Xiang Zhang authored Aug 19, 2019 and David Flynn committed Nov 21, 2019

This introduces a quantization scheme into the octree coding process,
enables adaptive geometry quantization for different regions of the
point cloud.  This in-loop scheme is independent of the any quantisation
performed in non-normative pre-processing at the input to the encoder.

At a particular depth of the octree, the remaining (uncoded) position
bits of each point are quantised according to a per-node (or rather,
per-subtree) QP.  The QP itself is signalled as an offset to a base QP.

The following configuration parameters are added:
  positionQuantisationEnabled
  positionBaseQp
  positionQuantisationOctreeDepth

Satoru KUMA authored May 31, 2019 and David Flynn committed Nov 21, 2019

This provides a means to achieve spatial scalability for a G-PCC
bitstream.  For bitstreams encoded with aps_scalable_enabled_flag set,
the decoder may partially decode the geometry octree
(minGeomNodeSizeLog2) and the corresponding point attributes.  The
functionality is achieved by constraining the LoD generation process to
align with partial geometry decoding.

A 64 bit integer can represent a three dimensional 21 bit position with
one spare bit.  In order te allow the computation of abs(a-b), a signed
representation should be used, making use of the full 64 bits.

This proposal reduces the number of neighbour configurations used
in occupancy contextualisation from {10, 10, 10, 10, 10, 10, 7, 5}
to {9, 9, 9, 9, 5, 5, 3, 2} by replacing the 64-to-10, 10-to-7,
and 10-to-5 mapping tables with 64-to-9, 9-to-5, and 9-to-3 tables.

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

Replaces the existing map update tables (generated from (L*p+s)/(L+1),
memory L=10) with an adaptive memory (L=max(5, 1/p, 1/(1-p)) clipped
to 200) represented as delta transitions and quantised to 16 entries.

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.

chi wang authored Oct 09, 2018 and David Flynn committed Nov 01, 2018

When restricted neighbour contextualisation is used, this modification
introduces an alternative neighbour reduction table.

NB: the integrated table has been updated to remove the need to add
additional remapping tables.  This is a non-normative change.

Bitwise geometry occupancy coding uses a mapping table to select entropy
contexts.  This commit employs a dynamic mapping which is updated after
each coding operation, replacing the previous static mapping tables.

NB: the proposed version used a context with a halving period
(max_count) of 64 symbols.  However, this conflicts with another
adoption (512 symbols), and a wholesale replacement of the arithmetic
codec and context model.  To resolve the conflict, the existing halving
period (128) is used.

This commit provides an encapsulated interface to the fast update option
of the o3dgc context models with a statistic halving period of 128
symbols (max_count).

Philip A. Chou authored Jul 19, 2018 and David Flynn committed Nov 01, 2018

This commit integrates a c++ trisoup codec, replacing the previous matlab
implementation.

The provided code has been reworked to avoid duplicating code, dead code,
and operate with the current HLS.

This commit replaces some repetitive code with a loop.

The geometry coder is quite large, especially with trisoup and has no
benefit to being a header only implementation.  This commit moves the
geometry octree coder out of the header files and into
geometry_octree_{en,de}coder.cpp.

This avoids an issue with g++-4.8.



git-svn-id: http://wg11.sc29.org/svn/repos/MPEG-I/Part5-PointCloudCompression/TM/TMC3/trunk@1338 94298a81-5874-47c9-aab8-bfb24faeed7f

This commit changes the application's reporting of elapsed time to
measure user time rather than wall time in order to reduce sources
of noise in evaluating runtime.

For output is now of the form:

  ```
  Processing time (wall): 123.456 s
  Processing time (user): 123.456 s
  ```



git-svn-id: http://wg11.sc29.org/svn/repos/MPEG-I/Part5-PointCloudCompression/TM/TMC3/trunk@1329 94298a81-5874-47c9-aab8-bfb24faeed7f