diff options
Diffstat (limited to 'png/pngpread.c')
| -rw-r--r-- | png/pngpread.c | 1286 |
1 files changed, 0 insertions, 1286 deletions
diff --git a/png/pngpread.c b/png/pngpread.c deleted file mode 100644 index 819db03..0000000 --- a/png/pngpread.c +++ /dev/null @@ -1,1286 +0,0 @@ - -/* pngpread.c - read a png file in push mode - * - * Last changed in libpng 1.6.11 [June 12, 2014] - * Copyright (c) 1998-2014 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.) - * - * This code is released under the libpng license. - * For conditions of distribution and use, see the disclaimer - * and license in png.h - */ - -#include "pngpriv.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_structrp png_ptr, png_inforp 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); - } -} - -png_size_t PNGAPI -png_process_data_pause(png_structrp png_ptr, int save) -{ - if (png_ptr != NULL) - { - /* It's easiest for the caller if we do the save, then the caller doesn't - * have to supply the same data again: - */ - if (save != 0) - png_push_save_buffer(png_ptr); - else - { - /* This includes any pending saved bytes: */ - png_size_t remaining = png_ptr->buffer_size; - png_ptr->buffer_size = 0; - - /* So subtract the saved buffer size, unless all the data - * is actually 'saved', in which case we just return 0 - */ - if (png_ptr->save_buffer_size < remaining) - return remaining - png_ptr->save_buffer_size; - } - } - - return 0; -} - -png_uint_32 PNGAPI -png_process_data_skip(png_structrp png_ptr) -{ - png_uint_32 remaining = 0; - - if (png_ptr != NULL && png_ptr->process_mode == PNG_SKIP_MODE && - png_ptr->skip_length > 0) - { - /* At the end of png_process_data the buffer size must be 0 (see the loop - * above) so we can detect a broken call here: - */ - if (png_ptr->buffer_size != 0) - png_error(png_ptr, - "png_process_data_skip called inside png_process_data"); - - /* If is impossible for there to be a saved buffer at this point - - * otherwise we could not be in SKIP mode. This will also happen if - * png_process_skip is called inside png_process_data (but only very - * rarely.) - */ - if (png_ptr->save_buffer_size != 0) - png_error(png_ptr, "png_process_data_skip called with saved data"); - - remaining = png_ptr->skip_length; - png_ptr->skip_length = 0; - png_ptr->process_mode = PNG_READ_CHUNK_MODE; - } - - return remaining; -} - -/* 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_structrp png_ptr, png_inforp 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; - } - - 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_structrp png_ptr, png_inforp info_ptr) -{ - png_size_t num_checked = png_ptr->sig_bytes, /* SAFE, does not exceed 8 */ - 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_structrp png_ptr, png_inforp info_ptr) -{ - png_uint_32 chunk_name; -#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED - int keep; /* unknown handling method */ -#endif - - /* 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]; - png_byte chunk_tag[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, chunk_tag, 4); - png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); - png_check_chunk_name(png_ptr, png_ptr->chunk_name); - png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; - } - - chunk_name = png_ptr->chunk_name; - - if (chunk_name == png_IDAT) - { - if (png_ptr->mode & PNG_AFTER_IDAT) - png_ptr->mode |= PNG_HAVE_CHUNK_AFTER_IDAT; - - /* 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"); - - png_ptr->mode |= PNG_HAVE_IDAT; - png_ptr->process_mode = PNG_READ_IDAT_MODE; - - if (!(png_ptr->mode & PNG_HAVE_CHUNK_AFTER_IDAT)) - if (png_ptr->push_length == 0) - return; - - if (png_ptr->mode & PNG_AFTER_IDAT) - png_benign_error(png_ptr, "Too many IDATs found"); - } - - if (chunk_name == png_IHDR) - { - if (png_ptr->push_length != 13) - png_error(png_ptr, "Invalid IHDR length"); - - 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 (chunk_name == png_IEND) - { - 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 ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0) - { - if (png_ptr->push_length + 4 > png_ptr->buffer_size) - { - png_push_save_buffer(png_ptr); - return; - } - - png_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, keep); - - if (chunk_name == png_PLTE) - png_ptr->mode |= PNG_HAVE_PLTE; - } -#endif - - else if (chunk_name == png_PLTE) - { - 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 (chunk_name == png_IDAT) - { - png_ptr->idat_size = png_ptr->push_length; - png_ptr->process_mode = PNG_READ_IDAT_MODE; - png_push_have_info(png_ptr, info_ptr); - png_ptr->zstream.avail_out = - (uInt) PNG_ROWBYTES(png_ptr->pixel_depth, - png_ptr->iwidth) + 1; - png_ptr->zstream.next_out = png_ptr->row_buf; - return; - } - -#ifdef PNG_READ_gAMA_SUPPORTED - else if (png_ptr->chunk_name == png_gAMA) - { - 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 -#ifdef PNG_READ_sBIT_SUPPORTED - else if (png_ptr->chunk_name == png_sBIT) - { - 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 -#ifdef PNG_READ_cHRM_SUPPORTED - else if (png_ptr->chunk_name == png_cHRM) - { - 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 -#ifdef PNG_READ_sRGB_SUPPORTED - else if (chunk_name == png_sRGB) - { - 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 -#ifdef PNG_READ_iCCP_SUPPORTED - else if (png_ptr->chunk_name == png_iCCP) - { - 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 -#ifdef PNG_READ_sPLT_SUPPORTED - else if (chunk_name == png_sPLT) - { - 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 -#ifdef PNG_READ_tRNS_SUPPORTED - else if (chunk_name == png_tRNS) - { - 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 -#ifdef PNG_READ_bKGD_SUPPORTED - else if (chunk_name == png_bKGD) - { - 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 -#ifdef PNG_READ_hIST_SUPPORTED - else if (chunk_name == png_hIST) - { - 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 -#ifdef PNG_READ_pHYs_SUPPORTED - else if (chunk_name == png_pHYs) - { - 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 -#ifdef PNG_READ_oFFs_SUPPORTED - else if (chunk_name == png_oFFs) - { - 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 - -#ifdef PNG_READ_pCAL_SUPPORTED - else if (chunk_name == png_pCAL) - { - 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 -#ifdef PNG_READ_sCAL_SUPPORTED - else if (chunk_name == png_sCAL) - { - 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 -#ifdef PNG_READ_tIME_SUPPORTED - else if (chunk_name == png_tIME) - { - 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 -#ifdef PNG_READ_tEXt_SUPPORTED - else if (chunk_name == png_tEXt) - { - if (png_ptr->push_length + 4 > png_ptr->buffer_size) - { - png_push_save_buffer(png_ptr); - return; - } - - png_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_zTXt_SUPPORTED - else if (chunk_name == png_zTXt) - { - if (png_ptr->push_length + 4 > png_ptr->buffer_size) - { - png_push_save_buffer(png_ptr); - return; - } - - png_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); - } - -#endif -#ifdef PNG_READ_iTXt_SUPPORTED - else if (chunk_name == png_iTXt) - { - if (png_ptr->push_length + 4 > png_ptr->buffer_size) - { - png_push_save_buffer(png_ptr); - return; - } - - png_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_handle_unknown(png_ptr, info_ptr, png_ptr->push_length, - PNG_HANDLE_CHUNK_AS_DEFAULT); - } - - png_ptr->mode &= ~PNG_HAVE_CHUNK_HEADER; -} - -void /* PRIVATE */ -png_push_crc_skip(png_structrp 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_structrp png_ptr) -{ - if (png_ptr->skip_length && png_ptr->save_buffer_size) - { - png_size_t save_size = png_ptr->save_buffer_size; - png_uint_32 skip_length = png_ptr->skip_length; - - /* We want the smaller of 'skip_length' and 'save_buffer_size', but - * they are of different types and we don't know which variable has the - * fewest bits. Carefully select the smaller and cast it to the type of - * the larger - this cannot overflow. Do not cast in the following test - * - it will break on either 16 or 64 bit platforms. - */ - if (skip_length < save_size) - save_size = (png_size_t)skip_length; - - else - skip_length = (png_uint_32)save_size; - - png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); - - png_ptr->skip_length -= skip_length; - 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 = png_ptr->current_buffer_size; - png_uint_32 skip_length = png_ptr->skip_length; - - /* We want the smaller of 'skip_length' and 'current_buffer_size', here, - * the same problem exists as above and the same solution. - */ - if (skip_length < save_size) - save_size = (png_size_t)skip_length; - - else - skip_length = (png_uint_32)save_size; - - png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); - - png_ptr->skip_length -= skip_length; - 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 PNGCBAPI -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; - - 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; - - 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_structrp 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_warn(png_ptr, - (png_size_t)new_max); - - if (png_ptr->save_buffer == NULL) - { - png_free(png_ptr, old_buffer); - png_error(png_ptr, "Insufficient memory for save_buffer"); - } - - 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) - { - 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_structrp 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_structrp png_ptr) -{ - if (!(png_ptr->mode & PNG_HAVE_CHUNK_HEADER)) - { - png_byte chunk_length[4]; - png_byte chunk_tag[4]; - - /* TODO: this code can be commoned up with the same code in push_read */ - 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, chunk_tag, 4); - png_ptr->chunk_name = PNG_CHUNK_FROM_STRING(chunk_tag); - png_ptr->mode |= PNG_HAVE_CHUNK_HEADER; - - if (png_ptr->chunk_name != png_IDAT) - { - png_ptr->process_mode = PNG_READ_CHUNK_MODE; - - if (!(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED)) - 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 = png_ptr->save_buffer_size; - png_uint_32 idat_size = png_ptr->idat_size; - - /* We want the smaller of 'idat_size' and 'current_buffer_size', but they - * are of different types and we don't know which variable has the fewest - * bits. Carefully select the smaller and cast it to the type of the - * larger - this cannot overflow. Do not cast in the following test - it - * will break on either 16 or 64 bit platforms. - */ - if (idat_size < save_size) - save_size = (png_size_t)idat_size; - - else - idat_size = (png_uint_32)save_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 -= idat_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 = png_ptr->current_buffer_size; - png_uint_32 idat_size = png_ptr->idat_size; - - /* We want the smaller of 'idat_size' and 'current_buffer_size', but they - * are of different types and we don't know which variable has the fewest - * bits. Carefully select the smaller and cast it to the type of the - * larger - this cannot overflow. - */ - if (idat_size < save_size) - save_size = (png_size_t)idat_size; - - else - idat_size = (png_uint_32)save_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 -= idat_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; - png_ptr->zowner = 0; - } -} - -void /* PRIVATE */ -png_process_IDAT_data(png_structrp png_ptr, png_bytep buffer, - png_size_t buffer_length) -{ - /* The caller checks for a non-zero buffer length. */ - if (!(buffer_length > 0) || buffer == NULL) - png_error(png_ptr, "No IDAT data (internal error)"); - - /* This routine must process all the data it has been given - * before returning, calling the row callback as required to - * handle the uncompressed results. - */ - png_ptr->zstream.next_in = buffer; - /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */ - png_ptr->zstream.avail_in = (uInt)buffer_length; - - /* Keep going until the decompressed data is all processed - * or the stream marked as finished. - */ - while (png_ptr->zstream.avail_in > 0 && - !(png_ptr->flags & PNG_FLAG_ZSTREAM_ENDED)) - { - int ret; - - /* We have data for zlib, but we must check that zlib - * has someplace to put the results. It doesn't matter - * if we don't expect any results -- it may be the input - * data is just the LZ end code. - */ - if (!(png_ptr->zstream.avail_out > 0)) - { - /* TODO: WARNING: TRUNCATION ERROR: DANGER WILL ROBINSON: */ - png_ptr->zstream.avail_out = (uInt)(PNG_ROWBYTES(png_ptr->pixel_depth, - png_ptr->iwidth) + 1); - - png_ptr->zstream.next_out = png_ptr->row_buf; - } - - /* Using Z_SYNC_FLUSH here means that an unterminated - * LZ stream (a stream with a missing end code) can still - * be handled, otherwise (Z_NO_FLUSH) a future zlib - * implementation might defer output and therefore - * change the current behavior (see comments in inflate.c - * for why this doesn't happen at present with zlib 1.2.5). - */ - ret = inflate(&png_ptr->zstream, Z_SYNC_FLUSH); - - /* Check for any failure before proceeding. */ - if (ret != Z_OK && ret != Z_STREAM_END) - { - /* Terminate the decompression. */ - png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; - png_ptr->zowner = 0; - - /* This may be a truncated stream (missing or - * damaged end code). Treat that as a warning. - */ - if (png_ptr->row_number >= png_ptr->num_rows || - png_ptr->pass > 6) - png_warning(png_ptr, "Truncated compressed data in IDAT"); - - else - png_error(png_ptr, "Decompression error in IDAT"); - - /* Skip the check on unprocessed input */ - return; - } - - /* Did inflate output any data? */ - if (png_ptr->zstream.next_out != png_ptr->row_buf) - { - /* Is this unexpected data after the last row? - * If it is, artificially terminate the LZ output - * here. - */ - if (png_ptr->row_number >= png_ptr->num_rows || - png_ptr->pass > 6) - { - /* Extra data. */ - png_warning(png_ptr, "Extra compressed data in IDAT"); - png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; - png_ptr->zowner = 0; - - /* Do no more processing; skip the unprocessed - * input check below. - */ - return; - } - - /* Do we have a complete row? */ - if (png_ptr->zstream.avail_out == 0) - png_push_process_row(png_ptr); - } - - /* And check for the end of the stream. */ - if (ret == Z_STREAM_END) - png_ptr->flags |= PNG_FLAG_ZSTREAM_ENDED; - } - - /* All the data should have been processed, if anything - * is left at this point we have bytes of IDAT data - * after the zlib end code. - */ - if (png_ptr->zstream.avail_in > 0) - png_warning(png_ptr, "Extra compression data in IDAT"); -} - -void /* PRIVATE */ -png_push_process_row(png_structrp png_ptr) -{ - /* 1.5.6: row_info moved out of png_struct to a local here. */ - png_row_info row_info; - - row_info.width = png_ptr->iwidth; /* NOTE: width of current interlaced row */ - row_info.color_type = png_ptr->color_type; - row_info.bit_depth = png_ptr->bit_depth; - row_info.channels = png_ptr->channels; - row_info.pixel_depth = png_ptr->pixel_depth; - row_info.rowbytes = PNG_ROWBYTES(row_info.pixel_depth, row_info.width); - - if (png_ptr->row_buf[0] > PNG_FILTER_VALUE_NONE) - { - if (png_ptr->row_buf[0] < PNG_FILTER_VALUE_LAST) - png_read_filter_row(png_ptr, &row_info, png_ptr->row_buf + 1, - png_ptr->prev_row + 1, png_ptr->row_buf[0]); - else - png_error(png_ptr, "bad adaptive filter value"); - } - - /* libpng 1.5.6: the following line was copying png_ptr->rowbytes before - * 1.5.6, while the buffer really is this big in current versions of libpng - * it may not be in the future, so this was changed just to copy the - * interlaced row count: - */ - memcpy(png_ptr->prev_row, png_ptr->row_buf, row_info.rowbytes + 1); - -#ifdef PNG_READ_TRANSFORMS_SUPPORTED - if (png_ptr->transformations) - png_do_read_transformations(png_ptr, &row_info); -#endif - - /* The transformed pixel depth should match the depth now in row_info. */ - if (png_ptr->transformed_pixel_depth == 0) - { - png_ptr->transformed_pixel_depth = row_info.pixel_depth; - if (row_info.pixel_depth > png_ptr->maximum_pixel_depth) - png_error(png_ptr, "progressive row overflow"); - } - - else if (png_ptr->transformed_pixel_depth != row_info.pixel_depth) - png_error(png_ptr, "internal progressive row size calculation error"); - - -#ifdef PNG_READ_INTERLACING_SUPPORTED - /* Expand interlaced rows to full size */ - if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) - { - if (png_ptr->pass < 6) - png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass, - png_ptr->transformations); - - 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, 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, NULL); - png_read_push_finish_row(png_ptr); - } - } - - if (png_ptr->pass == 6 && png_ptr->height <= 4) - { - png_push_have_row(png_ptr, 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, 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); - } - - 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, 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, 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); - } - - if (png_ptr->pass == 6) /* Pass 5 might be empty */ - { - 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) /* Skip top generated row */ - { - png_push_have_row(png_ptr, NULL); - png_read_push_finish_row(png_ptr); - } - - break; - } - - default: - 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 - { - 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_structrp png_ptr) -{ - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - static PNG_CONST png_byte png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - static PNG_CONST png_byte png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; - - /* Start of interlace block in the y direction */ - static PNG_CONST png_byte png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; - - /* Offset to next interlace block in the y direction */ - static PNG_CONST png_byte 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 - static PNG_CONST png_byte 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; - memset(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) - 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]; - - 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); - } -} - -void /* PRIVATE */ -png_push_have_info(png_structrp png_ptr, png_inforp info_ptr) -{ - if (png_ptr->info_fn != NULL) - (*(png_ptr->info_fn))(png_ptr, info_ptr); -} - -void /* PRIVATE */ -png_push_have_end(png_structrp png_ptr, png_inforp info_ptr) -{ - if (png_ptr->end_fn != NULL) - (*(png_ptr->end_fn))(png_ptr, info_ptr); -} - -void /* PRIVATE */ -png_push_have_row(png_structrp 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_const_structrp png_ptr, png_bytep old_row, - png_const_bytep new_row) -{ - if (png_ptr == NULL) - return; - - /* new_row is a flag here - if it is NULL then the app callback was called - * from an empty row (see the calls to png_struct::row_fn below), otherwise - * it must be png_ptr->row_buf+1 - */ - if (new_row != NULL) - png_combine_row(png_ptr, old_row, 1/*blocky display*/); -} - -void PNGAPI -png_set_progressive_read_fn(png_structrp 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_const_structrp png_ptr) -{ - if (png_ptr == NULL) - return (NULL); - - return png_ptr->io_ptr; -} -#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ |