EEPW论坛

x264_frame_init_lowres( h->param.cpu, fenc );

{
// FIXME: tapfilter?
const int i_stride = frame->i_stride[0];
const int i_stride2 = frame->i_stride_lowres;
const int i_width2 = i_stride2 - 64;
int x, y, i;
for( y = 0; y < frame->i_lines_lowres - 1; y++ )
{
uint8_t *src0 = &frame->plane[0][2*y*i_stride];
uint8_t *src1 = src0+i_stride;
uint8_t *src2 = src1+i_stride;
uint8_t *dst0 = &frame->lowres[0][y*i_stride2];
uint8_t *dsth = &frame->lowres[1][y*i_stride2];
uint8_t *dstv = &frame->lowres[2][y*i_stride2];
uint8_t *dstc = &frame->lowres[3][y*i_stride2];
for( x = 0; x < i_width2 - 1; x++ )
{
dst0[x] = (src0[2*x ] + src0[2*x+1] + src1[2*x ] + src1[2*x+1] + 2) >> 2;
dsth[x] = (src0[2*x+1] + src0[2*x+2] + src1[2*x+1] + src1[2*x+2] + 2) >> 2;
dstv[x] = (src1[2*x ] + src1[2*x+1] + src2[2*x ] + src2[2*x+1] + 2) >> 2;
dstc[x] = (src1[2*x+1] + src1[2*x+2] + src2[2*x+1] + src2[2*x+2] + 2) >> 2;
}
dst0[x] = (src0[2*x ] + src0[2*x+1] + src1[2*x ] + src1[2*x+1] + 2) >> 2;
dstv[x] = (src1[2*x ] + src1[2*x+1] + src2[2*x ] + src2[2*x+1] + 2) >> 2;
dsth[x] = (src0[2*x+1] + src1[2*x+1] + 1) >> 1;
dstc[x] = (src1[2*x+1] + src2[2*x+1] + 1) >> 1;
}
for( i = 0; i < 4; i++ )
memcpy( &frame->lowres[i][y*i_stride2], &frame->lowres[i][(y-1)*i_stride2], i_width2 );

for( y = 0; y < 16; y++ )
for( x = 0; x < 16; x++ )
frame->i_cost_est[x][y] = -1;

x264_frame_expand_border_lowres( frame );
}
这其中到底是一个什么构成呀，感觉怎么只有四抽头呀？还有其中的名称也不太明白const int i_stride = frame->i_stride[0];
const int i_stride2 = frame->i_stride_lowres;
const int i_width2 = i_stride2 - 64;