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IDProjectCategoryView StatusLast Update
0000165JVT JM H.264/AVC reference softwareencoderpublic2011-05-20 10:43
ReporterRobert Cohen Assigned ToKarsten Suehring  
PrioritynormalSeveritytextReproducibilityN/A
Status resolvedResolutionfixed 
Product VersionJM 15.1 
Target VersionJM 18.1Fixed in VersionJM 18.1 
Summary0000165: SubPelBlockMotionSearch comment field: pel or sub-pel?
DescriptionIn JM 15.1, m_fullsearch.c, line 256, for SubPelBlockMotionSearch():

  MotionVector *mv, // <--> in: search center / out: motion vector - in pel units

 Are the input and output mv's in this case pel units, or should it say sub-pel units? This would apply to all the other sub-pel motion search functions as well.
Tagsmotion estimation

Activities

Karsten Suehring

2011-05-19 15:36

administrator   ~0000482

I don't think we use full-pel motion vectors in the ME modules. But this needs to be double-checked.

Alexis Michael Tourapis

2011-05-19 18:59

developer   ~0000483

Motion estimation uses full precision motion vectors. However, for all motion estimation modules except EPZS (and obviously any subpel refinement steps), only integer positions are checked. EPZS allows a special mode that enables the search to operate on even subpel positions. This special mode of EPZS can be enabled using the EPZSSubPelGrid.

The comment description is legacy from how the software used to operate.

Karsten Suehring

2011-05-20 10:43

administrator   ~0000484

After Alexis confirmed that motion vectors are always 1/4 pel I ran a search/replace pattern on the software. Fixed in JM-18.0-dev.

Issue History

Date Modified Username Field Change
2009-02-27 23:00 Robert Cohen New Issue
2011-05-19 15:36 Karsten Suehring Note Added: 0000482
2011-05-19 15:36 Karsten Suehring Assigned To => Alexis Michael Tourapis
2011-05-19 15:36 Karsten Suehring Status new => acknowledged
2011-05-19 15:37 Karsten Suehring Tag Attached: motion estimation
2011-05-19 15:39 Karsten Suehring Target Version => JM 18.1
2011-05-19 18:59 Alexis Michael Tourapis Note Added: 0000483
2011-05-20 10:43 Karsten Suehring Note Added: 0000484
2011-05-20 10:43 Karsten Suehring Status acknowledged => resolved
2011-05-20 10:43 Karsten Suehring Fixed in Version => JM 18.1
2011-05-20 10:43 Karsten Suehring Resolution open => fixed
2011-05-20 10:43 Karsten Suehring Assigned To Alexis Michael Tourapis => Karsten Suehring