diff --git a/libavcodec/ac3dec.c b/libavcodec/ac3dec.c
index 49b170c235..dbe7f0b57c 100644
--- a/libavcodec/ac3dec.c
+++ b/libavcodec/ac3dec.c
@@ -55,9 +55,7 @@ static uint8_t ungroup_3_in_7_bits_tab[128][3];
 /** tables for ungrouping mantissas */
 static int b1_mantissas[32][3];
 static int b2_mantissas[128][3];
-static int b3_mantissas[8];
 static int b4_mantissas[128][2];
-static int b5_mantissas[16];
 
 /**
  * Quantization table: levels for symmetric. bits for asymmetric.
@@ -155,16 +153,6 @@ static av_cold void ac3_tables_init(void)
         b4_mantissas[i][0] = symmetric_dequant(i / 11, 11);
         b4_mantissas[i][1] = symmetric_dequant(i % 11, 11);
     }
-    /* generate ungrouped mantissa tables
-       reference: Tables 7.21 and 7.23 */
-    for (i = 0; i < 7; i++) {
-        /* bap=3 mantissas */
-        b3_mantissas[i] = symmetric_dequant(i, 7);
-    }
-    for (i = 0; i < 15; i++) {
-        /* bap=5 mantissas */
-        b5_mantissas[i] = symmetric_dequant(i, 15);
-    }
 
 #if (!USE_FIXED)
     /* generate dynamic range table
@@ -595,7 +583,7 @@ static void ac3_decode_transform_coeffs_ch(AC3DecodeContext *s, int ch_index, ma
             }
             break;
         case 3:
-            mantissa = b3_mantissas[get_bits(gbc, 3)];
+            mantissa = ff_ac3_bap3_mantissas[get_bits(gbc, 3)];
             break;
         case 4:
             if (m->b4) {
@@ -609,7 +597,7 @@ static void ac3_decode_transform_coeffs_ch(AC3DecodeContext *s, int ch_index, ma
             }
             break;
         case 5:
-            mantissa = b5_mantissas[get_bits(gbc, 4)];
+            mantissa = ff_ac3_bap5_mantissas[get_bits(gbc, 4)];
             break;
         default: /* 6 to 15 */
             /* Shift mantissa and sign-extend it. */
diff --git a/libavcodec/ac3dec_data.c b/libavcodec/ac3dec_data.c
index a3794ab223..527b3353f2 100644
--- a/libavcodec/ac3dec_data.c
+++ b/libavcodec/ac3dec_data.c
@@ -21,7 +21,7 @@
 
 /**
  * @file
- * Tables taken directly from the AC-3 spec.
+ * Tables taken directly from the AC-3 spec or derived from it.
  */
 
 #include "ac3dec_data.h"
@@ -42,6 +42,43 @@ const uint8_t ff_ac3_ungroup_3_in_5_bits_tab[32][3] = {
     { 3, 0, 1 }, { 3, 0, 2 }, { 3, 1, 0 }, { 3, 1, 1 }
 };
 
+/**
+ * Ungrouped mantissa tables; the extra entry is padding to avoid range checks
+ */
+#define SYMMETRIC_DEQUANT(code, levels) (((code - (levels >> 1)) * (1 << 24)) / levels)
+/**
+ * Table 7.21
+ */
+const int ff_ac3_bap3_mantissas[7 + 1] = {
+    SYMMETRIC_DEQUANT(0, 7),
+    SYMMETRIC_DEQUANT(1, 7),
+    SYMMETRIC_DEQUANT(2, 7),
+    SYMMETRIC_DEQUANT(3, 7),
+    SYMMETRIC_DEQUANT(4, 7),
+    SYMMETRIC_DEQUANT(5, 7),
+    SYMMETRIC_DEQUANT(6, 7),
+};
+/**
+ * Table 7.23
+ */
+const int ff_ac3_bap5_mantissas[15 + 1] = {
+    SYMMETRIC_DEQUANT(0,  15),
+    SYMMETRIC_DEQUANT(1,  15),
+    SYMMETRIC_DEQUANT(2,  15),
+    SYMMETRIC_DEQUANT(3,  15),
+    SYMMETRIC_DEQUANT(4,  15),
+    SYMMETRIC_DEQUANT(5,  15),
+    SYMMETRIC_DEQUANT(6,  15),
+    SYMMETRIC_DEQUANT(7,  15),
+    SYMMETRIC_DEQUANT(8,  15),
+    SYMMETRIC_DEQUANT(9,  15),
+    SYMMETRIC_DEQUANT(10, 15),
+    SYMMETRIC_DEQUANT(11, 15),
+    SYMMETRIC_DEQUANT(12, 15),
+    SYMMETRIC_DEQUANT(13, 15),
+    SYMMETRIC_DEQUANT(14, 15),
+};
+
 const uint8_t ff_eac3_hebap_tab[64] = {
     0, 1, 2, 3, 4, 5, 6, 7, 8, 8,
     8, 8, 9, 9, 9, 10, 10, 10, 10, 11,
diff --git a/libavcodec/ac3dec_data.h b/libavcodec/ac3dec_data.h
index 975b52ef2c..4f3a23f6c7 100644
--- a/libavcodec/ac3dec_data.h
+++ b/libavcodec/ac3dec_data.h
@@ -24,9 +24,18 @@
 
 #include <stdint.h>
 
+#include "libavutil/attributes_internal.h"
+
+FF_VISIBILITY_PUSH_HIDDEN
+
 extern const uint8_t ff_ac3_ungroup_3_in_5_bits_tab[32][3];
 
+extern const int     ff_ac3_bap3_mantissas[ 7 + 1];
+extern const int     ff_ac3_bap5_mantissas[15 + 1];
+
 extern const uint8_t ff_eac3_hebap_tab[64];
 extern const uint8_t ff_eac3_default_spx_band_struct[17];
 
+FF_VISIBILITY_POP_HIDDEN
+
 #endif /* AVCODEC_AC3DEC_DATA_H */