BT20

From MultimediaWiki
Jump to navigation Jump to search
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.

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.