Fix slot management across sequence #186
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During a resolution change (e.g., 352x288 → 176x144), the parser was incorrectly managing DPB slot indices, leading to out-of-bounds access and driver crashes. Root cause #1: Wrong sequence update detection ---------------------------------------------- The code used nMaxWidth/nMaxHeight to detect if this was a sequence update vs. first sequence: bool sequenceUpdate = ((m_nvsi.nMaxWidth != 0) && (m_nvsi.nMaxHeight != 0)); Problem: nMaxWidth/nMaxHeight can legitimately be 0 for many H.264 bitstreams (they're optional VUI fields). This caused the second sequence to be incorrectly treated as 'first sequence'. Fix: Use nCodedWidth/nCodedHeight instead, which are always set. Root cause #2: Stale DPB slot indices carried across resize ----------------------------------------------------------- When sequenceUpdate was incorrectly false, the DPB was reinitialized but the old m_pictureToDpbSlotMap entries persisted with slot indices that could exceed the new (possibly smaller) m_dpbMaxSize. Later, when the parser tried to FreeSlot(slot >= new m_dpbMaxSize), it triggered: - Debug: assert '(uint8_t)slot < m_dpbMaxSize' failed - Release: undefined behavior → driver crash / device lost Fix: On coded-extent reconfigure, fully reset DPB state: - m_dpbSlotsMask = 0 - m_fieldPicFlagMask = 0 - m_pictureToDpbSlotMap[*] = -1 This ensures the new sequence starts with a clean DPB, which is correct since a resolution change implies an IDR with no references to the previous sequence. Note: This fix works together with the timeline semaphore fix in VulkanVideoFrameBuffer.cpp (commit d437b6a9) to fully resolve the resize crash. Signed-off-by: Tony Zlatinski <[email protected]>
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