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16th Meeting: Geneva, October 2019 2019-10-03 09:06
AHG17: DPB size analysis of VTM6.0 using RA configuration in current CTC
Authors: X. Ma Huawei Hyeong-Gyun Yang Huawei
Abstract
This contribution provides an analysis of the decoded picture buffer (DPB) size of VTM6.0 using RA configuration in current CTC. It is found that the DPB size can achieve 7 in VTM, which is different from the value of high level syntax sps_max_dec_pic_buffering_minus1+1. It is suggested to modify the GOP structure to constrain the DPB size to be consistent with the syntax value.
Meeting Notes
JVET-P0133 AHG17: DPB size analysis of VTM6.0 using RA configuration in current CTC [X. Ma, H. Yang (Huawei)]

Discussed in plenary Sunday 6 October 1745 (GJS & JRO)

Other contributions on this topic JVET-O0667, JCTVC-AJ0030, JCTVC-AK0030.

This contribution provides an analysis of the decoded picture buffer (DPB) size of VTM6.0 using RA configuration in current CTC. It is found that the DPB size can achieve 7 in VTM, which is different from the value of high level syntax sps_max_dec_pic_buffering_minus1+1. It is suggested to modify the GOP structure to constrain the DPB size to be consistent with the syntax value.

The content of this contribution basically is the same as JVET-O0667, only the test result is updated using VTM6.0.

It was commented that the software does things a bit differently and does not provide output timing analysis. Only a few people had tried to check the validity of the problem, but it did appear that the current configuration is a problem for HEVC.

With the alternative proposed structure, the overall impact was 0.70% in RA (more impact at lower resolutions).

It was noted that Q15-C-11 had a proposal of up to 50 reference pictures.

It was commented that GOP size of 32 was subjectively even better.

It was suggested that, considering that memory is not as difficult to support as it once was, to go ahead and specify maxDpbPicBuf equal to 8 at this time. See the notes above for JVET-P0894.

References:
JVET-N1010 JVET-O0667
ARCHIVE v3 :
encoder_randomaccess_main10_proposed.cfg encoder_randomaccess_vtm_proposed.cfg JVET-P0133_HM16.20Fix_VS_HM19.20Org.XLSM JVET-P0133_r2.docx JVET-P0133_VTM6.0Fix_VS_HM16.20Fix_r1.XLSM JVET-P0133_VTM6.0Fix_VS_VTM6.0Org_r1.XLSM JVET-P0133_VTM6.0Org_VS_HM16.20Org_r1.XLSM
Decisions
It was suggested that, considering that memory is not as difficult to support as it once was, to go ahead and specify maxDpbPicBuf equal to 8 at this time. See the notes above for JVET-P0894.
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