| |
| /* pngpread.c - read a png file in push mode |
| |
| libpng 1.0 beta 6 - version 0.96 |
| For conditions of distribution and use, see copyright notice in png.h |
| Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. |
| Copyright (c) 1996, 1997 Andreas Dilger |
| May 12, 1997 |
| */ |
| |
| #define PNG_INTERNAL |
| #include "png.h" |
| |
| #ifdef PNG_PROGRESSIVE_READ_SUPPORTED |
| |
| void |
| 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 |
| 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 |
| 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, whether because they have been |
| * checked by the calling application, or from multiple calls to this routine. |
| */ |
| void |
| 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 += 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 |
| png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) |
| { |
| /* 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->flags & PNG_FLAG_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->flags |= PNG_FLAG_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_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_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_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 |
| else |
| { |
| png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); |
| } |
| |
| png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER; |
| } |
| |
| void |
| 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 |
| 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 |
| 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 |
| 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; |
| png_bytep sp; |
| png_bytep dp; |
| |
| for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer; |
| i < png_ptr->save_buffer_size; |
| i++, sp++, dp++) |
| { |
| *dp = *sp; |
| } |
| } |
| } |
| if (png_ptr->save_buffer_size + png_ptr->current_buffer_size > |
| png_ptr->save_buffer_max) |
| { |
| 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, 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 |
| 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 |
| png_push_read_IDAT(png_structp png_ptr) |
| { |
| if (!(png_ptr->flags & PNG_FLAG_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->flags |= PNG_FLAG_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_ptr->idat_size; |
| else |
| save_size = png_ptr->save_buffer_size; |
| |
| png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); |
| png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size); |
| |
| png_ptr->idat_size -= save_size; |
| png_ptr->buffer_size -= save_size; |
| png_ptr->save_buffer_size -= save_size; |
| png_ptr->save_buffer_ptr += 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_ptr->idat_size; |
| else |
| save_size = png_ptr->current_buffer_size; |
| |
| png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); |
| png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size); |
| |
| png_ptr->idat_size -= save_size; |
| png_ptr->buffer_size -= save_size; |
| png_ptr->current_buffer_size -= save_size; |
| png_ptr->current_buffer_ptr += 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->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER; |
| } |
| } |
| |
| void |
| 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; |
| while(1) |
| { |
| ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); |
| if (ret == Z_STREAM_END) |
| { |
| if (png_ptr->zstream.avail_in) |
| png_error(png_ptr, "Extra compressed data"); |
| if (!(png_ptr->zstream.avail_out)) |
| { |
| png_push_process_row(png_ptr); |
| } |
| |
| png_ptr->mode |= PNG_AFTER_IDAT; |
| png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; |
| break; |
| } |
| else if (ret == Z_BUF_ERROR) |
| break; |
| else if (ret != Z_OK) |
| png_error(png_ptr, "Decompression Error"); |
| if (!(png_ptr->zstream.avail_out)) |
| { |
| png_push_process_row(png_ptr); |
| png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes; |
| png_ptr->zstream.next_out = png_ptr->row_buf; |
| } |
| else |
| break; |
| } |
| } |
| |
| void |
| png_push_process_row(png_structp png_ptr) |
| { |
| png_ptr->row_info.color_type = png_ptr->color_type; |
| png_ptr->row_info.width = png_ptr->iwidth; |
| png_ptr->row_info.channels = png_ptr->channels; |
| png_ptr->row_info.bit_depth = png_ptr->bit_depth; |
| png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; |
| png_ptr->row_info.rowbytes = ((png_ptr->row_info.width * |
| (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3); |
| |
| png_read_filter_row(png_ptr, &(png_ptr->row_info), |
| png_ptr->row_buf + 1, png_ptr->prev_row + 1, |
| (int)(png_ptr->row_buf[0])); |
| |
| png_memcpy(png_ptr->prev_row, png_ptr->row_buf, png_ptr->rowbytes + 1); |
| |
| if (png_ptr->transformations) |
| png_do_read_transformations(png_ptr); |
| |
| #if defined(PNG_READ_INTERLACING_SUPPORTED) |
| /* blow up interlaced rows to full size */ |
| if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) |
| { |
| if (png_ptr->pass < 6) |
| png_do_read_interlace(&(png_ptr->row_info), |
| png_ptr->row_buf + 1, png_ptr->pass, 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); |
| } |
| break; |
| } |
| case 1: |
| { |
| int i; |
| for (i = 0; i < 8 && png_ptr->pass == 1; i++) |
| { |
| png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
| png_read_push_finish_row(png_ptr); |
| } |
| if (png_ptr->pass == 2) |
| { |
| for (i = 0; i < 4 && png_ptr->pass == 2; i++) |
| { |
| png_push_have_row(png_ptr, NULL); |
| png_read_push_finish_row(png_ptr); |
| } |
| } |
| break; |
| } |
| case 2: |
| { |
| int i; |
| for (i = 0; i < 4 && png_ptr->pass == 2; i++) |
| { |
| png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
| png_read_push_finish_row(png_ptr); |
| } |
| for (i = 0; i < 4 && png_ptr->pass == 2; i++) |
| { |
| png_push_have_row(png_ptr, NULL); |
| png_read_push_finish_row(png_ptr); |
| } |
| break; |
| } |
| case 3: |
| { |
| int i; |
| for (i = 0; i < 4 && png_ptr->pass == 3; i++) |
| { |
| png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
| png_read_push_finish_row(png_ptr); |
| } |
| if (png_ptr->pass == 4) |
| { |
| for (i = 0; i < 2 && png_ptr->pass == 4; i++) |
| { |
| png_push_have_row(png_ptr, NULL); |
| png_read_push_finish_row(png_ptr); |
| } |
| } |
| break; |
| } |
| case 4: |
| { |
| int i; |
| for (i = 0; i < 2 && png_ptr->pass == 4; i++) |
| { |
| png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
| png_read_push_finish_row(png_ptr); |
| } |
| for (i = 0; i < 2 && png_ptr->pass == 4; i++) |
| { |
| png_push_have_row(png_ptr, NULL); |
| png_read_push_finish_row(png_ptr); |
| } |
| break; |
| } |
| case 5: |
| { |
| int i; |
| for (i = 0; i < 2 && png_ptr->pass == 5; i++) |
| { |
| png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
| png_read_push_finish_row(png_ptr); |
| } |
| if (png_ptr->pass == 6) |
| { |
| png_push_have_row(png_ptr, NULL); |
| png_read_push_finish_row(png_ptr); |
| } |
| break; |
| } |
| case 6: |
| { |
| png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
| png_read_push_finish_row(png_ptr); |
| if (png_ptr->pass != 6) |
| break; |
| png_push_have_row(png_ptr, NULL); |
| png_read_push_finish_row(png_ptr); |
| } |
| } |
| } |
| else |
| #endif |
| { |
| png_push_have_row(png_ptr, png_ptr->row_buf + 1); |
| png_read_push_finish_row(png_ptr); |
| } |
| } |
| |
| void |
| png_read_push_finish_row(png_structp png_ptr) |
| { |
| png_ptr->row_number++; |
| if (png_ptr->row_number < png_ptr->num_rows) |
| return; |
| |
| if (png_ptr->interlaced) |
| { |
| png_ptr->row_number = 0; |
| png_memset(png_ptr->prev_row, 0, png_ptr->rowbytes + 1); |
| do |
| { |
| png_ptr->pass++; |
| if (png_ptr->pass >= 7) |
| break; |
| png_ptr->iwidth = (png_ptr->width + |
| png_pass_inc[png_ptr->pass] - 1 - |
| png_pass_start[png_ptr->pass]) / |
| png_pass_inc[png_ptr->pass]; |
| png_ptr->irowbytes = ((png_ptr->iwidth * |
| png_ptr->pixel_depth + 7) >> 3) + 1; |
| if (!(png_ptr->transformations & PNG_INTERLACE)) |
| { |
| png_ptr->num_rows = (png_ptr->height + |
| png_pass_yinc[png_ptr->pass] - 1 - |
| png_pass_ystart[png_ptr->pass]) / |
| png_pass_yinc[png_ptr->pass]; |
| if (!(png_ptr->num_rows)) |
| continue; |
| } |
| if (png_ptr->transformations & PNG_INTERLACE) |
| break; |
| } while (png_ptr->iwidth == 0); |
| } |
| } |
| |
| #if defined(PNG_READ_tEXt_SUPPORTED) |
| void |
| png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| { |
| if (png_ptr->mode == PNG_BEFORE_IHDR || png_ptr->mode & PNG_HAVE_IEND) |
| png_error(png_ptr, "Out of place tEXt"); |
| |
| #ifdef PNG_MAX_MALLOC_64K |
| png_ptr->skip_length = 0; /* This may not be necessary */ |
| |
| if (length > 65535L) /* We can't hold the entire string in memory */ |
| { |
| png_warning(png_ptr, "tEXt chunk too large to fit in memory"); |
| png_ptr->skip_length = length - 65535L; |
| length = 65535L; |
| } |
| #endif |
| |
| png_ptr->current_text = (png_charp)png_malloc(png_ptr, length+1); |
| png_ptr->current_text[length] = '\0'; |
| png_ptr->current_text_ptr = png_ptr->current_text; |
| png_ptr->current_text_size = length; |
| png_ptr->current_text_left = length; |
| png_ptr->process_mode = PNG_READ_tEXt_MODE; |
| } |
| |
| void |
| png_push_read_tEXt(png_structp png_ptr, png_infop info_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, sizeof(png_text)); |
| text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; |
| text_ptr->key = key; |
| text_ptr->text = text; |
| |
| png_set_text(png_ptr, info_ptr, text_ptr, 1); |
| |
| png_free(png_ptr, text_ptr); |
| } |
| } |
| #endif |
| |
| #if defined(PNG_READ_zTXt_SUPPORTED) |
| void |
| png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| { |
| if (png_ptr->mode == PNG_BEFORE_IHDR || png_ptr->mode & PNG_HAVE_IEND) |
| png_error(png_ptr, "Out of place zTXt"); |
| |
| #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 > 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, length+1); |
| png_ptr->current_text[length] = '\0'; |
| png_ptr->current_text_ptr = png_ptr->current_text; |
| png_ptr->current_text_size = length; |
| png_ptr->current_text_left = length; |
| png_ptr->process_mode = PNG_READ_zTXt_MODE; |
| } |
| |
| void |
| png_push_read_zTXt(png_structp png_ptr, png_infop info_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 = 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_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_malloc(png_ptr, text_size + |
| 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_size -= key_size; |
| |
| text_ptr = (png_textp)png_malloc(png_ptr, sizeof(png_text)); |
| text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt; |
| text_ptr->key = key; |
| text_ptr->text = 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. In the future we will have code here which can handle |
| user-defined callback functions for unknown chunks before they are |
| ignored or cause an error. 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 |
| png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) |
| { |
| png_check_chunk_name(png_ptr, png_ptr->chunk_name); |
| |
| if (!(png_ptr->chunk_name[0] & 0x20)) |
| { |
| char msg[40]; |
| |
| sprintf(msg, "Unknown critical chunk %s", png_ptr->chunk_name); |
| png_error(png_ptr, msg); |
| } |
| |
| png_push_crc_skip(png_ptr, length); |
| } |
| |
| void |
| 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 |
| 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 |
| 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 |
| png_progressive_combine_row (png_structp png_ptr, |
| png_bytep old_row, png_bytep new_row) |
| { |
| if (new_row != NULL) |
| png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]); |
| } |
| |
| void |
| png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr, |
| png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, |
| png_progressive_end_ptr end_fn) |
| { |
| png_ptr->info_fn = info_fn; |
| png_ptr->row_fn = row_fn; |
| png_ptr->end_fn = end_fn; |
| |
| png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer); |
| } |
| |
| png_voidp |
| png_get_progressive_ptr(png_structp png_ptr) |
| { |
| return png_ptr->io_ptr; |
| } |
| |
| #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ |
| |
