Function lodepng_inspect_chunk

depends/lodepng/lodepng.cpp:4704–4754

#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/

unsigned lodepng_inspect_chunk(LodePNGState* state, size_t pos,
                               const unsigned char* in, size_t insize) {
  const unsigned char* chunk = in + pos;
  unsigned chunkLength;
  const unsigned char* data;
  unsigned unhandled = 0;
  unsigned error = 0;

  if(pos + 4 > insize) return 30;
  chunkLength = lodepng_chunk_length(chunk);
  if(chunkLength > 2147483647) return 63;
  data = lodepng_chunk_data_const(chunk);
  if(data + chunkLength + 4 > in + insize) return 30;

  if(lodepng_chunk_type_equals(chunk, "PLTE")) {
    error = readChunk_PLTE(&state->info_png.color, data, chunkLength);
  } else if(lodepng_chunk_type_equals(chunk, "tRNS")) {
    error = readChunk_tRNS(&state->info_png.color, data, chunkLength);
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
  } else if(lodepng_chunk_type_equals(chunk, "bKGD")) {
    error = readChunk_bKGD(&state->info_png, data, chunkLength);
  } else if(lodepng_chunk_type_equals(chunk, "tEXt")) {
    error = readChunk_tEXt(&state->info_png, data, chunkLength);
  } else if(lodepng_chunk_type_equals(chunk, "zTXt")) {
    error = readChunk_zTXt(&state->info_png, &state->decoder, data, chunkLength);
  } else if(lodepng_chunk_type_equals(chunk, "iTXt")) {
    error = readChunk_iTXt(&state->info_png, &state->decoder, data, chunkLength);
  } else if(lodepng_chunk_type_equals(chunk, "tIME")) {
    error = readChunk_tIME(&state->info_png, data, chunkLength);
  } else if(lodepng_chunk_type_equals(chunk, "pHYs")) {
    error = readChunk_pHYs(&state->info_png, data, chunkLength);
  } else if(lodepng_chunk_type_equals(chunk, "gAMA")) {
    error = readChunk_gAMA(&state->info_png, data, chunkLength);
  } else if(lodepng_chunk_type_equals(chunk, "cHRM")) {
    error = readChunk_cHRM(&state->info_png, data, chunkLength);
  } else if(lodepng_chunk_type_equals(chunk, "sRGB")) {
    error = readChunk_sRGB(&state->info_png, data, chunkLength);
  } else if(lodepng_chunk_type_equals(chunk, "iCCP")) {
    error = readChunk_iCCP(&state->info_png, &state->decoder, data, chunkLength);
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
  } else {
    /* unhandled chunk is ok (is not an error) */
    unhandled = 1;
  }

  if(!error && !unhandled && !state->decoder.ignore_crc) {
    if(lodepng_chunk_check_crc(chunk)) return 57; /*invalid CRC*/
  }

  return error;
}

/*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/
static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h,