void qacWriteNext(FILE *f, struct qaSeq *qa)
/* Write next record to qac file. */
{
int cBufSize = qa->size + (qa->size>>1);
signed char *cBuf = needLargeMem(cBufSize);
bits32 cSize, origSize;
origSize = qa->size;
cSize = rleCompress(qa->qa, qa->size, cBuf);
writeString(f, qa->name);
writeOne(f, origSize);
writeOne(f, cSize);
mustWrite(f, cBuf, cSize);
freeMem(cBuf);
}
int
RleCompressor::compress (const char *inPtr,
int inSize,
int minY,
const char *&outPtr)
{
//
// Special case - empty input buffer
//
if (inSize == 0)
{
outPtr = _outBuffer;
return 0;
}
//
// Reorder the pixel data.
//
{
char *t1 = _tmpBuffer;
char *t2 = _tmpBuffer + (inSize + 1) / 2;
const char *stop = inPtr + inSize;
while (true)
{
if (inPtr < stop)
*(t1++) = *(inPtr++);
else
break;
if (inPtr < stop)
*(t2++) = *(inPtr++);
else
break;
}
}
//
// Predictor.
//
{
unsigned char *t = (unsigned char *) _tmpBuffer + 1;
unsigned char *stop = (unsigned char *) _tmpBuffer + inSize;
int p = t[-1];
while (t < stop)
{
int d = int (t[0]) - p + (128 + 256);
p = t[0];
t[0] = d;
++t;
}
}
//
// Run-length encode the data.
//
outPtr = _outBuffer;
return rleCompress (inSize, _tmpBuffer, (signed char *) _outBuffer);
}
