Kostya's Boring Codec World

So I’ve finally written a decoder for ClearVideo in NihAV and it works semi-decently.

Here’s a twentieth frame of basketball.avi from the usual sample repository. Only the first frame was intra-frame, the rest are coded with just the transforms (aka “copy block from elsewhere and change its brightness level if needed too”).

As you can see there are still serious glitches in decoding, especially on bottom and right edges but it’s moving scene and most of it is still good. And the standard “talking head” sample from the same place decodes perfectly. And RealMedia sample is decoded acceptably too.

Many samples are decoded quite fine and it’s amazing how such simple method (it does not code residue unlike other video codecs with interframes!) still achieves good results at reasonable (for that time) bitrate.

Hopefully there are not so many bugs in my implementation to fix so I can finally move to RealVideo 3 and 4. And then probably to audio codecs before RealVideo 6 (aka RealMedia HD) because it needs REing work for details (and maybe wider acceptance). So much stuff to procrastinate!

Update: I did MV clipping wrong, now it works just fine except for some rare glitches in one RealMedia file.

This entry was posted on Saturday, February 3rd, 2018 at 2:45 pm and is filed under Various Video Codecs. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.