when trying to create a file with video that has negative composition time offsets:

mp4Box -dash 1000 -out out.mpd -dash-profile onDemand --cmaf=cmfc vvc_uhd2_hdr-ClosedGOP-7680x4320_50fps-HLG10-30s-12Mbps.mp4  

the segment index box signals SAP_type=1 and the mpd signal subsegmentStartsWithSAP="1" 

This should for this specific file be 2, as the first decoded sample is not the first one displayed.

also it may be easier to always signal 2 for dash as sap type 1 is a subset of sap type 1. 

My suggestion is to put the correct SapType in the mpd and segment index or always put 2

mp4Box incorrect sap type in segment index box and mpd
This is a GitHub Issue
repo:gpac
owner:gpac
Title : mp4Box incorrect sap type in segment index box and mpd
Issue date:

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when trying to create a file with video that has negative composition time offsets:

mp4Box -dash 1000 -out out.mpd -dash-profile onDemand --cmaf=cmfc vvc_uhd2_hdr-ClosedGOP-7680x4320_50fps-HLG10-30s-12Mbps.mp4  

the segment index box signals SAP_type=1 and the mpd signal subsegmentStartsWithSAP="1" 

This should for this specific file be 2, as the first decoded sample is not the first one displayed.

also it may be easier to always signal 2 for dash as sap type 1 is a subset of sap type 1. 

My suggestion is to put the correct SapType in the mpd and segment index or always put 2

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