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Diffstat (limited to 'scumm/imuse_digi/dimuse_codecs.cpp')
-rw-r--r--scumm/imuse_digi/dimuse_codecs.cpp162
1 files changed, 67 insertions, 95 deletions
diff --git a/scumm/imuse_digi/dimuse_codecs.cpp b/scumm/imuse_digi/dimuse_codecs.cpp
index efab0a6382..e4b4be6c7c 100644
--- a/scumm/imuse_digi/dimuse_codecs.cpp
+++ b/scumm/imuse_digi/dimuse_codecs.cpp
@@ -15,7 +15,6 @@
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
- * $Header$
*/
#include "stdafx.h"
@@ -194,7 +193,7 @@ static int32 compDecode(byte *src, byte *dst) {
int data, size, bit, bitsleft = 16, mask = READ_LE_UINT16(srcptr);
srcptr += 2;
- while (1) {
+ for (;;) {
NextBit;
if (bit) {
*dstptr++ = *srcptr++;
@@ -269,22 +268,23 @@ int32 decompressCodec(int32 codec, byte *comp_input, byte *comp_output, int32 in
memset(t_table, 0, output_size);
src = comp_output;
- length = (output_size * 8) / 12;
+ length = (output_size << 3) / 12;
k = 0;
if (length > 0) {
c = -12;
s = 0;
j = 0;
do {
- ptr = src + length + k / 2;
+ ptr = src + length + (k >> 1);
+ t_tmp2 = src[j];
if (k & 1) {
- r = c / 8;
- t_table[r + 2] = ((src[j] & 0x0f) << 4) | (ptr[1] >> 4);
- t_table[r + 1] = (src[j] & 0xf0) | (t_table[r + 1]);
+ r = c >> 3;
+ t_table[r + 2] = ((t_tmp2 & 0x0f) << 4) | (ptr[1] >> 4);
+ t_table[r + 1] = (t_tmp2 & 0xf0) | (t_table[r + 1]);
} else {
- r = s / 8;
- t_table[r + 0] = ((src[j] & 0x0f) << 4) | (ptr[0] & 0x0f);
- t_table[r + 1] = src[j] >> 4;
+ r = s >> 3;
+ t_table[r + 0] = ((t_tmp2 & 0x0f) << 4) | (ptr[0] & 0x0f);
+ t_table[r + 1] = t_tmp2 >> 4;
}
s += 12;
c += 12;
@@ -292,7 +292,7 @@ int32 decompressCodec(int32 codec, byte *comp_input, byte *comp_output, int32 in
j++;
} while (k < length);
}
- offset1 = ((length - 1) * 3) / 2;
+ offset1 = ((length - 1) * 3) >> 1;
t_table[offset1 + 1] = (t_table[offset1 + 1]) | (src[length - 1] & 0xf0);
memcpy(src, t_table, output_size);
free(t_table);
@@ -310,24 +310,25 @@ int32 decompressCodec(int32 codec, byte *comp_input, byte *comp_output, int32 in
memset(t_table, 0, output_size);
src = comp_output;
- length = (output_size * 8) / 12;
+ length = (output_size << 3) / 12;
k = 1;
c = 0;
s = 12;
- t_table[0] = src[length] / 16;
+ t_table[0] = src[length] >> 4;
t = length + k;
j = 1;
if (t > k) {
do {
- ptr = src + length + k / 2;
+ t_tmp1 = *(src + length + (k >> 1));
+ t_tmp2 = src[j - 1];
if (k & 1) {
- r = c / 8;
- t_table[r + 0] = (src[j - 1] & 0xf0) | t_table[r];
- t_table[r + 1] = ((src[j - 1] & 0x0f) << 4) | (ptr[0] & 0x0f);
+ r = c >> 3;
+ t_table[r + 0] = (t_tmp2 & 0xf0) | t_table[r];
+ t_table[r + 1] = ((t_tmp2 & 0x0f) << 4) | (t_tmp1 & 0x0f);
} else {
- r = s / 8;
- t_table[r + 0] = src[j - 1] >> 4;
- t_table[r - 1] = ((src[j - 1] & 0x0f) << 4) | (ptr[0] >> 4);
+ r = s >> 3;
+ t_table[r + 0] = t_tmp2 >> 4;
+ t_table[r - 1] = ((t_tmp2 & 0x0f) << 4) | (t_tmp1 >> 4);
}
s += 12;
c += 12;
@@ -351,7 +352,7 @@ int32 decompressCodec(int32 codec, byte *comp_input, byte *comp_output, int32 in
memset(t_table, 0, output_size);
src = comp_output;
- length = (output_size * 8) / 12;
+ length = (output_size << 3) / 12;
k = 0;
c = 0;
j = 0;
@@ -361,15 +362,16 @@ int32 decompressCodec(int32 codec, byte *comp_input, byte *comp_output, int32 in
t = length - 1;
if (t > 0) {
do {
- ptr = src + length + k / 2;
+ t_tmp1 = *(src + length + (k >> 1));
+ t_tmp2 = src[j];
if (k & 1) {
- r = s / 8;
- t_table[r + 2] = (src[j] & 0xf0) | *(t_table + r + 2);
- t_table[r + 3] = ((src[j] & 0x0f) << 4) | (ptr[0] >> 4);
+ r = s >> 3;
+ t_table[r + 2] = (t_tmp2 & 0xf0) | t_table[r + 2];
+ t_table[r + 3] = ((t_tmp2 & 0x0f) << 4) | (t_tmp1 >> 4);
} else {
- r = c / 8;
- t_table[r + 2] = src[j] >> 4;
- t_table[r + 1] = ((src[j] & 0x0f) << 4) | (ptr[0] & 0x0f);
+ r = c >> 3;
+ t_table[r + 2] = t_tmp2 >> 4;
+ t_table[r + 1] = ((t_tmp2 & 0x0f) << 4) | (t_tmp1 & 0x0f);
}
s += 12;
c += 12;
@@ -393,36 +395,33 @@ int32 decompressCodec(int32 codec, byte *comp_input, byte *comp_output, int32 in
memcpy(t_table, p, output_size);
offset1 = output_size / 3;
- offset2 = offset1 * 2;
+ offset2 = offset1 << 1;
offset3 = offset2;
src = comp_output;
- do {
- if (offset1 == 0)
- break;
- offset1--;
+
+ while (offset1--) {
offset2 -= 2;
offset3--;
t_table[offset2 + 0] = src[offset1];
t_table[offset2 + 1] = src[offset3];
- } while (1);
+ }
src = comp_output;
- length = (output_size * 8) / 12;
+ length = (output_size << 3) / 12;
k = 0;
if (length > 0) {
c = -12;
s = 0;
do {
- j = length + k / 2;
+ j = length + (k >> 1);
+ t_tmp1 = t_table[k];
if (k & 1) {
- r = c / 8;
- t_tmp1 = t_table[k];
+ r = c >> 3;
t_tmp2 = t_table[j + 1];
src[r + 2] = ((t_tmp1 & 0x0f) << 4) | (t_tmp2 >> 4);
src[r + 1] = (src[r + 1]) | (t_tmp1 & 0xf0);
} else {
- r = s / 8;
- t_tmp1 = t_table[k];
+ r = s >> 3;
t_tmp2 = t_table[j];
src[r + 0] = ((t_tmp1 & 0x0f) << 4) | (t_tmp2 & 0x0f);
src[r + 1] = t_tmp1 >> 4;
@@ -432,7 +431,7 @@ int32 decompressCodec(int32 codec, byte *comp_input, byte *comp_output, int32 in
k++;
} while (k < length);
}
- offset1 = ((length - 1) * 3) / 2;
+ offset1 = ((length - 1) * 3) >> 1;
src[offset1 + 1] = (t_table[length] & 0xf0) | src[offset1 + 1];
free(t_table);
break;
@@ -449,40 +448,36 @@ int32 decompressCodec(int32 codec, byte *comp_input, byte *comp_output, int32 in
memcpy(t_table, p, output_size);
offset1 = output_size / 3;
- offset2 = offset1 * 2;
+ offset2 = offset1 << 1;
offset3 = offset2;
src = comp_output;
- do {
- if (offset1 == 0)
- break;
- offset1--;
+
+ while (offset1--) {
offset2 -= 2;
offset3--;
t_table[offset2 + 0] = src[offset1];
t_table[offset2 + 1] = src[offset3];
- } while (1);
+ }
src = comp_output;
- length = (output_size * 8) / 12;
+ length = (output_size << 3) / 12;
k = 1;
c = 0;
s = 12;
- t_tmp1 = t_table[length] / 16;
+ t_tmp1 = t_table[length] >> 4;
src[0] = t_tmp1;
t = length + k;
if (t > k) {
do {
- j = length + k / 2;
+ j = length + (k >> 1);
+ t_tmp1 = t_table[k - 1];
+ t_tmp2 = t_table[j];
if (k & 1) {
- r = c / 8;
- t_tmp1 = t_table[k - 1];
- t_tmp2 = t_table[j];
+ r = c >> 3;
src[r + 0] = (src[r]) | (t_tmp1 & 0xf0);
src[r + 1] = ((t_tmp1 & 0x0f) << 4) | (t_tmp2 & 0x0f);
} else {
- r = s / 8;
- t_tmp1 = t_table[k - 1];
- t_tmp2 = t_table[j];
+ r = s >> 3;
src[r + 0] = t_tmp1 >> 4;
src[r - 1] = ((t_tmp1 & 0x0f) << 4) | (t_tmp2 >> 4);
}
@@ -506,21 +501,19 @@ int32 decompressCodec(int32 codec, byte *comp_input, byte *comp_output, int32 in
memcpy(t_table, p, output_size);
offset1 = output_size / 3;
- offset2 = offset1 * 2;
+ offset2 = offset1 << 1;
offset3 = offset2;
src = comp_output;
- do {
- if (offset1 == 0)
- break;
- offset1--;
+
+ while (offset1--) {
offset2 -= 2;
offset3--;
t_table[offset2 + 0] = src[offset1];
t_table[offset2 + 1] = src[offset3];
- } while (1);
+ }
src = comp_output;
- length = (output_size * 8) / 12;
+ length = (output_size << 3) / 12;
k = 0;
c = 0;
s = -12;
@@ -529,17 +522,15 @@ int32 decompressCodec(int32 codec, byte *comp_input, byte *comp_output, int32 in
t = length - 1;
if (t > 0) {
do {
- j = length + k / 2;
+ j = length + (k >> 1);
+ t_tmp1 = t_table[k];
+ t_tmp2 = t_table[j];
if (k & 1) {
- r = s / 8;
- t_tmp1 = t_table[k];
- t_tmp2 = t_table[j];
+ r = s >> 3;
src[r + 2] = (src[r + 2]) | (t_tmp1 & 0xf0);
src[r + 3] = ((t_tmp1 & 0x0f) << 4) | (t_tmp2 >> 4);
} else {
- r = c / 8;
- t_tmp1 = t_table[k];
- t_tmp2 = t_table[j];
+ r = c >> 3;
src[r + 2] = t_tmp1 >> 4;
src[r + 1] = ((t_tmp1 & 0x0f) << 4) | (t_tmp2 & 0x0f);
}
@@ -592,8 +583,8 @@ int32 decompressCodec(int32 codec, byte *comp_input, byte *comp_output, int32 in
left = 0x2000 - firstWord;
output_size = left;
} else {
- left = 0x1000 - firstWord / 2;
- output_size = left * 2;
+ left = 0x1000 - (firstWord >> 1);
+ output_size = left << 1;
}
output_size += firstWord;
} else {
@@ -621,38 +612,19 @@ int32 decompressCodec(int32 codec, byte *comp_input, byte *comp_output, int32 in
}
left = origLeft;
- destPos = l * 2;
+ destPos = l << 1;
if (channels == 2) {
if (l == 0)
left++;
- left /= 2;
+ left >>= 1;
}
while (left--) {
curTableEntry = _destImcTable[curTablePos];
decompTable = (byte)(curTableEntry - 2);
bitMask = 2 << decompTable;
- readPos = src + tableEntrySum / 8;
-
- // FIXME - it seems the decoder often reads exactly one byte too
- // far - that is, it reads 2 bytes at once, and the second byte
- // is just outside the buffer. However, it seems of these two bytes,
- // only the upper one is actually used, so this should be fine.
- // Still, I put this error message into place. If somebody one day
- // encounters a situation where the second byte would be used, too,
- // then this would indicate there is a bug in the decoder...
- if (readPos + 1 >= comp_input + input_size) {
- // OK an overflow... if it is more than one byte or if we
- // need more than 8 bit of data -> error
- if (readPos + 1 > comp_input + input_size ||
- curTableEntry + (tableEntrySum & 7) > 8) {
- error("decompressCodec: input buffer overflow: %d bytes over (we need %d bits of data)",
- (int)((readPos + 1) - (comp_input + input_size)) + 1,
- curTableEntry + (tableEntrySum & 7)
- );
- }
- }
+ readPos = src + (tableEntrySum >> 3);
readWord = (uint16)(READ_BE_UINT16(readPos) << (tableEntrySum & 7));
otherTablePos = (byte)(readWord >> (16 - curTableEntry));
tableEntrySum += curTableEntry;
@@ -682,7 +654,7 @@ int32 decompressCodec(int32 codec, byte *comp_input, byte *comp_output, int32 in
curTablePos = 0;
imcTableEntry = imcTable[curTablePos];
- destPos += channels * 2;
+ destPos += channels << 1;
}
}
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-06-13 12:21:10 +0000