[dep-quant] Fix read out of bounds and left shift of negative

ultravideo · Jul 1, 2024 · d008a00 · d008a00
1 parent 634cf72
commit d008a00
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/src/dep_quant.c b/src/dep_quant.c
@@ -573,8 +573,8 @@ static INLINE void update_common_context(
   uint8_t*       sbbFlags = cc->m_allSbbCtx[cc->m_curr_sbb_ctx_offset].sbbFlags;
   uint8_t*       levels = cc->m_allSbbCtx[cc->m_curr_sbb_ctx_offset].levels;
   size_t         setCpSize = cc->m_nbInfo[scan_pos - 1].maxDist * sizeof(uint8_t);
-  int8_t         prev_sbb_state = ctxs->m_allStates.m_refSbbCtxId[prev_state];
-  if (prev_state != -1 && prev_sbb_state >= 0) {
+  if (prev_state != -1) {
+    const int8_t prev_sbb_state = ctxs->m_allStates.m_refSbbCtxId[prev_state];
     for (int i = 0; i < numSbb; ++i) {
       sbbFlags[i * 4 + curr_state_without_offset] = cc->m_allSbbCtx[cc->m_prev_sbb_ctx_offset].sbbFlags[i * 4 + prev_sbb_state];
     }
@@ -1130,7 +1130,7 @@ void uvg_dep_quant_dequant(
       {
         invQScale <<= -shift;
       }
-      int  qIdx = (level << 1) + (level > 0 ? -(state >> 1) : (state >> 1));
+      int  qIdx = (level * 2) + (level > 0 ? -(state >> 1) : (state >> 1));
       int64_t  nomTCoeff = ((int64_t)qIdx * (int64_t)invQScale + add) >> ((shift < 0) ? 0 : shift);
       coeff[rasterPos] = (coeff_t)CLIP(minTCoeff, maxTCoeff, nomTCoeff);
     }