Update README.md

Author: dxjia

README.md

@@ -7,13 +7,56 @@
   android-ndk64-r10-linux-x86_64
 
 # 获取代码
-``
+```
   git clone git@github.com:dxjia/ffmpeg-for-android-shared-library.git
-``
+```
+
+# 介绍
+build_android.sh<br>
+```java
+#!/bin/bash
+export TMPDIR=/home/djia/tmpdir
+NDK=/home/djia/android/android-ndk-r10
+SYSROOT=$NDK/platforms/android-16/arch-arm/
+TOOLCHAIN=/home/djia/android/android-ndk-r10/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64
+function build_one
+{
+./configure \
+--prefix=$PREFIX \
+--enable-shared \
+--disable-static \
+--disable-doc \
+--disable-ffmpeg \
+--disable-ffplay \
+--disable-ffprobe \
+--disable-ffserver \
+--disable-doc \
+--disable-symver \
+--enable-small \
+--cross-prefix=$TOOLCHAIN/bin/arm-linux-androideabi- \
+--target-os=linux \
+--arch=arm \
+--enable-cross-compile \
+--sysroot=$SYSROOT \
+--extra-cflags="-Os -fpic $ADDI_CFLAGS" \
+--extra-ldflags="$ADDI_LDFLAGS" \
+$ADDITIONAL_CONFIGURE_FLAG
+make clean
+make
+make install
+}
+CPU=arm
+PREFIX=/root/workspace/ffmpeg_shared_compile/dxjia_ffmpeg_install
+ADDI_CFLAGS="-marm"
+build_one
+```
+
 
 #编译
+```
 cd source/ffmpeg<br>
 ./build_andrioid.sh
+```
 
 # Reference & Thanks
   [android-ffmpeg-tutorial](https://github.com/roman10/android-ffmpeg-tutorial)