类型'video/x-h264没有解码器

I am trying to run one of qt sample apps without any modification. It is called player and it is a multimedia widget demonstration. My system is Ubuntu 16.04 64bit. When I try to play a video, I see the following error in the console:

我正在尝试运行一个qt示例应用程序，没有任何修改。它被称为播放器，它是一个多媒体小部件演示。我的系统是Ubuntu 16.04 64位。当我尝试播放视频时，我在控制台看到以下错误:

No decoder available for type 'video/x-h264

类型'video/x-h264没有解码器

Here is the full error after trying two different videos:

这是在尝试了两个不同的视频后的完全错误:

Starting /home/aras/Qt5.7.0_Sept2016/Examples/Qt-5.7/multimediawidgets/build-player-Sept2016-Debug/player...
Warning: "No decoder available for type 'video/x-h264, stream-format=(string)avc, alignment=(string)au, level=(string)3, profile=(string)constrained-baseline, codec_data=(buffer)0142e01eff0100192742e01ea9101405ff2e00d418041adb7a00f480f55ef7c04001000428de09c8, width=(int)640, height=(int)360, framerate=(fraction)2997/125, pixel-aspect-ratio=(fraction)1/1'."
Warning: "No decoder available for type 'video/x-h264, stream-format=(string)avc, alignment=(string)au, level=(string)3, profile=(string)constrained-baseline, codec_data=(buffer)0142e01eff0100192742e01ea9101405ff2e00d418041adb7a00f480f55ef7c04001000428de09c8, width=(int)640, height=(int)360, framerate=(fraction)2997/125, pixel-aspect-ratio=(fraction)1/1'."
Warning: "No decoder available for type 'video/x-h264, stream-format=(string)avc, pixel-aspect-ratio=(fraction)1/1, width=(int)1280, height=(int)720, framerate=(fraction)601600/10033'."

I have pretty much every package remotely related to gstreamer installed. When I run gst-inspect-1.0 I get a lot of output and the last line is:

我已经安装了几乎所有与gstreamer相关的远程软件包。当我运行gst- inspection -1.0时，我得到了很多输出，最后一行是:

Total count: 241 plugins (1 blacklist entry not shown), 1388 features

总数:241个插件(1个黑名单条目未显示)，1388个特性

~$ gst-inspect-1.0 |grep x-h264
typefindfunctions: video/x-h264: h264, x264, 264

:~$ gst-inspect-1.0 avdec_h264
Factory Details:
  Rank                     primary (256)
  Long-name                libav H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 decoder
  Klass                    Codec/Decoder/Video
  Description              libav h264 decoder

So it looks like to me that everything is installed properly. How come the Qt multimedia example does not work out of the box?

在我看来，一切都安装得很好。为什么Qt多媒体的例子不能用在盒子里?

1 个解决方案

#1

In you command line interface, run:

在你的命令行界面中，运行:

ldd /home/aras/Qt5.7.0_Sept2016/Examples/Qt-5.7/multimediawidgets/build-player-Sept2016-Debug/player
ldd echo $(which gst-inspect-1.0)

Look for lines that are referring to GStreamer, for example:

寻找那些指向GStreamer的行，例如:

libgstreamer-1.0.so.0 => /usr/lib/x86_64-linux-gnu/libgstreamer-1.0.so.0

libgstreamer-1.0.so。0 = > /usr/lib/x86_64-linux-gnu / libgstreamer-1.0.so.0

If the lines referring to GStreamer are not the same on both command results, you might have multiple GStreamer installations. Then try to specify a new LD_LIBRARY_PATH environment variable (DYLD_LIBRARY_PATH if you run OS-X) that only point to the directory where libgstreamer-1.0.so.0 is located thanks to the second GStreamer ldd result (gave by ldd echo $(which gst-inspect-1.0)).

如果在两个命令结果中引用GStreamer的行不相同，则可能有多个GStreamer安装。然后尝试指定一个新的LD_LIBRARY_PATH环境变量(如果运行OS-X，则是DYLD_LIBRARY_PATH)，该变量只指向libgstreamer-1.0.so所在的目录。0的位置要感谢第二个GStreamer ldd结果(由ldd echo $(gst- inspection -1.0)提供)。

For example, run:

例如,运行:

export LD_LIBRARY_PATH="/usr/local/lib:/usr/lib"