advice on live capture to disk

[John Bazik]

>   What version of GStreamer are you using ? What does your pipeline look
> like ? Do you get any warnings (GST_DEBUG=2) ? What are those "weavy
> artifacts" you mention ?

Here's the last one I ran yesterday:

gst-launch-1.0 -e\
        decklinksrc mode=17 connection=1 name=raw\
        raw.videosrc !\
                queue max-size-bytes=104857600 !\
                videorate ! video/x-raw,framerate=30/1 !\
                videoconvert !\
                avenc_huffyuv buffer-size=104857600 !\
                queue max-size-bytes=104857600 ! mux.\
        matroskamux name=mux !\
                filesink buffer-mode=full buffer-size=104857600\
                        location=/var/tmp/live$$.mkv

Okay, I lied - this one works.  I was dropping frames writing via NFS,
so that's my problem (unfortunately, I do need to do that).

I'd prefer to save a smaller file, though, so here's the last x264
pipeline I tried:

gst-launch-1.0 -e\
        decklinksrc mode=17 connection=1 name=raw\
        raw.videosrc ! queue !\
                videorate ! video/x-raw,framerate=30/1 !\
                videoconvert !\
                x264enc speed-preset=medium ref=4 quantizer=20 !\
                queue ! mux.\
        raw.audiosrc ! queue ! audioconvert ! audio/x-raw,format=S16LE !\
                voaacenc ! queue ! mux.\
        qtmux name=mux !\
                filesink location=/var/tmp/live$$.mov

My source is 720p, UYVY, 60000/1001fps.  Gstreamer version is 1.2.4.

Speed-presets slower than medium drop frames.  The warnings come
from decklinksrc.  This looks good, but in a large white field (a
whiteboard), I see an irregular mosaic pattern emerge, grey-on-white,
and start to ripple, then it clears and starts over, continuously.
Cycles about every 8 seconds (240 frames).

That one runs at about 350% cpu (six cores).  The processor is an AMD
Phenom II, running at 3.3GHz with 8G of memory.

John