diff options
Diffstat (limited to 'libpng/pngpread.c')
| -rw-r--r-- | libpng/pngpread.c | 1502 |
1 files changed, 1502 insertions, 0 deletions
diff --git a/libpng/pngpread.c b/libpng/pngpread.c new file mode 100644 index 0000000..9207cbd --- /dev/null +++ b/libpng/pngpread.c @@ -0,0 +1,1502 @@ + +/* pngpread.c - read a png file in push mode + * + * libpng 1.2.1 - December 12, 2001 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1998-2001 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) +{ + 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) +{ + 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_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_sRGB_SUPPORTED) + PNG_sRGB; +#endif +#if defined(PNG_READ_sPLT_SUPPORTED) + PNG_sPLT; +#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_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_32(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_IHDR, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + 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_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_bytep)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_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; + } + 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); + } +#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)) + { + 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)) + { + 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)) + { + png_push_handle_iTXt(png_ptr, info_ptr, png_ptr->push_length); + } +#endif + else + { + 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 /* PRIVATE */ +png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) +{ + png_bytep ptr; + + 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; + + 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_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_32(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_bytep)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); + 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); + 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; + } +} + +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)) + { + 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_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_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf, + 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) +/* 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 */ + const int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; + + /* offset to next interlace block */ + const int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; + + /* start of interlace block in the y direction */ + const int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; + + /* offset to next interlace block in the y direction */ + const int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; + + /* Width of interlace block. This is not currently used - if you need + * it, uncomment it here and in png.h + const int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1}; + */ + + /* Height of interlace block. This is not currently used - if you need + * it, uncomment it here and in png.h + 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 + { + png_ptr->pass++; + if ((png_ptr->pass == 1 && png_ptr->width < 5) || + (png_ptr->pass == 3 && png_ptr->width < 3) || + (png_ptr->pass == 5 && png_ptr->width < 2)) + 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) + break; + + 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]; + + } 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"); + /* to quiet some compiler warnings */ + if(info_ptr == NULL) return; + } + +#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; + + 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; + png_ptr->current_text = 0; + + 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)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; + + png_set_text(png_ptr, info_ptr, text_ptr, 1); + + png_free(png_ptr, key); + png_free(png_ptr, text_ptr); + } +} +#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"); + /* to quiet some compiler warnings */ + if(info_ptr == NULL) return; + } + +#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; + png_ptr->current_text = 0; + + for (text = key; *text; text++) + /* empty loop */ ; + + /* zTXt can't have zero text */ + if (text == key + png_ptr->current_text_size) + { + png_free(png_ptr, key); + return; + } + + text++; + + if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */ + { + 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_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_free(png_ptr, key); + png_free(png_ptr, text); + return; + } + + png_free(png_ptr, key); + key = text; + text += key_size; + + text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)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; + + png_set_text(png_ptr, info_ptr, text_ptr, 1); + + png_free(png_ptr, key); + png_free(png_ptr, text_ptr); + } +} +#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"); + /* to quiet some compiler warnings */ + if(info_ptr == NULL) return; + } + +#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; + + 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; + png_ptr->current_text = 0; + + for (lang = key; *lang; lang++) + /* empty loop */ ; + + if (lang != key + png_ptr->current_text_size) + 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 */ + + for (text = lang_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)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); + + png_set_text(png_ptr, info_ptr, text_ptr, 1); + + png_free(png_ptr, text_ptr); + } +} +#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) != + 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"); + + /* to quiet compiler warnings about unused info_ptr */ + if (info_ptr == NULL) + return; + } + +#if defined(PNG_READ_UNKNOWN_CHUNKS_SUPPORTED) + if (png_ptr->flags & PNG_FLAG_KEEP_UNKNOWN_CHUNKS) + { + png_unknown_chunk chunk; + +#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_strcpy((png_charp)chunk.name, (png_charp)png_ptr->chunk_name); + chunk.data = (png_bytep)png_malloc(png_ptr, length); + png_crc_read(png_ptr, chunk.data, length); + chunk.size = length; +#if defined(PNG_READ_USER_CHUNKS_SUPPORTED) + if(png_ptr->read_user_chunk_fn != NULL) + { + /* callback to user unknown chunk handler */ + if ((*(png_ptr->read_user_chunk_fn)) (png_ptr, &chunk) <= 0) + { + if (!(png_ptr->chunk_name[0] & 0x20)) + if(png_handle_as_unknown(png_ptr, png_ptr->chunk_name) != + HANDLE_CHUNK_ALWAYS) + png_chunk_error(png_ptr, "unknown critical chunk"); + } + png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1); + } + else +#endif + png_set_unknown_chunks(png_ptr, info_ptr, &chunk, 1); + png_free(png_ptr, chunk.data); + } + 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 + const int FARDATA png_pass_dsp_mask[7] = + {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; +#endif + 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) +{ + 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) +{ + return png_ptr->io_ptr; +} +#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ |