img_mad_16x16.h

dm642函数库

/* ======================================================================== */
/*  TEXAS INSTRUMENTS, INC.                                                 */
/*                                                                          */
/*  IMGLIB  DSP Image/Video Processing Library                              */
/*                                                                          */
/*      Release:        Revision 1.04b                                      */
/*      CVS Revision:   1.10    Sun Sep 29 03:32:24 2002 (UTC)              */
/*      Snapshot date:  23-Oct-2003                                         */
/*                                                                          */
/*  This library contains proprietary intellectual property of Texas        */
/*  Instruments, Inc.  The library and its source code are protected by     */
/*  various copyrights, and portions may also be protected by patents or    */
/*  other legal protections.                                                */
/*                                                                          */
/*  This software is licensed for use with Texas Instruments TMS320         */
/*  family DSPs.  This license was provided to you prior to installing      */
/*  the software.  You may review this license by consulting the file       */
/*  TI_license.PDF which accompanies the files in this library.             */
/* ------------------------------------------------------------------------ */
/*          Copyright (C) 2003 Texas Instruments, Incorporated.             */
/*                          All Rights Reserved.                            */
/* ======================================================================== */
/* ======================================================================== */
/*  Assembler compatibility shim for assembling 4.30 and later code on      */
/*  tools prior to 4.30.                                                    */
/* ======================================================================== */
/* ======================================================================== */
/*  End of assembler compatibility shim.                                    */
/* ======================================================================== */
/* ======================================================================== */
/*                                                                          */
/*  TEXAS INSTRUMENTS, INC.                                                 */
/*                                                                          */
/*  NAME                                                                    */
/*      IMG_mad_16x16                                                       */
/*                                                                          */
/*  REVISION DATE                                                           */
/*      18-Dec-2001                                                         */
/*                                                                          */
/*  USAGE                                                                   */
/*      This routine is C-callable and can be called as:                    */
/*                                                                          */
/*      void IMG_mad_16x16                                                  */
/*      (                                                                   */
/*          const unsigned char *restrict refImg,                           */
/*          const unsigned char *restrict srcImg,                           */
/*          int pitch,                                                      */
/*          int                 h,                                          */
/*          int                 v,                                          */
/*          unsigned            *restrict match                             */
/*      )                                                                   */
/*                                                                          */
/*      refImg          Reference image.                                    */
/*      srcImg[256]     16x16 block image to look for.                      */
/*      pitch           Width of reference image.                           */
/*      h               Horiz. size of search area.                         */
/*      v               Vert.  size of search area. Must be multiple of 2.  */
/*      match[2]        Result:                                             */
/*                          match[0] is packed x, y.                        */
/*                          match[1] is MAD value.                          */
/*                                                                          */
/*  DESCRIPTION                                                             */
/*      This routine returns the location of the minimum absolute           */
/*      difference between a 16x16 search block and some block in a         */
/*      (h + 16) x (v + 16) search area. h and v are the sizes of the       */
/*      search space for the top left coordinate of the search block.       */
/*      refImg points to the top left pixel of the search area.             */
/*                                                                          */
/*           (0,0)          (h,0)      (h+16,0)                             */
/*             ;--------------+--------;                                    */
/*             ;    search    |        ;                                    */
/*             ;    space     |        ;                                    */
/*             ;              |        ;        search area                 */
/*             ;--------------+        ;        within reference image      */
/*           (0,v)          (h,v)      ;                                    */
/*             ;                       ;                                    */
/*             ;-----------------------;                                    */
/*           (0, v+16)                 (v+16,h+16)                          */
/*                                                                          */
/*      The location is returned relative to the above coordinate system    */
/*      as x and y packed in two 16-bit quantities in a 32-bit word:        */
/*                                                                          */
/*                  31             16 15             0                      */
/*                  +----------------+----------------+                     */
/*       match[0]:  |       x        |       y        |                     */
/*                  +----------------+----------------+                     */
/*                                                                          */
/*                  31                               0                      */
/*                  +---------------------------------+                     */
/*       match[1]:  |   SAD value at location x, y    |                     */
/*                  +---------------------------------+                     */
/*                                                                          */
/*  ASSUMPTIONS                                                             */
/*      srcImg and refImg do not alias in memory.                           */
/*      The routine is written for Little Endian configuration.             */
/*      Two MADS are performed together and hence it is assumed that v      */
/*      the vertical dimension is a multiple of 2.                          */
/*                                                                          */
/*  MEMORY NOTE                                                             */
/*      No special requirements on alignment of arrays is required.         */
/*                                                                          */
/*  TECHNIQUES                                                              */
/*      The two outer loops are merged, the two inner loops are merged.     */
/*      The inner loop process 2 lines of 2 search locations in parallel.   */
/*      The search is performed in top-to-bottom, left-to-right order,      */
/*      with the earliest match taking precedence in the case of ties.      */
/*      Further use is made of C64x specific instructions such as SUBABS4   */
/*      and DOTPU4. The SUBABS4 takes the absolute difference on four 8     */
/*      bit quantities packed into a 32 bit word. The DOTPU4 performs four  */
/*      8 bit wide multiplies and adds the results together.                */
/*                                                                          */
/*  C CODE                                                                  */
/*                                                                          */
/*      void IMG_mad_16x16                                                  */
/*      (                                                                   */
/*          const unsigned char *restrict refImg,                           */
/*          const unsigned char *restrict srcImg,                           */
/*          int pitch, int h, int v,                                        */
/*          unsigned int *restrict match                                    */
/*      )                                                                   */
/*      {                                                                   */
/*          int i, j, x, y, matx, maty;                                     */
/*          unsigned matpos, matval;                                        */
/*                                                                          */
/*          matval = ~0U;                                                   */
/*          matx   = maty = 0;                                              */
/*                                                                          */
/*          for (x = 0; x < x; x++)                                         */
/*              for (y = 0; y < v; y++)                                     */
/*              {                                                           */
/*                  unsigned acc = 0;                                       */
/*                                                                          */
/*                  for (i = 0; i < 16; i++)                                */
/*                      for (j = 0; j < 16; j++)                            */
/*                          acc += abs(srcImg[i*16 + j] -                   */
/*                                     refImg[(i+y)*pitch + x + j]);        */
/*                                                                          */
/*                  if (acc < matval)                                       */
/*                  {                                                       */
/*                      matval = acc;                                       */
/*                      matx   = x;                                         */
/*                      maty   = y;                                         */
/*                  }                                                       */
/*              }                                                           */
/*                                                                          */
/*          matpos    = (0xffff0000 & (matx << 16)) |                       */
/*                      (0x0000ffff & maty);                                */
/*          match[0] = matpos;                                              */
/*          match[1] = matval;                                              */
/*      }                                                                   */
/*                                                                          */
/*  CYCLES                                                                  */
/*      38 * h * v + 20                                                     */
/*                                                                          */
/*      e.g. h=v= 4:   628 cycles                                           */
/*           h=v=32: 38932 cycles                                           */
/*                                                                          */
/*  CODESIZE                                                                */
/*      776 bytes.                                                          */
/*                                                                          */
/* ------------------------------------------------------------------------ */
/*            Copyright (c) 2003 Texas Instruments, Incorporated.           */
/*                           All Rights Reserved.                           */
/* ======================================================================== */
#ifndef IMG_MAD_16X16_H_
#define IMG_MAD_16X16_H_ 1

void IMG_mad_16x16
(
    const unsigned char *restrict refImg,
    const unsigned char *restrict srcImg,
    int pitch,
    int                 h,
    int                 v,
    unsigned            *restrict match
);

#endif
/* ======================================================================== */
/*  End of file:  img_mad_16x16.h                                           */
/* ------------------------------------------------------------------------ */
/*            Copyright (c) 2003 Texas Instruments, Incorporated.           */
/*                           All Rights Reserved.                           */
/* ======================================================================== */