--- /dev/null
+
+/* pngpread.c - read a png file in push mode
+ *
+ * Last changed in libpng 1.2.27 [April 29, 2008]
+ * For conditions of distribution and use, see copyright notice in png.h
+ * Copyright (c) 1998-2008 Glenn Randers-Pehrson
+ * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
+ * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
+ */
+
+#define PNG_INTERNAL
+#include "png.h"
+
+#ifdef PNG_PROGRESSIVE_READ_SUPPORTED
+
+/* push model modes */
+#define PNG_READ_SIG_MODE 0
+#define PNG_READ_CHUNK_MODE 1
+#define PNG_READ_IDAT_MODE 2
+#define PNG_SKIP_MODE 3
+#define PNG_READ_tEXt_MODE 4
+#define PNG_READ_zTXt_MODE 5
+#define PNG_READ_DONE_MODE 6
+#define PNG_READ_iTXt_MODE 7
+#define PNG_ERROR_MODE 8
+
+void PNGAPI
+png_process_data(png_structp png_ptr, png_infop info_ptr,
+ png_bytep buffer, png_size_t buffer_size)
+{
+ if(png_ptr == NULL || info_ptr == NULL) return;
+ png_push_restore_buffer(png_ptr, buffer, buffer_size);
+
+ while (png_ptr->buffer_size)
+ {
+ png_process_some_data(png_ptr, info_ptr);
+ }
+}
+
+/* What we do with the incoming data depends on what we were previously
+ * doing before we ran out of data...
+ */
+void /* PRIVATE */
+png_process_some_data(png_structp png_ptr, png_infop info_ptr)
+{
+ if(png_ptr == NULL) return;
+ switch (png_ptr->process_mode)
+ {
+ case PNG_READ_SIG_MODE:
+ {
+ png_push_read_sig(png_ptr, info_ptr);
+ break;
+ }
+ case PNG_READ_CHUNK_MODE:
+ {
+ png_push_read_chunk(png_ptr, info_ptr);
+ break;
+ }
+ case PNG_READ_IDAT_MODE:
+ {
+ png_push_read_IDAT(png_ptr);
+ break;
+ }
+#if defined(PNG_READ_tEXt_SUPPORTED)
+ case PNG_READ_tEXt_MODE:
+ {
+ png_push_read_tEXt(png_ptr, info_ptr);
+ break;
+ }
+#endif
+#if defined(PNG_READ_zTXt_SUPPORTED)
+ case PNG_READ_zTXt_MODE:
+ {
+ png_push_read_zTXt(png_ptr, info_ptr);
+ break;
+ }
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+ case PNG_READ_iTXt_MODE:
+ {
+ png_push_read_iTXt(png_ptr, info_ptr);
+ break;
+ }
+#endif
+ case PNG_SKIP_MODE:
+ {
+ png_push_crc_finish(png_ptr);
+ break;
+ }
+ default:
+ {
+ png_ptr->buffer_size = 0;
+ break;
+ }
+ }
+}
+
+/* Read any remaining signature bytes from the stream and compare them with
+ * the correct PNG signature. It is possible that this routine is called
+ * with bytes already read from the signature, either because they have been
+ * checked by the calling application, or because of multiple calls to this
+ * routine.
+ */
+void /* PRIVATE */
+png_push_read_sig(png_structp png_ptr, png_infop info_ptr)
+{
+ png_size_t num_checked = png_ptr->sig_bytes,
+ num_to_check = 8 - num_checked;
+
+ if (png_ptr->buffer_size < num_to_check)
+ {
+ num_to_check = png_ptr->buffer_size;
+ }
+
+ png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]),
+ num_to_check);
+ png_ptr->sig_bytes = (png_byte)(png_ptr->sig_bytes+num_to_check);
+
+ 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");
+ }
+ else
+ {
+ if (png_ptr->sig_bytes >= 8)
+ {
+ png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+ }
+ }
+}
+
+void /* PRIVATE */
+png_push_read_chunk(png_structp png_ptr, png_infop info_ptr)
+{
+#ifdef PNG_USE_LOCAL_ARRAYS
+ PNG_CONST PNG_IHDR;
+ PNG_CONST PNG_IDAT;
+ PNG_CONST PNG_IEND;
+ PNG_CONST PNG_PLTE;
+#if defined(PNG_READ_bKGD_SUPPORTED)
+ PNG_CONST PNG_bKGD;
+#endif
+#if defined(PNG_READ_cHRM_SUPPORTED)
+ PNG_CONST PNG_cHRM;
+#endif
+#if defined(PNG_READ_gAMA_SUPPORTED)
+ PNG_CONST PNG_gAMA;
+#endif
+#if defined(PNG_READ_hIST_SUPPORTED)
+ PNG_CONST PNG_hIST;
+#endif
+#if defined(PNG_READ_iCCP_SUPPORTED)
+ PNG_CONST PNG_iCCP;
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+ PNG_CONST PNG_iTXt;
+#endif
+#if defined(PNG_READ_oFFs_SUPPORTED)
+ PNG_CONST PNG_oFFs;
+#endif
+#if defined(PNG_READ_pCAL_SUPPORTED)
+ PNG_CONST PNG_pCAL;
+#endif
+#if defined(PNG_READ_pHYs_SUPPORTED)
+ PNG_CONST PNG_pHYs;
+#endif
+#if defined(PNG_READ_sBIT_SUPPORTED)
+ PNG_CONST PNG_sBIT;
+#endif
+#if defined(PNG_READ_sCAL_SUPPORTED)
+ PNG_CONST PNG_sCAL;
+#endif
+#if defined(PNG_READ_sRGB_SUPPORTED)
+ PNG_CONST PNG_sRGB;
+#endif
+#if defined(PNG_READ_sPLT_SUPPORTED)
+ PNG_CONST PNG_sPLT;
+#endif
+#if defined(PNG_READ_tEXt_SUPPORTED)
+ PNG_CONST PNG_tEXt;
+#endif
+#if defined(PNG_READ_tIME_SUPPORTED)
+ PNG_CONST PNG_tIME;
+#endif
+#if defined(PNG_READ_tRNS_SUPPORTED)
+ PNG_CONST PNG_tRNS;
+#endif
+#if defined(PNG_READ_zTXt_SUPPORTED)
+ PNG_CONST PNG_zTXt;
+#endif
+#endif /* PNG_USE_LOCAL_ARRAYS */
+ /* First we make sure we have enough data for the 4 byte chunk name
+ * and the 4 byte chunk length before proceeding with decoding the
+ * chunk data. To fully decode each of these chunks, we also make
+ * sure we have enough data in the buffer for the 4 byte CRC at the
+ * end of every chunk (except IDAT, which is handled separately).
+ */
+ if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
+ {
+ png_byte chunk_length[4];
+
+ if (png_ptr->buffer_size < 8)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_push_fill_buffer(png_ptr, chunk_length, 4);
+ png_ptr->push_length = png_get_uint_31(png_ptr,chunk_length);
+ png_reset_crc(png_ptr);
+ png_crc_read(png_ptr, png_ptr->chunk_name, 4);
+ png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+ }
+
+ if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ if(png_ptr->mode & PNG_AFTER_IDAT)
+ png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT;
+
+ if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ if (png_ptr->push_length != 13)
+ png_error(png_ptr, "Invalid IHDR length");
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length);
+ }
+ else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length);
+
+ png_ptr->process_mode = PNG_READ_DONE_MODE;
+ png_push_have_end(png_ptr, info_ptr);
+ }
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ else if (png_handle_as_unknown(png_ptr, png_ptr->chunk_name))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ png_ptr->mode |= PNG_HAVE_IDAT;
+ png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
+ if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+ png_ptr->mode |= PNG_HAVE_PLTE;
+ else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ {
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before IDAT");
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ !(png_ptr->mode & PNG_HAVE_PLTE))
+ png_error(png_ptr, "Missing PLTE before IDAT");
+ }
+ }
+#endif
+ else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length);
+ }
+ else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ {
+ /* If we reach an IDAT chunk, this means we have read all of the
+ * header chunks, and we can start reading the image (or if this
+ * is called after the image has been read - we have an error).
+ */
+ if (!(png_ptr->mode & PNG_HAVE_IHDR))
+ png_error(png_ptr, "Missing IHDR before IDAT");
+ else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE &&
+ !(png_ptr->mode & PNG_HAVE_PLTE))
+ png_error(png_ptr, "Missing PLTE before IDAT");
+
+ if (png_ptr->mode & PNG_HAVE_IDAT)
+ {
+ if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT))
+ if (png_ptr->push_length == 0)
+ return;
+
+ if (png_ptr->mode & PNG_AFTER_IDAT)
+ png_error(png_ptr, "Too many IDAT's found");
+ }
+
+ 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_ptr);
+ png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
+ png_ptr->zstream.next_out = png_ptr->row_buf;
+ return;
+ }
+#if defined(PNG_READ_gAMA_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_sBIT_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_cHRM_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_sRGB_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_iCCP_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_iCCP, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_iCCP(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_sPLT_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_sPLT, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_sPLT(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_tRNS_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_bKGD_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_hIST_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_pHYs_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_oFFs_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_pCAL_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_sCAL_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_sCAL, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_sCAL(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_tIME_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_tEXt_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_zTXt_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+#if defined(PNG_READ_iTXt_SUPPORTED)
+ else if (!png_memcmp(png_ptr->chunk_name, png_iTXt, 4))
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length);
+ }
+#endif
+ else
+ {
+ if (png_ptr->push_length + 4 > png_ptr->buffer_size)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+ png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length);
+ }
+
+ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+}
+
+void /* PRIVATE */
+png_push_crc_skip(png_structp png_ptr, png_uint_32 skip)
+{
+ png_ptr->process_mode = PNG_SKIP_MODE;
+ png_ptr->skip_length = skip;
+}
+
+void /* PRIVATE */
+png_push_crc_finish(png_structp png_ptr)
+{
+ if (png_ptr->skip_length && png_ptr->save_buffer_size)
+ {
+ png_size_t save_size;
+
+ if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size)
+ save_size = (png_size_t)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 += save_size;
+ }
+ if (png_ptr->skip_length && png_ptr->current_buffer_size)
+ {
+ png_size_t save_size;
+
+ if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size)
+ save_size = (png_size_t)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 += save_size;
+ }
+ if (!png_ptr->skip_length)
+ {
+ if (png_ptr->buffer_size < 4)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_crc_finish(png_ptr, 0);
+ png_ptr->process_mode = PNG_READ_CHUNK_MODE;
+ }
+}
+
+void PNGAPI
+png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length)
+{
+ png_bytep ptr;
+
+ if(png_ptr == NULL) return;
+ ptr = buffer;
+ if (png_ptr->save_buffer_size)
+ {
+ png_size_t 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, save_size);
+ length -= save_size;
+ ptr += save_size;
+ png_ptr->buffer_size -= save_size;
+ png_ptr->save_buffer_size -= save_size;
+ png_ptr->save_buffer_ptr += save_size;
+ }
+ if (length && png_ptr->current_buffer_size)
+ {
+ png_size_t 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, save_size);
+ png_ptr->buffer_size -= save_size;
+ png_ptr->current_buffer_size -= save_size;
+ png_ptr->current_buffer_ptr += save_size;
+ }
+}
+
+void /* PRIVATE */
+png_push_save_buffer(png_structp png_ptr)
+{
+ if (png_ptr->save_buffer_size)
+ {
+ if (png_ptr->save_buffer_ptr != png_ptr->save_buffer)
+ {
+ png_size_t i,istop;
+ png_bytep sp;
+ png_bytep dp;
+
+ istop = png_ptr->save_buffer_size;
+ for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer;
+ i < istop; i++, sp++, dp++)
+ {
+ *dp = *sp;
+ }
+ }
+ }
+ if (png_ptr->save_buffer_size + png_ptr->current_buffer_size >
+ png_ptr->save_buffer_max)
+ {
+ png_size_t new_max;
+ png_bytep old_buffer;
+
+ if (png_ptr->save_buffer_size > PNG_SIZE_MAX -
+ (png_ptr->current_buffer_size + 256))
+ {
+ png_error(png_ptr, "Potential overflow of save_buffer");
+ }
+ new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
+ old_buffer = png_ptr->save_buffer;
+ png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr,
+ (png_uint_32)new_max);
+ png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
+ png_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_ptr->save_buffer_size,
+ png_ptr->current_buffer_ptr, 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 /* PRIVATE */
+png_push_restore_buffer(png_structp png_ptr, png_bytep buffer,
+ png_size_t 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 /* PRIVATE */
+png_push_read_IDAT(png_structp png_ptr)
+{
+#ifdef PNG_USE_LOCAL_ARRAYS
+ PNG_CONST PNG_IDAT;
+#endif
+ if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER))
+ {
+ png_byte chunk_length[4];
+
+ if (png_ptr->buffer_size < 8)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_push_fill_buffer(png_ptr, chunk_length, 4);
+ png_ptr->push_length = png_get_uint_31(png_ptr,chunk_length);
+ png_reset_crc(png_ptr);
+ png_crc_read(png_ptr, png_ptr->chunk_name, 4);
+ png_ptr->mode |= PNG_HAVE_CHUNK_HEADER;
+
+ if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4))
+ {
+ png_ptr->process_mode = PNG_READ_CHUNK_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_size_t save_size;
+
+ if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size)
+ {
+ save_size = (png_size_t)png_ptr->idat_size;
+ /* check for overflow */
+ if((png_uint_32)save_size != png_ptr->idat_size)
+ png_error(png_ptr, "save_size overflowed in pngpread");
+ }
+ else
+ save_size = png_ptr->save_buffer_size;
+
+ png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size);
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
+ 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 += save_size;
+ }
+ if (png_ptr->idat_size && png_ptr->current_buffer_size)
+ {
+ png_size_t save_size;
+
+ if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size)
+ {
+ save_size = (png_size_t)png_ptr->idat_size;
+ /* check for overflow */
+ if((png_uint_32)save_size != png_ptr->idat_size)
+ png_error(png_ptr, "save_size overflowed in pngpread");
+ }
+ else
+ save_size = png_ptr->current_buffer_size;
+
+ png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size);
+ if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED))
+ 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 += save_size;
+ }
+ if (!png_ptr->idat_size)
+ {
+ if (png_ptr->buffer_size < 4)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_crc_finish(png_ptr, 0);
+ png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER;
+ png_ptr->mode |= PNG_AFTER_IDAT;
+ }
+}
+
+void /* PRIVATE */
+png_process_IDAT_data(png_structp png_ptr, png_bytep buffer,
+ png_size_t 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;
+ for(;;)
+ {
+ ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH);
+ if (ret != Z_OK)
+ {
+ 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_AFTER_IDAT;
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+ break;
+ }
+ else if (ret == Z_BUF_ERROR)
+ break;
+ else
+ png_error(png_ptr, "Decompression Error");
+ }
+ if (!(png_ptr->zstream.avail_out))
+ {
+ if ((
+#if defined(PNG_READ_INTERLACING_SUPPORTED)
+ png_ptr->interlaced && png_ptr->pass > 6) ||
+ (!png_ptr->interlaced &&
+#endif
+ png_ptr->row_number == png_ptr->num_rows))
+ {
+ if (png_ptr->zstream.avail_in)
+ png_warning(png_ptr, "Too much data in IDAT chunks");
+ png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED;
+ break;
+ }
+ png_push_process_row(png_ptr);
+ png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes;
+ png_ptr->zstream.next_out = png_ptr->row_buf;
+ }
+ else
+ break;
+ }
+}
+
+void /* PRIVATE */
+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_ROWBYTES(png_ptr->row_info.pixel_depth,
+ png_ptr->row_info.width);
+
+ 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_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf,
+ png_ptr->rowbytes + 1);
+
+ if (png_ptr->transformations || (png_ptr->flags&PNG_FLAG_STRIP_ALPHA))
+ 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)
+/* old interface (pre-1.0.9):
+ png_do_read_interlace(&(png_ptr->row_info),
+ png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations);
+ */
+ png_do_read_interlace(png_ptr);
+
+ 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); /* updates png_ptr->pass */
+ }
+ if (png_ptr->pass == 2) /* pass 1 might be empty */
+ {
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, png_bytep_NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+ if (png_ptr->pass == 4 && png_ptr->height <= 4)
+ {
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, png_bytep_NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ }
+ if (png_ptr->pass == 6 && png_ptr->height <= 4)
+ {
+ png_push_have_row(png_ptr, png_bytep_NULL);
+ 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) /* skip top 4 generated rows */
+ {
+ for (i = 0; i < 4 && png_ptr->pass == 2; i++)
+ {
+ png_push_have_row(png_ptr, png_bytep_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, png_bytep_NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ if (png_ptr->pass == 4) /* pass 3 might be empty */
+ {
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, png_bytep_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) /* skip top two generated rows */
+ {
+ for (i = 0; i < 2 && png_ptr->pass == 4; i++)
+ {
+ png_push_have_row(png_ptr, png_bytep_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, png_bytep_NULL);
+ png_read_push_finish_row(png_ptr);
+ }
+ if (png_ptr->pass == 6) /* pass 5 might be empty */
+ {
+ png_push_have_row(png_ptr, png_bytep_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) /* skip top generated row */
+ {
+ png_push_have_row(png_ptr, png_bytep_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, png_bytep_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 /* PRIVATE */
+png_read_push_finish_row(png_structp png_ptr)
+{
+#ifdef PNG_USE_LOCAL_ARRAYS
+ /* arrays to facilitate easy interlacing - use pass (0 - 6) as index */
+
+ /* start of interlace block */
+ PNG_CONST int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0};
+
+ /* offset to next interlace block */
+ PNG_CONST int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1};
+
+ /* start of interlace block in the y direction */
+ PNG_CONST int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1};
+
+ /* offset to next interlace block in the y direction */
+ PNG_CONST int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2};
+
+ /* Height of interlace block. This is not currently used - if you need
+ * it, uncomment it here and in png.h
+ PNG_CONST int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1};
+ */
+#endif
+
+ 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_check(png_ptr, png_ptr->prev_row, 0,
+ png_ptr->rowbytes + 1);
+ do
+ {
+ int pass;
+ pass = png_ptr->pass;
+ pass++;
+ if ((pass == 1 && png_ptr->width < 5) ||
+ (pass == 3 && png_ptr->width < 3) ||
+ (pass == 5 && png_ptr->width < 2))
+ pass++;
+
+ if (pass > 7)
+ pass--;
+ png_ptr->pass = (png_byte) pass;
+ if (pass < 7)
+ {
+ png_ptr->iwidth = (png_ptr->width +
+ png_pass_inc[pass] - 1 -
+ png_pass_start[pass]) /
+ png_pass_inc[pass];
+
+ png_ptr->irowbytes = PNG_ROWBYTES(png_ptr->pixel_depth,
+ png_ptr->iwidth) + 1;
+
+ if (png_ptr->transformations & PNG_INTERLACE)
+ break;
+
+ png_ptr->num_rows = (png_ptr->height +
+ png_pass_yinc[pass] - 1 -
+ png_pass_ystart[pass]) /
+ png_pass_yinc[pass];
+ }
+ else
+ break;
+
+ } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
+ }
+}
+
+#if defined(PNG_READ_tEXt_SUPPORTED)
+void /* PRIVATE */
+png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
+ length)
+{
+ if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
+ {
+ png_error(png_ptr, "Out of place tEXt");
+ info_ptr = info_ptr; /* to quiet some compiler warnings */
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ png_ptr->skip_length = 0; /* This may not be necessary */
+
+ if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
+ {
+ png_warning(png_ptr, "tEXt chunk too large to fit in memory");
+ png_ptr->skip_length = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ png_ptr->current_text = (png_charp)png_malloc(png_ptr,
+ (png_uint_32)(length+1));
+ png_ptr->current_text[length] = '\0';
+ png_ptr->current_text_ptr = png_ptr->current_text;
+ png_ptr->current_text_size = (png_size_t)length;
+ png_ptr->current_text_left = (png_size_t)length;
+ png_ptr->process_mode = PNG_READ_tEXt_MODE;
+}
+
+void /* PRIVATE */
+png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr->buffer_size && png_ptr->current_text_left)
+ {
+ png_size_t 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_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
+ png_ptr->current_text_left -= text_size;
+ png_ptr->current_text_ptr += text_size;
+ }
+ if (!(png_ptr->current_text_left))
+ {
+ png_textp text_ptr;
+ png_charp text;
+ png_charp key;
+ int ret;
+
+ if (png_ptr->buffer_size < 4)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_push_crc_finish(png_ptr);
+
+#if defined(PNG_MAX_MALLOC_64K)
+ if (png_ptr->skip_length)
+ return;
+#endif
+
+ key = png_ptr->current_text;
+
+ for (text = key; *text; text++)
+ /* empty loop */ ;
+
+ if (text < key + png_ptr->current_text_size)
+ text++;
+
+ text_ptr = (png_textp)png_malloc(png_ptr,
+ (png_uint_32)png_sizeof(png_text));
+ text_ptr->compression = PNG_TEXT_COMPRESSION_NONE;
+ text_ptr->key = key;
+#ifdef PNG_iTXt_SUPPORTED
+ text_ptr->lang = NULL;
+ text_ptr->lang_key = NULL;
+#endif
+ text_ptr->text = text;
+
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_free(png_ptr, key);
+ png_free(png_ptr, text_ptr);
+ png_ptr->current_text = NULL;
+
+ if (ret)
+ png_warning(png_ptr, "Insufficient memory to store text chunk.");
+ }
+}
+#endif
+
+#if defined(PNG_READ_zTXt_SUPPORTED)
+void /* PRIVATE */
+png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
+ length)
+{
+ if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
+ {
+ png_error(png_ptr, "Out of place zTXt");
+ info_ptr = info_ptr; /* to quiet some compiler warnings */
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ /* We can't handle zTXt chunks > 64K, since we don't have enough space
+ * to be able to store the uncompressed data. Actually, the threshold
+ * is probably around 32K, but it isn't as definite as 64K is.
+ */
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "zTXt chunk too large to fit in memory");
+ png_push_crc_skip(png_ptr, length);
+ return;
+ }
+#endif
+
+ png_ptr->current_text = (png_charp)png_malloc(png_ptr,
+ (png_uint_32)(length+1));
+ png_ptr->current_text[length] = '\0';
+ png_ptr->current_text_ptr = png_ptr->current_text;
+ png_ptr->current_text_size = (png_size_t)length;
+ png_ptr->current_text_left = (png_size_t)length;
+ png_ptr->process_mode = PNG_READ_zTXt_MODE;
+}
+
+void /* PRIVATE */
+png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr->buffer_size && png_ptr->current_text_left)
+ {
+ png_size_t text_size;
+
+ if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left)
+ text_size = png_ptr->buffer_size;
+ else
+ text_size = png_ptr->current_text_left;
+ png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
+ png_ptr->current_text_left -= text_size;
+ png_ptr->current_text_ptr += text_size;
+ }
+ if (!(png_ptr->current_text_left))
+ {
+ png_textp text_ptr;
+ png_charp text;
+ png_charp key;
+ int ret;
+ png_size_t text_size, key_size;
+
+ if (png_ptr->buffer_size < 4)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_push_crc_finish(png_ptr);
+
+ key = png_ptr->current_text;
+
+ for (text = key; *text; text++)
+ /* empty loop */ ;
+
+ /* zTXt can't have zero text */
+ if (text >= key + png_ptr->current_text_size)
+ {
+ png_ptr->current_text = NULL;
+ png_free(png_ptr, key);
+ return;
+ }
+
+ text++;
+
+ if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */
+ {
+ png_ptr->current_text = NULL;
+ png_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 = (uInt)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_ptr->current_text = NULL;
+ png_free(png_ptr, key);
+ png_free(png_ptr, text);
+ return;
+ }
+ if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END)
+ {
+ if (text == NULL)
+ {
+ text = (png_charp)png_malloc(png_ptr,
+ (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
+ + key_size + 1));
+ png_memcpy(text + key_size, png_ptr->zbuf,
+ png_ptr->zbuf_size - png_ptr->zstream.avail_out);
+ png_memcpy(text, key, key_size);
+ text_size = key_size + png_ptr->zbuf_size -
+ png_ptr->zstream.avail_out;
+ *(text + text_size) = '\0';
+ }
+ else
+ {
+ png_charp tmp;
+
+ tmp = text;
+ text = (png_charp)png_malloc(png_ptr, text_size +
+ (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out
+ + 1));
+ png_memcpy(text, tmp, text_size);
+ png_free(png_ptr, tmp);
+ png_memcpy(text + text_size, png_ptr->zbuf,
+ png_ptr->zbuf_size - png_ptr->zstream.avail_out);
+ text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out;
+ *(text + 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_ptr->current_text = NULL;
+ png_free(png_ptr, key);
+ png_free(png_ptr, text);
+ return;
+ }
+
+ png_ptr->current_text = NULL;
+ png_free(png_ptr, key);
+ key = text;
+ text += key_size;
+
+ text_ptr = (png_textp)png_malloc(png_ptr,
+ (png_uint_32)png_sizeof(png_text));
+ text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt;
+ text_ptr->key = key;
+#ifdef PNG_iTXt_SUPPORTED
+ text_ptr->lang = NULL;
+ text_ptr->lang_key = NULL;
+#endif
+ text_ptr->text = text;
+
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_free(png_ptr, key);
+ png_free(png_ptr, text_ptr);
+
+ if (ret)
+ png_warning(png_ptr, "Insufficient memory to store text chunk.");
+ }
+}
+#endif
+
+#if defined(PNG_READ_iTXt_SUPPORTED)
+void /* PRIVATE */
+png_push_handle_iTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32
+ length)
+{
+ if (!(png_ptr->mode & PNG_HAVE_IHDR) || (png_ptr->mode & PNG_HAVE_IEND))
+ {
+ png_error(png_ptr, "Out of place iTXt");
+ info_ptr = info_ptr; /* to quiet some compiler warnings */
+ }
+
+#ifdef PNG_MAX_MALLOC_64K
+ png_ptr->skip_length = 0; /* This may not be necessary */
+
+ if (length > (png_uint_32)65535L) /* Can't hold entire string in memory */
+ {
+ png_warning(png_ptr, "iTXt chunk too large to fit in memory");
+ png_ptr->skip_length = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+
+ png_ptr->current_text = (png_charp)png_malloc(png_ptr,
+ (png_uint_32)(length+1));
+ png_ptr->current_text[length] = '\0';
+ png_ptr->current_text_ptr = png_ptr->current_text;
+ png_ptr->current_text_size = (png_size_t)length;
+ png_ptr->current_text_left = (png_size_t)length;
+ png_ptr->process_mode = PNG_READ_iTXt_MODE;
+}
+
+void /* PRIVATE */
+png_push_read_iTXt(png_structp png_ptr, png_infop info_ptr)
+{
+
+ if (png_ptr->buffer_size && png_ptr->current_text_left)
+ {
+ png_size_t 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_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size);
+ png_ptr->current_text_left -= text_size;
+ png_ptr->current_text_ptr += text_size;
+ }
+ if (!(png_ptr->current_text_left))
+ {
+ png_textp text_ptr;
+ png_charp key;
+ int comp_flag;
+ png_charp lang;
+ png_charp lang_key;
+ png_charp text;
+ int ret;
+
+ if (png_ptr->buffer_size < 4)
+ {
+ png_push_save_buffer(png_ptr);
+ return;
+ }
+
+ png_push_crc_finish(png_ptr);
+
+#if defined(PNG_MAX_MALLOC_64K)
+ if (png_ptr->skip_length)
+ return;
+#endif
+
+ key = png_ptr->current_text;
+
+ for (lang = key; *lang; lang++)
+ /* empty loop */ ;
+
+ if (lang < key + png_ptr->current_text_size - 3)
+ lang++;
+
+ comp_flag = *lang++;
+ lang++; /* skip comp_type, always zero */
+
+ for (lang_key = lang; *lang_key; lang_key++)
+ /* empty loop */ ;
+ lang_key++; /* skip NUL separator */
+
+ text=lang_key;
+ if (lang_key < key + png_ptr->current_text_size - 1)
+ {
+ for (; *text; text++)
+ /* empty loop */ ;
+ }
+
+ if (text < key + png_ptr->current_text_size)
+ text++;
+
+ text_ptr = (png_textp)png_malloc(png_ptr,
+ (png_uint_32)png_sizeof(png_text));
+ text_ptr->compression = comp_flag + 2;
+ text_ptr->key = key;
+ text_ptr->lang = lang;
+ text_ptr->lang_key = lang_key;
+ text_ptr->text = text;
+ text_ptr->text_length = 0;
+ text_ptr->itxt_length = png_strlen(text);
+
+ ret = png_set_text_2(png_ptr, info_ptr, text_ptr, 1);
+
+ png_ptr->current_text = NULL;
+
+ png_free(png_ptr, text_ptr);
+ if (ret)
+ png_warning(png_ptr, "Insufficient memory to store iTXt chunk.");
+ }
+}
+#endif
+
+/* This function is called when we haven't found a handler for this
+ * chunk. If there isn't a problem with the chunk itself (ie a bad chunk
+ * name or a critical chunk), the chunk is (currently) silently ignored.
+ */
+void /* PRIVATE */
+png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32
+ length)
+{
+ png_uint_32 skip=0;
+ png_check_chunk_name(png_ptr, png_ptr->chunk_name);
+
+ if (!(png_ptr->chunk_name[0] & 0x20))
+ {
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+ if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+ PNG_HANDLE_CHUNK_ALWAYS
+#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
+ && png_ptr->read_user_chunk_fn == NULL
+#endif
+ )
+#endif
+ png_chunk_error(png_ptr, "unknown critical chunk");
+
+ info_ptr = info_ptr; /* to quiet some compiler warnings */
+ }
+
+#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED)
+ if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS)
+ {
+#ifdef PNG_MAX_MALLOC_64K
+ if (length > (png_uint_32)65535L)
+ {
+ png_warning(png_ptr, "unknown chunk too large to fit in memory");
+ skip = length - (png_uint_32)65535L;
+ length = (png_uint_32)65535L;
+ }
+#endif
+ png_memcpy((png_charp)png_ptr->unknown_chunk.name,
+ (png_charp)png_ptr->chunk_name,
+ png_sizeof(png_ptr->unknown_chunk.name));
+ png_ptr->unknown_chunk.name[png_sizeof(png_ptr->unknown_chunk.name)-1]='\0';
+
+ png_ptr->unknown_chunk.size = (png_size_t)length;
+ if (length == 0)
+ png_ptr->unknown_chunk.data = NULL;
+ else
+ {
+ png_ptr->unknown_chunk.data = (png_bytep)png_malloc(png_ptr, length);
+ png_crc_read(png_ptr, (png_bytep)png_ptr->unknown_chunk.data, length);
+ }
+#if defined(PNG_READ_USER_CHUNKS_SUPPORTED)
+ if(png_ptr->read_user_chunk_fn != NULL)
+ {
+ /* callback to user unknown chunk handler */
+ int ret;
+ ret = (*(png_ptr->read_user_chunk_fn))
+ (png_ptr, &png_ptr->unknown_chunk);
+ if (ret < 0)
+ png_chunk_error(png_ptr, "error in user chunk");
+ if (ret == 0)
+ {
+ if (!(png_ptr->chunk_name[0] & 0x20))
+ if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) !=
+ PNG_HANDLE_CHUNK_ALWAYS)
+ png_chunk_error(png_ptr, "unknown critical chunk");
+ png_set_unknown_chunks(png_ptr, info_ptr,
+ &png_ptr->unknown_chunk, 1);
+ }
+ }
+ else
+#endif
+ png_set_unknown_chunks(png_ptr, info_ptr, &png_ptr->unknown_chunk, 1);
+ png_free(png_ptr, png_ptr->unknown_chunk.data);
+ png_ptr->unknown_chunk.data = NULL;
+ }
+ else
+#endif
+ skip=length;
+ png_push_crc_skip(png_ptr, skip);
+}
+
+void /* PRIVATE */
+png_push_have_info(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr->info_fn != NULL)
+ (*(png_ptr->info_fn))(png_ptr, info_ptr);
+}
+
+void /* PRIVATE */
+png_push_have_end(png_structp png_ptr, png_infop info_ptr)
+{
+ if (png_ptr->end_fn != NULL)
+ (*(png_ptr->end_fn))(png_ptr, info_ptr);
+}
+
+void /* PRIVATE */
+png_push_have_row(png_structp png_ptr, png_bytep row)
+{
+ if (png_ptr->row_fn != NULL)
+ (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number,
+ (int)png_ptr->pass);
+}
+
+void PNGAPI
+png_progressive_combine_row (png_structp png_ptr,
+ png_bytep old_row, png_bytep new_row)
+{
+#ifdef PNG_USE_LOCAL_ARRAYS
+ PNG_CONST int FARDATA png_pass_dsp_mask[7] =
+ {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff};
+#endif
+ if(png_ptr == NULL) return;
+ if (new_row != NULL) /* new_row must == png_ptr->row_buf here. */
+ png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]);
+}
+
+void PNGAPI
+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)
+{
+ if(png_ptr == NULL) return;
+ 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);
+}
+
+png_voidp PNGAPI
+png_get_progressive_ptr(png_structp png_ptr)
+{
+ if(png_ptr == NULL) return (NULL);
+ return png_ptr->io_ptr;
+}
+#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
projects / opencv / blobdiff