scripts and compressing video files to these formats.
The components of the Helix YUV Codecs pack are an I420 VFW Compressor/Decompressor and an YV12 VFW Compressor/Decompressor. I420 is YV12 with the chroma planes swapped.
Both tools decode I420 and YV12. They are almost identical, as they accept common input formats and provide lossless compression. The difference is that i420vfw.dll encodes to I420, while yv12vfw.dll encodes to YV12. With the Helix YUV Codecs you can obtain fast color conversions to the most popular RGB formats, YUV2 and I420 and YV12 when requested.
A limitation for these tools is that width has to be a multiple of 4, and height needs to be a multiple of 2.
VfW codecs are necessary for playing and editing in VirtualDub
and other similar applications.
The aim of the Helix YUV Codecs was to provide a better alternative to MS H.263, which couldn’t handle dimension multiple of 15 or exceeding 352 x 288. On the other hand, the Helix YUV Codecs can handle multiples of 4.
Unlike XviD and MS H.263, the Helix YUV Codecs can convert both to and from I420 and YV12. The codec responsible for handling each format is selected automatically.
These codecs have been discontinued, but they may still be helpful for those using older machines and older versions of codecs and media players.
Other actions performed by this codec are handling the output of