July 10,2020

ingest.py has a new parameter: --src

it can be used instead of these 6:
```
  --video-source {dv,hdv,udp_h264,hdmi2usb,blackmagic,ximage,png,file,test,spacescope}
  --video-attribs VIDEO_ATTRIBS
  --video-elements VIDEO_ELEMENTS
  --audio-source {dv,hdv,file,alsa,pulse,blackmagic,test}
  --audio-attribs AUDIO_ATTRIBS
  --audio-elements AUDIO_ELEMENTS
```

The above 6 parameters are used to construct a gst pipeline string, --src takes that same string as a parameter.  or some other string that can't be constructed, like for a simple logitech webcam:

`ingest.py --src "v4l2src ! queue ! videoconvert ! videorate ! videoscale ! {videocaps} ! mux. audiotestsrc wave=ticks freq=330 ! {audiocaps} ! queue ! matroskamux name=mux"'

{videocaps} and {audiocaps} come from voctocore, or they can be overridden with static values, not sure when one would need that.
