+/**
+ * Map audio coding mode (acmod) to channel layout mask.
+ */
+const uint16_t ff_ac3_channel_layout_tab[8] = {
+ CH_LAYOUT_STEREO,
+ CH_LAYOUT_MONO,
+ CH_LAYOUT_STEREO,
+ CH_LAYOUT_SURROUND,
+ CH_LAYOUT_2_1,
+ CH_LAYOUT_4POINT0,
+ CH_LAYOUT_2_2,
+ CH_LAYOUT_5POINT0
+};
+
+#define COMMON_CHANNEL_MAP \
+ { { 0, 1, }, { 0, 1, 2, } },\
+ { { 0, }, { 0, 1, } },\
+ { { 0, 1, }, { 0, 1, 2, } },\
+ { { 0, 2, 1, }, { 0, 2, 1, 3, } },\
+ { { 0, 1, 2, }, { 0, 1, 3, 2, } },\
+ { { 0, 2, 1, 3, }, { 0, 2, 1, 4, 3, } },
+
+/**
+ * Table to remap channels from SMPTE order to AC-3 order.
+ * [channel_mode][lfe][ch]
+ */
+const uint8_t ff_ac3_enc_channel_map[8][2][6] = {
+ COMMON_CHANNEL_MAP
+ { { 0, 1, 2, 3, }, { 0, 1, 3, 4, 2, } },
+ { { 0, 2, 1, 3, 4, }, { 0, 2, 1, 4, 5, 3 } },
+};
+
+/**
+ * Table to remap channels from from AC-3 order to SMPTE order.
+ * [channel_mode][lfe][ch]
+ */
+const uint8_t ff_ac3_dec_channel_map[8][2][6] = {
+ COMMON_CHANNEL_MAP
+ { { 0, 1, 2, 3, }, { 0, 1, 4, 2, 3, } },
+ { { 0, 2, 1, 3, 4, }, { 0, 2, 1, 5, 3, 4 } },
+};
+