refbuf.c

来自「压缩JM12.3d的完整的全部C语言的代码文档,用于嵌入式系统的压缩编解码」· C语言 代码 · 共 76 行

/*!
 ************************************************************************
 * \file refbuf.c
 *
 * \brief
 *    Declarations of teh reference frame buffer types and functions
 ************************************************************************
 */

#include <stdlib.h>
#include <memory.h>
#include "global.h"

#include "refbuf.h"


/*!
 ************************************************************************
 * \brief
 *    Yields a pel line _pointer_ from one of the 16 sub-images
 *    Input does not require subpixel image indices
 ************************************************************************
 */
imgpel *FastLine4X (imgpel ****Pic, int y, int x)
{
  return &(Pic[(y & 0x03)][(x & 0x03)][y >> 2][x >> 2]);
}

/*!
 ************************************************************************
 * \brief
 *    Yields a pel line _pointer_ from one of the 16 sub-images
 *    Input does not require subpixel image indices
 ************************************************************************
 */
imgpel *UMVLine4X (imgpel ****Pic, int y, int x)
{
  int xpos = iClip3( 0, width_pad , x >> 2);
  int ypos = iClip3( 0, height_pad, y >> 2);

  return &(Pic[(y & 0x03)][(x & 0x03)][ypos][xpos]);
}

/*!
 ************************************************************************
 * \brief
 *    Yields a pel line _pointer_ from one of the 16 (4:4:4), 32 (4:2:2),
 *    or 64 (4:2:0) sub-images
 *    Input does not require subpixel image indices
 ************************************************************************
 */
imgpel *UMVLine8X_chroma (imgpel ****Pic, int y, int x)
{
  int xpos  = iClip3 (0, width_pad_cr , x >> chroma_shift_x);
  int ypos  = iClip3 (0, height_pad_cr, y >> chroma_shift_y);

  return &(Pic[y & chroma_mask_mv_y][x & chroma_mask_mv_x][ypos][xpos]);
}

/*!
 ************************************************************************
 * \brief
 *    Yields a pel line _pointer_ from one of the 16 (4:4:4), 32 (4:2:2),
 *    or 64 (4:2:0) sub-images
 *    Input does not require subpixel image indices
 ************************************************************************
 */
imgpel *FastLine8X_chroma (imgpel ****Pic, int y, int x)
{
  return &(Pic[y & chroma_mask_mv_y][x & chroma_mask_mv_x][y >> chroma_shift_y][x >> chroma_shift_x]);
}