Deterministic rendering

[niklaspandersson]

Adds deterministic rendering

• Introduce the SCHEDULE command suite to schedule commands that will be recorded in non-realtime.
• SCHEDULED commands are invoked on a virtual channel, unique for each SCHEDULE session. Use the $ channel placeholder to schedule commands in the active schedule session
• Producers get to take as long as they need to produce a frame, and the channel doesn't tick until all registered producers have delivered a frame
• Support for virtual time in the html producer, which means that caspar explicitly ticks cef with the correct amount of time between frames
  • video- and audio- elements are not supported by this
• Introduce the 'shutdown-on-eof' setting, which enables workflows where a batch of SCHEDULE commands are piped in to a fresh casparcg process, which then terminates when the recording is completed

To get started:

1. create a config without any channels
2. set configuration.html.wait-for-fp=true and configuration.html.enable-virtual-time=true
3. set configuration.shutdown-on-eof=true and configuration.shutdown-on-eof-grace-ms=500
4. Create a text-file with schedule commands. For example:

   SCHEDULE BEGIN 1080p5000 ADD FILE record.mp4 -codec:a aac -b:a 128k -filter:a pan=stereo|c0=c0|c1=c1 -codec:v libx264 -filter:v format=yuv420p
   SCHEDULE FRAME 0 PLAY $-10 2_h264_hdr
   SCHEDULE FRAME 0 CG $-23 ADD 1 infobox/index 1 "<templateData>eyJoZWFkbGluZSI6ImF3ZGF3ZGF3ZHdhZHdhZHdhZHdhZGF3Iiwic3VidCI6IiIsImhvc3QxIjoiIiwiaG9zdDIiOiIiLCJlbW5lIjoic2Vmc2VmIiwiZW1uZUNvbG9yIjoidG9tIiwiaGlzdG9yeSI6bnVsbCwiX3ZmIjoibnVsbCIsIl9hZiI6ImFudWxsIiwiX2R1cmF0aW9uIjpudWxsLCJfc2NhbGVfbW9kZSI6ImZpdCIsIl9zZWVrIjowfQ==</templateData>"
   SCHEDULE FRAME 0 MIXER $-23 OPACITY 0.5
   SCHEDULE FRAME 100 MIXER $-23 OPACITY 1 100
   SCHEDULE FRAME 200 PLAY $-10 4k MIX 50
   SCHEDULE FRAME 300 CG $-23 STOP 1
   SCHEDULE END 350 COMMIT
   

5. run casparcg casparcg-record.config < schedule.txt. It should record 350 frames to record.mp4 and terminate when ready.

Leaving this as draft until more tests has been performed