As mensagens de erro não são úteis para diagnosticar o que está quebrado aqui:
O que pode ser feito para fazer o Pitivi e o gstreamer trabalharem melhor juntos?
Devo desistir do Pitivi e usar outra ferramenta?
ERROR [15963] [0x7fb986aed700] "<Pipeline at 0x22333d0>" pipeline Sep 18 19:31:14 _errorObject: error from /GstPipeline:pipeline1/GstBin:bin1/GnlComposition:gnlcomposition3/GnlSource:gnlsource: AudioTestSourceFactory3/GstBin:bin5/GstAudioTestSrc:real-audiotestsrc (__main__.GstAudioTestSrc): GStreamer encountered a general stream error. (gstbasesrc.c(2507): gst_base_src_loop (): /GstPipeline:pipeline1/GstBin:bin1/GnlComposition:gnlcomposition3/GnlSource:gnlsource: AudioTestSourceFactory3/GstBin:bin5/GstAudioTestSrc:real-audiotestsrc:
streaming task paused, reason not-negotiated (-4)) (/usr/lib/pitivi/python/pitivi/log/loggable.py:30)