Structured --arch, --cc and --cross-prefix evaluating

README.md

@@ -7,8 +7,8 @@ Here is a script that downloads the source code of [FFmpeg](https://www.ffmpeg.o
 The actual content of all this directories depends on how the FFmpeg was configured before assembling. For my purpose I enabled only *libavcodec*, *libavformat*, *libavutil* and *libswscale*, but you can set your own configuration to make the FFmpeg you need.
 The version of FFmpeg here by default is **4.1.4** (but can be overridden). And the script expects to use **at least** Android NDK **r19** (*r20* also works ok). Starting with FFmpeg 4.1 and NDK r19 the whole process became much simpler.
 
-## Supported Android architectures
-
+## Supported Android ABIs
+a
 * armeabi-v7a
 * arm64-v8a
 * x86

ffmpeg-android-maker.sh

@@ -96,67 +96,78 @@ function ensureSources() {
   esac
 }
 
-# Actual magic of configuring and compiling of FFmpeg for a certain architecture.
-# Supported architectures are: armeabi-v7a, arm64-v8a, x86 and x86_64
+# Actual magic of configuring and compiling of FFmpeg for a certain ABIs.
+# Supported ABIs are: armeabi-v7a, arm64-v8a, x86 and x86_64
 function assemble() {
   cd ${FFMPEG_SOURCES}
 
-  ARCH=$1
+  ABI=$1
   API_LEVEL=$2
 
   TOOLCHAIN_PATH=${ANDROID_NDK_HOME}/toolchains/llvm/prebuilt/${HOST_TAG}
   SYSROOT=${TOOLCHAIN_PATH}/sysroot
 
-  CC_ANDROID_POSTFIX=
   EXTRA_CFLAGS=
   EXTRA_CONFIGURE_FLAGS=
 
-  case $ARCH in
+  TARGET_TRIPLE_MACHINE_BINUTILS=
+  TARGET_TRIPLE_MACHINE_CC=
+  TARGET_TRIPLE_OS="android"
+
+  case $ABI in
   	armeabi-v7a)
-      FFMPEG_ARCH_FLAG=arm
-      CROSS_PREFIX=arm-linux-androideabi-
-      CC_PREFIX=armv7a
-      CC_ANDROID_POSTFIX=eabi
+      #cc       armv7a-linux-androideabi16-clang
+      #binutils arm   -linux-androideabi  -ld
+      TARGET_TRIPLE_MACHINE_BINUTILS=arm
+      TARGET_TRIPLE_MACHINE_CC=armv7a
+      TARGET_TRIPLE_OS=androideabi
   		;;
     arm64-v8a)
-      FFMPEG_ARCH_FLAG=aarch64
-      CROSS_PREFIX=aarch64-linux-android-
-      CC_PREFIX=aarch64
+      #cc       aarch64-linux-android21-clang
+      #binutils aarch64-linux-android  -ld
+      TARGET_TRIPLE_MACHINE_BINUTILS=aarch64
   		;;
     x86)
-      FFMPEG_ARCH_FLAG=x86
-      CROSS_PREFIX=i686-linux-android-
-      CC_PREFIX=i686
+      #cc       i686-linux-android16-clang
+      #binutils i686-linux-android  -ld
+      TARGET_TRIPLE_MACHINE_BINUTILS=i686
+
       EXTRA_CFLAGS=-mno-stackrealign
       EXTRA_CONFIGURE_FLAGS=--disable-asm
   		;;
     x86_64)
-      FFMPEG_ARCH_FLAG=x86_64
-      CROSS_PREFIX=x86_64-linux-android-
-      CC_PREFIX=x86_64
+      #cc       x86_64-linux-android21-clang
+      #binutils x86_64-linux-android  -ld
+      TARGET_TRIPLE_MACHINE_BINUTILS=x86_64
+
       EXTRA_CONFIGURE_FLAGS=--x86asmexe=${TOOLCHAIN_PATH}/bin/yasm
   		;;
   esac
 
-  CC=${TOOLCHAIN_PATH}/bin/${CC_PREFIX}-linux-android${CC_ANDROID_POSTFIX}${API_LEVEL}-clang
+  # If the cc-specific variable isn't set, we fallback to binutils version
+  [ -z "${TARGET_TRIPLE_MACHINE_CC}" ] && TARGET_TRIPLE_MACHINE_CC=${TARGET_TRIPLE_MACHINE_BINUTILS}
+
+  CROSS_PREFIX=${TOOLCHAIN_PATH}/bin/${TARGET_TRIPLE_MACHINE_BINUTILS}-linux-${TARGET_TRIPLE_OS}-
+
+  CC=${TOOLCHAIN_PATH}/bin/${TARGET_TRIPLE_MACHINE_CC}-linux-${TARGET_TRIPLE_OS}${API_LEVEL}-clang
 
   DECODERS_TO_ENABLE=
   while IFS= read -r line; do DECODERS_TO_ENABLE="${DECODERS_TO_ENABLE} --enable-decoder=$line"; done < ${BASE_DIR}/video_decoders_list.txt
 
   ./configure \
-    --prefix=${BUILD_DIR}/${ARCH} \
-    --disable-doc \
+    --prefix=${BUILD_DIR}/${ABI} \
     --enable-cross-compile \
-    --cross-prefix=${TOOLCHAIN_PATH}/bin/${CROSS_PREFIX} \
+    --cross-prefix=${CROSS_PREFIX} \
+    --arch=${TARGET_TRIPLE_MACHINE_BINUTILS} \
     --target-os=android \
     --cc=${CC} \
-    --arch=${FFMPEG_ARCH_FLAG} \
     --extra-cflags="-O3 -fPIC $EXTRA_CFLAGS" \
     --sysroot=${SYSROOT} \
     --enable-shared \
     --disable-static \
-    --disable-debug \
+    --disable-doc \
     --disable-runtime-cpudetect \
+    --disable-debug \
     --disable-programs \
     --disable-muxers \
     --disable-encoders \
@@ -177,7 +188,7 @@ function assemble() {
 
     # Saving stats about text relocation presence.
     # If the result file doesn't have 'TEXTREL' at all, then we are good.
-    ${TOOLCHAIN_PATH}/bin/${CROSS_PREFIX}readelf --dynamic ${BUILD_DIR}/${ARCH}/lib/*.so | grep 'TEXTREL\|File' >> ${STATS_DIR}/text-relocations.txt
+    ${CROSS_PREFIX}readelf --dynamic ${BUILD_DIR}/${ABI}/lib/*.so | grep 'TEXTREL\|File' >> ${STATS_DIR}/text-relocations.txt
 
     cd ${BASE_DIR}
 }
@@ -194,16 +205,16 @@ function installLibs() {
 }
 
 function build() {
-  ARCH=$1
+  ABI=$1
   ANDROID_API=$2
 
-  assemble ${ARCH} ${ANDROID_API}
-  installLibs ${ARCH}
+  assemble ${ABI} ${ANDROID_API}
+  installLibs ${ABI}
 }
 
-# Placing build header files into the /bin directory
-# Note, there is a only one such a folder since this headers are the same for all architectures
-# May not be true for different configurations though
+# Placing build header files into the /bin directory.
+# Note, there is a only one such a folder since this headers are the same for all ABIs.
+# May not be true for different configurations though.
 function installHeaders() {
   cd ${BUILD_DIR}
   cd "$(ls -1 | head -n1)"