【发布时间】：2017-11-09 18:20:50
【问题描述】：
我正在尝试构建 ffmpeg 静态库并将它们链接到 android 项目以实现视频播放器。目标是使播放器能够从类似于 p2p 文件共享网络的各种来源接收视频文件。 （目标 api 是 21 级，比使用 MediaSource 的官方解决方案少 1 级）
我设法编译了ffmpeg from this repo（所有代码都按原样使用），但后来我遇到了链接问题。每当我尝试编译时，我都会得到在我的代码中调用的 ffmpeg 方法列表和一个简短的雄辩消息：
链接器命令失败，退出代码为 1
我不知道如何将 -v 标志传递给 android studio 中的链接器。如果有人暗示我，那就太好了。
我使用 android studio，使用 gradle 和 cmake 构建。
这是我的文件： build.gradle（项目）
// Top-level build file where you can add configuration options common to all sub-projects/modules.
buildscript {
repositories {
jcenter()
}
dependencies {
classpath 'com.android.tools.build:gradle:2.3.1'
// NOTE: Do not place your application dependencies here; they belong
// in the individual module build.gradle files
}
}
allprojects {
repositories {
jcenter()
}
}
task clean(type: Delete) {
delete rootProject.buildDir
}
build.gradle（模块）
apply plugin: 'com.android.application'
android {
compileSdkVersion 25
buildToolsVersion "25.0.3"
productFlavors {
x86 {
ndk {
abiFilter "x86"
}
}
arm {
ndk {
abiFilters "armeabi-v7a"
}
}
armv7 {
ndk {
abiFilters "armeabi-v7a"
}
}
}
defaultConfig {
applicationId "com.example.ledo.ndkapplication"
minSdkVersion 22
targetSdkVersion 25
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
externalNativeBuild {
cmake {
cppFlags "-std=c++11 -frtti -fexceptions"
arguments '-DANDROID_PLATFORM=android-16'
}
}
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
}
}
externalNativeBuild {
cmake {
path "CMakeLists.txt"
}
}
splits {
abi {
enable true
reset()
include 'x86', 'armeabi-v7a'
universalApk true
}
}
}
dependencies {
compile fileTree(dir: 'libs', include: ['*.jar'])
androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
exclude group: 'com.android.support', module: 'support-annotations'
})
compile 'com.android.support:appcompat-v7:25.3.1'
compile 'com.android.support.constraint:constraint-layout:1.0.2'
compile 'com.android.support:design:25.3.1'
compile 'com.writingminds:FFmpegAndroid:0.3.2'
testCompile 'junit:junit:4.12'
}
CMakeLists.txt
# For more information about using CMake with Android Studio, read the
# documentation: https://d.android.com/studio/projects/add-native-code.html
# Sets the minimum version of CMake required to build the native library.
cmake_minimum_required(VERSION 2.8)
# Creates and names a library, sets it as either STATIC
# or SHARED, and provides the relative paths to its source code.
# You can define multiple libraries, and CMake builds them for you.
# Gradle automatically packages shared libraries with your APK.
add_library( # Sets the name of the library.
native-lib
# Sets the library as a shared library.
SHARED
# Provides a relative path to your source file(s).
src/main/cpp/native-lib.cpp
src/main/cpp/NativePlayer.h
src/main/cpp/NativePlayer.cpp)
# Searches for a specified prebuilt library and stores the path as a
# variable. Because CMake includes system libraries in the search path by
# default, you only need to specify the name of the public NDK library
# you want to add. CMake verifies that the library exists before
# completing its build.
find_library( # Sets the name of the path variable.
log-lib
# Specifies the name of the NDK library that
# you want CMake to locate.
log )
find_library(png-lib png)
# Specifies libraries CMake should link to your target library. You
# can link multiple libraries, such as libraries you define in this
# build script, prebuilt third-party libraries, or system libraries.
#avcodec
#avfilter
#avformat
#avutil
#swresample
#swscale
#${ANDROID_ABI}
message(${ANDROID_ABI})
set(FFMPEG_ROOT_DIR src/main/libs/ffmpeg/${ANDROID_ABI})
add_library(avcodec STATIC IMPORTED)
add_library(avformat STATIC IMPORTED)
add_library(avfilter STATIC IMPORTED)
add_library(avutil STATIC IMPORTED)
add_library(swresample STATIC IMPORTED)
add_library(swscale STATIC IMPORTED)
#SET_TARGET_PROPERTIES(avcodec PROPERTIES LINKER_LANGUAGE C)
set_target_properties(avcodec PROPERTIES IMPORTED_LOCATION ${CMAKE_CURRENT_SOURCE_DIR}/${FFMPEG_ROOT_DIR}/lib/libavcodec.a)
#SET_TARGET_PROPERTIES(avfilter PROPERTIES LINKER_LANGUAGE C)
set_target_properties(avfilter PROPERTIES IMPORTED_LOCATION ${CMAKE_CURRENT_SOURCE_DIR}/${FFMPEG_ROOT_DIR}/lib/libavfilter.a)
#SET_TARGET_PROPERTIES(avformat PROPERTIES LINKER_LANGUAGE C)
set_target_properties(avformat PROPERTIES IMPORTED_LOCATION ${CMAKE_CURRENT_SOURCE_DIR}/${FFMPEG_ROOT_DIR}/lib/libavformat.a)
#SET_TARGET_PROPERTIES(avutil PROPERTIES LINKER_LANGUAGE C)
set_target_properties(avutil PROPERTIES IMPORTED_LOCATION ${CMAKE_CURRENT_SOURCE_DIR}/${FFMPEG_ROOT_DIR}/lib/libavutil.a)
#SET_TARGET_PROPERTIES(swresample PROPERTIES LINKER_LANGUAGE C)
set_target_properties(swresample PROPERTIES IMPORTED_LOCATION ${CMAKE_CURRENT_SOURCE_DIR}/${FFMPEG_ROOT_DIR}/lib/libswresample.a)
#SET_TARGET_PROPERTIES(swscale PROPERTIES LINKER_LANGUAGE C)
set_target_properties(swscale PROPERTIES IMPORTED_LOCATION ${CMAKE_CURRENT_SOURCE_DIR}/${FFMPEG_ROOT_DIR}/lib/libswscale.a)
include_directories( ${CMAKE_CURRENT_SOURCE_DIR}/${FFMPEG_ROOT_DIR}/include )
include_directories( ${CMAKE_CURRENT_SOURCE_DIR}/${FFMPEG_ROOT_DIR}/lib )
target_link_libraries( # Specifies the target library.
native-lib
# Links the target library to the log library
# included in the NDK.
${log-lib}
avcodec
avformat
#avfilter
#swresample
#swscale
#avutil
GLESv2)
我在以下位置有 .a 文件：
%PROJECT_DIR%/app/src/libs/ffmpeg/armeabi-v7a%PROJECT_DIR%/app/src/libs/ffmpeg/armeabi-v7a-neon%PROJECT_DIR%/app/src/libs/ffmpeg/x86
在我看来，链接器本身并没有丢失文件。 （如果我放错了位置，我会得到不同的输出。）
【问题讨论】：
标签： android android-studio ffmpeg android-ndk linker-errors