spotifyaudiosrc: Support custom bitrate
Spotify supports three different bitrates for audio streaming (96, 160 and 320 kbit/s). librespot supports them as well and thus, I have added a parameter to the plugin to allow the user to select the desired audio quality.
However, gstreamer does not respect the default value (gst-inspect
just shows an empty string). The same problem occurs with the other parameters, but not with some of the other plugins (played around with rgb2gray and gst-inspect
prints the default values as expected). Any hints on what could cause this problem?