View Issue Details
| ID | Project | Category | View Status | Date Submitted | Last Update |
|---|---|---|---|---|---|
| 0000102 | JVT JM H.264/AVC reference software | encoder | public | 2008-02-28 19:51 | 2008-07-24 15:06 |
| Reporter | Luca | Assigned To | Alexis Michael Tourapis | ||
| Priority | normal | Severity | minor | Reproducibility | always |
| Status | resolved | Resolution | fixed | ||
| Product Version | JM 13.1 | ||||
| Fixed in Version | JM-14.1 | ||||
| Summary | 0000102: Quantization Parameter per Slice | ||||
| Description | Dear Experts, I found a strange behaviour of the encoder when assigning a specific QP to a slice (with RDO turned off). For example, when writing in *slice.c - init_slice* a condition like if (img->current_slice_nr == 2) currSlice->qp = 42; else currSlice->qp = img->qp; it results on an appropriate assignment of the slice header field "slice_qp_delta" for the slice number 2. But then while encoding the MBs, in the function *macroblock.c - start_macroblock*, the QP of the current macroblock seems to be assigned depending on the img->qp, like if (prev_mb < 0) //first macroblock (of slice) { (*currMB)->delta_qp = 0; (*currMB)->qp = img->qp; } and so on. Therefore, when decoding, the decoder modifies the QP of the MB according to the slice_qp_delta. But at the encoder file, the reference pictures were created considering only the global QP of the sequence. If the information I gave you are correct, than I just propose to modify the assignment of currMB->qp to img->currentSlice->qp. Best Regards, Luca | ||||
| Tags | No tags attached. | ||||
| Date Modified | Username | Field | Change |
|---|---|---|---|
| 2008-02-28 19:51 | Luca | New Issue | |
| 2008-05-06 16:47 | Karsten Suehring | Note Added: 0000177 | |
| 2008-05-06 16:47 | Karsten Suehring | Status | new => confirmed |
| 2008-07-24 15:06 | Alexis Michael Tourapis | Status | confirmed => resolved |
| 2008-07-24 15:06 | Alexis Michael Tourapis | Fixed in Version | => JM-14.1 |
| 2008-07-24 15:06 | Alexis Michael Tourapis | Resolution | open => fixed |
| 2008-07-24 15:06 | Alexis Michael Tourapis | Assigned To | => Alexis Michael Tourapis |
