当我尝试在“ubuntu 软件中心”中安装“ubuntu 受限附加组件”时，它会显示一个警告对话框，提示必须删除以下项目：
libavcodec53
libavutil51
为什么？如果我选择安装“ubuntu restricted extras”，我会失去什么？
附言：我想我注意到 libavcodec53 在安装每日构建的 codeblocks 包时闪过……所以这是一种可能性。如果我安装“ubuntu restricted extras”，我的软件开发环境会不会受到破坏？
或者这些软件包是否需要删除，因为它们包含在“ubuntu 受限附加程序”中？如果是这样，为什么对话框没有提到这一点（并消除担忧和困惑）？
PS: 生成的输出apt-get -s install ubuntu-restricted-extras是
NOTE: This is only a simulation!
apt-get needs root privileges for real execution.
Keep also in mind that locking is deactivated,
so don't depend on the relevance to the real current situation!
Reading package lists...
Building dependency tree...
Reading state information...
The following extra packages will be installed:
cabextract gstreamer0.10-plugins-bad-multiverse libavcodec-extra-53
libavutil-extra-51 libfaac0 libmjpegtools-1.9 libopenjpeg2 libquicktime2
ttf-mscorefonts-installer unrar
Suggested packages:
libfaad0
The following packages will be REMOVED:
libavcodec53 libavutil51
The following NEW packages will be installed:
cabextract gstreamer0.10-plugins-bad-multiverse libavcodec-extra-53
libavutil-extra-51 libfaac0 libmjpegtools-1.9 libopenjpeg2 libquicktime2
ttf-mscorefonts-installer ubuntu-restricted-extras unrar
0 upgraded, 11 newly installed, 2 to remove and 0 not upgraded.
Remv libavutil51 [4:0.8.3-0ubuntu0.12.04.1] [libswscale2:amd64 libavcodec53:amd64 gstreamer0.10-ffmpeg:amd64 libpostproc52:amd64 libavformat53:amd64 ]
Inst libavutil-extra-51 (4:0.8.3ubuntu0.12.04.1 Ubuntu:12.04/precise-updates [amd64])
Conf libavutil-extra-51 (4:0.8.3ubuntu0.12.04.1 Ubuntu:12.04/precise-updates [amd64])
Inst libopenjpeg2 (1.3+dfsg-4 Ubuntu:12.04/precise [amd64])
Remv libavcodec53 [4:0.8.3-0ubuntu0.12.04.1] [gstreamer0.10-ffmpeg:amd64 libavformat53:amd64 ]
Inst libavcodec-extra-53 (4:0.8.3ubuntu0.12.04.1 Ubuntu:12.04/precise-updates [amd64])
Conf libopenjpeg2 (1.3+dfsg-4 Ubuntu:12.04/precise [amd64])
Conf libavcodec-extra-53 (4:0.8.3ubuntu0.12.04.1 Ubuntu:12.04/precise-updates [amd64])
Inst cabextract (1.4-1 Ubuntu:12.04/precise [amd64])
Inst ttf-mscorefonts-installer (3.4ubuntu3 Ubuntu:12.04/precise [all])
Inst libfaac0 (1.28-0ubuntu2 Ubuntu:12.04/precise [amd64])
Inst libquicktime2 (2:1.2.3-4build2 Ubuntu:12.04/precise [amd64])
Inst libmjpegtools-1.9 (1:1.9.0-0.5ubuntu7 Ubuntu:12.04/precise [amd64])
Inst gstreamer0.10-plugins-bad-multiverse (0.10.21-1 Ubuntu:12.04/precise [amd64])
Inst ubuntu-restricted-extras (57 Ubuntu:12.04/precise [amd64])
Inst unrar (1:4.0.3-1 Ubuntu:12.04/precise [amd64])
Conf cabextract (1.4-1 Ubuntu:12.04/precise [amd64])
Conf ttf-mscorefonts-installer (3.4ubuntu3 Ubuntu:12.04/precise [all])
Conf libfaac0 (1.28-0ubuntu2 Ubuntu:12.04/precise [amd64])
Conf libquicktime2 (2:1.2.3-4build2 Ubuntu:12.04/precise [amd64])
Conf libmjpegtools-1.9 (1:1.9.0-0.5ubuntu7 Ubuntu:12.04/precise [amd64])
Conf gstreamer0.10-plugins-bad-multiverse (0.10.21-1 Ubuntu:12.04/precise [amd64])
Conf ubuntu-restricted-extras (57 Ubuntu:12.04/precise [amd64])
Conf unrar (1:4.0.3-1 Ubuntu:12.04/precise [amd64])
答案1
因为-额外的将安装这些库的版本，以提供附加功能
安装ubuntu 受限附加功能除其他事项外，还将取代libavcodec53/libavutil51与libavcodec-extra-53和libavutil-extra-51。
这-额外的版本包含全部已删除的常规版本的功能；正如其名称所暗示的那样，它们添加功能这些可能受专利保护，因此不能包含在常规版本中。从这个意义上讲，它们是“严格超集”。
主要区别在于增加了 MP3、AAC、H.264 和 Xvid 编码器
快速差异常规/额外库中包含的版本之间的avconv主要区别在于添加了编码以下编解码器/格式的功能（创建）：
解码器JPEG2000还添加了基于视频的视频。