2012-01-27 v1.0.0 "Duclair"
Our fourth named release, focused on performance and features related to
real-time encoding. It also fixes a decoder crash bug introduced in
v0.9.7, so all users of that release are encouraged to upgrade.
- Upgrading:
This release is ABI incompatible with prior releases of libvpx, so the
"major" version number has been bumped to 1. You must recompile your
applications against the latest version of the libvpx headers. The
API remains compatible, and this should not require code changes in most
applications.
- Enhancements:
This release introduces several substantial new features to the encoder,
of particular interest to real time streaming applications.
Temporal scalability allows the encoder to produce a stream that can
be decimated to different frame rates, with independent rate targetting
for each substream.
Multiframe quality enhancement postprocessing can make visual quality
more consistent in the presence of frames that are substantially
different quality than the surrounding frames, as in the temporal
scalability case and in some forced keyframe scenarios.
Multiple-resolution encoding support allows the encoding of the
same content at different resolutions faster than encoding them
separately.
- Speed:
Optimization targets for this release included the decoder and the real-
time modes of the encoder. Decoder speed on x86 has improved 10.5% with
this release. Encoder improvements followed a curve where speeds 1-3
improved 4.0%-1.5%, speeds 4-8 improved <1%, and speeds 9-16 improved
1.5% to 10.5%, respectively. "Best" mode speed is consistent with the
Cayuga release.
- Quality:
Encoder quality in the single stream case is consistent with the Cayuga
release.
- Bug Fixes:
This release fixes an OOB read decoder crash bug present in v0.9.7
related to the clamping of motion vectors in SPLITMV blocks. This
behavior could be triggered by corrupt input or by starting
decoding from a P-frame.