(copied from VP9)
The one pass VBR mode selects a Q range based on a
moving average of recent Q values. This calculation
should have been excluding arf overlay frames as these
are usually coded at the highest allowed value. Their
inclusion skews the average and can cause it to drift
upwards even when the clip as a whole is undershooting.
As such it can undermine correct adaptation of the allowed
Q range especially for easy content.
Change-Id: I9e12da84e12917e836b6e53ca4dfe4f150b9efb1
This change has been imported from VP9 and
alters the nature and use of exhaustive motion search.
Firstly any exhaustive search is preceded by a normal step search.
The exhaustive search is only carried out if the distortion resulting
from the step search is above a threshold value.
Secondly the simple +/- 64 exhaustive search is replaced by a
multi stage mesh based search where each stage has a range
and step/interval size. Subsequent stages use the best position from
the previous stage as the center of the search but use a reduced range
and interval size.
For example:
stage 1: Range +/- 64 interval 4
stage 2: Range +/- 32 interval 2
stage 3: Range +/- 15 interval 1
This process, especially when it follows on from a normal step
search, has shown itself to be almost as effective as a full range
exhaustive search with step 1 but greatly lowers the computational
complexity such that it can be used in some cases for speeds 0-2.
This patch also removes a double exhaustive search for sub 8x8 blocks
which also contained a bug (the two searches used different distortion
metrics).
For best quality in my test animation sequence this patch has almost
no impact on quality but improves encode speed by more than 5X.
Restricted use in good quality speeds 0-2 yields significant quality gains
on the animation test of 0.2 - 0.5 db with only a small impact on encode
speed. On most natural video clips, however, where the step search
is performing well, the quality gain and speed impact are small.
Change-Id: Iac24152ae239f42a246f39ee5f00fe62d193cb98
Fix copied over from VP9 master to VP10 master.
Do not reset the alt ref active flag when overlaying the middle
arf(s) of a multi arf group.
Change-Id: I1b7392107e7c675640d5ee1624012f39cc374c58
The range_check is not used because the bit range
in fdct# is not correct. Since we are going to merge in a new version
of fdct# from nextgenv2, we won't fix the incorrect bit range now.
Change-Id: I54f27a6507f27bf475af302b4dbedc71c5385118
Remove delta index 254 from probability remapping and subexp coding.
Saves 1-bit when the delta index is 129.
Change-Id: I88aba565fc766b1769165be458d2efd3ce45817e
The custom LCG is based on the POSIX recommend constants for a 16-bit
rand(). This implementation uses less computation than typical standard
library procedures which have been extended for 32-bit support, is
guaranteed to be reentrant, and identical everywhere.
Change-Id: I3140bbd566f44ab820d131c584a5d4ec6134c5a0
Ref: http://pubs.opengroup.org/onlinepubs/9699919799/functions/rand.html
Add the row and column index to the argument list of unit functions
called by foreach_transformed_block wrapper. This avoids the
repeated internal parsing according to the block index.
Change-Id: Ie7508acdac0b498487564639bc5cc6378a8a0df7
Added optimization of the 8 bit assembly quantizer routines. This makes
these functions up to 100% faster, depending on encoding parameters.
This patch maskes the encoder faster in both the high bitdepth and 8bit
configurations. In the high bitdepth configuration, it effects profile 0
only.
Based on my profiling using 1080p input the net gain is between 1-3% for
the 8 bit config, and around 2.5-4.5% for the high bitdepth config,
depending on target bitrate. The difference between the 8 bit and high
bitdepth configurations for the same encoder run is reduced by 1% in all
cases I have profiled.
Change-Id: I86714a6b7364da20cd468cd784247009663a5140
Some more testing of this patch would probably be useful, but I
think the basics of it should work fine now.
See issue 1035.
Change-Id: I4a36d58f671c5391cb09d564581784a00ed26245
This experiment allows using full above/right edges for all transform
sizes whenever available (for d45/d63), and adds bottom/left edges for
d207.
See issue 1043.
Change-Id: I5cf7f345e783e8539bb6b6d2c9972fb1d6d0a78b
This has various benefits:
- simplify implementations because we don't have to switch between
multiple probability tables depending on frametype
- allows fw subexp and bw adaptivity for partitions/uvmode in keyframes
See issue 1040 point 5.
Change-Id: Ia566aa2863252d130cee9deedcf123bb2a0d3765
Locate them (code-wise) in frame_context, and have them be updated
as any other probability using the subexp forward and adaptive bw
updates.
See issue 1040 point 1.
TODOs:
- real-world default probabilities
- why is counts sometimes NULL in the decoder? Does that mean bw
adaptivity updates only work on some frames? (I haven't looked
very closely yet, maybe this is a red herring.)
Change-Id: I23b57b4e5e7574b75f16eb64823b29c22fbab42e
Account for rounding in distortion calculation in k-means;
carry out rounding before duplicates removal of base colors;
replace numbers with macros;
use prefix increment.
Slight coding gain (<0.1%) on screen_content testset.
Change-Id: Ie8bd241266da6b82c7b2874befc3a0c72b4fcd8c
This actually has no effect whatsoever, since the input MVs themselves
are clamped by clamp_mv_ref() already, which is significantly more
restrictive in its bounds.
Change-Id: I4a3a7b2b121ee422c56428c2a12d930c3813c06e
We only write EOSB tokens if we write tokens (i.e. not for skip blocks),
and we write EOSB tokens per-plane instead of per block.
Change-Id: I8d7ee99f8ec50eb7ae809f9f9282c1c91dbf6537
Add palette mode for keyframe luma channel. Palette mode is enabled
when using "--tune-content=screen" in encoding config parameters.
on screen_content testset: +6.89%
on derlr : +0.00%
Design doc (WIP):
https://goo.gl/lD4yJw
Change-Id: Ib368b216bfd3ea21c6c27436934ad87afdaa6f88
We have historically added new bits to cat6 whenever we added a new
transform size (or bitdepth, for that matter). However, we have
always coded these new bits regardless of the actual transform size,
which means that for smaller transforms, we code bits that cannot
possibly be set. The coding (quality) impact of this is negligible,
but the bigger issue is that this allows creating bitstreams with
coefficient values that are nonsensible and can cause int overflows,
which then de facto become part of the bitstream spec. By not coding
these bits, we remove this possibility.
See issue 1065.
Change-Id: Ib3186eca2df6a7a15ddc60c8b55af182aadd964d
