Sometimes you get obscure error messages like:
Error: gst-stream-error-quark: Internal data stream error......
This message is not very informative, however you can get more data by setting Gstreamer’s debug level.
To set debug level to all plugins set this environment variable:
export GST_DEBUG="*:3"
Now rerun and hopefully you’ll get more informative data.
To disable debug level unset this variable.
Happy debugging 