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more simplifications

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Originally committed as revision 5795 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2006-07-19 22:21:45 +00:00
parent f72f8a7735
commit 006ff1cabe
1 changed files with 29 additions and 39 deletions
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68
libavcodec/vp3.c
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@ -1369,9 +1369,6 @@ static void reverse_dc_prediction(Vp3DecodeContext *s,
short predicted_dc;
/* validity flags for the left, up-left, up, and up-right fragments */
int fl, ful, fu, fur;
/* DC values for the left, up-left, up, and up-right fragments */
int vl, vul, vu, vur;
@ -1384,26 +1381,24 @@ static void reverse_dc_prediction(Vp3DecodeContext *s,
* 1: up multiplier
* 2: up-right multiplier
* 3: left multiplier
* 4: mask
* 5: right bit shift divisor (e.g., 7 means >>=7, a.k.a. div by 128)
*/
int predictor_transform[16][6] = {
{ 0, 0, 0, 0, 0, 0 },
{ 0, 0, 0, 1, 0, 0 }, // PL
{ 0, 0, 1, 0, 0, 0 }, // PUR
{ 0, 0, 53, 75, 127, 7 }, // PUR|PL
{ 0, 1, 0, 0, 0, 0 }, // PU
{ 0, 1, 0, 1, 1, 1 }, // PU|PL
{ 0, 1, 0, 0, 0, 0 }, // PU|PUR
{ 0, 0, 53, 75, 127, 7 }, // PU|PUR|PL
{ 1, 0, 0, 0, 0, 0 }, // PUL
{ 0, 0, 0, 1, 0, 0 }, // PUL|PL
{ 1, 0, 1, 0, 1, 1 }, // PUL|PUR
{ 0, 0, 53, 75, 127, 7 }, // PUL|PUR|PL
{ 0, 1, 0, 0, 0, 0 }, // PUL|PU
{-26, 29, 0, 29, 31, 5 }, // PUL|PU|PL
{ 3, 10, 3, 0, 15, 4 }, // PUL|PU|PUR
{-26, 29, 0, 29, 31, 5 } // PUL|PU|PUR|PL
int predictor_transform[16][4] = {
{ 0, 0, 0, 0},
{ 0, 0, 0,128}, // PL
{ 0, 0,128, 0}, // PUR
{ 0, 0, 53, 75}, // PUR|PL
{ 0,128, 0, 0}, // PU
{ 0, 64, 0, 64}, // PU|PL
{ 0,128, 0, 0}, // PU|PUR
{ 0, 0, 53, 75}, // PU|PUR|PL
{128, 0, 0, 0}, // PUL
{ 0, 0, 0,128}, // PUL|PL
{ 64, 0, 64, 0}, // PUL|PUR
{ 0, 0, 53, 75}, // PUL|PUR|PL
{ 0,128, 0, 0}, // PUL|PU
{-104,116, 0,116}, // PUL|PU|PL
{ 24, 80, 24, 0}, // PUL|PU|PUR
{-104,116, 0,116} // PUL|PU|PUR|PL
};
/* This table shows which types of blocks can use other blocks for
@ -1445,32 +1440,32 @@ static void reverse_dc_prediction(Vp3DecodeContext *s,
current_frame_type =
compatible_frame[s->all_fragments[i].coding_method];
debug_dc_pred(" frag %d: group %d, orig DC = %d, ",
i, -1, DC_COEFF(i));
debug_dc_pred(" frag %d: orig DC = %d, ",
i, DC_COEFF(i));
transform= 0;
if(x){
l= i-1;
vl = DC_COEFF(l);
fl = FRAME_CODED(l) && COMPATIBLE_FRAME(l);
transform |= fl*PL;
if(FRAME_CODED(l) && COMPATIBLE_FRAME(l))
transform |= PL;
}
if(y){
u= i-fragment_width;
vu = DC_COEFF(u);
fu = FRAME_CODED(u) && COMPATIBLE_FRAME(u);
transform |= fu*PU;
if(FRAME_CODED(u) && COMPATIBLE_FRAME(u))
transform |= PU;
if(x){
ul= i-fragment_width-1;
vul = DC_COEFF(ul);
ful = FRAME_CODED(ul) && COMPATIBLE_FRAME(ul);
transform |= ful*PUL;
if(FRAME_CODED(ul) && COMPATIBLE_FRAME(ul))
transform |= PUL;
}
if(x + 1 < fragment_width){
ur= i-fragment_width+1;
vur = DC_COEFF(ur);
fur = FRAME_CODED(ur) && COMPATIBLE_FRAME(ur);
transform |= fur*PUR;
if(FRAME_CODED(ur) && COMPATIBLE_FRAME(ur))
transform |= PUR;
}
}
@ -1493,13 +1488,8 @@ static void reverse_dc_prediction(Vp3DecodeContext *s,
(predictor_transform[transform][2] * vur) +
(predictor_transform[transform][3] * vl);
/* if there is a shift value in the transform, add
* the sign bit before the shift */
if (predictor_transform[transform][5] != 0) {
predicted_dc += ((predicted_dc >> 15) &
predictor_transform[transform][4]);
predicted_dc >>= predictor_transform[transform][5];
}
predicted_dc += (predicted_dc >> 15) & 127;
predicted_dc >>= 7;
/* check for outranging on the [ul u l] and
* [ul u ur l] predictors */