BIK/en
BIK files are the video files created using Bink, as part of Epic Video Tools. The startup video that plays on all Valve games, and third-party games (since the Source 2007 update) is a .bik file. They are also used in the menu backgrounds and the elevator screens in
Portal 2. Prior to Bink being added to Source, previous games or older version of those games uses AVI file instead. One game,
Vampire The Masquerade - Bloodlines, which runs on Source 2004, was the first Source game to utilize Bink video for it's startup video.
By today standards, Bink (retroactively Bink version 1.0), suffers from large file sizes while having slighting lower quality, and it's was much more complicated when it's come to converting files, such as AVI or MP4 (with deprecated QuickTime application) to BIK that may ended up causing audio/video desync or other issues. Due to these issues along with many others, Bink 2 was created, which have massive improvement over Bink 1. Furthermore, there are alternatives to Bink video, such as Google WebM, which is open-source and completely free.
In some Mac port of Source engine games, it may instead use QuickTime's MOV video file.
In all games using the Titanfall engine branch, the engine has been upgraded to use Bink 2, which uses .bk2 file format instead and have more features, support multi-core rendering and HDR, full color range, and better video quality than Bink 1 had.
In the newer version of CS:GO engine branch (which uses Panorama) and newer version of
Hunt Down the Freeman, all
Source 2 games, as well as
Strata Source, it is replaced by WebM.
