Skip to content

v4.1.0

Choose a tag to compare

@theoladune theoladune released this 19 Sep 14:51
· 14 commits to main since this release
d0f7ac1

🔮 Cool-chic 4.1.0: Revisiting temporal prediction! 🔮

Cool-chic 4.1 focuses on video coding, improving particularly the temporal
prediction through better and lighter sub-pixel motion compensation. This
release is linked to the following paper: Efficient Sub-pixel Motion Compensation in Learned Video Codecs, Ladune et al..

  • Replace 2-tap bilinear filtering with sinc-based 8-tap filters
  • Decode motion fields at 1/4 of the frame resolution for lighter decoding complexity
  • Improved video compression performance: -23.6% rate versus Cool-chic 4.0
  • Decrease motion-related complexity by 45%, from 391 to 214 MAC / decoded pixel

Check-out the release history to see previous versions of Cool-chic.

This release does not affect image compression performance which remains identical to v4.0.0

Video compression performance

The Cool-chic page provides comprehensive video rate-distortion results.

Random access results (intra period 32)

Sequence BD-rate of Cool-chic 4.1.0 against [%] Decoding complexity
HEVC (HM 16) HEVC (x265-medium) AVC (x264-medium) Cool-chic 4.0 MAC / pixel Frame rate [fps]
C-BasketballDrill +30.8 -5.2 -29.5 -17.5 639 13.3
C-BQMall +77.1 +16.6 -6.0 -21.1 639 13.2
C-PartyScene +28.3 -15.1 -39.2 -39.1 639 12.9
C-RaceHorses +79.6 +17.4 +8.6 -16.8 639 12.1
Average +54.0 +3.4 -14.0 -23.6 639 12.9

Image compression performance

The Cool-chic page provides comprehensive image rate-distortion results.

BD-rate of Cool-chic 4.1 vs. [%] Avg. decoder complexity
Cheng ELIC C3 HEVC (HM 16) VVC (VTM 19) MAC / pixel CPU Time [ms]
kodak -4.2 % +7.5 % -4.3 % -17.2 % +3.4 % 1303 74
clic20-pro-valid -13.2 % -0.2 % -1.3 % -25.1 % -2.3 %
1357 354
jvet (BCDEF) / / / -18.3 % +18.6 % 1249 143
jvet (class B) / / / -9.9 % +20.7 % 1300 282
jvet (class C) / / / -16.1 % +9.2 % 1289 69
jvet (class D) / / / -12.4 % +9.6 % 948 18
jvet (class E) / / / -6.2 % +27.8 % 1347 125
jvet (class F) / / / -31.8 % +20.6 % 1249 182