在 OSX 上为 Android 编译 ffmpeg

Question

I'm trying to compile ffmpeg for Android, on OSX 10.12.4 .

Here are the steps I followed:

1°) Compile pkg-config

Download the sources from here . Extract && cd in the pkg-config folder.

export DST=/a/path/on/my/computer

./configure --with-internal-glib --prefix=$DST --exec-prefix=$DST
make -j2
make install

export PATH=$PATH:$DST/bin

2°) Compile ffmpeg

Download the sources from here . Extract && cd in the ffmpeg folder.

export NDK=/path/to/android-ndk-r15c
export PLATFORM_VERSION=android-26
export ARCH=arm
export PLATFORM=$NDK/platforms/$PLATFORM_VERSION/arch-$ARCH
export TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.9/prebuilt/darwin-x86_64

export PREFIX=$(pwd)/android/$ARCH

export ADDI_CFLAGS="-Os -fpic -marm"
export ADDI_CONFIGURE_FLAG=""
export ADDI_LDFLAGS=""

./configure \
  --prefix=$PREFIX \
  --enable-shared \
  --disable-static \
  --disable-doc \
  --disable-ffmpeg \
  --disable-ffplay \
  --disable-ffprobe \
  --disable-ffserver \
  --disable-symver \
  --disable-avdevice \
  \
  --pkg-config=pkg-config \
  \
  --cross-prefix=$TOOLCHAIN/bin/arm-linux-androideabi- \
  --target-os=linux \
  --arch=$ARCH \
  --enable-cross-compile \
  --sysroot=$PLATFORM \
  --extra-cflags="$ADDI_CFLAGS" \
  --extra-ldflags="$ADDI_LDFLAGS" \
  \
  $ADDI_CONFIGURE_FLAG

make -j2

Make fails with the following error:

AR  libavfilter/libavfilter.a
AR  libavformat/libavformat.a
CC  libavcodec/aaccoder.o
In file included from /Users/Tim/Library/Android/android-ndk-r15c/platforms/android-26/arch-arm/usr/include/asm/termbits.h:19:0,
from /Users/Tim/Library/Android/android-ndk-r15c/platforms/android-26/arch-arm/usr/include/asm-generic/termios.h:21,
from /Users/Tim/Library/Android/android-ndk-r15c/platforms/android-26/arch-arm/usr/include/asm/termios.h:19,
from /Users/Tim/Library/Android/android-ndk-r15c/platforms/android-26/arch-arm/usr/include/linux/termios.h:22,
from /Users/Tim/Library/Android/android-ndk-r15c/platforms/android-26/arch-arm/usr/include/sys/ioctl.h:37,
from ./libavutil/timer.h:36,
from ./libavutil/internal.h:42,
from ./libavutil/common.h:467,
from libavcodec/mathops.h:27,
from libavcodec/aaccoder.c:38:
libavcodec/aaccoder.c: In function 'search_for_ms':
libavcodec/aaccoder.c:803:25: error: expected identifier or '(' before numeric constant
int B0 = 0, B1 = 0;
^
libavcodec/aaccoder.c:865:28: error: lvalue required as left operand of assignment
B0 += b1+b2;
^
libavcodec/aaccoder.c:866:25: error: 'B1' undeclared (first use in this function)
B1 += b3+b4;
^
libavcodec/aaccoder.c:866:25: note: each undeclared identifier is reported only once for each function it appears in
make: *** [libavcodec/aaccoder.o] Error 1
make: *** Waiting for unfinished jobs....

I'm able to fix that error by renaming B0 & B1 variables in the source to A0 & A1 (don't know why it fixes the problem), but then it fails somewhere else. I guess something is wrong in my config, and I'd prefer to avoid having to patch the source.

So the questions are:

• does someone know what's wrong here? Do I need to give some args to gcc?
• is the --target-os=linux correct, or should it be --target-os=darwin? Is target-os the OS where the compilation is done, or where ffmpeg will be executed? By using darwin, I can compile using --enable-static, but not --enable-shared (which I want).

Note: I need to compile it myself as I want only an arm version, with HTTPS support. Thus I can't use the existing built versions.

Answer 1

I also met this problem when I tried to build the ffmpeg 3.4 the latest version.I wish you could try the 3.3 version.I built it successfully. I doubt that latest version is unstable and with some bug. By the way,You can take some answer By this article: http://alientechlab.com/how-to-build-ffmpeg-for-android/

Answer 2

Issue closed by FFmpeg team

--target-os=android solves it

./configure \ 
... 
--target-os=android