Opened 10 years ago

Closed 10 years ago

#175 closed defect (fixed)

Clipping in removeHighFreq considered slightly harmful

Reported by: nsprljan Owned by:
Priority: minor Milestone:
Component: HM Version:
Keywords: Cc: fbossen, ksuehring, davidf, jct-vc@…

Description

Function TComYuv::removeHighFreq is called only during ME for bipredictive case, where clipping of the unidirectional part is done as in the following:

pDst[x ] = xClip( (pDst[x ]<<1) - pSrc[x ] );

This makes the prediction operation to be (O is the predicted signal, R1 and R2 are references):

(clip(2*O - R1) - R2 )/ 2

When clipping is omitted, results for 24 frames are as follows (based on HM-3.0-dev):

                  Random access              Random access LoCo
         Y BD-rateU BD-rateV BD-rateY BD-rateU BD-rateV BD-rate
Class A  0.0      0.0      0.2      0.0     -0.1     -0.2 
Class B  0.1     -0.1     -0.1      0.0     -0.1      0.1 
Class C -0.1     -0.3      0.1      0.0     -0.5     -0.3 
Class D  0.0     -0.4     -0.3     -0.2     -0.2     -0.6 
All      0.0     -0.2     -0.1     -0.1     -0.2     -0.2 
 
                                                      
         Low delay                           Low delay LoCo
         Y BD-rateU BD-rateV BD-rateY BD-rateU BD-rateV BD-rate
Class B -0.1     -0.3     -0.1      0.0      0.1      0.2 
Class C  0.0      0.2     -0.1      0.0      0.2      0.2 
Class D  0.0      0.0      0.4     -0.2     -0.2     -0.6 
Class E -0.1      0.1     -0.2      0.0     -0.1      0.2 
All     -0.1      0.0      0.0      0.0      0.0      0.0 

Change History (4)

comment:1 Changed 10 years ago by davidf

  • Component set to HM

Updating component after adding WD (Text) tickets

comment:2 Changed 10 years ago by davidf

  • Cc fbossen ksuehring davidf added

comment:3 Changed 10 years ago by davidf

  • Cc jct-vc@… added

comment:4 Changed 10 years ago by fbossen

  • Resolution set to fixed
  • Status changed from new to closed
Note: See TracTickets for help on using tickets.

This list contains all users that will be notified about changes made to this ticket.

These roles will be notified: Reporter, Owner, Subscriber, Participant

  • David Flynn(Subscriber, Participant)
  • Frank Bossen(Subscriber, Participant)
  • jct-vc@…(Subscriber)
  • karl.sharman@…(Always)
  • Karsten Suehring(Subscriber, Always)
  • Nikola Sprljan(Reporter)