The API is not final yet and can be changed. Actual layout of
uncompressed frame part will be finalized later. Right now moving
clr_type, error_resilient_mode, refresh_frame_context,
frame_parallel_decoding_mode from first compressed partition to
uncompressed frame part.
Change-Id: I3afc5d4ea92c5a114f4c3d88f96858cccc15b76e
Cleans up the experiment. Actually uses reduced counts for backward
updates, and reduced number of probabilities in the context.
No change in bitstream when the experiment is on.
Between expt on and off:
derfraw300 is down only -0.062% (which is better than when expts
were run previously).
Change-Id: I55285a049a0c22810bdb42914212ab5a4f8521b5
The new code is 0x49, 0x83, 0x42
There is nothing particularly special about this code bitstream wise.
Its derivation is the word "sync" coded using 4x6bit alphabetic indices.
Change-Id: Ie2430a854af32ddc5a5c25a6c1c90cf6497ba647
The recursive partition type search is enabled down to 4x4, 4x8 and
8x4, followed by the corresponding rate-distortion optimization for
the per-partition encoding mode decisions.
The bit-stream writing/reading synchronized in supporting the
rectangular partition of 8x8 block.
This provides above 1% coding performance gains on derf.
To do next:
1. re-design the rate-distortion loop for inter prediction below 8x8.
2. re-design the rate-distortion loop for intra prediction below 4x4.
3. make the loop-filter aware of rectangular partition of 8x8 block.
4. clean the unused probability models.
5. update default probability values.
Change-Id: Idd41a315b16879db08f045a322241f46f1d53f20
Replace vp9_kf_default_bmode_counts structure with
direct default probabilities. The probability structure is
smaller and it removes the need to specify in the bitstream
how to convert the counts to probabilities.
Note that I have concerns still about the size and value of
the large intra mode context. This may cause problems for
HW but it also means we rely heavily on reverse update as
forwards update of a structure this size is problematic. I
intend to review this more generally in the next few days to
see if we can come up with a competitive solution that does
not rely on such a large context.
Change-Id: I0a36071079d5d26a57ab0e9fbf91af4199aa7984
Replace mi_width/height_log2 with b_width/height_log2 in partition
type parsing at bit-stream writing stage. This allows parsing
resolution at 4x4 block level and makes the 4x4/4x8/8x4 partition
coding consistent with other superblock types.
Change-Id: I7db3617ea042e0db2dc898999b0c323bff91a22f
This patch creates a new inter mode contest that avoids
a dependence on the reconstructed motion vectors from
neighboring blocks. This was a change requested by
a hardware vendor to improve decode performance.
As part of this change I have also made some modifications
to stats output code (under a flag) to allow accumulation of
inter mode context flags over multiple clips
Some further changes will be required to accommodate the
deprecation of the split mv mode over the next few days.
Performance as stands is around -0.25% on derf and
std-hd but up on the YT and YT-HD sets. With further tuning
or some adjustment to the context criteria it should be
possible to make this change broadly neutral.
Change-Id: Ia15cb4470969b9e87332a59c546ae0bd40676f6c
Combining encode_nmv_component with encode_nmv_component_fp
and read_nmv_component with read_nmv_component_fp. Bitstream is slightly
changed (only the order of bits), here are the results on test sets:
stdhd: +0.047, yt: -0.038, derf: +0.001, hd: -0.011.
Change-Id: I1be312e976796df78ca63368702d0ee19f2b8c50
This commit allows the rate-distortion optimization recursion
at encoder to go down to 4x4 block size. It deprecates the use
of I4X4_PRED and SPLITMV syntax elements from bit-stream
writing/reading. Will remove the unused probability models in
the next patch.
The partition type search and bit-stream are now capable of
supporting the rectangular partition of 8x8 block, i.e., 8x4
and 4x8. Need to revise the rate-distortion parts to get these
two partition tested in the rd loop.
Change-Id: I0dfe3b90a1507ad6138db10cc58e6e237a06a9d6
Move set_partition_seg_context_ to common file. Use consistent
context setup conditions for partition probability model update at
encoder and decoder.
Change-Id: I24b7ed3b1c48e3d2568191a46b70136b99b67b1a
Make framebuffer allocations according to the chroma subsamping
factors in use. A bit is placed in the raw part of the frame header for
each of the two subsampling factors. This will be moved in a future
commit to make them part of the TBD feature set bits, probably only set
on keyframes, etc.
Change-Id: I59ed38d3a3c0d4af3c7c277617de28d04a001853
Update and buffer left/above partition information context per 8x8
block. This allows to further enable recursive partition down to
4x4 block size, and hence deprecating I4X4_PRED and SPLITMV.
This commit also fixes a context buffer swap/restore issue in 32x32
partition type search. This gives 0.1% performance gain for derf/yt.
Will refactor the superblock partition type search into recursion
form.
Change-Id: Ib61975aca5f12b78d8018481d7fa1393d085689b
The number of reference buffers is extended to 8 and
a reference sign-bias added for the LAST_FRAME.
Whilst the number of reference buffers used by an
individual frame remains unchanged at 3, these may
now be selected from 8 possible buffers.
Change-Id: I2d247b9c1c2b3a339d6c9fac125e81ba373f75a7
Don't allow i4x4 except for sb8x8 recursion step. Read only 4 (not 16)
i4x4 submodes if we are i4x4.
Change-Id: Iaaaced1a134006b2c96eed66f014300eae41e0ed
Work-in-progress, not yet ready for review. TODO items:
- bitstream writing (encoder) and reading (decoder)
- decoder reconstruction
Change-Id: I5afb7284e7e0480847b47cd0097cb469433c9081
Changing the order of probabilities inside mb_segment_tree_probs in order
to use treed_read/treed_write function instead of custom code.
Change-Id: I843487d5057913b9358db73da270893eefecc6c8
Function set_mb_row() and set_mb_col() do similar work and are always
called together, this commit merged them into a single function for
clarity and easy maintainence. This was a TODO item.
Change-Id: I956bd9ed6afb8b2b0469b20fd8bc893b26f8a0f3
This commit enables selecting probability models for recursive block
partition information syntax, depending on its above/left partition
information, as well as the current block size. These conditional
probability models are reasonably stationary and consistent across
frames, hence the backward adaptive approach is used to maintain and
update the contextual models.
It achieves coding performance gains (on top of enabling rectangular
block sizes):
derf: 0.242%
yt: 0.391%
hd: 0.376%
stdhd: 0.645%
Change-Id: Ie513d9673337f0d27abd65fb566b711d0844ec2e
Also some further simplification following removal
of top node code.
There is an issue in regards to the shared file vp8cx.h
in regard to the roi_map as this interface assumes that
there are only 4 segments. I have left the value here as
4 for now meaning that the roi_map interface is broken
for VP9.
Note that this change would have been easier if I hadn't
had to search for hard wire instances of the number 4
and <= 3.
Change-Id: Ia8b6deea4be4dbd20deb1656e689dd43a5f190e8
Remove top node optimization.
The improvement this gives is not sufficient to justify
the extra complexity.
Change-Id: I2bb4a12a50ffd52cacfa4a3e8acbb2e522066905
This fixes an intermittent mismatch issue cause by moving
the lossless mode decoding bit to after the loop filter
setup information. We need to ensure that the lossless bit
is decoded prior to loop filter setup.
Change-Id: I3faa3fff8e1013b7405dac91268350e059ed121e
Adds an experiment that codes an end-of-orientation symbol
for every eligible zero encountered in scan order.
This cleans out various other sub-experiments that were part
of the origiinal patch, which will be later included if found
useful.
Results are slightly positive on all sets (0.1 - 0.2% range).
Change-Id: I57765c605fefc7fb9d1b57f1b356843602abefaf
Moving all the probability updates after frame context selection.
This makes it clean and simple to store all the probs in single
struct that can be sent to hardware codec.
Change-Id: I2ec3de81adbd468d8ef34a914caae80a18c3ef56
Enable recursive partition information coding from SB64X64 down to
MB16X16. The bit-stream syntax is now supporting rectangular block
sizes. It starts from SB64X64 and recursively describes the partition
type of the current block. If the partition type is PARTITION_NONE,
the block is coded as a single unit; if it is PARTITION_HORZ or
PARTITION_VERT, the block is segmented into two independently coded
rectangular units, with no further partition needed; otherwise, the
block is segmented into 4 square blocks. i.e., PARTITION_SPLIT case,
each can be potentially further partitioned.
Forward adaptive probability modeling is used for the partition
information coding, conditioned on the current block size.
Change-Id: I499365fb547839d555498e3bcc0387d8a3587d87
This flag was added to VP8 to allow a mode where MB-level skipping
was not allowed, saving a bit per mb. It was never used in practice,
and hasn't been tested in VP9, so remove it.
Change-Id: Id450ec6904c6d06c1919508e7efc52d05cde5631
This is work-in-progress, it implements multiple ARF
encoding behind an experimental flag.
It adds the ability to insert multiple ARF frames into a
single ARF group. This patch implements the reordering
of the coded frames, and implements a fixed-length coding
pattern. It applies a fixed quantizer strategy based on
where the frame is in the coding sequence.
Further work to modify the rate control strategy is
ongoing and will be submitted via a set of future patches.
In this first step, each ARF group is recursively
bisected and an ARF frame added at that position in the
sequence. The recursion continues until ARF frames are
within MIN_GF_INTERVAL frames.
The code sits behind the "multiple-arf" experimental
flag ("CONFIG_MULTIPLE_ARF"). The experimental flag
"oneshotq" ("CONFIG_ONESHOTQ") also needs to be enabled
for this patch to work correctly.
Change-Id: Ie473b05ebb43ac473c0cfb659b2b8042823085e2
This patch changes the default with the modecoefprob expt
to use mode-based forward updates with one-node pegged
modeling.
The maximum difference with fully trained tables is now
less that 0.1%.
Change-Id: I06b44322e10c6703f93f3c1d48d973b1136a0618
With these fixed, the codec produces identical results regardless of
what literal values are used for the enum members in BLOCK_SIZE_*.
Change-Id: I26db8e08019b58ba432af1f0950ebe6b0eb4ad8c
The patch adds the flexibility to use standard EOB based coding
on smaller block sizes and nzc based coding on larger blocksizes.
The tx-sizes that use nzc based coding and those that use EOB based
coding are controlled by a function get_nzc_used().
By default, this function uses nzc based coding for 16x16 and 32x32
transform blocks, which seem to bridge the performance gap
substantially.
All sets are now lower by 0.5% to 0.7%, as opposed to ~1.8% before.
Change-Id: I06abed3df57b52d241ea1f51b0d571c71e38fd0b
Pearson correlation for above or left is significantly higher than for
previous-in-scan-order (absolute values depend on position in scan, but
in general, we gain about 0.1-0.2 by using either above or left; using
both basically just makes this even better). For eob branch skipping,
we continue to use the previous token in scan order.
This helps about 0.9% on derf after re-training on a limited data set.
Full re-training and results on larger-resolution clips are pending.
Note that this commit breaks trellis, so we can probably get further
gains out of it by fixing trellis at some later point.
Change-Id: Iead68e296fc3a105cca746b5e3da9555d6010cfe
Adds a per-frame, strength adjustable, in loop deringing filter. Uses
the existing vp9_post_proc_down_and_across 5 tap thresholded blur
code, with a brute force search for the threshold.
Results almost strictly positive on the YT HD set, either having no
effect or helping PSNR in the range of 1-3% (overall average 0.8%).
Results more mixed for the CIF set, (-0.5 min, 1.4 max, 0.1 avg).
This has an almost strictly negative impact to SSIM, so examining a
different filter or a more balanced search heuristic is in order.
Other test set results pending.
Change-Id: I5ca6ee8fe292dfa3f2eab7f65332423fa1710b58
Replaces the default tables for single coefficient magnitudes with
those obtained from an appropriate distribution. The EOB node
is left unchanged. The model is represeted as a 256-size codebook
where the index corresponds to the probability of the Zero or the
One node. Two variations are implemented corresponding to whether
the Zero node or the One-node is used as the peg. The main advantage
is that the default prob tables will become considerably smaller and
manageable. Besides there is substantially less risk of over-fitting
for a training set.
Various distributions are tried and the one that gives the best
results is the family of Generalized Gaussian distributions with
shape parameter 0.75. The results are within about 0.2% of fully
trained tables for the Zero peg variant, and within 0.1% of the
One peg variant.
The forward updates are optionally (controlled by a macro)
model-based, i.e. restricted to only convey probabilities from the
codebook. Backward updates can also be optionally (controlled by
another macro) model-based, but is turned off by default. Currently
model-based forward updates work about the same as unconstrained
updates, but there is a drop in performance with backward-updates
being model based.
The model based approach also allows the probabilities for the key
frames to be adjusted from the defaults based on the base_qindex of
the frame. Currently the adjustment function is a placeholder that
adjusts the prob of EOB and Zero node from the nominal one at higher
quality (lower qindex) or lower quality (higher qindex) ends of the
range. The rest of the probabilities are then derived based on the
model from the adjusted prob of zero.
Change-Id: Iae050f3cbcc6d8b3f204e8dc395ae47b3b2192c9
Renaming Width to width, Height to height and Version to version in
several structs and function signatures.
Change-Id: I084c3f7e747cb2ce3345aff27a3dff9b13a87543
If the intended display size is different than the size the frame is
coded at, then send that size explicitly in the bitstream. Adds a new
bit to the frame header to indicate whether the extra size fields
are present.
Change-Id: I525c66f22d207efaf1e5f903c6a2a91b80245854
The previous implementation visited each node in the tree multiple times
because it used each symbol's encoding to revisit the branches taken and
increment its count. Instead, we can traverse the tree depth first and
calculate the probabilities and branch counts as we walk back up. The
complexity goes from somewhere between O(nlogn) and O(n^2) (depending on
how balanced the tree is) to O(n).
Only tested one clip (256kbps, CIF), saw 13% decoding perf improvement.
Note that this optimization should port trivially to VP8 as well. In VP8,
the decoder doesn't use this function, but it does routinely show up
on the profile for realtime encoding.
Change-Id: I4f2848e4f41dc9a7694f73f3e75034bce08d1b12
Adds probability updates for extra bits for the nzcs, code for
getting nzc stats, plus some minor cleanups and fixes.
Change-Id: If2814e7f04fb52f5025ad9f400f3e6c50a00b543
This patch revamps the entropy coding of coefficients to code first
a non-zero count per coded block and correspondingly remove the EOB
token from the token set.
STATUS:
Main encode/decode code achieving encode/decode sync - done.
Forward and backward probability updates to the nzcs - done.
Rd costing updates for nzcs - done.
Note: The dynamic progrmaming apporach used in trellis quantization
is not exactly compatible with nzcs. A suboptimal approach has been
used instead where branch costs are updated to account for changes
in the nzcs.
TODO:
Training the default probs/counts for nzcs
Change-Id: I951bc1e22f47885077a7453a09b0493daa77883d
Split macroblock and superblock tokenization and detokenization
functions and coefficient-related data structs so that the bitstream
layout and related code of superblock coefficients looks less like it's
a hack to fit macroblocks in superblocks.
In addition, unify chroma transform size selection from luma transform
size (i.e. always use the same size, as long as it fits the predictor);
in practice, this means 32x32 and 64x64 superblocks using the 16x16 luma
transform will now use the 16x16 (instead of the 8x8) chroma transform,
and 64x64 superblocks using the 32x32 luma transform will now use the
32x32 (instead of the 16x16) chroma transform.
Lastly, add a trellis optimize function for 32x32 transform blocks.
HD gains about 0.3%, STDHD about 0.15% and derf about 0.1%. There's
a few negative points here and there that I might want to analyze
a little closer.
Change-Id: Ibad7c3ddfe1acfc52771dfc27c03e9783e054430
Fixed a couple of variable/function definitions, as well as header
handling to support 16K sequence coding at high bit-rates.
The width and height are each specified by two bytes in the header.
Use an extra byte to explicitly indicate the scaling factors in
both directions, each ranging from 0 to 15.
Tested coding up to 16400x16400 dimension.
Change-Id: Ibc2225c6036620270f2c0cf5172d1760aaec10ec
This patch alters the balance of context between the
coefficient bands (reflecting the position of coefficients
within a transform blocks) and the energy of the previous
token (or tokens) within a block.
In this case the number of coefficient bands is reduced
but more previous token energy bands are supported.
Some initial rebalancing of the default tables has been
by running multiple derf clips at multiple data rates using
the ENTOPY_STATS macro. Further balancing needs to be
done using larger image formatsd especially in regard to
the bigger transform sizes which are not as well represented
in encodings of smaller image formats.
Change-Id: If9736e95c391e711b04aef6393d26f60f36e1f8a
The commit changes the coding mode to lossless whenever the lowest
quantizer is choosen.
As expected, test results showed no difference for cif and std-hd
set where Q0 is rarely used. For yt and yt-hd set, Q0 is used for
a number of clips, where this commit helped a lot in the high end.
Average over all clips in the sets:
yt: 2.391% 1.017% 1.066%
hd: 1.937% .764% .787%
Change-Id: I9fa9df8646fd70cb09ffe9e4202b86b67da16765
Since there is no Y2, these values are always zero. This changes the
bitstream results slightly, hence a separate commit.
Change-Id: I2f838f184341868f35113ec77ca89da53c4644e0
These allow sending partial bitstream packets over the network before
encoding a complete frame is completed, thus lowering end-to-end
latency. The tile-rows are not independent.
Change-Id: I99986595cbcbff9153e2a14f49b4aa7dee4768e2
1. Added a bit in frame header to to indicate if a frame is encoded
in lossless mode, so decoder does not make the decision based on Q0
2. Minor changes to make sure that lossy coding works same as when
the lossless experiment is not enabled.
3. Renamed function pointers for transforms to be consistent, using
prefix fwd_txm and inv_txm for forward and inverse respectively
To encode in lossless mode, using "--lossless=1 --min-q=0 --max-q=0"
with vpxenc.
Change-Id: Ifae53b26d2ffbe378d707e29d96817b8a5e6c068
This is after discussion with the hardware team. Update the unit test
to take these sizes into account. Split out some duplicate code into
a separate file so it can be shared.
Change-Id: I8311d11b0191d8bb37e8eb4ac962beb217e1bff5
* changes:
Initial support for resolution changes on P-frames
Avoid allocating memory when resizing frames
Adds a test for the VP8E_SET_SCALEMODE control
Allows inter-frames to change resolution. Currently these are
almost equivalent to keyframes, as only intra prediction modes
are allowed, but without the other context resets that occur on
keyframes.
Change-Id: Icd1a2a5af0d9462cc792588427b0a1f5b12e40d3
Tweak to default mode context to account for the fact
that when there are no non zero motion candidates
Nearest is now the preferred mode for coding a 0,0
vector.
Also resolve duplicate function name and typos.
Change-Id: I76802788d46c84e3d1c771be216a537ab7b12817
This patch adds column-based tiling. The idea is to make each tile
independently decodable (after reading the common frame header) and
also independendly encodable (minus within-frame cost adjustments in
the RD loop) to speed-up hardware & software en/decoders if they used
multi-threading. Column-based tiling has the added advantage (over
other tiling methods) that it minimizes realtime use-case latency,
since all threads can start encoding data as soon as the first SB-row
worth of data is available to the encoder.
There is some test code that does random tile ordering in the decoder,
to confirm that each tile is indeed independently decodable from other
tiles in the same frame. At tile edges, all contexts assume default
values (i.e. 0, 0 motion vector, no coefficients, DC intra4x4 mode),
and motion vector search and ordering do not cross tiles in the same
frame.
t log
Tile independence is not maintained between frames ATM, i.e. tile 0 of
frame 1 is free to use motion vectors that point into any tile of frame
0. We support 1 (i.e. no tiling), 2 or 4 column-tiles.
The loopfilter crosses tile boundaries. I discussed this briefly with Aki
and he says that's OK. An in-loop loopfilter would need to do some sync
between tile threads, but that shouldn't be a big issue.
Resuls: with tiling disabled, we go up slightly because of improved edge
use in the intra4x4 prediction. With 2 tiles, we lose about ~1% on derf,
~0.35% on HD and ~0.55% on STD/HD. With 4 tiles, we lose another ~1.5%
on derf ~0.77% on HD and ~0.85% on STD/HD. Most of this loss is
concentrated in the low-bitrate end of clips, and most of it is because
of the loss of edges at tile boundaries and the resulting loss of intra
predictors.
TODO:
- more tiles (perhaps allow row-based tiling also, and max. 8 tiles)?
- maybe optionally (for EC purposes), motion vectors themselves
should not cross tile edges, or we should emulate such borders as
if they were off-frame, to limit error propagation to within one
tile only. This doesn't have to be the default behaviour but could
be an optional bitstream flag.
Change-Id: I5951c3a0742a767b20bc9fb5af685d9892c2c96f
First step in simplifying the segment mode and
segment EOB flags into a simpler segment skip
flag that implies 0,0 mv and EOB at position 0.
Change-Id: Ib750cac31a7a02dc21082580498efd9f7d8d72a5
Adds a flag to disable features that would inhibit frame parallel
decoding. This includes backward adaptation and MV sorting based
on search in ref frame buffer.
Also includes some minor clean-ups.
Change-Id: I434846717a47b7bcb244b37ea670c5cdf776f14d
Adds an error-resilient mode where frames can be continued
to be decoded even when there are errors (due to network losses)
on a prior frame. Specifically, backward updates are turned off
and probabilities of various symbols are reset to defaults at
the beginning of each frame. Further, the last frame's mvs are
not used for the mv reference list, and the sorting of the
initial list based on search on previous frames is turned off
as well.
Also adds a test where an arbitrary set of frames are skipped
from decoding to simulate errors. The test verifies (1) that if
the error frames are droppable - i.e. frame buffer updates have
been turned off - there are no mismatch errors for the remaining
frames after the error frames; and (2) if the error-frames are non
droppable, there are not only no decoding errors but the mismatch
PSNR between the decoder's version of the post-error frames and the
encoder's version is at least 20 dB.
Change-Id: Ie6e2bcd436b1e8643270356d3a930e8989ff52a5
This commit restores the quality lost when the buffer-to-buffer copy
logic was removed. Note that this is specific to the current use of
golden frames and will need rework when RTC functionality is added.
Change-Id: I7324a75acd96eafd9e0f9b8633d782e390d5dc21
Previously there were two frame coding contexts tracked, one for normal
frames and one for alt-ref frames. Generalize this by signalling the
context to use in the bitstream, rather than tieing it to the alt ref
refresh bit. Also increase the number of contexts available to 4, which
may be useful for temporal scalability.
Change-Id: I7b66daaddd55c535c20cd16713541fab182b1662
Remove lst_fb_idx, gld_fb_idx, alt_fb_idx, refresh_last_frame,
refresh_golden_frame, refresh_alt_ref_frame from common. Gold/Alt are
encode side conventions. From the decoder's perspective, we want to be
dealing with numbered references.
Updates to active_ref 2 signal mode context switches, vestigial from
refresh_alt_ref_frame. This needs some clean up to make sense with
increased numbers of reference frames, as well as reimplementing the
swapping of alt/golden which was previously done using the
buffer-to-buffer copy mechanism removed in an earlier commit.
Change-Id: I7334445158b7666f9295d2a2dd22aa03f4485f58
This is the first in a series of commits to add additional reference
frames to the codec. Each frame will be able to update any of the
available references, but copying between references is not
supported.
Change-Id: I5945b5ce6cc3582c495102b4e7eed4f08c44d5a1
This experiment gives little gains and adds relatively much code
complexity (and it hinders other experiments), so let's get rid of
it.
Change-Id: Id25e79a137a1b8a01138aa27a1fa0ba4a2df274a
This patch removes the old pred-filter experiment and replaces it
with one that is implemented using the switchable filter framework.
If the pred-filter experiment is enabled, three interopolation
filters are tested during mode selection; the standard 8-tap
interpolation filter, a sharp 8-tap filter and a (new) 8-tap
smoothing filter.
The 6-tap filter code has been preserved for now and if the
enable-6tap experiment is enabled (in addition to the pred-filter
experiment) the original 6-tap filter replaces the new 8-tap smooth
filter in the switchable mode.
The new experiment applies the prediction filter in cases of a
fractional-pel motion vector. Future patches will apply the filter
where the mv is pel-aligned and also to intra predicted blocks.
Change-Id: I08e8cba978f2bbf3019f8413f376b8e2cd85eba4
This patch changes the token packing to call the bool encoder API rather
than inlining it into the token packing function, and similarly removes
a special get_signed case from the detokenizer. This allows easier
experimentation with changing the bool coder as a whole.
Change-Id: I52c3625bbe4960b68cfb873b0e39ade0c82f9e91
Add a function clip_pixel() to clip a pixel value to the [0,255] range
of allowed values, and use this where-ever appropriate (e.g. prediction,
reconstruction). Likewise, consistently use the recently added function
clip_prob(), which calculates a binary probability in the [1,255] range.
If possible, try to use get_prob() or its sister get_binary_prob() to
calculate binary probabilities, for consistency.
Since in some places, this means that binary probability calculations
are changed (we use {255,256}*count0/(total) in a range of places,
and all of these are now changed to use 256*count0+(total>>1)/total),
this changes the encoding result, so this patch warrants some extensive
testing.
Change-Id: Ibeeff8d886496839b8e0c0ace9ccc552351f7628
Some further changes and refactoring of mv
reference code and selection of center point for
searches. Mainly relates to not passing so many
different local copies of things around.
Some place holder comments.
Change-Id: I309f10ffe9a9cde7663e7eae19eb594371c8d055
