View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000081 | JVT JM H.264/AVC reference software | decoder | public | 2007-10-17 13:11 | 2007-10-18 15:23 |
| Reporter | Priya | Assigned To | |||
| Priority | normal | Severity | minor | Reproducibility | N/A |
| Status | closed | Resolution | no change required | ||
| Product Version | JM 12.4 | ||||
| Summary | 0000081: Reordering reference picture | ||||
| Description | Hi, I am going through the reordering process for reference pictures in h.264 decoder. Can anyone explain me the need of code given below with reference to file mbuffer.c for "Reordering process for short-term reference pictures" for( cIdx = *refIdxLX; cIdx <= num_ref_idx_lX_active_minus1+1; cIdx++ ) if (RefPicListX[ cIdx ]) if( (RefPicListX[ cIdx ]->is_long_term ) || (RefPicListX[ cIdx ]->pic_num != picNumLX )) { RefPicListX[ nIdx++ ] = RefPicListX[ cIdx ]; | ||||
| Tags | No tags attached. | ||||
|
|
The code is an implementation of the pseudo-code in equation 8-38. If a reference picture has been inserted into a specific index of the reference picture list, occurrences of the same picture at higher reference picture indexes are removed from the list. |
|
|
As per my understanding ,this code does checks for the reoccurence of same picture at higher indexes but it doesn't delete them.List is unchanged after reordering as per the pseudo code given below for( cIdx = num_ref_idx_lX_active_minus1 + 1; cIdx > refIdxLX; cIdx-- ) RefPicListX[ cIdx ] = RefPicListX[ cIdx – 1] RefPicListX[ refIdxLX++ ] = short-term reference picture with PicNum equal to picNumLX. As per the above code picture to reorder is placed at reference index specified by refIdxLX and other pictures are shifted. Infact I can't understand the need to implement this pseudo code because as standard mentions that "A reference picture may appear at more than one index in the modified reference picture lists RefPicList0 or RefPicList1." Can you please elaborate on this. |
|
|
Note that cIdx differs from nIdx in that loop. The intention for this process was to reorder (i.e. move a picture from one location in the list to another) unless you explicitly specify it to appear on multiple locations within the list. The process is specified in Eq. 8.35. So you have to implement it to conform to the spec. |
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2007-10-17 13:11 | Priya | New Issue | |
| 2007-10-18 11:19 | Karsten Suehring | Status | new => closed |
| 2007-10-18 11:19 | Karsten Suehring | Note Added: 0000120 | |
| 2007-10-18 11:19 | Karsten Suehring | Resolution | open => no change required |
| 2007-10-18 14:57 | Priya | Status | closed => feedback |
| 2007-10-18 14:57 | Priya | Resolution | no change required => reopened |
| 2007-10-18 14:57 | Priya | Note Added: 0000122 | |
| 2007-10-18 15:23 | Karsten Suehring | Note Added: 0000123 | |
| 2007-10-18 15:23 | Karsten Suehring | Status | feedback => closed |
| 2007-10-18 15:23 | Karsten Suehring | Resolution | reopened => no change required |
