configure

    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_inline_asm inline_asm_labels '"1:\n"'

if enabled alpha; then

    check_cflags -mieee

elif enabled arm; then

    check_cpp_condition stddef.h "defined __thumb__" && check_cc <<EOF && enable_weak thumb
float func(float a, float b){ return a+b; }
EOF

    enabled thumb && check_cflags -mthumb || check_cflags -marm
    nogas=die

    if     check_cpp_condition stddef.h "defined __ARM_PCS_VFP"; then
        enable vfp_args
    elif ! check_cpp_condition stddef.h "defined __ARM_PCS || defined __SOFTFP__"; then
        case "${cross_prefix:-$cc}" in
            *hardfloat*)         enable vfp_args;   fpabi=vfp ;;
            *) check_ld "cc" <<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 ] ||
        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_inline_asm asm_mod_y '"vmul.i32 d0, d0, %y0" :: "x"(0)'

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

elif enabled mips; then

    check_inline_asm loongson '"dmult.g $1, $2, $3"'
    enabled mips32r2  && add_cflags "-mips32r2" && add_asflags "-mips32r2" &&
     check_inline_asm mips32r2  '"rotr $t0, $t1, 1"'
    enabled mipsdspr1 && add_cflags "-mdsp" && add_asflags "-mdsp" &&
     check_inline_asm mipsdspr1 '"addu.qb $t0, $t1, $t2"'
    enabled mipsdspr2 && add_cflags "-mdspr2" && add_asflags "-mdspr2" &&
     check_inline_asm mipsdspr2 '"absq_s.qb $t0, $t1"'
    enabled mipsfpu   && add_cflags "-mhard-float" && add_asflags "-mhard-float" &&
     check_inline_asm mipsfpu   '"madd.d $f0, $f2, $f4, $f6"'

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
        if ! enabled_any pic ppc64; then
            nogas=warn
        fi
        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

elif enabled sparc; then

    enabled vis && check_inline_asm vis '"pdist %f0, %f0, %f0"'

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 "vextractf128 xmm0, ymm0, 0"      || disable avx_external avresample
        check_yasm "vfmaddps ymm0, ymm1, ymm2, ymm3" || disable fma4_external
        check_yasm "CPU amdnop" && enable cpunop
    fi

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

fi

if enabled asm; then
    as=${gas:=$as}
    check_as <<EOF && enable gnu_as || \
        $nogas "GNU assembler not found, install gas-preprocessor"
.macro m n
\n: .int 0
.endm
m x
EOF
fi

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_type "sys/types.h sys/socket.h" socklen_t
    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 netinet/in.h "struct sockaddr_in6"
    check_type poll.h "struct pollfd"
    check_type "sys/types.h sys/socket.h" "struct sockaddr_storage"
    check_struct "sys/types.h sys/socket.h" "struct sockaddr" sa_len
    check_type netinet/sctp.h "struct sctp_event_subscribe"
    check_func getaddrinfo $network_extralibs
    check_func getservbyport $network_extralibs
    # 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"; }
        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_type ws2tcpip.h "struct sockaddr_in6"
        check_type ws2tcpip.h "struct sockaddr_storage"
        check_struct winsock2.h "struct sockaddr" sa_len
    else
        disable network
    fi
fi

# Solaris has nanosleep in -lrt, OpenSolaris no longer needs that
check_func nanosleep || { check_func nanosleep -lrt && add_extralibs -lrt; }

check_func  access
check_func  clock_gettime || { check_func clock_gettime -lrt && add_extralibs -lrt; }
check_func  fcntl
check_func  fork
check_func_headers stdlib.h getenv
check_func  gethrtime
check_func  getopt
check_func  getrusage
check_struct "sys/time.h sys/resource.h" "struct rusage" ru_maxrss
check_func  gettimeofday
check_func  inet_aton $network_extralibs
check_func  isatty
check_func  localtime_r
check_func  ${malloc_prefix}memalign            && enable memalign
check_func  mkstemp
check_func  mmap
check_func  mprotect
check_func  ${malloc_prefix}posix_memalign      && enable posix_memalign
check_func_headers malloc.h _aligned_malloc     && enable aligned_malloc
check_func  setrlimit
check_struct "sys/stat.h" "struct stat" st_mtim.tv_nsec -D_BSD_SOURCE
check_func  strerror_r
check_func  sched_getaffinity
check_builtin sync_val_compare_and_swap "" "int *ptr; int oldval, newval; __sync_val_compare_and_swap(ptr, oldval, newval)"
check_builtin machine_rw_barrier mbarrier.h "__machine_rw_barrier()"
check_builtin atomic_cas_ptr atomic.h "void **ptr; void *oldval, *newval; atomic_cas_ptr(ptr, oldval, newval)"
check_builtin MemoryBarrier windows.h "MemoryBarrier()"
check_builtin sarestart signal.h "SA_RESTART"
check_func  sysconf
check_func  sysctl
check_func  usleep
check_func_headers conio.h kbhit
check_func_headers windows.h PeekNamedPipe
check_func_headers io.h setmode
check_func_headers lzo/lzo1x.h lzo1x_999_compress
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_func_headers windows.h GetProcessAffinityMask
check_func_headers windows.h GetProcessTimes
check_func_headers windows.h GetSystemTimeAsFileTime
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_func_headers glob.h glob
check_func_headers "X11/Xlib.h X11/extensions/Xvlib.h" XvGetPortAttribute -lXv -lX11 -lXext

check_header cl/cl.h
check_header direct.h
check_header dlfcn.h
check_header dxva.h
check_header dxva2api.h -D_WIN32_WINNT=0x0600
check_header io.h
check_header libcrystalhd/libcrystalhd_if.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 termios.h
check_header unistd.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_header asm/types.h

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 && ! enabled os2threads; then
    enable pthreads
    if check_func pthread_join -pthread && check_func pthread_create -pthread; then
        add_cflags -pthread
        add_extralibs -pthread
    elif check_func pthread_join -pthreads && check_func pthread_create -pthreads; then
        add_cflags -pthreads
        add_extralibs -pthreads
    elif check_func pthread_join -lpthreadGC2 && check_func pthread_create -lpthreadGC2; then
        add_extralibs -lpthreadGC2
    elif check_lib pthread.h pthread_join -lpthread && check_lib pthread.h pthread_create -lpthread; then
        :
    elif ! check_func pthread_join && ! check_func pthread_create; then
        disable pthreads
    fi
fi

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

if enabled pthreads; then
  check_func pthread_cancel
fi

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"
disabled crystalhd || check_lib libcrystalhd/libcrystalhd_if.h DtsCrystalHDVersion -lcrystalhd || disable crystalhd

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 "windows.h" LoadLibrary; } ||
                               { check_lib2 "dlfcn.h" dlopen -ldl; } ||
                               die "ERROR: LoadLibrary/dlopen not found for avisynth"; }
enabled fontconfig        && require_pkg_config fontconfig "fontconfig/fontconfig.h" FcInit
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 ladspa            && { check_header ladspa.h || die "ERROR: ladspa.h header not found"; }
enabled libiec61883       && require libiec61883 libiec61883/iec61883.h iec61883_cmp_connect -lraw1394 -lavc1394 -lrom1394 -liec61883
enabled libaacplus        && require "libaacplus >= 2.0.0" aacplus.h aacplusEncOpen -laacplus
enabled libass            && require_pkg_config libass ass/ass.h ass_library_init
enabled libbluray         && require libbluray libbluray/bluray.h bd_open -lbluray
enabled libcelt           && require libcelt celt/celt.h celt_decode -lcelt0 &&
                             { check_lib celt/celt.h celt_decoder_create_custom -lcelt0 ||
                               die "ERROR: libcelt must be installed and version must be >= 0.11.0."; }
enabled libcaca           && require_pkg_config caca caca.h caca_create_canvas
enabled libfaac           && require2 libfaac "stdint.h faac.h" faacEncGetVersion -lfaac
enabled libfdk_aac        && require libfdk_aac fdk-aac/aacenc_lib.h aacEncOpen -lfdk-aac
flite_libs="-lflite_cmu_time_awb -lflite_cmu_us_awb -lflite_cmu_us_kal -lflite_cmu_us_kal16 -lflite_cmu_us_rms -lflite_cmu_us_slt -lflite_usenglish -lflite_cmulex -lflite"
enabled libflite          && require2 libflite "flite/flite.h" flite_init $flite_libs
enabled libfreetype       && require_libfreetype
enabled libgme            && require  libgme gme/gme.h gme_new_emu -lgme -lstdc++
enabled libgsm            && { for gsm_hdr in "gsm.h" "gsm/gsm.h"; do
                                   check_lib "${gsm_hdr}" gsm_create -lgsm && break;
                               done || die "ERROR: libgsm not found"; }
enabled libilbc           && require libilbc ilbc.h WebRtcIlbcfix_InitDecode -lilbc
enabled libmodplug        && require libmodplug libmodplug/modplug.h ModPlug_Load -lmodplug
enabled libmp3lame        && require "libmp3lame >= 3.98.3" lame/lame.h lame_set_VBR_quality -lmp3lame
enabled libnut            && require libnut libnut.h nut_demuxer_init -lnut
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/cxcore.h cvCreateImageHeader
enabled libopenjpeg       && { check_lib openjpeg-1.5/openjpeg.h opj_version -lopenjpeg ||
                               check_lib openjpeg.h opj_version -lopenjpeg ||
                               die "ERROR: libopenjpeg not found"; }
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 libquvi           && require_pkg_config libquvi quvi/quvi.h quvi_init
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 libshine          && require_pkg_config shine shine/layer3.h shine_encode_buffer
enabled libsoxr           && require libsoxr soxr.h soxr_create -lsoxr
enabled libssh            && require_pkg_config libssh libssh/sftp.h sftp_init
enabled libspeex          && require libspeex speex/speex.h speex_decoder_init -lspeex
enabled libstagefright_h264 && require_cpp libstagefright_h264 "binder/ProcessState.h media/stagefright/MetaData.h
    media/stagefright/MediaBufferGroup.h media/stagefright/MediaDebug.h media/stagefright/MediaDefs.h
    media/stagefright/OMXClient.h media/stagefright/OMXCodec.h" android::OMXClient -lstagefright -lmedia -lutils -lbinder -lgnustl_static
enabled libtheora         && require libtheora theora/theoraenc.h th_info_init -ltheoraenc -ltheoradec -logg
enabled libtwolame        && require libtwolame twolame.h twolame_init -ltwolame &&
                             { check_lib twolame.h twolame_encode_buffer_float32_interleaved -ltwolame ||
                               die "ERROR: libtwolame must be installed and version must be >= 0.3.10"; }
enabled libutvideo        && require_cpp utvideo "stdint.h stdlib.h utvideo/utvideo.h utvideo/Codec.h" 'CCodec*' -lutvideo -lstdc++
enabled libv4l2           && require_pkg_config libv4l2 libv4l2.h v4l2_ioctl
enabled libvidstab        && require_pkg_config vidstab vid.stab/libvidstab.h vsMotionDetectInit
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            && {
    enabled libvpx_vp8_decoder && { check_lib2 "vpx/vpx_decoder.h vpx/vp8dx.h" vpx_codec_dec_init_ver -lvpx ||
                                    die "ERROR: libvpx decoder version must be >=0.9.1"; }
    enabled libvpx_vp8_encoder && { check_lib2 "vpx/vpx_encoder.h vpx/vp8cx.h" "vpx_codec_enc_init_ver VP8E_SET_MAX_INTRA_BITRATE_PCT" -lvpx ||
                                    die "ERROR: libvpx encoder version must be >=0.9.7"; }
    enabled libvpx_vp9_decoder && { check_lib2 "vpx/vpx_decoder.h vpx/vp8dx.h" "vpx_codec_vp9_dx" -lvpx || disable libvpx_vp9_decoder; }
    enabled libvpx_vp9_encoder && { check_lib2 "vpx/vpx_encoder.h vpx/vp8cx.h" "vpx_codec_vp9_cx VP9E_SET_SVC" -lvpx || disable libvpx_vp9_encoder; } }
enabled libwavpack        && require libwavpack wavpack/wavpack.h WavpackOpenFileOutput  -lwavpack
enabled libwebp           && require_pkg_config libwebp webp/encode.h WebPGetEncoderVersion
enabled libx264           && require libx264 x264.h x264_encoder_encode -lx264 &&
                             { check_cpp_condition x264.h "X264_BUILD >= 118" ||
                               die "ERROR: libx264 must be installed and version must be >= 0.118."; }
enabled libxavs           && require libxavs xavs.h xavs_encoder_encode -lxavs
enabled libxvid           && require libxvid xvid.h xvid_global -lxvidcore
enabled libzmq            && require_pkg_config libzmq zmq.h zmq_ctx_new
enabled libzvbi           && require libzvbi libzvbi.h vbi_decoder_new -lzvbi
enabled openal            && { { for al_libs in "${OPENAL_LIBS}" "-lopenal" "-lOpenAL32"; do
                               check_lib 'AL/al.h' alGetError "${al_libs}" && break; done } ||
                               die "ERROR: openal not found"; } &&
                             { check_cpp_condition "AL/al.h" "defined(AL_VERSION_1_1)" ||
                               die "ERROR: openal must be installed and version must be 1.1 or compatible"; }
enabled opencl            && { check_lib2 OpenCL/cl.h clEnqueueNDRangeKernel -Wl,-framework,OpenCL ||
                               check_lib2 CL/cl.h clEnqueueNDRangeKernel -lOpenCL ||
                               die "ERROR: opencl not found"; } &&
                             { ! enabled_any w32threads os2threads ||
                               die "opencl currently needs --enable-pthreads or --disable-w32threads"; } &&
                             { check_cpp_condition "OpenCL/cl.h" "defined(CL_VERSION_1_2)" ||
                               check_cpp_condition "CL/cl.h" "defined(CL_VERSION_1_2)" ||
                               die "ERROR: opencl must be installed and version must be 1.2 or compatible"; }
enabled openssl           && { 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_lib nettle/bignum.h nettle_mpz_get_str_256 -lnettle -lhogweed -lgmp && enable nettle; } ||
    { check_lib gcrypt.h gcry_mpi_new -lgcrypt && enable gcrypt; }
fi

# libdc1394 check
if enabled libdc1394; then
    { check_lib dc1394/dc1394.h dc1394_new -ldc1394 -lraw1394 &&
        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

SDL_CONFIG="${cross_prefix}sdl-config"
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" $sdl_cflags &&
    enable sdl
else
  if "${SDL_CONFIG}" --version > /dev/null 2>&1; then
    sdl_cflags=$("${SDL_CONFIG}" --cflags)
    sdl_libs=$("${SDL_CONFIG}" --libs)
    check_func_headers SDL_version.h SDL_Linked_Version $sdl_cflags $sdl_libs &&
    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
fi
enabled sdl && add_cflags $sdl_cflags && add_extralibs $sdl_libs

texi2html --help 2> /dev/null | grep -q 'init-file' && enable texi2html || disable texi2html
makeinfo --version > /dev/null 2>&1 && enable makeinfo  || disable makeinfo
perl -v            > /dev/null 2>&1 && enable perl      || disable perl
pod2man --help     > /dev/null 2>&1 && enable pod2man   || disable pod2man
rsync --help 2> /dev/null | grep -q 'contimeout' && enable rsync_contimeout || disable rsync_contimeout

check_header linux/fb.h
check_header linux/videodev.h
check_header linux/videodev2.h
check_code cc linux/videodev2.h "struct v4l2_frmsizeenum vfse; vfse.discrete.width = 0;" && enable_safe struct_v4l2_frmivalenum_discrete

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_type "dshow.h" IBaseFilter

# 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
if check_struct sys/soundcard.h audio_buf_info bytes; then
    enable_safe sys/soundcard.h
else
    check_cc -D__BSD_VISIBLE -D__XSI_VISIBLE <<EOF && add_cppflags -D__BSD_VISIBLE -D__XSI_VISIBLE && enable_safe sys/soundcard.h
    #include <sys/soundcard.h>
    audio_buf_info abc;
EOF
fi
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 sem_timedwait &&
    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: libcdio-paranoia not found"
fi

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

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

enabled vaapi &&
    check_lib va/va.h vaInitialize -lva ||
    disable vaapi

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

enabled vdpau && enabled xlib &&
    check_lib2 "vdpau/vdpau.h vdpau/vdpau_x11.h" vdp_device_create_x11 -lvdpau &&
    enable vdpau_x11

# Funny iconv installations are not unusual, so check it after all flags have been set
disabled iconv || check_func_headers iconv.h iconv || check_lib2 iconv.h iconv -liconv || disable iconv

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 -Wno-pointer-to-int-cast
check_cflags -Wstrict-prototypes
enabled extra_warnings && check_cflags -Winline

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=libpostproc:libswresample:libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil:libavresample
enabled rpath && add_ldflags -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

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_video       \
                  -Wl,--wrap,avcodec_encode_video2      \
                  -Wl,--wrap,avcodec_encode_subtitle    \
                  -Wl,--wrap,sws_scale ||
    disable xmm_clobber_test

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

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

enabled ftrapv && check_cflags -ftrapv

check_cc -mno-red-zone <<EOF && noredzone_flags="-mno-red-zone"
int x;
EOF


if enabled icc; then
    # Just warnings, no remarks
    check_cflags -w1
    # -wd: Disable following warnings
    # 144, 167, 556: -Wno-pointer-sign
    # 188: enumerated type mixed with another type
    # 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 -wd144,167,188,556,1292,1419,10006,10148,10156
    # 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 ${icc_version%%.*} -ge 11 &&
            check_cflags -falign-stack=maintain-16-byte ||
            disable aligned_stack
    fi
elif enabled ccc; then
    # disable some annoying warnings
    add_cflags -msg_disable bitnotint
    add_cflags -msg_disable mixfuncvoid
    add_cflags -msg_disable nonstandcast
    add_cflags -msg_disable unsupieee
elif enabled gcc; then
    check_optflags -fno-tree-vectorize
    check_cflags -Werror=implicit-function-declaration
    check_cflags -Werror=missing-prototypes
    check_cflags -Werror=return-type
    check_cflags -Werror=vla
    enabled extra_warnings || check_disable_warning -Wno-maybe-uninitialized
elif enabled llvm_gcc; then
    check_cflags -mllvm -stack-alignment=16
elif enabled clang; then
    check_cflags -mllvm -stack-alignment=16
    check_cflags -Qunused-arguments
    check_cflags -Werror=implicit-function-declaration
    check_cflags -Werror=missing-prototypes
    check_cflags -Werror=return-type
elif enabled cparser; then
    add_cflags -Wno-missing-variable-declarations
    add_cflags -Wno-empty-statement
elif enabled armcc; then
    # 2523: use of inline assembler is deprecated
    add_cflags -W${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)
        disabled inline_asm || warn "inline asm disabled due to issues with it in ICL"
        disable inline_asm
    fi
fi

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

enable frame_thread_encoder

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

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

enabled threads && ! enabled pthreads && ! enabled atomics_native && die "non pthread threading without atomics not supported, try adding --enable-pthreads or --cpu=i486 or higher if you are on x86"


if test $target_os = "haiku"; then
    disable memalign
    disable posix_memalign
fi

! enabled_any memalign posix_memalign aligned_malloc &&
    enabled_any $need_memalign && enable memalign_hack

# add_dep lib dep
# -> enable ${lib}_deps_${dep}
# -> add $dep to ${lib}_deps only once
add_dep() {
    lib=$1
    dep=$2
    enabled "${lib}_deps_${dep}" && return 0
    enable  "${lib}_deps_${dep}"
    prepend "${lib}_deps" $dep
}

# merge deps lib components
# merge all ${component}_deps into ${lib}_deps and ${lib}_deps_*
merge_deps() {
    lib=$1
    shift
    for comp in $*; do
        enabled $comp || continue
        eval "dep=\"\$${comp}_deps\""
        for d in $dep; do
            add_dep $lib $d
        done
    done
}

merge_deps libavfilter $FILTER_LIST

echo "install prefix            $prefix"
echo "source path               $source_path"
echo "C compiler                $cc"
echo "C library                 $libc_type"
if test "$host_cc" != "$cc"; then
    echo "host C compiler           $host_cc"
    echo "host C library            $host_libc_type"
fi
echo "ARCH                      $arch ($cpu)"
if test "$build_suffix" != ""; then
    echo "build suffix              $build_suffix"
fi
if test "$progs_suffix" != ""; then
    echo "progs suffix              $progs_suffix"
fi
if test "$extra_version" != ""; then
    echo "version string suffix     $extra_version"
fi
echo "big-endian                ${bigendian-no}"
echo "runtime cpu detection     ${runtime_cpudetect-no}"
if enabled x86; then
    echo "${yasmexe}                      ${yasm-no}"
    echo "MMX enabled               ${mmx-no}"
    echo "MMXEXT enabled            ${mmxext-no}"
    echo "3DNow! enabled            ${amd3dnow-no}"
    echo "3DNow! extended enabled   ${amd3dnowext-no}"
    echo "SSE enabled               ${sse-no}"
    echo "SSSE3 enabled             ${ssse3-no}"
    echo "AVX enabled               ${avx-no}"
    echo "FMA4 enabled              ${fma4-no}"
    echo "i686 features enabled     ${i686-no}"
    echo "CMOV is fast              ${fast_cmov-no}"
    echo "EBX available             ${ebx_available-no}"
    echo "EBP available             ${ebp_available-no}"
fi
if enabled arm; then
    echo "ARMv5TE enabled           ${armv5te-no}"
    echo "ARMv6 enabled             ${armv6-no}"
    echo "ARMv6T2 enabled           ${armv6t2-no}"
    echo "VFP enabled               ${vfp-no}"
    echo "NEON enabled              ${neon-no}"
    echo "THUMB enabled             ${thumb-no}"
fi
if enabled mips; then
    echo "MIPS FPU enabled          ${mipsfpu-no}"
    echo "MIPS32R2 enabled          ${mips32r2-no}"
    echo "MIPS DSP R1 enabled       ${mipsdspr1-no}"
    echo "MIPS DSP R2 enabled       ${mipsdspr2-no}"
fi
if enabled ppc; then
    echo "AltiVec enabled           ${altivec-no}"
    echo "PPC 4xx optimizations     ${ppc4xx-no}"
    echo "dcbzl available           ${dcbzl-no}"
fi
if enabled sparc; then
    echo "VIS enabled               ${vis-no}"
fi
echo "debug symbols             ${debug-no}"
echo "strip symbols             ${stripping-no}"
echo "optimize for size         ${small-no}"
echo "optimizations             ${optimizations-no}"
echo "static                    ${static-no}"
echo "shared                    ${shared-no}"
echo "postprocessing support    ${postproc-no}"
echo "new filter support        ${avfilter-no}"
echo "network support           ${network-no}"
echo "threading support         ${thread_type-no}"
echo "safe bitstream reader     ${safe_bitstream_reader-no}"
echo "SDL support               ${sdl-no}"
echo "opencl enabled            ${opencl-no}"
echo "libzvbi enabled           ${libzvbi-no}"
echo "texi2html enabled         ${texi2html-no}"
echo "perl enabled              ${perl-no}"
echo "pod2man enabled           ${pod2man-no}"
echo "makeinfo enabled          ${makeinfo-no}"
test -n "$random_seed" &&
    echo "random seed               ${random_seed}"
echo

echo "External libraries:"
print_enabled '' $EXTERNAL_LIBRARY_LIST | print_3_columns
echo

for type in decoder encoder hwaccel parser demuxer muxer protocol filter bsf indev outdev; do
    echo "Enabled ${type}s:"
    eval list=\$$(toupper $type)_LIST
    print_enabled '_*' $list | print_3_columns
    echo
done

license="LGPL version 2.1 or later"
if enabled nonfree; then
    license="nonfree and unredistributable"
elif enabled gplv3; then
    license="GPL version 3 or later"
elif enabled lgplv3; then
    license="LGPL version 3 or later"
elif enabled gpl; then
    license="GPL version 2 or later"
fi

echo "License: $license"

echo "Creating config.mak, config.h, and doc/config.texi..."

test -e Makefile || echo "include $source_path/Makefile" > Makefile

enabled stripping || strip="echo skipping strip"

config_files="$TMPH config.mak doc/config.texi"

cat > config.mak <<EOF
# Automatically generated by configure - do not modify!
ifndef FFMPEG_CONFIG_MAK
FFMPEG_CONFIG_MAK=1
FFMPEG_CONFIGURATION=$FFMPEG_CONFIGURATION
prefix=$prefix
LIBDIR=\$(DESTDIR)$libdir
SHLIBDIR=\$(DESTDIR)$shlibdir
INCDIR=\$(DESTDIR)$incdir
BINDIR=\$(DESTDIR)$bindir
DATADIR=\$(DESTDIR)$datadir
DOCDIR=\$(DESTDIR)$docdir
MANDIR=\$(DESTDIR)$mandir
SRC_PATH=$source_path
ifndef MAIN_MAKEFILE
SRC_PATH:=\$(SRC_PATH:.%=..%)
endif
CC_IDENT=$cc_ident
ARCH=$arch
CC=$cc
CXX=$cxx
AS=$as
LD=$ld
DEPCC=$dep_cc
DEPCCFLAGS=$DEPCCFLAGS \$(CPPFLAGS)
DEPAS=$as
DEPASFLAGS=$DEPASFLAGS \$(CPPFLAGS)
YASM=$yasmexe
DEPYASM=$yasmexe
AR=$ar
ARFLAGS=$arflags
AR_O=$ar_o
RANLIB=$ranlib
STRIP=$strip
CP=cp -p
LN_S=$ln_s
CPPFLAGS=$CPPFLAGS
CFLAGS=$CFLAGS
CXXFLAGS=$CXXFLAGS
ASFLAGS=$ASFLAGS
AS_C=$AS_C
AS_O=$AS_O
CC_C=$CC_C
CC_E=$CC_E
CC_O=$CC_O
CXX_C=$CXX_C
CXX_O=$CXX_O
LD_O=$LD_O
LD_LIB=$LD_LIB
LD_PATH=$LD_PATH
DLLTOOL=$dlltool
WINDRES=$windres
DEPWINDRES=$dep_cc
LDFLAGS=$LDFLAGS
SHFLAGS=$(echo $($ldflags_filter $SHFLAGS))
ASMSTRIPFLAGS=$ASMSTRIPFLAGS
YASMFLAGS=$YASMFLAGS
BUILDSUF=$build_suffix
PROGSSUF=$progs_suffix
FULLNAME=$FULLNAME
LIBPREF=$LIBPREF
LIBSUF=$LIBSUF
LIBNAME=$LIBNAME
SLIBPREF=$SLIBPREF
SLIBSUF=$SLIBSUF
EXESUF=$EXESUF
EXTRA_VERSION=$extra_version
CCDEP=$CCDEP
CXXDEP=$CXXDEP
CCDEP_FLAGS=$CCDEP_FLAGS
ASDEP=$ASDEP
ASDEP_FLAGS=$ASDEP_FLAGS
CC_DEPFLAGS=$CC_DEPFLAGS
AS_DEPFLAGS=$AS_DEPFLAGS
HOSTCC=$host_cc