diff --git a/decoder/ihevcd_api.c b/decoder/ihevcd_api.c
index 5289a12..a0d82dd 100644
--- a/decoder/ihevcd_api.c
+++ b/decoder/ihevcd_api.c
@@ -1215,7 +1215,7 @@
 
     /* Request memory for static bitstream buffer which holds bitstream after emulation prevention */
     size = MIN_BITSBUF_SIZE;
-    pv_buf = pf_aligned_alloc(pv_mem_ctxt, 128, size);
+    pv_buf = pf_aligned_alloc(pv_mem_ctxt, 128, size + 16); //Alloc extra for parse optimization
     RETURN_IF((NULL == pv_buf), IV_FAIL);
     ps_codec->pu1_bitsbuf_static = pv_buf;
     ps_codec->u4_bitsbuf_size_static = size;
@@ -1912,7 +1912,7 @@
     size = wd * ht;
     if(size > MIN_BITSBUF_SIZE)
     {
-        pv_buf = ps_codec->pf_aligned_alloc(pv_mem_ctxt, 128, size);
+        pv_buf = ps_codec->pf_aligned_alloc(pv_mem_ctxt, 128, size + 16); //Alloc extra for parse optimization
         RETURN_IF((NULL == pv_buf), IV_FAIL);
         ps_codec->pu1_bitsbuf_dynamic = pv_buf;
         ps_codec->u4_bitsbuf_size_dynamic = size;
diff --git a/decoder/ihevcd_parse_headers.c b/decoder/ihevcd_parse_headers.c
index afa6de3..4714f3a 100644
--- a/decoder/ihevcd_parse_headers.c
+++ b/decoder/ihevcd_parse_headers.c
@@ -1439,12 +1439,16 @@
 
     /* Check if sps_max_dec_pic_buffering or sps_max_num_reorder_pics
        has changed */
-    if(0 != ps_codec->i4_first_pic_done)
+    if(0 != ps_codec->u4_allocate_dynamic_done)
     {
         sps_t *ps_sps_old = ps_codec->s_parse.ps_sps;
         if(ps_sps_old->ai1_sps_max_dec_pic_buffering[ps_sps_old->i1_sps_max_sub_layers - 1] !=
                     ps_sps->ai1_sps_max_dec_pic_buffering[ps_sps->i1_sps_max_sub_layers - 1])
         {
+            if(0 == ps_codec->i4_first_pic_done)
+            {
+                return IHEVCD_INVALID_PARAMETER;
+            }
             ps_codec->i4_reset_flag = 1;
             return (IHEVCD_ERROR_T)IVD_RES_CHANGED;
         }
@@ -1452,6 +1456,10 @@
         if(ps_sps_old->ai1_sps_max_num_reorder_pics[ps_sps_old->i1_sps_max_sub_layers - 1] !=
                     ps_sps->ai1_sps_max_num_reorder_pics[ps_sps->i1_sps_max_sub_layers - 1])
         {
+            if(0 == ps_codec->i4_first_pic_done)
+            {
+                return IHEVCD_INVALID_PARAMETER;
+            }
             ps_codec->i4_reset_flag = 1;
             return (IHEVCD_ERROR_T)IVD_RES_CHANGED;
         }
@@ -1625,10 +1633,14 @@
         ps_sps->i2_pic_ht_in_min_cb = numerator  /
                         (1 << ps_sps->i1_log2_min_coding_block_size);
     }
-    if((0 != ps_codec->i4_first_pic_done) &&
+    if((0 != ps_codec->u4_allocate_dynamic_done) &&
                     ((ps_codec->i4_wd != ps_sps->i2_pic_width_in_luma_samples) ||
                     (ps_codec->i4_ht != ps_sps->i2_pic_height_in_luma_samples)))
     {
+        if(0 == ps_codec->i4_first_pic_done)
+        {
+            return IHEVCD_INVALID_PARAMETER;
+        }
         ps_codec->i4_reset_flag = 1;
         return (IHEVCD_ERROR_T)IVD_RES_CHANGED;
     }
@@ -2325,9 +2337,18 @@
         if(ps_vui_hdr->u1_sub_pic_cpb_params_present_flag
                         && ps_vui_hdr->u1_sub_pic_cpb_params_in_pic_timing_sei_flag)
         {
+            UWORD32 num_units_minus1;
+            UWORD32 array_size;
+
             UEV_PARSE("num_decoding_units_minus1", value, ps_bitstrm);
             ps_pic_timing->u4_num_decoding_units_minus1 = value;
 
+            num_units_minus1 = ps_pic_timing->u4_num_decoding_units_minus1;
+            array_size = (sizeof(ps_pic_timing->au4_num_nalus_in_du_minus1)
+                       / sizeof(ps_pic_timing->au4_num_nalus_in_du_minus1[0]));
+            num_units_minus1 = CLIP3(num_units_minus1, 0,(array_size - 1));
+            ps_pic_timing->u4_num_decoding_units_minus1 = num_units_minus1;
+
             BITS_PARSE("du_common_cpb_removal_delay_flag", value, ps_bitstrm, 1);
             ps_pic_timing->u1_du_common_cpb_removal_delay_flag = value;