Install the gstreamer development dependency library to the project sysroot directory

背景

在项目中,需要实现一个gstreamer的pipeline,依赖libgstreamer1.0和libgstapp-1.0库,Because the system isx86_64环境,需要在i386的sysrootInstall these libraries below,基于这个背景,发现通过apt安装,然后从apt安装的cache路径,Get these libraries and copy them after unpackingsysrootDirectories are very handy.

首先,设置aptWhether to keep downloaded files when installing packagesdeb包：

# 禁止保存
echo 'Binary::apt::APT::Keep-Downloaded-Packages "0";' | sudo tee /etc/apt/apt.conf.d/10apt-keep-downloads

# 允许保存
echo 'Binary::apt::APT::Keep-Downloaded-Packages "1";' | sudo tee /etc/apt/apt.conf.d/10apt-keep-downloads

Execute the second command to runapt cache保存下载的deb包.

libgstapp-1.0.so -> libgstapp-1.0.so.0.1602.0

解包libgstreamer1.0 & libgstapp-1.0

通过dpkg-deb -X 解压缩就可以看到,libgstreamer1.0的库在libgstreamer1.0-0里面,而和libgstreamer1.0-devIt contains header files,pkg-config需要的pcfiles and pointerslibgstreamer1.0-0A symbolic link to the library inside.

建一个out目录,解包libgstreamer1.0-0_1.16.2-2_i386.deb到out目录,如下：

$ dpkg -X libgstreamer1.0-0_1.16.2-2_i386.deb out
./
./usr/
./usr/lib/
./usr/lib/i386-linux-gnu/
./usr/lib/i386-linux-gnu/gstreamer-1.0/
./usr/lib/i386-linux-gnu/gstreamer-1.0/libgstcoreelements.so
./usr/lib/i386-linux-gnu/gstreamer-1.0/libgstcoretracers.so
./usr/lib/i386-linux-gnu/gstreamer1.0/
./usr/lib/i386-linux-gnu/gstreamer1.0/gstreamer-1.0/
./usr/lib/i386-linux-gnu/gstreamer1.0/gstreamer-1.0/gst-plugin-scanner
./usr/lib/i386-linux-gnu/gstreamer1.0/gstreamer-1.0/gst-ptp-helper
./usr/lib/i386-linux-gnu/libgstbase-1.0.so.0.1602.0
./usr/lib/i386-linux-gnu/libgstcheck-1.0.so.0.1602.0
./usr/lib/i386-linux-gnu/libgstcontroller-1.0.so.0.1602.0
./usr/lib/i386-linux-gnu/libgstnet-1.0.so.0.1602.0
./usr/lib/i386-linux-gnu/libgstreamer-1.0.so.0.1602.0

# 符号链接
./usr/lib/i386-linux-gnu/libgstbase-1.0.so.0
./usr/lib/i386-linux-gnu/libgstcheck-1.0.so.0
./usr/lib/i386-linux-gnu/libgstcontroller-1.0.so.0
./usr/lib/i386-linux-gnu/libgstnet-1.0.so.0
./usr/lib/i386-linux-gnu/libgstreamer-1.0.so.0

As can be seen from this unpacked output,不带dev的debIt's all in the bagso库,包括符号链接.

再建立out-dev目录,通过dpkg-deb -X命令解包libgstreamer1.0-dev到out-dev目录：

$ dpkg-deb -X libgstreamer1.0-dev_1.16.2-2_i386.deb out-dev/

# include需要的文件
./
./usr/
./usr/bin/
./usr/bin/dh_gstscancodecs
./usr/include/
./usr/include/gstreamer-1.0/
./usr/include/gstreamer-1.0/gst/
./usr/include/gstreamer-1.0/gst/base/
./usr/include/gstreamer-1.0/gst/base/base-prelude.h
./usr/include/gstreamer-1.0/gst/base/base.h
./usr/include/gstreamer-1.0/gst/base/gstadapter.h
./usr/include/gstreamer-1.0/gst/base/gstaggregator.h
./usr/include/gstreamer-1.0/gst/base/gstbaseparse.h
./usr/include/gstreamer-1.0/gst/base/gstbasesink.h
./usr/include/gstreamer-1.0/gst/base/gstbasesrc.h
./usr/include/gstreamer-1.0/gst/base/gstbasetransform.h
./usr/include/gstreamer-1.0/gst/base/gstbitreader.h
./usr/include/gstreamer-1.0/gst/base/gstbitwriter.h
./usr/include/gstreamer-1.0/gst/base/gstbytereader.h
./usr/include/gstreamer-1.0/gst/base/gstbytewriter.h
./usr/include/gstreamer-1.0/gst/base/gstcollectpads.h
# ...


# pkg-config的pc文件
./usr/lib/
./usr/lib/i386-linux-gnu/
./usr/lib/i386-linux-gnu/gstreamer1.0/
./usr/lib/i386-linux-gnu/gstreamer1.0/gstreamer-1.0/
./usr/lib/i386-linux-gnu/gstreamer1.0/gstreamer-1.0/gst-codec-info-1.0
./usr/lib/i386-linux-gnu/pkgconfig/
./usr/lib/i386-linux-gnu/pkgconfig/gstreamer-1.0.pc
./usr/lib/i386-linux-gnu/pkgconfig/gstreamer-base-1.0.pc
./usr/lib/i386-linux-gnu/pkgconfig/gstreamer-check-1.0.pc
./usr/lib/i386-linux-gnu/pkgconfig/gstreamer-controller-1.0.pc
./usr/lib/i386-linux-gnu/pkgconfig/gstreamer-net-1.0.pc

# These libraries are just symlinks
./usr/lib/i386-linux-gnu/libgstbase-1.0.so
./usr/lib/i386-linux-gnu/libgstcheck-1.0.so
./usr/lib/i386-linux-gnu/libgstcontroller-1.0.so
./usr/lib/i386-linux-gnu/libgstnet-1.0.so
./usr/lib/i386-linux-gnu/libgstreamer-1.0.so

Complete these verifications,We can apply this process to our environment,such as our environmentsysroot路径是./i386-sysroot/

# step 1: 安装libgstreamer1.0库

sudo apt install libgstreamer1.0-0:i386
sudo apt install libgstreamer1.0-dev:i386


cp /var/cache/apt/archives/libgstreamer1.0-0_1.16.2-2_i386.deb .
cp /var/cache/apt/archives/libgstreamer1.0-dev_1.16.2-2_i386.deb .
dpkg-deb -X libgstreamer1.0-0_1.16.2-2_i386.deb ./i386-sysroot/
dpkg-deb -X libgstreamer1.0-dev_1.16.2-2_i386.deb ./i386-sysroot/



# step 2:安装libgstreamer-plugins-base1.0库

sudo apt install libgstreamer-plugins-base1.0-0:i386
sudo apt install libgstreamer-plugins-base1.0-dev:i386

cp /var/cache/apt/archives/libgstreamer-plugins-base1.0-0_1.16.2-4ubuntu0.1_i386.deb .
cp /var/cache/apt/archives/libgstreamer-plugins-base1.0-dev_1.16.2-4ubuntu0.1_i386.deb .

dpkg-deb -X libgstreamer-plugins-base1.0-0_1.16.2-4ubuntu0.1_i386.deb ./i386-sysroot/
dpkg-deb -X libgstreamer-plugins-base1.0-dev_1.16.2-4ubuntu0.1_i386.deb ./i386-sysroot/

完成上面两个步骤,sysroot中依赖gstreamerThe development environment is configured,You can also do this if you need other dependencies.

在ubuntu上,libgstreamer1.0-0这个名字可以通过apt search获得,比如：

$ apt search gstreamer

libgstreamer1.0-0/focal,now 1.16.2-2 amd64 [installed,automatic]
  Core GStreamer libraries and elements
  
libgstreamer1.0-dev/focal 1.16.2-2 amd64
  GStreamer core development files  
  
libgstreamer-plugins-base1.0-0/focal-updates,focal-security,now 1.16.2-4ubuntu0.1 amd64 [installed,automatic]
  GStreamer libraries from the "base" set

libgstreamer-plugins-base1.0-dev/focal-updates,focal-security 1.16.2-4ubuntu0.1 amd64
  GStreamer development files for libraries from the "base" set

It is added later when installingi386安装的就是32位的版本.

sudo apt install libgstreamer1.0-0:i386
sudo apt install libgstreamer1.0-dev:i386

附dpkg-deb命令解释

dpkg-deb命令是Debian Linux下的软件包管理工具,Packages can be packed and unpacked.

-X：Release the files in the package to the specified directory,And show the detailed process of releasing files