pngdetail.cpp

/*
LodePNG pngdetail

Copyright (c) 2005-2018 Lode Vandevenne

This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.

Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:

    1. The origin of this software must not be misrepresented; you must not
    claim that you wrote the original software. If you use this software
    in a product, an acknowledgment in the product documentation would be
    appreciated but is not required.

    2. Altered source versions must be plainly marked as such, and must not be
    misrepresented as being the original software.

    3. This notice may not be removed or altered from any source
    distribution.
*/

//g++ pngdetail.cpp lodepng_util.cpp lodepng.cpp -ansi -pedantic -Wall -Wextra -o pngdetail -O3


/*
Utility program that shows a lot of information in the console about a PNG file,
including color type, text chunks, the names and sizes of all chunks in the
image, all the zlib compression blocks and symbols, etc...

compression info:
./pngdetail -sfczB image.png

everything, 8-bit:
./pngdetail -sPlLA#cfzB7 image.png

everything, 16-bit:
./pngdetail -sPlLA@cfzB7 image.png

everything except huge output:
./pngdetail -sPlAcfzB image.png
*/

#include "lodepng.h"
#include "lodepng_util.h"
#include <iostream>
#include <iomanip>
#include <map>
#include <cmath>
#include <sstream>
#include <algorithm>
#include <stdio.h>
#include <inttypes.h>

void showHelp()
{
  std::cout << "pngdetail by Lode Vandevenne" << std::endl;
  std::cout << "version: " << LODEPNG_VERSION_STRING << std::endl;
  std::cout << "Shows detailed information about a PNG image, its compression and possible corruptions.\n"
               "Usage: pngdetail [filename] [options]...\n"
               "Without options shows a default set of stats. With options, shows only selected options.\n"
               "E.g. 'pngdetail image.png -plc' to show png info, palette info and chunks\n"
               "Options:\n"
               "-s: show header summary on one line\n"
               "-h: show header info\n"
               "-p: show PNG file info\n"
               "-i: show ICC profile in full (if any)\n"
               "--format=<format>: hex display mode for -i:\n"
               "    mix: Use printable ASCII characters, hex for others\n"
               "    hex: Use only hex\n"
               "--size=<width>: render width (not used by hex, hex16 or palette):\n"
               "-l: show palette (if any)\n"
               "-r: render the PNG image in terminal (with --mode and --size)\n"
               "--mode=<mode>: render mode for -r:\n"
               "    ascii:   Letters ROYLGTCABVMF indicate hue (L=lime, T=turquoise, A=azure, F=fuchsia, ...).\n"
               "    hex:     CSS hex notation for every pixel.\n"
               "    hex16:   Like hex but shows 16 bits values per channel.\n"
               "    palette: Shows palette index of each pixel, only for palette images.\n"
               "--size=<width>: render width (not used by hex, hex16 or palette):\n"
               "-c: show PNG chunks\n"
               "-C: show PNG chunks (alternate format)\n"
               "-f: show PNG filters\n"
               "-z: show Zlib info\n"
               "-b: show Zlib blocks\n"
               "-B: show Zlib block symbol counts\n"
               "-7: show all lz77 values (huge output)\n"
               "-v: be more verbose\n"
               "-x: print most integer numbers in hexadecimal (includes e.g. year, num unique colors, ...)\n"
               "-?, --help: show this help" << std::endl;
}

enum RenderMode {
  RM_ASCII,
  RM_HEX, // CSS
  RM_HEX16,
  RM_PAL // palette indices (only rendered if image is palette based)
};

// for displaying ICC profile
enum HexFormat {
  HF_HEX,
  HF_MIX // hex and ascii
};

struct Options
{
  bool verbose;
  bool show_one_line_summary; //show filesize, pixels and color type on single line
  bool show_header;
  bool show_icc; // show ICC color profile in full
  bool show_color_stats;
  bool show_png_info; //show things like filesize, width, height, palette size, ...
  bool show_palette; //show all palette values
  bool show_palette_pixels; //show palette indices of pixels

  HexFormat hexformat;

  bool show_render;
  RenderMode rendermode;
  int rendersize;

  bool show_chunks; //show the PNG chunk names and their lengths
  bool show_chunks2; //alternate form to print chunks
  bool show_filters; //show the PNG filter of each scanline (not supported for interlaced PNGs currently)
  bool zlib_info; //show basic zlib info
  bool zlib_blocks; //show type, tree info, code length summaries and sizes for each zlib block
  bool zlib_counts; //in addition to the zlib_blocks info, show counts of occurrences all symbols
  bool zlib_full; //in addition to the zlib_blocks info, show all symbols, one per line (huge output)
  bool use_hex; //show some sizes or positions in hexadecimal

  Options() : verbose(false), show_one_line_summary(false), show_header(false), show_icc(false),
              show_color_stats(false), show_png_info(false),
              show_palette(false), show_palette_pixels(false),
              hexformat(HF_MIX), show_render(false), rendermode(RM_ASCII), rendersize(80),
              show_chunks(false), show_chunks2(false), show_filters(false),
              zlib_info(false), zlib_blocks(false), zlib_counts(false), zlib_full(false), use_hex(false)
  {
  }
};

unsigned inspect_chunk_by_name(const unsigned char* data, const unsigned char* end,
                               lodepng::State& state, const char type[5])
{
  const unsigned char* p = lodepng_chunk_find_const(data, end, type);
  return lodepng_inspect_chunk(&state, p - data, data, end - data);
}

// Lazy loads the raw file, inspected header or entire image as needed
struct Data
{
  std::string filename;
  std::vector<unsigned char> buffer;
  std::vector<unsigned char> pixels; // 16-bit
  unsigned w;
  unsigned h;
  lodepng::State state;
  unsigned error;
  bool inspected;

  Data(const std::string& filename) : filename(filename), error(0), inspected(false) {}


  // Load the file if not already loaded
  void loadFile()
  {
    if(buffer.empty())
    {
      error = lodepng::load_file(buffer, filename); //load the image file with given filename
    }
    else
    {
      error = 0; // for reloadpixels, reset error if file was already successfully loaded
    }
  }

  // Load header info (plus a few more nearby light chunks) if not already loaded, and the file if needed
  void loadInspect()
  {
    if(inspected) return;
    inspected = true;
    loadFile();
    if(error) return;
    const unsigned char* data = &buffer[0];
    error = lodepng_inspect(&w, &h, &state, data, buffer.size());
    if(error) return;
    // end before first IDAT chunk: do not parse more than first part of file for all this.
    const unsigned char* end = lodepng_chunk_find_const(data, data + buffer.size(), "IDAT");
    if(!end) end = data + buffer.size(); // no IDAT, invalid PNG but extract info anyway
    inspect_chunk_by_name(data, end, state, "PLTE");
    if(error) return;
    inspect_chunk_by_name(data, end, state, "cHRM");
    if(error) return;
    inspect_chunk_by_name(data, end, state, "gAMA");
    if(error) return;
    inspect_chunk_by_name(data, end, state, "sBIT");
    if(error) return;
    inspect_chunk_by_name(data, end, state, "bKGD");
    if(error) return;
    inspect_chunk_by_name(data, end, state, "hIST");
    if(error) return;
    inspect_chunk_by_name(data, end, state, "pHYs");
    if(error) return;
    inspect_chunk_by_name(data, end, state, "iCCP");
    if(error) return;
  }

  // Load the pixels if not already loaded, and the file if needed
  void loadPixels()
  {
    if(pixels.empty()) reloadPixels();
  }

  void reloadPixels()
  {
    loadFile();
    if(error) return;
    inspected = true;
    state.info_raw.colortype = LCT_RGBA;
    state.info_raw.bitdepth = 16;
    pixels.clear();
    error = lodepng::decode(pixels, w, h, state, buffer);
  }
};

std::string colorTypeString(LodePNGColorType type)
{
  std::string name;
  switch(type)
  {
    case LCT_GREY: name = "grey"; break;
    case LCT_RGB: name = "RGB"; break;
    case LCT_PALETTE: name = "palette"; break;
    case LCT_GREY_ALPHA: name = "grey+alpha"; break;
    case LCT_RGBA: name = "RGBA"; break;
    default: name = "invalid"; break;
  }
  std::stringstream ss;
  ss << type << " (" << name << ")";
  return ss.str();
}

template<typename T>
T strtoval(const std::string& s)
{
  std::istringstream sstream(s);
  T val;
  sstream >> val;
  return val;
}


/*
Display the names and sizes of all chunks in the PNG file.
*/
void displayChunkNames(Data& data, const Options& options)
{
  data.loadFile();
  if(data.error) return;
  std::cout << (options.use_hex ? std::hex: std::dec);
  const std::vector<unsigned char>& buffer = data.buffer;
  std::vector<std::string> names;
  std::vector<size_t> sizes;
  unsigned error = lodepng::getChunkInfo(names, sizes, buffer);
  if(error) {
    if(!names.empty() && names.back() == "IEND" && sizes.back() == 0) {
      std::cout << "Corruption or superfluous data detected after the IEND chunk" << std::endl;
    } else {
      std::cout << "Error while identifying chunks. Listing identified chunks anyway." << std::endl;
    }
  }

  if(options.show_chunks2)
  {
    std::cout << "Chunk types: ";
    for(size_t i = 0; i < names.size(); i++) std::cout << names[i] << " ";
    std::cout << std::endl;
    std::cout << "Chunk sizes: ";
    for(size_t i = 0; i < sizes.size(); i++) std::cout << sizes[i] << " ";
    std::cout << std::endl;
  }
  else
  {
    std::cout << "Chunks (type: lengths):";
    std::string last_type;
    for(size_t i = 0; i < names.size(); i++)
    {
      if(last_type != names[i])
      {
        std::cout << std::endl;
        std::cout << " " << names[i] << ": ";
      }
      last_type = names[i];

      std::cout << sizes[i] << " ";
    }
    std::cout << std::endl;
  }

  std::map<std::string, bool> typedict;
  for(size_t i = 0; i < names.size(); i++) {
    typedict[names[i]] = true;
  }

  if(!error) {
    if(!typedict["IHDR"]) std::cout << "Error: no IHDR chunk" << std::endl;
    if(!typedict["IDAT"]) std::cout << "Error: no IDAT chunk" << std::endl;
    if(!typedict["IEND"]) std::cout << "Error: no IEND chunk" << std::endl;
  }
}

void RGBtoHSL(unsigned char r, unsigned char g, unsigned char b, unsigned char* h, unsigned char* s, unsigned char* l) {
  int cmax = std::max<int>(r, std::max<int>(g, b));
  int cmin = std::min<int>(r, std::min<int>(g, b));
  if(cmin == cmax) {
    *h = *s = 0;
    *l = r;
  } else {
    int sum = cmin + cmax;
    int diff = cmax - cmin;
    *l = sum / 2;
    *s = 255 * diff / ((*l < 128) ? sum : (512 - sum));
    int hi = (r == cmax) ? (255 * (g - b) / diff) : ((g == cmax) ? (512 + 255 * (b - r) / diff) : (1024 + 255 * (r - g) / diff));
    *h = ((hi / 6) & 255);
  }
}

/*
HCT: Hue, Chroma, Tone: returns a linear combination between a pure hue and a greyscale value.
*) Chroma: The linear combination factor: 255 for pure hue, 0 for pure greyscale
*) Tone: greyscale to mix with: 0 = black (shade), 255 = white (tint), in between = grey (tone)
*/
void RGBtoHCT(unsigned char r, unsigned char g, unsigned char b, unsigned char* h, unsigned char* c, unsigned char* t) {
  int cmax = std::max<int>(r, std::max<int>(g, b));
  int cmin = std::min<int>(r, std::min<int>(g, b));
  RGBtoHSL(r, g, b, h, c, t);
  *c = cmax - cmin;
  *t = *c == 255 ? 0 : 255 * cmin / (255 + cmin - cmax);
}

// add 32 to get small letter instead of capital
char HueToLetter(int h) {
  char hl = 'R';
  // 12 unique hue letters for 30 degree increment hues.
  if(h < 11 || h >= 244) hl = 'R';  // red
  else if(h >= 11 && h < 32) hl = 'O';  // orange
  else if(h >= 32 && h < 53) hl = 'Y';  // yellow
  else if(h >= 53 && h < 74) hl = 'L';  // lime (officialy "chartreuse" but c is for cyan)
  else if(h >= 74 && h < 96) hl = 'G';  // green
  else if(h >= 96 && h < 117) hl = 'T';  // turquoise (officially "spring green" but that name overlaps green)
  else if(h >= 117 && h < 138) hl = 'C';  // cyan
  else if(h >= 138 && h < 159) hl = 'A';  // azure
  else if(h >= 159 && h < 181) hl = 'B';  // blue
  else if(h >= 181 && h < 202) hl = 'V';  // violet
  else if(h >= 202 && h < 223) hl = 'M';  // magenta
  else if(h >= 223 && h < 244) hl = 'F';  // fuchsia (officially "rose" but r is for red)
  return hl;
}

char lightnessToLetter(int l) {
  int c = ' ';
  if(l < 16) c = ' ';
  else if(l < 48) c = '.';
  else if(l < 80) c = ':';
  else if(l < 112) c = '-';
  else if(l < 144) c = '!';
  else if(l < 176) c = '*';
  else if(l < 208) c = '+'; // The + looks denser than the * in a terminal...
  else if(l < 240) c = '=';
  else c = '#';
  return c;
}

// Both v and result are assumed in range 0-255
// range is the size of an individual bucket. A value in roughly range [-range/2, range/2) can get added to v.
// E.g. if there are 12 hue letters, give 255/12 = 21 as range
static inline int applyDither(int v, int range, int x, int y, bool wrap) {
  // ordered dithering pattern; ranges from 0-15, so multiply with 17 to have 0-255
  static const int pattern[16] = {0,8,2,10,
                                  12,4,14,6,
                                  3,11,1,9,
                                  15,7,13,5};
  int d = pattern[(x & 3) + 4 * (y & 3)] * 17 - 128; // range: -128 to 127
  if(wrap) return (v + d * range / 256) & 255;
  else return std::max(0, std::min(255, v + d * range / 256));
}

// x and y are to use for dithering
// inverted inverts black and white, for in case black text on white background is used (by default it assumes white text on black background)
char RGBtoLetter(unsigned char r, unsigned char g, unsigned char b, unsigned char a, unsigned x, unsigned y, bool dither = true, bool inverted = false) {
  if(a < 255) {
    r = a * r / 255;
    g = a * g / 255;
    b = a * b / 255;
  }

  if(dither) {
    unsigned char h, c, t;
    RGBtoHCT(r, g, b, &h, &c, &t);
    int l = (std::max(std::max(r, g), b) + std::min(std::min(r, g), b)) / 2;
    if(inverted) {
      l = 255 - l;
      t = 255 - t;
    }
    if(applyDither(c, 254, x, y, false) >= 128) {
      char letter = HueToLetter(applyDither(h, 21, x, y, true));
      bool smallcaps = applyDither(l, 64, x+2, y+2, false) < 80;
      return letter + (smallcaps ? 32 : 0);
    }
    else return lightnessToLetter(applyDither(l, 31, x, y, false));
  } else {
    unsigned char h, s, l;
    RGBtoHSL(r, g, b, &h, &s, &l);
    if(inverted) l = 255 - l;

    char hl = HueToLetter(h);
    char c = ' ';
    if(l < 24 || l > 232 || s < 64) {
      c = lightnessToLetter(l);
    } else {
      if(l < 128) c = hl + 32;
      else c = hl;
    }
    return c;
  }
}

std::vector<unsigned char> rescale(const std::vector<unsigned char>& in,
                                   int w0, int h0, int w1, int h1, bool smooth)
{
  int numchannels = in.size() / (w0 * h0);
  std::vector<unsigned char> out(w1 * h1 * numchannels);
  if(smooth)
  {
    // box filter.
    std::vector<unsigned char> temp(w1 * h0 * numchannels);
    for (int c = 0; c < numchannels; c++)
    {
      for (int x = 0; x < w1; x++)
      {
        float xaf = x * 1.0 * w0 / w1;
        float xbf = (x + 1.0) * w0 / w1;
        int xa = (int)xaf;
        int xb = (int)xbf;
        double norm = 1.0 / (xbf - xaf);
        xaf -= std::floor(xaf);
        xbf -= std::floor(xbf);
        for (int y = 0; y < h0; y++)
        {
          int index1 = x * numchannels + y * w1 * numchannels;
          double val = 0;
          for(int x0 = xa; x0 <= xb; x0++)
          {
            int index0 = x0 * numchannels + y * w0 * numchannels;
            double v = 1;
            if(x0 == xa) v -= xaf;
            if(x0 == xb) v -= (1 - xbf);
            val += v * in[index0 + c];
          }
          temp[index1 + c] = val * norm;
        }
      }
      for (int y = 0; y < h1; y++)
      {
        float yaf = y * 1.0 * h0 / h1;
        float ybf = (y + 1.0) * h0 / h1;
        int ya = (int)yaf;
        int yb = (int)ybf;
        double norm = 1.0 / (ybf - yaf);
        yaf -= std::floor(yaf);
        ybf -= std::floor(ybf);
        for (int x = 0; x < w1; x++)
        {
          int index1 = x * numchannels + y * w1 * numchannels;
          double val = 0;
          for(int y0 = ya; y0 <= yb; y0++)
          {
            int index0 = x * numchannels + y0 * w1 * numchannels;
            double v = 1;
            if(y0 == ya) v -= yaf;
            if(y0 == yb) v -= (1 - ybf);
            val += v * temp[index0 + c];
          }
          out[index1 + c] = val * norm;
        }
      }
    }
  } else {
    for(int y = 0; y < h1; y++)
    {
      int y0 = (int)((y + 0.5) * h0 / h1 - 0.5);
      for (int x = 0; x < w1; x++)
      {
        int x0 = (int)((x + 0.5) * w0 / w1 - 0.5);
        int index0 = x0 * numchannels + y0 * w0 * numchannels;
        int index1 = x * numchannels + y * w1 * numchannels;
        for (int c = 0; c < numchannels; c++)
        {
          out[index1 + c] = in[index0 + c];
        }
      }
    }
  }
  return out;
}

/*
Show ASCII art preview of the image
image is given in 16-bit big endian
*/
void displayAsciiArt(const std::vector<unsigned char>& image, unsigned w, unsigned h, unsigned asciiw)
{
  const std::vector<unsigned char>* imagep = &image;
  std::vector<unsigned char> image2;
  if(asciiw < w)
  {
    unsigned w2 = asciiw;
    unsigned h2 = h * w2 / w;
    image2 = rescale(image, w, h, w2, h2, true);
    imagep = &image2;
    w = w2;
    h = h2;
  }
  if(w > 0 && h > 0)
  {
    std::cout << "ASCII Art Preview: " << std::endl;
    unsigned h2 = 1 + ((h - 1) * 4) / 7; //compensate for non-square characters in terminal
    std::cout << '+';
    for(unsigned x = 0; x < w; x++) std::cout << '-';
    std::cout << '+' << std::endl;
    for(unsigned y = 0; y < h2; y++)
    {
      std::cout << "|";
      unsigned y2 = y * h / h2;
      for(unsigned x = 0; x < w; x++)
      {
        int r = (*imagep)[y2 * w * 8 + x * 8 + 0];
        int g = (*imagep)[y2 * w * 8 + x * 8 + 2];
        int b = (*imagep)[y2 * w * 8 + x * 8 + 4];
        int a = (*imagep)[y2 * w * 8 + x * 8 + 6];
        char symbol = RGBtoLetter(r, g, b, a, x, y, true, false);
        std::cout << (char)symbol;
      }
      std::cout << "|";
      std::cout << std::endl;
    }
    std::cout << '+';
    for(unsigned x = 0; x < w; x++) std::cout << '-';
    std::cout << '+' << std::endl;
  }
}

//sixteen: print 16 bits per pixel
//alpha: print alpha channel
//input image ALWAYS given in 16-bit per channel RGBA
void displayColorsHex(const std::vector<unsigned char>& image, unsigned w, unsigned h, bool sixteen)
{
  std::ios_base::fmtflags flags = std::cout.flags();

  if(w > 0 && h > 0)
  {
    std::cout << "Colors (CSS RGBA hex format):" << std::endl;

    for(unsigned y = 0; y < h; y++)
    {
      std::cout.flags(flags); //print line numbers in hex or dec whatever it originally was
      std::cout << y << ":";
      for(unsigned x = 0; x < w; x++)
      {
        size_t index = y * w * 8 + x * 8;
        if (sixteen)
        {
          int r = image[index + 0] * 256 + image[index + 1];
          int g = image[index + 2] * 256 + image[index + 3];
          int b = image[index + 4] * 256 + image[index + 5];
          int a = image[index + 6] * 256 + image[index + 7];
          std::cout << std::hex << std::setfill('0') << " #" << std::setw(4) << r << std::setw(4) << g << std::setw(4) << b << std::setw(4) << a;
        }
        else
        {
          int r = image[index + 0];
          int g = image[index + 2];
          int b = image[index + 4];
          int a = image[index + 6];
          std::cout << std::hex << std::setfill('0') << " #" << std::setw(2) << r << std::setw(2) << g << std::setw(2) << b << std::setw(2) << a;
        }
      }
      std::cout << std::endl;
    }
  }

  std::cout.flags(flags);
}


/*
Show the filtertypes of each scanline in this PNG image.
*/
void displayFilterTypes(Data& data, const Options& options)
{
  std::cout << (options.use_hex ? std::hex: std::dec);
  data.loadFile();
  if(data.error) return;
  const std::vector<unsigned char>& buffer = data.buffer;
  std::vector<std::vector<unsigned char> > types;
  unsigned error = lodepng::getFilterTypesInterlaced(types, buffer);
  if(error)
  {
    std::cout << "Error getting filter types" << std::endl;
    return;
  }

  if(types.size() == 7)
  {
    std::cout << "Filter types (Adam7 interlaced):" << std::endl;
    for(int j = 0; j < 7; j++)
    {
      std::cout << " Pass " << (j + 1) << ": ";
      for(size_t i = 0; i < types[j].size(); i++)
      {
        std::cout << (int)(types[j][i]);
      }
      std::cout << std::endl;
    }
  }
  else
  {
    std::cout << "Filter types: ";
    for(size_t i = 0; i < types[0].size(); i++)
    {
      std::cout << (int)(types[0][i]);
    }
    std::cout << std::endl;
  }
}

//image type MUST be palette
void displayPalette(Data& data, const Options& options)
{
  data.loadInspect();
  if(data.error) return;
  std::cout << (options.use_hex ? std::hex: std::dec);

  const LodePNGInfo& info = data.state.info_png;
  const LodePNGColorMode& color = info.color;

  std::cout << "Palette size: " << color.palettesize << std::endl;
  std::cout << "Palette colors: ";
  std::ios_base::fmtflags flags = std::cout.flags();
  std::cout << std::hex << std::setfill('0');
  for(size_t i = 0; i < color.palettesize; i++)
  {
    unsigned char* p = &color.palette[i * 4];
    std::cout << "#" << std::setw(2) << (int)p[0] << std::setw(2) << (int)p[1] << std::setw(2) << (int)p[2] << std::setw(2) << (int)p[3] << " ";
  }
  std::cout.flags(flags);
  std::cout << std::endl;
}

//image type MUST be palette
void displayPalettePixels(const std::vector<unsigned char>& buffer, const Options& options)
{
  unsigned w, h;
  lodepng::State state;
  std::vector<unsigned char> out;
  std::cout << (options.use_hex ? std::hex: std::dec);

  state.decoder.color_convert = 0;

  lodepng::decode(out, w, h, state, buffer);

  if(state.info_png.color.colortype == LCT_PALETTE)
  {
    if (options.show_color_stats)
    {
      std::vector<size_t> count(256, 0);
      size_t outofbounds = 0;

      for(size_t i = 0; i < w * h; i++)
      {
        int value = lodepng::getPaletteValue(&out[0], i, state.info_raw.bitdepth);
        count[value]++;
        if(value >= (int)state.info_raw.palettesize) outofbounds++;
      }

      std::cout << "Palette count: ";
      for(size_t i = 0; i < state.info_raw.palettesize; i++)
      {
        std::cout << count[i] << " ";
      }
      std::cout << std::endl;

      if(outofbounds > 0) std::cout << "Out of bounds palette values: " << outofbounds << std::endl;
    }

    std::cout << "Pixel palette indices:" << std::endl;
    for(size_t i = 0; i < w * h; i++)
    {
      int value = lodepng::getPaletteValue(&out[0], i, state.info_raw.bitdepth);
      std::cout << value << ", ";
      if(i % w == w - 1) std::cout << std::endl;
    }
  }
  else
  {
    std::cout << "Pixel palette indices: not shown, not a palette image\n" << std::endl;
  }
}

void printZlibInfo(Data& data, const Options& options)
{
  data.loadFile();
  if(data.error) return;
  const std::vector<unsigned char>& in = data.buffer;
  std::cout << (options.use_hex ? std::hex: std::dec);

  std::vector<lodepng::ZlibBlockInfo> zlibinfo;
  lodepng::extractZlibInfo(zlibinfo, in);

  if(options.zlib_info)
  {
    //std::cout << "Zlib info: " << std::endl;
    size_t compressed = 0;
    size_t uncompressed = 0;
    std::vector<size_t> boundaries_compressed;
    std::vector<size_t> boundaries_uncompressed;
    for(size_t i = 0; i < zlibinfo.size(); i++)
    {
      compressed += zlibinfo[i].compressedbits / 8;
      uncompressed += zlibinfo[i].uncompressedbytes;
      boundaries_compressed.push_back(compressed);
      boundaries_uncompressed.push_back(uncompressed);
    }

    std::cout << "IDAT zlib info: " << compressed << std::endl;
    std::cout << "Compressed size: " << compressed << std::endl;
    std::cout << "Uncompressed size: " << uncompressed << std::endl;
    std::cout << "Amount of zlib blocks: " << zlibinfo.size() << std::endl;
    if(zlibinfo.size() > 1)
    {
      std::cout << "Block sizes (uncompressed): ";
      for(size_t i = 0; i < zlibinfo.size(); i++)
          std::cout << zlibinfo[i].uncompressedbytes << " ";
      std::cout << std::endl;
      std::cout << "Block sizes (compressed): ";
      for(size_t i = 0; i < zlibinfo.size(); i++)
          std::cout << (zlibinfo[i].compressedbits / 8) << " ";
      std::cout << std::endl;
      std::cout << "Block boundaries (uncompressed): ";
      for(size_t i = 0; i + 1 < boundaries_uncompressed.size(); i++)
          std::cout << boundaries_uncompressed[i] << " ";
      std::cout << std::endl;
      std::cout << "Block boundaries (compressed): ";
      for(size_t i = 0; i + 1 < boundaries_compressed.size(); i++)
          std::cout << boundaries_compressed[i] << " ";
      std::cout << std::endl;
    }
  }

  if(options.zlib_blocks)
  {
    for(size_t i = 0; i < zlibinfo.size(); i++)
    {
      const lodepng::ZlibBlockInfo& info = zlibinfo[i];

      std::cout << "Zlib block " << i << ":" << std::endl;
      std::cout << " block type: " << info.btype << std::endl;

      size_t compressedsize = info.compressedbits / 8;
      size_t uncompressedsize = info.uncompressedbytes;
      std::cout << " block compressed: " << compressedsize << " (" << compressedsize / 1024 << "K) (" << info.compressedbits << " bits)" << std::endl;
      std::cout << " block uncompressed: " << uncompressedsize << " (" << uncompressedsize / 1024 << "K)" << std::endl;

      if(info.btype > 2)
      {
        std::cout << "Error: Invalid Block Type" << std::endl;
        return;
      }

      if(info.btype == 2)
      {
        std::cout << " encoded trees size: " << info.treebits / 8 << " (" << info.treebits << " bits)" << std::endl;
        std::cout << " HLIT: " << info.hlit << std::endl;
        std::cout << " HDIST: " << info.hdist << std::endl;
        std::cout << " HCLEN: " << info.hclen << std::endl;
        std::cout << std::hex;
        std::cout << " code length code lengths: "; for(size_t j = 0; j < 19; j++) std::cout << info.clcl[j]; std::cout << std::endl;
        if(!options.use_hex) std::cout << std::dec;
        if(options.zlib_full)
        {
          for(size_t j = 0; j < info.treecodes.size(); j++)
          {
            int code = info.treecodes[j];
            if(code < 17)
            {
               std::cout << " tree: " << code << std::endl;
            }
            else
            {
              j++;
              std::cout << " tree: " << code << " rep: " << info.treecodes[j] << std::endl;
            }

          }
        }

        std::cout << std::hex;
        std::cout << " lit code lengths 0-127  : "; for(size_t j = 0; j < 128; j++) std::cout << info.litlenlengths[j]; std::cout << std::endl;
        std::cout << " lit code lengths 128-255: "; for(size_t j = 128; j < 256; j++) std::cout << info.litlenlengths[j]; std::cout << std::endl;
        std::cout << " end code length         : "; std::cout << info.litlenlengths[256]; std::cout << std::endl;
        std::cout << " len code lengths        : "; for(size_t j = 257; j < 288; j++) std::cout << info.litlenlengths[j]; std::cout << std::endl;
        std::cout << " dist code lengths       : "; for(size_t j = 0; j < 32; j++) std::cout << info.distlengths[j]; std::cout << std::endl;
        if(!options.use_hex) std::cout << std::dec;
      }


      if(info.btype != 0)
      {
        std::cout << " code counts: lit: " << info.numlit << ", len/dist: " << info.numlen << ", total: " << (info.numlit + info.numlen + 1) << ", with dists: " << (info.numlit + 2 * info.numlen + 1) << std::endl;

        if(options.zlib_full)
        {
          for(size_t j = 0; j < info.lz77_lcode.size(); j++)
          {
            int symbol = info.lz77_lcode[j];
            if(symbol == 256)
            {
              std::cout << " end" << std::endl;
            }
            else if(symbol < 256)
            {
              std::cout << " lit: " << symbol << std::endl;
            }
            else
            {
              std::cout << " len: " << info.lz77_lvalue[j] << ", dist: " << info.lz77_dvalue[j] << std::endl;
            }
          }
        }

        if(options.zlib_counts)
        {
          std::vector<size_t> ll_count(288, 0);
          std::vector<size_t> d_count(32, 0);
          for(size_t j = 0; j < info.lz77_lcode.size(); j++)
          {
            int symbol = info.lz77_lcode[j];
            if(symbol <= 256)
            {
              ll_count[symbol]++;
            }
            else
            {
              ll_count[symbol]++;
              d_count[info.lz77_dcode[j]]++;
            }
          }
          std::cout << " lit code 0-63 counts   : "; for(size_t j = 0; j < 64; j++) std::cout << ll_count[j] << " "; std::cout << std::endl;
          std::cout << " lit code 64-127 counts : "; for(size_t j = 64; j < 128; j++) std::cout << ll_count[j] << " "; std::cout << std::endl;
          std::cout << " lit code 128-191 counts: "; for(size_t j = 128; j < 192; j++) std::cout << ll_count[j] << " "; std::cout << std::endl;
          std::cout << " lit code 192-255 counts: "; for(size_t j = 192; j < 256; j++) std::cout << ll_count[j] << " "; std::cout << std::endl;
          std::cout << " end code count         : "; std::cout << ll_count[256] << " "; std::cout << std::endl;
          std::cout << " len code counts        : "; for(size_t j = 257; j < 288; j++) std::cout << ll_count[j] << " "; std::cout << std::endl;
          std::cout << " dist code counts       : "; for(size_t j = 0; j < 32; j++) std::cout << d_count[j] << " "; std::cout << std::endl;
        }
      }
    }
  }
}

// returns number of unique RGBA colors in the image
// also fills unique r, g, b, a counts in the output parameters
// the input image is in 16-bit per channel color, so 8 chars per pixel
size_t countColors(std::vector<unsigned char> image, unsigned w, unsigned h,
    size_t* ro, size_t* go, size_t* bo, size_t* ao) {
  typedef std::pair<std::pair<unsigned short, unsigned short>, std::pair<unsigned short, unsigned short> > RGBA;
  std::map<RGBA, size_t> rgbam;
  //std::map<uint64_t, size_t> rgbam;
  std::vector<unsigned char> rm(65536, 0);
  std::vector<unsigned char> gm(65536, 0);
  std::vector<unsigned char> bm(65536, 0);
  std::vector<unsigned char> am(65536, 0);
  for(unsigned y = 0; y < h; y++) {
    for(unsigned x = 0; x < w; x++) {
      unsigned short r = 256 * image[y * 8 * w + x * 8 + 0] + image[y * 8 * w + x * 8 + 1];
      unsigned short g = 256 * image[y * 8 * w + x * 8 + 2] + image[y * 8 * w + x * 8 + 3];
      unsigned short b = 256 * image[y * 8 * w + x * 8 + 4] + image[y * 8 * w + x * 8 + 5];
      unsigned short a = 256 * image[y * 8 * w + x * 8 + 6] + image[y * 8 * w + x * 8 + 7];
      RGBA rgba(std::make_pair(r, g), std::make_pair(b, a));
      //uint64_t rgba = (uint64_t)r + ((uint64_t)g << 16) + ((uint64_t)b << 32) + ((uint64_t)a << 48);
      rgbam[rgba]++;
      rm[r] = 1;
      gm[g] = 1;
      bm[b] = 1;
      am[a] = 1;
    }
  }
  *ro = *go = *bo = *ao = 0;
  for(size_t i = 0; i < rm.size(); i++)
  {
    *ro += rm[i];
    *go += gm[i];
    *bo += bm[i];
    *ao += am[i];
  }

  return rgbam.size();
}


void showError(Data& data, const Options& options)
{
  std::cout << (options.use_hex ? std::hex: std::dec);
  std::string prefix = (options.use_hex ? "0x": "");
  if(!data.error)
  {
    std::cout << "No error" << std::endl;
  }
  std::cout << "Decoding error " << prefix << data.error << ": " << lodepng_error_text(data.error) << std::endl;
}

void loadWithErrorRecovery(Data& data, const Options& options)
{
  (void)options;
  unsigned& error = data.error;
  lodepng::State& state = data.state;

  data.loadPixels();

  // In case of checksum errors and some other ignorable errors, report it but ignore it and retry
  while(error)
  {
    // Not showing regular error here, is shown at end of program.
    unsigned error2 = error;
    if(error == 57)
    {
      showError(data, options);
      std::cerr << "Ignoring the error: enabling ignore_crc" << std::endl;
      state.decoder.ignore_crc = 1;
      data.reloadPixels();
    }
    else if(error == 58)
    {
      showError(data, options);
      std::cerr << "Ignoring the error: enabling ignore_adler32" << std::endl;
      state.decoder.zlibsettings.ignore_adler32 = 1;
      data.reloadPixels();
    }
    else if(error == 69)
    {
      showError(data, options);
      std::cerr << "Ignoring the error: enabling ignore_critical" << std::endl;
      state.decoder.ignore_critical = 1;
      data.reloadPixels();
    }
    else if(error == 30 || error == 63)
    {
      showError(data, options);
      std::cerr << "Ignoring the error: enabling ignore_end" << std::endl;
      state.decoder.ignore_end = 1;
      data.reloadPixels();
    }
    else
    {
      if(error == 0) std::cerr << "This error is unrecoverable" << std::endl;
      break;  // other error that we cannot ignore
    }
    if(error == 0) std::cerr << "Successfully ignored the error" << std::endl;
    if(error == error2)
    {
      std::cerr << "Failed to ignore the error" << std::endl;
      break; // avoid infinite loop if ignoring did not fix the error code
    }
  }
}




void showSingleLineSummary(Data& data, const Options& options)
{
  data.loadInspect();
  if(data.error) return;
  std::cout << (options.use_hex ? std::hex: std::dec);

  std::cout << "Filesize: " << data.buffer.size() << " (" << data.buffer.size() / 1024 << "K)" << ", ";
  std::cout << data.w << "x" << data.h << ", ";
  std::cout << "Color: " << colorTypeString(data.state.info_png.color.colortype) << ", " << data.state.info_png.color.bitdepth << " bit" << std::endl;
}

void showHeaderInfo(Data& data, const Options& options)
{
  data.loadInspect();
  if(data.error) return;
  std::cout << (options.use_hex ? std::hex: std::dec);

  const LodePNGInfo& info = data.state.info_png;
  const LodePNGColorMode& color = info.color;
  if(options.show_header)
  {
    std::cout << "Filesize: " << data.buffer.size() << " (" << data.buffer.size() / 1024 << "K)" << std::endl;
    std::cout << "Width: " << data.w << std::endl;
    std::cout << "Height: " << data.h << std::endl;
    std::cout << "Interlace method: " << info.interlace_method << std::endl;
    if(options.verbose)
    {
      std::cout << "Compression method: " << info.compression_method << std::endl;
      std::cout << "Filter method: " << info.filter_method << std::endl;
    }
    std::cout << "Color type: " << colorTypeString(color.colortype) << std::endl;
    std::cout << "Bit depth: " << color.bitdepth << std::endl;
    if(options.verbose)
    {
      std::cout << "Bits per pixel: " << lodepng_get_bpp(&color) << std::endl;
      std::cout << "Channels per pixel: " << lodepng_get_channels(&color) << std::endl;
      std::cout << "Is greyscale type: " << lodepng_is_greyscale_type(&color) << std::endl;
      std::cout << "Can have alpha: " << lodepng_can_have_alpha(&color) << std::endl;
      std::cout << "Has color key: " << color.key_defined << std::endl;
    }
    if (color.colortype == LCT_PALETTE)
    {
      std::cout << "Palette size: " << color.palettesize << std::endl;
    }
    if(color.key_defined)
    {
      std::cout << "Color key rgb: " << color.key_r
                << ", " << color.key_g
                << ", " << color.key_b << std::endl;
    }
    if(info.background_defined)
    {
      if(color.colortype == LCT_PALETTE)
      {
        std::cout << "Background index: " << info.background_r << std::endl;
      }
      else
      {
        std::cout << "Background rgb: " << info.background_r
                  << ", " << info.background_g
                  << ", " << info.background_b << std::endl;
      }
    }
    if(info.gama_defined)
    {
      std::cout << "gAMA defined: " << info.gama_gamma << " (" << (info.gama_gamma / 100000.0)
                << ", " << (100000.0 / info.gama_gamma) << ")" << std::endl;
    }
    if(info.chrm_defined)
    {
      std::cout << "cHRM defined: w: " << (info.chrm_white_x / 100000.0) << " " << (info.chrm_white_y / 100000.0)
                << ", r: " << (info.chrm_red_x / 100000.0) << " " << (info.chrm_red_y / 100000.0)
                << ", g: " << (info.chrm_green_x / 100000.0) << " " << (info.chrm_green_y / 100000.0)
                << ", b: " << (info.chrm_blue_x / 100000.0) << " " << (info.chrm_blue_y / 100000.0)
                << std::endl;
    }
    if(info.srgb_defined)
    {
      std::cout << "sRGB defined: rendering intent: " << info.srgb_intent << std::endl;
    }
    if(info.iccp_defined)
    {
      std::cout << "iCCP defined: (" << info.iccp_profile_size << " bytes), name: " << info.iccp_name << std::endl;
      if(options.verbose && !options.show_icc) std::cout << "Use -i to show full ICC profile" << std::endl;
    }
  }
  if(info.iccp_defined && options.show_icc)
  {
    for(size_t i = 0; i < info.iccp_profile_size; i++) {
      unsigned char c = info.iccp_profile[i];
      if(c > 32 && c < 127 && options.hexformat == HF_MIX) printf(" %c ", c);
      else printf("%02x ", c);
      if(i % 40 == 39 && i + 1 != info.iccp_profile_size) std::cout << std::endl;
    }
    std::cout << std::endl;
  }

  if(options.show_header)
  {
    if(options.verbose) std::cout << "Physics defined: " << info.phys_defined << std::endl;
    if(info.phys_defined)
    {
      std::cout << "Physics: X: " << info.phys_x << ", Y: " << info.phys_y << ", unit: " << info.phys_unit << std::endl;
    }
  }
}

// A bit more PNG info, which is from chunks that can come after IDAT. showHeaderInfo shows most other stuff.
void showPNGInfo(Data& data, const Options& options)
{
  loadWithErrorRecovery(data, options);
  if(data.error) return;
  std::cout << (options.use_hex ? std::hex: std::dec);

  const LodePNGInfo& info = data.state.info_png;

  if(options.verbose) std::cout << "Texts: " << info.text_num << std::endl;
  for(size_t i = 0; i < info.text_num; i++)
  {
    std::cout << "Text: " << info.text_keys[i] << ": " << info.text_strings[i] << std::endl;
  }
  if(options.verbose) std::cout << "International texts: " << info.itext_num << std::endl;
  for(size_t i = 0; i < info.itext_num; i++)
  {
    std::cout << "Text: "
              << info.itext_keys[i] << ", "
              << info.itext_langtags[i] << ", "
              << info.itext_transkeys[i] << ": "
              << info.itext_strings[i] << std::endl;
  }
  if(options.verbose) std::cout << "Time defined: " << info.time_defined << std::endl;
  if(info.time_defined)
  {
    const LodePNGTime& time = info.time;
    std::cout << "year: " << time.year << std::endl;
    std::cout << "month: " << time.month << std::endl;
    std::cout << "day: " << time.day << std::endl;
    std::cout << "hour: " << time.hour << std::endl;
    std::cout << "minute: " << time.minute << std::endl;
    std::cout << "second: " << time.second << std::endl;
  }
}

void showColorStats(Data& data, const Options& options)
{
  std::cout << (options.use_hex ? std::hex: std::dec);
  std::vector<unsigned char>& image = data.pixels;
  unsigned& w = data.w;
  unsigned& h = data.h;

  data.loadPixels();
  if(data.error) return;
  // TODO: move to show color stats function
  if(options.verbose) std::cout << "Num pixels: " << w * h << std::endl;
  size_t rc, gc, bc, ac;
  std::cout << "Num unique colors: " << countColors(image, w, h, &rc, &gc, &bc, &ac);
  std::cout << " (r: " << rc << ", g: " << gc << ", b: " << bc << ", a: " << ac << ")";
  std::cout << std::endl;
  if(w > 0 && h > 0)
  {
    double avg[4] = {0, 0, 0, 0};
    double min[4] = {999999, 999999, 999999, 999999};
    double max[4] = {0, 0, 0, 0};
    for(unsigned y = 0; y < h; y++) {
      for(unsigned x = 0; x < w; x++) {
        for(int c = 0; c < 4; c++) {
          double v = 256 * image[y * 8 * w + x * 8 + c * 2] + image[y * 8 * w + x * 8 + c * 2 + 1];
          avg[c] += v;
          min[c] = std::min(min[c], v);
          max[c] = std::max(max[c], v);
        }
      }
    }
    for(int c = 0; c < 4; c++) {
      avg[c] /= (w * h * 257.0);
      min[c] /= 257.0;
      max[c] /= 257.0;
    }
    if(options.verbose) std::cout << "Ranges shown as 0.0-255.0, even for 16-bit data:" << std::endl;
    std::cout << "Average color: " << avg[0] << ", " << avg[1] << ", " << avg[2] << ", " << avg[3] << std::endl;
    std::cout << "Color ranges: " << min[0] << "-" << max[0] << ", " << min[1] << "-" << max[1] << ", " << min[2] << "-" << max[2] << ", " << min[3] << "-" << max[3] << std::endl;
  }
}

void showRender(Data& data, const Options& options)
{
  data.loadPixels();
  if(data.error) return;
  if(options.rendermode == RM_ASCII)
  {
    displayAsciiArt(data.pixels, data.w, data.h, options.rendersize);
  }

  if(options.rendermode == RM_HEX)
  {
    displayColorsHex(data.pixels, data.w, data.h, false);
  }

  if(options.rendermode == RM_HEX16)
  {
    displayColorsHex(data.pixels, data.w, data.h, true);
  }

  if(options.rendermode == RM_PAL)
  {
    displayPalettePixels(data.buffer, options);
  }
}


void showInfos(Data& data, const Options& options)
{
  if(options.show_one_line_summary) showSingleLineSummary(data, options);
  if(options.show_header || options.show_icc) showHeaderInfo(data, options);
  if(options.show_color_stats) showColorStats(data, options);
  if(options.show_png_info) showPNGInfo(data, options);
  if(options.show_palette) displayPalette(data, options);
  if(options.show_chunks || options.show_chunks2) displayChunkNames(data, options);
  if(options.show_filters) displayFilterTypes(data, options);
  if(options.show_render) showRender(data, options);
  if(options.zlib_info || options.zlib_blocks || options.zlib_counts || options.zlib_full)
  {
    printZlibInfo(data, options);
  }

  if(data.error) showError(data, options);
}

int main(int argc, char *argv[])
{
  Options options;
  bool options_chosen = false;

  std::vector<std::string> filenames;
  for (int i = 1; i < argc; i++)
  {
    std::string s = argv[i];
    if(s.size() > 1 && s[0] == '-' && s[1] != '-')
    {
      // anything that chooses actual set disables the defaults
      if(s != "-x" && s != "-v") options_chosen = true;
      for(size_t j = 1; j < s.size(); j++)
      {
        char c = s[j];
        if(c == '?')
        {
          showHelp();
          return 0;
        }
        else if(c == 'o') options.show_one_line_summary = true;
        else if(c == 'h') options.show_header = true;
        else if(c == 'i') options.show_icc = true;
        else if(c == 'v') options.verbose = true;
        else if(c == 's') options.show_color_stats = true;
        else if(c == 'p') options.show_header = options.show_png_info = true;
        else if(c == 'r') options.show_render = true;
        else if(c == 'l') options.show_palette = true;
        else if(c == 'L') options.show_palette_pixels = true;
        else if(c == 'c') options.show_chunks = true;
        else if(c == 'C') options.show_chunks2 = true;
        else if(c == 'f') options.show_filters = true;
        else if(c == 'z') options.zlib_info = true;
        else if(c == 'b') options.zlib_blocks = true;
        else if(c == 'B')
        {
          options.zlib_blocks = true;
          options.zlib_counts = true;
        }
        else if(c == '7')
        {
          options.zlib_blocks = true;
          options.zlib_full = true;
        }
        else if(c == 'x')
        {
          options.use_hex = true;
          std::cout << std::hex;
        }
        else if(c == '-')
        {
          if(s != "--help") std::cout << "Unknown flag: " << s << ". Use -h for help" << std::endl;
          showHelp();
          return 0;
        }
        else
        {
          std::cout << "Unknown flag: " << c << ". Use -h for help" << std::endl;
          showHelp();
          return 0;
        }

      }
    }
    else if(s.size() > 1 && s[0] == '-' && s[1] == '-')
    {
      size_t eqpos = 2;
      while(eqpos < s.size() && s[eqpos] != '=') eqpos++;
      std::string key = s.substr(2, eqpos - 2);
      std::string value = (eqpos + 1) < s.size() ? s.substr(eqpos + 1) : "";
      if(key == "help")
      {
        showHelp();
        return 0;
      }
      if(key == "mode")
      {
        if(value == "ascii") options.rendermode = RM_ASCII;
        else if(value == "hex") options.rendermode = RM_HEX;
        else if(value == "hex16") options.rendermode = RM_HEX16;
        else if(value == "palette") options.rendermode = RM_PAL;
      }
      if(key == "size")
      {
        int size = strtoval<int>(value);
        if(options.rendersize >= 1 && options.rendersize <= 4096) options.rendersize = size;
      }
      if(key == "format")
      {
        if(value == "mix") options.hexformat = HF_MIX;
        else if(value == "hex") options.hexformat = HF_HEX;
      }
    }
    else filenames.push_back(s);
  }

  if(filenames.empty())
  {
    std::cout << "Please provide a filename to preview" << std::endl;
    showHelp();
    return 0;
  }

  if(!options_chosen)
  {
    //fill in defaults
    options.show_header = true;
  }

  for(size_t i = 0; i < filenames.size(); i++)
  {
    if(filenames.size() > 1) {
      if(i > 0 && !options.show_one_line_summary) std::cout << std::endl;
      std::cout << filenames[i] << ":";
      if(!options.show_one_line_summary) std::cout << std::endl; else std::cout << " ";
    }
    Data data(filenames[i]);
    showInfos(data, options);
  }
}