beta 4 higher cpu than beta 3 + high cpu usage spikes when looping

[hamoid]

I wrote a simple vj program: https://gitlab.com/hamoid/processing-mini-vj

In my program I load a background image and two looping HD videos, then open top in a terminal.

With beta 3 the cpu stays at around 100% (I guess that's 1 core).

With beta 4 the cpu stays at around 135%, and periodically there are spikes of 400% to 600% cpu. When that happens, the program keeps running but the videos are frozen (they stop updating). After about 1 second of freezing, the program continues to run normally and cpu goes back to 135%.

I suspect (but did not verify) that the spikes happen when the the videos reach the end and jump to the beginning (in loop mode). This periodical freezing does not happen in beta 3.

I can provide the videos if it helps debug. They are about 30 ~ 50 Mb and about 20 to 40 seconds long.

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'MAH05762-sun-reflection-on-tree.MP4':
  Metadata:
    major_brand     : MSNV
    minor_version   : 19595376
    compatible_brands: MSNVmp42isom
    creation_time   : 2016-06-21T17:46:37.000000Z
  Duration: 00:00:31.68, start: 0.000000, bitrate: 12143 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1440x1080 [SAR 4:3 DAR 16:9], 12013 kb/s, 25 fps, 25 tbr, 25k tbn, 50 tbc (default)
    Metadata:
      creation_time   : 2016-06-21T17:46:37.000000Z
      handler_name    : Video Media Handler
      encoder         : AVC Coding
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 127 kb/s (default)
    Metadata:
      creation_time   : 2016-06-21T17:46:37.000000Z
      handler_name    : Sound Media Handler

Now that I think about it, maybe I should I split this into two issues?