[x264-devel] x264 Development Newsletter: Vol 15

[Jason Garrett-Glaser]

This is the fifteenth x264 development newsletter. This is a regular
email containing updates on fixes and improvements in the most recent
x264 push, along with updates on what's coming next.  Previous
versions can be found in the mailing list archives.

Fixes:

Make open-gop work correctly with no-psy (--tune psnr and ssim).

Force pic-struct with blu-ray-compat + fake-interlaced.

Add support for compiling against libav(codec|format) version 53.

Fix decoder desync with positive chroma qp offset and zones.

Support the most recent gpac versions.

Fix VFR MB-tree to work as intended; improves quality with FPSs
significantly larger or smaller than 25.

Improvements:

Validate input parameters more carefully and cleanly; fix a number of
bugs and/or cosmetic issues relating to parameter validation warnings.

Clean up CABAC residual writing and optimize it further.

Speed up x264_encoder_open by a factor of ~10, saving about a hundred
million clock cycles, by avoiding redundant log2f calls.

Precalculate CABAC initialization contexts: slightly faster encoding
with lots of slices, at the cost of slightly more init time.

Upcoming:

--device and automatic --level restriction support is in the works, as
part of Google Code-In.  The patch is done, but needs review.

A per-option help system is in the works, as part of Google Code-In.
The patch is done, but needs editing of the help entries.

Adaptive MBAFF development is **done** and review is done -- now we're
doing performance optimizations.

x262 is under development: a best-in-class MPEG-2 encoder built using
the x264 framework.  Both P and B-frames are done and working.

xvp8 is under development: a best-in-class VP8 encoder built using the
x264 framework.

Google Summer of Code is coming soon: Trellis ME and H.264/MVC support
are the two projects.  Wish the students luck!

Jason Garrett-Glaser

The x264 Team