Import aom library

This is the reference implementation for the Alliance for Open Media's av1 video code.

The commit used was 4d668d7feb1f8abd809d1bca0418570a7f142a36.

1 files changed, 865 insertions, 0 deletions

diff --git a/third_party/aom/configure b/third_party/aom/configure
new file mode 100755
index 000000000..83ec996ce
--- /dev/null
+++ b/third_party/aom/configure
@@ -0,0 +1,865 @@
+#!/bin/sh
+##
+##  configure
+##
+##  This script is the front-end to the build system. It provides a similar
+##  interface to standard configure scripts with some extra bits for dealing
+##  with toolchains that differ from the standard POSIX interface and
+##  for extracting subsets of the source tree. In theory, reusable parts
+##  of this script were intended to live in build/make/configure.sh,
+##  but in practice, the line is pretty blurry.
+##
+##  This build system is based in part on the FFmpeg configure script.
+##
+
+#source_path="`dirname \"$0\"`"
+source_path=${0%/*}
+. "${source_path}/build/make/configure.sh"
+
+show_help(){
+    show_help_pre
+    cat << EOF
+Advanced options:
+  ${toggle_libs}                  libraries
+  ${toggle_examples}              examples
+  ${toggle_analyzer}              analyzer
+  ${toggle_docs}                  documentation
+  ${toggle_unit_tests}            unit tests
+  ${toggle_decode_perf_tests}     build decoder perf tests with unit tests
+  ${toggle_encode_perf_tests}     build encoder perf tests with unit tests
+  --cpu=CPU                       tune for the specified CPU (ARM: cortex-a8, X86: sse3)
+  --libc=PATH                     path to alternate libc
+  --size-limit=WxH                max size to allow in the decoder
+  --as={yasm|nasm|auto}           use specified assembler [auto, yasm preferred]
+  --sdk-path=PATH                 path to root of sdk (android builds only)
+  ${toggle_codec_srcs}            in/exclude codec library source code
+  ${toggle_debug_libs}            in/exclude debug version of libraries
+  ${toggle_static_msvcrt}         use static MSVCRT (VS builds only)
+  ${toggle_highbitdepth}          enable 16-bit generic pixel pipeline (used by high bitdepth profiles)
+  ${toggle_lowbitdepth}           enable 8-bit optimized pixel pipeline
+  ${toggle_av1}                  AV1 codec support
+  ${toggle_internal_stats}        output of encoder internal stats for debug, if supported (encoders)
+  ${toggle_postproc}              postprocessing
+  ${toggle_multithread}           multithreaded encoding and decoding
+  ${toggle_spatial_resampling}    spatial sampling (scaling) support
+  ${toggle_realtime_only}         enable this option while building for real-time encoding
+  ${toggle_onthefly_bitpacking}   enable on-the-fly bitpacking in real-time encoding
+  ${toggle_error_concealment}     enable this option to get a decoder which is able to conceal losses
+  ${toggle_coefficient_range_checking}
+                                  enable decoder to check if intermediate
+                                  transform coefficients are in valid range
+  ${toggle_runtime_cpu_detect}    runtime cpu detection
+  ${toggle_shared}                shared library support
+  ${toggle_static}                static library support
+  ${toggle_small}                 favor smaller size over speed
+  ${toggle_postproc_visualizer}   macro block / block level visualizers
+  ${toggle_webm_io}               enable input from and output to WebM container
+  ${toggle_libyuv}                enable libyuv
+  ${toggle_accounting}            enable bit accounting
+  ${toggle_inspection}            enable bitstream inspection
+
+Codecs:
+  Codecs can be selectively enabled or disabled individually, or by family:
+      --disable-<codec>
+  is equivalent to:
+      --disable-<codec>-encoder
+      --disable-<codec>-decoder
+
+  Codecs available in this distribution:
+EOF
+#restore editor state '
+
+    family="";
+    last_family="";
+    c="";
+    str="";
+    for c in ${CODECS}; do
+        family=${c%_*}
+        if [ "${family}" != "${last_family}" ]; then
+            [ -z "${str}" ] || echo "${str}"
+            str="$(printf '    %10s:' ${family})"
+        fi
+        str="${str} $(printf '%10s' ${c#*_})"
+        last_family=${family}
+    done
+    echo "${str}"
+    show_help_post
+}
+
+##
+## BEGIN APPLICATION SPECIFIC CONFIGURATION
+##
+
+# all_platforms is a list of all supported target platforms. Maintain
+# alphabetically by architecture, generic-gnu last.
+all_platforms="${all_platforms} arm64-darwin-gcc"
+all_platforms="${all_platforms} arm64-linux-gcc"
+all_platforms="${all_platforms} armv6-linux-rvct"
+all_platforms="${all_platforms} armv6-linux-gcc"
+all_platforms="${all_platforms} armv6-none-rvct"
+all_platforms="${all_platforms} armv7-android-gcc"   #neon Cortex-A8
+all_platforms="${all_platforms} armv7-darwin-gcc"    #neon Cortex-A8
+all_platforms="${all_platforms} armv7-linux-rvct"    #neon Cortex-A8
+all_platforms="${all_platforms} armv7-linux-gcc"     #neon Cortex-A8
+all_platforms="${all_platforms} armv7-none-rvct"     #neon Cortex-A8
+all_platforms="${all_platforms} armv7-win32-vs12"
+all_platforms="${all_platforms} armv7-win32-vs14"
+all_platforms="${all_platforms} armv7s-darwin-gcc"
+all_platforms="${all_platforms} armv8-linux-gcc"
+all_platforms="${all_platforms} mips32-linux-gcc"
+all_platforms="${all_platforms} mips64-linux-gcc"
+all_platforms="${all_platforms} sparc-solaris-gcc"
+all_platforms="${all_platforms} x86-android-gcc"
+all_platforms="${all_platforms} x86-darwin8-gcc"
+all_platforms="${all_platforms} x86-darwin8-icc"
+all_platforms="${all_platforms} x86-darwin9-gcc"
+all_platforms="${all_platforms} x86-darwin9-icc"
+all_platforms="${all_platforms} x86-darwin10-gcc"
+all_platforms="${all_platforms} x86-darwin11-gcc"
+all_platforms="${all_platforms} x86-darwin12-gcc"
+all_platforms="${all_platforms} x86-darwin13-gcc"
+all_platforms="${all_platforms} x86-darwin14-gcc"
+all_platforms="${all_platforms} x86-darwin15-gcc"
+all_platforms="${all_platforms} x86-darwin16-gcc"
+all_platforms="${all_platforms} x86-iphonesimulator-gcc"
+all_platforms="${all_platforms} x86-linux-gcc"
+all_platforms="${all_platforms} x86-linux-icc"
+all_platforms="${all_platforms} x86-os2-gcc"
+all_platforms="${all_platforms} x86-solaris-gcc"
+all_platforms="${all_platforms} x86-win32-gcc"
+all_platforms="${all_platforms} x86-win32-vs12"
+all_platforms="${all_platforms} x86-win32-vs14"
+all_platforms="${all_platforms} x86_64-android-gcc"
+all_platforms="${all_platforms} x86_64-darwin9-gcc"
+all_platforms="${all_platforms} x86_64-darwin10-gcc"
+all_platforms="${all_platforms} x86_64-darwin11-gcc"
+all_platforms="${all_platforms} x86_64-darwin12-gcc"
+all_platforms="${all_platforms} x86_64-darwin13-gcc"
+all_platforms="${all_platforms} x86_64-darwin14-gcc"
+all_platforms="${all_platforms} x86_64-darwin15-gcc"
+all_platforms="${all_platforms} x86_64-darwin16-gcc"
+all_platforms="${all_platforms} x86_64-iphonesimulator-gcc"
+all_platforms="${all_platforms} x86_64-linux-gcc"
+all_platforms="${all_platforms} x86_64-linux-icc"
+all_platforms="${all_platforms} x86_64-solaris-gcc"
+all_platforms="${all_platforms} x86_64-win64-gcc"
+all_platforms="${all_platforms} x86_64-win64-vs12"
+all_platforms="${all_platforms} x86_64-win64-vs14"
+all_platforms="${all_platforms} generic-gnu"
+
+# all_targets is a list of all targets that can be configured
+# note that these should be in dependency order for now.
+all_targets="libs examples docs"
+
+# all targets available are enabled, by default.
+for t in ${all_targets}; do
+    [ -f "${source_path}/${t}.mk" ] && enable_feature ${t}
+done
+
+if ! perl --version >/dev/null; then
+    die "Perl is required to build"
+fi
+
+
+if [ "`cd \"${source_path}\" && pwd`" != "`pwd`" ]; then
+  # test to see if source_path already configured
+  if [ -f "${source_path}/aom_config.h" ]; then
+    die "source directory already configured; run 'make distclean' there first"
+  fi
+fi
+
+# check installed doxygen version
+doxy_version=$(doxygen --version 2>/dev/null)
+doxy_major=${doxy_version%%.*}
+if [ ${doxy_major:-0} -ge 1 ]; then
+    doxy_version=${doxy_version#*.}
+    doxy_minor=${doxy_version%%.*}
+    doxy_patch=${doxy_version##*.}
+
+    [ $doxy_major -gt 1 ] && enable_feature doxygen
+    [ $doxy_minor -gt 5 ] && enable_feature doxygen
+    [ $doxy_minor -eq 5 ] && [ $doxy_patch -ge 3 ] && enable_feature doxygen
+fi
+
+# disable codecs when their source directory does not exist
+[ -d "${source_path}/av1" ] || disable_codec av1
+
+# install everything except the sources, by default. sources will have
+# to be enabled when doing dist builds, since that's no longer a common
+# case.
+enabled doxygen && enable_feature install_docs
+enable_feature install_bins
+enable_feature install_libs
+
+enable_feature static
+enable_feature optimizations
+enable_feature dependency_tracking
+enable_feature spatial_resampling
+enable_feature multithread
+enable_feature os_support
+
+CODECS="
+    av1_encoder
+    av1_decoder
+"
+CODEC_FAMILIES="
+    av1
+"
+
+ARCH_LIST="
+    arm
+    mips
+    x86
+    x86_64
+"
+ARCH_EXT_LIST_X86="
+    mmx
+    sse
+    sse2
+    sse3
+    ssse3
+    sse4_1
+    avx
+    avx2
+"
+ARCH_EXT_LIST="
+    edsp
+    media
+    neon
+    neon_asm
+
+    mips32
+    dspr2
+    msa
+    mips64
+
+    ${ARCH_EXT_LIST_X86}
+"
+HAVE_LIST="
+    ${ARCH_EXT_LIST}
+    aom_ports
+    fexcept
+    pthread_h
+    unistd_h
+    wxwidgets
+"
+EXPERIMENT_LIST="
+    fp_mb_stats
+    cdef
+    var_tx
+    rect_tx
+    ref_mv
+    tpl_mv
+    dual_filter
+    convolve_round
+    compound_round
+    ext_tx
+    tx64x64
+    sub8x8_mc
+    ext_intra
+    intra_interp
+    filter_intra
+    intrabc
+    ext_inter
+    interintra
+    wedge
+    compound_segment
+    ext_refs
+    global_motion
+    new_quant
+    supertx
+    ans
+    ec_multisymbol
+    new_tokenset
+    loop_restoration
+    ext_partition
+    ext_partition_types
+    unpoison_partition_ctx
+    ext_tile
+    motion_var
+    ncobmc
+    warped_motion
+    q_adapt_probs
+    subframe_prob_update
+    bitstream_debug
+    alt_intra
+    palette
+    palette_delta_encoding
+    daala_ec
+    rawbits
+    ec_smallmul
+    pvq
+    cfl
+    xiphrc
+    cb4x4
+    chroma_2x2
+    chroma_sub8x8
+    frame_size
+    delta_q
+    ext_delta_q
+    adapt_scan
+    filter_7bit
+    parallel_deblocking
+    parallel_deblocking_15tap
+    loopfiltering_across_tiles
+    tile_groups
+    ec_adapt
+    tempmv_signaling
+    rd_debug
+    reference_buffer
+    coef_interleave
+    entropy_stats
+    masked_tx
+    dependent_horztiles
+    daala_dist
+    tripred
+    palette_throughput
+    ref_adapt
+    lv_map
+    txk_sel
+    mv_compress
+    frame_superres
+    new_multisymbol
+    compound_singleref
+    aom_qm
+    lowdelay_compound
+"
+CONFIG_LIST="
+    dependency_tracking
+    external_build
+    install_docs
+    install_bins
+    install_libs
+    install_srcs
+    debug
+    gprof
+    gcov
+    rvct
+    gcc
+    msvs
+    pic
+    big_endian
+
+    codec_srcs
+    debug_libs
+
+    runtime_cpu_detect
+    postproc
+    multithread
+    internal_stats
+    ${CODECS}
+    ${CODEC_FAMILIES}
+    encoders
+    decoders
+    static_msvcrt
+    spatial_resampling
+    realtime_only
+    onthefly_bitpacking
+    error_concealment
+    shared
+    static
+    small
+    postproc_visualizer
+    os_support
+    unit_tests
+    webm_io
+    libyuv
+    accounting
+    inspection
+    decode_perf_tests
+    encode_perf_tests
+    coefficient_range_checking
+    lowbitdepth
+    highbitdepth
+    experimental
+    size_limit
+    ${EXPERIMENT_LIST}
+    analyzer
+"
+CMDLINE_SELECT="
+    dependency_tracking
+    external_build
+    extra_warnings
+    werror
+    install_docs
+    install_bins
+    install_libs
+    install_srcs
+    debug
+    gprof
+    gcov
+    pic
+    optimizations
+    ccache
+    runtime_cpu_detect
+    thumb
+
+    libs
+    examples
+    analyzer
+    docs
+    libc
+    as
+    size_limit
+    codec_srcs
+    debug_libs
+
+    postproc
+    multithread
+    internal_stats
+    ${CODECS}
+    ${CODEC_FAMILIES}
+    static_msvcrt
+    spatial_resampling
+    realtime_only
+    onthefly_bitpacking
+    error_concealment
+    shared
+    static
+    small
+    postproc_visualizer
+    unit_tests
+    webm_io
+    libyuv
+    accounting
+    inspection
+    decode_perf_tests
+    encode_perf_tests
+    coefficient_range_checking
+    lowbitdepth
+    aom_highbitdepth
+    highbitdepth
+    experimental
+"
+
+process_cmdline() {
+    for opt do
+        optval="${opt#*=}"
+        case "$opt" in
+        --disable-codecs)
+          for c in ${CODEC_FAMILIES}; do disable_codec $c; done
+          ;;
+        --enable-?*|--disable-?*)
+        eval `echo "$opt" | sed 's/--/action=/;s/-/ option=/;s/-/_/g'`
+        if is_in ${option} ${EXPERIMENT_LIST}; then
+            if enabled experimental; then
+                ${action}_feature $option
+            else
+                log_echo "Ignoring $opt -- not in experimental mode."
+            fi
+        elif is_in ${option} "${CODECS} ${CODEC_FAMILIES}"; then
+            ${action}_codec ${option}
+        else
+            process_common_cmdline $opt
+        fi
+        ;;
+        *) process_common_cmdline "$opt"
+        ;;
+        esac
+    done
+}
+
+post_process_cmdline() {
+    c=""
+
+    # Enable all detected codecs, if they haven't been disabled
+    for c in ${CODECS}; do soft_enable $c; done
+
+    # Enable the codec family if any component of that family is enabled
+    for c in ${CODECS}; do
+        enabled $c && enable_feature ${c%_*}
+    done
+
+    # Set the {en,de}coders variable if any algorithm in that class is enabled
+    for c in ${CODECS}; do
+        enabled ${c} && enable_feature ${c##*_}s
+    done
+
+    # Enable adopted experiments by default
+    soft_enable ref_mv
+    soft_enable cb4x4
+    soft_enable filter_7bit
+    soft_enable reference_buffer
+    soft_enable delta_q
+    soft_enable tile_groups
+    soft_enable rect_tx
+    soft_enable global_motion
+    soft_enable cdef
+    soft_enable ec_adapt
+    soft_enable new_tokenset
+    soft_enable ext_intra
+    soft_enable mv_compress
+    soft_enable ext_refs
+    soft_enable dual_filter
+    soft_enable motion_var
+    soft_enable warped_motion
+    soft_enable ext_delta_q
+
+    # Backwards/jenkins compatibility with --enable-aom-highbitdepth
+    enabled aom_highbitdepth && enable_feature highbitdepth
+
+    # Enable low-bitdepth pixel pipeline by default
+    soft_enable lowbitdepth
+
+    ! enabled ans && soft_enable daala_ec
+    soft_enable ec_multisymbol
+    soft_enable palette
+    soft_enable alt_intra
+    soft_enable palette_throughput
+
+    # Fix up experiment dependencies
+    enabled pvq && enable_feature ec_adapt
+    enabled ec_adapt && enable_feature ec_multisymbol
+    enabled new_tokenset && enable_feature ec_multisymbol
+    enabled new_multisymbol && enable_feature ec_multisymbol
+    enabled ec_multisymbol && ! enabled ans && soft_enable daala_ec
+    enabled ec_multisymbol && ! enabled daala_ec && soft_enable ans
+    enabled palette_throughput && soft_enable palette
+    enabled ext_delta_q && soft_enable delta_q
+    enabled txk_sel && soft_enable lv_map
+    enabled compound_round && soft_enable convolve_round
+    if enabled rawbits && ! enabled daala_ec; then
+      log_echo "rawbits requires daala_ec, so disabling rawbits"
+      disable_feature rawbits
+    fi
+    if enabled ec_smallmul && ! enabled daala_ec; then
+      log_echo "ec_smallmul requires daala_ec, so disabling ec_smallmul"
+      disable_feature ec_smallmul
+    fi
+    if enabled ext_tile; then
+      log_echo "ext_tile not compatible with reference_buffer, so"
+      log_echo "disabling reference_buffer"
+      disable_feature reference_buffer
+    fi
+    if enabled ext_tile; then
+      log_echo "ext_tile not compatible with tile_groups, so"
+      log_echo "disabling tile_groups"
+      disable_feature tile_groups
+    fi
+    # Enable accounting and inspection when building the analyzer
+    if enabled analyzer; then
+      soft_enable accounting
+      soft_enable inspection
+    fi
+}
+
+process_targets() {
+    enabled child || write_common_config_banner
+    write_common_target_config_h ${BUILD_PFX}aom_config.h
+    write_common_config_targets
+
+    # Calculate the default distribution name, based on the enabled features
+    cf=""
+    DIST_DIR=aom
+    for cf in $CODEC_FAMILIES; do
+        if enabled ${cf}_encoder && enabled ${cf}_decoder; then
+            DIST_DIR="${DIST_DIR}-${cf}"
+        elif enabled ${cf}_encoder; then
+            DIST_DIR="${DIST_DIR}-${cf}cx"
+        elif enabled ${cf}_decoder; then
+            DIST_DIR="${DIST_DIR}-${cf}dx"
+        fi
+    done
+    enabled debug_libs && DIST_DIR="${DIST_DIR}-debug"
+    enabled codec_srcs && DIST_DIR="${DIST_DIR}-src"
+    ! enabled postproc && DIST_DIR="${DIST_DIR}-nopost"
+    ! enabled multithread && DIST_DIR="${DIST_DIR}-nomt"
+    ! enabled install_docs && DIST_DIR="${DIST_DIR}-nodocs"
+    DIST_DIR="${DIST_DIR}-${tgt_isa}-${tgt_os}"
+    case "${tgt_os}" in
+    win*) enabled static_msvcrt && DIST_DIR="${DIST_DIR}mt" || DIST_DIR="${DIST_DIR}md"
+          DIST_DIR="${DIST_DIR}-${tgt_cc}"
+          ;;
+    esac
+    if [ -f "${source_path}/build/make/version.sh" ]; then
+        ver=`"$source_path/build/make/version.sh" --bare "$source_path"`
+        DIST_DIR="${DIST_DIR}-${ver}"
+        VERSION_STRING=${ver}
+        ver=${ver%%-*}
+        VERSION_PATCH=${ver##*.}
+        ver=${ver%.*}
+        VERSION_MINOR=${ver##*.}
+        ver=${ver#v}
+        VERSION_MAJOR=${ver%.*}
+    fi
+    enabled child || cat <<EOF >> config.mk
+
+PREFIX=${prefix}
+ifeq (\$(MAKECMDGOALS),dist)
+DIST_DIR?=${DIST_DIR}
+else
+DIST_DIR?=\$(DESTDIR)${prefix}
+endif
+LIBSUBDIR=${libdir##${prefix}/}
+
+VERSION_STRING=${VERSION_STRING}
+
+VERSION_MAJOR=${VERSION_MAJOR}
+VERSION_MINOR=${VERSION_MINOR}
+VERSION_PATCH=${VERSION_PATCH}
+
+CONFIGURE_ARGS=${CONFIGURE_ARGS}
+EOF
+    enabled child || echo "CONFIGURE_ARGS?=${CONFIGURE_ARGS}" >> config.mk
+
+    #
+    # Write makefiles for all enabled targets
+    #
+    for tgt in libs examples docs solution; do
+        tgt_fn="$tgt-$toolchain.mk"
+
+        if enabled $tgt; then
+            echo "Creating makefiles for ${toolchain} ${tgt}"
+            write_common_target_config_mk $tgt_fn ${BUILD_PFX}aom_config.h
+            #write_${tgt}_config
+        fi
+    done
+
+}
+
+process_detect() {
+    if enabled shared; then
+        # Can only build shared libs on a subset of platforms. Doing this check
+        # here rather than at option parse time because the target auto-detect
+        # magic happens after the command line has been parsed.
+        case "${tgt_os}" in
+        linux|os2|darwin*|iphonesimulator*)
+            # Supported platforms
+            ;;
+        *)
+            if enabled gnu; then
+                echo "--enable-shared is only supported on ELF; assuming this is OK"
+            else
+                die "--enable-shared only supported on ELF, OS/2, and Darwin for now"
+            fi
+            ;;
+        esac
+    fi
+    if [ -z "$CC" ] || enabled external_build; then
+        echo "Bypassing toolchain for environment detection."
+        enable_feature external_build
+        check_header() {
+            log fake_check_header "$@"
+            header=$1
+            shift
+            var=`echo $header | sed 's/[^A-Za-z0-9_]/_/g'`
+            disable_feature $var
+            # Headers common to all environments
+            case $header in
+                stdio.h)
+                    true;
+                ;;
+                *)
+                    result=false
+                    for d in "$@"; do
+                        [ -f "${d##-I}/$header" ] && result=true && break
+                    done
+                    ${result:-true}
+            esac && enable_feature $var
+
+            # Specialize windows and POSIX environments.
+            case $toolchain in
+                *-win*-*)
+                    # Don't check for any headers in Windows builds.
+                    false
+                ;;
+                *)
+                    case $header in
+                        pthread.h) true;;
+                        unistd.h) true;;
+                        *) false;;
+                    esac && enable_feature $var
+            esac
+            enabled $var
+        }
+        check_ld() {
+            true
+        }
+    fi
+    check_header stdio.h || die "Unable to invoke compiler: ${CC} ${CFLAGS}"
+    check_ld <<EOF || die "Toolchain is unable to link executables"
+int main(void) {return 0;}
+EOF
+    # check system headers
+    check_header pthread.h
+    check_header unistd.h # for sysconf(3) and friends.
+
+    check_header aom/aom_integer.h -I${source_path} && enable_feature aom_ports
+
+    check_ld <<EOF && enable_feature fexcept
+#define _GNU_SOURCE
+#include <fenv.h>
+int main(void) { (void)feenableexcept(FE_DIVBYZERO | FE_INVALID); return 0; }
+EOF
+}
+
+process_toolchain() {
+    process_common_toolchain
+
+    # Enable some useful compiler flags
+    if enabled gcc; then
+        enabled werror && check_add_cflags -Werror
+        check_add_cflags -Wall
+        check_add_cflags -Wdisabled-optimization
+        check_add_cflags -Wfloat-conversion
+        check_add_cflags -Wpointer-arith
+        check_add_cflags -Wtype-limits
+        check_add_cflags -Wvla
+        check_add_cflags -Wimplicit-function-declaration
+        check_add_cflags -Wuninitialized
+        check_add_cflags -Wunused
+        check_add_cflags -Wsign-compare
+        check_add_cflags -Wlogical-op
+        check_add_cflags -Wstack-usage=320000
+        # Enabling the following warning (in combination with -Wunused above)
+        # for C++ generates errors in third_party code including googletest and
+        # libyuv. So enable it only for C code.
+        check_cflags "-Wextra" && add_cflags_only "-Wextra"
+        # Enabling the following warning for C++ generates some useless warnings
+        # about some function parameters shadowing class member function names.
+        # So, only enable this warning for C code.
+        check_cflags "-Wshadow" && add_cflags_only "-Wshadow"
+        if enabled mips || [ -z "${INLINE}" ]; then
+          enabled extra_warnings || check_add_cflags -Wno-unused-function
+        fi
+        # gtest makes heavy use of undefined pre-processor symbols
+        check_cflags "-Wundef" && add_cflags_only "-Wundef"
+        # Avoid this warning for third_party C++ sources. Some reorganization
+        # would be needed to apply this only to test/*.cc.
+        check_cflags -Wshorten-64-to-32 && add_cflags_only -Wshorten-64-to-32
+    fi
+
+    if enabled icc; then
+        enabled werror && check_add_cflags -Werror
+        check_add_cflags -Wall
+        check_add_cflags -Wpointer-arith
+
+        # ICC has a number of floating point optimizations that we disable
+        # in favor of deterministic output WRT to other compilers
+        add_cflags -fp-model precise
+    fi
+
+    if enabled analyzer; then
+      soft_enable wxwidgets
+      if ! wx-config --version > /dev/null; then
+        die "Couldn't find wx-config"
+      fi
+
+      add_cxxflags_only $(wx-config --cppflags)
+      add_extralibs $(wx-config --libs)
+    fi
+
+    # Enable extra, harmless warnings. These might provide additional insight
+    # to what the compiler is doing and why, but in general, but they shouldn't
+    # be treated as fatal, even if we're treating warnings as errors.
+    GCC_EXTRA_WARNINGS="
+        -Wdisabled-optimization
+        -Winline
+    "
+    enabled gcc && EXTRA_WARNINGS="${GCC_EXTRA_WARNINGS}"
+    RVCT_EXTRA_WARNINGS="
+        --remarks
+    "
+    enabled rvct && EXTRA_WARNINGS="${RVCT_EXTRA_WARNINGS}"
+    if enabled extra_warnings; then
+        for w in ${EXTRA_WARNINGS}; do
+            check_add_cflags ${w}
+            enabled gcc && enabled werror && check_add_cflags -Wno-error=${w}
+        done
+    fi
+
+    # ccache only really works on gcc toolchains
+    enabled gcc || soft_disable ccache
+
+    # Enable the postbuild target if building for visual studio.
+    case "$tgt_cc" in
+        vs*) enable_feature msvs
+             enable_feature solution
+             vs_version=${tgt_cc##vs}
+             VCPROJ_SFX=vcxproj
+             gen_vcproj_cmd=${source_path}/build/make/gen_msvs_vcxproj.sh
+             enabled werror && gen_vcproj_cmd="${gen_vcproj_cmd} --enable-werror"
+             all_targets="${all_targets} solution"
+             INLINE="__forceinline"
+        ;;
+    esac
+
+    # Other toolchain specific defaults
+    case $toolchain in x86*) soft_enable postproc;; esac
+
+    if enabled postproc_visualizer; then
+        enabled postproc || die "postproc_visualizer requires postproc to be enabled"
+    fi
+
+    # Enable unit tests by default if we have a working C++ compiler.
+    case "$toolchain" in
+        *-vs*)
+            soft_enable unit_tests
+            soft_enable webm_io
+            soft_enable libyuv
+        ;;
+        *-android-*)
+            soft_enable webm_io
+            soft_enable libyuv
+            # GTestLog must be modified to use Android logging utilities.
+        ;;
+        *-darwin-*)
+            # iOS/ARM builds do not work with gtest. This does not match
+            # x86 targets.
+        ;;
+        *-iphonesimulator-*)
+            soft_enable webm_io
+            soft_enable libyuv
+        ;;
+        *-win*)
+            # Some mingw toolchains don't have pthread available by default.
+            # Treat these more like visual studio where threading in gtest
+            # would be disabled for the same reason.
+            check_cxx "$@" <<EOF && soft_enable unit_tests
+int z;
+EOF
+            check_cxx "$@" <<EOF && soft_enable webm_io
+int z;
+EOF
+            check_cxx "$@" <<EOF && soft_enable libyuv
+int z;
+EOF
+        ;;
+        *)
+            enabled pthread_h && check_cxx "$@" <<EOF && soft_enable unit_tests
+int z;
+EOF
+            check_cxx "$@" <<EOF && soft_enable webm_io
+int z;
+EOF
+            check_cxx "$@" <<EOF && soft_enable libyuv
+int z;
+EOF
+        ;;
+    esac
+    # libwebm needs to be linked with C++ standard library
+    enabled webm_io && LD=${CXX}
+
+    # append any user defined extra cflags
+    if [ -n "${extra_cflags}" ] ; then
+        check_add_cflags ${extra_cflags} || \
+        die "Requested extra CFLAGS '${extra_cflags}' not supported by compiler"
+    fi
+    if [ -n "${extra_cxxflags}" ]; then
+        check_add_cxxflags ${extra_cxxflags} || \
+        die "Requested extra CXXFLAGS '${extra_cxxflags}' not supported by compiler"
+    fi
+}
+
+
+##
+## END APPLICATION SPECIFIC CONFIGURATION
+##
+CONFIGURE_ARGS="$@"
+process "$@"
+print_webm_license ${BUILD_PFX}aom_config.c "/*" " */"
+cat <<EOF >> ${BUILD_PFX}aom_config.c
+#include "aom/aom_codec.h"
+static const char* const cfg = "$CONFIGURE_ARGS";
+const char *aom_codec_build_config(void) {return cfg;}
+EOF