Question

我为所有Android架构构建了ffmpeg库。但是有些细节令我困惑。首先让我逐步解释我是如何构建的。

我从中下载了最新版本的libx264 https://www.videolan.org/developers/x264.html
创建并运行build_all.sh脚本（在x264文件夹中），为（几乎）所有Android平台创建库。然后我在x264文件夹中获得了android文件夹。例如x264文件夹中的android/arm android/arm64 android/x86 android/x86_64。
我从https://ffmpeg.org/download.html

ffmpeg3.3.4

我创建了4个ffmpeg3.3.4文件夹副本。用android架构名称命名它们。与ffmpeg3.3.4-arm64 ffmpeg3.3.4-arm ffmpeg3.3.4-x86 ffmpeg3.3.4-x86_64
为android的每个平台创建了build_（architecture-name）.sh。然后根据其架构名称将'named'.sh files中的每一个移动到命名的ffmpeg文件夹。 E.g build_android_x86.sh =＆gt; ffmpeg3.3.4-x86

build_android_arm64.sh示例

#!/bin/bash
#Change NDK to your Android NDK location
NDK=$HOME/Android/Sdk/ndk-bundle
PLATFORM=$NDK/platforms/android-21/arch-arm64/
PREBUILT=$NDK/toolchains/aarch64-linux-android-4.9/prebuilt/linux-x86_64

GENERAL="\
--enable-small \
--enable-cross-compile \
--extra-libs="-lgcc" \
--arch=aarch64 \
--cc=$PREBUILT/bin/aarch64-linux-android-gcc \
--cross-prefix=$PREBUILT/bin/aarch64-linux-android- \
--nm=$PREBUILT/bin/aarch64-linux-android-nm \
--extra-cflags="-I../x264/android/arm64/include" \
--extra-ldflags="-L../x264/android/arm64/lib" "

MODULES="\
--enable-gpl \
--enable-libx264"



function build_arm64
{
  ./configure \
  --logfile=conflog.txt \
  --target-os=linux \
  --prefix=./android/arm64-v8a \
  ${GENERAL} \
  --sysroot=$PLATFORM \
  --extra-cflags="" \
  --extra-ldflags="-lx264 -Wl,-rpath-link=$PLATFORM/usr/lib -L$PLATFORM/usr/lib -nostdlib -lc -lm -ldl -llog" \
  --enable-shared \
  --disable-static \
  --disable-doc \
  --enable-zlib \
  ${MODULES}

  make clean
  make
  make install
}

build_arm64


echo Android ARM64 builds finished

将所有ffmpeg3.3.4-arm64 ffmpeg3.3.4-arm ffmpeg3.3.4-x86 ffmpeg3.3.4-x86_64个文件夹移至NDK_PATH（C:\Users\MyName\AppData\Local\Android\sdk\ndk-bundle）
将x264文件夹放在与ffmpeg文件夹相同的层次结构中 in（C:\Users\MyName\AppData\Local\Android\sdk\ndk-bundle）
在自己的ffmpeg文件夹中逐个运行build_android_x86.sh，build_android_x86_64.sh ..脚本中的每一个。然后我在ffmpeg文件夹中获得了android个文件夹。（创建的android个文件夹有库文件夹）例如ffmpeg3.3.4-x86/android/x86/(bin,inlude,lib,share)

为所有已创建的Android.mk文件夹创建了android个文件，并将其中每个文件夹移动到android / armName文件夹。例如Android.mk =＆gt; ffmpeg3.3.4-x86/android/x86/

LOCAL_PATH:= $(call my-dir)

include $(CLEAR_VARS)
LOCAL_MODULE:= libavcodec
LOCAL_SRC_FILES:= lib/libavcodec-57.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE:= libavformat
LOCAL_SRC_FILES:= lib/libavformat-57.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE:= libswscale
LOCAL_SRC_FILES:= lib/libswscale-4.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE:= libavutil
LOCAL_SRC_FILES:= lib/libavutil-55.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE:= libavfilter
LOCAL_SRC_FILES:= lib/libavfilter-6.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE:= libswresample
LOCAL_SRC_FILES:= lib/libswresample-2.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := postproc
LOCAL_SRC_FILES := lib/libpostproc-54.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_SHARED_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := avdevice
LOCAL_SRC_FILES := lib/libavdevice-57.so
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/include
include $(PREBUILT_SHARED_LIBRARY)

创建＆＃34;手臂命名＆＃34;我的项目的jni文件夹中的文件夹x86 x86_4 arm64 arm7（myproject/app/jni/x86，myproject/app/jni/x86_64）。
转到ndk路径逐个打开名为ffmpeg的文件夹，并将ffmpeg.c ffmpeg_filter.c ffmpeg_opt.c cmdutils.c个文件从ffmpeg文件夹复制到＆＃34; arm命名＆＃34;文件夹。例如ffmpeg.c =＆gt; myproject/app/jni/x86

在我的项目中创建了Android.mk文件。

LOCAL_PATH := $(call my-dir)
#$(warning $(LOCAL_PATH))

include $(CLEAR_VARS)
LOCAL_MODULE    := videoEdit
LOCAL_LDLIBS := -llog -ljnigraphics -lz -landroid
LOCAL_CFLAGS := -Wdeprecated-declarations
ANDROID_LIB := -landroid

$(info $(TARGET_ARCH_ABI))

ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)
    LOCAL_C_INCLUDES:=/Users/MyName/AppData/Local/Android/sdk/ndk-bundle/sources/ffmpeg-3.3.4-armeabi
    LOCAL_SRC_FILES :=  videoEdit.c arm7/ffmpeg.c arm7/ffmpeg_filter.c arm7/ffmpeg_opt.c arm7/cmdutils.c
    LOCAL_CFLAGS += -lx264 -Wl,--no-merge-exidx-entries
else

    ifeq ($(TARGET_ARCH_ABI),arm64-v8a)
            LOCAL_C_INCLUDES:=/Users/MyName/AppData/Local/Android/sdk/ndk-bundle/sources/ffmpeg-3.3.4-arm64-v8a
            LOCAL_SRC_FILES :=  videoEdit.c arm64/ffmpeg.c arm64/ffmpeg_filter.c arm64/ffmpeg_opt.c arm64/cmdutils.c
            LOCAL_CFLAGS += -funwind-tables -Wl,--no-merge-exidx-entries
    else

        ifeq ($(TARGET_ARCH_ABI),x86_64)
               LOCAL_C_INCLUDES:=/Users/MyName/AppData/Local/Android/sdk/ndk-bundle/sources/ffmpeg3.3.4-x86_64
               LOCAL_SRC_FILES :=  videoEdit.c x86_64/ffmpeg.c x86_64/ffmpeg_filter.c x86_64/ffmpeg_opt.c x86_64/cmdutils.c
        else
                LOCAL_C_INCLUDES:=/Users/MyName/AppData/Local/Android/sdk/ndk-bundle/sources/ffmpeg3.3.4-x86
                LOCAL_SRC_FILES :=  videoEdit.c x86/ffmpeg.c x86/ffmpeg_filter.c x86/ffmpeg_opt.c x86/cmdutils.c
        endif

    endif

endif

LOCAL_SHARED_LIBRARIES := libavformat libavcodec libswscale libavutil libswresample libavfilter libavdevice libpostproc

include $(BUILD_SHARED_LIBRARY)

ifeq ($(TARGET_ARCH_ABI),armeabi-v7a)

    $(call import-module,ffmpeg-3.3.4-armeabi/android/armeabi-v7a)

else

    ifeq ($(TARGET_ARCH_ABI),arm64-v8a)
            $(call import-module,ffmpeg-3.3.4-arm64-v8a/android/arm64-v8a)
    else

        ifeq ($(TARGET_ARCH_ABI),x86_64)
               $(call import-module,ffmpeg3.3.4-x86_64/android/x86_64)
        else
            $(call import-module,ffmpeg3.3.4-x86/android/i686-diasm)
        endif

    endif

endif

在我的项目中创建了Application.mk文件。

APP_ABI := armeabi-v7a, arm64-v8a, x86_64, x86
APP_PLATFORM := android-14

创建videoEdit.c而不是运行ndk-build构建命令。

构建时没有错误。我可以运行ffmpeg命令，但我认为这需要太多时间。例如，当我尝试运行hflip时，它会在15秒后翻转视频。

代码示例：

JNIEXPORT jint JNICALL Java_com_name_app_library_VideoEditer_natives_VideoEditer_flipHorizontally
(JNIEnv *env, jclass someclass, jstring inputFile, jstring outFile) {

    int numberOfArgs = 14;

    char** arguments = calloc(numberOfArgs, sizeof(char*));
    const char *in, *out;

    in = (*env)->GetStringUTFChars(env, inputFile, 0);
    out = (*env)->GetStringUTFChars(env, outFile, 0);

    arguments[0] = "ffmpeg";
    arguments[1] = "-i";
    arguments[2] = in;
    arguments[3] = "-c:v";
    arguments[4] = "libx264";
    arguments[5] = "-preset";
    arguments[6] = "ultrafast";
    arguments[7] = "-threads";
    arguments[8] = "5";
    arguments[9] = "-c:a";
    arguments[10] = "copy";
    arguments[11] = "-vf";
    arguments[12] = "hflip";
    arguments[13] = out;

    int i;
    for (i = 0; i < numberOfArgs; i++) {
        log_message(arguments[i]);
    }
    log_message("Printed all");

    main(numberOfArgs, arguments);
    free(arguments);
    (*env)->ReleaseStringUTFChars(env, inputFile, in);
    (*env)->ReleaseStringUTFChars(env, outFile, out);

    return 0;
}

FFmpeg在Android上运行的命令，在电子邮件上运行速度非常快，但在实际设备上运行速度非常慢。

令我困惑的另一件事是输出./configure命令。当我打开（例如）ffmpeg-3.3.4-arm64-v8a文件夹并在终端中运行./configure命令时。输出显示为ARCH x86 (generic)。对于所有平台输出都是相同的ARCH x86 (generic)。

在./configure文件夹

中输出ffmpeg-3.3.4-arm64-v8a命令

install prefix            /usr/local
source path               .
C compiler                gcc
C library                 glibc
ARCH                      x86 (generic)
big-endian                no
runtime cpu detection     yes
yasm                      yes
MMX enabled               yes
MMXEXT enabled            yes
3DNow! enabled            yes
3DNow! extended enabled   yes
SSE enabled               yes
SSSE3 enabled             yes
AESNI enabled             yes
AVX enabled               yes
XOP enabled               yes
FMA3 enabled              yes
FMA4 enabled              yes
i686 features enabled     yes
CMOV is fast              yes
EBX available             yes
EBP available             yes
debug symbols             yes
strip symbols             yes
optimize for size         no
optimizations             yes
static                    yes
shared                    no
postprocessing support    no
network support           yes
threading support         pthreads
safe bitstream reader     yes
texi2html enabled         no
perl enabled              yes
pod2man enabled           yes
makeinfo enabled          no
makeinfo supports HTML    no

External libraries:
iconv            xlib

编辑在ubuntu上执行的所有这些步骤都会将所有文件夹移动到窗口。所以不要混淆路径。

我要问的所有这些步骤是，我的步骤有什么不对。我应该遵循其他任何方式吗？为什么ffmpeg在真实设备上运行速度较慢。我想知道一件事，如何retrica，snapchat，instagram录制视频作为镜像翻转？它们是否在录制后翻转（如果它们是如何在一秒钟内完成此操作）或者是否在运行时录制视频？我觉得构建ffmpeg for android有点乱，做错事很容易。如果你看看我的步骤，问题并给我一个建议，我将不胜感激。

Answer 1

ARCH                      x86 (generic)

这肯定是错的，应该列出具体的架构。

我认为https://github.com/IljaKosynkin/FFmpeg-Development-Kit会对您有所帮助，我能够在第一次尝试时正确构建所有体系结构。您正在使用命令行ffmpeg，因此您需要启用该程序。

正确构建适用于所有Android架构的FFmpeg

1 个答案: