src/BlinkenFrame.c (bf06f77) - BlinkenLib · BlinkenArea

BlinkenFrame.c

/* BlinkenLib
   Copyright 2004-2014 Stefan Schuermans <stefan@schuermans.info>
   Copyleft GNU public license - http://www.gnu.org/copyleft/gpl.html
   a blinkenarea.org project */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef WIN32
#include <winsock2.h>
#include <windows.h>
typedef WORD uint16_t;
typedef DWORD uint32_t;
#else
#include <stdint.h>
#include <netinet/in.h>
#endif

#include <BlinkenLib/BlinkenColorizer.h>
#include <BlinkenLib/BlinkenFrame.h>

#include "BlinkenConstants.h"
#include "BlinkenProtoIntern.h"
#include "Tools.h"

struct sBlinkenFrame {
  int height;
  int width;
  int channels;
  int maxval;
  int duration;
  unsigned char **ppData;
};

stBlinkenFrame *BlinkenFrameNew(int height, int width, int channels,
                                int maxval, int duration)
{
  stBlinkenFrame *pFrame;

if (height < BlinkenHeightMin)
    height = BlinkenHeightMin;
  if (height > BlinkenHeightMax)
    height = BlinkenHeightMax;
  if (width < BlinkenWidthMin)
    width = BlinkenWidthMin;
  if (width > BlinkenWidthMax)
    width = BlinkenWidthMax;
  if (channels < BlinkenChannelsMin)
    channels = BlinkenChannelsMin;
  if (channels > BlinkenChannelsMax)
    channels = BlinkenMaxvalMax;
  if (maxval < BlinkenMaxvalMin)
    maxval = BlinkenMaxvalMin;
  if (maxval > BlinkenMaxvalMax)
    maxval = BlinkenMaxvalMax;
  if (duration < BlinkenDurationMin)
    duration = BlinkenDurationMin;
  if (duration > BlinkenDurationMax)
    duration = BlinkenDurationMax;

pFrame = (stBlinkenFrame *) malloc(sizeof(stBlinkenFrame));
  if (pFrame == NULL)
    return NULL;

pFrame->height = height;
  pFrame->width = width;
  pFrame->channels = channels;
  pFrame->maxval = maxval;
  pFrame->duration = duration;

pFrame->ppData =
      (unsigned char **)BlinkenMalloc2D(height, width * channels,
                                        sizeof(unsigned char));
  if (pFrame->ppData == NULL) {
    free(pFrame);
    return NULL;
  }

return pFrame;
}

stBlinkenFrame *BlinkenFrameClone(stBlinkenFrame *pSrcFrame)
{
  int y, x, c, i;
  stBlinkenFrame *pFrame;

if (pSrcFrame == NULL)
    return NULL;

pFrame = BlinkenFrameNew(pSrcFrame->height, pSrcFrame->width,
                           pSrcFrame->channels, pSrcFrame->maxval,
                           pSrcFrame->duration);
  if (pFrame == NULL)
    return NULL;

for (y = 0; y < pFrame->height; y++)
    for (x = 0, i = 0; x < pFrame->width; x++)
      for (c = 0; c < pFrame->channels; c++, i++)
        pFrame->ppData[y][i] = pSrcFrame->ppData[y][i];

return pFrame;
}

void BlinkenFrameFree(stBlinkenFrame *pFrame)
{
  if (pFrame == NULL)
    return;

free(pFrame->ppData);
  free(pFrame);
}

void BlinkenFrameClear(stBlinkenFrame *pFrame)
{
  int y, x, c, i;

if (pFrame == NULL)
    return;

for (y = 0; y < pFrame->height; y++)
    for (x = 0, i = 0; x < pFrame->width; x++)
      for (c = 0; c < pFrame->channels; c++, i++)
        pFrame->ppData[y][i] = 0;
}

int BlinkenFrameGetHeight(stBlinkenFrame *pFrame)
{
  if (pFrame == NULL)
    return 0;

return pFrame->height;
}

int BlinkenFrameGetWidth(stBlinkenFrame *pFrame)
{
  if (pFrame == NULL)
    return 0;

return pFrame->width;
}

int BlinkenFrameGetChannels(stBlinkenFrame *pFrame)
{
  if (pFrame == NULL)
    return 0;

return pFrame->channels;
}

int BlinkenFrameGetMaxval(stBlinkenFrame *pFrame)
{
  if (pFrame == NULL)
    return 0;

return pFrame->maxval;
}

int BlinkenFrameGetDuration(stBlinkenFrame *pFrame)
{
  if (pFrame == NULL)
    return 0;

return pFrame->duration;
}

void BlinkenFrameSetDuration(stBlinkenFrame *pFrame, int duration)
{
  if (pFrame == NULL)
    return;

if (duration < BlinkenDurationMin)
    duration = BlinkenDurationMin;
  if (duration > BlinkenDurationMax)
    duration = BlinkenDurationMax;

pFrame->duration = duration;
}

unsigned char BlinkenFrameGetPixel(stBlinkenFrame *pFrame, int y, int x,
                                   int c)
{
  if (pFrame == NULL ||
      y < 0 || y >= pFrame->height ||
      x < 0 || x >= pFrame->width || c < 0 || c >= pFrame->channels)
    return 0;

return pFrame->ppData[y][x * pFrame->channels + c];
}

void BlinkenFrameSetPixel(stBlinkenFrame *pFrame, int y, int x, int c,
                          unsigned char val)
{
  if (pFrame == NULL ||
      y < 0 || y >= pFrame->height ||
      x < 0 || x >= pFrame->width || c < 0 || c >= pFrame->channels)
    return;

if (val > pFrame->maxval)
    val = pFrame->maxval;
  pFrame->ppData[y][x * pFrame->channels + c] = val;
}

unsigned long BlinkenFrameGetColor(stBlinkenFrame *pFrame, int y, int x)
{
  int i;

if (pFrame == NULL ||
      y < 0 || y >= pFrame->height || x < 0 || x >= pFrame->width)
    return 0;

i = x * pFrame->channels;

if (pFrame->channels == 1)
    return (((unsigned long)pFrame->ppData[y][i + 0] * 255 +
             pFrame->maxval / 2) /
            pFrame->
            maxval) << 16 | (((unsigned long)pFrame->ppData[y][i + 0] * 255 +
                              pFrame->maxval / 2) /
                             pFrame->maxval) << 8 | (((unsigned long)
                                                      pFrame->ppData[y][i +
                                                                        0] *
                                                      255 +
                                                      pFrame->maxval / 2) /
                                                     pFrame->maxval);
  if (pFrame->channels == 2)
    return (((unsigned long)pFrame->ppData[y][i + 0] * 255 +
             pFrame->maxval / 2) /
            pFrame->
            maxval) << 16 | (((unsigned long)pFrame->ppData[y][i + 1] * 255 +
                              pFrame->maxval / 2) / pFrame->maxval) << 8;
  return (((unsigned long)pFrame->ppData[y][i + 0] * 255 +
           pFrame->maxval / 2) /
          pFrame->maxval) << 16 | (((unsigned long)pFrame->ppData[y][i + 1] *
                                    255 +
                                    pFrame->maxval / 2) /
                                   pFrame->maxval) << 8 | (((unsigned long)
                                                            pFrame->ppData[y]
                                                            [i + 2] * 255 +
                                                            pFrame->maxval /
                                                            2) /
                                                           pFrame->maxval);
}

void BlinkenFrameSetColor(stBlinkenFrame *pFrame, int y, int x,
                          unsigned long color)
{
  int i, alpha, alpha_, c;

if (pFrame == NULL ||
      y < 0 || y >= pFrame->height || x < 0 || x >= pFrame->width)
    return;

i = x * pFrame->channels;

alpha = (color >> 24) & 0xFF;
  alpha_ = 255 - alpha;
  if (pFrame->channels >= 1)
    pFrame->ppData[y][i + 0] =
        (unsigned
         char)((((((color >> 16) & 0xFF) * pFrame->maxval +
                  127) / 255) * alpha + (unsigned long)pFrame->ppData[y][i +
                                                                         0] *
                alpha_) / 255);
  if (pFrame->channels >= 2)
    pFrame->ppData[y][i + 1] =
        (unsigned
         char)((((((color >> 8) & 0xFF) * pFrame->maxval +
                  127) / 255) * alpha + (unsigned long)pFrame->ppData[y][i +
                                                                         1] *
                alpha_) / 255);
  if (pFrame->channels >= 3)
    pFrame->ppData[y][i + 2] =
        (unsigned
         char)(((((color & 0xFF) * pFrame->maxval + 127) / 255) * alpha +
                (unsigned long)pFrame->ppData[y][i + 2] * alpha_) / 255);
  for (c = 3; c < pFrame->channels; c++)
    pFrame->ppData[y][i + c] = (unsigned char)((0 + (unsigned long)
                                                pFrame->ppData[y][i +
                                                                  c] *
                                                alpha_) / 255);
}

void BlinkenFrameGetPixelData(stBlinkenFrame const *pFrame,
                              int y, int dy, int x, int dx, int c, int dc,
                              unsigned char *pData)
{
  int height, width, channels;
  unsigned char const **ppFrameData;
  int sy, ey, iy, sx, ex, ix, sc, ec, ic; // start/end/index x/y/channel
  int fy, fix, fic; // indexes into frame data
  int biy, bix, bic; // index into caller's data buffer

// no frame -> leave
  if (pFrame == NULL) {
    return;
  }

height = pFrame->height;
  width = pFrame->width;
  channels = pFrame->channels;
  ppFrameData = (unsigned char const **)pFrame->ppData;

// compute start and end for each coordinate
  sy = y < 0 ? -y : 0;
  ey = y + dy > height ? height - y : dy;
  sx = x < 0 ? -x : 0;
  ex = x + dx > width ? width - x : dx;
  sc = c < 0 ? -c : 0;
  ec = c + dc > channels ? channels - c : dc;

// get pixel data
  for (iy = sy, fy = y, biy = (sy * dx + sx) * dc + sc;
       iy < ey; ++iy, ++fy, biy += dx * dc) {
    for (ix = sx, fix = x * channels + c, bix = biy;
         ix < ex; ++ix, fix += channels, bix += dc) {
      for (ic = sc, fic = fix, bic = bix; ic < ec; ++ic, ++fic, ++bic) {
        pData[bic] = ppFrameData[fy][fic];
      }
    }
  }
}

void BlinkenFrameSetPixelData(stBlinkenFrame *pFrame,
                              int y, int dy, int x, int dx, int c, int dc,
                              unsigned char const *pData)
{
  int height, width, channels;
  unsigned char maxval;
  unsigned char **ppFrameData;
  int sy, ey, iy, sx, ex, ix, sc, ec, ic; // start/end/index x/y/channel
  int fy, fix, fic; // indexes into frame data
  int biy, bix, bic; // index into caller's data buffer
  unsigned char value;

// no frame -> leave
  if (pFrame == NULL) {
    return;
  }

height = pFrame->height;
  width = pFrame->width;
  channels = pFrame->channels;
  maxval = pFrame->maxval;
  ppFrameData = pFrame->ppData;

// set pixel data
  for (iy = sy, fy = y, biy = (sy * dx + sx) * dc + sc;
       iy < ey; ++iy, ++fy, biy += dx * dc) {
    for (ix = sx, fix = x * channels + c, bix = biy;
         ix < ex; ++ix, fix += channels, bix += dc) {
      for (ic = sc, fic = fix, bic = bix; ic < ec; ++ic, ++fic, ++bic) {
        value = pData[bic];
        ppFrameData[fy][fic] = value > maxval ? maxval : value;
      }
    }
  }
}

int BlinkenFrameIsEmpty(stBlinkenFrame *pFrame)
// returns 1 if frame is empty (i.e. black), returns 0 otherwise
{
  int y, x, c, i;

if (pFrame == NULL)
    return 0;

for (y = 0; y < pFrame->height; y++) {
    for (x = 0, i = 0; x < pFrame->width; x++) {
      for (c = 0; c < pFrame->channels; c++, i++) {
        if (pFrame->ppData[y][i] != 0)
          break;        // pixel is not black -> abort
      }
      if (c < pFrame->channels)
        break;
    }
    if (x < pFrame->width)
      break;
  }
  if (y < pFrame->height)
    return 0;   // aborted somewhere -> at least ony pixel is not black
  else
    return 1;   // not aborted -> all pixels are black
}

int BlinkenFrameCompare(stBlinkenFrame *pFrame1, stBlinkenFrame *pFrame2)
// returns -1 for frame1 smaller, 0 for equal, 1 for frame2 smaller
{
  int y, cmp;

if (pFrame1->height < pFrame2->height)
    return -1;
  if (pFrame1->height > pFrame2->height)
    return 1;
  if (pFrame1->width < pFrame2->width)
    return -1;
  if (pFrame1->width > pFrame2->width)
    return 1;
  if (pFrame1->channels < pFrame2->channels)
    return -1;
  if (pFrame1->channels > pFrame2->channels)
    return 1;
  if (pFrame1->maxval < pFrame2->maxval)
    return -1;
  if (pFrame1->maxval > pFrame2->maxval)
    return 1;

for (y = 0; y < pFrame1->height; y++) {
    cmp =
        memcmp(pFrame1->ppData[y], pFrame2->ppData[y],
               pFrame1->width * pFrame2->channels);
    if (cmp != 0)
      return cmp;
  }

return 0;
}

static void BlinkenFramePadCrop(stBlinkenFrame *pFrame, int height, int width,
                                int channels, int maxval,
                                int emptyY, int emptyX, int skipY, int skipX)
{
  unsigned char **ppData;
  int y, x, c, i, j;
  int rangeY, rangeX;
  unsigned long val, div;

if (pFrame == NULL)
    return;

if (height == pFrame->height && width == pFrame->width &&
      channels == pFrame->channels && maxval == pFrame->maxval &&
      emptyX == 0 && emptyY == 0 && skipY == 0 && skipX == 0)
    return;

// allocate new data array
  ppData = (unsigned char **)BlinkenMalloc2D(height, width * channels,
                                             sizeof(unsigned char));
  if (ppData == NULL)
    return;
  for (y = 0; y < height; y++)
    for (x = 0, i = 0; x < width; x++)
      for (c = 0; c < channels; c++, i++)
        ppData[y][i] = 0;

// sanitize number of pixels to skip / to leave empty in X and Y direction
  if (emptyY < 0)
    emptyY = 0;
  if (emptyY > height)
    emptyY = height;
  if (emptyX < 0)
    emptyX = 0;
  if (emptyX > width)
    emptyX = width;
  if (skipY < 0)
    skipY = 0;
  if (skipY > pFrame->height)
    skipY = pFrame->height;
  if (skipX < 0)
    skipX = 0;
  if (skipX > pFrame->width)
    skipX = pFrame->width;
  rangeY = mini(height - emptyY, pFrame->height - skipY);
  rangeX = mini(width - emptyX, pFrame->width - skipX);

// pad/crop frame with help of calculated parameters
  for (y = 0; y < rangeY; y++) {
    for (x = 0; x < rangeX; x++) {
      i = (skipX + x) * pFrame->channels;
      j = (emptyX + x) * channels;
      if (channels >= pFrame->channels) // add channels: copy last channel
        // into new channels
      {
        for (c = 0; c < pFrame->channels; c++, i++, j++)
          ppData[emptyY + y][j] =
              (unsigned
               char)(((unsigned long)pFrame->ppData[skipY + y][i] * maxval +
                      pFrame->maxval / 2) / pFrame->maxval);
        for (; c < channels; c++, j++)
          ppData[emptyY + y][j] = ppData[emptyY + y][j - 1];
      } else    // remove channels: merge leftover channels with last kept
        // channel
      {
        val = 0;
        for (c = 0; c < channels - 1; c++, i++, j++)
          ppData[emptyY + y][j] =
              (unsigned
               char)(((unsigned long)pFrame->ppData[skipY + y][i] * maxval +
                      pFrame->maxval / 2) / pFrame->maxval);
        for (c = channels - 1; c < pFrame->channels; c++, i++)
          val += (unsigned long)pFrame->ppData[skipY + y][i];
        div = pFrame->maxval * (pFrame->channels - channels + 1);
        ppData[emptyY + y][j++] =
            (unsigned char)((val * maxval + div / 2) / div);
      }
    }
  }

pFrame->height = height;
  pFrame->width = width;
  pFrame->channels = channels;
  pFrame->maxval = maxval;
  free(pFrame->ppData);
  pFrame->ppData = ppData;
}

void BlinkenFrameResize(stBlinkenFrame *pFrame, int height, int width,
                        int channels, int maxval)
{
  int emptyY, emptyX, skipY, skipX;

if (pFrame == NULL)
    return;

if (height == pFrame->height && width == pFrame->width &&
      channels == pFrame->channels && maxval == pFrame->maxval)
    return;

// get number of pixels to skip / to leave empty in X and Y direction
  if (height > pFrame->height) {
    emptyY = (height - pFrame->height) / 2;
    skipY = 0;
  } else {
    emptyY = 0;
    skipY = (pFrame->height - height) / 2;
  }
  if (width > pFrame->width) {
    emptyX = (width - pFrame->width) / 2;
    skipX = 0;
  } else {
    emptyX = 0;
    skipX = (pFrame->width - width) / 2;
  }

// resize frame with help of calculated parameters
  BlinkenFramePadCrop(pFrame, height, width, channels, maxval,
                      emptyY, emptyX, skipY, skipX);
}

void BlinkenFrameCrop(stBlinkenFrame *pFrame, int top, int left,
                      int height, int width)
{
  if (pFrame == NULL)
    return;

if (top < 0)
    top = 0;
  if (top > pFrame->height - BlinkenHeightMin)
    top = pFrame->height - BlinkenHeightMin;
  if (height < BlinkenHeightMin)
    height = BlinkenHeightMin;
  if (height > pFrame->height - top)
    height = pFrame->height - top;
  if (left < 0)
    left = 0;
  if (left > pFrame->width - BlinkenWidthMin)
    left = pFrame->width - BlinkenWidthMin;
  if (width < BlinkenWidthMin)
    width = BlinkenWidthMin;
  if (width > pFrame->width - left)
    width = pFrame->width - left;

if (top == 0 && left == 0 &&
      height == pFrame->height && width == pFrame->width)
    return;

// crop frame with help of calculated parameters
  BlinkenFramePadCrop(pFrame, height, width, pFrame->channels, pFrame->maxval,
                      0, 0, top, left);
}

void BlinkenFrameScale(stBlinkenFrame *pFrame, int height, int width)
{
  unsigned char **ppData;
  double scaleHor, scaleVer, ox, oy, ox1, oy1, val;
  int chans, c, nx, ny, x, y, oxi, oyi, ox1i, oy1i;

if (pFrame == NULL)
    return;

if (height == pFrame->height && width == pFrame->width)
    return;

scaleHor = (double)width / (double)pFrame->width;
  scaleVer = (double)height / (double)pFrame->height;

// allocate new data array
  ppData =
      (unsigned char **)BlinkenMalloc2D(height, width * pFrame->channels,
                                        sizeof(unsigned char));
  if (ppData == NULL)
    return;

// scale every channel
  chans = pFrame->channels;
  for (c = 0; c < chans; c++) {
    for (ny = 0; ny < height; ny++) {
      for (nx = 0; nx < width; nx++) {
        oy = (double)ny / scaleVer;     // sub-pixel exact range in old
        // picture
        ox = (double)nx / scaleHor;
        oy1 = (double)(ny + 1) / scaleVer - 0.000001;
        ox1 = (double)(nx + 1) / scaleHor - 0.000001;
        if (oy < 0 || ox < 0 || oy1 >= pFrame->height || ox1 >= pFrame->width)
          // out of old picture
          ppData[ny][nx * chans + c] = 0;
        else {
          oyi = (int)oy;
          oxi = (int)ox;
          oy1i = (int)oy1;
          ox1i = (int)ox1;
          if (oyi == oy1i) {
            if (oxi == ox1i)    // one source pixel
            {
              val = (double)pFrame->ppData[oyi][oxi * chans + c];
            } else      // one line of source pixels
            {
              val =
                  (double)pFrame->ppData[oyi][oxi * chans + c] * (1 - ox +
                                                                  oxi)
                  + (double)pFrame->ppData[oyi][ox1i * chans + c] * (ox1 -
                                                                     ox1i);
              for (x = oxi + 1; x < ox1i; x++)
                val += (double)pFrame->ppData[oyi][x * chans + c];
              val /= ox1 - ox;
            }
          } else        // one column of source pixels
          {
            if (oxi == ox1i) {
              val =
                  (double)pFrame->ppData[oyi][oxi * chans + c] * (1 - oy +
                                                                  oyi)
                  + (double)pFrame->ppData[oy1i][oxi * chans + c] * (oy1 -
                                                                     oy1i);
              for (y = oyi + 1; y < oy1i; y++)
                val += (double)pFrame->ppData[y][oxi * chans + c];
              val /= oy1 - oy;
            } else      // rectangle of source pixels
            {
              val =
                  (double)pFrame->ppData[oyi][oxi * chans + c] * (1 - oy +
                                                                  oyi) * (1 -
                                                                          ox +
                                                                          oxi)
                  + (double)pFrame->ppData[oyi][ox1i * chans + c] * (1 - oy +
                                                                     oyi) *
                  (ox1 - ox1i)
                  + (double)pFrame->ppData[oy1i][oxi * chans + c] * (oy1 -
                                                                     oy1i) *
                  (1 - ox + oxi)
                  + (double)pFrame->ppData[oy1i][ox1i * chans + c] * (oy1 -
                                                                      oy1i) *
                  (ox1 - ox1i);
              for (y = oyi + 1; y < oy1i; y++) {
                val +=
                    (double)pFrame->ppData[y][oxi * chans + c] * (1 - ox +
                                                                  oxi)
                    + (double)pFrame->ppData[y][ox1i * chans + c] * (ox1 -
                                                                     ox1i);
              }
              for (x = oxi + 1; x < ox1i; x++) {
                val +=
                    (double)pFrame->ppData[oyi][x * chans + c] * (1 - oy +
                                                                  oyi)
                    + (double)pFrame->ppData[oy1i][x * chans + c] * (oy1 -
                                                                     oy1i);
              }
              for (y = oyi + 1; y < oy1i; y++)
                for (x = oxi + 1; x < ox1i; x++)
                  val += (double)pFrame->ppData[y][x * chans + c];
              val /= (oy1 - oy) * (ox1 - ox);
            }
          }
          ppData[ny][nx * chans + c] = (unsigned char)(val + 0.5);
        }
      } // for( nx ...
    }   // for( ny ...
  }     // for( c ...

pFrame->height = height;
  pFrame->width = width;
  free(pFrame->ppData);
  pFrame->ppData = ppData;
}

void BlinkenFrameColorize(stBlinkenFrame *pFrame, int channels, int mode,
                          int step)
{
  unsigned char **ppData;
  int y, x, c, i, j;
  unsigned int val;

if (pFrame == NULL)
    return;

if (channels < BlinkenChannelsMin)
    channels = BlinkenChannelsMin;
  if (channels > BlinkenChannelsMax)
    channels = BlinkenMaxvalMax;

// allocate new data array
  ppData =
      (unsigned char **)BlinkenMalloc2D(pFrame->height,
                                        pFrame->width * channels,
                                        sizeof(unsigned char));
  if (ppData == NULL)
    return;
  for (y = 0; y < pFrame->height; y++)
    for (x = 0, i = 0; x < pFrame->width; x++)
      for (c = 0; c < channels; c++, i++)
        ppData[y][i] = 0;

// colorize frame
  for (y = 0; y < pFrame->height; y++) {
    for (x = 0; x < pFrame->width; x++) {
      i = x * pFrame->channels;
      // merge channels
      val = 0;
      for (c = 0; c < pFrame->channels; c++, i++)
        val += pFrame->ppData[y][i];
      val = (val + pFrame->channels / 2) / pFrame->channels;
      val = (val * BlinkenMaxvalMax + pFrame->maxval / 2) / pFrame->maxval;
      // colorize
      j = x * channels;
      for (c = 0; c < channels; c++, j++) {
        int color = BlinkenColorizerGetColor(channels, mode, step, y, x, c);
        ppData[y][j] = (unsigned char)((val * color + 127) / 255);
      }
    }
  }

pFrame->channels = channels;
  pFrame->maxval = BlinkenMaxvalMax;
  free(pFrame->ppData);
  pFrame->ppData = ppData;
}

void BlinkenFrameCopyRect(stBlinkenFrame *pDest, int destY, int destX,
                          stBlinkenFrame *pSrc, int srcY, int srcX,
                          int height, int width)
{
  int bFreeSrc = 0;
  int destI, srcI, y, x, c, dy, sy, di, si;

if (pDest == NULL || pSrc == NULL)
    return;

// make sure source frame matches dest frame in channels and maxval
  if (pSrc->channels != pDest->channels || pSrc->maxval != pDest->maxval) {
    pSrc = BlinkenFrameClone(pSrc);
    if (pSrc == NULL)
      return;
    BlinkenFrameResize(pSrc, pSrc->height, pSrc->width,
                       pDest->channels, pDest->maxval);
    bFreeSrc = 1; // source is now a temporary copy that needs to be freed
  }

// correct coordinates
  if (destY < 0) {
    height += destY;
    srcY -= destY;
    destY = 0;
  }
  if (destX < 0) {
    width += destX;
    srcX -= destX;
    destX = 0;
  }
  if (srcY < 0) {
    height += srcY;
    destY -= srcY;
    srcY = 0;
  }
  if (srcX < 0) {
    width += srcX;
    destX -= srcX;
    srcX = 0;
  }
  if (height > pDest->height - destY)
    height = pDest->height - destY;
  if (width > pDest->width - destX)
    width = pDest->width - destX;
  if (height > pSrc->height - srcY)
    height = pSrc->height - srcY;
  if (width > pSrc->width - srcX)
    width = pSrc->width - srcX;
  if (height < 0)
    height = 0;
  if (width < 0)
    width = 0;

// copy rectangular area
  destI = destX * pDest->channels;
  srcI = srcX * pSrc->channels;
  for (y = 0, dy = destY, sy = srcY; y < height; y++, dy++, sy++)
    for (x = 0, di = destI, si = srcI; x < width; x++)
      for (c = 0; c < pDest->channels; c++, di++, si++)
        pDest->ppData[dy][di] = pSrc->ppData[sy][si];

// free source if it is a temporary copy
  if (bFreeSrc)
    BlinkenFrameFree(pSrc);
}

void BlinkenFrameRotateCw(stBlinkenFrame *pFrame)
{
  int height, width, channels, y, x, c, i, j;
  unsigned char **ppData;

if (pFrame == NULL)
    return;

// allocate new data array
  height = pFrame->width;
  width = pFrame->height;
  channels = pFrame->channels;
  ppData =
      (unsigned char **)BlinkenMalloc2D(height, width * channels,
                                        sizeof(unsigned char));
  if (ppData == NULL)
    return;

// rotate
  for (y = 0; y < height; y++) {
    for (x = 0, i = 0; x < width; x++) {
      j = y * channels;
      for (c = 0; c < channels; c++, i++, j++)
        ppData[y][i] = pFrame->ppData[width - 1 - x][j];
    }
  }

// use new data array
  pFrame->height = height;
  pFrame->width = width;
  free(pFrame->ppData);
  pFrame->ppData = ppData;
}

void BlinkenFrameRotateCcw(stBlinkenFrame *pFrame)
{
  int height, width, channels, y, x, c, i, j;
  unsigned char **ppData;

if (pFrame == NULL)
    return;

// rotate
  for (y = 0; y < height; y++) {
    for (x = 0, i = 0; x < width; x++) {
      j = (height - 1 - y) * channels;
      for (c = 0; c < channels; c++, i++, j++)
        ppData[y][i] = pFrame->ppData[x][j];
    }
  }

// use new data array
  pFrame->height = height;
  pFrame->width = width;
  free(pFrame->ppData);
  pFrame->ppData = ppData;
}

void BlinkenFrameRotateHalf(stBlinkenFrame *pFrame)
{
  int y1, y2, x1, x2, c, i1, i2;

if (pFrame == NULL)
    return;

for (y1 = 0, y2 = pFrame->height - 1 ; y1 < pFrame->height; y1++, y2--) {
    for (x1 = 0, x2 = pFrame->width - 1,
         i1 = 0, i2 = (pFrame->width - 1) * pFrame->channels;
         x1 < pFrame->width / 2; x1++, x2--, i2 -= 2 * pFrame->channels) {
      for (c = 0; c < pFrame->channels; c++, i1++, i2++) {
        unsigned char tmp = pFrame->ppData[y1][i1];
        pFrame->ppData[y1][i1] = pFrame->ppData[y2][i2];
        pFrame->ppData[y2][i2] = tmp;
      }
    }
  }
}

void BlinkenFrameMirrorHor(stBlinkenFrame *pFrame)
{
  int y, x1, x2, c, i1, i2;

if (pFrame == NULL)
    return;

for (y = 0; y < pFrame->height; y++) {
    for (x1 = 0, x2 = pFrame->width - 1,
         i1 = 0, i2 = (pFrame->width - 1) * pFrame->channels;
         x1 < pFrame->width / 2; x1++, x2--, i2 -= 2 * pFrame->channels) {
      for (c = 0; c < pFrame->channels; c++, i1++, i2++) {
        unsigned char tmp = pFrame->ppData[y][i1];
        pFrame->ppData[y][i1] = pFrame->ppData[y][i2];
        pFrame->ppData[y][i2] = tmp;
      }
    }
  }
}

void BlinkenFrameMirrorVer(stBlinkenFrame *pFrame)
{
  int y1, y2, x, c, i;

if (pFrame == NULL)
    return;

for (y1 = 0, y2 = pFrame->height - 1; y1 < pFrame->height / 2; y1++, y2--) {
    for (x = 0, i = 0; x < pFrame->width; x++) {
      for (c = 0; c < pFrame->channels; c++, i++) {
        unsigned char tmp = pFrame->ppData[y1][i];
        pFrame->ppData[y1][i] = pFrame->ppData[y2][i];
        pFrame->ppData[y2][i] = tmp;
      }
    }
  }
}

void BlinkenFrameMirrorDiag(stBlinkenFrame *pFrame)
{
  int height, width, channels, y, x, c, i, j;
  unsigned char **ppData;

if (pFrame == NULL)
    return;

// mirror
  for (y = 0; y < height; y++) {
    for (x = 0, i = 0; x < width; x++) {
      j = y * channels;
      for (c = 0; c < channels; c++, i++, j++)
        ppData[y][i] = pFrame->ppData[x][j];
    }
  }

// use new data array
  pFrame->height = height;
  pFrame->width = width;
  free(pFrame->ppData);
  pFrame->ppData = ppData;
}

void BlinkenFrameMirrorDiag2(stBlinkenFrame *pFrame)
{
  int height, width, channels, y, x, c, i, j;
  unsigned char **ppData;

if (pFrame == NULL)
    return;

// mirror
  for (y = 0; y < height; y++) {
    for (x = 0, i = 0; x < width; x++) {
      j = (height - 1 - y) * channels;
      for (c = 0; c < channels; c++, i++, j++)
        ppData[y][i] = pFrame->ppData[width - 1 - x][j];
    }
  }

// use new data array
  pFrame->height = height;
  pFrame->width = width;
  free(pFrame->ppData);
  pFrame->ppData = ppData;
}

char *BlinkenFrameToString(stBlinkenFrame *pFrame)
{
  int size, y, x, c, i;
  char *str, *ptr;
  unsigned long val;

if (pFrame == NULL)
    return NULL;

size = pFrame->height * (pFrame->width + 1) + 32;

str = (char *)malloc(size);
  if (str == NULL)
    return NULL;

ptr = str;

for (y = 0; y < pFrame->height; y++) {
    for (x = 0, i = 0; x < pFrame->width; x++) {
      val = 0;
      for (val = 0, c = 0; c < pFrame->channels; c++, i++)
        val += pFrame->ppData[y][i];
      val = val * 7 / pFrame->maxval / pFrame->channels;
      *ptr = " -+*%#&@"[val];
      ptr++;
    }
    *ptr = '\n';
    ptr++;
  }

sprintf(ptr, "%u ms\n", pFrame->duration);

return str;
}

int BlinkenFrameToNetwork(stBlinkenFrame *pFrame, etBlinkenProto proto,
                          char *pData, int maxLength)
// returns length or -1 on error
{
  int y, x, c, i, j, val;

if (pFrame == NULL)
    return -1;

switch (proto) {

case BlinkenProtoNone:
    return 0;

case BlinkenProtoBlp:
    // buffer too short
    if (maxLength < (int)sizeof(stBlinkenProtoBlpHdr) + pFrame->height * pFrame->width)
      return -1;
    // build header
    ((stBlinkenProtoBlpHdr *) pData)->magic = htonl(BlinkenProtoBlpMagic);
    ((stBlinkenProtoBlpHdr *) pData)->frameNo = htonl(0);
    ((stBlinkenProtoBlpHdr *) pData)->width = htons((uint16_t) pFrame->width);
    ((stBlinkenProtoBlpHdr *) pData)->height =
        htons((uint16_t) pFrame->height);
    i = sizeof(stBlinkenProtoBlpHdr);   // put data into packet
    for (y = 0; y < pFrame->height; y++) {
      for (x = 0, j = 0; x < pFrame->width; x++, i++) {
        val = 0;
        for (c = 0; c < pFrame->channels; c++, j++)
          val += pFrame->ppData[y][j];
        pData[i] =
            (val >= pFrame->channels * (pFrame->maxval + 1) / 2 ? 0x01 : 0x00);
      }
    }
    return i;   // return length

case BlinkenProtoEblp:
    // buffer too short
    if (maxLength < (int)sizeof(stBlinkenProtoEblpHdr) + pFrame->height * pFrame->width)
      return -1;
    // build header
    ((stBlinkenProtoEblpHdr *) pData)->magic = htonl(BlinkenProtoEblpMagic);
    ((stBlinkenProtoEblpHdr *) pData)->frameNo = htonl(0);
    ((stBlinkenProtoEblpHdr *) pData)->width =
        htons((uint16_t) pFrame->width);
    ((stBlinkenProtoEblpHdr *) pData)->height =
        htons((uint16_t) pFrame->height);
    i = sizeof(stBlinkenProtoEblpHdr);  // put data into packet
    for (y = 0; y < pFrame->height; y++) {
      for (x = 0, j = 0; x < pFrame->width; x++, i++) {
        val = 0;
        for (c = 0; c < pFrame->channels; c++, j++)
          val += pFrame->ppData[y][j];
        val /= pFrame->channels;
        pData[i] = (pFrame->maxval == 255 ? (unsigned char)val
                    : (unsigned char)((val * 255 + pFrame->maxval / 2) /
                                      pFrame->maxval));
      }
    }
    return i;   // return length

case BlinkenProtoMcuf:
    // buffer too short
    if (maxLength < (int)sizeof(stBlinkenProtoMcufHdr) + pFrame->height * pFrame->width * pFrame->channels)
      return -1;
    // build header
    ((stBlinkenProtoMcufHdr *) pData)->magic = htonl(BlinkenProtoMcufMagic);
    ((stBlinkenProtoMcufHdr *) pData)->height =
        htons((uint16_t) pFrame->height);
    ((stBlinkenProtoMcufHdr *) pData)->width =
        htons((uint16_t) pFrame->width);
    ((stBlinkenProtoMcufHdr *) pData)->channels =
        htons((uint16_t) pFrame->channels);
    ((stBlinkenProtoMcufHdr *) pData)->maxval =
        htons((uint16_t) pFrame->maxval);
    i = sizeof(stBlinkenProtoMcufHdr);  // put data into packet
    for (y = 0; y < pFrame->height; y++)
      for (x = 0, j = 0; x < pFrame->width; x++)
        for (c = 0; c < pFrame->channels; c++, i++, j++)
          pData[i] = pFrame->ppData[y][j];
    return i;   // return length

default:
    return -1;

}
}

stBlinkenFrame *BlinkenFrameFromNetwork(const char *pData, int length,
                                        etBlinkenProto * pProto)
// returns protocol in *pProto if pProto not NULL
{
  stBlinkenFrame *pFrame;
  int height, width, channels, maxval, y, x, c, i, j;

if (length >= (int)sizeof(stBlinkenProtoBlpHdr) &&
      ((stBlinkenProtoBlpHdr *) pData)->magic == htonl(BlinkenProtoBlpMagic))
  {
    if (pProto != NULL) // return protocol
      *pProto = BlinkenProtoBlp;
    // get header data
    height = ntohs(((stBlinkenProtoBlpHdr *) pData)->height);
    width = ntohs(((stBlinkenProtoBlpHdr *) pData)->width);
    // check length of packet
    if (length < (int)sizeof(stBlinkenProtoBlpHdr) + height * width)
      return NULL;
    // check header data
    if (height < BlinkenHeightMin || height > BlinkenHeightMax ||
        width < BlinkenWidthMin || width > BlinkenWidthMax)
      return NULL;
    pFrame = BlinkenFrameNew(height, width, 1, 1, 0);   // create frame
    // according to
    // header data
    if (pFrame == NULL)
      return NULL;
    i = sizeof(stBlinkenProtoBlpHdr);   // put data into frame
    for (y = 0; y < pFrame->height; y++)
      for (x = 0; x < pFrame->width; x++, i++)
        pFrame->ppData[y][x] = pData[i] ? 0x01 : 0x00;
    return pFrame;
  }

if (length >= (int)sizeof(stBlinkenProtoEblpHdr) &&
      ((stBlinkenProtoEblpHdr *) pData)->magic ==
      htonl(BlinkenProtoEblpMagic)) {
    if (pProto != NULL) // return protocol
      *pProto = BlinkenProtoEblp;
    // get header data
    height = ntohs(((stBlinkenProtoEblpHdr *) pData)->height);
    width = ntohs(((stBlinkenProtoEblpHdr *) pData)->width);
    // check length of packet
    if (length < (int)sizeof(stBlinkenProtoEblpHdr) + width * height)
      return NULL;
    // check header data
    if (height < BlinkenHeightMin || height > BlinkenHeightMax ||
        width < BlinkenWidthMin || width > BlinkenWidthMax)
      return NULL;
    pFrame = BlinkenFrameNew(height, width, 1, 255, 0); // create frame
    // according to
    // header data
    if (pFrame == NULL)
      return NULL;
    i = sizeof(stBlinkenProtoEblpHdr);  // put data into frame
    for (y = 0; y < pFrame->height; y++)
      for (x = 0; x < pFrame->width; x++, i++)
        pFrame->ppData[y][x] = pData[i];
    return pFrame;
  }

if (length >= (int)sizeof(stBlinkenProtoMcufHdr) &&
      ((stBlinkenProtoMcufHdr *) pData)->magic ==
      htonl(BlinkenProtoMcufMagic)) {
    if (pProto != NULL) // return protocol
      *pProto = BlinkenProtoMcuf;
    // get header data
    height = ntohs(((stBlinkenProtoMcufHdr *) pData)->height);
    width = ntohs(((stBlinkenProtoMcufHdr *) pData)->width);
    channels = ntohs(((stBlinkenProtoMcufHdr *) pData)->channels);
    maxval = ntohs(((stBlinkenProtoMcufHdr *) pData)->maxval);
    // check length of packet
    if (length < (int)sizeof(stBlinkenProtoMcufHdr) + height * width * channels)
      return NULL;
    // check header data
    if (height < BlinkenHeightMin || height > BlinkenHeightMax ||
        width < BlinkenWidthMin || width > BlinkenWidthMax ||
        channels < BlinkenChannelsMin || channels > BlinkenChannelsMax ||
        maxval < BlinkenMaxvalMin || maxval > BlinkenMaxvalMax)
      return NULL;
    // create frame according to header data
    pFrame = BlinkenFrameNew(height, width, channels, maxval, 0);
    if (pFrame == NULL)
      return NULL;
    i = sizeof(stBlinkenProtoMcufHdr);  // put data into frame
    for (y = 0; y < pFrame->height; y++)
      for (x = 0, j = 0; x < pFrame->width; x++)
        for (c = 0; c < pFrame->channels; c++, i++, j++)
          pFrame->ppData[y][j] = pData[i];
    return pFrame;
  }

if (pProto != NULL)   // return protocol
    *pProto = BlinkenProtoNone;
  return NULL;
}

BlinkenLib

implement getting/setting pixel data