问题描述
我正在构建一个PhoneGap应用，该应用需要播放AAC音频。使用本机 WebView 可以很好地工作，但是我想在针对API 16-20的构建中使用Crosswalk，因为我的应用程序中的某些CSS功能在Android上根本无法使用4.x。
I'm building a PhoneGap app which needs to play AAC audio. It works well using the native WebView, but I would like to use Crosswalk on a build targeting APIs 16-20 because some CSS features in my app do not work at all on Android 4.x.
当我复制项目以添加Crosswalk Lite时，可以看到该应用程序可以正常运行，除了< audio> 元素指向AAC文件。这是因为。
When I make a copy of the project to add Crosswalk Lite, I can see that the app works except for the <audio> element pointing to a AAC file. This is because Crosswalk does not ship with proprietary codecs by default.
链接的页面上说：
$ xwalk/gyp_xwalk -Dmediacodecs_EULA=1
然后构建Crosswalk。
中的 ffmpegsumo.dll 或 libffmpegsumo.so 会在构建输出目录中包含专有编解码器。
Then build Crosswalk. The ffmpegsumo.dll or libffmpegsumo.so in the build output directory will contain the proprietary codecs.
有关更多详细信息，请参见。
Refer to Crosswalk Build Instruction for more details.
但是，我使用建议的插件添加了Crosswalk，因此我得到了没有专有编解码器的预构建库：
However, I am adding Crosswalk using the suggested plug-in, thus I get pre-built libraries without proprietary codecs:
phonegap plugin add cordova-plugin-crosswalk-webview --variable XWALK_MODE="lite" --save
如何将专有编解码器集成到Cordova Crosswalk插件中？
How can I integrate proprietary codecs in the Cordova Crosswalk plug-in?
推荐答案
I managed to understand the (convoluted) process of building everything. This answer deals with the process of compiling a custom build of the full Crosswalk (not the lite version).
实际上，我决定最终使用标准版本，并用MP3替换AAC音频，但我认为此答案可能对将来参考有用。
Actually, I decided to finally use the standard build and replace AAC audio with MP3s, but I thought this answer could be useful for future reference.
我在Ubuntu 16.04 Docker容器中编译了Crosswalk，以避免污染我的系统并确保我拥有正确的Linux版本。标准映像是准系统，因此我安装了一些依赖项。我还设置了一个共享文件夹来访问已编译的文件：
I compiled Crosswalk in a Ubuntu 16.04 Docker container to avoid "polluting" my system and to ensure I had the right Linux version. The standard image is pretty barebones so I installed some dependencies. I also set up a shared folder to access the compiled files:
docker run -it -v /home/andrea/shared:/shared ubuntu:16.04 /bin/bash
apt update
apt install -y python git nano lsb-release sudo wget curl software-properties-common
export EDITOR=nano # life it too short to learn vi
最后，有必要：
apt-add-repository multiverse
要求
按照depot_tools .html＃_setting_up rel = nofollow noreferrer>在文档中：
Requirements
Install the depot_tools as outlined in the documentation:
git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git
export PATH=$PATH:/path/to/depot_tools
使用以下命令初始化工作目录：
Initialize a working directory with:
mkdir crosswalk-checkout
cd crosswalk-checkout
export XWALK_OS_ANDROID=1
gclient config --name src/xwalk https://github.com/crosswalk-project/crosswalk.git
然后使用 nano .gclient 编辑配置文件，并添加以下行：
Then edit the config file with nano .gclient and add the following line:
target_os = ['android']
保存f
尝试与以下对象进行首次同步：
Attempt a first sync with:
gclient sync
此命令将失败，但可以。指令说：
This command will fail but it's OK. The instructions say:
调整 install-build-deps.sh 文件，然后运行它：
Adjust the install-build-deps.sh file and then run it:
sed -si "s/msttcorefonts/ttf-mscorefonts-installer/g" src/build/install-build-deps.sh
sudo ./src/build/install-build-deps-android.sh
再次运行 gclient sync 并等待直到正确完成。
Run gclient sync again and wait until it finishes correctly.
通过检查文件 src / xwalk /build/common.gypi 和 src / tools / mb / mb_config.pyl ，我们可以看到我们需要添加 ffmpeg_branding = Chrome 。
By inspecting the files src/xwalk/build/common.gypi and src/tools/mb/mb_config.pyl, we can see that we need to add ffmpeg_branding="Chrome" in the build arguments.
为防止以后出现错误，请安装与libnotify相关的开发包：
To prevent an error later on, install the development package related to libnotify:
sudo apt install libnotify-dev
移动到 src 目录并打开配置：
Move to the src directory and open the configuration:
cd src/
gn args out/Default
确保内容如下：
import("//xwalk/build/android.gni")
target_os = "android"
is_debug = false
ffmpeg_branding = "Chrome"
use_sysroot = false
参数 use_sysroot = false 可以防止出现另一个错误。保存文件时，您应该会看到以下内容：
The parameters use_sysroot = false prevents yet another error. When saving the file, you should see something like this:
Waiting for editor on "/home/utente/crosswalk-checkout/src/out/Default/args.gn"...
Generating files...
Done. Wrote 6060 targets from 1003 files in 2416ms
问题 cd .. 并再次运行 gclient sync 。
最后，要构建核心库，请执行以下操作：
Finally, to build the core library do:
cd src/
ninja -C out/Default xwalk_core_library
这将为ARM构建库，并生成位于以下位置的AAR文件：
This will build the library for ARM, producing an AAR file located at:
src/out/Default/xwalk_core_library.aar
将此文件安全地复制
使用以下方法返回args：
Get back to the args with:
gn args out/Default
添加以下行：
target_cpu = "x86"
保存文件，再次运行 gclient sync ，然后重复 ninja 命令。复制现在包含x86库的新AAR文件。
Save the file, run gclient sync again and then repeat the ninja command. Make a copy of the new AAR file which now contains the x86 libraries.
标准的Cordova Crosswalk插件将单个AAR文件与两个平台的库一起使用。 Raphael Kubo da Costa的建议如何制作此单个存档：
The standard Cordova Crosswalk plug-in uses a single AAR file with libraries for both platforms. This message by Raphael Kubo da Costa suggests how to produce this single archive:
最后，要在科尔多瓦插件中使用自定义构建的AAR文件，请参见。
Finally, to use the custom built AAR file in the Cordova plug-in, see How to change the Crosswalk version used by the Cordova Crosswalk Webview plugin.
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