Fix: reference POC initialization and add a check for I-slice in reference index setting for AH0069
Fix reference POC initialization and add a check for I-slice in reference index setting, related to #70.
Reference POCs m_aiRefPOCList
are initialized with 0, which is a valid POC values, so not a good initialization in general.
Next, in Slice::setRefRefIdxList()
the condition is checked whether refRefPOC is equal to the refPOC, so the for the second picture in the decoding order the refPOC is the first I-picture, where refRefPOC, which is a reference picture of the I-picture, is not available, but since it is initialized to 0, the condition check refRefPOC == getRefPOC(RefPicList(iCurrDir), iCurrRefIdx)
will pass.
When segments are merged the first I-picture POC is not 0 any more, so that condition won't be true, hence the mismatch.
Solution in the fix is to initialize refPOCs with -1 and add I-slice check.