如何使用 cygwin 和 android ndk r9c 在 windows 上编译 ffmpeg-2.2.2 [英] How to compile ffmpeg-2.2.2 on windows with cygwin and android ndk r9c

问题描述

有人编译成功了

ffmpeg-2.2.2 在带有 cygwin 和 android ndkr9c 的 windows 上?

ffmpeg-2.2.2 on windows with cygwin and android ndkr9c ?

或者可以指点我一个最新的教程吗?

Or can point me to an up to date tutorial ?

(http://www.roman10.net/how-to-build-ffmpeg-with-ndk-r9/ 对我不起作用我得到 Makefile:2: config.mak: 没有那个文件...cygwin admin devel gnome 已完全安装并且 make -v ok )

(http://www.roman10.net/how-to-build-ffmpeg-with-ndk-r9/ isn't working for me i get Makefile:2: config.mak: No such file... cygwin admin devel gnome is completely installed and make -v ok )

我需要将视频转换为图像(用于动态壁纸)...你知道吗?方法还是 ffmpeg 最好?

I need to convert a video to images(for live-wallpaper)... do you know a better method or is ffmpeg the best ?

谢谢

推荐答案

从 Roman 的 教程.以下更改适用于 Windows:您应该使用 NDK make.exe，而不是来自 cygwin 的那个.所以，我只是在我的 build_android.sh 中写了 d:/dev/Android/ndk/prebuilt/windows-x86_64/bin/make.exe.出于某种奇怪的原因，我无法运行 make clean - 但我现在只是选择忽略这个问题.

Start with Roman's tutorial. Following changes apply to Windows: you should use the NDK make.exe, not the one from cygwin. So, I simply wrote d:/dev/Android/ndk/prebuilt/windows-x86_64/bin/make.exe in my build_android.sh. For some weird reason, I could not run make clean - but I simply chose to ignore this problem for now.

跟着教程，别忘了设置

TOOLCHAIN=$NDK/toolchains/arm-linux-androideabi-4.8/prebuilt/windows-x86_64

另外，使用混合样式的路径，即 d:/dev/whatever 而不是 cygwin 样式的 /cygdrive/d/dev/whatever>.注意不要使用带空格的路径 - 既不用于 ndk 安装，也不用于 ffmpeg git clone.

Also, use mixed-style paths, i.e. d:/dev/whatever and not cygwin style /cygdrive/d/dev/whatever. Be careful not to use paths with spaces - neither for ndk installation, nor for ffmpeg git clone.

使用 ffmpeg 2.2，您可以将 --target-os=android 用于 ./configure，而不是修改 ./configure 文件，如步骤 2 中所述.

With ffmpeg 2.2, you can use --target-os=android for ./configure, instead of mangling ./configure file as described in step 2.

在我的机器上，我没有 pr 和 od 命令.我选择简单地伪造它们，写作

On my machine, I did not have pr and od commands. I chose simply to fake them, writing

echo 'cat $3' > ./pr
echo 'echo od' > ./od

这些不会破坏构建.

所以，我的构建过程如下:

So, my build process is as follows:

git clean -d -f -x
./configure --enable-shared --disable-static --disable-doc --disable-ffmpeg --disable-ffplay --disable-ffprobe --disable-ffserver --disable-avdevice --disable-doc --disable-symver --cross-prefix=d:/android-ndk-r9c/toolchains/arm-linux-androideabi-4.8/prebuilt/windows-x86_64/bin/arm-linux-androideabi- --target-os=android --arch=arm --enable-cross-compile --sysroot=d:/android-ndk-r9c/platforms/android-9/arch-arm/ --extra-cflags="-Os -fpic"

编译确实显示了一些警告，但 .so 文件都生成了.

Compilation does display some warnings, but the .so files are all produced.

为了启用 NEON，我使用了

To enable NEON, I used

--extra-cflags="-Os -fpic -marm -march=armv7-a -mfloat-abi=softfp -mfpu=neon"
--extra-ldflags="-Wl,--fix-cortex-a8"

现在，libavcodec.so 无法再构建:链接器列表上的文件太多.所以，在它崩溃后，我手动启动了链接器:

Now, libavcodec.so could not be built anymore: too many files on the linker list. So, after it crashed, I launched the linker manually:

$ d:/Dev/Android/ndk/toolchains/arm-linux-androideabi-4.8/prebuilt/windows-x86_64//bin/arm-linux-androideabi-gcc  -shared -Wl,-Bsymbolic -Wl,--version-script,libavcodec/libavcodec.ver -Llibavcodec -Llibavdevice -Llibavfilter -Llibavformat -Llibavresample -Llibavutil -Llibpostproc -Llibswscale -Llibswresample -Wl,--fix-cortex-a8  --sysroot=d:/Dev/Android/ndk/platforms/android-9/arch-arm/ -isysroot d:/Dev/Android/ndk/platforms/android-9/arch-arm/ -Wl,--as-needed -Wl,--warn-common -Wl,-rpath-link=libpostproc:libswresample:libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil:libavresample @libavcodec/libavcodec.list -lswresample -lavutil -lm -lz -pthread -o libavcodec/libavcodec.so.55

我按如下方式修补 library.mak 文件:对于 $(SUBDIR)$(SLIBNAME_WITH_MAJOR)，替换

I patch the library.mak file as follows: for $(SUBDIR)$(SLIBNAME_WITH_MAJOR), replace

$$(LD) $(SHFLAGS) $(LDFLAGS) $$(LD_O) $$(filter %.o,$$^) $(FFEXTRALIBS)

与

$(Q)echo >$(SUBDIR)lib$(NAME).list $(wordlist 1,400,$(filter %.o,$$<))
$(Q)echo >>$(SUBDIR)lib$(NAME).list $(wordlist 401,999,$(filter %.o,$$<))
$$(LD) $(SHFLAGS) $(LDFLAGS) $$(LD_O) @$(SUBDIR)lib$(NAME).list $(FFEXTRALIBS)

.. 然后，make 顺利进行.

.. and from there, make proceeded smoothly.

PS:我使用make -n libavcodec/libavcodec.so.55来准备响应文件 libavcodec/libavcodec.list.

PS: I used make -n libavcodec/libavcodec.so.55 to prepare the response file libavcodec/libavcodec.list.

PPS:这里是另一篇文章有助于为 Android 构建和使用 ffmpeg.

PPS: Here is another article that helps to build and use ffmpeg for Android.

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