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path: root/core/multimedia/opieplayer/libmad/bit.c
authorharlekin <harlekin>2002-04-19 16:08:55 (UTC)
committer harlekin <harlekin>2002-04-19 16:08:55 (UTC)
commit7ea4abeb652e6787e57a938e1ca028d25fd249ce (patch) (side-by-side diff)
treeee08f2d9d6aaa8adb1c5f07f4124da8a61eb8cd5 /core/multimedia/opieplayer/libmad/bit.c
parentcaa7ced77b9014526607f9f65c58aabe7e0ba631 (diff)
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new libmad version, less cpu usage
Diffstat (limited to 'core/multimedia/opieplayer/libmad/bit.c') (more/less context) (ignore whitespace changes)
-rw-r--r--core/multimedia/opieplayer/libmad/bit.c39
1 files changed, 28 insertions, 11 deletions
diff --git a/core/multimedia/opieplayer/libmad/bit.c b/core/multimedia/opieplayer/libmad/bit.c
index 2466c5f..4a4661b 100644
--- a/core/multimedia/opieplayer/libmad/bit.c
+++ b/core/multimedia/opieplayer/libmad/bit.c
@@ -1,5 +1,5 @@
/*
- * mad - MPEG audio decoder
+ * libmad - MPEG audio decoder library
* Copyright (C) 2000-2001 Robert Leslie
*
* This program is free software; you can redistribute it and/or modify
@@ -197,22 +197,39 @@ void mad_bit_write(struct mad_bitptr *bitptr, unsigned int len,
unsigned short mad_bit_crc(struct mad_bitptr bitptr, unsigned int len,
unsigned short init)
{
- register unsigned int crc, data;
+ register unsigned int crc;
-# if CHAR_BIT == 8
- for (crc = init; len >= 8; len -= 8) {
- crc = (crc << 8) ^
- crc_table[((crc >> 8) ^ mad_bit_read(&bitptr, 8)) & 0xff];
+ for (crc = init; len >= 32; len -= 32) {
+ register unsigned long data;
+
+ data = mad_bit_read(&bitptr, 32);
+
+ crc = (crc << 8) ^ crc_table[((crc >> 8) ^ (data >> 24)) & 0xff];
+ crc = (crc << 8) ^ crc_table[((crc >> 8) ^ (data >> 16)) & 0xff];
+ crc = (crc << 8) ^ crc_table[((crc >> 8) ^ (data >> 8)) & 0xff];
+ crc = (crc << 8) ^ crc_table[((crc >> 8) ^ (data >> 0)) & 0xff];
+ }
+
+ switch (len / 8) {
+ case 3: crc = (crc << 8) ^
+ crc_table[((crc >> 8) ^ mad_bit_read(&bitptr, 8)) & 0xff];
+ case 2: crc = (crc << 8) ^
+ crc_table[((crc >> 8) ^ mad_bit_read(&bitptr, 8)) & 0xff];
+ case 1: crc = (crc << 8) ^
+ crc_table[((crc >> 8) ^ mad_bit_read(&bitptr, 8)) & 0xff];
+
+ len %= 8;
+
+ case 0: break;
}
-# else
- crc = init;
-# endif
while (len--) {
- data = mad_bit_read(&bitptr, 1) ^ (crc >> 15);
+ register unsigned int msb;
+
+ msb = mad_bit_read(&bitptr, 1) ^ (crc >> 15);
crc <<= 1;
- if (data & 1)
+ if (msb & 1)
crc ^= CRC_POLY;
}