环境 ubuntu21.04 + Android NDK r21e(下载 Android NDK 可以参考编译x264)
gitee链接(编译出的 android faac 静态库和动态库以及头文件)
1.下载faac
wget https://nchc.dl.sourceforge.net/project/faac/faac-src/faac-1.29/faac-1.29.9.2.tar.gztar -xvf faac-1.29.9.2.tar.gz
2.编写编译脚本
cd faac-1.29.9.2/touch build_faac.shgedit build_faac.sh
脚本内容如下
#!/bin/bashPREFIX=/home/hg/faac-1.29.9.2/androidexport NDK=/home/hg/android-ndk-r21eTOOLCHAIN=$NDK/toolchains/llvm/prebuilt/linux-x86_64export CC=$TOOLCHAIN/bin/armv7a-linux-androideabi21-clangexport CFLAGS="-O0 -g -fPIC"./configure --prefix=$PREFIX --host=arm-linux-androideabi --with-pic make cleanmake install
3.运行脚本
sudo chmod +x build_faac.shbash build_faac.sh
生成了android/armv7a目录以及相应的文件
下面说明下是怎么写出来的这个脚本
在终端输入 bash configure --help 输出内容如下
hg@ubuntu:~/faac-1.29.9.2$ bash configure -help`configure' configures faac 1.29.9.2 to adapt to many kinds of systems.Usage: configure [OPTION]..、[VAR=VALUE]...To assign environment variables (e.g., CC, CFLAGS...), specify them asVAR=VALUE、 See below for descriptions of some of the useful variables.Defaults for the options are specified in brackets.Configuration: -h, --help display this help and exit --help=short display options specific to this package --help=recursive display the short help of all the included packages -V, --version display version information and exit -q, --quiet, --silent do not print `checking ...' messages --cache-file=FILE cache test results in FILE [disabled] -C, --config-cache alias for `--cache-file=config.cache' -n, --no-create do not create output files --srcdir=DIR find the sources in DIR [configure dir or `..']Installation directories: --prefix=PREFIX install architecture-independent files in PREFIX [/usr/local] --exec-prefix=EPREFIX install architecture-dependent files in EPREFIX [PREFIX]By default, `make install' will install all the files in`/usr/local/bin', `/usr/local/lib' etc、 You can specifyan installation prefix other than `/usr/local' using `--prefix',for instance `--prefix=$HOME'.For better control, use the options below.Fine tuning of the installation directories: --bindir=DIR user executables [EPREFIX/bin] --sbindir=DIR system admin executables [EPREFIX/sbin] --libexecdir=DIR program executables [EPREFIX/libexec] --sysconfdir=DIR read-only single-machine data [PREFIX/etc] --sharedstatedir=DIR modifiable architecture-independent data [PREFIX/com] --localstatedir=DIR modifiable single-machine data [PREFIX/var] --runstatedir=DIR modifiable per-process data [LOCALSTATEDIR/run] --libdir=DIR object code libraries [EPREFIX/lib] --includedir=DIR C header files [PREFIX/include] --oldincludedir=DIR C header files for non-gcc [/usr/include] --datarootdir=DIR read-only arch.-independent data root [PREFIX/share] --datadir=DIR read-only architecture-independent data [DATAROOTDIR] --infodir=DIR info documentation [DATAROOTDIR/info] --localedir=DIR locale-dependent data [DATAROOTDIR/locale] --mandir=DIR man documentation [DATAROOTDIR/man] --docdir=DIR documentation root [DATAROOTDIR/doc/faac] --htmldir=DIR html documentation [DOCDIR] --dvidir=DIR dvi documentation [DOCDIR] --pdfdir=DIR pdf documentation [DOCDIR] --psdir=DIR ps documentation [DOCDIR]Program names: --program-prefix=PREFIX prepend PREFIX to installed program names --program-suffix=SUFFIX append SUFFIX to installed program names --program-transform-name=PROGRAM run sed PROGRAM on installed program namesSystem types: --build=BUILD configure for building on BUILD [guessed] --host=HOST cross-compile to build programs to run on HOST [BUILD]Optional Features: --disable-option-checking ignore unrecognized --enable/--with options --disable-FEATURE do not include FEATURE (same as --enable-FEATURE=no) --enable-FEATURE[=ARG] include FEATURE [ARG=yes] --enable-silent-rules less verbose build output (undo: "make V=1") --disable-silent-rules verbose build output (undo: "make V=0") --enable-drm Digital Radio Mondiale support --enable-dependency-tracking do not reject slow dependency extractors --disable-dependency-tracking speeds up one-time build --enable-shared[=PKGS] build shared libraries [default=yes] --enable-static[=PKGS] build static libraries [default=yes] --enable-fast-install[=PKGS] optimize for fast installation [default=yes] --disable-libtool-lock avoid locking (might break parallel builds) --disable-largefile omit support for large filesOptional Packages: --with-PACKAGE[=ARG] use PACKAGE [ARG=yes] --without-PACKAGE do not use PACKAGE (same as --with-PACKAGE=no) --with-pic[=PKGS] try to use only PIC/non-PIC objects [default=use both] --with-aix-soname=aix|svr4|both shared library versioning (aka "SONAME") variant to provide on AIX, [default=aix]. --with-gnu-ld assume the C compiler uses GNU ld [default=no] --with-sysroot[=DIR] Search for dependent libraries within DIR (or the compiler's sysroot if not specified).Some influential environment variables: CC C compiler command CFLAGS C compiler flags LDFLAGS linker flags, e.g、-L if you have libraries in a nonstandard directory LIBS libraries to pass to the linker, e.g、-l CPPFLAGS (Objective) C/C++ preprocessor flags, e.g、-I
将以上选项设置即可
其中-with-pic猜测这个选项是为了生成与位置无关的指令，也就是生成相对地址指令，这是 so 库需要的，但是我已经在 CFLAGS中指定了 -fpic 不知道二者是否都是一样的功能。
因为我们是为了生成 armv7a 平台下的 so 库，所以我们需要使用 armv7a-linux-androideabi21-clang ， 这里我并不清楚到底使用哪个版本的clang，因为我使用的ndk版本是 android-ndk-r21e ,而且我自己的Android 项目的最低兼容是21，所以我使用了 armv7a-linux-androideabi21-clang ，也就是在编译脚本中写的
export CC=$TOOLCHAIN/bin/armv7a-linux-androideabi21-clang
因为 faac 是用 C 语言写的，所以我认为不需要配置C++编译器的相关参数