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IDProjectCategoryView StatusLast Update
0000256JVT JM H.264/AVC reference softwareencoder and decoderpublic2011-05-02 12:55
ReporterAjay Basarur Assigned ToYuwen He  
PriorityurgentSeveritytweakReproducibilityalways
Status resolvedResolutionfixed 
Product VersionJM 17.2 
Fixed in VersionJM 18.0 
Summary0000256: DPB Size Usage for Encoder & Decoder
DescriptionAccording to Annex H , the DPB size is calculated as below
The DPB size depends upon the number of views.
In section H.10.2 point (f), standard mentioned an equation for DPB size [page 651]
Max_DPBSize = Min( mvcScaleFactor * MaxDpbMbs / ( PicWidthInMbs * FrameHeightInMbs ),
   Max( 1, Ceil( log2( NumViews ) ) ) * 16 );
                        [where Ceil( x ) the smallest integer greater than or equal to x]

         So, the whole equation should not exceed the second operand value i.e. [Max(1, Ceil(log2(NumViews))) * 16].
         The dpbsize based on equation is…
        
NumViews Max DPB Size
1 Or 2 16
3 Or 4 32
5,6,7 Or 8 48
--------------------------------------------------------------------------------
Problem: The Encoder & Decoder uses DPB size of 32 for 2 Views. According to standard it should be restricted to 16 only.
Steps To ReproduceFiles - mbuffer.c [Decoder]
function: GetMaxDecFrameBuffering ()

Files - mbuffer.c [Encoder]
line no: 232
TagsNo tags attached.

Activities

Karsten Suehring

2011-05-02 12:55

administrator   ~0000452

Fixed in development tree

Issue History

Date Modified Username Field Change
2011-04-25 09:23 Ajay Basarur New Issue
2011-05-02 12:55 Karsten Suehring Note Added: 0000452
2011-05-02 12:55 Karsten Suehring Status new => resolved
2011-05-02 12:55 Karsten Suehring Fixed in Version => JM 18.0
2011-05-02 12:55 Karsten Suehring Resolution open => fixed
2011-05-02 12:55 Karsten Suehring Assigned To => Yuwen He