Dears, I got error when I try to play audio file (.wav) to usb audio device. file source is usb storge, i use the command to play audio: gst-launch-0.10 filesrc location=/var/tmp/usb/sda1/audio_src/audio_src_48k_le.wav ! wavparse ! audioconvert ! alsasink device="hw:0,0"& EROLLING ... ERROR: from element /GstPipeline:pipeline0/GstWavParse:wavparse0: Internal data flow error. Additional debug info: gstwavparse.c(2110): gst_wavparse_loop (): /GstPipeline:pipeline0/GstWavParse:wavparse0: streaming task paused, reason not-linked (-1) ERROR: pipeline doesn't want to preroll. Setting pipeline to NULL ... Freeing pipeline ... Also, when i try to play audio file via Rygel renderer , it is fail ,too. the reason is the same as gst-launch, what is "reason not-linked (-1)"? Does any one have idea? But when i try to play audio file by "aplay" , it is OK. is there some thing wrong in gstreamer?