func: static inline int yv12toyuy2_unscaled_altivec(SwsContext *c, uint8_t* src[], int srcStride[], int srcSliceY,
  
       int srcSliceH, uint8_t* dstParam[], int dstStride_a[]) {
  
    uint8_t *dst=dstParam[0] + dstStride_a[0]*srcSliceY;
  
    // yv12toyuy2( src[0],src[1],src[2],dst,c->srcW,srcSliceH,srcStride[0],srcStride[1],dstStride[0] );
  
    uint8_t *ysrc = src[0];
  
    uint8_t *usrc = src[1];
  
    uint8_t *vsrc = src[2];
  
    const int width = c->srcW;
  
    const int height = srcSliceH;
  
    const int lumStride = srcStride[0];
  
    const int chromStride = srcStride[1];
  
    const int dstStride = dstStride_a[0];
  
    const vector unsigned char yperm = vec_lvsl(0, ysrc);
  
    const int vertLumPerChroma = 2;
  
    register unsigned int y;
  
  
  
    if(width&15){
  
      yv12toyuy2( ysrc, usrc, vsrc, dst,c->srcW,srcSliceH, lumStride, chromStride, dstStride);
  
      return srcSliceH;
  
    }
  
  
  
    /* this code assume:
  
  
  
    1) dst is 16 bytes-aligned
  
    2) dstStride is a multiple of 16
  
    3) width is a multiple of 16
  
    4) lum&chrom stride are multiple of 8
  
    */
  
  
  
    for(y=0; y<height; y++)
  
      {
  
        int i;
  
        for (i = 0; i < width - 31; i+= 32) {
  
  	const unsigned int j = i >> 1;
  
  	vector unsigned char v_yA = vec_ld(i, ysrc);
  
  	vector unsigned char v_yB = vec_ld(i + 16, ysrc);
  
  	vector unsigned char v_yC = vec_ld(i + 32, ysrc);
  
  	vector unsigned char v_y1 = vec_perm(v_yA, v_yB, yperm);
  
  	vector unsigned char v_y2 = vec_perm(v_yB, v_yC, yperm);
  
  	vector unsigned char v_uA = vec_ld(j, usrc);
  
  	vector unsigned char v_uB = vec_ld(j + 16, usrc);
  
  	vector unsigned char v_u = vec_perm(v_uA, v_uB, vec_lvsl(j, usrc));
  
  	vector unsigned char v_vA = vec_ld(j, vsrc);
  
  	vector unsigned char v_vB = vec_ld(j + 16, vsrc);
  
  	vector unsigned char v_v = vec_perm(v_vA, v_vB, vec_lvsl(j, vsrc));
  
  	vector unsigned char v_uv_a = vec_mergeh(v_u, v_v);
  
  	vector unsigned char v_uv_b = vec_mergel(v_u, v_v);
  
  	vector unsigned char v_yuy2_0 = vec_mergeh(v_y1, v_uv_a);
  
  	vector unsigned char v_yuy2_1 = vec_mergel(v_y1, v_uv_a);
  
  	vector unsigned char v_yuy2_2 = vec_mergeh(v_y2, v_uv_b);
  
  	vector unsigned char v_yuy2_3 = vec_mergel(v_y2, v_uv_b);
  
  	vec_st(v_yuy2_0, (i << 1), dst);
  
  	vec_st(v_yuy2_1, (i << 1) + 16, dst);
  
  	vec_st(v_yuy2_2, (i << 1) + 32, dst);
  
  	vec_st(v_yuy2_3, (i << 1) + 48, dst);
  
        }
  
        if (i < width) {
  
  	const unsigned int j = i >> 1;
  
  	vector unsigned char v_y1 = vec_ld(i, ysrc);
  
  	vector unsigned char v_u = vec_ld(j, usrc);
  
  	vector unsigned char v_v = vec_ld(j, vsrc);
  
  	vector unsigned char v_uv_a = vec_mergeh(v_u, v_v);
  
  	vector unsigned char v_yuy2_0 = vec_mergeh(v_y1, v_uv_a);
  
  	vector unsigned char v_yuy2_1 = vec_mergel(v_y1, v_uv_a);
  
  	vec_st(v_yuy2_0, (i << 1), dst);
  
  	vec_st(v_yuy2_1, (i << 1) + 16, dst);
  
        }
  
        if((y&(vertLumPerChroma-1))==(vertLumPerChroma-1) )
  
  	{
  
  	  usrc += chromStride;
  
  	  vsrc += chromStride;
  
  	}
  
        ysrc += lumStride;
  
        dst += dstStride;
  
      }
  
  
  
    return srcSliceH;
  
  }
  