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Back to classic pixmix/pixmix2 architecture. Probably made some parts clearer. More and more correct documentation of the Draw code. Probably more correct (at least not less correct, it seems) alpha calculation.

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Originally committed to SVN as r1543.
This commit is contained in:
Niels Martin Hansen 2007-08-29 19:57:16 +00:00
parent 35f2b7caa2
commit 268b6c45af
1 changed files with 61 additions and 56 deletions
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117
vsfilter/subtitles/Rasterizer.cpp
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@ -773,8 +773,21 @@ bool Rasterizer::Rasterize(int xsub, int ysub, bool fBlur)
static __forceinline void pixmix(DWORD *dst, DWORD color, DWORD alpha)
{
int a = (((alpha)*(color>>24))>>12)&0xff;
int a = (((alpha)*(color>>24))>>6)&0xff;
// Make sure both a and ia are in range 1..256 for the >>8 operations below to be correct
int ia = 256-a;
a+=1;
*dst = ((((*dst&0x00ff00ff)*ia + (color&0x00ff00ff)*a)&0xff00ff00)>>8)
| ((((*dst&0x0000ff00)*ia + (color&0x0000ff00)*a)&0x00ff0000)>>8)
| ((((*dst>>8)&0x00ff0000)*ia)&0xff000000);
}
static __forceinline void pixmix2(DWORD *dst, DWORD color, DWORD shapealpha, DWORD clipalpha)
{
int a = (((shapealpha)*(clipalpha)*(color>>24))>>12)&0xff;
int ia = 256-a;
a+=1;
*dst = ((((*dst&0x00ff00ff)*ia + (color&0x00ff00ff)*a)&0xff00ff00)>>8)
| ((((*dst&0x0000ff00)*ia + (color&0x0000ff00)*a)&0x00ff0000)>>8)
@ -786,11 +799,30 @@ static __forceinline void pixmix(DWORD *dst, DWORD color, DWORD alpha)
static __forceinline void pixmix_sse2(DWORD* dst, DWORD color, DWORD alpha)
{
alpha = ((alpha * (color>>24)) >> 12) & 0xff;
alpha = (((alpha) * (color>>24)) >> 6) & 0xff;
color &= 0xffffff;
__m128i zero = _mm_setzero_si128();
__m128i a = _mm_set1_epi32((alpha << 16) | (0x100 - alpha));
__m128i a = _mm_set1_epi32(((alpha+1) << 16) | (0x100 - alpha));
__m128i d = _mm_unpacklo_epi8(_mm_cvtsi32_si128(*dst), zero);
__m128i s = _mm_unpacklo_epi8(_mm_cvtsi32_si128(color), zero);
__m128i r = _mm_unpacklo_epi16(d, s);
r = _mm_madd_epi16(r, a);
r = _mm_srli_epi32(r, 8);
r = _mm_packs_epi32(r, r);
r = _mm_packus_epi16(r, r);
*dst = (DWORD)_mm_cvtsi128_si32(r);
}
static __forceinline void pixmix2_sse2(DWORD* dst, DWORD color, DWORD shapealpha, DWORD clipalpha)
{
int alpha = (((shapealpha)*(clipalpha)*(color>>24))>>12)&0xff;
color &= 0xffffff;
__m128i zero = _mm_setzero_si128();
__m128i a = _mm_set1_epi32(((alpha+1) << 16) | (0x100 - alpha));
__m128i d = _mm_unpacklo_epi8(_mm_cvtsi32_si128(*dst), zero);
__m128i s = _mm_unpacklo_epi8(_mm_cvtsi32_si128(color), zero);
__m128i r = _mm_unpacklo_epi16(d, s);
@ -813,7 +845,8 @@ static const __int64 _00ff00ff00ff00ff = 0x00ff00ff00ff00ffi64;
// clipRect is a rectangular clip region to render inside.
// pAlphaMask is an alpha clipping mask.
// xsub and ysub ???
// switchpts seems to be an array of interlaced colour switching coordinates/colours to switch to.
// switchpts seems to be an array of fill colours interlaced with coordinates.
// switchpts[i*2] contains a colour and switchpts[i*2+1] contains the coordinate to use that colour from
// fBody tells whether to render the body of the subs.
// fBorder tells whether to render the border of the subs.
CRect Rasterizer::Draw(SubPicDesc& spd, CRect& clipRect, byte* pAlphaMask, int xsub, int ysub, const long* switchpts, bool fBody, bool fBorder)
@ -853,13 +886,16 @@ CRect Rasterizer::Draw(SubPicDesc& spd, CRect& clipRect, byte* pAlphaMask, int x
// The alpha bitmap of the subtitles?
const byte* src = mpOverlayBuffer + 2*(mOverlayWidth * yo + xo);
// s points to what the "body" to use is
// If we're rendering body fill and border, src+1 points to the array of
// widened regions which contain both border and fill in one.
const byte* s = fBorder ? (src+1) : src;
// The complex "vector clip mask" I think.
const byte* am = pAlphaMask + spd.w * y + x;
// How would this differ from src?
unsigned long* dst = (unsigned long *)((char *)spd.bits + spd.pitch * y) + x;
// ??? What is switchpts ?
// Grab the first colour
unsigned long color = switchpts[0];
// CPUID from VDub
@ -871,23 +907,24 @@ CRect Rasterizer::Draw(SubPicDesc& spd, CRect& clipRect, byte* pAlphaMask, int x
// Basic case of no complex clipping mask
if(!pAlphaMask)
{
// Again, what is switchpts?
// If the first colour switching coordinate is at "infinite" we're
// never switching and can use some simpler code.
// ??? Is this optimisation really worth the extra readability issues it adds?
if(switchpts[1] == 0xffffffff)
{
// Are we rendering the fill or a border/shadow? I think...
// fBody is true if we're rendering a fill or a shadow.
if(fBody)
{
// Run over every pixel, overlaying the subtitles with the fill colour
if(fSSE2)
for(int wt=0; wt<w; ++wt)
// Why s[wt*2] and not s[wt] ?
// The <<6 is due to pixmix expecting the alpha parameter to be
// the multiplication of two 6-bit unsigned numbers but we
// only have one here. (No alpha mask.)
pixmix_sse2(&dst[wt], color, s[wt*2]<<6);
pixmix_sse2(&dst[wt], color, s[wt*2]);
else
for(int wt=0; wt<w; ++wt)
pixmix(&dst[wt], color, s[wt*2]<<6);
pixmix(&dst[wt], color, s[wt*2]);
}
// Not body, ie. something else (border, shadow, I guess)
else
@ -902,10 +939,10 @@ CRect Rasterizer::Draw(SubPicDesc& spd, CRect& clipRect, byte* pAlphaMask, int x
// created by CreateWidenedRegion, and thus contains
// both the fill and the border, so subtracting the fill
// from that is always safe.
pixmix_sse2(&dst[wt], color, (src[wt*2+1] - src[wt*2])<<6);
pixmix_sse2(&dst[wt], color, src[wt*2+1] - src[wt*2]);
else
for(int wt=0; wt<w; ++wt)
pixmix(&dst[wt], color, (src[wt*2+1] - src[wt*2])<<6);
pixmix(&dst[wt], color, src[wt*2+1] - src[wt*2]);
}
}
// not (switchpts[1] == 0xffffffff)
@ -923,13 +960,13 @@ CRect Rasterizer::Draw(SubPicDesc& spd, CRect& clipRect, byte* pAlphaMask, int x
// So if we have passed the switchpoint (?) switch to another colour
// (So switchpts stores both colours *and* coordinates?)
if(wt+xo >= sw[1]) {while(wt+xo >= sw[1]) sw += 2; color = sw[-2];}
pixmix_sse2(&dst[wt], color, s[wt*2]<<6);
pixmix_sse2(&dst[wt], color, s[wt*2]);
}
else
for(int wt=0; wt<w; ++wt)
{
if(wt+xo >= sw[1]) {while(wt+xo >= sw[1]) sw += 2; color = sw[-2];}
pixmix(&dst[wt], color, s[wt*2]<<6);
pixmix(&dst[wt], color, s[wt*2]);
}
}
// Not body
@ -939,13 +976,13 @@ CRect Rasterizer::Draw(SubPicDesc& spd, CRect& clipRect, byte* pAlphaMask, int x
for(int wt=0; wt<w; ++wt)
{
if(wt+xo >= sw[1]) {while(wt+xo >= sw[1]) sw += 2; color = sw[-2];}
pixmix_sse2(&dst[wt], color, (src[wt*2+1] - src[wt*2])<<6);
pixmix_sse2(&dst[wt], color, src[wt*2+1] - src[wt*2]);
}
else
for(int wt=0; wt<w; ++wt)
{
if(wt+xo >= sw[1]) {while(wt+xo >= sw[1]) sw += 2; color = sw[-2];}
pixmix(&dst[wt], color, (src[wt*2+1] - src[wt*2])<<6);
pixmix(&dst[wt], color, src[wt*2+1] - src[wt*2]);
}
}
}
@ -957,12 +994,6 @@ CRect Rasterizer::Draw(SubPicDesc& spd, CRect& clipRect, byte* pAlphaMask, int x
{
if(fBody)
{
/*const byte* s = fBorder?(src+1):src;
for(int wt=0; wt<w; ++wt)
{
pixmix2(s[wt*2]);
}*/
if(fSSE2)
for(int wt=0; wt<w; ++wt)
// Both s and am contain 6-bit bitmaps of two different
@ -970,23 +1001,19 @@ CRect Rasterizer::Draw(SubPicDesc& spd, CRect& clipRect, byte* pAlphaMask, int x
// clipping mask.
// Multiplying them together yields a 12-bit number.
// I think some imprecision is introduced here??
pixmix_sse2(&dst[wt], color, s[wt*2] * am[wt]);
pixmix2_sse2(&dst[wt], color, s[wt*2], am[wt]);
else
for(int wt=0; wt<w; ++wt)
pixmix(&dst[wt], color, s[wt*2] * am[wt]);
pixmix2(&dst[wt], color, s[wt*2], am[wt]);
}
else
{
/*for(int wt=0; wt<w; ++wt)
{
pixmix2(src[wt*2+1]-src[wt*2]);
}*/
if(fSSE2)
for(int wt=0; wt<w; ++wt)
pixmix_sse2(&dst[wt], color, (src[wt*2+1] - src[wt*2]) * am[wt]);
pixmix2_sse2(&dst[wt], color, src[wt*2+1] - src[wt*2], am[wt]);
else
for(int wt=0; wt<w; ++wt)
pixmix(&dst[wt], color, (src[wt*2+1] - src[wt*2]) * am[wt]);
pixmix2(&dst[wt], color, src[wt*2+1] - src[wt*2], am[wt]);
}
}
else
@ -995,18 +1022,6 @@ CRect Rasterizer::Draw(SubPicDesc& spd, CRect& clipRect, byte* pAlphaMask, int x
if(fBody)
{
/*const byte* s = fBorder?(src+1):src;
for(int wt=0; wt<w; ++wt)
{
if(wt+xo >= sw[1])
{
while(wt+xo >= sw[1]) sw += 2;
color = sw[-2];
}
pixmix2(s[wt*2]);
}*/
if(fSSE2)
for(int wt=0; wt<w; ++wt)
{
@ -1014,7 +1029,7 @@ CRect Rasterizer::Draw(SubPicDesc& spd, CRect& clipRect, byte* pAlphaMask, int x
while(wt+xo >= sw[1])
sw += 2; color = sw[-2];
}
pixmix_sse2(&dst[wt], color, s[wt*2] * am[wt]);
pixmix2_sse2(&dst[wt], color, s[wt*2], am[wt]);
}
else
for(int wt=0; wt<w; ++wt)
@ -1023,21 +1038,11 @@ CRect Rasterizer::Draw(SubPicDesc& spd, CRect& clipRect, byte* pAlphaMask, int x
while(wt+xo >= sw[1])
sw += 2; color = sw[-2];
}
pixmix(&dst[wt], color, s[wt*2] * am[wt]);
pixmix2(&dst[wt], color, s[wt*2], am[wt]);
}
}
else
{
/*for(int wt=0; wt<w; ++wt)
{
if(wt+xo >= sw[1])
{
while(wt+xo >= sw[1]) sw += 2;
color = sw[-2];
}
pixmix2(src[wt*2+1]-src[wt*2]);
}*/
if(fSSE2)
for(int wt=0; wt<w; ++wt)
{
@ -1045,7 +1050,7 @@ CRect Rasterizer::Draw(SubPicDesc& spd, CRect& clipRect, byte* pAlphaMask, int x
while(wt+xo >= sw[1])
sw += 2; color = sw[-2];
}
pixmix_sse2(&dst[wt], color, (src[wt*2+1] - src[wt*2]) * am[wt]);
pixmix2_sse2(&dst[wt], color, src[wt*2+1] - src[wt*2], am[wt]);
}
else
for(int wt=0; wt<w; ++wt)
@ -1054,7 +1059,7 @@ CRect Rasterizer::Draw(SubPicDesc& spd, CRect& clipRect, byte* pAlphaMask, int x
while(wt+xo >= sw[1])
sw += 2; color = sw[-2];
}
pixmix(&dst[wt], color, (src[wt*2+1] - src[wt*2]) * am[wt]);
pixmix2(&dst[wt], color, src[wt*2+1] - src[wt*2], am[wt]);
}
}
}