- Fixed interframe compression - now works for RLE4 and RLE8.

- Fixed alignment of RLE4 in absolute mode.
- Improved compression (smaller output).
This commit is contained in:
Michael Günnewig 2003-06-30 02:05:44 +00:00 committed by Alexandre Julliard
parent 7be37f4f6b
commit 3ebf9a505f

View file

@ -1,5 +1,5 @@
/*
* Copyright 2002 Michael Günnewig
* Copyright 2002-2003 Michael Günnewig
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@ -17,8 +17,7 @@
*/
/* TODO:
* - compression of RLE4 is buggy -- see FIXME's
* - many improvements possible
* - some improvements possible
* - implement DecompressSetPalette? -- does we need it for anything?
*/
@ -297,10 +296,13 @@ static INT countDiffRLE4(LPWORD lpP, LPWORD lpA, LPWORD lpB, INT pos, LONG lDist
if (ColorCmp(clr1, clr3) <= lDist &&
ColorCmp(clr2, clr4) <= lDist) {
/* diff at end? -- look-ahead for atleast ?? more encodable pixel */
/* FIXME */
return count;
if (pos + 2 < width && ColorCmp(clr1,lpB[pos+1]) <= lDist &&
ColorCmp(clr2,lpB[pos+2]) <= lDist) {
if (pos + 4 < width && ColorCmp(lpB[pos+1],lpB[pos+3]) <= lDist &&
ColorCmp(lpB[pos+2],lpB[pos+4]) <= lDist)
return count - 3; /* followed by atleast 4 encodable pixels */
return count - 2;
}
} else if (lpP != NULL && ColorCmp(lpP[pos], lpB[pos]) <= lDist) {
/* 'compare' with previous frame for end of diff */
INT count2 = 0;
@ -331,9 +333,11 @@ static INT countDiffRLE8(LPWORD lpP, LPWORD lpA, LPWORD lpB, INT pos, LONG lDist
for (count = 0; pos < width; pos++, count++) {
if (ColorCmp(lpA[pos], lpB[pos]) <= lDist) {
/* diff at end? -- look-ahead for atleast one more encodable pixel */
if (pos + 1 < width && ColorCmp(lpA[pos], lpB[pos+1]) <= lDist)
return count;
/* diff at end? -- look-ahead for some more encodable pixel */
if (pos + 1 < width && ColorCmp(lpB[pos], lpB[pos+1]) <= lDist)
return count - 1;
if (pos + 2 < width && ColorCmp(lpB[pos+1], lpB[pos+2]) <= lDist)
return count - 1;
} else if (lpP != NULL && ColorCmp(lpP[pos], lpB[pos]) <= lDist) {
/* 'compare' with previous frame for end of diff */
INT count2 = 0;
@ -382,6 +386,8 @@ static INT MSRLE32_CompressRLE4Line(CodecInfo *pi, LPWORD lpP, LPWORD lpC, LPCBI
/* add some pixel for absoluting if possible */
count += countDiffRLE4(lpP, lpC - 1, lpC, pos-1, lDist, lpbi->biWidth);
assert(count > 0);
/* check for near end of line */
if (x + count > lpbi->biWidth)
count = lpbi->biWidth - x;
@ -390,9 +396,11 @@ static INT MSRLE32_CompressRLE4Line(CodecInfo *pi, LPWORD lpP, LPWORD lpC, LPCBI
while (count > 2) {
INT i;
INT size = min(count, 254);
BOOL extra_byte = (size / 2) % 2 || (size % 2);
int bytes = ((size + 1) & (~1)) / 2;
BOOL extra_byte = bytes & 0x01;
*lpSizeImage += 2 + size/2 + (size % 2) + extra_byte;
*lpSizeImage += 2 + bytes + extra_byte;
assert(((*lpSizeImage) % 2) == 0);
count -= size;
*lpOut++ = 0;
*lpOut++ = size;
@ -468,6 +476,8 @@ static INT MSRLE32_CompressRLE8Line(CodecInfo *pi, LPWORD lpP, LPWORD lpC, LPCBI
/* add some more pixels for absoluting if possible */
count += countDiffRLE8(lpP, lpC - 1, lpC, pos-1, lDist, lpbi->biWidth);
assert(count > 0);
/* check for over end of line */
if (x + count > lpbi->biWidth)
count = lpbi->biWidth - x;
@ -663,6 +673,10 @@ LRESULT MSRLE32_CompressRLE4(CodecInfo *pi, LPBITMAPINFOHEADER lpbiIn, LPBYTE lp
assert(lpOut == lpOutStart + lpbiOut->biSizeImage);
}
}
/* add EOL -- will be changed to EOI */
lpbiOut->biSizeImage += 2;
*((LPWORD)lpOut)++ = 0;
}
/* change EOL to EOI -- end of image */
@ -789,11 +803,14 @@ LRESULT MSRLE32_CompressRLE8(CodecInfo *pi, LPBITMAPINFOHEADER lpbiIn, LPBYTE lp
if (jumpy == 0) {
/* add EOL -- end of line */
lpbiOut->biSizeImage += 2;
*lpOut++ = 0;
*lpOut++ = 0;
*((LPDWORD)lpOut)++ = 0;
assert(lpOut == (lpOutStart + lpbiOut->biSizeImage));
}
}
/* add EOL -- will be changed to EOI */
lpbiOut->biSizeImage += 2;
*((LPDWORD)lpOut)++ = 0;
}
/* change EOL to EOI -- end of image */
@ -847,7 +864,7 @@ static LRESULT MSRLE32_DecompressRLE4(CodecInfo *pi, LPCBITMAPINFOHEADER lpbi,
}
break;
default: /* absolute mode */
extra_byte = (code1 / 2) & 0x01 || (code1 % 2);
extra_byte = (((code1 + 1) & (~1)) / 2) & 0x01;
if (pixel_ptr/bytes_per_pixel + code1 > lpbi->biWidth)
return ICERR_ERROR;
@ -1468,9 +1485,7 @@ static LRESULT Compress(CodecInfo *pi, ICCOMPRESS* lpic, DWORD dwSize)
if (lpic->lpbiOutput->biBitCount == 4)
MSRLE32_CompressRLE4(pi, lpic->lpbiInput, (LPBYTE)lpic->lpInput,
lpic->lpbiOutput, (LPBYTE)lpic->lpOutput, TRUE);
/*MSRLE32_CompressRLE4(pi, lpic->lpbiInput, (LPBYTE)lpic->lpInput,
lpic->lpbiOutput, (LPBYTE)lpic->lpOutput, (lpic->dwFlags & ICCOMPRESS_KEYFRAME) != 0);*/
lpic->lpbiOutput, (LPBYTE)lpic->lpOutput, (lpic->dwFlags & ICCOMPRESS_KEYFRAME) != 0);
else
MSRLE32_CompressRLE8(pi, lpic->lpbiInput, (LPBYTE)lpic->lpInput,
lpic->lpbiOutput, (LPBYTE)lpic->lpOutput, (lpic->dwFlags & ICCOMPRESS_KEYFRAME) != 0);