BT20

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According to http://fourcc.org/ , BT20 is a "Codec optimised for realtime compression of YUV images." The binary decoder answers to the filename btvvc32.drv.

Strings seen in AVI file headers include:

  • C:\PROGRAM FILES\EZCAP\CAPTURE.EXE -AVICAP32- MSVIDEO: AVerMedia InterCam Video Capture Driver, Version: 4.1.8.6
  • C:\PROGRAM FILES\GV-VCP VIDEORECORDER\GVCAP.EXE -AVICAP32- MSVIDEO: Brooktree Bt848 Capture Driver, Version: 2.2.223.0

Video frame payloads begin with the 4 ASCII characters 'BTIC'.

This is a simple intra-only delta compression codec. It codes UYVY data using vertical prediction, 6-bit deltas and an additional compression pass that removes repeats and replaces certain delta pairs with their codebook index.