Mismatch with spec on MergeTriangleFlag derivation

[forayr]

In spec:

If all the following conditions are true, MergeTriangleFlag[ x0 ][ y0 ] is set equal to 1:
    • sps_triangle_enabled_flag is equal to 1.
    • slice_type is equal to B.
    • general_merge_flag[ x0 ][ y0 ] is equal to 1.
    • MaxNumTriangleMergeCand is greater than or equal to 2.
    • cbWidth * cbHeight is greater than or equal to 64.
    • regular_merge_flag[ x0 ][ y0 ] is equal to 0.
    • mmvd_merge_flag[ x0 ][ y0 ] is equal to 0.
    • merge_subblock_flag[ x0 ][ y0 ] is equal to 0.
    • ciip_flag[ x0 ][ y0 ] is equal to 0.
Otherwise, MergeTriangleFlag[ x0 ][ y0 ] is set equal to 0.

In vtm (CABACReader.cpp):

pu.cu->triangle = pu.cu->cs->slice->getSPS()->getUseTriangle() &&
 pu.cu->cs->slice->isInterB() &&
 !pu.cu->affine &&
 !pu.mmvdMergeFlag &&
 !pu.cu->mmvdSkip;

Especially the condition on MaxNumTriangleMergeCand is missing when decoding.

[forayr]

MR: ​https://vcgit.hhi.fraunhofer.de/jvet/VVCSoftware_VTM/merge_requests/642

[ksuehring]

MR was merged