diff options
Diffstat (limited to 'gst-libs/gst/idct/fastintidct.c')
| -rw-r--r-- | gst-libs/gst/idct/fastintidct.c | 156 |
1 files changed, 80 insertions, 76 deletions
diff --git a/gst-libs/gst/idct/fastintidct.c b/gst-libs/gst/idct/fastintidct.c index 27426672..9bb1436d 100644 --- a/gst-libs/gst/idct/fastintidct.c +++ b/gst-libs/gst/idct/fastintidct.c @@ -45,17 +45,17 @@ /* this code assumes >> to be a two's-complement arithmetic */ /* right shift: (-2)>>1 == -1 , (-3)>>1 == -2 */ -#define W1 2841 /* 2048*sqrt(2)*cos(1*pi/16) */ -#define W2 2676 /* 2048*sqrt(2)*cos(2*pi/16) */ -#define W3 2408 /* 2048*sqrt(2)*cos(3*pi/16) */ -#define W5 1609 /* 2048*sqrt(2)*cos(5*pi/16) */ -#define W6 1108 /* 2048*sqrt(2)*cos(6*pi/16) */ -#define W7 565 /* 2048*sqrt(2)*cos(7*pi/16) */ +#define W1 2841 /* 2048*sqrt(2)*cos(1*pi/16) */ +#define W2 2676 /* 2048*sqrt(2)*cos(2*pi/16) */ +#define W3 2408 /* 2048*sqrt(2)*cos(3*pi/16) */ +#define W5 1609 /* 2048*sqrt(2)*cos(5*pi/16) */ +#define W6 1108 /* 2048*sqrt(2)*cos(6*pi/16) */ +#define W7 565 /* 2048*sqrt(2)*cos(7*pi/16) */ #include "dct.h" /* private data */ -static short iclip[1024]; /* clipping table */ +static short iclip[1024]; /* clipping table */ static short *iclp; /* private prototypes */ @@ -72,57 +72,58 @@ static void idctcol (short *blk); * c[1..7] = 128*sqrt(2) */ -static void idctrow(blk) -short *blk; +static void +idctrow (blk) + short *blk; { int x0, x1, x2, x3, x4, x5, x6, x7, x8; /* shortcut */ - if (!((x1 = blk[4]<<11) | (x2 = blk[6]) | (x3 = blk[2]) | - (x4 = blk[1]) | (x5 = blk[7]) | (x6 = blk[5]) | (x7 = blk[3]))) - { - blk[0]=blk[1]=blk[2]=blk[3]=blk[4]=blk[5]=blk[6]=blk[7]=blk[0]<<3; + if (!((x1 = blk[4] << 11) | (x2 = blk[6]) | (x3 = blk[2]) | + (x4 = blk[1]) | (x5 = blk[7]) | (x6 = blk[5]) | (x7 = blk[3]))) { + blk[0] = blk[1] = blk[2] = blk[3] = blk[4] = blk[5] = blk[6] = blk[7] = + blk[0] << 3; return; } - x0 = (blk[0]<<11) + 128; /* for proper rounding in the fourth stage */ + x0 = (blk[0] << 11) + 128; /* for proper rounding in the fourth stage */ /* first stage */ - x8 = W7*(x4+x5); - x4 = x8 + (W1-W7)*x4; - x5 = x8 - (W1+W7)*x5; - x8 = W3*(x6+x7); - x6 = x8 - (W3-W5)*x6; - x7 = x8 - (W3+W5)*x7; - + x8 = W7 * (x4 + x5); + x4 = x8 + (W1 - W7) * x4; + x5 = x8 - (W1 + W7) * x5; + x8 = W3 * (x6 + x7); + x6 = x8 - (W3 - W5) * x6; + x7 = x8 - (W3 + W5) * x7; + /* second stage */ x8 = x0 + x1; x0 -= x1; - x1 = W6*(x3+x2); - x2 = x1 - (W2+W6)*x2; - x3 = x1 + (W2-W6)*x3; + x1 = W6 * (x3 + x2); + x2 = x1 - (W2 + W6) * x2; + x3 = x1 + (W2 - W6) * x3; x1 = x4 + x6; x4 -= x6; x6 = x5 + x7; x5 -= x7; - + /* third stage */ x7 = x8 + x3; x8 -= x3; x3 = x0 + x2; x0 -= x2; - x2 = (181*(x4+x5)+128)>>8; - x4 = (181*(x4-x5)+128)>>8; - + x2 = (181 * (x4 + x5) + 128) >> 8; + x4 = (181 * (x4 - x5) + 128) >> 8; + /* fourth stage */ - blk[0] = (x7+x1)>>8; - blk[1] = (x3+x2)>>8; - blk[2] = (x0+x4)>>8; - blk[3] = (x8+x6)>>8; - blk[4] = (x8-x6)>>8; - blk[5] = (x0-x4)>>8; - blk[6] = (x3-x2)>>8; - blk[7] = (x7-x1)>>8; + blk[0] = (x7 + x1) >> 8; + blk[1] = (x3 + x2) >> 8; + blk[2] = (x0 + x4) >> 8; + blk[3] = (x8 + x6) >> 8; + blk[4] = (x8 - x6) >> 8; + blk[5] = (x0 - x4) >> 8; + blk[6] = (x3 - x2) >> 8; + blk[7] = (x7 - x1) >> 8; } /* column (vertical) IDCT @@ -134,78 +135,81 @@ short *blk; * where: c[0] = 1/1024 * c[1..7] = (1/1024)*sqrt(2) */ -static void idctcol(blk) -short *blk; +static void +idctcol (blk) + short *blk; { int x0, x1, x2, x3, x4, x5, x6, x7, x8; /* shortcut */ - if (!((x1 = (blk[8*4]<<8)) | (x2 = blk[8*6]) | (x3 = blk[8*2]) | - (x4 = blk[8*1]) | (x5 = blk[8*7]) | (x6 = blk[8*5]) | (x7 = blk[8*3]))) - { - blk[8*0]=blk[8*1]=blk[8*2]=blk[8*3]=blk[8*4]=blk[8*5]=blk[8*6]=blk[8*7]= - iclp[(blk[8*0]+32)>>6]; + if (!((x1 = (blk[8 * 4] << 8)) | (x2 = blk[8 * 6]) | (x3 = blk[8 * 2]) | + (x4 = blk[8 * 1]) | (x5 = blk[8 * 7]) | (x6 = blk[8 * 5]) | (x7 = + blk[8 * 3]))) { + blk[8 * 0] = blk[8 * 1] = blk[8 * 2] = blk[8 * 3] = blk[8 * 4] = + blk[8 * 5] = blk[8 * 6] = blk[8 * 7] = iclp[(blk[8 * 0] + 32) >> 6]; return; } - x0 = (blk[8*0]<<8) + 8192; + x0 = (blk[8 * 0] << 8) + 8192; /* first stage */ - x8 = W7*(x4+x5) + 4; - x4 = (x8+(W1-W7)*x4)>>3; - x5 = (x8-(W1+W7)*x5)>>3; - x8 = W3*(x6+x7) + 4; - x6 = (x8-(W3-W5)*x6)>>3; - x7 = (x8-(W3+W5)*x7)>>3; - + x8 = W7 * (x4 + x5) + 4; + x4 = (x8 + (W1 - W7) * x4) >> 3; + x5 = (x8 - (W1 + W7) * x5) >> 3; + x8 = W3 * (x6 + x7) + 4; + x6 = (x8 - (W3 - W5) * x6) >> 3; + x7 = (x8 - (W3 + W5) * x7) >> 3; + /* second stage */ x8 = x0 + x1; x0 -= x1; - x1 = W6*(x3+x2) + 4; - x2 = (x1-(W2+W6)*x2)>>3; - x3 = (x1+(W2-W6)*x3)>>3; + x1 = W6 * (x3 + x2) + 4; + x2 = (x1 - (W2 + W6) * x2) >> 3; + x3 = (x1 + (W2 - W6) * x3) >> 3; x1 = x4 + x6; x4 -= x6; x6 = x5 + x7; x5 -= x7; - + /* third stage */ x7 = x8 + x3; x8 -= x3; x3 = x0 + x2; x0 -= x2; - x2 = (181*(x4+x5)+128)>>8; - x4 = (181*(x4-x5)+128)>>8; - + x2 = (181 * (x4 + x5) + 128) >> 8; + x4 = (181 * (x4 - x5) + 128) >> 8; + /* fourth stage */ - blk[8*0] = iclp[(x7+x1)>>14]; - blk[8*1] = iclp[(x3+x2)>>14]; - blk[8*2] = iclp[(x0+x4)>>14]; - blk[8*3] = iclp[(x8+x6)>>14]; - blk[8*4] = iclp[(x8-x6)>>14]; - blk[8*5] = iclp[(x0-x4)>>14]; - blk[8*6] = iclp[(x3-x2)>>14]; - blk[8*7] = iclp[(x7-x1)>>14]; + blk[8 * 0] = iclp[(x7 + x1) >> 14]; + blk[8 * 1] = iclp[(x3 + x2) >> 14]; + blk[8 * 2] = iclp[(x0 + x4) >> 14]; + blk[8 * 3] = iclp[(x8 + x6) >> 14]; + blk[8 * 4] = iclp[(x8 - x6) >> 14]; + blk[8 * 5] = iclp[(x0 - x4) >> 14]; + blk[8 * 6] = iclp[(x3 - x2) >> 14]; + blk[8 * 7] = iclp[(x7 - x1) >> 14]; } /* two dimensional inverse discrete cosine transform */ -void gst_idct_fast_int_idct(block) -short *block; +void +gst_idct_fast_int_idct (block) + short *block; { int i; - for (i=0; i<8; i++) - idctrow(block+8*i); + for (i = 0; i < 8; i++) + idctrow (block + 8 * i); - for (i=0; i<8; i++) - idctcol(block+i); + for (i = 0; i < 8; i++) + idctcol (block + i); } -void gst_idct_init_fast_int_idct() +void +gst_idct_init_fast_int_idct () { int i; - iclp = iclip+512; - for (i= -512; i<512; i++) - iclp[i] = (i<-256) ? -256 : ((i>255) ? 255 : i); + iclp = iclip + 512; + for (i = -512; i < 512; i++) + iclp[i] = (i < -256) ? -256 : ((i > 255) ? 255 : i); } |