Initial import from the monolithic Qt.

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Branched from the monolithic repo, Qt master branch, at commit
896db169ea224deb96c59ce8af800d019de63f12

1 files changed, 978 insertions, 0 deletions

diff --git a/src/3rdparty/libmng/libmng_filter.c b/src/3rdparty/libmng/libmng_filter.c
new file mode 100644
index 0000000000..ed69a75340
--- /dev/null
+++ b/src/3rdparty/libmng/libmng_filter.c
@@ -0,0 +1,978 @@
+/* ************************************************************************** */
+/* *             For conditions of distribution and use,                    * */
+/* *                see copyright notice in libmng.h                        * */
+/* ************************************************************************** */
+/* *                                                                        * */
+/* * project   : libmng                                                     * */
+/* * file      : libmng_filter.c           copyright (c) 2000-2004 G.Juyn   * */
+/* * version   : 1.0.9                                                      * */
+/* *                                                                        * */
+/* * purpose   : Filtering routines (implementation)                        * */
+/* *                                                                        * */
+/* * author    : G.Juyn                                                     * */
+/* *                                                                        * */
+/* * comment   : implementation of the filtering routines                   * */
+/* *                                                                        * */
+/* * changes   : 0.5.1 - 05/08/2000 - G.Juyn                                * */
+/* *             - changed strict-ANSI stuff                                * */
+/* *             0.5.1 - 05/12/2000 - G.Juyn                                * */
+/* *             - changed trace to macro for callback error-reporting      * */
+/* *                                                                        * */
+/* *             0.9.2 - 08/05/2000 - G.Juyn                                * */
+/* *             - changed file-prefixes                                    * */
+/* *                                                                        * */
+/* *             0.9.3 - 09/07/2000 - G.Juyn                                * */
+/* *             - added support for new filter_types                       * */
+/* *                                                                        * */
+/* *             1.0.5 - 08/07/2002 - G.Juyn                                * */
+/* *             - added test-option for PNG filter method 193 (=no filter) * */
+/* *             1.0.5 - 08/19/2002 - G.Juyn                                * */
+/* *             - B597134 - libmng pollutes the linker namespace           * */
+/* *                                                                        * */
+/* *             1.0.6 - 07/07/2003 - G.R-P                                 * */
+/* *             - reversed some loops to use decrementing counter          * */
+/* *                                                                        * */
+/* *             1.0.9 - 12/20/2004 - G.Juyn                                * */
+/* *             - cleaned up macro-invocations (thanks to D. Airlie)       * */
+/* *                                                                        * */
+/* ************************************************************************** */
+
+#include "libmng.h"
+#include "libmng_data.h"
+#include "libmng_error.h"
+#include "libmng_trace.h"
+#ifdef __BORLANDC__
+#pragma hdrstop
+#endif
+#include "libmng_filter.h"
+
+#if defined(__BORLANDC__) && defined(MNG_STRICT_ANSI)
+#pragma option -A                      /* force ANSI-C */
+#endif
+
+/* ************************************************************************** */
+
+#ifdef MNG_INCLUDE_FILTERS
+
+/* ************************************************************************** */
+
+MNG_LOCAL mng_retcode filter_sub (mng_datap pData)
+{
+  mng_uint32 iBpp;
+  mng_uint8p pRawx;
+  mng_uint8p pRawx_prev;
+  mng_int32  iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_FILTER_SUB, MNG_LC_START);
+#endif
+
+  iBpp       = pData->iFilterbpp;
+  pRawx      = pData->pWorkrow + pData->iPixelofs + iBpp;
+  pRawx_prev = pData->pWorkrow + pData->iPixelofs;
+
+  for (iX = iBpp; iX < pData->iRowsize; iX++)
+  {
+    *pRawx = (mng_uint8)(*pRawx + *pRawx_prev);
+    pRawx++;
+    pRawx_prev++;
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_FILTER_SUB, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+MNG_LOCAL mng_retcode filter_up (mng_datap pData)
+{
+  mng_uint8p pRawx;
+  mng_uint8p pPriorx;
+  mng_int32  iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_FILTER_UP, MNG_LC_START);
+#endif
+
+  pRawx   = pData->pWorkrow + pData->iPixelofs;
+  pPriorx = pData->pPrevrow + pData->iPixelofs;
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = pData->iRowsize - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < pData->iRowsize; iX++)
+#endif
+  {
+    *pRawx = (mng_uint8)(*pRawx + *pPriorx);
+    pRawx++;
+    pPriorx++;
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_FILTER_UP, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+MNG_LOCAL mng_retcode filter_average (mng_datap pData)
+{
+  mng_int32  iBpp;
+  mng_uint8p pRawx;
+  mng_uint8p pRawx_prev;
+  mng_uint8p pPriorx;
+  mng_int32  iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_FILTER_AVERAGE, MNG_LC_START);
+#endif
+
+  iBpp       = pData->iFilterbpp;
+  pRawx      = pData->pWorkrow + pData->iPixelofs;
+  pPriorx    = pData->pPrevrow + pData->iPixelofs;
+  pRawx_prev = pData->pWorkrow + pData->iPixelofs;
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = iBpp - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < iBpp; iX++)
+#endif
+  {
+    *pRawx = (mng_uint8)(*pRawx + ((*pPriorx) >> 1));
+    pRawx++;
+    pPriorx++;
+  }
+
+  for (iX = iBpp; iX < pData->iRowsize; iX++)
+  {
+    *pRawx = (mng_uint8)(*pRawx + ((*pRawx_prev + *pPriorx) >> 1));
+    pRawx++;
+    pPriorx++;
+    pRawx_prev++;
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_FILTER_AVERAGE, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+MNG_LOCAL mng_retcode filter_paeth (mng_datap pData)
+{
+  mng_int32  iBpp;
+  mng_uint8p pRawx;
+  mng_uint8p pRawx_prev;
+  mng_uint8p pPriorx;
+  mng_uint8p pPriorx_prev;
+  mng_int32  iX;
+  mng_uint32 iA, iB, iC;
+  mng_uint32 iP;
+  mng_uint32 iPa, iPb, iPc;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_FILTER_PAETH, MNG_LC_START);
+#endif
+
+  iBpp         = pData->iFilterbpp;
+  pRawx        = pData->pWorkrow + pData->iPixelofs;
+  pPriorx      = pData->pPrevrow + pData->iPixelofs;
+  pRawx_prev   = pData->pWorkrow + pData->iPixelofs;
+  pPriorx_prev = pData->pPrevrow + pData->iPixelofs;
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = iBpp - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < iBpp; iX++)
+#endif
+  {
+    *pRawx = (mng_uint8)(*pRawx + *pPriorx);
+
+    pRawx++;
+    pPriorx++;
+  }
+
+  for (iX = iBpp; iX < pData->iRowsize; iX++)
+  {
+    iA  = (mng_uint32)*pRawx_prev;
+    iB  = (mng_uint32)*pPriorx;
+    iC  = (mng_uint32)*pPriorx_prev;
+    iP  = iA + iB - iC;
+    iPa = abs (iP - iA);
+    iPb = abs (iP - iB);
+    iPc = abs (iP - iC);
+
+    if ((iPa <= iPb) && (iPa <= iPc))
+      *pRawx = (mng_uint8)(*pRawx + iA);
+    else
+      if (iPb <= iPc)
+        *pRawx = (mng_uint8)(*pRawx + iB);
+      else
+        *pRawx = (mng_uint8)(*pRawx + iC);
+
+    pRawx++;
+    pPriorx++;
+    pRawx_prev++;
+    pPriorx_prev++;
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_FILTER_PAETH, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_filter_a_row (mng_datap pData)
+{
+  mng_retcode iRetcode;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_FILTER_A_ROW, MNG_LC_START);
+#endif
+
+  switch (*(pData->pWorkrow + pData->iFilterofs))
+  {
+    case 1  : {
+                iRetcode = filter_sub     (pData);
+                break;
+              }
+    case 2  : {
+                iRetcode = filter_up      (pData);
+                break;
+              }
+    case 3  : {
+                iRetcode = filter_average (pData);
+                break;
+              }
+    case 4  : {
+                iRetcode = filter_paeth   (pData);
+                break;
+              }
+
+    default : iRetcode = MNG_INVALIDFILTER;
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_FILTER_A_ROW, MNG_LC_END);
+#endif
+
+  return iRetcode;
+}
+
+/* ************************************************************************** */
+/* ************************************************************************** */
+
+#ifdef FILTER192
+mng_retcode mng_init_rowdiffering (mng_datap pData)
+{
+  mng_uint8p pRawi, pRawo;
+  mng_int32  iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_INIT_ROWDIFFERING, MNG_LC_START);
+#endif
+
+  if (pData->iFilter == 0xC0)          /* has leveling parameters ? */
+  {
+    switch (pData->iColortype)         /* salvage leveling parameters */
+    {
+      case 0 : {                       /* gray */
+                 if (pData->iBitdepth <= 8)
+                   pData->iLevel0 = (mng_uint16)*pData->pWorkrow;
+                 else
+                   pData->iLevel0 = mng_get_uint16 (pData->pWorkrow);
+
+                 break;
+               }
+      case 2 : {                       /* rgb */
+                 if (pData->iBitdepth <= 8)
+                 {
+                   pData->iLevel0 = (mng_uint16)*pData->pWorkrow;
+                   pData->iLevel1 = (mng_uint16)*(pData->pWorkrow+1);
+                   pData->iLevel2 = (mng_uint16)*(pData->pWorkrow+2);
+                 }
+                 else
+                 {
+                   pData->iLevel0 = mng_get_uint16 (pData->pWorkrow);
+                   pData->iLevel1 = mng_get_uint16 (pData->pWorkrow+2);
+                   pData->iLevel2 = mng_get_uint16 (pData->pWorkrow+4);
+                 }
+
+                 break;
+               }
+      case 3 : {                       /* indexed */
+                 pData->iLevel0 = (mng_uint16)*pData->pWorkrow;
+                 break;
+               }
+      case 4 : {                       /* gray+alpha */
+                 if (pData->iBitdepth <= 8)
+                 {
+                   pData->iLevel0 = (mng_uint16)*pData->pWorkrow;
+                   pData->iLevel1 = (mng_uint16)*(pData->pWorkrow+1);
+                 }
+                 else
+                 {
+                   pData->iLevel0 = mng_get_uint16 (pData->pWorkrow);
+                   pData->iLevel1 = mng_get_uint16 (pData->pWorkrow+2);
+                 }
+
+                 break;
+               }
+      case 6 : {                       /* rgb+alpha */
+                 if (pData->iBitdepth <= 8)
+                 {
+                   pData->iLevel0 = (mng_uint16)*pData->pWorkrow;
+                   pData->iLevel1 = (mng_uint16)*(pData->pWorkrow+1);
+                   pData->iLevel2 = (mng_uint16)*(pData->pWorkrow+2);
+                   pData->iLevel3 = (mng_uint16)*(pData->pWorkrow+3);
+                 }
+                 else
+                 {
+                   pData->iLevel0 = mng_get_uint16 (pData->pWorkrow);
+                   pData->iLevel1 = mng_get_uint16 (pData->pWorkrow+2);
+                   pData->iLevel2 = mng_get_uint16 (pData->pWorkrow+4);
+                   pData->iLevel3 = mng_get_uint16 (pData->pWorkrow+6);
+                 }
+
+                 break;
+               }
+    }
+  }
+                                       /* shift the entire row back in place */
+  pRawi = pData->pWorkrow + pData->iFilterofs;
+  pRawo = pData->pWorkrow;
+
+  for (iX = 0; iX < pData->iRowsize + pData->iPixelofs - pData->iFilterofs; iX++)
+    *pRawo++ = *pRawi++;
+
+  pData->iFilterofs = 0;               /* indicate so ! */
+
+#ifdef FILTER193
+  if (pData->iFilter == 0xC1)          /* no adaptive filtering ? */
+    pData->iPixelofs = pData->iFilterofs;
+  else
+#endif
+    pData->iPixelofs = pData->iFilterofs + 1;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_INIT_ROWDIFFERING, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_g1 (mng_datap pData)
+{
+  mng_uint8p pRawi, pRawo;
+  mng_int32  iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_G1, MNG_LC_START);
+#endif
+
+  if (pData->iLevel0 & 0x01)           /* is it uneven level ? */
+  {
+    pRawi = pData->pWorkrow + pData->iPixelofs;
+    pRawo = pData->pPrevrow + pData->iPixelofs;
+                                       /* just invert every bit */
+#ifdef MNG_DECREMENT_LOOPS
+    for (iX = pData->iRowsize - 1; iX >= 0; iX--)
+#else
+    for (iX = 0; iX < pData->iRowsize; iX++)
+#endif
+      *pRawo++ = (mng_uint8)(~(*pRawi++));
+
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_G1, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_g2 (mng_datap pData)
+{
+  mng_uint8p pRawi, pRawo;
+  mng_int32  iX;
+  mng_int32  iC, iS;
+  mng_uint8  iB, iN, iQ;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_G2, MNG_LC_START);
+#endif
+
+  pRawi = pData->pWorkrow + pData->iPixelofs;
+  pRawo = pData->pPrevrow + pData->iPixelofs;
+  iC    = 0;
+  iB    = 0;
+  iN    = 0;
+  iS    = 0;
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = pData->iRowsamples - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < pData->iRowsamples; iX++)
+#endif
+  {
+    if (!iC)
+    {
+      iC = 4;
+      iB = *pRawi++;
+      iN = 0;
+      iS = 8;
+    }
+
+    iS -= 2;
+    iQ = (mng_uint8)(((iB >> iS) + pData->iLevel0) & 0x03);
+    iN = (mng_uint8)((iN << 2) + iQ);
+    iC--;
+
+    if (!iC)
+      *pRawo++ = iN;
+
+  }
+
+  if (iC)
+    *pRawo = (mng_uint8)(iN << iS);
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_G2, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_g4 (mng_datap pData)
+{
+  mng_uint8p pRawi, pRawo;
+  mng_int32  iX;
+  mng_int32  iC, iS;
+  mng_uint8  iB, iN, iQ;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_G4, MNG_LC_START);
+#endif
+
+  pRawi = pData->pWorkrow + pData->iPixelofs;
+  pRawo = pData->pPrevrow + pData->iPixelofs;
+  iC    = 0;
+  iB    = 0;
+  iN    = 0;
+  iS    = 0;
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = pData->iRowsamples - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < pData->iRowsamples; iX++)
+#endif
+  {
+    if (!iC)
+    {
+      iC = 2;
+      iB = *pRawi++;
+      iN = 0;
+      iS = 8;
+    }
+
+    iS -= 4;
+    iQ = (mng_uint8)(((iB >> iS) + pData->iLevel0) & 0x0F);
+    iN = (mng_uint8)((iN << 4) + iQ);
+    iC--;
+
+    if (!iC)
+      *pRawo++ = iN;
+
+  }
+
+  if (iC)
+    *pRawo = (mng_uint8)(iN << iS);
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_G4, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_g8 (mng_datap pData)
+{
+  mng_uint8p pRawi, pRawo;
+  mng_int32  iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_G8, MNG_LC_START);
+#endif
+
+  pRawi = pData->pWorkrow + pData->iPixelofs;
+  pRawo = pData->pPrevrow + pData->iPixelofs;
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = pData->iRowsamples - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < pData->iRowsamples; iX++)
+#endif
+  {
+    *pRawo++ = (mng_uint8)(((mng_uint16)*pRawi + pData->iLevel0) & 0xFF);
+
+    pRawi++;
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_G8, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_g16 (mng_datap pData)
+{
+  mng_uint16p pRawi, pRawo;
+  mng_int32   iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_G16, MNG_LC_START);
+#endif
+
+  pRawi = (mng_uint16p)(pData->pWorkrow + pData->iPixelofs);
+  pRawo = (mng_uint16p)(pData->pPrevrow + pData->iPixelofs);
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = pData->iRowsamples - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < pData->iRowsamples; iX++)
+#endif
+  {
+    *pRawo++ = (mng_uint16)(((mng_uint32)*pRawi + (mng_uint32)pData->iLevel0) & 0xFFFF);
+
+    pRawi++;
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_G16, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_rgb8 (mng_datap pData)
+{
+  mng_uint8p pRawi, pRawo;
+  mng_int32  iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_RGB8, MNG_LC_START);
+#endif
+
+  pRawi = pData->pWorkrow + pData->iPixelofs;
+  pRawo = pData->pPrevrow + pData->iPixelofs;
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = pData->iRowsamples - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < pData->iRowsamples; iX++)
+#endif
+  {
+    *(pRawo+1) = (mng_uint8)(((mng_uint16)*(pRawi+1) + pData->iLevel1) & 0xFF);
+    *pRawo     = (mng_uint8)(((mng_uint16)*pRawi     + pData->iLevel0 +
+                              (mng_uint16)*(pRawo+1)) & 0xFF);
+    *(pRawo+2) = (mng_uint8)(((mng_uint16)*(pRawi+2) + pData->iLevel2 +
+                              (mng_uint16)*(pRawo+1)) & 0xFF);
+
+    pRawi += 3;
+    pRawo += 3;
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_RGB8, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_rgb16 (mng_datap pData)
+{
+  mng_uint16p pRawi, pRawo;
+  mng_int32   iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_RGB16, MNG_LC_START);
+#endif
+
+  pRawi = (mng_uint16p)(pData->pWorkrow + pData->iPixelofs);
+  pRawo = (mng_uint16p)(pData->pPrevrow + pData->iPixelofs);
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = pData->iRowsamples - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < pData->iRowsamples; iX++)
+#endif
+  {
+    *(pRawo+1) = (mng_uint16)(((mng_uint32)*(pRawi+1) + (mng_uint32)pData->iLevel1) & 0xFFFF);
+    *pRawo     = (mng_uint16)(((mng_uint32)*pRawi     + (mng_uint32)pData->iLevel0 +
+                               (mng_uint32)*(pRawo+1)) & 0xFFFF);
+    *(pRawo+2) = (mng_uint16)(((mng_uint32)*(pRawi+2) + (mng_uint32)pData->iLevel2 +
+                               (mng_uint32)*(pRawo+1)) & 0xFFFF);
+
+    pRawi += 3;
+    pRawo += 3;
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_RGB16, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_idx1 (mng_datap pData)
+{
+  mng_uint8p pRawi, pRawo;
+  mng_int32  iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_IDX1, MNG_LC_START);
+#endif
+
+  if (pData->iLevel0 & 0x01)           /* is it uneven level ? */
+  {
+    pRawi = pData->pWorkrow + pData->iPixelofs;
+    pRawo = pData->pPrevrow + pData->iPixelofs;
+                                       /* just invert every bit */
+#ifdef MNG_DECREMENT_LOOPS
+    for (iX = pData->iRowsize - 1; iX >= 0; iX--)
+#else
+    for (iX = 0; iX < pData->iRowsize; iX++)
+#endif
+      *pRawo++ = (mng_uint8)(~(*pRawi++));
+
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_IDX1, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_idx2 (mng_datap pData)
+{
+  mng_uint8p pRawi, pRawo;
+  mng_int32  iX;
+  mng_int32  iC, iS;
+  mng_uint8  iB, iN, iQ;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_IDX2, MNG_LC_START);
+#endif
+
+  pRawi = pData->pWorkrow + pData->iPixelofs;
+  pRawo = pData->pPrevrow + pData->iPixelofs;
+  iC    = 0;
+  iB    = 0;
+  iN    = 0;
+  iS    = 0;
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = pData->iRowsamples - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < pData->iRowsamples; iX++)
+#endif
+  {
+    if (!iC)
+    {
+      iC = 4;
+      iB = *pRawi++;
+      iN = 0;
+      iS = 8;
+    }
+
+    iS -= 2;
+    iQ = (mng_uint8)(((iB >> iS) + pData->iLevel0) & 0x03);
+    iN = (mng_uint8)((iN << 2) + iQ);
+    iC--;
+
+    if (!iC)
+      *pRawo++ = iN;
+
+  }
+
+  if (iC)
+    *pRawo = (mng_uint8)(iN << iS);
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_IDX2, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_idx4 (mng_datap pData)
+{
+  mng_uint8p pRawi, pRawo;
+  mng_int32  iX;
+  mng_int32  iC, iS;
+  mng_uint8  iB, iN, iQ;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_IDX4, MNG_LC_START);
+#endif
+
+  pRawi = pData->pWorkrow + pData->iPixelofs;
+  pRawo = pData->pPrevrow + pData->iPixelofs;
+  iC    = 0;
+  iB    = 0;
+  iN    = 0;
+  iS    = 0;
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = pData->iRowsamples - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < pData->iRowsamples; iX++)
+#endif
+  {
+    if (!iC)
+    {
+      iC = 2;
+      iB = *pRawi++;
+      iN = 0;
+      iS = 8;
+    }
+
+    iS -= 4;
+    iQ = (mng_uint8)(((iB >> iS) + pData->iLevel0) & 0x0F);
+    iN = (mng_uint8)((iN << 4) + iQ);
+    iC--;
+
+    if (!iC)
+      *pRawo++ = iN;
+
+  }
+
+  if (iC)
+    *pRawo = (mng_uint8)(iN << iS);
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_IDX4, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_idx8 (mng_datap pData)
+{
+  mng_uint8p pRawi, pRawo;
+  mng_int32  iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_IDX8, MNG_LC_START);
+#endif
+
+  pRawi = pData->pWorkrow + pData->iPixelofs;
+  pRawo = pData->pPrevrow + pData->iPixelofs;
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = pData->iRowsamples - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < pData->iRowsamples; iX++)
+#endif
+  {
+    *pRawo++ = (mng_uint8)(((mng_uint16)*pRawi + pData->iLevel0) & 0xFF);
+
+    pRawi++;
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_IDX8, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_ga8 (mng_datap pData)
+{
+  mng_uint8p pRawi, pRawo;
+  mng_int32  iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_GA8, MNG_LC_START);
+#endif
+
+  pRawi = pData->pWorkrow + pData->iPixelofs;
+  pRawo = pData->pPrevrow + pData->iPixelofs;
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = pData->iRowsamples - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < pData->iRowsamples; iX++)
+#endif
+  {
+    *pRawo     = (mng_uint8)(((mng_uint16)*pRawi     + pData->iLevel0) & 0xFF);
+    *(pRawo+1) = (mng_uint8)(((mng_uint16)*(pRawi+1) + pData->iLevel1) & 0xFF);
+
+    pRawi += 2;
+    pRawo += 2;
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_GA8, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_ga16 (mng_datap pData)
+{
+  mng_uint16p pRawi, pRawo;
+  mng_int32   iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_GA16, MNG_LC_START);
+#endif
+
+  pRawi = (mng_uint16p)(pData->pWorkrow + pData->iPixelofs);
+  pRawo = (mng_uint16p)(pData->pPrevrow + pData->iPixelofs);
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = pData->iRowsamples - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < pData->iRowsamples; iX++)
+#endif
+  {
+    *pRawo     = (mng_uint16)(((mng_uint32)*pRawi     + (mng_uint32)pData->iLevel0) & 0xFFFF);
+    *(pRawo+1) = (mng_uint16)(((mng_uint32)*(pRawi+1) + (mng_uint32)pData->iLevel1) & 0xFFFF);
+
+    pRawi += 2;
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_GA16, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_rgba8 (mng_datap pData)
+{
+  mng_uint8p pRawi, pRawo;
+  mng_int32  iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_RGBA8, MNG_LC_START);
+#endif
+
+  pRawi = pData->pWorkrow + pData->iPixelofs;
+  pRawo = pData->pPrevrow + pData->iPixelofs;
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = pData->iRowsamples - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < pData->iRowsamples; iX++)
+#endif
+  {
+    *(pRawo+1) = (mng_uint8)(((mng_uint16)*(pRawi+1) + pData->iLevel1) & 0xFF);
+    *pRawo     = (mng_uint8)(((mng_uint16)*pRawi     + pData->iLevel0 +
+                              (mng_uint16)*(pRawo+1)) & 0xFF);
+    *(pRawo+2) = (mng_uint8)(((mng_uint16)*(pRawi+2) + pData->iLevel2 +
+                              (mng_uint16)*(pRawo+1)) & 0xFF);
+    *(pRawo+3) = (mng_uint8)(((mng_uint16)*(pRawi+3) + pData->iLevel3) & 0xFF);
+
+    pRawi += 4;
+    pRawo += 4;
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_RGBA8, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+mng_retcode mng_differ_rgba16 (mng_datap pData)
+{
+  mng_uint16p pRawi, pRawo;
+  mng_int32   iX;
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_RGBA16, MNG_LC_START);
+#endif
+
+  pRawi = (mng_uint16p)(pData->pWorkrow + pData->iPixelofs);
+  pRawo = (mng_uint16p)(pData->pPrevrow + pData->iPixelofs);
+
+#ifdef MNG_DECREMENT_LOOPS
+  for (iX = pData->iRowsamples - 1; iX >= 0; iX--)
+#else
+  for (iX = 0; iX < pData->iRowsamples; iX++)
+#endif
+  {
+    *(pRawo+1) = (mng_uint16)(((mng_uint32)*(pRawi+1) + (mng_uint32)pData->iLevel1) & 0xFFFF);
+    *pRawo     = (mng_uint16)(((mng_uint32)*pRawi     + (mng_uint32)pData->iLevel0 +
+                               (mng_uint32)*(pRawo+1)) & 0xFFFF);
+    *(pRawo+2) = (mng_uint16)(((mng_uint32)*(pRawi+2) + (mng_uint32)pData->iLevel2 +
+                               (mng_uint32)*(pRawo+1)) & 0xFFFF);
+    *(pRawo+3) = (mng_uint16)(((mng_uint32)*(pRawi+3) + (mng_uint32)pData->iLevel3) & 0xFFFF);
+
+    pRawi += 4;
+    pRawo += 4;
+  }
+
+#ifdef MNG_SUPPORT_TRACE
+  MNG_TRACE (pData, MNG_FN_DIFFER_RGBA16, MNG_LC_END);
+#endif
+
+  return MNG_NOERROR;
+}
+
+/* ************************************************************************** */
+
+#endif /* FILTER192 */
+
+/* ************************************************************************** */
+
+#endif /* MNG_INCLUDE_FILTERS */
+
+/* ************************************************************************** */
+/* * end of file                                                            * */
+/* ************************************************************************** */
+