I am building ffmpeg now, but I always get an error after executing make

Question

Configure parameter /-- ./configure --prefix=/usr/workspace/android --disable-static --enable-shared --disable-ffplay --disable-ffprobe --disable-htmlpages --disable-manpages --disable-podpages --disable-txtpages --arch=arm --target-os=linux --cross-prefix=/usr/workspace/ndk/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/bin/arm-linux-androideabi- --sysroot=/usr/workspace/ndk/platforms/android-21/arch-arm --extra-cflags="-Os -fpic $ADDI_CFLAGS" --extra-ldflags="$ADDI_LDFLAGS" --/

 make execution error 
/--
In file included from ./libavformat/internal.h:24:0,
                 from libavdevice/alldevices.c:23:
/usr/workspace/ndk/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/lib/gcc/arm-linux-androideabi/4.9.x/include/stdint.h:9:26: fatal error: stdint.h: No such file or directory
 # include_next <stdint.h>
                          ^
compilation terminated.
make: *** [libavdevice/alldevices.o] Error 1

--/

Answer 1

Update to NDK r19 and use:

TOOLCHAIN=$NDK/toolchains/llvm/prebuilt/linux-x86_64/
./configure \
    --arch=arm \
    --target-os=android \
    --cc=$TOOLCHAIN/bin/armv7a-linux-androideabi21-clang \
    --cxx=$TOOLCHAIN/bin/armv7a-linux-androideabi21-clang++ \
    --cross-prefix=$TOOLCHAIN/bin/arm-linux-androideabi- \
    --extra-cflags="-Os -fpic" \
    --disable-static \
    --enable-shared \
    --disable-ffplay \
    --disable-ffprobe \
    --disable-htmlpages \
    --disable-manpages \
    --disable-podpages \
    --disable-txtpages

If for some reason you can't update your NDK, you need to use https://developer.android.com/ndk/guides/standalone_toolchain.