diff options
| -rw-r--r-- | lib/bunzip.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/lib/bunzip.c b/lib/bunzip.c index 7804b7fa..139848e7 100644 --- a/lib/bunzip.c +++ b/lib/bunzip.c @@ -211,8 +211,10 @@ int read_bunzip_data(bunzip_data *bd) /* Calculate permute[], base[], and limit[] tables from length[]. * * permute[] is the lookup table for converting huffman coded symbols - * into decoded symbols. base[] is the amount to subtract from the - * value of a huffman symbol of a given length when using permute[]. + * into decoded symbols. It contains symbol values sorted by length. + * + * base[] is the amount to subtract from the value of a huffman symbol + * of a given length when using permute[]. * * limit[] indicates the largest numerical value a symbol with a given * number of bits can have. It lets us know when to stop reading. @@ -231,20 +233,20 @@ int read_bunzip_data(bunzip_data *bd) base = hufGroup->base-1; limit = hufGroup->limit-1; - // Calculate permute[] + // Calculate permute[], and zero temp[] and limit[]. pp = 0; for (i = minLen; i <= maxLen; i++) + temp[i] = limit[i] = 0; for (t = 0; t < symCount; t++) if (length[t] == i) hufGroup->permute[pp++] = t; - // Count cumulative symbols coded for at each bit length - for (i = minLen; i <= maxLen; i++) temp[i] = limit[i] = 0; + // Count symbols coded for at each bit length for (i = 0; i < symCount; i++) temp[length[i]]++; /* Calculate limit[] (the largest symbol-coding value at each bit * length, which is (previous limit<<1)+symbols at this level), and * base[] (number of symbols to ignore at each bit length, which is - * limit-cumulative count of symbols coded for already). */ + * limit minus the cumulative count of symbols coded for already). */ pp = t = 0; for (i = minLen; i < maxLen; i++) { pp += temp[i]; |