GNOME Bugzilla – Bug 349781
Simultaneous playback/record not synced properly and playback starts after alsasrc capture offset
Last modified: 2009-08-12 19:12:32 UTC
Please describe the problem: I have a pipeline that plays back audio as well as recording audio (the recorded audio is not played back). The problem is that the recorded audio has a noticable lack of sync with the playback audio. As an example, if my playback audio has a solid beat and when I record I tap the mic to the beat, the recorded audio beats are a little late and not synced. This can be demonstrated in Jokosher at the moment (0.1 and HEAD). I spoke to thaytan about this and he thinks it could be that the alsasrc has a clock for the pipeline, but it needs to capture samples before the clock can sync with the playback bin. The problem is that the playback bin starts playing back ater this initial capture period, thus creating a delay. GStreamer should really auotmatically account for this offset. Steps to reproduce: 1. 2. 3. Actual results: Expected results: Recorded audio should play back in sync with the original playback audio. Does this happen every time? Yes. Other information:
Jono, are you still seeing this issue ? There's been a *lot* of fixes in that regards in the past 30months.
I just tested it and its hard to tell. The bug says they are "a little late". I dunno how little is little, but in my testing beats are its pretty close. I would say any difference in the second recorded track its more due to my lack of rhythm than Gstreamer. Plus there might be some additional lag being introduced between microphone, onboard microphone, alsasrc input, or even pulseaudio output. Not much point in asking Jono to reproduce. As far as I know he hasn't used Jokosher in over a year. Might as well just close this bug.
Closing this bug report as no further information has been provided. Please feel free to reopen this bug if you can provide the information asked for. Thanks!