webrtc iOS端+Android编译2.直接运行命令--bitcode是开启bitcode功能，如果开启会导致生成

iOS端编译生成Framwork

1.修改路径webrtc/src/tools_webrtc/ios/build_ios_libs.py文件的cpu架构

DEFAULT_ARCHS = ENABLED_ARCHS = ['arm64','arm','x64','x86']

x64是模拟器，是mac电脑cpu
arm64是64位cpu
arm是32位cpu
x86是对应i386

2.直接运行命令--bitcode是开启bitcode功能，如果开启会导致生成的freamwork非常的大。所以一般不增加,切换到目录webrtc/src/tools_webrtc/ios

python build_ios_libs.py

3.最后输出的WebRTC.framework在webrtc/src/out_ios_libs目录下.

如果遇到只要部分cpu架构可以自己进行删除控制。
Note: 如果你的freamwork只有armv7 和 arm64架构，但是在你上传到App Store或者pod trunk 需要x86_64或i386 可以在工程配置Build Phase中的/bin/sh增加以以下脚本进行忽略。
遇到一个比较坑的问题在build_ios_libs.py有一行将x86架构移除，建议此处将它注释掉，否则一直编译不通过支持i386架构。

# Ignoring x86 except for static libraries for now because of a GN build issue
  # where the generated dynamic framework has the wrong architectures.
  if 'x86' in architectures and args.build_type != 'static_only':
    architectures.remove('x86')

APP_PATH="${TARGET_BUILD_DIR}/${WRAPPER_NAME}"

# This script loops through the frameworks embedded in the application and
# removes unused architectures.
find "$APP_PATH" -name '*.framework' -type d | while read -r FRAMEWORK
do
    FRAMEWORK_EXECUTABLE_NAME=$(defaults read "$FRAMEWORK/Info.plist" CFBundleExecutable)
    FRAMEWORK_EXECUTABLE_PATH="$FRAMEWORK/$FRAMEWORK_EXECUTABLE_NAME"
    echo "Executable is $FRAMEWORK_EXECUTABLE_PATH"

    EXTRACTED_ARCHS=()

    for ARCH in $ARCHS
    do
        echo "Extracting $ARCH from $FRAMEWORK_EXECUTABLE_NAME"
        lipo -extract "$ARCH" "$FRAMEWORK_EXECUTABLE_PATH" -o "$FRAMEWORK_EXECUTABLE_PATH-$ARCH"
        EXTRACTED_ARCHS+=("$FRAMEWORK_EXECUTABLE_PATH-$ARCH")
    done

    echo "Merging extracted architectures: ${ARCHS}"
    lipo -o "$FRAMEWORK_EXECUTABLE_PATH-merged" -create "${EXTRACTED_ARCHS[@]}"
    rm "${EXTRACTED_ARCHS[@]}"

    echo "Replacing original executable with thinned version"
    rm "$FRAMEWORK_EXECUTABLE_PATH"
    mv "$FRAMEWORK_EXECUTABLE_PATH-merged" "$FRAMEWORK_EXECUTABLE_PATH"

done

iOS端编译模拟器和真机测试demo

1.使用gn配置生成支持 Ninja编译的配置文件。（gn相关文档地址）
gn需要配置的的主要变量有以下：

target_os: 目标系统有：android, ios, mac，linux，chromeos，如：iOS设置为 target_os="ios"
target_cpu: 目标cpu架构有：
1. ios对应cpu有：arm,arm64,x64，x86
2. android对应cpu有：arm64，x86(32位)，x64(64位)
3. chromeos对应有：mips64el
4. linux对应：x86，x64
is_debug:是否是debug模式，默认是true
查找签名

security find-identity -p codesigning

# debug build for 64-bit iOS
gn gen out/ios_64 --args='target_os="ios" target_cpu="arm64" ios_code_signing_identity="827D1FA91405C2F887E5B7B127BD849B5D4B7B4F"'

# 编译真机测试Demo
ninja -C out/ios_64 AppRTCMobile

# 配置总工程
gn gen out/ios --args='target_os="ios" target_cpu="arm64" ios_code_signing_identity="827D1FA91405C2F887E5B7B127BD849B5D4B7B4F"' --ide=xcode
open -a Xcode.app out/ios/all.xcworkspace

Android编译

切换到代码目录
cd /src/

执行此脚本
. build/android/envsetup.sh

设置编译配置
gn gen out/out_android_armeabi-v7a --args='is_debug=false target_os="android" target_cpu="arm" rtc_use_h264=true ffmpeg_branding="Chrome"'

编译32位架构库 
ninja -C out/out_android_armeabi-v7a/
编译64位架构库
ninja -C out/out_android_armeabi-v8a/ AppRTCMobile