Update libaom to commit ID 1e227d41f0616de9548a673a83a21ef990b62591

13 files changed, 1233 insertions, 133 deletions

diff --git a/third_party/aom/build/cmake/aom_config_defaults.cmake b/third_party/aom/build/cmake/aom_config_defaults.cmake
index 19af5c43b..a07438cfe 100644
--- a/third_party/aom/build/cmake/aom_config_defaults.cmake
+++ b/third_party/aom/build/cmake/aom_config_defaults.cmake
@@ -7,90 +7,190 @@
 # at www.aomedia.org/license/software. If the Alliance for Open Media Patent
 # License 1.0 was not distributed with this source code in the PATENTS file, you
 # can obtain it at www.aomedia.org/license/patent.
+
+include("${AOM_ROOT}/build/cmake/util.cmake")
+
+# This file sets default values for libaom configuration variables. All libaom
+# config variables are added to the CMake variable cache via the macros provided
+# in util.cmake.
+
 #
-# Defaults for every libaom configuration variable. Here we add all libaom
-# config variables to the cmake variable cache, but omit the FORCE parameter to
-# allow users to specify values when executing cmake to generate build files.
-# Values here are used only if not set by the user.
-set(INLINE "" CACHE STRING "Sets INLINE value for current target.")
+# The variables in this section of the file are detected at configuration time,
+# but can be overridden via the use of CONFIG_* and ENABLE_* values also defined
+# in this file.
+#
+
+set_aom_detect_var(INLINE "" STRING "Sets INLINE value for current target.")
 
 # CPUs.
-set(ARCH_ARM 0 CACHE NUMBER "Enables ARM architecture.")
-set(ARCH_MIPS 0 CACHE NUMBER "Enables MIPS architecture.")
-set(ARCH_PPC 0 CACHE NUMBER "Enables PPC architecture.")
-set(ARCH_X86 0 CACHE NUMBER "Enables X86 architecture.")
-set(ARCH_X86_64 0 CACHE NUMBER "Enables X86_64 architecture.")
-
-# ARM optimization flags.
-set(HAVE_NEON 0 CACHE NUMBER "Enables NEON intrinsics optimizations.")
-
-# MIPS optimization flags.
-set(HAVE_DSPR2 0 CACHE NUMBER "Enables DSPR2 optimizations.")
-set(HAVE_MIPS32 0 CACHE NUMBER "Enables MIPS32 optimizations.")
-set(HAVE_MIPS64 0 CACHE NUMBER "Enables MIPS64 optimizations. ")
-set(HAVE_MSA 0 CACHE NUMBER "Enables MSA optimizations.")
-
-# PPC optimization flags.
-set(HAVE_VSX 0 CACHE NUMBER "Enables VSX optimizations.")
-
-# x86/x86_64 optimization flags.
-set(HAVE_AVX 0 CACHE NUMBER "Enables AVX optimizations.")
-set(HAVE_AVX2 0 CACHE NUMBER "Enables AVX2 optimizations.")
-set(HAVE_MMX 0 CACHE NUMBER "Enables MMX optimizations. ")
-set(HAVE_SSE 0 CACHE NUMBER "Enables SSE optimizations.")
-set(HAVE_SSE2 0 CACHE NUMBER "Enables SSE2 optimizations.")
-set(HAVE_SSE3 0 CACHE NUMBER "Enables SSE3 optimizations.")
-set(HAVE_SSE4_1 0 CACHE NUMBER "Enables SSE 4.1 optimizations.")
-set(HAVE_SSE4_2 0 CACHE NUMBER "Enables SSE 4.2 optimizations.")
-set(HAVE_SSSE3 0 CACHE NUMBER "Enables SSSE3 optimizations.")
+set_aom_detect_var(ARCH_ARM 0 NUMBER "Enables ARM architecture.")
+set_aom_detect_var(ARCH_MIPS 0 NUMBER "Enables MIPS architecture.")
+set_aom_detect_var(ARCH_PPC 0 NUMBER "Enables PPC architecture.")
+set_aom_detect_var(ARCH_X86 0 NUMBER "Enables X86 architecture.")
+set_aom_detect_var(ARCH_X86_64 0 NUMBER "Enables X86_64 architecture.")
+
+# ARM feature flags.
+set_aom_detect_var(HAVE_NEON 0 NUMBER "Enables NEON intrinsics optimizations.")
+
+# MIPS feature flags.
+set_aom_detect_var(HAVE_DSPR2 0 NUMBER "Enables DSPR2 optimizations.")
+set_aom_detect_var(HAVE_MIPS32 0 NUMBER "Enables MIPS32 optimizations.")
+set_aom_detect_var(HAVE_MIPS64 0 NUMBER "Enables MIPS64 optimizations. ")
+set_aom_detect_var(HAVE_MSA 0 NUMBER "Enables MSA optimizations.")
+
+# PPC feature flags.
+set_aom_detect_var(HAVE_VSX 0 NUMBER "Enables VSX optimizations.")
+
+# x86/x86_64 feature flags.
+set_aom_detect_var(HAVE_AVX 0 NUMBER "Enables AVX optimizations.")
+set_aom_detect_var(HAVE_AVX2 0 NUMBER "Enables AVX2 optimizations.")
+set_aom_detect_var(HAVE_MMX 0 NUMBER "Enables MMX optimizations. ")
+set_aom_detect_var(HAVE_SSE 0 NUMBER "Enables SSE optimizations.")
+set_aom_detect_var(HAVE_SSE2 0 NUMBER "Enables SSE2 optimizations.")
+set_aom_detect_var(HAVE_SSE3 0 NUMBER "Enables SSE3 optimizations.")
+set_aom_detect_var(HAVE_SSE4_1 0 NUMBER "Enables SSE 4.1 optimizations.")
+set_aom_detect_var(HAVE_SSE4_2 0 NUMBER "Enables SSE 4.2 optimizations.")
+set_aom_detect_var(HAVE_SSSE3 0 NUMBER "Enables SSSE3 optimizations.")
 
 # Flags describing the build environment.
-set(HAVE_FEXCEPT 0 CACHE NUMBER "Internal flag, GNU fenv.h present for target.")
-set(HAVE_PTHREAD_H 0 CACHE NUMBER "Internal flag, target pthread support.")
-set(HAVE_UNISTD_H 0 CACHE NUMBER "Internal flag, unistd.h present for target.")
-set(HAVE_WXWIDGETS 0 CACHE NUMBER "WxWidgets present.")
+set_aom_detect_var(HAVE_FEXCEPT 0 NUMBER
+                   "Internal flag, GNU fenv.h present for target.")
+set_aom_detect_var(HAVE_PTHREAD_H 0 NUMBER
+                   "Internal flag, target pthread support.")
+set_aom_detect_var(HAVE_UNISTD_H 0 NUMBER
+                   "Internal flag, unistd.h present for target.")
+set_aom_detect_var(HAVE_WXWIDGETS 0 NUMBER "WxWidgets present.")
+
+#
+# Variables in this section can be set from the CMake command line or from
+# within the CMake GUI. The variables control libaom features.
+#
 
 # Build configuration flags.
-set(CONFIG_AV1_DECODER 1 CACHE NUMBER "Enable AV1 decoder.")
-set(CONFIG_AV1_ENCODER 1 CACHE NUMBER "Enable AV1 encoder.")
-set(CONFIG_BIG_ENDIAN 0 CACHE NUMBER "Internal flag.")
-set(CONFIG_GCC 0 CACHE NUMBER "Building with GCC (detected).")
-set(CONFIG_GCOV 0 CACHE NUMBER "Enable gcov support.")
-set(CONFIG_GPROF 0 CACHE NUMBER "Enable gprof support.")
-set(CONFIG_LIBYUV 1 CACHE NUMBER "Enables libyuv scaling/conversion support.")
-set(CONFIG_MSVS 0 CACHE NUMBER "Building with MS Visual Studio (detected).")
-set(CONFIG_MULTITHREAD 1 CACHE NUMBER "Multithread support.")
-set(CONFIG_OS_SUPPORT 0 CACHE NUMBER "Internal flag.")
-set(CONFIG_PIC 0 CACHE NUMBER "Build with PIC enabled.")
-set(CONFIG_RUNTIME_CPU_DETECT 1 CACHE NUMBER "Runtime CPU detection support.")
-set(CONFIG_SHARED 0 CACHE NUMBER "Build shared libs.")
-set(CONFIG_STATIC 1 CACHE NUMBER "Build static libs.")
-set(CONFIG_WEBM_IO 1 CACHE NUMBER "Enables WebM support.")
+set_aom_config_var(AOM_RTCD_FLAGS "" STRING
+                   "Arguments to pass to rtcd.pl. Separate with ';'")
+set_aom_config_var(CONFIG_AV1_DECODER 1 NUMBER "Enable AV1 decoder.")
+set_aom_config_var(CONFIG_AV1_ENCODER 1 NUMBER "Enable AV1 encoder.")
+set_aom_config_var(CONFIG_BIG_ENDIAN 0 NUMBER "Internal flag.")
+set_aom_config_var(CONFIG_GCC 0 NUMBER "Building with GCC (detect).")
+set_aom_config_var(CONFIG_GCOV 0 NUMBER "Enable gcov support.")
+set_aom_config_var(CONFIG_GPROF 0 NUMBER "Enable gprof support.")
+set_aom_config_var(CONFIG_LIBYUV 1 NUMBER
+                   "Enables libyuv scaling/conversion support.")
+
+set_aom_config_var(CONFIG_MULTITHREAD 1 NUMBER "Multithread support.")
+set_aom_config_var(CONFIG_OS_SUPPORT 0 NUMBER "Internal flag.")
+set_aom_config_var(CONFIG_PIC 0 NUMBER "Build with PIC enabled.")
+set_aom_config_var(CONFIG_RUNTIME_CPU_DETECT 1 NUMBER
+                   "Runtime CPU detection support.")
+set_aom_config_var(CONFIG_SHARED 0 NUMBER "Build shared libs.")
+set_aom_config_var(CONFIG_STATIC 1 NUMBER "Build static libs.")
+set_aom_config_var(CONFIG_WEBM_IO 1 NUMBER "Enables WebM support.")
 
 # Debugging flags.
-set(CONFIG_BITSTREAM_DEBUG 0 CACHE NUMBER "Bitstream debugging flag.")
-set(CONFIG_DEBUG 0 CACHE NUMBER "Debug build flag.")
-set(CONFIG_MISMATCH_DEBUG 0 CACHE NUMBER "Mismatch debugging flag.")
+set_aom_config_var(CONFIG_BITSTREAM_DEBUG 0 NUMBER "Bitstream debugging flag.")
+set_aom_config_var(CONFIG_DEBUG 0 NUMBER "Debug build flag.")
+set_aom_config_var(CONFIG_MISMATCH_DEBUG 0 NUMBER "Mismatch debugging flag.")
 
 # AV1 feature flags.
-set(CONFIG_ACCOUNTING 0 CACHE NUMBER "Enables bit accounting.")
-set(CONFIG_ANALYZER 0 CACHE NUMBER "Enables bit stream analyzer.")
-set(CONFIG_COEFFICIENT_RANGE_CHECKING 0 CACHE NUMBER "Coefficient range check.")
-set(CONFIG_DENOISE 0 CACHE NUMBER "Denoise/noise modeling support in encoder.")
-set(CONFIG_FILEOPTIONS 1 CACHE NUMBER "Enables encoder config file support.")
-set(CONFIG_INSPECTION 0 CACHE NUMBER "Enables bitstream inspection.")
-set(CONFIG_INTERNAL_STATS 0 CACHE NUMBER "Enables internal encoder stats.")
-set(CONFIG_LOWBITDEPTH 0 CACHE NUMBER "Enables 8-bit optimized pipeline.")
-set(CONFIG_SIZE_LIMIT 0 CACHE NUMBER "Limit max decode width/height.")
-set(CONFIG_SPATIAL_RESAMPLING 1 CACHE NUMBER "Spatial resampling.")
-set(DECODE_HEIGHT_LIMIT 0 CACHE NUMBER "Set limit for decode height.")
-set(DECODE_WIDTH_LIMIT 0 CACHE NUMBER "Set limit for decode width.")
+set_aom_config_var(CONFIG_ACCOUNTING 0 NUMBER "Enables bit accounting.")
+set_aom_config_var(CONFIG_ANALYZER 0 NUMBER "Enables bit stream analyzer.")
+set_aom_config_var(CONFIG_COEFFICIENT_RANGE_CHECKING 0 NUMBER
+                   "Coefficient range check.")
+set_aom_config_var(CONFIG_DENOISE 1 NUMBER
+                   "Denoise/noise modeling support in encoder.")
+set_aom_config_var(CONFIG_FILEOPTIONS 1 NUMBER
+                   "Enables encoder config file support.")
+set_aom_config_var(CONFIG_FIX_GF_LENGTH 1 NUMBER
+                   "Fix the GF length if possible")
+set_aom_config_var(CONFIG_INSPECTION 0 NUMBER "Enables bitstream inspection.")
+set_aom_config_var(CONFIG_INTERNAL_STATS 0 NUMBER
+                   "Enables internal encoder stats.")
+set_aom_config_var(CONFIG_LOWBITDEPTH 0 NUMBER
+                   "Enables 8-bit optimized pipeline.")
+set_aom_config_var(CONFIG_MAX_DECODE_PROFILE 2 NUMBER
+                   "Max profile to support decoding.")
+set_aom_config_var(CONFIG_NORMAL_TILE_MODE 0 NUMBER
+                   "Only enables normal tile mode.")
+set_aom_config_var(
+  CONFIG_REDUCED_ENCODER_BORDER 0 NUMBER
+  "Enable reduced border extention for encoder. \
+                    Disables superres and resize support."
+  )
+set_aom_config_var(CONFIG_SIZE_LIMIT 0 NUMBER "Limit max decode width/height.")
+set_aom_config_var(CONFIG_SPATIAL_RESAMPLING 1 NUMBER "Spatial resampling.")
+set_aom_config_var(DECODE_HEIGHT_LIMIT 0 NUMBER "Set limit for decode height.")
+set_aom_config_var(DECODE_WIDTH_LIMIT 0 NUMBER "Set limit for decode width.")
+set_aom_config_var(CONFIG_GLOBAL_MOTION_SEARCH 1 NUMBER
+                   "Global motion search flag.")
 
 # AV1 experiment flags.
-set(CONFIG_COLLECT_INTER_MODE_RD_STATS 1 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_COLLECT_RD_STATS 0 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_DIST_8X8 1 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_ENTROPY_STATS 0 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_FP_MB_STATS 0 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_INTER_STATS_ONLY 0 CACHE NUMBER "AV1 experiment flag.")
-set(CONFIG_RD_DEBUG 0 CACHE NUMBER "AV1 experiment flag.")
+set_aom_config_var(CONFIG_COLLECT_INTER_MODE_RD_STATS 1 NUMBER
+                   "AV1 experiment flag.")
+set_aom_config_var(CONFIG_COLLECT_RD_STATS 0 NUMBER "AV1 experiment flag.")
+set_aom_config_var(CONFIG_DIST_8X8 0 NUMBER "AV1 experiment flag.")
+set_aom_config_var(CONFIG_ENTROPY_STATS 0 NUMBER "AV1 experiment flag.")
+set_aom_config_var(CONFIG_FP_MB_STATS 0 NUMBER "AV1 experiment flag.")
+set_aom_config_var(CONFIG_INTER_STATS_ONLY 0 NUMBER "AV1 experiment flag.")
+set_aom_config_var(CONFIG_RD_DEBUG 0 NUMBER "AV1 experiment flag.")
+set_aom_config_var(CONFIG_2PASS_PARTITION_SEARCH_LVL 1 NUMBER
+                   "AV1 experiment flag.")
+set_aom_config_var(CONFIG_SHARP_SETTINGS 0 NUMBER
+                   "Use sharper encoding settings")
+
+#
+# Variables in this section control optional features of the build system.
+#
+set_aom_option_var(ENABLE_CCACHE "Enable ccache support." OFF)
+set_aom_option_var(ENABLE_DECODE_PERF_TESTS "Enables decoder performance tests"
+                   OFF)
+set_aom_option_var(ENABLE_DISTCC "Enable distcc support." OFF)
+set_aom_option_var(ENABLE_DOCS
+                   "Enable documentation generation (doxygen required)." ON)
+set_aom_option_var(ENABLE_ENCODE_PERF_TESTS "Enables encoder performance tests"
+                   OFF)
+set_aom_option_var(ENABLE_EXAMPLES "Enables build of example code." ON)
+set_aom_option_var(ENABLE_GOMA "Enable goma support." OFF)
+set_aom_option_var(
+  ENABLE_IDE_TEST_HOSTING
+  "Enables running tests within IDEs like Visual Studio and Xcode." OFF)
+set_aom_option_var(ENABLE_NASM "Use nasm instead of yasm for x86 assembly." OFF)
+set_aom_option_var(ENABLE_TESTDATA "Enables unit test data download targets."
+                   ON)
+set_aom_option_var(ENABLE_TESTS "Enables unit tests." ON)
+set_aom_option_var(ENABLE_TOOLS "Enable applications in tools sub directory."
+                   ON)
+set_aom_option_var(ENABLE_WERROR "Converts warnings to errors at compile time."
+                   OFF)
+
+# ARM assembly/intrinsics flags.
+set_aom_option_var(ENABLE_NEON "Enables NEON optimizations on ARM targets." ON)
+
+# MIPS assembly/intrinsics flags.
+set_aom_option_var(ENABLE_DSPR2 "Enables DSPR2 optimizations on MIPS targets."
+                   OFF)
+set_aom_option_var(ENABLE_MSA "Enables MSA optimizations on MIPS targets." OFF)
+
+# VSX intrinsics flags.
+set_aom_option_var(ENABLE_VSX "Enables VSX optimizations on PowerPC targets."
+                   ON)
+
+# x86/x86_64 assembly/intrinsics flags.
+set_aom_option_var(ENABLE_MMX
+                   "Enables MMX optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_SSE
+                   "Enables SSE optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_SSE2
+                   "Enables SSE2 optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_SSE3
+                   "Enables SSE3 optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_SSSE3
+                   "Enables SSSE3 optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_SSE4_1
+                   "Enables SSE4_1 optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_SSE4_2
+                   "Enables SSE4_2 optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_AVX
+                   "Enables AVX optimizations on x86/x86_64 targets." ON)
+set_aom_option_var(ENABLE_AVX2
+                   "Enables AVX2 optimizations on x86/x86_64 targets." ON)
diff --git a/third_party/aom/build/cmake/aom_configure.cmake b/third_party/aom/build/cmake/aom_configure.cmake
index a12389778..c0c7381e8 100644
--- a/third_party/aom/build/cmake/aom_configure.cmake
+++ b/third_party/aom/build/cmake/aom_configure.cmake
@@ -20,19 +20,6 @@ include(FindThreads)
 set(AOM_SUPPORTED_CPU_TARGETS
     "arm64 armv7 armv7s generic mips32 mips64 ppc x86 x86_64")
 
-# Generate the user config settings. This must occur before include of
-# aom_config_defaults.cmake (because it turns every config variable into a cache
-# variable with its own help string).
-get_cmake_property(cmake_cache_vars CACHE_VARIABLES)
-foreach(cache_var ${cmake_cache_vars})
-  get_property(cache_var_helpstring CACHE ${cache_var} PROPERTY HELPSTRING)
-  set(cmdline_helpstring "No help, variable specified on the command line.")
-  if("${cache_var_helpstring}" STREQUAL "${cmdline_helpstring}")
-    set(AOM_CMAKE_CONFIG "${AOM_CMAKE_CONFIG} -D${cache_var}=${${cache_var}}")
-  endif()
-endforeach()
-string(STRIP "${AOM_CMAKE_CONFIG}" AOM_CMAKE_CONFIG)
-
 include("${AOM_ROOT}/build/cmake/aom_config_defaults.cmake")
 include("${AOM_ROOT}/build/cmake/aom_experiment_deps.cmake")
 include("${AOM_ROOT}/build/cmake/aom_optimization.cmake")
@@ -40,6 +27,16 @@ include("${AOM_ROOT}/build/cmake/compiler_flags.cmake")
 include("${AOM_ROOT}/build/cmake/compiler_tests.cmake")
 include("${AOM_ROOT}/build/cmake/util.cmake")
 
+# Generate the user config settings.
+list(APPEND aom_build_vars ${AOM_CONFIG_VARS} ${AOM_OPTION_VARS})
+foreach(cache_var ${aom_build_vars})
+  get_property(cache_var_helpstring CACHE ${cache_var} PROPERTY HELPSTRING)
+  if("${cache_var_helpstring}" STREQUAL "${cmake_cmdline_helpstring}")
+    set(AOM_CMAKE_CONFIG "${AOM_CMAKE_CONFIG} -D${cache_var}=${${cache_var}}")
+  endif()
+endforeach()
+string(STRIP "${AOM_CMAKE_CONFIG}" AOM_CMAKE_CONFIG)
+
 # Detect target CPU.
 if(NOT AOM_TARGET_CPU)
   if("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "AMD64" OR
@@ -73,7 +70,9 @@ if(NOT AOM_TARGET_CPU)
 endif()
 
 if(CMAKE_TOOLCHAIN_FILE) # Add toolchain file to config string.
-  set(toolchain_string "-DCMAKE_TOOLCHAIN_FILE=\\\"${CMAKE_TOOLCHAIN_FILE}\\\"")
+  file(RELATIVE_PATH toolchain_path "${AOM_CONFIG_DIR}"
+                     "${CMAKE_TOOLCHAIN_FILE}")
+  set(toolchain_string "-DCMAKE_TOOLCHAIN_FILE=\\\"${toolchain_path}\\\"")
   set(AOM_CMAKE_CONFIG "${toolchain_string} ${AOM_CMAKE_CONFIG}")
 else()
 
@@ -81,6 +80,8 @@ else()
   set(AOM_CMAKE_CONFIG "-DAOM_TARGET_CPU=${AOM_TARGET_CPU} ${AOM_CMAKE_CONFIG}")
 endif()
 set(AOM_CMAKE_CONFIG "-G \\\"${CMAKE_GENERATOR}\\\" ${AOM_CMAKE_CONFIG}")
+file(RELATIVE_PATH source_path "${AOM_CONFIG_DIR}" "${AOM_ROOT}")
+set(AOM_CMAKE_CONFIG "cmake ${source_path} ${AOM_CMAKE_CONFIG}")
 string(STRIP "${AOM_CMAKE_CONFIG}" AOM_CMAKE_CONFIG)
 
 message("--- aom_configure: Detected CPU: ${AOM_TARGET_CPU}")
@@ -90,13 +91,13 @@ if("${CMAKE_BUILD_TYPE}" MATCHES "Deb")
   set(CONFIG_DEBUG 1)
 endif()
 
-if(NOT MSVC)
-  if(BUILD_SHARED_LIBS)
-    set(CONFIG_PIC 1)
-    set(CONFIG_SHARED 1)
-    set(CONFIG_STATIC 0)
-  endif()
+if(BUILD_SHARED_LIBS)
+  set(CONFIG_PIC 1)
+  set(CONFIG_SHARED 1)
+  set(CONFIG_STATIC 0)
+endif()
 
+if(NOT MSVC)
   if(CONFIG_PIC)
 
     # TODO(tomfinegan): clang needs -pie in CMAKE_EXE_LINKER_FLAGS for this to
@@ -109,8 +110,6 @@ if(NOT MSVC)
       set(AOM_AS_FLAGS ${AOM_AS_FLAGS} -DPIC)
     endif()
   endif()
-else()
-  set(CONFIG_MSVS 1)
 endif()
 
 if(NOT "${AOM_SUPPORTED_CPU_TARGETS}" MATCHES "${AOM_TARGET_CPU}")
@@ -261,13 +260,15 @@ else()
   add_compiler_flag_if_supported("-Wlogical-op")
   add_compiler_flag_if_supported("-Wpointer-arith")
   add_compiler_flag_if_supported("-Wsign-compare")
-  add_compiler_flag_if_supported("-Wstack-usage=360000")
   add_compiler_flag_if_supported("-Wstring-conversion")
   add_compiler_flag_if_supported("-Wtype-limits")
   add_compiler_flag_if_supported("-Wuninitialized")
   add_compiler_flag_if_supported("-Wunused")
   add_compiler_flag_if_supported("-Wvla")
 
+  add_c_flag_if_supported("-Wstack-usage=100000")
+  add_cxx_flag_if_supported("-Wstack-usage=360000")
+
   # TODO(jzern): this could be added as a cxx flags for test/*.cc only, avoiding
   # third_party.
   add_c_flag_if_supported("-Wshorten-64-to-32")
@@ -278,6 +279,12 @@ else()
   # Add -Wundef only for C files to avoid massive gtest warning spam.
   add_c_flag_if_supported("-Wundef")
 
+  # Quiet gcc 6 vs 7 abi warnings:
+  # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77728
+  if("${AOM_TARGET_CPU}" MATCHES "arm")
+    add_cxx_flag_if_supported("-Wno-psabi")
+  endif()
+
   if(ENABLE_WERROR)
     add_compiler_flag_if_supported("-Werror")
   endif()
@@ -344,7 +351,7 @@ foreach(NUM RANGE ${AOM_RTCD_CUSTOM_COMMAND_COUNT})
   list(GET AOM_RTCD_HEADER_FILE_LIST ${NUM} AOM_RTCD_HEADER_FILE)
   list(GET AOM_RTCD_SOURCE_FILE_LIST ${NUM} AOM_RTCD_SOURCE_FILE)
   list(GET AOM_RTCD_SYMBOL_LIST ${NUM} AOM_RTCD_SYMBOL)
-  execute_process(COMMAND ${PERL_EXECUTABLE} "${AOM_ROOT}/build/make/rtcd.pl"
+  execute_process(COMMAND ${PERL_EXECUTABLE} "${AOM_ROOT}/build/cmake/rtcd.pl"
                           --arch=${AOM_TARGET_CPU}
                           --sym=${AOM_RTCD_SYMBOL} ${AOM_RTCD_FLAGS}
                           --config=${AOM_CONFIG_DIR}/config/aom_config.h
diff --git a/third_party/aom/build/cmake/aom_experiment_deps.cmake b/third_party/aom/build/cmake/aom_experiment_deps.cmake
index e2c8102aa..0688704e5 100644
--- a/third_party/aom/build/cmake/aom_experiment_deps.cmake
+++ b/third_party/aom/build/cmake/aom_experiment_deps.cmake
@@ -25,4 +25,8 @@ macro(fix_experiment_configs)
     change_config_and_warn(CONFIG_RD_DEBUG 0 CONFIG_JNT_COMP)
   endif()
 
+  if(CONFIG_DIST_8X8 AND CONFIG_MULTITHREAD)
+    change_config_and_warn(CONFIG_DIST_8X8 0 CONFIG_MULTITHREAD)
+  endif()
+
 endmacro()
diff --git a/third_party/aom/build/cmake/aom_optimization.cmake b/third_party/aom/build/cmake/aom_optimization.cmake
index ce3dc0340..be32a3212 100644
--- a/third_party/aom/build/cmake/aom_optimization.cmake
+++ b/third_party/aom/build/cmake/aom_optimization.cmake
@@ -193,13 +193,13 @@ function(test_nasm)
 endfunction()
 
 # Adds build command for generation of rtcd C source files using
-# build/make/rtcd.pl. $config is the input perl file, $output is the output C
+# build/cmake/rtcd.pl. $config is the input perl file, $output is the output C
 # include file, $source is the C source file, and $symbol is used for the symbol
 # argument passed to rtcd.pl.
 function(add_rtcd_build_step config output source symbol)
   add_custom_command(OUTPUT ${output}
                      COMMAND ${PERL_EXECUTABLE} ARGS
-                             "${AOM_ROOT}/build/make/rtcd.pl"
+                             "${AOM_ROOT}/build/cmake/rtcd.pl"
                              --arch=${AOM_TARGET_CPU}
                              --sym=${symbol} ${AOM_RTCD_FLAGS}
                              --config=${AOM_CONFIG_DIR}/config/aom_config.h
diff --git a/third_party/aom/build/cmake/exports.cmake b/third_party/aom/build/cmake/exports.cmake
index 5abfc9a5f..e0813dc0f 100644
--- a/third_party/aom/build/cmake/exports.cmake
+++ b/third_party/aom/build/cmake/exports.cmake
@@ -34,7 +34,8 @@ function(setup_exports_target)
                             -DAOM_SYM_FILE="${aom_sym_file}" -DAOM_MSVC=${MSVC}
                             -DAOM_XCODE=${XCODE} -DCONFIG_NAME=$<CONFIG>
                             -DCONFIG_AV1_DECODER=${CONFIG_AV1_DECODER}
-                            -DCONFIG_AV1_ENCODER=${CONFIG_AV1_ENCODER} -P
+                            -DCONFIG_AV1_ENCODER=${CONFIG_AV1_ENCODER}
+                            -DENABLE_TESTS=${ENABLE_TESTS} -P
                             "${AOM_ROOT}/build/cmake/generate_exports.cmake"
                     SOURCES ${AOM_EXPORTS_SOURCES}
                     DEPENDS ${AOM_EXPORTS_SOURCES})
@@ -47,10 +48,12 @@ function(setup_exports_target)
     set_property(TARGET aom APPEND_STRING
                  PROPERTY LINK_FLAGS "-exported_symbols_list ${aom_sym_file}")
   elseif(WIN32)
-    message(FATAL_ERROR "Windows DLL builds not supported yet.")
     if(NOT MSVC)
       set_property(TARGET aom APPEND_STRING
                    PROPERTY LINK_FLAGS "-Wl,--version-script ${aom_sym_file}")
+    else()
+      set_property(TARGET aom APPEND_STRING
+                   PROPERTY LINK_FLAGS "/DEF:${aom_sym_file}")
     endif()
 
     # TODO(tomfinegan): Sort out the import lib situation and flags for MSVC.
diff --git a/third_party/aom/build/cmake/exports_sources.cmake b/third_party/aom/build/cmake/exports_sources.cmake
index 48790dbaa..576920e36 100644
--- a/third_party/aom/build/cmake/exports_sources.cmake
+++ b/third_party/aom/build/cmake/exports_sources.cmake
@@ -13,14 +13,20 @@ if(AOM_BUILD_CMAKE_EXPORTS_SOURCES_CMAKE_)
 endif() # AOM_BUILD_CMAKE_EXPORTS_SOURCES_CMAKE_
 set(AOM_BUILD_CMAKE_EXPORTS_SOURCES_CMAKE_ 1)
 
-set(AOM_EXPORTS_SOURCES "${AOM_ROOT}/aom/exports_com")
+list(APPEND AOM_EXPORTS_SOURCES "${AOM_ROOT}/aom/exports_com"
+            "${AOM_ROOT}/av1/exports_com")
 
 if(CONFIG_AV1_DECODER)
-  set(AOM_EXPORTS_SOURCES ${AOM_EXPORTS_SOURCES} "${AOM_ROOT}/aom/exports_dec"
-      "${AOM_ROOT}/av1/exports_dec")
+  list(APPEND AOM_EXPORTS_SOURCES "${AOM_ROOT}/aom/exports_dec"
+              "${AOM_ROOT}/av1/exports_dec")
 endif()
 
 if(CONFIG_AV1_ENCODER)
-  set(AOM_EXPORTS_SOURCES ${AOM_EXPORTS_SOURCES} "${AOM_ROOT}/aom/exports_enc"
-      "${AOM_ROOT}/av1/exports_enc")
+  list(APPEND AOM_EXPORTS_SOURCES "${AOM_ROOT}/aom/exports_enc"
+              "${AOM_ROOT}/av1/exports_enc")
+endif()
+
+if(ENABLE_TESTS)
+  list(APPEND AOM_EXPORTS_SOURCES "${AOM_ROOT}/aom/exports_test"
+              "${AOM_ROOT}/av1/exports_test")
 endif()
diff --git a/third_party/aom/build/cmake/generate_aom_config_templates.cmake b/third_party/aom/build/cmake/generate_aom_config_templates.cmake
index 8fbb4737b..b91c036de 100644
--- a/third_party/aom/build/cmake/generate_aom_config_templates.cmake
+++ b/third_party/aom/build/cmake/generate_aom_config_templates.cmake
@@ -78,23 +78,24 @@ if(NOT EXISTS "${AOM_DEFAULTS}")
 endif()
 
 include("${AOM_ROOT}/build/cmake/aom_config_defaults.cmake")
-get_cmake_property(cmake_cache_vars CACHE_VARIABLES)
+list(APPEND aom_build_vars ${AOM_DETECT_VARS} ${AOM_CONFIG_VARS})
+list(SORT aom_build_vars)
 
 set(aom_config_h_template "${AOM_CONFIG_DIR}/config/aom_config.h.cmake")
 file(WRITE "${aom_config_h_template}" ${h_file_header_block})
-foreach(cache_var ${cmake_cache_vars})
-  if(NOT "${cache_var}" MATCHES "AOM_CONFIG_DIR\|AOM_ROOT\|^CMAKE_")
+foreach(aom_var ${aom_build_vars})
+  if(NOT "${aom_var}" STREQUAL "AOM_RTCD_FLAGS")
     file(APPEND "${aom_config_h_template}"
-                "\#define ${cache_var} \${${cache_var}}\n")
+                "\#define ${aom_var} \${${aom_var}}\n")
   endif()
 endforeach()
-file(APPEND "${aom_config_h_template}" "\#endif  /* AOM_CONFIG_H_ */")
+file(APPEND "${aom_config_h_template}" "\#endif  // AOM_CONFIG_H_")
 
 set(aom_asm_config_template "${AOM_CONFIG_DIR}/config/aom_config.asm.cmake")
 file(WRITE "${aom_asm_config_template}" ${asm_file_header_block})
-foreach(cache_var ${cmake_cache_vars})
-  if(NOT "${cache_var}" MATCHES "AOM_CONFIG_DIR\|AOM_ROOT\|^CMAKE_\|INLINE")
-    file(APPEND "${aom_asm_config_template}"
-                "${cache_var} equ \${${cache_var}}\n")
+foreach(aom_var ${aom_build_vars})
+  if(NOT "${aom_var}" STREQUAL "INLINE" AND NOT "${aom_var}" STREQUAL
+     "AOM_RTCD_FLAGS")
+    file(APPEND "${aom_asm_config_template}" "${aom_var} equ \${${aom_var}}\n")
   endif()
 endforeach()
diff --git a/third_party/aom/build/cmake/generate_exports.cmake b/third_party/aom/build/cmake/generate_exports.cmake
index 4dce3a671..7ab5aaef8 100644
--- a/third_party/aom/build/cmake/generate_exports.cmake
+++ b/third_party/aom/build/cmake/generate_exports.cmake
@@ -24,9 +24,7 @@ include("${AOM_ROOT}/build/cmake/exports_sources.cmake")
 if("${AOM_TARGET_SYSTEM}" STREQUAL "Darwin")
   set(symbol_prefix "_")
 elseif("${AOM_TARGET_SYSTEM}" MATCHES "Windows\|MSYS" AND AOM_MSVC)
-  set(symbol_prefix "_")
-  file(WRITE "${AOM_SYM_FILE}" "LIBRARY libaom INITINSTANCE TERMINSTANCE\n"
-             "DATA MULTIPLE NONSHARED\n" "EXPORTS\n")
+  file(WRITE "${AOM_SYM_FILE}" "LIBRARY aom\n" "EXPORTS\n")
 else()
   set(symbol_suffix ";")
 endif()
@@ -35,11 +33,10 @@ set(aom_sym_file "${AOM_SYM_FILE}")
 
 if("${AOM_TARGET_SYSTEM}" STREQUAL "Darwin")
   file(REMOVE "${aom_sym_file}")
-elseif("${AOM_TARGET_SYSTEM}" MATCHES "Windows\|MSYS")
-  file(WRITE "${aom_sym_file}" "LIBRARY libaom INITINSTANCE TERMINSTANCE\n"
-             "DATA MULTIPLE NONSHARED\n" "EXPORTS\n")
+elseif("${AOM_TARGET_SYSTEM}" MATCHES "Windows\|MSYS" AND AOM_MSVC)
+  file(WRITE "${aom_sym_file}" "LIBRARY aom\n" "EXPORTS\n")
 else()
-  file(WRITE "${aom_sym_file}" "{ global:\n")
+  file(WRITE "${aom_sym_file}" "{\nglobal:\n")
 endif()
 
 foreach(export_file ${AOM_EXPORTS_SOURCES})
@@ -50,11 +47,20 @@ endforeach()
 
 foreach(exported_symbol ${exported_symbols})
   string(STRIP "${exported_symbol}" exported_symbol)
+  if("${AOM_TARGET_SYSTEM}" MATCHES "Windows\|MSYS" AND AOM_MSVC)
+    string(SUBSTRING ${exported_symbol} 0 4 export_type)
+    string(COMPARE EQUAL "${export_type}" "data" is_data)
+    if(is_data)
+      set(symbol_suffix " DATA")
+    else()
+      set(symbol_suffix "")
+    endif()
+  endif()
   string(REGEX REPLACE "text \|data " "" "exported_symbol" "${exported_symbol}")
-  set(exported_symbol "${symbol_prefix}${exported_symbol}${symbol_suffix}")
+  set(exported_symbol "  ${symbol_prefix}${exported_symbol}${symbol_suffix}")
   file(APPEND "${aom_sym_file}" "${exported_symbol}\n")
 endforeach()
 
 if("${aom_sym_file}" MATCHES "ver$")
-  file(APPEND "${aom_sym_file}" " };")
+  file(APPEND "${aom_sym_file}" " \nlocal:\n  *;\n};")
 endif()
diff --git a/third_party/aom/build/cmake/ios-Info.plist b/third_party/aom/build/cmake/ios-Info.plist
new file mode 100644
index 000000000..300e3e310
--- /dev/null
+++ b/third_party/aom/build/cmake/ios-Info.plist
@@ -0,0 +1,37 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>en</string>
+	<key>CFBundleExecutable</key>
+	<string>AOM</string>
+	<key>CFBundleIdentifier</key>
+	<string>org.webmproject.AOM</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>AOM</string>
+	<key>CFBundlePackageType</key>
+	<string>FMWK</string>
+	<key>CFBundleShortVersionString</key>
+	<string>${VERSION}</string>
+	<key>CFBundleSignature</key>
+	<string>????</string>
+	<key>CFBundleSupportedPlatforms</key>
+	<array>
+		<string>iPhoneOS</string>
+	</array>
+	<key>CFBundleVersion</key>
+	<string>${VERSION}</string>
+	<key>MinimumOSVersion</key>
+	<string>${IOS_VERSION_MIN}</string>
+	<key>UIDeviceFamily</key>
+	<array>
+		<integer>1</integer>
+		<integer>2</integer>
+	</array>
+	<key>AOMFullVersion</key>
+	<string>${FULLVERSION}</string>
+</dict>
+</plist>
diff --git a/third_party/aom/build/cmake/iosbuild.sh b/third_party/aom/build/cmake/iosbuild.sh
new file mode 100755
index 000000000..167ece200
--- /dev/null
+++ b/third_party/aom/build/cmake/iosbuild.sh
@@ -0,0 +1,384 @@
+#!/bin/sh
+## Copyright (c) 2016, Alliance for Open Media. All rights reserved
+##
+## This source code is subject to the terms of the BSD 2 Clause License and
+## the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+## was not distributed with this source code in the LICENSE file, you can
+## obtain it at www.aomedia.org/license/software. If the Alliance for Open
+## Media Patent License 1.0 was not distributed with this source code in the
+## PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+##
+## This script generates 'AOM.framework'. An iOS app can encode and decode AVx
+## video by including 'AOM.framework'.
+##
+## Run iosbuild.sh to create 'AOM.framework' in the current directory.
+##
+set -e
+devnull='> /dev/null 2>&1'
+
+BUILD_ROOT="_iosbuild"
+CONFIGURE_ARGS="--disable-docs
+                --disable-examples
+                --disable-libyuv
+                --disable-unit-tests"
+DIST_DIR="_dist"
+FRAMEWORK_DIR="AOM.framework"
+FRAMEWORK_LIB="AOM.framework/AOM"
+HEADER_DIR="${FRAMEWORK_DIR}/Headers/aom"
+SCRIPT_DIR=$(dirname "$0")
+LIBAOM_SOURCE_DIR=$(cd ${SCRIPT_DIR}/../..; pwd)
+LIPO=$(xcrun -sdk iphoneos${SDK} -find lipo)
+ORIG_PWD="$(pwd)"
+ARM_TARGETS="arm64-darwin-gcc
+             armv7-darwin-gcc
+             armv7s-darwin-gcc"
+SIM_TARGETS="x86-iphonesimulator-gcc
+             x86_64-iphonesimulator-gcc"
+OSX_TARGETS="x86-darwin16-gcc
+             x86_64-darwin16-gcc"
+TARGETS="${ARM_TARGETS} ${SIM_TARGETS}"
+
+# Configures for the target specified by $1, and invokes make with the dist
+# target using $ as the distribution output directory.
+build_target() {
+  local target="$1"
+  local old_pwd="$(pwd)"
+  local target_specific_flags=""
+
+  vlog "***Building target: ${target}***"
+
+  case "${target}" in
+    x86-*)
+      target_specific_flags="--enable-pic"
+      vlog "Enabled PIC for ${target}"
+      ;;
+  esac
+
+  mkdir "${target}"
+  cd "${target}"
+  # TODO(tomfinegan@google.com): switch to cmake.
+  eval "${LIBAOM_SOURCE_DIR}/configure" --target="${target}" \
+    ${CONFIGURE_ARGS} ${EXTRA_CONFIGURE_ARGS} ${target_specific_flags} \
+    ${devnull}
+  export DIST_DIR
+  eval make dist ${devnull}
+  cd "${old_pwd}"
+
+  vlog "***Done building target: ${target}***"
+}
+
+# Returns the preprocessor symbol for the target specified by $1.
+target_to_preproc_symbol() {
+  target="$1"
+  case "${target}" in
+    arm64-*)
+      echo "__aarch64__"
+      ;;
+    armv7-*)
+      echo "__ARM_ARCH_7A__"
+      ;;
+    armv7s-*)
+      echo "__ARM_ARCH_7S__"
+      ;;
+    x86-*)
+      echo "__i386__"
+      ;;
+    x86_64-*)
+      echo "__x86_64__"
+      ;;
+    *)
+      echo "#error ${target} unknown/unsupported"
+      return 1
+      ;;
+  esac
+}
+
+# Create a aom_config.h shim that, based on preprocessor settings for the
+# current target CPU, includes the real aom_config.h for the current target.
+# $1 is the list of targets.
+create_aom_framework_config_shim() {
+  local targets="$1"
+  local config_file="${HEADER_DIR}/aom_config.h"
+  local preproc_symbol=""
+  local target=""
+  local include_guard="AOM_FRAMEWORK_HEADERS_AOM_AOM_CONFIG_H_"
+
+  local file_header="/*
+ *  Copyright (c) $(date +%Y), Alliance for Open Media. All rights reserved.
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+/* GENERATED FILE: DO NOT EDIT! */
+
+#ifndef ${include_guard}
+#define ${include_guard}
+
+#if defined"
+
+  printf "%s" "${file_header}" > "${config_file}"
+  for target in ${targets}; do
+    preproc_symbol=$(target_to_preproc_symbol "${target}")
+    printf " ${preproc_symbol}\n" >> "${config_file}"
+    printf "#define AOM_FRAMEWORK_TARGET \"${target}\"\n" >> "${config_file}"
+    printf "#include \"AOM/aom/${target}/aom_config.h\"\n" >> "${config_file}"
+    printf "#elif defined" >> "${config_file}"
+    mkdir "${HEADER_DIR}/${target}"
+    cp -p "${BUILD_ROOT}/${target}/aom_config.h" "${HEADER_DIR}/${target}"
+  done
+
+  # Consume the last line of output from the loop: We don't want it.
+  sed -i '' -e '$d' "${config_file}"
+
+  printf "#endif\n\n" >> "${config_file}"
+  printf "#endif  // ${include_guard}" >> "${config_file}"
+}
+
+# Verifies that $FRAMEWORK_LIB fat library contains requested builds.
+verify_framework_targets() {
+  local requested_cpus=""
+  local cpu=""
+
+  # Extract CPU from full target name.
+  for target; do
+    cpu="${target%%-*}"
+    if [ "${cpu}" = "x86" ]; then
+      # lipo -info outputs i386 for libaom x86 targets.
+      cpu="i386"
+    fi
+    requested_cpus="${requested_cpus}${cpu} "
+  done
+
+  # Get target CPUs present in framework library.
+  local targets_built=$(${LIPO} -info ${FRAMEWORK_LIB})
+
+  # $LIPO -info outputs a string like the following:
+  #   Architectures in the fat file: $FRAMEWORK_LIB <architectures>
+  # Capture only the architecture strings.
+  targets_built=${targets_built##*: }
+
+  # Sort CPU strings to make the next step a simple string compare.
+  local actual=$(echo ${targets_built} | tr " " "\n" | sort | tr "\n" " ")
+  local requested=$(echo ${requested_cpus} | tr " " "\n" | sort | tr "\n" " ")
+
+  vlog "Requested ${FRAMEWORK_LIB} CPUs: ${requested}"
+  vlog "Actual ${FRAMEWORK_LIB} CPUs: ${actual}"
+
+  if [ "${requested}" != "${actual}" ]; then
+    elog "Actual ${FRAMEWORK_LIB} targets do not match requested target list."
+    elog "  Requested target CPUs: ${requested}"
+    elog "  Actual target CPUs: ${actual}"
+    return 1
+  fi
+}
+
+# Configures and builds each target specified by $1, and then builds
+# AOM.framework.
+build_framework() {
+  local lib_list=""
+  local targets="$1"
+  local target=""
+  local target_dist_dir=""
+
+  # Clean up from previous build(s).
+  rm -rf "${BUILD_ROOT}" "${FRAMEWORK_DIR}"
+
+  # Create output dirs.
+  mkdir -p "${BUILD_ROOT}"
+  mkdir -p "${HEADER_DIR}"
+
+  cd "${BUILD_ROOT}"
+
+  for target in ${targets}; do
+    build_target "${target}"
+    target_dist_dir="${BUILD_ROOT}/${target}/${DIST_DIR}"
+    if [ "${ENABLE_SHARED}" = "yes" ]; then
+      local suffix="dylib"
+    else
+      local suffix="a"
+    fi
+    lib_list="${lib_list} ${target_dist_dir}/lib/libaom.${suffix}"
+  done
+
+  cd "${ORIG_PWD}"
+
+  # The basic libaom API includes are all the same; just grab the most recent
+  # set.
+  cp -p "${target_dist_dir}"/include/aom/* "${HEADER_DIR}"
+
+  # Build the fat library.
+  ${LIPO} -create ${lib_list} -output ${FRAMEWORK_DIR}/AOM
+
+  # Create the aom_config.h shim that allows usage of aom_config.h from
+  # within AOM.framework.
+  create_aom_framework_config_shim "${targets}"
+
+  # Copy in aom_version.h.
+  cp -p "${BUILD_ROOT}/${target}/aom_version.h" "${HEADER_DIR}"
+
+  if [ "${ENABLE_SHARED}" = "yes" ]; then
+    # Adjust the dylib's name so dynamic linking in apps works as expected.
+    install_name_tool -id '@rpath/AOM.framework/AOM' ${FRAMEWORK_DIR}/AOM
+
+    # Copy in Info.plist.
+    cat "${SCRIPT_DIR}/ios-Info.plist" \
+      | sed "s/\${FULLVERSION}/${FULLVERSION}/g" \
+      | sed "s/\${VERSION}/${VERSION}/g" \
+      | sed "s/\${IOS_VERSION_MIN}/${IOS_VERSION_MIN}/g" \
+      > "${FRAMEWORK_DIR}/Info.plist"
+  fi
+
+  # Confirm AOM.framework/AOM contains the targets requested.
+  verify_framework_targets ${targets}
+
+  vlog "Created fat library ${FRAMEWORK_LIB} containing:"
+  for lib in ${lib_list}; do
+    vlog "  $(echo ${lib} | awk -F / '{print $2, $NF}')"
+  done
+}
+
+# Trap function. Cleans up the subtree used to build all targets contained in
+# $TARGETS.
+cleanup() {
+  local res=$?
+  cd "${ORIG_PWD}"
+
+  if [ $res -ne 0 ]; then
+    elog "build exited with error ($res)"
+  fi
+
+  if [ "${PRESERVE_BUILD_OUTPUT}" != "yes" ]; then
+    rm -rf "${BUILD_ROOT}"
+  fi
+}
+
+print_list() {
+  local indent="$1"
+  shift
+  local list="$@"
+  for entry in ${list}; do
+    echo "${indent}${entry}"
+  done
+}
+
+iosbuild_usage() {
+cat << EOF
+  Usage: ${0##*/} [arguments]
+    --help: Display this message and exit.
+    --enable-shared: Build a dynamic framework for use on iOS 8 or later.
+    --extra-configure-args <args>: Extra args to pass when configuring libaom.
+    --macosx: Uses darwin16 targets instead of iphonesimulator targets for x86
+              and x86_64. Allows linking to framework when builds target MacOSX
+              instead of iOS.
+    --preserve-build-output: Do not delete the build directory.
+    --show-build-output: Show output from each library build.
+    --targets <targets>: Override default target list. Defaults:
+$(print_list "        " ${TARGETS})
+    --test-link: Confirms all targets can be linked. Functionally identical to
+                 passing --enable-examples via --extra-configure-args.
+    --verbose: Output information about the environment and each stage of the
+               build.
+EOF
+}
+
+elog() {
+  echo "${0##*/} failed because: $@" 1>&2
+}
+
+vlog() {
+  if [ "${VERBOSE}" = "yes" ]; then
+    echo "$@"
+  fi
+}
+
+trap cleanup EXIT
+
+# Parse the command line.
+while [ -n "$1" ]; do
+  case "$1" in
+    --extra-configure-args)
+      EXTRA_CONFIGURE_ARGS="$2"
+      shift
+      ;;
+    --help)
+      iosbuild_usage
+      exit
+      ;;
+    --enable-shared)
+      ENABLE_SHARED=yes
+      ;;
+    --preserve-build-output)
+      PRESERVE_BUILD_OUTPUT=yes
+      ;;
+    --show-build-output)
+      devnull=
+      ;;
+    --test-link)
+      EXTRA_CONFIGURE_ARGS="${EXTRA_CONFIGURE_ARGS} --enable-examples"
+      ;;
+    --targets)
+      TARGETS="$2"
+      shift
+      ;;
+    --macosx)
+      TARGETS="${ARM_TARGETS} ${OSX_TARGETS}"
+      ;;
+    --verbose)
+      VERBOSE=yes
+      ;;
+    *)
+      iosbuild_usage
+      exit 1
+      ;;
+  esac
+  shift
+done
+
+if [ "${ENABLE_SHARED}" = "yes" ]; then
+  CONFIGURE_ARGS="--enable-shared ${CONFIGURE_ARGS}"
+fi
+
+FULLVERSION=$("${SCRIPT_DIR}"/version.sh --bare "${LIBAOM_SOURCE_DIR}")
+VERSION=$(echo "${FULLVERSION}" | sed -E 's/^v([0-9]+\.[0-9]+\.[0-9]+).*$/\1/')
+
+if [ "$ENABLE_SHARED" = "yes" ]; then
+  IOS_VERSION_OPTIONS="--enable-shared"
+  IOS_VERSION_MIN="8.0"
+else
+  IOS_VERSION_OPTIONS=""
+  IOS_VERSION_MIN="6.0"
+fi
+
+if [ "${VERBOSE}" = "yes" ]; then
+cat << EOF
+  BUILD_ROOT=${BUILD_ROOT}
+  DIST_DIR=${DIST_DIR}
+  CONFIGURE_ARGS=${CONFIGURE_ARGS}
+  EXTRA_CONFIGURE_ARGS=${EXTRA_CONFIGURE_ARGS}
+  FRAMEWORK_DIR=${FRAMEWORK_DIR}
+  FRAMEWORK_LIB=${FRAMEWORK_LIB}
+  HEADER_DIR=${HEADER_DIR}
+  LIBAOM_SOURCE_DIR=${LIBAOM_SOURCE_DIR}
+  LIPO=${LIPO}
+  MAKEFLAGS=${MAKEFLAGS}
+  ORIG_PWD=${ORIG_PWD}
+  PRESERVE_BUILD_OUTPUT=${PRESERVE_BUILD_OUTPUT}
+  TARGETS="$(print_list "" ${TARGETS})"
+  ENABLE_SHARED=${ENABLE_SHARED}
+  OSX_TARGETS="${OSX_TARGETS}"
+  SIM_TARGETS="${SIM_TARGETS}"
+  SCRIPT_DIR="${SCRIPT_DIR}"
+  FULLVERSION="${FULLVERSION}"
+  VERSION="${VERSION}"
+  IOS_VERSION_MIN="${IOS_VERSION_MIN}"
+EOF
+fi
+
+build_framework "${TARGETS}"
+echo "Successfully built '${FRAMEWORK_DIR}' for:"
+print_list "" ${TARGETS}
diff --git a/third_party/aom/build/cmake/rtcd.pl b/third_party/aom/build/cmake/rtcd.pl
new file mode 100755
index 000000000..46e06907c
--- /dev/null
+++ b/third_party/aom/build/cmake/rtcd.pl
@@ -0,0 +1,467 @@
+#!/usr/bin/env perl
+##
+## Copyright (c) 2017, Alliance for Open Media. All rights reserved
+##
+## This source code is subject to the terms of the BSD 2 Clause License and
+## the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+## was not distributed with this source code in the LICENSE file, you can
+## obtain it at www.aomedia.org/license/software. If the Alliance for Open
+## Media Patent License 1.0 was not distributed with this source code in the
+## PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+##
+no strict 'refs';
+use warnings;
+use Getopt::Long;
+Getopt::Long::Configure("auto_help") if $Getopt::Long::VERSION > 2.32;
+
+my %ALL_FUNCS = ();
+my @ALL_ARCHS;
+my @ALL_FORWARD_DECLS;
+my @REQUIRES;
+
+my %opts = ();
+my %disabled = ();
+my %required = ();
+
+my @argv;
+foreach (@ARGV) {
+  $disabled{$1} = 1, next if /--disable-(.*)/;
+  $required{$1} = 1, next if /--require-(.*)/;
+  push @argv, $_;
+}
+
+# NB: use GetOptions() instead of GetOptionsFromArray() for compatibility.
+@ARGV = @argv;
+GetOptions(
+  \%opts,
+  'arch=s',
+  'sym=s',
+  'config=s',
+);
+
+foreach my $opt (qw/arch config/) {
+  if (!defined($opts{$opt})) {
+    warn "--$opt is required!\n";
+    Getopt::Long::HelpMessage('-exit' => 1);
+  }
+}
+
+foreach my $defs_file (@ARGV) {
+  if (!-f $defs_file) {
+    warn "$defs_file: $!\n";
+    Getopt::Long::HelpMessage('-exit' => 1);
+  }
+}
+
+open CONFIG_FILE, $opts{config} or
+  die "Error opening config file '$opts{config}': $!\n";
+
+my %config = ();
+while (<CONFIG_FILE>) {
+  next if !/^#define\s+(?:CONFIG_|HAVE_)/;
+  chomp;
+  my @line_components = split /\s/;
+  scalar @line_components > 2 or
+    die "Invalid input passed to rtcd.pl via $opts{config}.";
+  # $line_components[0] = #define
+  # $line_components[1] = flag name (CONFIG_SOMETHING or HAVE_SOMETHING)
+  # $line_components[2] = flag value (0 or 1)
+  $config{$line_components[1]} = "$line_components[2]" eq "1" ? "yes" : "";
+}
+close CONFIG_FILE;
+
+#
+# Routines for the RTCD DSL to call
+#
+sub aom_config($) {
+  return (defined $config{$_[0]}) ? $config{$_[0]} : "";
+}
+
+sub specialize {
+  if (@_ <= 1) {
+    die "'specialize' must be called with a function name and at least one ",
+        "architecture ('C' is implied): \n@_\n";
+  }
+  my $fn=$_[0];
+  shift;
+  foreach my $opt (@_) {
+    eval "\$${fn}_${opt}=${fn}_${opt}";
+  }
+}
+
+sub add_proto {
+  my $fn = splice(@_, -2, 1);
+  $ALL_FUNCS{$fn} = \@_;
+  specialize $fn, "c";
+}
+
+sub require {
+  foreach my $fn (keys %ALL_FUNCS) {
+    foreach my $opt (@_) {
+      my $ofn = eval "\$${fn}_${opt}";
+      next if !$ofn;
+
+      # if we already have a default, then we can disable it, as we know
+      # we can do better.
+      my $best = eval "\$${fn}_default";
+      if ($best) {
+        my $best_ofn = eval "\$${best}";
+        if ($best_ofn && "$best_ofn" ne "$ofn") {
+          eval "\$${best}_link = 'false'";
+        }
+      }
+      eval "\$${fn}_default=${fn}_${opt}";
+      eval "\$${fn}_${opt}_link='true'";
+    }
+  }
+}
+
+sub forward_decls {
+  push @ALL_FORWARD_DECLS, @_;
+}
+
+#
+# Include the user's directives
+#
+foreach my $f (@ARGV) {
+  open FILE, "<", $f or die "cannot open $f: $!\n";
+  my $contents = join('', <FILE>);
+  close FILE;
+  eval $contents or warn "eval failed: $@\n";
+}
+
+#
+# Process the directives according to the command line
+#
+sub process_forward_decls() {
+  foreach (@ALL_FORWARD_DECLS) {
+    $_->();
+  }
+}
+
+sub determine_indirection {
+  aom_config("CONFIG_RUNTIME_CPU_DETECT") eq "yes" or &require(@ALL_ARCHS);
+  foreach my $fn (keys %ALL_FUNCS) {
+    my $n = "";
+    my @val = @{$ALL_FUNCS{$fn}};
+    my $args = pop @val;
+    my $rtyp = "@val";
+    my $dfn = eval "\$${fn}_default";
+    $dfn = eval "\$${dfn}";
+    foreach my $opt (@_) {
+      my $ofn = eval "\$${fn}_${opt}";
+      next if !$ofn;
+      my $link = eval "\$${fn}_${opt}_link";
+      next if $link && $link eq "false";
+      $n .= "x";
+    }
+    if ($n eq "x") {
+      eval "\$${fn}_indirect = 'false'";
+    } else {
+      eval "\$${fn}_indirect = 'true'";
+    }
+  }
+}
+
+sub declare_function_pointers {
+  foreach my $fn (sort keys %ALL_FUNCS) {
+    my @val = @{$ALL_FUNCS{$fn}};
+    my $args = pop @val;
+    my $rtyp = "@val";
+    my $dfn = eval "\$${fn}_default";
+    $dfn = eval "\$${dfn}";
+    foreach my $opt (@_) {
+      my $ofn = eval "\$${fn}_${opt}";
+      next if !$ofn;
+      print "$rtyp ${ofn}($args);\n";
+    }
+    if (eval "\$${fn}_indirect" eq "false") {
+      print "#define ${fn} ${dfn}\n";
+    } else {
+      print "RTCD_EXTERN $rtyp (*${fn})($args);\n";
+    }
+    print "\n";
+  }
+}
+
+sub set_function_pointers {
+  foreach my $fn (sort keys %ALL_FUNCS) {
+    my @val = @{$ALL_FUNCS{$fn}};
+    my $args = pop @val;
+    my $rtyp = "@val";
+    my $dfn = eval "\$${fn}_default";
+    $dfn = eval "\$${dfn}";
+    if (eval "\$${fn}_indirect" eq "true") {
+      print "    $fn = $dfn;\n";
+      foreach my $opt (@_) {
+        my $ofn = eval "\$${fn}_${opt}";
+        next if !$ofn;
+        next if "$ofn" eq "$dfn";
+        my $link = eval "\$${fn}_${opt}_link";
+        next if $link && $link eq "false";
+        my $cond = eval "\$have_${opt}";
+        print "    if (${cond}) $fn = $ofn;\n"
+      }
+    }
+  }
+}
+
+sub filter {
+  my @filtered;
+  foreach (@_) { push @filtered, $_ unless $disabled{$_}; }
+  return @filtered;
+}
+
+#
+# Helper functions for generating the arch specific RTCD files
+#
+sub common_top() {
+  my $include_guard = uc($opts{sym})."_H_";
+  print <<EOF;
+// This file is generated. Do not edit.
+#ifndef ${include_guard}
+#define ${include_guard}
+
+#ifdef RTCD_C
+#define RTCD_EXTERN
+#else
+#define RTCD_EXTERN extern
+#endif
+
+EOF
+
+process_forward_decls();
+print <<EOF;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+EOF
+declare_function_pointers("c", @ALL_ARCHS);
+
+print <<EOF;
+void $opts{sym}(void);
+
+EOF
+}
+
+sub common_bottom() {
+  print <<EOF;
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif
+EOF
+}
+
+sub x86() {
+  determine_indirection("c", @ALL_ARCHS);
+
+  # Assign the helper variable for each enabled extension
+  foreach my $opt (@ALL_ARCHS) {
+    my $opt_uc = uc $opt;
+    eval "\$have_${opt}=\"flags & HAS_${opt_uc}\"";
+  }
+
+  common_top;
+  print <<EOF;
+#ifdef RTCD_C
+#include "aom_ports/x86.h"
+static void setup_rtcd_internal(void)
+{
+    int flags = x86_simd_caps();
+
+    (void)flags;
+
+EOF
+
+  set_function_pointers("c", @ALL_ARCHS);
+
+  print <<EOF;
+}
+#endif
+EOF
+  common_bottom;
+}
+
+sub arm() {
+  determine_indirection("c", @ALL_ARCHS);
+
+  # Assign the helper variable for each enabled extension
+  foreach my $opt (@ALL_ARCHS) {
+    my $opt_uc = uc $opt;
+    eval "\$have_${opt}=\"flags & HAS_${opt_uc}\"";
+  }
+
+  common_top;
+  print <<EOF;
+#include "config/aom_config.h"
+
+#ifdef RTCD_C
+#include "aom_ports/arm.h"
+static void setup_rtcd_internal(void)
+{
+    int flags = aom_arm_cpu_caps();
+
+    (void)flags;
+
+EOF
+
+  set_function_pointers("c", @ALL_ARCHS);
+
+  print <<EOF;
+}
+#endif
+EOF
+  common_bottom;
+}
+
+sub mips() {
+  determine_indirection("c", @ALL_ARCHS);
+
+  # Assign the helper variable for each enabled extension
+  foreach my $opt (@ALL_ARCHS) {
+    my $opt_uc = uc $opt;
+    eval "\$have_${opt}=\"flags & HAS_${opt_uc}\"";
+  }
+
+  common_top;
+
+  print <<EOF;
+#include "config/aom_config.h"
+
+#ifdef RTCD_C
+static void setup_rtcd_internal(void)
+{
+EOF
+
+  set_function_pointers("c", @ALL_ARCHS);
+
+  print <<EOF;
+#if HAVE_DSPR2
+void aom_dsputil_static_init();
+aom_dsputil_static_init();
+#endif
+}
+#endif
+EOF
+  common_bottom;
+}
+
+sub ppc() {
+  determine_indirection("c", @ALL_ARCHS);
+
+  # Assign the helper variable for each enabled extension
+  foreach my $opt (@ALL_ARCHS) {
+    my $opt_uc = uc $opt;
+    eval "\$have_${opt}=\"flags & HAS_${opt_uc}\"";
+  }
+
+  common_top;
+
+  print <<EOF;
+#include "config/aom_config.h"
+
+#ifdef RTCD_C
+#include "aom_ports/ppc.h"
+static void setup_rtcd_internal(void)
+{
+  int flags = ppc_simd_caps();
+
+  (void)flags;
+
+EOF
+
+  set_function_pointers("c", @ALL_ARCHS);
+
+  print <<EOF;
+}
+#endif
+EOF
+  common_bottom;
+}
+
+sub unoptimized() {
+  determine_indirection "c";
+  common_top;
+  print <<EOF;
+#include "config/aom_config.h"
+
+#ifdef RTCD_C
+static void setup_rtcd_internal(void)
+{
+EOF
+
+  set_function_pointers "c";
+
+  print <<EOF;
+}
+#endif
+EOF
+  common_bottom;
+}
+
+#
+# Main Driver
+#
+
+&require("c");
+&require(keys %required);
+if ($opts{arch} eq 'x86') {
+  @ALL_ARCHS = filter(qw/mmx sse sse2 sse3 ssse3 sse4_1 sse4_2 avx avx2/);
+  x86;
+} elsif ($opts{arch} eq 'x86_64') {
+  @ALL_ARCHS = filter(qw/mmx sse sse2 sse3 ssse3 sse4_1 sse4_2 avx avx2/);
+  @REQUIRES = filter(qw/mmx sse sse2/);
+  &require(@REQUIRES);
+  x86;
+} elsif ($opts{arch} eq 'mips32' || $opts{arch} eq 'mips64') {
+  @ALL_ARCHS = filter("$opts{arch}");
+  if (aom_config("HAVE_DSPR2") eq "yes") {
+    @ALL_ARCHS = filter("$opts{arch}", qw/dspr2/);
+  } elsif (aom_config("HAVE_MSA") eq "yes") {
+    @ALL_ARCHS = filter("$opts{arch}", qw/msa/);
+  }
+  mips;
+} elsif ($opts{arch} =~ /armv7\w?/) {
+  @ALL_ARCHS = filter(qw/neon/);
+  arm;
+} elsif ($opts{arch} eq 'armv8' || $opts{arch} eq 'arm64' ) {
+  @ALL_ARCHS = filter(qw/neon/);
+  &require("neon");
+  arm;
+} elsif ($opts{arch} eq 'ppc') {
+  @ALL_ARCHS = filter(qw/vsx/);
+  ppc;
+} else {
+  unoptimized;
+}
+
+__END__
+
+=head1 NAME
+
+rtcd -
+
+=head1 SYNOPSIS
+
+Usage: rtcd.pl [options] FILE
+
+See 'perldoc rtcd.pl' for more details.
+
+=head1 DESCRIPTION
+
+Reads the Run Time CPU Detections definitions from FILE and generates a
+C header file on stdout.
+
+=head1 OPTIONS
+
+Options:
+  --arch=ARCH       Architecture to generate defs for (required)
+  --disable-EXT     Disable support for EXT extensions
+  --require-EXT     Require support for EXT extensions
+  --sym=SYMBOL      Unique symbol to use for RTCD initialization function
+  --config=FILE     Path to file containing C preprocessor directives to parse
diff --git a/third_party/aom/build/cmake/util.cmake b/third_party/aom/build/cmake/util.cmake
index a0c705691..b70ec4013 100644
--- a/third_party/aom/build/cmake/util.cmake
+++ b/third_party/aom/build/cmake/util.cmake
@@ -13,19 +13,21 @@ if(AOM_BUILD_CMAKE_UTIL_CMAKE_)
 endif() # AOM_BUILD_CMAKE_UTIL_CMAKE_
 set(AOM_BUILD_CMAKE_UTIL_CMAKE_ 1)
 
+# Directory where generated sources will be written.
+set(AOM_GEN_SRC_DIR "${AOM_CONFIG_DIR}/gen_src")
+
 # Creates dummy source file in $AOM_CONFIG_DIR named $basename.$extension and
 # returns the full path to the dummy source file via the $out_file_path
 # parameter.
-function(create_dummy_source_file basename extension out_file_path)
-  set(dummy_source_file "${AOM_CONFIG_DIR}/${basename}_dummy.${extension}")
+macro(create_dummy_source_file basename extension out_file_path)
+  set(dummy_source_file "${AOM_GEN_SRC_DIR}/${basename}_dummy.${extension}")
   file(
     WRITE
       "${dummy_source_file}" "// Generated file. DO NOT EDIT!\n"
       "// ${target_name} needs a ${extension} file to force link language, \n"
       "// or to silence a harmless CMake warning: Ignore me.\n"
       "void ${target_name}_dummy_function(void) {}\n")
-  set(${out_file_path} ${dummy_source_file} PARENT_SCOPE)
-endfunction()
+endmacro()
 
 # Convenience function for adding a dummy source file to $target_name using
 # $extension as the file extension. Wraps create_dummy_source_file().
@@ -86,3 +88,84 @@ function(set_compiler_launcher launcher_flag launcher_name)
   endif()
 endfunction()
 
+# Sentinel value used to detect when a variable has been set via the -D argument
+# passed to CMake on the command line.
+set(cmake_cmdline_helpstring "No help, variable specified on the command line.")
+
+# Wrapper macro for set() that does some book keeping to help with storage of
+# build configuration information.
+#
+# Sets the default value for variable $name when the value of $name has not
+# already been set via the CMake command line.
+#
+# The names of variables defaulted through this macro are added to
+# $AOM_CONFIG_VARS to facilitate build logging and diagnostics.
+macro(set_aom_detect_var name value type helpstring)
+  unset(list_index)
+  list(FIND AOM_DETECT_VARS ${name} list_index)
+  if(${list_index} EQUAL -1)
+    list(APPEND AOM_DETECT_VARS ${name})
+  endif()
+
+  # Update the variable only when it does not carry the CMake assigned help
+  # string for variables specified via the command line.
+  unset(cache_helpstring)
+  get_property(cache_helpstring CACHE ${name} PROPERTY HELPSTRING)
+  if(NOT "${cache_helpstring}" STREQUAL "${cmake_cmdline_helpstring}")
+    set(${name} ${value} CACHE ${type} "${helpstring}")
+    mark_as_advanced(${name})
+  else()
+    message(
+      WARNING
+        "${name} has been set by CMake, but it may be overridden by the build "
+        "system during environment detection")
+  endif()
+endmacro()
+
+# Wrapper macro for set() that does some book keeping to help with storage of
+# build configuration information.
+#
+# Sets the default value for variable $name when the value of $name has not
+# already been set via the CMake command line.
+#
+# The names of variables defaulted through this macro are added to
+# $AOM_CONFIG_VARS to facilitate build logging and diagnostics.
+macro(set_aom_config_var name value type helpstring)
+  unset(list_index)
+  list(FIND AOM_CONFIG_VARS ${name} list_index)
+  if(${list_index} EQUAL -1)
+    list(APPEND AOM_CONFIG_VARS ${name})
+  endif()
+
+  # Update the variable only when it does not carry the CMake assigned help
+  # string for variables specified via the command line.
+  unset(cache_helpstring)
+  get_property(cache_helpstring CACHE ${name} PROPERTY HELPSTRING)
+  if(NOT "${cache_helpstring}" STREQUAL "${cmake_cmdline_helpstring}")
+    set(${name} ${value} CACHE ${type} "${helpstring}")
+  endif()
+endmacro()
+
+# Wrapper macro for option() that does some book keeping to help with storage of
+# build configuration information.
+#
+# Sets the default value for variable $name when the value of $name has not
+# already been set via the CMake command line.
+#
+# The names of variables defaulted through this macro are added to
+# $AOM_OPTION_VARS to facilitate build logging and diagnostics.
+macro(set_aom_option_var name helpstring value)
+  unset(list_index)
+  list(FIND AOM_OPTION_VARS ${name} list_index)
+  if(${list_index} EQUAL -1)
+    list(APPEND AOM_OPTION_VARS ${name})
+  endif()
+
+  # Update the variable only when it does not carry the CMake assigned help
+  # string for variables specified via the command line.
+  unset(cache_helpstring)
+  get_property(cache_helpstring CACHE ${name} PROPERTY HELPSTRING)
+  if(NOT "${cache_helpstring}" STREQUAL "${cmake_cmdline_helpstring}")
+    option(${name} "${helpstring}" ${value})
+  endif()
+endmacro()
diff --git a/third_party/aom/build/cmake/version.pl b/third_party/aom/build/cmake/version.pl
index 7c0608aeb..7d23f2b27 100755
--- a/third_party/aom/build/cmake/version.pl
+++ b/third_party/aom/build/cmake/version.pl
@@ -14,7 +14,7 @@ use warnings;
 use 5.010;
 use Getopt::Long;
 
-my $git_desc;
+my $git_desc = '';
 my $version_data;
 my $version_filename;
 GetOptions('version_data=s' => \$version_data,
@@ -68,7 +68,7 @@ if (length($git_desc) > 0) {
 open(my $version_file, '>', $version_filename) or
   die("Cannot open $version_filename: $!");
 
-my $version_packed = "((VERSION_MAJOR<<16)|(VERSION_MINOR<<8)|(VERSION_PATCH))";
+my $version_packed = "((VERSION_MAJOR << 16) | (VERSION_MINOR << 8) | (VERSION_PATCH))";
 my $year = (localtime)[5] + 1900;
 my $lic_block = << "EOF";
 /*
@@ -91,7 +91,8 @@ $lic_block
 #define VERSION_MINOR $version_minor
 #define VERSION_PATCH $version_patch
 #define VERSION_EXTRA \"$version_extra\"
-#define VERSION_PACKED $version_packed
+#define VERSION_PACKED \\
+  $version_packed
 #define VERSION_STRING_NOSP \"$git_desc\"
 #define VERSION_STRING \" $git_desc\"
 EOF
@@ -102,7 +103,8 @@ $lic_block
 #define VERSION_MINOR $version_minor
 #define VERSION_PATCH $version_patch
 #define VERSION_EXTRA \"$version_extra\"
-#define VERSION_PACKED $version_packed
+#define VERSION_PACKED \\
+  $version_packed
 #define VERSION_STRING_NOSP \"v$version_string\"
 #define VERSION_STRING \" v$version_string\"
 EOF