为什么我在运行GStreamer应用程序时会发出警告？

Question

I can compile the first gstreamer tutorial found here .

However, when try to run it, I get a warning like this:

(basic-tutorial-1:27661): GStreamer-WARNING **: Failed to load plugin '/usr/lib/gstreamer-0.10/libgstffmpeg.so': /usr/lib/x86_64-linux-gnu/libavcodec.so.53: undefined symbol: lame_set_VBR_quality
Cannot connect to server socket err = No such file or directory
Cannot connect to server socket
jack server is not running or cannot be started

How can I solve the lame_set_VBR_quality problem?

Answer 1

there are two unrelated problems reported in output:

gstffmpeg

on startup, gstreamer scans for available plugins and tries to load them. among these plugins is the file /usr/lib/gstreamer-0.10/libgstffmpeg.so .

it seems that you have installed incompatible libraries (eg your gstreamer "ffmpeg" plugin depends on a different version of libavcodec.so ), so the ffmpeg-plugin set cannot be loaded.

the problem is not really related to gstreamer itself, but rather to the way how you installed those libraries.

since linux-distributions usually are all about resolving inter-package dependencies (so that you can never install a package "foo-2.0" that depends on "bar-0.4" if you only have "bar-0.1" installed), i guess that you have added some non-official unsupported 3rd-party repositories (eg on debian, a common source of headaches is the deb-multimedia repository; other distros will have others).

if all libraries installed are from the official repository of your distro, chances are that you hit a bug in the packaging and you should report the bug to the maintainers of the package(s) providing the faulty libraries.

jack

the other "error" about jack not being able to start, is because the pipeline you are using uses the generic playbin2 element, which probes for available playback backends. while doing so, it also tries to connect to a running jack -server, fails to do so and (hopefully) falls back to another available audio framework.

Answer 2

One additional comment on the audio side. Check whether something simple as gst-launch audiotestsrc ! autoaudiosink works. Try again with pulsesink or alsasink instead of autoaudiosink. These 2 would be tried before considering jack.