAGS '-Wl,--version-script,\$(SUBDIR)lib\$(NAME).ver'
elif test_ldflags -Wl,-M,$TMPV; then
    append SHFLAGS '-Wl,-M,\$(SUBDIR)lib\$(NAME).ver-sol2'
fi

check_cc <<EOF && enable symver_asm_label
void ff_foo(void) __asm__ ("av_foo@VERSION");
void ff_foo(void) { ${inline_asm+__asm__($quotes);} }
EOF
    check_cc <<EOF && enable symver_gnu_asm
__asm__(".symver ff_foo,av_foo@VERSION");
void ff_foo(void) {}
EOF

if [ -z "$optflags" ]; then
    if enabled small; then
        optflags=$cflags_size
    elif enabled optimizations; then
        optflags=$cflags_speed
    else
        optflags=$cflags_noopt
    fi
fi

check_optflags(){
    check_cflags "$@"
    enabled lto && check_ldflags "$@"
}


if enabled lto; then
    test "$cc_type" != "$ld_type" && die "LTO requires same compiler and linker"
    check_cflags  -flto
    check_ldflags -flto $cpuflags
fi

check_optflags $optflags
check_optflags -fno-math-errno
check_optflags -fno-signed-zeros

if enabled icc; then
    # Just warnings, no remarks
    check_cflags -w1
    # -wd: Disable following warnings
    # 144, 167, 556: -Wno-pointer-sign
    # 1292: attribute "foo" ignored
    # 1419: external declaration in primary source file
    # 10006: ignoring unknown option -fno-signed-zeros
    # 10148: ignoring unknown option -Wno-parentheses
    # 10156: ignoring option '-W'; no argument required
    check_cflags -wd144,167,556,1292,1419,10006,10148,10156
    # 11030: Warning unknown option --as-needed
    # 10156: ignoring option '-export'; no argument required
    check_ldflags -wd10156,11030
    # icc 11.0 and 11.1 work with ebp_available, but don't pass the test
    enable ebp_available
    if enabled x86_32; then
        icc_version=$($cc -dumpversion)
        test ${icc_version%%.*} -ge 11 &&
            check_cflags -falign-stack=maintain-16-byte ||
            disable aligned_stack
    fi
elif enabled ccc; then
    # disable some annoying warnings
    add_cflags -msg_disable bitnotint
    add_cflags -msg_disable mixfuncvoid
    add_cflags -msg_disable nonstandcast
    add_cflags -msg_disable unsupieee
elif enabled gcc; then
    check_optflags -fno-tree-vectorize
    check_cflags -Werror=implicit-function-declaration
    check_cflags -Werror=missing-prototypes
    check_cflags -Werror=return-type
    check_cflags -Werror=declaration-after-statement
    check_cflags -Werror=vla
    check_cflags -Werror=format-security
    check_cflags -fdiagnostics-color=auto
    enabled extra_warnings || check_disable_warning -Wno-maybe-uninitialized
elif enabled llvm_gcc; then
    check_cflags -mllvm -stack-alignment=16
elif enabled clang; then
    check_cflags -mllvm -stack-alignment=16
    check_cflags -Qunused-arguments
    check_cflags -Werror=implicit-function-declaration
    check_cflags -Werror=missing-prototypes
    check_cflags -Werror=return-type
elif enabled cparser; then
    add_cflags -Wno-missing-variable-declarations
    add_cflags -Wno-empty-statement
elif enabled armcc; then
    add_cflags -W${armcc_opt},--diag_suppress=4343 # hardfp compat
    add_cflags -W${armcc_opt},--diag_suppress=3036 # using . as system include dir
    # 2523: use of inline assembly is deprecated
    add_cflags -W${armcc_opt},--diag_suppress=2523
    add_cflags -W${armcc_opt},--diag_suppress=1207
    add_cflags -W${armcc_opt},--diag_suppress=1293 # assignment in condition
    add_cflags -W${armcc_opt},--diag_suppress=3343 # hardfp compat
    add_cflags -W${armcc_opt},--diag_suppress=167  # pointer sign
    add_cflags -W${armcc_opt},--diag_suppress=513  # pointer sign
elif enabled tms470; then
    add_cflags -pds=824 -pds=837
    disable inline_asm
elif enabled pathscale; then
    add_cflags -fstrict-overflow -OPT:wrap_around_unsafe_opt=OFF
elif enabled_any msvc icl; then
    enabled x86_32 && disable aligned_stack
    enabled_all x86_32 debug && add_cflags -Oy-
    enabled debug && add_ldflags -debug
    enable pragma_deprecated
    if enabled icl; then
        # -Qansi-alias is basically -fstrict-aliasing, but does not work
        # (correctly) on icl 13.x.
        check_cpp_condition "windows.h" "__ICL < 1300 || __ICL >= 1400" &&
            add_cflags -Qansi-alias
        # icl will pass the inline asm tests but inline asm is currently
        # not supported (build will fail)
        disable inline_asm
    fi
    # msvcrt10 x64 incorrectly enables log2, only msvcrt12 (MSVC 2013) onwards actually has log2.
    check_cpp_condition crtversion.h "_VC_CRT_MAJOR_VERSION >= 12" || disable log2
    # The CRT headers contain __declspec(restrict) in a few places, but if redefining
    # restrict, this might break. MSVC 2010 and 2012 fail with __declspec(__restrict)
    # (as it ends up if the restrict redefine is done before including stdlib.h), while
    # MSVC 2013 and newer can handle it fine.
    # If this declspec fails, force including stdlib.h before the restrict redefinition
    # happens in config.h.
    if [ $_restrict != restrict ]; then
        check_cc <<EOF || add_cflags -FIstdlib.h
__declspec($_restrict) void* foo(int);
EOF
    fi
    check_func strtoll || add_cflags -Dstrtoll=_strtoi64
fi

for pfx in "" host_; do
    varname=${pfx%_}cc_type
    eval "type=\$$varname"
    if [ $type = "msvc" ]; then
        check_${pfx}cc <<EOF || add_${pfx}cflags -Dinline=__inline
static inline int foo(int a) { return a; }
EOF
    fi
done

case $as_type in
    clang)
        add_asflags -Qunused-arguments
    ;;
esac

case $ld_type in
    clang)
        check_ldflags -Qunused-arguments
    ;;
esac

case $target_os in
    osf1)
        enabled ccc && add_ldflags '-Wl,-expect_unresolved,*'
    ;;
    plan9)
        add_cppflags -Dmain=plan9_main
    ;;
esac

enabled asm || { arch=c; disable $ARCH_LIST $ARCH_EXT_LIST; }

check_deps $CONFIG_LIST       \
           $CONFIG_EXTRA      \
           $HAVE_LIST         \
           $ALL_COMPONENTS    \

enabled_all dxva2 CoTaskMemFree &&
    prepend avconv_libs $($ldflags_filter "-lole32") &&
    enable dxva2_lib

! enabled_any memalign posix_memalign aligned_malloc &&
    enabled simd_align_16 && enable memalign_hack

map 'enabled $v && intrinsics=${v#intrinsics_}' $INTRINSICS_LIST

for thread in $THREADS_LIST; do
    if enabled $thread; then
        test -n "$thread_type" &&
            die "ERROR: Only one thread type must be selected." ||
            thread_type="$thread"
    fi
done

enabled zlib && add_cppflags -DZLIB_CONST

# conditional library dependencies, in linking order
enabled movie_filter    && prepend avfilter_deps "avformat avcodec"
enabled resample_filter && prepend avfilter_deps "avresample"
enabled scale_filter    && prepend avfilter_deps "swscale"

enabled opus_decoder    && prepend avcodec_deps "avresample"

expand_deps(){
    lib_deps=${1}_deps
    eval "deps=\$$lib_deps"
    append $lib_deps $(map 'eval echo \$${v}_deps' $deps)
    unique $lib_deps
}