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Bitstream fixes

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This commit is contained in:
Jack Andersen
2017-02-05 17:21:58 -10:00
parent 1c86d0ac93
commit 6a7fc0145f
26 changed files with 268 additions and 120 deletions
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138
Runtime/IOStreams.cpp
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@@ -1,7 +1,21 @@
#include "IOStreams.hpp"
#include "hecl/hecl.hpp"
namespace urde
{
#define DUMP_BITS 0
#if DUMP_BITS
static void PrintBinary(u32 val, u32 count)
{
for (int i=0 ; i<count ; ++i)
{
printf("%d", (val >> (count-i-1)) & 0x1);
}
}
#endif
/*!
* \brief CBitStreamReader::ReadBit
* Reads and decodes an encoded value from a bitstream.
@@ -10,91 +24,95 @@ namespace urde
*/
s32 CBitStreamReader::ReadEncoded(u32 bitCount)
{
s32 ret = 0;
if (bitCount < x20_bitOffset)
#if DUMP_BITS
auto pos = position();
auto boff = x20_bitOffset;
#endif
u32 ret = 0;
s32 shiftAmt = x20_bitOffset - s32(bitCount);
if (shiftAmt < 0)
{
u32 diff = 0x20 - bitCount;
u32 baseVal = -1;
if (x20_bitOffset != 0x20)
baseVal = (1 << bitCount) - 1;
x20_bitOffset -= bitCount;
ret = baseVal & (x1c_val >> diff);
x1c_val <<= bitCount;
/* OR in remaining bits of cached value */
u32 mask = (1 << bitCount) - 1;
ret |= (x1c_val << -shiftAmt) & mask;
/* Load in exact number of bytes remaining */
auto loadDiv = std::div(-shiftAmt, 8);
if (loadDiv.rem) ++loadDiv.quot;
readUBytesToBuf(reinterpret_cast<u8*>(&x1c_val) + 4 - loadDiv.quot, loadDiv.quot);
x1c_val = hecl::SBig(x1c_val);
/* New bit offset */
x20_bitOffset = loadDiv.quot * 8 + shiftAmt;
/* OR in next bits */
mask = (1 << -shiftAmt) - 1;
ret |= (x1c_val >> x20_bitOffset) & mask;
}
else
{
u32 diff = bitCount - x20_bitOffset;
u32 baseVal = -1;
if (x20_bitOffset != 32)
baseVal = (1 << x20_bitOffset) - 1;
/* OR in bits of cached value */
u32 mask = (1 << bitCount) - 1;
ret |= (x1c_val >> shiftAmt) & mask;
baseVal = (baseVal & (x1c_val >> (32 - x20_bitOffset))) << diff;
x20_bitOffset = 0;
auto pos = std::div(diff, 8);
if (pos.rem) ++pos.quot;
readUBytesToBuf(&x1c_val, pos.quot);
/* The game uses Big Endian, which doesn't work for us */
/* Little Endian sucks */
athena::utility::BigUint32(x1c_val);
u32 baseVal2 = -1;
if (diff != 32)
baseVal2 = (1 << diff) - 1;
ret = baseVal | (baseVal2 & (x1c_val >> (32 - diff))) << x20_bitOffset;
x20_bitOffset = (pos.quot << 3) - diff;
x1c_val <<= diff;
/* New bit offset */
x20_bitOffset -= bitCount;
}
#if DUMP_BITS
printf("READ ");
PrintBinary(ret, bitCount);
printf(" %d %d\n", int(pos), int(boff));
#endif
return ret;
}
void CBitStreamWriter::WriteEncoded(u32 val, u32 bitCount)
{
if (x18_bitOffset >= bitCount)
#if DUMP_BITS
printf("WRITE ");
PrintBinary(val, bitCount);
printf(" %d %d\n", int(position()), int(x18_bitOffset));
#endif
s32 shiftAmt = x18_bitOffset - s32(bitCount);
if (shiftAmt < 0)
{
int baseVal = -1;
if (bitCount != 32)
baseVal = (1 << bitCount) - 1;
x14_val |= (val & baseVal) << (x18_bitOffset - bitCount);
x18_bitOffset -= bitCount;
/* OR remaining bits to cached value */
u32 mask = (1 << x18_bitOffset) - 1;
x14_val |= (val >> -shiftAmt) & mask;
/* Write out 32-bits */
x14_val = hecl::SBig(x14_val);
writeUBytes(reinterpret_cast<u8*>(&x14_val), 4);
/* Cache remaining bits */
x18_bitOffset = 0x20 + shiftAmt;
x14_val = val << x18_bitOffset;
}
else
{
u32 diff = bitCount - x18_bitOffset;
u32 baseVal = -1;
if (x18_bitOffset != 32)
baseVal = (1 << x18_bitOffset) - 1;
/* OR bits to cached value */
u32 mask = (1 << bitCount) - 1;
x14_val |= (val & mask) << shiftAmt;
x14_val |= (val >> diff) & baseVal;
x18_bitOffset = 0;
u32 tmp = x14_val;
athena::utility::BigUint32(tmp);
auto pos = std::div(32 - x18_bitOffset, 8);
if (pos.rem) ++pos.quot;
writeBytes(&tmp, pos.quot);
u32 rem = 32 - diff;
baseVal = -1;
if (diff != 32)
baseVal = (1 << diff) - 1;
x14_val = (val & baseVal) << rem;
x18_bitOffset -= diff;
/* New bit offset */
x18_bitOffset -= bitCount;
}
}
void CBitStreamWriter::Flush()
{
if (x18_bitOffset && x18_bitOffset < 0x20)
if (x18_bitOffset < 0x20)
{
u32 tmp = x14_val;
athena::utility::BigUint32(tmp);
auto pos = std::div(32 - x18_bitOffset, 8);
auto pos = std::div(0x20 - x18_bitOffset, 8);
if (pos.rem) ++pos.quot;
writeBytes(&tmp, pos.quot);
x18_bitOffset = 32;
x14_val = hecl::SBig(x14_val);
writeUBytes(reinterpret_cast<u8*>(&x14_val), pos.quot);
x18_bitOffset = 0x20;
x14_val = 0;
}
}