解决Android NDK编译FFmpeg 4.2.2的x86 cpu版时的问题

老规矩,编译环境:Win10 1903,WSL ubuntu,ndk r20b,FFmpeg 4.2.2,首先分享下编译脚本:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
#!/bin/bash
make clean
 
export NDK=/home/kres/android-ndk-r20b
TOOLCHAIN=$NDK/toolchains/llvm/prebuilt/linux-x86_64/
API=21
 
function build_android
{
    echo "Compiling FFmpeg for $CPU"
    ./configure \
        --prefix=$PREFIX \
        --enable-neon \
        --enable-hwaccels \
        --enable-gpl \
        --enable-postproc \
        --enable-shared \
        --enable-jni \
        --enable-mediacodec \
        --disable-decoders \
            --enable-decoder=h264_mediacodec \
            --enable-decoder=vp9 \
            --enable-decoder=h264 \
            --enable-decoder=mpeg4 \
            --enable-decoder=aac \
            --enable-decoder=aac_latm \
            --enable-decoder=mjpeg \
            --enable-decoder=png \
            --enable-decoder=mpeg4_mediacodec \
        --disable-encoders \
            --enable-encoder=vp9_vaapi --enable-encoder=h264_nvenc --enable-encoder=h264_v4l2m2m --enable-encoder=hevc_nvenc \
        --disable-demuxers \
            --enable-demuxer=rtsp --enable-demuxer=rtp --enable-demuxer=flv --enable-demuxer=h264 \
        --disable-muxers \
            --enable-muxer=rtsp --enable-muxer=rtp --enable-muxer=flv --enable-muxer=h264 \
        --disable-parsers \
            --enable-parser=mpeg4video --enable-parser=aac --enable-parser=h264 --enable-parser=vp9 \
        --disable-protocols \
            --enable-protocol=rtmp --enable-protocol=rtp --enable-protocol=tcp --enable-protocol=udp \
        --disable-bsfs \
        --disable-indevs --enable-indev=v4l2 \
        --disable-outdevs \
        --disable-filters \
        --disable-postproc \
        --disable-static \
        --disable-doc \
        --disable-ffmpeg \
        --disable-ffplay \
        --disable-ffprobe \
        --enable-avdevice \
        --disable-doc \
        --disable-symver \
        --cross-prefix=$CROSS_PREFIX \
        --target-os=android \
        --arch=$ARCH \
        --cpu=$CPU \
        --cc=$CC \
        --cxx=$CXX \
        --enable-cross-compile \
        --sysroot=$SYSROOT \
        --extra-cflags="-Os -fpic $OPTIMIZE_CFLAGS" \
        --extra-ldflags="$ADDI_LDFLAGS" \
        $ADDITIONAL_CONFIGURE_FLAG
 
        make clean
        make -j6
        make install
        echo "The Compilation of FFmpeg for $CPU is completed"
 
}
    #armv8-a
    ARCH=arm64
    CPU=armv8-a
    CC=$TOOLCHAIN/bin/aarch64-linux-android$API-clang
    CXX=$TOOLCHAIN/bin/aarch64-linux-android$API-clang++
    SYSROOT=$NDK/toolchains/llvm/prebuilt/linux-x86_64/sysroot
    CROSS_PREFIX=$TOOLCHAIN/bin/aarch64-linux-android-
    PREFIX=$(pwd)/android/$CPU
    OPTIMIZE_CFLAGS="-march=$CPU"
    build_android
 
    #armv7-a
    ARCH=arm
    CPU=armv7-a
    CC=$TOOLCHAIN/bin/armv7a-linux-androideabi$API-clang
    CXX=$TOOLCHAIN/bin/armv7a-linux-androideabi$API-clang++
    SYSROOT=$NDK/toolchains/llvm/prebuilt/linux-x86_64/sysroot
    CROSS_PREFIX=$TOOLCHAIN/bin/arm-linux-androideabi-
    PREFIX=$(pwd)/android/$CPU
    OPTIMIZE_CFLAGS="-mfloat-abi=softfp -mfpu=vfp -marm -march=$CPU "
    build_android
 
    #x86
    ARCH=x86
    CPU=x86
    CC=$TOOLCHAIN/bin/i686-linux-android$API-clang
    CXX=$TOOLCHAIN/bin/i686-linux-android$API-clang++
    SYSROOT=$NDK/toolchains/llvm/prebuilt/linux-x86_64/sysroot
    CROSS_PREFIX=$TOOLCHAIN/bin/i686-linux-android-
    PREFIX=$(pwd)/android/$CPU
    OPTIMIZE_CFLAGS="-march=i686 -mtune=intel -mssse3 -mfpmath=sse -m32"
    build_android
 
    #x86_64
    ARCH=x86_64
    CPU=x86-64
    CC=$TOOLCHAIN/bin/x86_64-linux-android$API-clang
    CXX=$TOOLCHAIN/bin/x86_64-linux-android$API-clang++
    SYSROOT=$NDK/toolchains/llvm/prebuilt/linux-x86_64/sysroot
    CROSS_PREFIX=$TOOLCHAIN/bin/x86_64-linux-android-
    PREFIX=$(pwd)/android/$CPU
    OPTIMIZE_CFLAGS="-march=$CPU -msse4.2 -mpopcnt -m64 -mtune=intel"
    build_android

其中,在编译到x86 32位版时,会遇到“error: inline assembly requires more registers than available”的问题:

libavcodec/x86/cabac.h:193:9: error: inline assembly requires more registers than available
        BRANCHLESS_GET_CABAC("%0", "%q0", "(%4)", "%1", "%w1",
        ^
libavcodec/x86/cabac.h:143:9: note: expanded from macro 'BRANCHLESS_GET_CABAC'
        "movzbl "statep"    , "ret"                                     \n\t"\
        ^
libavcodec/x86/cabac.h:193:9: error: inline assembly requires more registers than available
libavcodec/x86/cabac.h:143:9: note: expanded from macro 'BRANCHLESS_GET_CABAC'
        "movzbl "statep"    , "ret"                                     \n\t"\
        ^
libavcodec/x86/cabac.h:193:9: error: inline assembly requires more registers than available
libavcodec/x86/cabac.h:143:9: note: expanded from macro 'BRANCHLESS_GET_CABAC'
        "movzbl "statep"    , "ret"                                     \n\t"\
        ^
libavcodec/x86/cabac.h:193:9: error: inline assembly requires more registers than available
libavcodec/x86/cabac.h:143:9: note: expanded from macro 'BRANCHLESS_GET_CABAC'
        "movzbl "statep"    , "ret"                                     \n\t"\
        ^
libavcodec/x86/cabac.h:193:9: error: inline assembly requires more registers than available
libavcodec/x86/cabac.h:143:9: note: expanded from macro 'BRANCHLESS_GET_CABAC'
        "movzbl "statep"    , "ret"                                     \n\t"\
        ^
libavcodec/x86/cabac.h:193:9: error: inline assembly requires more registers than available
libavcodec/x86/cabac.h:143:9: note: expanded from macro 'BRANCHLESS_GET_CABAC'
        "movzbl "statep"    , "ret"                                     \n\t"\
        ^
libavcodec/x86/cabac.h:193:9: error: inline assembly requires more registers than available
libavcodec/x86/cabac.h:143:9CC  libavcodec/h264_refs.o
: note: expanded from macro 'BRANCHLESS_GET_CABAC'
        "movzbl "statep"    , "ret"                                     \n\t"\

各种修改编译脚本设置都无法解决,虽然ndk的32位abi感觉可能也不太会用到吧,但是强迫症发作还是想把它也编出来,最后查到这个: https://trac.ffmpeg.org/ticket/7796 ,研读后发现“ libavutil/x86/asm.h:75”中的

1
#define HAVE_7REGS (ARCH_X86_64 || (HAVE_EBX_AVAILABLE && HAVE_EBP_AVAILABLE))

修改为:

1
#define HAVE_7REGS (ARCH_X86_64)

就可以编译通过了,先记下,后面发现副作用以及其它更新时再做补充。

博主友情提示:

如您在评论中需要提及如QQ号、电子邮件地址或其他隐私敏感信息,欢迎使用>>博主专用加密工具v3<<处理后发布,原文只有博主可以看到。