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CODECS: Replaced Integer log2 in QDM2 with Common::Math implementation.

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This commit is contained in:
D G Turner 2011-07-19 02:07:15 +01:00
parent 45f1f1275c
commit 765813f750
1 changed files with 3 additions and 17 deletions
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20
audio/decoders/qdm2.cpp
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@ -34,6 +34,7 @@
#include "common/array.h"
#include "common/debug.h"
#include "common/math.h"
#include "common/stream.h"
#include "common/textconsole.h"
@ -289,21 +290,6 @@ private:
typedef signed long long int int64_t;
#endif
// Integer log2 function. This is much faster than invoking
// double precision C99 log2 math functions or equivalent, since
// this is only used to determine maximum number of bits needed
// i.e. only non-fractional part is needed. Also, the double
// version is incorrect for exact cases due to floating point
// rounding errors.
static inline int scummvm_log2(int n) {
int ret = -1;
while(n != 0) {
n /= 2;
ret++;
}
return ret;
}
#define QDM2_LIST_ADD(list, size, packet) \
do { \
if (size > 0) \
@ -1836,11 +1822,11 @@ QDM2Stream::QDM2Stream(Common::SeekableReadStream *extraData, DisposeAfterUse::F
warning("QDM2Stream::QDM2Stream() u4 field not 0");
}
_fftOrder = scummvm_log2(_frameSize) + 1;
_fftOrder = log2(_frameSize) + 1;
_fftFrameSize = 2 * _frameSize; // complex has two floats
// something like max decodable tones
_groupOrder = scummvm_log2(_blockSize) + 1;
_groupOrder = log2(_blockSize) + 1;
_sFrameSize = _blockSize / 16; // 16 iterations per super block
_subSampling = _fftOrder - 7;