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/* pngpread.c - read a png file in push mode
libpng 1.0 beta 3 - version 0.89
For conditions of distribution and use, see copyright notice in png.h
Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
May 25, 1996
*/
#define PNG_INTERNAL
#include "png.h"
#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
void
png_process_data(png_structp png_ptr, png_infop info,
png_bytep buffer, png_uint_32 buffer_size)
{
png_push_restore_buffer(png_ptr, buffer, buffer_size);
while (png_ptr->buffer_size)
{
png_process_some_data(png_ptr, info);
}
}
void
png_process_some_data(png_structp png_ptr, png_infop info)
{
switch (png_ptr->process_mode)
{
case PNG_READ_SIG_MODE:
{
png_push_read_sig(png_ptr);
break;
}
case PNG_READ_CHUNK_MODE:
{
png_push_read_chunk(png_ptr, info);
break;
}
case PNG_READ_IDAT_MODE:
{
png_push_read_IDAT(png_ptr);
break;
}
case PNG_READ_PLTE_MODE:
{
png_push_read_PLTE(png_ptr, info);
break;
}
#if defined(PNG_READ_tEXt_SUPPORTED)
case PNG_READ_tEXt_MODE:
{
png_push_read_tEXt(png_ptr, info);
break;
}
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
case PNG_READ_zTXt_MODE:
{
png_push_read_zTXt(png_ptr, info);
break;
}
#endif
case PNG_READ_END_MODE:
{
png_push_read_end(png_ptr, info);
break;
}
case PNG_SKIP_MODE:
{
png_push_skip(png_ptr);
break;
}
default:
{
png_ptr->buffer_size = 0;
break;
}
}
}
void
png_push_read_sig(png_structp png_ptr)
{
png_byte sig[8];
if (png_ptr->buffer_size < 8)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_fill_buffer(png_ptr, sig, 8);
if (png_check_sig(sig, 8))
{
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
}
else
{
png_error(png_ptr, "Not a PNG file");
}
}
void
png_push_read_chunk(png_structp png_ptr, png_infop info)
{
if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER))
{
png_byte chunk_start[8];
if (png_ptr->buffer_size < 8)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_fill_buffer(png_ptr, chunk_start, 8);
png_ptr->push_length = png_get_uint_32(chunk_start);
png_memcpy(png_ptr->push_chunk_name, (png_voidp)(chunk_start + 4), 4);
png_ptr->flags |= PNG_FLAG_HAVE_CHUNK_HEADER;
png_reset_crc(png_ptr);
png_calculate_crc(png_ptr, chunk_start + 4, 4);
}
if (!png_memcmp(png_ptr->push_chunk_name, png_IHDR, 4))
{
if (png_ptr->mode != PNG_BEFORE_IHDR)
png_error(png_ptr, "Out of place IHDR");
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
png_handle_IHDR(png_ptr, info, png_ptr->push_length);
png_push_check_crc(png_ptr);
png_ptr->mode = PNG_HAVE_IHDR;
}
else if (!png_memcmp(png_ptr->push_chunk_name, png_PLTE, 4))
{
if (png_ptr->mode != PNG_HAVE_IHDR)
png_error(png_ptr, "Missing IHDR");
#if !defined(PNG_READ_OPT_PLTE_SUPPORTED)
if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)
png_push_crc_skip(png_ptr, length);
else
#else
{
png_push_handle_PLTE(png_ptr, png_ptr->push_length);
}
#endif
png_ptr->mode = PNG_HAVE_PLTE;
}
else if (!png_memcmp(png_ptr->push_chunk_name, png_IDAT, 4))
{
png_ptr->idat_size = png_ptr->push_length;
png_ptr->mode = PNG_HAVE_IDAT;
png_ptr->process_mode = PNG_READ_IDAT_MODE;
png_push_have_info(png_ptr, info);
png_ptr->zstream->avail_out = (uInt)png_ptr->irowbytes;
png_ptr->zstream->next_out = png_ptr->row_buf;
return;
}
else if (!png_memcmp(png_ptr->push_chunk_name, png_IEND, 4))
{
png_error(png_ptr, "No image in file");
}
#if defined(PNG_READ_gAMA_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_gAMA, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
if (png_ptr->mode != PNG_HAVE_IHDR)
png_error(png_ptr, "Out of place gAMA");
png_handle_gAMA(png_ptr, info, png_ptr->push_length);
png_push_check_crc(png_ptr);
}
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_sBIT, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
if (png_ptr->mode != PNG_HAVE_IHDR)
png_error(png_ptr, "Out of place sBIT");
png_handle_sBIT(png_ptr, info, png_ptr->push_length);
png_push_check_crc(png_ptr);
}
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_cHRM, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
if (png_ptr->mode != PNG_HAVE_IHDR)
png_error(png_ptr, "Out of place cHRM");
png_handle_cHRM(png_ptr, info, png_ptr->push_length);
png_push_check_crc(png_ptr);
}
#endif
#if defined(PNG_READ_tRNS_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_tRNS, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
if (png_ptr->mode != PNG_HAVE_IHDR &&
png_ptr->mode != PNG_HAVE_PLTE)
png_error(png_ptr, "Out of place tRNS");
png_handle_tRNS(png_ptr, info, png_ptr->push_length);
png_push_check_crc(png_ptr);
}
#endif
#if defined(PNG_READ_bKGD_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_bKGD, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
if (png_ptr->mode != PNG_HAVE_IHDR &&
png_ptr->mode != PNG_HAVE_PLTE)
png_error(png_ptr, "Out of place bKGD");
png_handle_bKGD(png_ptr, info, png_ptr->push_length);
png_push_check_crc(png_ptr);
}
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_hIST, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
if (png_ptr->mode != PNG_HAVE_PLTE)
png_error(png_ptr, "Out of place hIST");
png_handle_hIST(png_ptr, info, png_ptr->push_length);
png_push_check_crc(png_ptr);
}
#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_pHYs, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
if (png_ptr->mode != PNG_HAVE_IHDR &&
png_ptr->mode != PNG_HAVE_PLTE)
png_error(png_ptr, "Out of place pHYs");
png_handle_pHYs(png_ptr, info, png_ptr->push_length);
png_push_check_crc(png_ptr);
}
#endif
#if defined(PNG_READ_oFFs_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_oFFs, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
if (png_ptr->mode != PNG_HAVE_IHDR &&
png_ptr->mode != PNG_HAVE_PLTE)
png_error(png_ptr, "Out of place oFFs");
png_handle_oFFs(png_ptr, info, png_ptr->push_length);
png_push_check_crc(png_ptr);
}
#endif
#if defined(PNG_READ_tIME_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_tIME, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
if (png_ptr->mode == PNG_BEFORE_IHDR ||
png_ptr->mode == PNG_AFTER_IEND)
png_error(png_ptr, "Out of place tIME");
png_handle_tIME(png_ptr, info, png_ptr->push_length);
png_push_check_crc(png_ptr);
}
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_tEXt, 4))
{
if (png_ptr->mode == PNG_BEFORE_IHDR ||
png_ptr->mode == PNG_AFTER_IEND)
png_error(png_ptr, "Out of place tEXt");
png_push_handle_tEXt(png_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_zTXt, 4))
{
if (png_ptr->mode == PNG_BEFORE_IHDR ||
png_ptr->mode == PNG_AFTER_IEND)
png_error(png_ptr, "Out of place zTXt");
png_push_handle_zTXt(png_ptr, png_ptr->push_length);
}
#endif
else
{
if (png_ptr->push_chunk_name[0] <41 || png_ptr->push_chunk_name[0]> 122 ||
(png_ptr->push_chunk_name[0]>90 && png_ptr->push_chunk_name[0]< 97) ||
png_ptr->push_chunk_name[1] <41 || png_ptr->push_chunk_name[1]> 122 ||
(png_ptr->push_chunk_name[1]>90 && png_ptr->push_chunk_name[1]< 97) ||
png_ptr->push_chunk_name[2] <41 || png_ptr->push_chunk_name[2]> 122 ||
(png_ptr->push_chunk_name[2]>90 && png_ptr->push_chunk_name[2]< 97) ||
png_ptr->push_chunk_name[3] <41 || png_ptr->push_chunk_name[3]> 122 ||
(png_ptr->push_chunk_name[3]>90 && png_ptr->push_chunk_name[3]< 97))
{
char msg[200];
sprintf(msg, "Invalid chunk type 0x%02X 0x%02X 0x%02X 0x%02X",
png_ptr->push_chunk_name[0], png_ptr->push_chunk_name[1],
png_ptr->push_chunk_name[2], png_ptr->push_chunk_name[3]);
png_error(png_ptr, msg);
}
if ((png_ptr->push_chunk_name[0] & 0x20) == 0)
{
char msg[200];
sprintf(msg, "Unknown critical chunk %c%c%c%c",
png_ptr->push_chunk_name[0], png_ptr->push_chunk_name[1],
png_ptr->push_chunk_name[2], png_ptr->push_chunk_name[3]);
png_error(png_ptr, msg);
}
png_push_crc_skip(png_ptr, png_ptr->push_length);
}
png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER;
}
void
png_push_check_crc(png_structp png_ptr)
{
png_byte crc_buf[4];
png_uint_32 crc;
png_push_fill_buffer(png_ptr, crc_buf, 4);
crc = png_get_uint_32(crc_buf);
if (((crc ^ 0xffffffffL) & 0xffffffffL) !=
(png_ptr->crc & 0xffffffffL))
png_error(png_ptr, "Bad CRC value");
}
void
png_push_crc_skip(png_structp png_ptr, png_uint_32 length)
{
png_ptr->process_mode = PNG_SKIP_MODE;
png_ptr->skip_length = length;
}
void
png_push_skip(png_structp png_ptr)
{
if (png_ptr->skip_length && png_ptr->save_buffer_size)
{
png_uint_32 save_size;
if (png_ptr->skip_length < png_ptr->save_buffer_size)
save_size = png_ptr->skip_length;
else
save_size = png_ptr->save_buffer_size;
png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
png_ptr->skip_length -= save_size;
png_ptr->buffer_size -= save_size;
png_ptr->save_buffer_size -= save_size;
png_ptr->save_buffer_ptr += (png_size_t)save_size;
}
if (png_ptr->skip_length && png_ptr->current_buffer_size)
{
png_uint_32 save_size;
if (png_ptr->skip_length < png_ptr->current_buffer_size)
save_size = png_ptr->skip_length;
else
save_size = png_ptr->current_buffer_size;
png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
png_ptr->skip_length -= save_size;
png_ptr->buffer_size -= save_size;
png_ptr->current_buffer_size -= save_size;
png_ptr->current_buffer_ptr += (png_size_t)save_size;
}
if (!png_ptr->skip_length)
{
if (png_ptr->buffer_size < 4)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_check_crc(png_ptr);
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
}
}
void
png_push_fill_buffer(png_structp png_ptr, png_bytep buffer,
png_uint_32 length)
{
png_bytep ptr;
ptr = buffer;
if (png_ptr->save_buffer_size)
{
png_uint_32 save_size;
if (length < png_ptr->save_buffer_size)
save_size = length;
else
save_size = png_ptr->save_buffer_size;
png_memcpy(ptr, png_ptr->save_buffer_ptr, (png_size_t)save_size);
length -= save_size;
ptr += (png_size_t)save_size;
png_ptr->buffer_size -= save_size;
png_ptr->save_buffer_size -= save_size;
png_ptr->save_buffer_ptr += (png_size_t)save_size;
}
if (length && png_ptr->current_buffer_size)
{
png_uint_32 save_size;
if (length < png_ptr->current_buffer_size)
save_size = length;
else
save_size = png_ptr->current_buffer_size;
png_memcpy(ptr, png_ptr->current_buffer_ptr, (png_size_t)save_size);
png_ptr->buffer_size -= save_size;
png_ptr->current_buffer_size -= save_size;
png_ptr->current_buffer_ptr += (png_size_t)save_size;
}
}
void
png_push_save_buffer(png_structp png_ptr)
{
if (png_ptr->save_buffer_size)
{
if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
{
int i;
png_bytep sp;
png_bytep dp;
for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
i < png_ptr->save_buffer_size;
i++, sp++, dp++)
{
*dp = *sp;
}
}
}
if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
png_ptr->save_buffer_max)
{
int new_max;
png_bytep old_buffer;
new_max = (int)(png_ptr->save_buffer_size +
png_ptr->current_buffer_size + 256);
old_buffer = png_ptr->save_buffer;
png_ptr->save_buffer = (png_bytep)
png_large_malloc(png_ptr, new_max);
png_memcpy(png_ptr->save_buffer, old_buffer,
(png_size_t)png_ptr->save_buffer_size);
png_large_free(png_ptr, old_buffer);
png_ptr->save_buffer_max = new_max;
}
if (png_ptr->current_buffer_size)
{
png_memcpy(png_ptr->save_buffer +
(png_size_t)png_ptr->save_buffer_size,
png_ptr->current_buffer_ptr,
(png_size_t)png_ptr->current_buffer_size);
png_ptr->save_buffer_size += png_ptr->current_buffer_size;
png_ptr->current_buffer_size = 0;
}
png_ptr->save_buffer_ptr = png_ptr->save_buffer;
png_ptr->buffer_size = 0;
}
void
png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
png_uint_32 buffer_length)
{
png_ptr->current_buffer = buffer;
png_ptr->current_buffer_size = buffer_length;
png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size;
png_ptr->current_buffer_ptr = png_ptr->current_buffer;
}
void
png_push_read_IDAT(png_structp png_ptr)
{
if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER))
{
png_byte chunk_start[8];
if (png_ptr->buffer_size < 8)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_fill_buffer(png_ptr, chunk_start, 8);
png_ptr->push_length = png_get_uint_32(chunk_start);
png_memcpy(png_ptr->push_chunk_name,
(png_voidp)(chunk_start + 4), 4);
png_ptr->flags |= PNG_FLAG_HAVE_CHUNK_HEADER;
png_reset_crc(png_ptr);
png_calculate_crc(png_ptr, chunk_start + 4, 4);
if (png_memcmp(png_ptr->push_chunk_name, png_IDAT, 4))
{
png_ptr->process_mode = PNG_READ_END_MODE;
if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
png_error(png_ptr, "Not enough compressed data");
return;
}
png_ptr->idat_size = png_ptr->push_length;
}
if (png_ptr->idat_size && png_ptr->save_buffer_size)
{
png_uint_32 save_size;
if (png_ptr->idat_size < png_ptr->save_buffer_size)
save_size = png_ptr->idat_size;
else
save_size = png_ptr->save_buffer_size;
png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size);
png_ptr->idat_size -= save_size;
png_ptr->buffer_size -= save_size;
png_ptr->save_buffer_size -= save_size;
png_ptr->save_buffer_ptr += (png_size_t)save_size;
}
if (png_ptr->idat_size && png_ptr->current_buffer_size)
{
png_uint_32 save_size;
if (png_ptr->idat_size < png_ptr->current_buffer_size)
save_size = png_ptr->idat_size;
else
save_size = png_ptr->current_buffer_size;
png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size);
png_ptr->idat_size -= save_size;
png_ptr->buffer_size -= save_size;
png_ptr->current_buffer_size -= save_size;
png_ptr->current_buffer_ptr += (png_size_t)save_size;
}
if (!png_ptr->idat_size)
{
if (png_ptr->buffer_size < 4)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_check_crc(png_ptr);
png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER;
}
}
void
png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
png_uint_32 buffer_length)
{
int ret;
if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length)
png_error(png_ptr, "Extra compression data");
png_ptr->zstream->next_in = buffer;
png_ptr->zstream->avail_in = (uInt)buffer_length;
do
{
ret = inflate(png_ptr->zstream, Z_PARTIAL_FLUSH);
if (ret == Z_STREAM_END)
{
if (png_ptr->zstream->avail_in)
png_error(png_ptr, "Extra compressed data");
if (!png_ptr->zstream->avail_out)
{
png_push_process_row(png_ptr);
}
png_ptr->mode = PNG_AT_LAST_IDAT;
png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
break;
}
if (ret != Z_OK)
png_error(png_ptr, "Decompression Error");
if (!(png_ptr->zstream->avail_out))
{
png_push_process_row(png_ptr);
png_ptr->zstream->avail_out = (uInt)png_ptr->irowbytes;
png_ptr->zstream->next_out = png_ptr->row_buf;
}
} while (png_ptr->zstream->avail_in);
}
void
png_push_process_row(png_structp png_ptr)
{
png_ptr->row_info.color_type = png_ptr->color_type;
png_ptr->row_info.width = png_ptr->iwidth;
png_ptr->row_info.channels = png_ptr->channels;
png_ptr->row_info.bit_depth = png_ptr->bit_depth;
png_ptr->row_info.pixel_depth = png_ptr->pixel_depth;
png_ptr->row_info.rowbytes = ((png_ptr->row_info.width *
(png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3);
png_read_filter_row(png_ptr, &(png_ptr->row_info),
png_ptr->row_buf + 1, png_ptr->prev_row + 1,
(int)(png_ptr->row_buf[0]));
png_memcpy(png_ptr->prev_row, png_ptr->row_buf, (png_size_t)png_ptr->rowbytes + 1);
if (png_ptr->transformations)
png_do_read_transformations(png_ptr);
#if defined(PNG_READ_INTERLACING_SUPPORTED)
/* blow up interlaced rows to full size */
if (png_ptr->interlaced &&
(png_ptr->transformations & PNG_INTERLACE))
{
if (png_ptr->pass < 6)
png_do_read_interlace(&(png_ptr->row_info),
png_ptr->row_buf + 1, png_ptr->pass);
switch (png_ptr->pass)
{
case 0:
{
int i;
for (i = 0; i < 8 && png_ptr->pass == 0; i++)
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
}
break;
}
case 1:
{
int i;
for (i = 0; i < 8 && png_ptr->pass == 1; i++)
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
}
if (png_ptr->pass == 2)
{
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
{
png_push_have_row(png_ptr, NULL);
png_read_push_finish_row(png_ptr);
}
}
break;
}
case 2:
{
int i;
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
}
for (i = 0; i < 4 && png_ptr->pass == 2; i++)
{
png_push_have_row(png_ptr, NULL);
png_read_push_finish_row(png_ptr);
}
break;
}
case 3:
{
int i;
for (i = 0; i < 4 && png_ptr->pass == 3; i++)
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
}
if (png_ptr->pass == 4)
{
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
{
png_push_have_row(png_ptr, NULL);
png_read_push_finish_row(png_ptr);
}
}
break;
}
case 4:
{
int i;
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
}
for (i = 0; i < 2 && png_ptr->pass == 4; i++)
{
png_push_have_row(png_ptr, NULL);
png_read_push_finish_row(png_ptr);
}
break;
}
case 5:
{
int i;
for (i = 0; i < 2 && png_ptr->pass == 5; i++)
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
}
if (png_ptr->pass == 6)
{
png_push_have_row(png_ptr, NULL);
png_read_push_finish_row(png_ptr);
}
break;
}
case 6:
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
if (png_ptr->pass != 6)
break;
png_push_have_row(png_ptr, NULL);
png_read_push_finish_row(png_ptr);
}
}
}
else
#endif
{
png_push_have_row(png_ptr, png_ptr->row_buf + 1);
png_read_push_finish_row(png_ptr);
}
}
void
png_read_push_finish_row(png_structp png_ptr)
{
png_ptr->row_number++;
if (png_ptr->row_number < png_ptr->num_rows)
return;
if (png_ptr->interlaced)
{
png_ptr->row_number = 0;
png_memset(png_ptr->prev_row, 0, (png_size_t)png_ptr->rowbytes + 1);
do
{
png_ptr->pass++;
if (png_ptr->pass >= 7)
break;
png_ptr->iwidth = (png_ptr->width +
png_pass_inc[png_ptr->pass] - 1 -
png_pass_start[png_ptr->pass]) /
png_pass_inc[png_ptr->pass];
png_ptr->irowbytes = ((png_ptr->iwidth *
png_ptr->pixel_depth + 7) >> 3) + 1;
if (!(png_ptr->transformations & PNG_INTERLACE))
{
png_ptr->num_rows = (png_ptr->height +
png_pass_yinc[png_ptr->pass] - 1 -
png_pass_ystart[png_ptr->pass]) /
png_pass_yinc[png_ptr->pass];
if (!(png_ptr->num_rows))
continue;
}
if (png_ptr->transformations & PNG_INTERLACE)
break;
} while (png_ptr->iwidth == 0);
}
}
void
png_push_handle_PLTE(png_structp png_ptr, png_uint_32 length)
{
if (length % 3)
png_error(png_ptr, "Invalid palette chunk");
png_ptr->num_palette = (png_uint_16)(length / 3);
png_ptr->cur_palette = 0;
png_ptr->palette = (png_colorp)png_large_malloc(png_ptr,
png_ptr->num_palette * sizeof (png_color));
png_ptr->process_mode = PNG_READ_PLTE_MODE;
}
void
png_push_read_PLTE(png_structp png_ptr, png_infop info)
{
while (png_ptr->cur_palette < png_ptr->num_palette &&
png_ptr->buffer_size >= 3)
{
png_byte buf[3];
png_push_fill_buffer(png_ptr, buf, 3);
png_calculate_crc(png_ptr, buf, 3);
/* don't depend upon png_color being any order */
png_ptr->palette[png_ptr->cur_palette].red = buf[0];
png_ptr->palette[png_ptr->cur_palette].green = buf[1];
png_ptr->palette[png_ptr->cur_palette].blue = buf[2];
png_ptr->cur_palette++;
}
if (png_ptr->cur_palette == png_ptr->num_palette &&
png_ptr->buffer_size >= 4)
{
png_push_check_crc(png_ptr);
png_read_PLTE(png_ptr, info, png_ptr->palette, png_ptr->num_palette);
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
}
else
{
png_push_save_buffer(png_ptr);
}
}
#if defined(PNG_READ_tEXt_SUPPORTED)
void
png_push_handle_tEXt(png_structp png_ptr, png_uint_32 length)
{
png_ptr->current_text = (png_charp)png_large_malloc(png_ptr, length + 1);
png_ptr->current_text[(png_size_t)length] = '\0';
png_ptr->current_text_ptr = png_ptr->current_text;
png_ptr->current_text_size = length;
png_ptr->current_text_left = length;
png_ptr->process_mode = PNG_READ_tEXt_MODE;
}
void
png_push_read_tEXt(png_structp png_ptr, png_infop info)
{
if (png_ptr->buffer_size && png_ptr->current_text_left)
{
png_uint_32 text_size;
if (png_ptr->buffer_size < png_ptr->current_text_left)
text_size = png_ptr->buffer_size;
else
text_size = png_ptr->current_text_left;
png_push_fill_buffer(png_ptr, (png_bytep)png_ptr->current_text_ptr,
text_size);
png_calculate_crc(png_ptr, (png_bytep)png_ptr->current_text_ptr,
text_size);
png_ptr->current_text_left -= text_size;
png_ptr->current_text_ptr += (png_size_t)text_size;
}
if (!(png_ptr->current_text_left))
{
png_charp text;
png_charp key;
if (png_ptr->buffer_size < 4)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_check_crc(png_ptr);
key = png_ptr->current_text;
png_ptr->current_text = 0;
for (text = key; *text; text++)
/* empty loop */ ;
if (text != key + (png_size_t)png_ptr->current_text_size)
text++;
png_read_tEXt(png_ptr, info, key, text,
png_ptr->current_text_size - (text - key));
if (png_ptr->mode == PNG_AT_LAST_IDAT ||
png_ptr->mode == PNG_AFTER_IDAT)
{
png_ptr->process_mode = PNG_READ_END_MODE;
}
else
{
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
}
}
}
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
void
png_push_handle_zTXt(png_structp png_ptr,
png_uint_32 length)
{
png_ptr->current_text = (png_charp)png_large_malloc(png_ptr, length + 1);
png_ptr->current_text[(png_size_t)length] = '\0';
png_ptr->current_text_ptr = png_ptr->current_text;
png_ptr->current_text_size = length;
png_ptr->current_text_left = length;
png_ptr->process_mode = PNG_READ_zTXt_MODE;
}
void
png_push_read_zTXt(png_structp png_ptr, png_infop info)
{
if (png_ptr->buffer_size && png_ptr->current_text_left)
{
png_uint_32 text_size;
if (png_ptr->buffer_size < png_ptr->current_text_left)
text_size = png_ptr->buffer_size;
else
text_size = png_ptr->current_text_left;
png_push_fill_buffer(png_ptr, (png_bytep)png_ptr->current_text_ptr,
text_size);
png_calculate_crc(png_ptr, (png_bytep)png_ptr->current_text_ptr,
text_size);
png_ptr->current_text_left -= text_size;
png_ptr->current_text_ptr += (png_size_t)text_size;
}
if (!(png_ptr->current_text_left))
{
png_charp text;
png_charp key;
int ret;
png_uint_32 text_size, key_size;
if (png_ptr->buffer_size < 4)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_check_crc(png_ptr);
key = png_ptr->current_text;
png_ptr->current_text = 0;
for (text = key; *text; text++)
/* empty loop */ ;
/* zTXt can't have zero text */
if (text == key + (png_size_t)png_ptr->current_text_size)
{
png_large_free(png_ptr, key);
return;
}
text++;
if (*text) /* check compression byte */
{
png_large_free(png_ptr, key);
return;
}
text++;
png_ptr->zstream->next_in = (png_bytep )text;
png_ptr->zstream->avail_in = (uInt)(png_ptr->current_text_size -
(text - key));
png_ptr->zstream->next_out = png_ptr->zbuf;
png_ptr->zstream->avail_out = (png_size_t)png_ptr->zbuf_size;
key_size = text - key;
text_size = 0;
text = NULL;
ret = Z_STREAM_END;
while (png_ptr->zstream->avail_in)
{
ret = inflate(png_ptr->zstream, Z_PARTIAL_FLUSH);
if (ret != Z_OK && ret != Z_STREAM_END)
{
inflateReset(png_ptr->zstream);
png_ptr->zstream->avail_in = 0;
png_large_free(png_ptr, key);
png_large_free(png_ptr, text);
return;
}
if (!png_ptr->zstream->avail_out || ret == Z_STREAM_END)
{
if (!text)
{
text = (png_charp)png_large_malloc(png_ptr,
png_ptr->zbuf_size - png_ptr->zstream->avail_out +
key_size + 1);
png_memcpy(text + (png_size_t)key_size, png_ptr->zbuf,
(png_size_t)(png_ptr->zbuf_size - png_ptr->zstream->avail_out));
png_memcpy(text, key, (png_size_t)key_size);
text_size = key_size + (png_size_t)png_ptr->zbuf_size -
png_ptr->zstream->avail_out;
*(text + (png_size_t)text_size) = '\0';
}
else
{
png_charp tmp;
tmp = text;
text = png_large_malloc(png_ptr, text_size +
png_ptr->zbuf_size - png_ptr->zstream->avail_out + 1);
png_memcpy(text, tmp, (png_size_t)text_size);
png_large_free(png_ptr, tmp);
png_memcpy(text + (png_size_t)text_size, png_ptr->zbuf,
(png_size_t)(png_ptr->zbuf_size - png_ptr->zstream->avail_out));
text_size += png_ptr->zbuf_size - png_ptr->zstream->avail_out;
*(text + (png_size_t)text_size) = '\0';
}
if (ret != Z_STREAM_END)
{
png_ptr->zstream->next_out = png_ptr->zbuf;
png_ptr->zstream->avail_out = (uInt)png_ptr->zbuf_size;
}
}
else
{
break;
}
if (ret == Z_STREAM_END)
break;
}
inflateReset(png_ptr->zstream);
png_ptr->zstream->avail_in = 0;
if (ret != Z_STREAM_END)
{
png_large_free(png_ptr, key);
png_large_free(png_ptr, text);
return;
}
png_large_free(png_ptr, key);
key = text;
text += (png_size_t)key_size;
text_size -= key_size;
png_read_zTXt(png_ptr, info, key, text, text_size, 0);
if (png_ptr->mode == PNG_AT_LAST_IDAT ||
png_ptr->mode == PNG_AFTER_IDAT)
{
png_ptr->process_mode = PNG_READ_END_MODE;
}
else
{
png_ptr->process_mode = PNG_READ_CHUNK_MODE;
}
}
}
#endif
void
png_push_have_info(png_structp png_ptr, png_infop info)
{
if (png_ptr->info_fn)
(*(png_ptr->info_fn))(png_ptr, info);
}
void
png_push_have_end(png_structp png_ptr, png_infop info)
{
if (png_ptr->end_fn)
(*(png_ptr->end_fn))(png_ptr, info);
}
void
png_push_have_row(png_structp png_ptr, png_bytep row)
{
if (png_ptr->row_fn)
(*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
(int)png_ptr->pass);
}
png_voidp
png_get_progressive_ptr(png_structp png_ptr)
{
return png_ptr->io_ptr;
}
void
png_push_read_end(png_structp png_ptr, png_infop info)
{
if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER))
{
png_byte chunk_start[8];
if (png_ptr->buffer_size < 8)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_fill_buffer(png_ptr, chunk_start, 8);
png_ptr->push_length = png_get_uint_32(chunk_start);
png_memcpy(png_ptr->push_chunk_name, (png_voidp)(chunk_start + 4), 4);
png_ptr->flags |= PNG_FLAG_HAVE_CHUNK_HEADER;
png_reset_crc(png_ptr);
png_calculate_crc(png_ptr, chunk_start + 4, 4);
}
if (!png_memcmp(png_ptr->push_chunk_name, png_IHDR, 4))
{
png_error(png_ptr, "Invalid IHDR after IDAT");
}
else if (!png_memcmp(png_ptr->push_chunk_name, png_PLTE, 4))
{
png_error(png_ptr, "Invalid PLTE after IDAT");
}
else if (!png_memcmp(png_ptr->push_chunk_name, png_IDAT, 4))
{
if (png_ptr->push_length > 0 || png_ptr->mode != PNG_AT_LAST_IDAT)
png_error(png_ptr, "Too many IDAT's found");
}
else if (!png_memcmp(png_ptr->push_chunk_name, png_IEND, 4))
{
if (png_ptr->push_length)
png_error(png_ptr, "Invalid IEND chunk");
if (png_ptr->buffer_size < 4)
{
png_push_save_buffer(png_ptr);
return;
}
png_push_check_crc(png_ptr);
png_ptr->mode = PNG_AFTER_IEND;
png_ptr->process_mode = PNG_READ_DONE_MODE;
png_push_have_end(png_ptr, info);
}
#if defined(PNG_READ_gAMA_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_gAMA, 4))
{
png_error(png_ptr, "Invalid gAMA after IDAT");
}
#endif
#if defined(PNG_READ_sBIT_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_sBIT, 4))
{
png_error(png_ptr, "Invalid sBIT after IDAT");
}
#endif
#if defined(PNG_READ_cHRM_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_cHRM, 4))
{
png_error(png_ptr, "Invalid cHRM after IDAT");
}
#endif
#if defined(PNG_READ_tRNS_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_tRNS, 4))
{
png_error(png_ptr, "Invalid tRNS after IDAT");
}
#endif
#if defined(PNG_READ_bKGD_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_bKGD, 4))
{
png_error(png_ptr, "Invalid bKGD after IDAT");
}
#endif
#if defined(PNG_READ_hIST_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_hIST, 4))
{
png_error(png_ptr, "Invalid hIST after IDAT");
}
#endif
#if defined(PNG_READ_pHYs_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_pHYs, 4))
{
png_error(png_ptr, "Invalid pHYs after IDAT");
}
#endif
#if defined(PNG_READ_oFFs_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_oFFs, 4))
{
png_error(png_ptr, "Invalid oFFs after IDAT");
}
#endif
#if defined(PNG_READ_tIME_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_tIME, 4))
{
if (png_ptr->push_length + 4 > png_ptr->buffer_size)
{
png_push_save_buffer(png_ptr);
return;
}
if (png_ptr->mode == PNG_BEFORE_IHDR ||
png_ptr->mode == PNG_AFTER_IEND)
png_error(png_ptr, "Out of place tIME");
png_handle_tIME(png_ptr, info, png_ptr->push_length);
png_push_check_crc(png_ptr);
}
#endif
#if defined(PNG_READ_tEXt_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_tEXt, 4))
{
if (png_ptr->mode == PNG_BEFORE_IHDR ||
png_ptr->mode == PNG_AFTER_IEND)
png_error(png_ptr, "Out of place tEXt");
png_push_handle_tEXt(png_ptr, png_ptr->push_length);
}
#endif
#if defined(PNG_READ_zTXt_SUPPORTED)
else if (!png_memcmp(png_ptr->push_chunk_name, png_zTXt, 4))
{
if (png_ptr->mode == PNG_BEFORE_IHDR ||
png_ptr->mode == PNG_AFTER_IEND)
png_error(png_ptr, "Out of place zTXt");
png_push_handle_zTXt(png_ptr, png_ptr->push_length);
}
#endif
else
{
if (png_ptr->push_chunk_name[0] <41 || png_ptr->push_chunk_name[0]> 122 ||
(png_ptr->push_chunk_name[0]>90 && png_ptr->push_chunk_name[0]< 97) ||
png_ptr->push_chunk_name[1] <41 || png_ptr->push_chunk_name[1]> 122 ||
(png_ptr->push_chunk_name[1]>90 && png_ptr->push_chunk_name[1]< 97) ||
png_ptr->push_chunk_name[2] <41 || png_ptr->push_chunk_name[2]> 122 ||
(png_ptr->push_chunk_name[2]>90 && png_ptr->push_chunk_name[2]< 97) ||
png_ptr->push_chunk_name[3] <41 || png_ptr->push_chunk_name[3]> 122 ||
(png_ptr->push_chunk_name[3]>90 && png_ptr->push_chunk_name[3]< 97))
{
char msg[45];
sprintf(msg, "Invalid chunk type 0x%02X 0x%02X 0x%02X 0x%02X",
png_ptr->push_chunk_name[0], png_ptr->push_chunk_name[1],
png_ptr->push_chunk_name[2], png_ptr->push_chunk_name[3]);
png_error(png_ptr, msg);
}
if ((png_ptr->push_chunk_name[0] & 0x20) == 0)
{
char msg[40];
sprintf(msg, "Unknown critical chunk %c%c%c%c",
png_ptr->push_chunk_name[0], png_ptr->push_chunk_name[1],
png_ptr->push_chunk_name[2], png_ptr->push_chunk_name[3]);
png_error(png_ptr, msg);
}
png_push_crc_skip(png_ptr, png_ptr->push_length);
}
if (png_ptr->mode == PNG_AT_LAST_IDAT)
png_ptr->mode = PNG_AFTER_IDAT;
png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER;
}
void
png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr,
png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn,
png_progressive_end_ptr end_fn)
{
png_ptr->info_fn = info_fn;
png_ptr->row_fn = row_fn;
png_ptr->end_fn = end_fn;
png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer);
}
void
png_progressive_combine_row (png_structp png_ptr,
png_bytep old_row, png_bytep new_row)
{
if (new_row)
png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
}
#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.