alsasink, sync=false and pipeline clocking

[Chris Tapp]

I've been having audio problems (glitches, dropouts) when using pipelines of the form:

  playbin uri=<live-mpegts-stream> audio-sink="alsasink"

It appears that setting sync=false in the alsasink stops the glitches, so I suspect they're being caused by a clock mismatch between the pipeline clock and the (implied) clock from the mpegts stream.

However, running with sync=false means that, as expected, the audio and video drift out of step with each other. How can I maintain a reasonable level of sync between the audio and video? I think this has something to do with the discont-wait, drift-tolerance and alignment-threshold properties of alsasink, but I can't find a set of values that work that well. Is there a document somewhere that explains exactly what these parameters do? I've looked at the output of `gst-inspect alsasink`, but that doesn't explain how these parameters are related.

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Chris Tapp
opensource at keylevel.com
www.keylevel.com