aacdec: fix undefined shifts
authorMans Rullgard <mans@mansr.com>
Sat, 8 Oct 2011 12:41:23 +0000 (13:41 +0100)
committerMans Rullgard <mans@mansr.com>
Sat, 8 Oct 2011 19:03:55 +0000 (20:03 +0100)
Since nnz can be zero, this is needed to avoid a shift by 32.

Signed-off-by: Mans Rullgard <mans@mansr.com>
libavcodec/aacdec.c

index ef5daed..8e7e74e 100644 (file)
@@ -1129,7 +1129,7 @@ static int decode_spectrum_and_dequant(AACContext *ac, float coef[1024],
                             GET_VLC(code, re, gb, vlc_tab, 8, 2);
                             cb_idx = cb_vector_idx[code];
                             nnz = cb_idx >> 8 & 15;
                             GET_VLC(code, re, gb, vlc_tab, 8, 2);
                             cb_idx = cb_vector_idx[code];
                             nnz = cb_idx >> 8 & 15;
-                            bits = SHOW_UBITS(re, gb, nnz) << (32-nnz);
+                            bits = nnz ? GET_CACHE(re, gb) : 0;
                             LAST_SKIP_BITS(re, gb, nnz);
                             cf = VMUL4S(cf, vq, cb_idx, bits, sf + idx);
                         } while (len -= 4);
                             LAST_SKIP_BITS(re, gb, nnz);
                             cf = VMUL4S(cf, vq, cb_idx, bits, sf + idx);
                         } while (len -= 4);
@@ -1169,7 +1169,7 @@ static int decode_spectrum_and_dequant(AACContext *ac, float coef[1024],
                             GET_VLC(code, re, gb, vlc_tab, 8, 2);
                             cb_idx = cb_vector_idx[code];
                             nnz = cb_idx >> 8 & 15;
                             GET_VLC(code, re, gb, vlc_tab, 8, 2);
                             cb_idx = cb_vector_idx[code];
                             nnz = cb_idx >> 8 & 15;
-                            sign = SHOW_UBITS(re, gb, nnz) << (cb_idx >> 12);
+                            sign = nnz ? SHOW_UBITS(re, gb, nnz) << (cb_idx >> 12) : 0;
                             LAST_SKIP_BITS(re, gb, nnz);
                             cf = VMUL2S(cf, vq, cb_idx, sign, sf + idx);
                         } while (len -= 2);
                             LAST_SKIP_BITS(re, gb, nnz);
                             cf = VMUL2S(cf, vq, cb_idx, sign, sf + idx);
                         } while (len -= 2);