Valery Valentin authored Mar 05, 2019 and David Flynn committed Apr 16, 2019

This LoD generation (subsampling) method uses the Morton-based ordering
of points that is used to determine prediction neighbours.  Each LoD
level comprises 3/4 of the points of the previous.

Toshiyasu Sugio authored Mar 01, 2019 and David Flynn committed Apr 16, 2019

This commit introduces zero run length coding for attribute residual
value along with an eq1 flag which indicates if residual value is equal
to 1 based on the current residual coding specification. In zero run
length coding, the number of zeros prior to each residual value is
counted as zerorun, and then zerorun is encoded instead of encoding
sequence of 0s

This commit permits signalling a per-slice delta QP for luma and
chroma attribute components.  The delta is relative to the base
value derived from the APS.

NB: while syntax support and derivation processes are provided,
this commit does not contain any method to control the delta
QP value at the encoder.

Noritaka Iguchi authored Mar 27, 2019 and David Flynn committed Apr 16, 2019

This commit introduces control of the quantisation step size using
the familiar HEVC | AVC quantisation parameter.

This is part of a series attempting to remove unhelpful typedefs.

The old typedefs (PCCVector3D, PCCPoint3D, PCCColor3B) are retained for
compatibility, but marked as deprecated.

This is part of a series attempting to remove unhelpful typedefs.

This is part of a series that implements a single method of Cartesian to
Morton code conversion.

Vladyslav Zakharchenko authored Dec 14, 2018 and David Flynn committed Feb 06, 2019

This uses a binary-tree to generate the levels-of-details for the
lifting/predicting transforms as an alternative to Euclidean distance
thresholding methods.

Jungsun Kim authored Jan 30, 2019 and David Flynn committed Feb 05, 2019

This simplified attribute prediction scheme avoids computing the
LoD structure in order to reduce the computational complexity of
both the encoder and the decoder.  It is activated by setting
levelOfDetailCount=0.

NB: this is only configured for lossless/near-lossless predictive
attribute coding of cat3 sequences.

Danillo Bracco Graziosi authored Dec 12, 2018 and David Flynn committed Feb 05, 2019

This replaces the previous floating point transform implementation with
a fixed-point alternative with essentially identical compression
performance.

Khaled Mammou authored Sep 22, 2018 and David Flynn committed Nov 01, 2018

Replace the k-d tree based nearest neighbour search with an approximate
search based upon the points in Morton order.

Toshiyasu Sugio authored Sep 20, 2018 and David Flynn committed Nov 01, 2018

This commit provides an ability to vary the number of direct neighbours
used in the predicting transform.  Mode 0 corresponds to the existing
averaging, and mode n selects the n-th nearest neighbour for direct
prediction.

The provided code has been reworked to:
 - rewrite unary coding to be a little more obvious
 - tidy the mode decision path
 - add configuration for max_num_direct_predictors (renamed from
   MaxNumPredCand)
 - now counts the number of single predictors, rather than prediction
   modes.

This commit adds an arithmetic codec interface class that allows a
compile time choice of arithmetic codec implementation.  Context types
are renamed to support compile time selection, and existing support
functions that were added to the third-party arithmetic codec are
moved to the wrapper.

Khaled Mammou authored Sep 18, 2018 and David Flynn committed Nov 01, 2018

This commit replaces the m-ary coding of transform coefficient values
with a binary coding using the dual-lut coder.

Reworked to include a bug fix where the maximum attribute symbol value
used by the dual lut coder is 64 rather than 255

This commit removes unnecessary include directives.

This commit moves various constants from PCCTMC3Common.h to a new
constants.h.  Hard coded values of constants have been replaced with
their symbolic name.

Khaled Mammou authored Aug 22, 2018 and David Flynn committed Aug 29, 2018

This commit removes the ability to vary quant_step_size on a per-LoD
basis.  This greatly simplifies the codec configuration, especially
when used in conjunction with dist2 derivation.

cfg update:
 - rename quantizationSteps* -> quantizationStep*
 - update quantizationStep* to single values:
   - lossless-geom lossy-attrs:        8, 16, 32, 64, 128, 256 [8bit]
   - lossless-geom nearlossless-attrs: no change
   - lossless-geom lossless-attrs:     no change
   - lossy-geom    lossy-attrs:        8                       [8bit]

 => 16-bit cat3 sequences are have 8-bit qs values multipled by 255

Khaled Mammou authored Aug 23, 2018 and David Flynn committed Aug 29, 2018

This commit removes PCCBuildLevelOfDetail2()

Khaled Mammou authored Aug 22, 2018 and David Flynn committed Aug 29, 2018

This commit replaces the hard coded threshold values with APS signalling.
The default configuration maintains the hard-coded threshold values based
on bitdepth.

This is an editorial change to improve naming clarity: attr_count
represents the number of elements (dimensionality) in an attribute
set rather than the total number of attributes.

This commit allows the attribute codec to be parametrised by attribute
bitdepth.  The attribute bitdepth is signalled in the attribute's sequence
parameter set description.  The specified bitdepth affects cliping in the
attribute prediction and reconstruction process.

This commit rewrites the codec high-level syntax:

 - the bitstream is divided into "bricks" (akin to an AVC/HEVC
   slice/tile).

 - sequence, geometry and attribute parameter sets describe the coding
   parameters in use generally and for a specific brick.

 - marshalling the bitstream payloads to a file format is achieved using
   a type-length-value encoding scheme.

Additionally, the triSoup bitstream scale and translation values have
been unified with (replaced by) the octree counterparts.  For
compatibility, existing command line parameters continue to function
as before.

NB: this commit does not incorporate flexibility in the decoding order.
The decoder requires the bitstream to be presented in a fixed order.

The IntegerLift name is misleading in light of a separate coding method
that uses lifting predict and update operators.  This commit renames
the method to specify it is a prediction-only scheme.

Khaled Mammou authored Jun 30, 2018 and David Flynn committed Aug 20, 2018

This commit implements a lifting scheme optimized for lossy attribute
compression, consisting of predict/update operators, and an adaptive
quantization strategy.

Khaled Mammou authored Jun 30, 2018 and David Flynn committed Aug 20, 2018

Adaptively pick the number of neighbours considered during the
prediction based on analysis of the reconstructed attribute values of
the neighbours.

From m42642, this is performed by computing the maximum difference
between any two reconstructed attribute values of a points neighbours.
If the variability is higher than a threshold, then apply a
rate-distortion optimization procedure to choose between using either
a single neighbour or all neighbours. The index of the best prediction
strategy is arithmetically encoded.

This commit:
 - implements the m42642 method
 - moves buildPredictors into transform-specific attribute encoding/decoding
 - adds quantizationStepsChroma
 - renames quantizationSteps -> quantizationStepsLuma

df: fixed incorrect application of quantizationStepsLuma|Chroma
df: updated cat3 cfg to specify quantizationStepsChroma
df: fixed header encoding if quantizationStepsChroma missing

Little is gained from the return type checks, it mostly serves to
clutter the code.

Rather than coding all syntax elements for both transform types
irrespective of the in-use type, this commit codes only those that
are necessary for a given transform type.

Philip A. Chou authored Apr 03, 2018 and David Flynn committed Jun 05, 2018

This commit introduces the rahtLeafDecimationDepth parameter to allow
chroma sub-sampling by decimating the coefficients in the bottom n
levels of the tree.

The default value of 3 provides chroma sub-sampling by a factor of 2
in each dimension.

Philip A. Chou authored Mar 25, 2018 and David Flynn committed Jun 05, 2018

This commit ports the Region Adaptive Hierarchical Transform for
attribute coding with colour and reflectance variants.

Khaled Mammou authored Mar 25, 2018 and David Flynn committed Jun 05, 2018

This commit reorganises the attribute coders to allow integration
of the RAHT variant.

In order to support multiple different attribute compression schemes,
this commit moves the existing attribute compression code into a
self-contained class.