QMediaPlayer没有在Ubuntu16.04/QT5.6上播放任何东西

Question

我在Ubuntu16.04上使用了官方的QT5.6SDK，当我尝试播放一个mp3文件时，我只得到：

defaultServiceProvider::requestService(): no service found for - "org.qt-project.qt.mediaplayer"

代码非常简单：

mMediaPlayer->setMedia(QUrl::fromLocalFile(myMp3File));
mMediaPlayer->play();

这可以在Android上工作，以前在我的Ubuntu14.04机器上也是如此。我遗漏了什么？在默认情况下，所有必需的gstreamer (by文档)东西似乎都已经安装好了，但仍然无法工作：

$ dpkg -l | grep gstream
ii  gir1.2-gstreamer-1.0                                 1.8.2-1~ubuntu1                                             amd64        GObject introspection data for the GStreamer library
ii  gstreamer1.0-alsa:amd64                              1.8.2-1ubuntu0.1                                            amd64        GStreamer plugin for ALSA
ii  gstreamer1.0-clutter-3.0                             3.0.18-1                                                    amd64        Clutter PLugin for GStreamer 1.0
ii  gstreamer1.0-fluendo-mp3:amd64                       0.10.32.debian-1                                            amd64        Fluendo mp3 decoder GStreamer 1.0 plugin
ii  gstreamer1.0-libav:amd64                             1.8.2-1~ubuntu1                                             amd64        libav plugin for GStreamer
ii  gstreamer1.0-plugins-bad:amd64                       1.8.2-1ubuntu0.1                                            amd64        GStreamer plugins from the "bad" set
ii  gstreamer1.0-plugins-bad-faad:amd64                  1.8.2-1ubuntu0.1                                            amd64        GStreamer faad plugin from the "bad" set
ii  gstreamer1.0-plugins-bad-videoparsers:amd64          1.8.2-1ubuntu0.1                                            amd64        GStreamer videoparsers plugin from the "bad" set
ii  gstreamer1.0-plugins-base:amd64                      1.8.2-1ubuntu0.1                                            amd64        GStreamer plugins from the "base" set
ii  gstreamer1.0-plugins-base-apps                       1.8.2-1ubuntu0.1                                            amd64        GStreamer helper programs from the "base" set
ii  gstreamer1.0-plugins-good:amd64                      1.8.2-1ubuntu0.1                                            amd64        GStreamer plugins from the "good" set
ii  gstreamer1.0-plugins-ugly:amd64                      1.8.2-1ubuntu0.1                                            amd64        GStreamer plugins from the "ugly" set
ii  gstreamer1.0-plugins-ugly-amr:amd64                  1.8.2-1ubuntu0.1                                            amd64        GStreamer plugins from the "ugly" set
ii  gstreamer1.0-pulseaudio:amd64                        1.8.2-1ubuntu0.1                                            amd64        GStreamer plugin for PulseAudio
ii  gstreamer1.0-tools                                   1.8.2-1~ubuntu1                                             amd64        Tools for use with GStreamer
ii  gstreamer1.0-x:amd64                                 1.8.2-1ubuntu0.1                                            amd64        GStreamer plugins for X11 and Pango
ii  libgstreamer-plugins-bad1.0-0:amd64                  1.8.2-1ubuntu0.1                                            amd64        GStreamer development files for libraries from the "bad" set
ii  libgstreamer-plugins-base1.0-0:amd64                 1.8.2-1ubuntu0.1                                            amd64        GStreamer libraries from the "base" set
ii  libgstreamer-plugins-good1.0-0:amd64                 1.8.2-1ubuntu0.1                                            amd64        GStreamer development files for libraries from the "good" set
ii  libgstreamer1.0-0:amd64                              1.8.2-1~ubuntu1                                             amd64        Core GStreamer libraries and elements
ii  libreoffice-avmedia-backend-gstreamer                1:5.1.4-0ubuntu1                                            amd64        GStreamer backend for LibreOffice

...and，当然，我的声音在其他方面是完美的。

Answer 1

首先，使用QT_DEBUG_PLUGINS=1运行应用程序以查看插件错误。

如果您看到关于“libgst音频-0.10.so.0”的错误，这是一个GStreamer版本问题。官方的Qt二进制文件似乎需要GStreamer 0.10。

我找到了解决办法：

• 使用随发行版附带的libqt，使用包管理器:这是我找到的最好的解决方案，因为它是用正确的GStreamer版本构建的。我使用不同的chroot来为嵌入不同GStreamer版本的发行版制作包。
• 从源代码编译Qt以启用GStreer1.0：未测试
• 安装Gstreamer 0.10 :我不推荐这个选项，如果你需要的话，我也不推荐在旧的发行版中使用chroot。