--- a/media/ffvpx/README_MOZILLA
+++ b/media/ffvpx/README_MOZILLA
@@ -2,28 +2,28 @@ This directory contains files used in ge
 (http://ffmpeg.org). The current files are from FFmpeg as of
 revision n3.4-1-g587fadaef1
 All source files match their path from the library's source archive.
 
 Currently, we only use the vp8 and vp9 portion of the library, and only on x86
 based platforms. If this changes, configuration files will most likely
 need to be updated.
 
-AVX2 must be disabled on Linux due to the use of yasm 1.1 on the build bots.
+AVX2 must be disabled on Linux 32 bits due to the use of yasm 1.1 on the build bots.
 Once yasm is upgraded to 1.2 or later, AVX2 code could be re-enabled.
 Add --disable-avx2 to configure on those platforms.
 
 configuration files were generated as follow using the configure script:
-./configure --disable-everything --disable-protocols --disable-demuxers --disable-muxers --disable-filters --disable-programs --disable-doc --disable-parsers --enable-parser=vp8 --enable-parser=vp9 --enable-decoder=vp8 --enable-decoder=vp9 --disable-static --enable-shared --disable-debug --disable-sdl2 --disable-libxcb --disable-securetransport --disable-iconv --disable-swresample --disable-swscale --disable-avdevice --disable-avfilter --disable-avformat --disable-d3d11va --disable-dxva2 --disable-vaapi --disable-vda --disable-vdpau --disable-videotoolbox --enable-decoder=flac --enable-asm --enable-yasm
+./configure --disable-everything --disable-protocols --disable-demuxers --disable-muxers --disable-filters --disable-programs --disable-doc --disable-parsers --enable-parser=vp8 --enable-parser=vp9 --enable-decoder=vp8 --enable-decoder=vp9 --disable-static --enable-shared --disable-debug --disable-sdl2 --disable-libxcb --disable-securetransport --disable-iconv --disable-swresample --disable-swscale --disable-avdevice --disable-avfilter --disable-avformat --disable-d3d11va --disable-dxva2 --disable-vaapi --disable-vda --disable-vdpau --disable-videotoolbox --enable-decoder=flac --enable-asm --enable-x86asm
 
 config*:
 replace: /HAVE_(MALLOC_H|ARC4RANDOM|LOCALTIME_R|MEMALIGN|POSIX_MEMALIGN)/d
 
 config_unix32.h:
-add to configure command: --disable-asm --disable-yasm --cc='clang -m32'
+add to configure command: --disable-asm --disable-x86asm --cc='clang -m32'
 
 config_android.h:
 ./configure --disable-everything --disable-protocols --disable-demuxers --disable-muxers --disable-filters --disable-programs --disable-doc --disable-parsers --disable-static --enable-shared --disable-debug --disable-sdl2 --disable-libxcb --disable-securetransport --disable-iconv --disable-swresample --disable-swscale --disable-avdevice --disable-avfilter --disable-avformat --disable-d3d11va --disable-dxva2 --disable-vaapi --disable-vda --disable-vdpau --disable-videotoolbox --enable-decoder=flac --disable-asm --cross-prefix=~/.mozbuild/android-ndk-r15c/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi- --target-os=linux --arch=arm --enable-cross-compile --sysroot=~/.mozbuild/android-ndk-r15c/platforms/android-24/arch-arm
 
 config_unix64.h/config_unix64.asm:
 replace: s/HAVE_SYSCTL 1/HAVE_SYSCTL 0
 
 config_win32/64.h/asm:

--- a/media/ffvpx/config_darwin64.asm
+++ b/media/ffvpx/config_darwin64.asm
@@ -173,17 +173,17 @@
 %define HAVE_RDTSC 0
 %define HAVE_SARESTART 1
 %define HAVE_SEM_TIMEDWAIT 1
 %define HAVE_SYNC_VAL_COMPARE_AND_SWAP 1
 %define HAVE_CABS 1
 %define HAVE_CEXP 1
 %define HAVE_INLINE_ASM 1
 %define HAVE_SYMVER 1
-%define HAVE_YASM 1
+%define HAVE_X86ASM 1
 %define HAVE_BIGENDIAN 0
 %define HAVE_FAST_UNALIGNED 1
 %define HAVE_ALSA_ASOUNDLIB_H 0
 %define HAVE_ALTIVEC_H 0
 %define HAVE_ARPA_INET_H 1
 %define HAVE_ASM_TYPES_H 0
 %define HAVE_CDIO_PARANOIA_H 0
 %define HAVE_CDIO_PARANOIA_PARANOIA_H 0

--- a/media/ffvpx/config_darwin64.h
+++ b/media/ffvpx/config_darwin64.h
@@ -189,17 +189,17 @@
 #define HAVE_RDTSC 0
 #define HAVE_SARESTART 1
 #define HAVE_SEM_TIMEDWAIT 1
 #define HAVE_SYNC_VAL_COMPARE_AND_SWAP 1
 #define HAVE_CABS 1
 #define HAVE_CEXP 1
 #define HAVE_INLINE_ASM 1
 #define HAVE_SYMVER 1
-#define HAVE_YASM 1
+#define HAVE_X86ASM 1
 #define HAVE_BIGENDIAN 0
 #define HAVE_FAST_UNALIGNED 1
 #define HAVE_INCOMPATIBLE_LIBAV_ABI 0
 #define HAVE_ALSA_ASOUNDLIB_H 0
 #define HAVE_ALTIVEC_H 0
 #define HAVE_ARPA_INET_H 1
 #define HAVE_ASM_TYPES_H 0
 #define HAVE_CDIO_PARANOIA_H 0

--- a/media/ffvpx/config_unix32.h
+++ b/media/ffvpx/config_unix32.h
@@ -189,17 +189,17 @@
 #define HAVE_RDTSC 0
 #define HAVE_SARESTART 1
 #define HAVE_SEM_TIMEDWAIT 1
 #define HAVE_SYNC_VAL_COMPARE_AND_SWAP 1
 #define HAVE_CABS 1
 #define HAVE_CEXP 1
 #define HAVE_INLINE_ASM 1
 #define HAVE_SYMVER 1
-#define HAVE_YASM 0
+#define HAVE_X86ASM 0
 #define HAVE_BIGENDIAN 0
 #define HAVE_FAST_UNALIGNED 0
 #define HAVE_ALSA_ASOUNDLIB_H 0
 #define HAVE_ALTIVEC_H 0
 #define HAVE_ARPA_INET_H 1
 #define HAVE_ASM_TYPES_H 1
 #define HAVE_CDIO_PARANOIA_H 0
 #define HAVE_CDIO_PARANOIA_PARANOIA_H 0

--- a/media/ffvpx/config_unix64.asm
+++ b/media/ffvpx/config_unix64.asm
@@ -173,17 +173,17 @@
 %define HAVE_RDTSC 0
 %define HAVE_SARESTART 1
 %define HAVE_SEM_TIMEDWAIT 1
 %define HAVE_SYNC_VAL_COMPARE_AND_SWAP 1
 %define HAVE_CABS 1
 %define HAVE_CEXP 1
 %define HAVE_INLINE_ASM 1
 %define HAVE_SYMVER 1
-%define HAVE_YASM 1
+%define HAVE_X86ASM 1
 %define HAVE_BIGENDIAN 0
 %define HAVE_FAST_UNALIGNED 1
 %define HAVE_ALSA_ASOUNDLIB_H 0
 %define HAVE_ALTIVEC_H 0
 %define HAVE_ARPA_INET_H 1
 %define HAVE_ASM_TYPES_H 1
 %define HAVE_CDIO_PARANOIA_H 0
 %define HAVE_CDIO_PARANOIA_PARANOIA_H 0

--- a/media/ffvpx/config_win32.asm
+++ b/media/ffvpx/config_win32.asm
@@ -173,17 +173,17 @@
 %define HAVE_RDTSC 1
 %define HAVE_SARESTART 0
 %define HAVE_SEM_TIMEDWAIT 1
 %define HAVE_SYNC_VAL_COMPARE_AND_SWAP 0
 %define HAVE_CABS 0
 %define HAVE_CEXP 0
 %define HAVE_INLINE_ASM 0
 %define HAVE_SYMVER 0
-%define HAVE_YASM 1
+%define HAVE_X86ASM 1
 %define HAVE_BIGENDIAN 0
 %define HAVE_FAST_UNALIGNED 1
 %define HAVE_ALSA_ASOUNDLIB_H 0
 %define HAVE_ALTIVEC_H 0
 %define HAVE_ARPA_INET_H 0
 %define HAVE_ASM_TYPES_H 0
 %define HAVE_CDIO_PARANOIA_H 0
 %define HAVE_CDIO_PARANOIA_PARANOIA_H 0

--- a/media/ffvpx/config_win32.h
+++ b/media/ffvpx/config_win32.h
@@ -189,17 +189,17 @@
 #define HAVE_RDTSC 1
 #define HAVE_SARESTART 0
 #define HAVE_SEM_TIMEDWAIT 1
 #define HAVE_SYNC_VAL_COMPARE_AND_SWAP 0
 #define HAVE_CABS 0
 #define HAVE_CEXP 0
 #define HAVE_INLINE_ASM 0
 #define HAVE_SYMVER 0
-#define HAVE_YASM 1
+#define HAVE_X86ASM 1
 #define HAVE_BIGENDIAN 0
 #define HAVE_FAST_UNALIGNED 1
 #define HAVE_ALSA_ASOUNDLIB_H 0
 #define HAVE_ALTIVEC_H 0
 #define HAVE_ARPA_INET_H 0
 #define HAVE_ASM_TYPES_H 0
 #define HAVE_CDIO_PARANOIA_H 0
 #define HAVE_CDIO_PARANOIA_PARANOIA_H 0

--- a/media/ffvpx/config_win64.asm
+++ b/media/ffvpx/config_win64.asm
@@ -173,17 +173,17 @@
 %define HAVE_RDTSC 1
 %define HAVE_SARESTART 0
 %define HAVE_SEM_TIMEDWAIT 1
 %define HAVE_SYNC_VAL_COMPARE_AND_SWAP 0
 %define HAVE_CABS 0
 %define HAVE_CEXP 0
 %define HAVE_INLINE_ASM 0
 %define HAVE_SYMVER 0
-%define HAVE_YASM 1
+%define HAVE_X86ASM 1
 %define HAVE_BIGENDIAN 0
 %define HAVE_FAST_UNALIGNED 1
 %define HAVE_ALSA_ASOUNDLIB_H 0
 %define HAVE_ALTIVEC_H 0
 %define HAVE_ARPA_INET_H 0
 %define HAVE_ASM_TYPES_H 0
 %define HAVE_CDIO_PARANOIA_H 0
 %define HAVE_CDIO_PARANOIA_PARANOIA_H 0

--- a/media/ffvpx/config_win64.h
+++ b/media/ffvpx/config_win64.h
@@ -189,17 +189,17 @@
 #define HAVE_RDTSC 1
 #define HAVE_SARESTART 0
 #define HAVE_SEM_TIMEDWAIT 1
 #define HAVE_SYNC_VAL_COMPARE_AND_SWAP 0
 #define HAVE_CABS 0
 #define HAVE_CEXP 0
 #define HAVE_INLINE_ASM 0
 #define HAVE_SYMVER 0
-#define HAVE_YASM 1
+#define HAVE_X86ASM 1
 #define HAVE_BIGENDIAN 0
 #define HAVE_FAST_UNALIGNED 1
 #define HAVE_ALSA_ASOUNDLIB_H 0
 #define HAVE_ALTIVEC_H 0
 #define HAVE_ARPA_INET_H 0
 #define HAVE_ASM_TYPES_H 0
 #define HAVE_CDIO_PARANOIA_H 0
 #define HAVE_CDIO_PARANOIA_PARANOIA_H 0