Collecting Information

VP8 vs. H.264

5/20/2010 | Comments: 1

There is a very interesting article about Google's video codec VP8 written by an x264 developer called Jason Garrett-Glaser (aka Dark Shikari) which you can completely read on:

The title is "The first in-depth technical analysis of VP8".

Here are some central statements out of it:

  • Verdict on Intra Prediction: Slightly modified ripoff of H.264. Somewhat worse than H.264 due to omission of i8×8.
  • Verdict on Inter Prediction: Similar partitioning structure to H.264. Much weaker referencing structure. More complex, slightly better interpolation filter. Mostly a wash — except for the lack of B-frames, which is seriously going to hurt compression.
  • Verdict on Transform: Similar to H.264. Slower, slightly more accurate 4×4 transform. Improved DC transform for luma (but not on chroma). No 8×8 transform. Overall, worse.
  • Verdict on Quantization: Lack of well-integrated adaptive quantization is going to be a killer when the time comes to implement psy optimizations. Overall, much worse.
  • Verdict on Entropy Coding: I’m not quite sure here. It’s better in some ways, worse in some ways, and just plain weird in others. My hunch is that it’s probably a very slight win for H.264; non-adaptive arithmetic coding has to have some serious penalties. It may also be a hardware implementation problem.
  • Verdict on Loop Filter: Definitely worse compression-wise than H.264’s due to the lack of adaptive strength. Especially with the “fast” mode, might be significantly faster. I worry about it being too blurry.
  • VP8 is simply way too similar to H.264: a pithy, if slightly inaccurate, description of VP8 would be “H.264 Baseline Profile with a better entropy coder”.
  • Before I tear the encoder apart, keep in mind that it isn’t bad. In fact, compression-wise, I don’t think they’re going to be able to get it that much better using standard methods.
  • The encoder and decoder share a staggering amount of code. This means that any bug in the common code will affect both, and thus won’t be spotted because it will affect them both in a matching fashion.
  • Google has chosen Matroska for their container format.

I definitely recommend reading at least the "Addendum C: Summary for the lazy".


sflhaBek   1/ 3/2020

cbd oil cbd distillery cbd oil cbd oil walmart cbd oil from hemp cbd oil online amazon cbd oil

hemp cbd oil cbd oil cbd oil organic cbd oil cbd oil hemp cbd oil cbd oil yaa health

Leave Comment