C++ png_debug函数代码示例

void png_read_filter_row_paeth4_sse2(png_row_infop row_info, png_bytep row,
   png_const_bytep prev)
{
   /* Paeth tries to predict pixel d using the pixel to the left of it, a,
    * and two pixels from the previous row, b and c:
    *   prev: c b
    *   row:  a d
    * The Paeth function predicts d to be whichever of a, b, or c is nearest to
    * p=a+b-c.
    *
    * The first pixel has no left context, and so uses an Up filter, p = b.
    * This works naturally with our main loop's p = a+b-c if we force a and c
    * to zero.
    * Here we zero b and d, which become c and a respectively at the start of
    * the loop.
    */
   png_size_t rb;
   const __m128i zero = _mm_setzero_si128();
   __m128i pa,pb,pc,smallest,nearest;
   __m128i c, b = zero,
           a, d = zero;

   png_debug(1, "in png_read_filter_row_paeth4_sse2");

   rb = row_info->rowbytes+4;
   while (rb > 4) {
      /* It's easiest to do this math (particularly, deal with pc) with 16-bit
       * intermediates.
       */
      c = b; b = _mm_unpacklo_epi8(load4(prev), zero);
      a = d; d = _mm_unpacklo_epi8(load4(row ), zero);

      /* (p-a) == (a+b-c - a) == (b-c) */
      pa = _mm_sub_epi16(b,c);

      /* (p-b) == (a+b-c - b) == (a-c) */
      pb = _mm_sub_epi16(a,c);

      /* (p-c) == (a+b-c - c) == (a+b-c-c) == (b-c)+(a-c) */
      pc = _mm_add_epi16(pa,pb);

      pa = abs_i16(pa);  /* |p-a| */
      pb = abs_i16(pb);  /* |p-b| */
      pc = abs_i16(pc);  /* |p-c| */

      smallest = _mm_min_epi16(pc, _mm_min_epi16(pa, pb));

      /* Paeth breaks ties favoring a over b over c. */
      nearest  = if_then_else(_mm_cmpeq_epi16(smallest, pa), a,
                         if_then_else(_mm_cmpeq_epi16(smallest, pb), b,
                                                                     c));

      /* Note `_epi8`: we need addition to wrap modulo 255. */
      d = _mm_add_epi8(d, nearest);
      store4(row, _mm_packus_epi16(d,d));

      prev += 4;
      row  += 4;
      rb   -= 4;
   }
}

/* Alternate initialize png_ptr structure, and allocate any memory needed */
png_structp
png_create_write_struct_2(png_const_charp user_png_ver, png_voidp error_ptr,
   png_error_ptr error_fn, png_error_ptr warn_fn, png_voidp mem_ptr,
   png_malloc_ptr malloc_fn, png_free_ptr free_fn)
{
#endif /* PNG_USER_MEM_SUPPORTED */
   png_structp png_ptr;
#ifdef USE_FAR_KEYWORD
   jmp_buf jmpbuf;
#endif
   png_debug(1, "in png_create_write_struct\n");
#ifdef PNG_USER_MEM_SUPPORTED
   if ((png_ptr = (png_structp)png_create_struct_2(PNG_STRUCT_PNG,
      (png_malloc_ptr)malloc_fn)) == NULL)
#else
   if ((png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG)) == NULL)
#endif /* PNG_USER_MEM_SUPPORTED */
   {
      return ((png_structp)NULL);
   }
#ifdef USE_FAR_KEYWORD
   if (setjmp(jmpbuf))
#else
   if (setjmp(png_ptr->jmpbuf))
#endif
   {
      png_free(png_ptr, png_ptr->zbuf);
      png_destroy_struct(png_ptr);
      return ((png_structp)NULL);
   }
#ifdef USE_FAR_KEYWORD
   png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf));
#endif
#ifdef PNG_USER_MEM_SUPPORTED
   png_set_mem_fn(png_ptr, mem_ptr, malloc_fn, free_fn);
#endif /* PNG_USER_MEM_SUPPORTED */
   png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn);

   /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so
    * we must recompile any applications that use any older library version.
    * For versions after libpng 1.0, we will be compatible, so we need
    * only check the first digit.
    */
   if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] ||
       (png_libpng_ver[0] == '0' && user_png_ver[2] < '9'))
   {
      png_error(png_ptr,
         "Incompatible libpng version in application and library");
   }

   /* initialize zbuf - compression buffer */
   png_ptr->zbuf_size = PNG_ZBUF_SIZE;
   png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
      (png_uint_32)png_ptr->zbuf_size);

   png_set_write_fn(png_ptr, NULL, NULL, NULL);

#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED)
   png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT,
      1, NULL, NULL);
#endif

   return ((png_structp)png_ptr);
}

/* Allow the application to select one or more row filters to use. */
void
png_set_filter(png_structp png_ptr, int method, int filters)
{
   png_debug(1, "in png_set_filter\n");
   /* We allow 'method' only for future expansion of the base filter method. */
   if (method == PNG_FILTER_TYPE_BASE)
   {
      switch (filters & (PNG_ALL_FILTERS | 0x07))
      {
         case 5:
         case 6:
         case 7: png_warning(png_ptr, "Unknown row filter for method 0");
         case PNG_FILTER_VALUE_NONE:  png_ptr->do_filter=PNG_FILTER_NONE; break;
         case PNG_FILTER_VALUE_SUB:   png_ptr->do_filter=PNG_FILTER_SUB;  break;
         case PNG_FILTER_VALUE_UP:    png_ptr->do_filter=PNG_FILTER_UP;   break;
         case PNG_FILTER_VALUE_AVG:   png_ptr->do_filter=PNG_FILTER_AVG;  break;
         case PNG_FILTER_VALUE_PAETH: png_ptr->do_filter=PNG_FILTER_PAETH;break;
         default: png_ptr->do_filter = (png_byte)filters; break;
      }

      /* If we have allocated the row_buf, this means we have already started
       * with the image and we should have allocated all of the filter buffers
       * that have been selected.  If prev_row isn't already allocated, then
       * it is too late to start using the filters that need it, since we
       * will be missing the data in the previous row.  If an application
       * wants to start and stop using particular filters during compression,
       * it should start out with all of the filters, and then add and
       * remove them after the start of compression.
       */
      if (png_ptr->row_buf != NULL)
      {
         if (png_ptr->do_filter & PNG_FILTER_SUB && png_ptr->sub_row == NULL)
         {
            png_ptr->sub_row = (png_bytep)png_malloc(png_ptr,
              (png_ptr->rowbytes + 1));
            png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB;
         }

         if (png_ptr->do_filter & PNG_FILTER_UP && png_ptr->up_row == NULL)
         {
            if (png_ptr->prev_row == NULL)
            {
               png_warning(png_ptr, "Can't add Up filter after starting");
               png_ptr->do_filter &= ~PNG_FILTER_UP;
            }
            else
            {
               png_ptr->up_row = (png_bytep)png_malloc(png_ptr,
                  (png_ptr->rowbytes + 1));
               png_ptr->up_row[0] = PNG_FILTER_VALUE_UP;
            }
         }

         if (png_ptr->do_filter & PNG_FILTER_AVG && png_ptr->avg_row == NULL)
         {
            if (png_ptr->prev_row == NULL)
            {
               png_warning(png_ptr, "Can't add Average filter after starting");
               png_ptr->do_filter &= ~PNG_FILTER_AVG;
            }
            else
            {
               png_ptr->avg_row = (png_bytep)png_malloc(png_ptr,
                  (png_ptr->rowbytes + 1));
               png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG;
            }
         }

         if (png_ptr->do_filter & PNG_FILTER_PAETH &&
             png_ptr->paeth_row == NULL)
         {
            if (png_ptr->prev_row == NULL)
            {
               png_warning(png_ptr, "Can't add Paeth filter after starting");
               png_ptr->do_filter &= ~PNG_FILTER_PAETH;
            }
            else
            {
               png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr,
                  (png_ptr->rowbytes + 1));
               png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH;
            }
         }

         if (png_ptr->do_filter == PNG_NO_FILTERS)
            png_ptr->do_filter = PNG_FILTER_NONE;
      }
   }
   else
      png_error(png_ptr, "Unknown custom filter method");
}

void PNGAPI
png_free_data(png_structp png_ptr, png_infop info_ptr, png_uint_32 mask,
   int num)
{
   png_debug(1, "in png_free_data\n");
   if (png_ptr == NULL || info_ptr == NULL)
      return;

#if defined(PNG_TEXT_SUPPORTED)
/* free text item num or (if num == -1) all text items */
#ifdef PNG_FREE_ME_SUPPORTED
if ((mask & PNG_FREE_TEXT) & info_ptr->free_me)
#else
if (mask & PNG_FREE_TEXT)
#endif
{
   if (num != -1)
   {
     if (info_ptr->text && info_ptr->text[num].key)
     {
         png_free(png_ptr, info_ptr->text[num].key);
         info_ptr->text[num].key = NULL;
     }
   }
   else
   {
       int i;
       for (i = 0; i < info_ptr->num_text; i++)
           png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, i);
       png_free(png_ptr, info_ptr->text);
       info_ptr->text = NULL;
       info_ptr->num_text=0;
   }
}
#endif

#if defined(PNG_tRNS_SUPPORTED)
/* free any tRNS entry */
#ifdef PNG_FREE_ME_SUPPORTED
if ((mask & PNG_FREE_TRNS) & info_ptr->free_me)
#else
if ((mask & PNG_FREE_TRNS) && (png_ptr->flags & PNG_FLAG_FREE_TRNS))
#endif
{
    png_free(png_ptr, info_ptr->trans);
    info_ptr->valid &= ~PNG_INFO_tRNS;
#ifndef PNG_FREE_ME_SUPPORTED
    png_ptr->flags &= ~PNG_FLAG_FREE_TRNS;
#endif
    info_ptr->trans = NULL;
}
#endif

#if defined(PNG_sCAL_SUPPORTED)
/* free any sCAL entry */
#ifdef PNG_FREE_ME_SUPPORTED
if ((mask & PNG_FREE_SCAL) & info_ptr->free_me)
#else
if (mask & PNG_FREE_SCAL)
#endif
{
#if defined(PNG_FIXED_POINT_SUPPORTED) && !defined(PNG_FLOATING_POINT_SUPPORTED)
    png_free(png_ptr, info_ptr->scal_s_width);
    png_free(png_ptr, info_ptr->scal_s_height);
    info_ptr->scal_s_width = NULL;
    info_ptr->scal_s_height = NULL;
#endif
    info_ptr->valid &= ~PNG_INFO_sCAL;
}
#endif

#if defined(PNG_pCAL_SUPPORTED)
/* free any pCAL entry */
#ifdef PNG_FREE_ME_SUPPORTED
if ((mask & PNG_FREE_PCAL) & info_ptr->free_me)
#else
if (mask & PNG_FREE_PCAL)
#endif
{
    png_free(png_ptr, info_ptr->pcal_purpose);
    png_free(png_ptr, info_ptr->pcal_units);
    info_ptr->pcal_purpose = NULL;
    info_ptr->pcal_units = NULL;
    if (info_ptr->pcal_params != NULL)
    {
        int i;
        for (i = 0; i < (int)info_ptr->pcal_nparams; i++)
        {
          png_free(png_ptr, info_ptr->pcal_params[i]);
          info_ptr->pcal_params[i]=NULL;
        }
        png_free(png_ptr, info_ptr->pcal_params);
        info_ptr->pcal_params = NULL;
    }
    info_ptr->valid &= ~PNG_INFO_pCAL;
}
#endif

#if defined(PNG_iCCP_SUPPORTED)
/* free any iCCP entry */
//.........这里部分代码省略.........

/* Test one file */
int
test_one_file(PNG_CONST char *inname, PNG_CONST char *outname)
{
   static png_FILE_p fpin;
   static png_FILE_p fpout;  /* "static" prevents setjmp corruption */
   png_structp read_ptr;
   png_infop read_info_ptr, end_info_ptr;
#ifdef PNG_WRITE_SUPPORTED
   png_structp write_ptr;
   png_infop write_info_ptr;
   png_infop write_end_info_ptr;
#else
   png_structp write_ptr = NULL;
   png_infop write_info_ptr = NULL;
   png_infop write_end_info_ptr = NULL;
#endif
   png_bytep row_buf;
   png_uint_32 y;
   png_uint_32 width, height;
   int num_pass, pass;
   int bit_depth, color_type;
#ifdef PNG_SETJMP_SUPPORTED
#ifdef USE_FAR_KEYWORD
   jmp_buf jmpbuf;
#endif
#endif

#if defined(_WIN32_WCE)
   TCHAR path[MAX_PATH];
#endif
   char inbuf[256], outbuf[256];

   row_buf = NULL;

#if defined(_WIN32_WCE)
   MultiByteToWideChar(CP_ACP, 0, inname, -1, path, MAX_PATH);
   if ((fpin = CreateFile(path, GENERIC_READ, 0, NULL, OPEN_EXISTING, 0, NULL)) == INVALID_HANDLE_VALUE)
#else
   if ((fpin = fopen(inname, "rb")) == NULL)
#endif
   {
      fprintf(STDERR, "Could not find input file %s\n", inname);
      return (1);
   }

#if defined(_WIN32_WCE)
   MultiByteToWideChar(CP_ACP, 0, outname, -1, path, MAX_PATH);
   if ((fpout = CreateFile(path, GENERIC_WRITE, 0, NULL, CREATE_ALWAYS, 0, NULL)) == INVALID_HANDLE_VALUE)
#else
   if ((fpout = fopen(outname, "wb")) == NULL)
#endif
   {
      fprintf(STDERR, "Could not open output file %s\n", outname);
      FCLOSE(fpin);
      return (1);
   }

   png_debug(0, "Allocating read and write structures\n");
#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
   read_ptr = png_create_read_struct_2(PNG_LIBPNG_VER_STRING, png_voidp_NULL,
      png_error_ptr_NULL, png_error_ptr_NULL, png_voidp_NULL,
      (png_malloc_ptr)png_debug_malloc, (png_free_ptr)png_debug_free);
#else
   read_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, png_voidp_NULL,
      png_error_ptr_NULL, png_error_ptr_NULL);
#endif
   png_set_error_fn(read_ptr, (png_voidp)inname, pngtest_error,
       pngtest_warning);
#ifdef PNG_WRITE_SUPPORTED
#if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
   write_ptr = png_create_write_struct_2(PNG_LIBPNG_VER_STRING, png_voidp_NULL,
      png_error_ptr_NULL, png_error_ptr_NULL, png_voidp_NULL,
      (png_malloc_ptr)png_debug_malloc, (png_free_ptr)png_debug_free);
#else
   write_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, png_voidp_NULL,
      png_error_ptr_NULL, png_error_ptr_NULL);
#endif
   png_set_error_fn(write_ptr, (png_voidp)inname, pngtest_error,
       pngtest_warning);
#endif
   png_debug(0, "Allocating read_info, write_info and end_info structures\n");
   read_info_ptr = png_create_info_struct(read_ptr);
   end_info_ptr = png_create_info_struct(read_ptr);
#ifdef PNG_WRITE_SUPPORTED
   write_info_ptr = png_create_info_struct(write_ptr);
   write_end_info_ptr = png_create_info_struct(write_ptr);
#endif

#ifdef PNG_SETJMP_SUPPORTED
   png_debug(0, "Setting jmpbuf for read struct\n");
#ifdef USE_FAR_KEYWORD
   if (setjmp(jmpbuf))
#else
   if (setjmp(png_jmpbuf(read_ptr)))
#endif
   {
      fprintf(STDERR, "%s -> %s: libpng read error\n", inname, outname);
      if (row_buf)
         png_free(read_ptr, row_buf);
//.........这里部分代码省略.........

void PNGAPI
png_read_init_3(png_structpp ptr_ptr, png_const_charp user_png_ver,
                png_size_t png_struct_size)
{
#ifdef PNG_SETJMP_SUPPORTED
    jmp_buf tmp_jmp;  /* to save current jump buffer */
#endif

    int i=0;

    png_structp png_ptr=*ptr_ptr;

    do
    {
        if(user_png_ver[i] != png_libpng_ver[i])
        {
#ifdef PNG_LEGACY_SUPPORTED
            png_ptr->flags |= PNG_FLAG_LIBRARY_MISMATCH;
#else
            png_ptr->warning_fn=NULL;
            png_warning(png_ptr,
                        "Application uses deprecated png_read_init() and should be recompiled.");
            break;
#endif
        }
    } while (png_libpng_ver[i++]);

    png_debug(1, "in png_read_init_3\n");

#ifdef PNG_SETJMP_SUPPORTED
    /* save jump buffer and error functions */
    png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf));
#endif

    if(sizeof(png_struct) > png_struct_size)
    {
        png_destroy_struct(png_ptr);
        *ptr_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG);
        png_ptr = *ptr_ptr;
    }

    /* reset all variables to 0 */
    png_memset(png_ptr, 0, sizeof (png_struct));

#ifdef PNG_SETJMP_SUPPORTED
    /* restore jump buffer */
    png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf));
#endif

    /* initialize zbuf - compression buffer */
    png_ptr->zbuf_size = PNG_ZBUF_SIZE;
    png_ptr->zbuf = (png_bytep)png_malloc(png_ptr,
                                          (png_uint_32)png_ptr->zbuf_size);
    png_ptr->zstream.zalloc = png_zalloc;
    png_ptr->zstream.zfree = png_zfree;
    png_ptr->zstream.opaque = (voidpf)png_ptr;

    switch (inflateInit(&png_ptr->zstream))
    {
    case Z_OK: /* Do nothing */
        break;
    case Z_MEM_ERROR:
    case Z_STREAM_ERROR:
        png_error(png_ptr, "zlib memory");
        break;
    case Z_VERSION_ERROR:
        png_error(png_ptr, "zlib version");
        break;
    default:
        png_error(png_ptr, "Unknown zlib error");
    }

    png_ptr->zstream.next_out = png_ptr->zbuf;
    png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size;

    png_set_read_fn(png_ptr, png_voidp_NULL, png_rw_ptr_NULL);
}

/* Read the information before the actual image data.  This has been
 * changed in v0.90 to allow reading a file that already has the magic
 * bytes read from the stream.  You can tell libpng how many bytes have
 * been read from the beginning of the stream (up to the maximum of 8)
 * via png_set_sig_bytes(), and we will only check the remaining bytes
 * here.  The application can then have access to the signature bytes we
 * read if it is determined that this isn't a valid PNG file.
 */
void PNGAPI
png_read_info(png_structp png_ptr, png_infop info_ptr)
{
    png_debug(1, "in png_read_info\n");
    /* If we haven't checked all of the PNG signature bytes, do so now. */
    if (png_ptr->sig_bytes < 8)
    {
        png_size_t num_checked = png_ptr->sig_bytes,
                   num_to_check = 8 - num_checked;

        png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
        png_ptr->sig_bytes = 8;

        if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
        {
            if (num_checked < 4 &&
                    png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
                png_error(png_ptr, "Not a PNG file");
            else
                png_error(png_ptr, "PNG file corrupted by ASCII conversion");
        }
        if (num_checked < 3)
            png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
    }

    for(;;)
    {
#ifdef PNG_USE_LOCAL_ARRAYS
        PNG_IHDR;
        PNG_IDAT;
        PNG_IEND;
        PNG_PLTE;
#if defined(PNG_READ_bKGD_SUPPORTED)
        PNG_bKGD;
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
        PNG_cHRM;
#endif
#if defined(PNG_READ_gAMA_SUPPORTED)
        PNG_gAMA;
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
        PNG_hIST;
#endif
#if defined(PNG_READ_iCCP_SUPPORTED)
        PNG_iCCP;
#endif
#if defined(PNG_READ_iTXt_SUPPORTED)
        PNG_iTXt;
#endif
#if defined(PNG_READ_oFFs_SUPPORTED)
        PNG_oFFs;
#endif
#if defined(PNG_READ_pCAL_SUPPORTED)
        PNG_pCAL;
#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
        PNG_pHYs;
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
        PNG_sBIT;
#endif
#if defined(PNG_READ_sCAL_SUPPORTED)
        PNG_sCAL;
#endif
#if defined(PNG_READ_sPLT_SUPPORTED)
        PNG_sPLT;
#endif
#if defined(PNG_READ_sRGB_SUPPORTED)
        PNG_sRGB;
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
        PNG_tEXt;
#endif
#if defined(PNG_READ_tIME_SUPPORTED)
        PNG_tIME;
#endif
#if defined(PNG_READ_tRNS_SUPPORTED)
        PNG_tRNS;
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
        PNG_zTXt;
#endif
#endif /* PNG_GLOBAL_ARRAYS */
        png_byte chunk_length[4];
        png_uint_32 length;

        png_read_data(png_ptr, chunk_length, 4);
        length = png_get_uint_31(png_ptr,chunk_length);

        png_reset_crc(png_ptr);
        png_crc_read(png_ptr, png_ptr->chunk_name, 4);
//.........这里部分代码省略.........

/* turn on BGR-to-RGB mapping */
void
png_set_bgr(png_structp png_ptr)
{
   png_debug(1, "in png_set_bgr\n");
   png_ptr->transformations |= PNG_BGR;
}

/* Read the information before the actual image data.  This has been
 * changed in v0.90 to allow reading a file that already has the magic
 * bytes read from the stream.  You can tell libpng how many bytes have
 * been read from the beginning of the stream (up to the maximum of 8)
 * via png_set_sig_bytes(), and we will only check the remaining bytes
 * here.  The application can then have access to the signature bytes we
 * read if it is determined that this isn't a valid PNG file.
 */
void PNGAPI
png_read_info(png_structp png_ptr, png_infop info_ptr)
{
   png_debug(1, "in png_read_info");
 
   if (png_ptr == NULL || info_ptr == NULL)
      return;
 
   /* If we haven't checked all of the PNG signature bytes, do so now. */
   if (png_ptr->sig_bytes < 8)
   {
      png_size_t num_checked = png_ptr->sig_bytes,
                 num_to_check = 8 - num_checked;

#ifdef PNG_IO_STATE_SUPPORTED
      png_ptr->io_state = PNG_IO_READING | PNG_IO_SIGNATURE;
#endif

      png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check);
      png_ptr->sig_bytes = 8;

      if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check))
      {
         if (num_checked < 4 &&
             png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4))
            png_error(png_ptr, "Not a PNG file");
         else
            png_error(png_ptr, "PNG file corrupted by ASCII conversion");
      }
      if (num_checked < 3)
         png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
   }

   for (;;)
   {
      PNG_IHDR;
      PNG_IDAT;
      PNG_IEND;
      PNG_PLTE;
#ifdef PNG_READ_bKGD_SUPPORTED
      PNG_bKGD;
#endif
#ifdef PNG_READ_cHRM_SUPPORTED
      PNG_cHRM;
#endif
#ifdef PNG_READ_gAMA_SUPPORTED
      PNG_gAMA;
#endif
#ifdef PNG_READ_hIST_SUPPORTED
      PNG_hIST;
#endif
#ifdef PNG_READ_iCCP_SUPPORTED
      PNG_iCCP;
#endif
#ifdef PNG_READ_iTXt_SUPPORTED
      PNG_iTXt;
#endif
#ifdef PNG_READ_oFFs_SUPPORTED
      PNG_oFFs;
#endif
#ifdef PNG_READ_pCAL_SUPPORTED
      PNG_pCAL;
#endif
#ifdef PNG_READ_pHYs_SUPPORTED
      PNG_pHYs;
#endif
#ifdef PNG_READ_sBIT_SUPPORTED
      PNG_sBIT;
#endif
#ifdef PNG_READ_sCAL_SUPPORTED
      PNG_sCAL;
#endif
#ifdef PNG_READ_sPLT_SUPPORTED
      PNG_sPLT;
#endif
#ifdef PNG_READ_sRGB_SUPPORTED
      PNG_sRGB;
#endif
#ifdef PNG_READ_tEXt_SUPPORTED
      PNG_tEXt;
#endif
#ifdef PNG_READ_tIME_SUPPORTED
      PNG_tIME;
#endif
#ifdef PNG_READ_tRNS_SUPPORTED
      PNG_tRNS;
#endif
#ifdef PNG_READ_zTXt_SUPPORTED
      PNG_zTXt;
#endif
      png_uint_32 length = png_read_chunk_header(png_ptr);
      PNG_CONST png_bytep chunk_name = png_ptr->chunk_name;
//.........这里部分代码省略.........

void
png_set_invert_alpha(png_structp png_ptr)
{
   png_debug(1, "in png_set_invert_alpha\n");
   png_ptr->transformations |= PNG_INVERT_ALPHA;
}

void
png_set_invert_mono(png_structp png_ptr)
{
   png_debug(1, "in png_set_invert_mono\n");
   png_ptr->transformations |= PNG_INVERT_MONO;
}

void
png_set_swap_alpha(png_structp png_ptr)
{
   png_debug(1, "in png_set_swap_alpha\n");
   png_ptr->transformations |= PNG_SWAP_ALPHA;
}

void
png_init_filter_functions_neon(png_structp pp, unsigned int bpp)
{
   /* The switch statement is compiled in for ARM_NEON_API, the call to
    * png_have_neon is compiled in for ARM_NEON_CHECK.  If both are defined
    * the check is only performed if the API has not set the NEON option on
    * or off explicitly.  In this case the check controls what happens.
    *
    * If the CHECK is not compiled in and the option is UNSET the behavior prior
    * to 1.6.7 was to use the NEON code - this was a bug caused by having the
    * wrong order of the 'ON' and 'default' cases.  UNSET now defaults to OFF,
    * as documented in png.h
    */
   png_debug(1, "in png_init_filter_functions_neon");
#ifdef PNG_ARM_NEON_API_SUPPORTED
   switch ((pp->options >> PNG_ARM_NEON) & 3)
   {
      case PNG_OPTION_UNSET:
         /* Allow the run-time check to execute if it has been enabled -
          * thus both API and CHECK can be turned on.  If it isn't supported
          * this case will fall through to the 'default' below, which just
          * returns.
          */
#endif /* PNG_ARM_NEON_API_SUPPORTED */
#ifdef PNG_ARM_NEON_CHECK_SUPPORTED
         {
            static volatile sig_atomic_t no_neon = -1; /* not checked */

            if (no_neon < 0)
               no_neon = !png_have_neon(pp);

            if (no_neon)
               return;
         }
#ifdef PNG_ARM_NEON_API_SUPPORTED
         break;
#endif
#endif /* PNG_ARM_NEON_CHECK_SUPPORTED */

#ifdef PNG_ARM_NEON_API_SUPPORTED
      default: /* OFF or INVALID */
         return;

      case PNG_OPTION_ON:
         /* Option turned on */
         break;
   }
#endif

   /* IMPORTANT: any new external functions used here must be declared using
    * PNG_INTERNAL_FUNCTION in ../pngpriv.h.  This is required so that the
    * 'prefix' option to configure works:
    *
    *    ./configure --with-libpng-prefix=foobar_
    *
    * Verify you have got this right by running the above command, doing a build
    * and examining pngprefix.h; it must contain a #define for every external
    * function you add.  (Notice that this happens automatically for the
    * initialization function.)
    */
   pp->read_filter[PNG_FILTER_VALUE_UP-1] = png_read_filter_row_up_neon;

   if (bpp == 3)
   {
      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub3_neon;
      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg3_neon;
      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
         png_read_filter_row_paeth3_neon;
   }

   else if (bpp == 4)
   {
      pp->read_filter[PNG_FILTER_VALUE_SUB-1] = png_read_filter_row_sub4_neon;
      pp->read_filter[PNG_FILTER_VALUE_AVG-1] = png_read_filter_row_avg4_neon;
      pp->read_filter[PNG_FILTER_VALUE_PAETH-1] =
          png_read_filter_row_paeth4_neon;
   }
}

/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification,
 * and if invalid, correct the keyword rather than discarding the entire
 * chunk.  The PNG 1.0 specification requires keywords 1-79 characters in
 * length, forbids leading or trailing whitespace, multiple internal spaces,
 * and the non-break space (0x80) from ISO 8859-1.  Returns keyword length.
 *
 * The 'new_key' buffer must be 80 characters in size (for the keyword plus a
 * trailing '\0').  If this routine returns 0 then there was no keyword, or a
 * valid one could not be generated, and the caller must png_error.
 */
png_uint_32 /* PRIVATE */
png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key)
{
   png_const_charp orig_key = key;
   png_uint_32 key_len = 0;
   int bad_character = 0;
   int space = 1;

   png_debug(1, "in png_check_keyword");

   if (key == NULL)
   {
      *new_key = 0;
      return 0;
   }

   while (*key && key_len < 79)
   {
      png_byte ch = (png_byte)*key++;

      if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/))
         *new_key++ = ch, ++key_len, space = 0;

      else if (space == 0)
      {
         /* A space or an invalid character when one wasn't seen immediately
          * before; output just a space.
          */
         *new_key++ = 32, ++key_len, space = 1;

         /* If the character was not a space then it is invalid. */
         if (ch != 32)
            bad_character = ch;
      }

      else if (bad_character == 0)
         bad_character = ch; /* just skip it, record the first error */
   }

   if (key_len > 0 && space != 0) /* trailing space */
   {
      --key_len, --new_key;
      if (bad_character == 0)
         bad_character = 32;
   }

   /* Terminate the keyword */
   *new_key = 0;

   if (key_len == 0)
      return 0;

#ifdef PNG_WARNINGS_SUPPORTED
   /* Try to only output one warning per keyword: */
   if (*key != 0) /* keyword too long */
      png_warning(png_ptr, "keyword truncated");

   else if (bad_character != 0)
   {
      PNG_WARNING_PARAMETERS(p)

      png_warning_parameter(p, 1, orig_key);
      png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character);

      png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '[email protected]'");
   }
#endif /* WARNINGS */

   return key_len;
}

/* free all memory used by the read */
void PNGAPI
png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr,
                        png_infopp end_info_ptr_ptr)
{
    png_structp png_ptr = NULL;
    png_infop info_ptr = NULL, end_info_ptr = NULL;
#ifdef PNG_USER_MEM_SUPPORTED
    png_free_ptr free_fn = NULL;
    png_voidp mem_ptr = NULL;
#endif

    png_debug(1, "in png_destroy_read_struct\n");
    if (png_ptr_ptr != NULL)
        png_ptr = *png_ptr_ptr;

    if (info_ptr_ptr != NULL)
        info_ptr = *info_ptr_ptr;

    if (end_info_ptr_ptr != NULL)
        end_info_ptr = *end_info_ptr_ptr;

#ifdef PNG_USER_MEM_SUPPORTED
    free_fn = png_ptr->free_fn;
    mem_ptr = png_ptr->mem_ptr;
#endif

    png_read_destroy(png_ptr, info_ptr, end_info_ptr);

    if (info_ptr != NULL)
    {
#if defined(PNG_TEXT_SUPPORTED)
        png_free_data(png_ptr, info_ptr, PNG_FREE_TEXT, -1);
#endif

#ifdef PNG_USER_MEM_SUPPORTED
        png_destroy_struct_2((png_voidp)info_ptr, (png_free_ptr)free_fn,
                             (png_voidp)mem_ptr);
#else
        png_destroy_struct((png_voidp)info_ptr);
#endif
        *info_ptr_ptr = NULL;
    }

    if (end_info_ptr != NULL)
    {
#if defined(PNG_READ_TEXT_SUPPORTED)
        png_free_data(png_ptr, end_info_ptr, PNG_FREE_TEXT, -1);
#endif
#ifdef PNG_USER_MEM_SUPPORTED
        png_destroy_struct_2((png_voidp)end_info_ptr, (png_free_ptr)free_fn,
                             (png_voidp)mem_ptr);
#else
        png_destroy_struct((png_voidp)end_info_ptr);
#endif
        *end_info_ptr_ptr = NULL;
    }

    if (png_ptr != NULL)
    {
#ifdef PNG_USER_MEM_SUPPORTED
        png_destroy_struct_2((png_voidp)png_ptr, (png_free_ptr)free_fn,
                             (png_voidp)mem_ptr);
#else
        png_destroy_struct((png_voidp)png_ptr);
#endif
        *png_ptr_ptr = NULL;
    }
}