[x264-devel] x264 Development Newsletter: Vol 17

[Jason Garrett-Glaser]

This is the seventeenth 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:

Fix automatic bitstream reallocation with slice-max-size + MBAFF.

Fix a bug where VBV could target a frame size larger than the MinCR
limit, causing weird results.

Fix a crash when combining VBV and per-frame QP forcing (not like you
should be doing this anyways, as it's nonsensical).

Fix a VBV bug where the first and last row got zero SATD scores.

Make --profile main and baseline force off CQMfiles, not just explicit CQMs.

Improvements:

Inline emms instructions to avoid an extra function call.

AVX version of mbtree_propagate: 20-30% faster on Sandy Bridge.

Updates to the resize filter: update for newer swscale API and various
other fixes.

Make ratecontrol_mb less slow: due in large part to redundant
qp/qscale conversions, it was using up to ~3% of time in extreme
cases.

Improve MBAFF row VBV ratecontrol: revert to a simpler and cleaner algorithm.

Fix various issues with VBV and threads to eliminate a race condition
and use of uninitialized values.  Should make valgrind happier.

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.

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.

Google Summer of Code is in progress: Trellis ME and H.264/MVC support
are the two projects.

4:4:4 decoding support is finished for libavcodec: 4:4:4 encoding for
x264 is in progress.

Jason Garrett-Glaser

The x264 Team