audiosink causes video framerate to drop to undetermined level (not 30fps)

Marco Ballesio gibrovacco at
Sat May 28 10:50:35 PDT 2011


I'm not an expert of Ruby, btw there are a few sanity checks you may run
(see below)..

On Fri, May 20, 2011 at 11:57 PM, Matt McIntyre <matt at>wrote:

> That's the best I can determine so far at least by removing it.
>  I'm writing a program using the ruby-gnome2 gstreamer bindings that
> captures video (v4l) and audio (standard soundcard), displays the video
> onscreen, loops the audio back out for monitoring, and records to disk using
> avi/wav.  I'll be glad to provide the code, but in consideration of
> everyone's time I'll provide the gstreamer pipeline I'm first since I'm sure
> its something simple I'm not doing right.
> My pipeline is separated into several bins and looks like this:
> AudioBin: (source ghost pad to the tee src)
> autoaudiosrc ! audio/x-raw-int ! level ! tee name=audiotee
> audiotee ! autoaudiosink
> VideoBin: (source ghost pad to the tee src)
> v4l2src ! video/x-raw-yuv, format=(fourcc)YUY2,
> framerate=(fraction)30000/1001, width=(int)720, height=(int)480 ! videorate
> ! tee name=videotee
> videotee ! xvimagesink

here you're dealing with raw 720x480 YUY2 @ 30fps.. I would run "top" and
give a look at the CPU usage.

> RecorderBin: (audio and video sink pads linked to the audio queue and video
> queue respectively)
> queue name=audioqueue ! avimux name=mux
> queue name=videoqueue ! jpegenc ! mux ! filesink
> AudioBin ! VideoBin ! RecorderBin
running the pipelines after setting GST_DEBUG=2 (or more) will give you some

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