X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Feac3dec.c;h=0b10b41848a1256a9880f83b1b3e8b28143f46ee;hb=ede725104b57c6bf0fa6b20f18d1035ea091e1cc;hp=836cb8ef0524b748121d4562826bf2eef242ecd1;hpb=1ffbafa02b3cbc00e24a92cba8cd3a66ba02ec50;p=ffmpeg

diff --git a/libavcodec/eac3dec.c b/libavcodec/eac3dec.c
index 836cb8ef052..0b10b41848a 100644
--- a/libavcodec/eac3dec.c
+++ b/libavcodec/eac3dec.c
@@ -131,7 +131,7 @@ void ff_eac3_decode_transform_coeffs_aht_ch(AC3DecodeContext *s, int ch)
             /* Vector Quantization */
             int v = get_bits(gbc, bits);
             for (blk = 0; blk < 6; blk++) {
-                s->pre_mantissa[ch][bin][blk] = ff_eac3_vq_hebap[hebap][v][blk] << 8;
+                s->pre_mantissa[ch][bin][blk] = ff_eac3_mantissa_vq[hebap][v][blk] << 8;
             }
         } else {
             /* Gain Adaptive Quantization */
@@ -420,21 +420,21 @@ int ff_eac3_parse_header(AC3DecodeContext *s)
 
     /* determine which channels use AHT */
     if (parse_aht_info) {
-        /* AHT is only available when there are 6 blocks in the frame.
-           The coupling channel can only use AHT when coupling is in use for
-           all blocks.
-           reference: Section E3.3.2 Bit Stream Helper Variables */
+        /* For AHT to be used, all non-zero blocks must reuse exponents from
+           the first block.  Furthermore, for AHT to be used in the coupling
+           channel, all blocks must use coupling and use the same coupling
+           strategy. */
         s->channel_uses_aht[CPL_CH]=0;
         for (ch = (num_cpl_blocks != 6); ch <= s->channels; ch++) {
-            int nchregs = 0;
-            for (blk = 0; blk < 6; blk++) {
-                if (ch)
-                    nchregs += (s->exp_strategy[blk][ch] != EXP_REUSE);
-                else
-                    nchregs += s->cpl_strategy_exists[blk] ||
-                               (s->exp_strategy[blk][CPL_CH] != EXP_REUSE);
+            int use_aht = 1;
+            for (blk = 1; blk < 6; blk++) {
+                if ((s->exp_strategy[blk][ch] != EXP_REUSE) ||
+                        (!ch && s->cpl_strategy_exists[blk])) {
+                    use_aht = 0;
+                    break;
+                }
             }
-            s->channel_uses_aht[ch] = (nchregs == 1) && get_bits1(gbc);
+            s->channel_uses_aht[ch] = use_aht && get_bits1(gbc);
         }
     } else {
         memset(s->channel_uses_aht, 0, sizeof(s->channel_uses_aht));