/*The function used to fill in the chroma plane motion vectors for a macro
block when 4 different motion vectors are specified in the luma plane.
This version is for use with chroma decimated in the X and Y directions.
_cbmvs: The chroma block-level motion vectors to fill in.
_lbmvs: The luma block-level motion vectors.*/
static void oc_set_chroma_mvs00(oc_mv _cbmvs[4],const oc_mv _lbmvs[4]){
int dx;
int dy;
dx=_lbmvs[0][0]+_lbmvs[1][0]+_lbmvs[2][0]+_lbmvs[3][0];
dy=_lbmvs[0][1]+_lbmvs[1][1]+_lbmvs[2][1]+_lbmvs[3][1];
_cbmvs[0][0]=(signed char)OC_DIV_ROUND_POW2(dx,2,2);
_cbmvs[0][1]=(signed char)OC_DIV_ROUND_POW2(dy,2,2);
}
/*The function used to fill in the chroma plane motion vectors for a macro
block when 4 different motion vectors are specified in the luma plane.
This version is for use with chroma decimated in the X and Y directions
(4:2:0).
_cbmvs: The chroma block-level motion vectors to fill in.
_lbmvs: The luma block-level motion vectors.*/
static void oc_set_chroma_mvs00(oc_mv _cbmvs[4],const oc_mv _lbmvs[4]){
int dx;
int dy;
dx=OC_MV_X(_lbmvs[0])+OC_MV_X(_lbmvs[1])
+OC_MV_X(_lbmvs[2])+OC_MV_X(_lbmvs[3]);
dy=OC_MV_Y(_lbmvs[0])+OC_MV_Y(_lbmvs[1])
+OC_MV_Y(_lbmvs[2])+OC_MV_Y(_lbmvs[3]);
_cbmvs[0]=OC_MV(OC_DIV_ROUND_POW2(dx,2,2),OC_DIV_ROUND_POW2(dy,2,2));
}
/*Pads a single row of a partial block and then performs a forward Type-II DCT
on the result.
The output is scaled by a factor of 2 from the orthonormal version of the
transform.
_y: The buffer to store the result in.
Data will be placed in every 8th entry (e.g., in a column of an 8x8
block).
_x: The input coefficients.
The first 8 entries are used (e.g., from a row of an 8x8 block).
_e: The extension information for the shape.*/
static void fdct8_ext(ogg_int16_t *_y,ogg_int16_t _x[8],
const oc_extension_info *_e){
if(_e->na==1){
int ci;
/*While the branch below is still correct for shapes with na==1, we can
perform the entire transform with just 1 multiply in this case instead
of 23.*/
_y[0]=(ogg_int16_t)(OC_DIV2_16(OC_C4S4*(_x[_e->pi[0]]<<3)));
for(ci=8;ci<64;ci+=8)_y[ci]=0;
}
else{
int zpi;
int api;
int nz;
/*First multiply by the extension matrix to compute the padding values.*/
nz=8-_e->na;
for(zpi=0;zpi<nz;zpi++){
ogg_int32_t v;
v=0;
for(api=0;api<_e->na;api++)v+=_e->ext[zpi][api]*_x[_e->pi[api]];
_x[_e->pi[zpi+_e->na]]=
(ogg_int16_t)OC_DIV_ROUND_POW2(v,OC_EXT_SHIFT,1<<OC_EXT_SHIFT-1);
}
fdct8(_y,_x);
}
}