This is to address issue #157.

Author: aous72

src/core/codestream/ojph_codeblock_fun.cpp

@@ -205,6 +205,7 @@ namespace ojph {
 
       #ifndef OJPH_DISABLE_AVX2
         if (get_cpu_ext_level() >= X86_CPU_EXT_LEVEL_AVX2) {
+          decode_cb32 = ojph_decode_codeblock_avx2;
           find_max_val32 = avx2_find_max_val32;
           if (reversible) {
             tx_to_cb32 = avx2_rev_tx_to_cb32;
@@ -215,7 +216,8 @@ namespace ojph {
             tx_from_cb32 = avx2_irv_tx_from_cb32;
           }
           encode_cb32 = ojph_encode_codeblock_avx2;
-          decode_cb32 = ojph_decode_codeblock_avx2;
+          bool result = initialize_block_encoder_tables_avx2();
+          assert(result);
 
           find_max_val64 = avx2_find_max_val64;
           if (reversible) {
@@ -231,8 +233,11 @@ namespace ojph {
       #endif // !OJPH_DISABLE_AVX2
 
       #if (defined(OJPH_ARCH_X86_64) && !defined(OJPH_DISABLE_AVX512))
-        if (get_cpu_ext_level() >= X86_CPU_EXT_LEVEL_AVX512)
+        if (get_cpu_ext_level() >= X86_CPU_EXT_LEVEL_AVX512) {
           encode_cb32 = ojph_encode_codeblock_avx512;
+          bool result = initialize_block_encoder_tables_avx512();
+          assert(result);
+        }
       #endif // !OJPH_DISABLE_AVX512
 
     #elif defined(OJPH_ARCH_ARM)

src/core/coding/ojph_block_encoder.h

@@ -78,6 +78,9 @@ namespace ojph {
                                    ui32 stride, ui32* lengths,
                                    ojph::mem_elastic_allocator *elastic,
                                    ojph::coded_lists *& coded);
+
+    bool initialize_block_encoder_tables_avx2();
+    bool initialize_block_encoder_tables_avx512();
   }
 }
 

src/core/coding/ojph_block_encoder_avx2.cpp

@@ -218,22 +218,19 @@ namespace ojph {
     }
 
     /////////////////////////////////////////////////////////////////////////
-    bool initialize_tables_avx2() {
-      if (get_cpu_ext_level() >= X86_CPU_EXT_LEVEL_AVX2) {
+    static bool tables_initialized = false;
+
+    /////////////////////////////////////////////////////////////////////////
+    bool initialize_block_encoder_tables_avx2() {
+      if (!tables_initialized) {
         memset(vlc_tbl0, 0, 2048 * sizeof(ui32));
         memset(vlc_tbl1, 0, 2048 * sizeof(ui32));
-
-        bool result;
-        result = vlc_init_tables();
-        result = result && uvlc_init_tables();
-        return result;
+        tables_initialized = vlc_init_tables();
+        tables_initialized = tables_initialized && uvlc_init_tables();
       }
-      return false;
+      return tables_initialized;
     }
 
-    /////////////////////////////////////////////////////////////////////////
-    static bool tables_initialized = initialize_tables_avx2();
-
     /////////////////////////////////////////////////////////////////////////
     //
     /////////////////////////////////////////////////////////////////////////

src/core/coding/ojph_block_encoder_avx512.cpp

@@ -218,23 +218,19 @@ namespace ojph {
     }
 
     /////////////////////////////////////////////////////////////////////////
-    bool initialize_tables() {
-      if (get_cpu_ext_level() >= X86_CPU_EXT_LEVEL_AVX512) 
-      {
+    static bool tables_initialized = false;
+
+    /////////////////////////////////////////////////////////////////////////
+    bool initialize_block_encoder_tables_avx512() {
+      if (!tables_initialized) {
         memset(vlc_tbl0, 0, 2048 * sizeof(ui32));
         memset(vlc_tbl1, 0, 2048 * sizeof(ui32));
-
-        bool result;
-        result = vlc_init_tables();
-        result = result && uvlc_init_tables();
-        return result;
+        tables_initialized = vlc_init_tables();
+        tables_initialized = tables_initialized && uvlc_init_tables();
       }
-      return false;
+      return tables_initialized;
     }
 
-    /////////////////////////////////////////////////////////////////////////
-    static bool tables_initialized = initialize_tables();
-
     /////////////////////////////////////////////////////////////////////////
     //
     /////////////////////////////////////////////////////////////////////////