Opened 12 months ago

Last modified 12 months ago

#126 new defect

bug for calculating target bits in rate control in case of TemporalSubsampleRatio not equals to one

Reported by: liye0713 Owned by:
Priority: minor Milestone:
Component: VTM Version: VTM-3.0
Keywords: Cc: ksuehring, XiangLi, fbossen, jvet@…

Description

In case of rate control is enabled, the sequence target bits is calculated from the given target rate.During the conversion from target rate to target bits, the frame rate should be considered. In VTM, the frame rate is constrained to be an integer number. So in case of temporal subsample ratio, the frame rate is divided and then rounded from the original value:

(int)((double)m_iFrameRate / m_temporalSubsampleRatio + 0.5)

Right now, the target rate is set as the actually coded rate when the sequence is coded in QP 22, 27,32,37 with rate control disabled. When using the actually coded bits to calculate the actual rate, the frame rate is regarded as float number not int. In case of this inconsistency, the target bits set for rate control will be largely different from the actually coded bits.

Attachments (1)

source.patch (2.5 KB) - added by liye0713 11 months ago.
patch of the 'source' directory after setting the frame rate as double format in case of rate control

Download all attachments as: .zip

Change history (2)

comment:1 Changed 12 months ago by ksuehring

  • Version set to VTM-3.0

Changed 11 months ago by liye0713

patch of the 'source' directory after setting the frame rate as double format in case of rate control

Note: See TracTickets for help on using tickets.