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Diffstat (limited to 'png/pngwutil.c')
| -rw-r--r-- | png/pngwutil.c | 3026 |
1 files changed, 0 insertions, 3026 deletions
diff --git a/png/pngwutil.c b/png/pngwutil.c deleted file mode 100644 index cfc3312..0000000 --- a/png/pngwutil.c +++ /dev/null @@ -1,3026 +0,0 @@ - -/* pngwutil.c - utilities to write a PNG file - * - * 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_WRITE_SUPPORTED - -#ifdef PNG_WRITE_INT_FUNCTIONS_SUPPORTED -/* Place a 32-bit number into a buffer in PNG byte order. We work - * with unsigned numbers for convenience, although one supported - * ancillary chunk uses signed (two's complement) numbers. - */ -void PNGAPI -png_save_uint_32(png_bytep buf, png_uint_32 i) -{ - buf[0] = (png_byte)((i >> 24) & 0xff); - buf[1] = (png_byte)((i >> 16) & 0xff); - buf[2] = (png_byte)((i >> 8) & 0xff); - buf[3] = (png_byte)(i & 0xff); -} - -/* Place a 16-bit number into a buffer in PNG byte order. - * The parameter is declared unsigned int, not png_uint_16, - * just to avoid potential problems on pre-ANSI C compilers. - */ -void PNGAPI -png_save_uint_16(png_bytep buf, unsigned int i) -{ - buf[0] = (png_byte)((i >> 8) & 0xff); - buf[1] = (png_byte)(i & 0xff); -} -#endif - -/* Simple function to write the signature. If we have already written - * the magic bytes of the signature, or more likely, the PNG stream is - * being embedded into another stream and doesn't need its own signature, - * we should call png_set_sig_bytes() to tell libpng how many of the - * bytes have already been written. - */ -void PNGAPI -png_write_sig(png_structrp png_ptr) -{ - png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; - -#ifdef PNG_IO_STATE_SUPPORTED - /* Inform the I/O callback that the signature is being written */ - png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE; -#endif - - /* Write the rest of the 8 byte signature */ - png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes], - (png_size_t)(8 - png_ptr->sig_bytes)); - - if (png_ptr->sig_bytes < 3) - png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE; -} - -/* Write the start of a PNG chunk. The type is the chunk type. - * The total_length is the sum of the lengths of all the data you will be - * passing in png_write_chunk_data(). - */ -static void -png_write_chunk_header(png_structrp png_ptr, png_uint_32 chunk_name, - png_uint_32 length) -{ - png_byte buf[8]; - -#if defined(PNG_DEBUG) && (PNG_DEBUG > 0) - PNG_CSTRING_FROM_CHUNK(buf, chunk_name); - png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length); -#endif - - if (png_ptr == NULL) - return; - -#ifdef PNG_IO_STATE_SUPPORTED - /* Inform the I/O callback that the chunk header is being written. - * PNG_IO_CHUNK_HDR requires a single I/O call. - */ - png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR; -#endif - - /* Write the length and the chunk name */ - png_save_uint_32(buf, length); - png_save_uint_32(buf + 4, chunk_name); - png_write_data(png_ptr, buf, 8); - - /* Put the chunk name into png_ptr->chunk_name */ - png_ptr->chunk_name = chunk_name; - - /* Reset the crc and run it over the chunk name */ - png_reset_crc(png_ptr); - - png_calculate_crc(png_ptr, buf + 4, 4); - -#ifdef PNG_IO_STATE_SUPPORTED - /* Inform the I/O callback that chunk data will (possibly) be written. - * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls. - */ - png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA; -#endif -} - -void PNGAPI -png_write_chunk_start(png_structrp png_ptr, png_const_bytep chunk_string, - png_uint_32 length) -{ - png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length); -} - -/* Write the data of a PNG chunk started with png_write_chunk_header(). - * Note that multiple calls to this function are allowed, and that the - * sum of the lengths from these calls *must* add up to the total_length - * given to png_write_chunk_header(). - */ -void PNGAPI -png_write_chunk_data(png_structrp png_ptr, png_const_bytep data, - png_size_t length) -{ - /* Write the data, and run the CRC over it */ - if (png_ptr == NULL) - return; - - if (data != NULL && length > 0) - { - png_write_data(png_ptr, data, length); - - /* Update the CRC after writing the data, - * in case that the user I/O routine alters it. - */ - png_calculate_crc(png_ptr, data, length); - } -} - -/* Finish a chunk started with png_write_chunk_header(). */ -void PNGAPI -png_write_chunk_end(png_structrp png_ptr) -{ - png_byte buf[4]; - - if (png_ptr == NULL) return; - -#ifdef PNG_IO_STATE_SUPPORTED - /* Inform the I/O callback that the chunk CRC is being written. - * PNG_IO_CHUNK_CRC requires a single I/O function call. - */ - png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC; -#endif - - /* Write the crc in a single operation */ - png_save_uint_32(buf, png_ptr->crc); - - png_write_data(png_ptr, buf, (png_size_t)4); -} - -/* Write a PNG chunk all at once. The type is an array of ASCII characters - * representing the chunk name. The array must be at least 4 bytes in - * length, and does not need to be null terminated. To be safe, pass the - * pre-defined chunk names here, and if you need a new one, define it - * where the others are defined. The length is the length of the data. - * All the data must be present. If that is not possible, use the - * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() - * functions instead. - */ -static void -png_write_complete_chunk(png_structrp png_ptr, png_uint_32 chunk_name, - png_const_bytep data, png_size_t length) -{ - if (png_ptr == NULL) - return; - - /* On 64 bit architectures 'length' may not fit in a png_uint_32. */ - if (length > PNG_UINT_31_MAX) - png_error(png_ptr, "length exceeds PNG maxima"); - - png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length); - png_write_chunk_data(png_ptr, data, length); - png_write_chunk_end(png_ptr); -} - -/* This is the API that calls the internal function above. */ -void PNGAPI -png_write_chunk(png_structrp png_ptr, png_const_bytep chunk_string, - png_const_bytep data, png_size_t length) -{ - png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data, - length); -} - -/* This is used below to find the size of an image to pass to png_deflate_claim, - * so it only needs to be accurate if the size is less than 16384 bytes (the - * point at which a lower LZ window size can be used.) - */ -static png_alloc_size_t -png_image_size(png_structrp png_ptr) -{ - /* Only return sizes up to the maximum of a png_uint_32, do this by limiting - * the width and height used to 15 bits. - */ - png_uint_32 h = png_ptr->height; - - if (png_ptr->rowbytes < 32768 && h < 32768) - { - if (png_ptr->interlaced) - { - /* Interlacing makes the image larger because of the replication of - * both the filter byte and the padding to a byte boundary. - */ - png_uint_32 w = png_ptr->width; - unsigned int pd = png_ptr->pixel_depth; - png_alloc_size_t cb_base; - int pass; - - for (cb_base=0, pass=0; pass<=6; ++pass) - { - png_uint_32 pw = PNG_PASS_COLS(w, pass); - - if (pw > 0) - cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass); - } - - return cb_base; - } - - else - return (png_ptr->rowbytes+1) * h; - } - - else - return 0xffffffffU; -} - -#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED - /* This is the code to hack the first two bytes of the deflate stream (the - * deflate header) to correct the windowBits value to match the actual data - * size. Note that the second argument is the *uncompressed* size but the - * first argument is the *compressed* data (and it must be deflate - * compressed.) - */ -static void -optimize_cmf(png_bytep data, png_alloc_size_t data_size) -{ - /* Optimize the CMF field in the zlib stream. The resultant zlib stream is - * still compliant to the stream specification. - */ - if (data_size <= 16384) /* else windowBits must be 15 */ - { - unsigned int z_cmf = data[0]; /* zlib compression method and flags */ - - if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) - { - unsigned int z_cinfo; - unsigned int half_z_window_size; - - z_cinfo = z_cmf >> 4; - half_z_window_size = 1U << (z_cinfo + 7); - - if (data_size <= half_z_window_size) /* else no change */ - { - unsigned int tmp; - - do - { - half_z_window_size >>= 1; - --z_cinfo; - } - while (z_cinfo > 0 && data_size <= half_z_window_size); - - z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); - - data[0] = (png_byte)z_cmf; - tmp = data[1] & 0xe0; - tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; - data[1] = (png_byte)tmp; - } - } - } -} -#else -# define optimize_cmf(dp,dl) ((void)0) -#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */ - -/* Initialize the compressor for the appropriate type of compression. */ -static int -png_deflate_claim(png_structrp png_ptr, png_uint_32 owner, - png_alloc_size_t data_size) -{ - if (png_ptr->zowner != 0) - { - char msg[64]; - - PNG_STRING_FROM_CHUNK(msg, owner); - msg[4] = ':'; - msg[5] = ' '; - PNG_STRING_FROM_CHUNK(msg+6, png_ptr->zowner); - /* So the message that results is "<chunk> using zstream"; this is an - * internal error, but is very useful for debugging. i18n requirements - * are minimal. - */ - (void)png_safecat(msg, (sizeof msg), 10, " using zstream"); -# if PNG_LIBPNG_BUILD_BASE_TYPE >= PNG_LIBPNG_BUILD_RC - png_warning(png_ptr, msg); - - /* Attempt sane error recovery */ - if (png_ptr->zowner == png_IDAT) /* don't steal from IDAT */ - { - png_ptr->zstream.msg = PNGZ_MSG_CAST("in use by IDAT"); - return Z_STREAM_ERROR; - } - - png_ptr->zowner = 0; -# else - png_error(png_ptr, msg); -# endif - } - - { - int level = png_ptr->zlib_level; - int method = png_ptr->zlib_method; - int windowBits = png_ptr->zlib_window_bits; - int memLevel = png_ptr->zlib_mem_level; - int strategy; /* set below */ - int ret; /* zlib return code */ - - if (owner == png_IDAT) - { - if (png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY) - strategy = png_ptr->zlib_strategy; - - else if (png_ptr->do_filter != PNG_FILTER_NONE) - strategy = PNG_Z_DEFAULT_STRATEGY; - - else - strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY; - } - - else - { -# ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED - level = png_ptr->zlib_text_level; - method = png_ptr->zlib_text_method; - windowBits = png_ptr->zlib_text_window_bits; - memLevel = png_ptr->zlib_text_mem_level; - strategy = png_ptr->zlib_text_strategy; -# else - /* If customization is not supported the values all come from the - * IDAT values except for the strategy, which is fixed to the - * default. (This is the pre-1.6.0 behavior too, although it was - * implemented in a very different way.) - */ - strategy = Z_DEFAULT_STRATEGY; -# endif - } - - /* Adjust 'windowBits' down if larger than 'data_size'; to stop this - * happening just pass 32768 as the data_size parameter. Notice that zlib - * requires an extra 262 bytes in the window in addition to the data to be - * able to see the whole of the data, so if data_size+262 takes us to the - * next windowBits size we need to fix up the value later. (Because even - * though deflate needs the extra window, inflate does not!) - */ - if (data_size <= 16384) - { - /* IMPLEMENTATION NOTE: this 'half_window_size' stuff is only here to - * work round a Microsoft Visual C misbehavior which, contrary to C-90, - * widens the result of the following shift to 64-bits if (and, - * apparently, only if) it is used in a test. - */ - unsigned int half_window_size = 1U << (windowBits-1); - - while (data_size + 262 <= half_window_size) - { - half_window_size >>= 1; - --windowBits; - } - } - - /* Check against the previous initialized values, if any. */ - if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) && - (png_ptr->zlib_set_level != level || - png_ptr->zlib_set_method != method || - png_ptr->zlib_set_window_bits != windowBits || - png_ptr->zlib_set_mem_level != memLevel || - png_ptr->zlib_set_strategy != strategy)) - { - if (deflateEnd(&png_ptr->zstream) != Z_OK) - png_warning(png_ptr, "deflateEnd failed (ignored)"); - - png_ptr->flags &= ~PNG_FLAG_ZSTREAM_INITIALIZED; - } - - /* For safety clear out the input and output pointers (currently zlib - * doesn't use them on Init, but it might in the future). - */ - png_ptr->zstream.next_in = NULL; - png_ptr->zstream.avail_in = 0; - png_ptr->zstream.next_out = NULL; - png_ptr->zstream.avail_out = 0; - - /* Now initialize if required, setting the new parameters, otherwise just - * to a simple reset to the previous parameters. - */ - if (png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) - ret = deflateReset(&png_ptr->zstream); - - else - { - ret = deflateInit2(&png_ptr->zstream, level, method, windowBits, - memLevel, strategy); - - if (ret == Z_OK) - png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED; - } - - /* The return code is from either deflateReset or deflateInit2; they have - * pretty much the same set of error codes. - */ - if (ret == Z_OK) - png_ptr->zowner = owner; - - else - png_zstream_error(png_ptr, ret); - - return ret; - } -} - -/* Clean up (or trim) a linked list of compression buffers. */ -void /* PRIVATE */ -png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp) -{ - png_compression_bufferp list = *listp; - - if (list != NULL) - { - *listp = NULL; - - do - { - png_compression_bufferp next = list->next; - - png_free(png_ptr, list); - list = next; - } - while (list != NULL); - } -} - -#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED -/* This pair of functions encapsulates the operation of (a) compressing a - * text string, and (b) issuing it later as a series of chunk data writes. - * The compression_state structure is shared context for these functions - * set up by the caller to allow access to the relevant local variables. - * - * compression_buffer (new in 1.6.0) is just a linked list of zbuffer_size - * temporary buffers. From 1.6.0 it is retained in png_struct so that it will - * be correctly freed in the event of a write error (previous implementations - * just leaked memory.) - */ -typedef struct -{ - png_const_bytep input; /* The uncompressed input data */ - png_alloc_size_t input_len; /* Its length */ - png_uint_32 output_len; /* Final compressed length */ - png_byte output[1024]; /* First block of output */ -} compression_state; - -static void -png_text_compress_init(compression_state *comp, png_const_bytep input, - png_alloc_size_t input_len) -{ - comp->input = input; - comp->input_len = input_len; - comp->output_len = 0; -} - -/* Compress the data in the compression state input */ -static int -png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name, - compression_state *comp, png_uint_32 prefix_len) -{ - int ret; - - /* To find the length of the output it is necessary to first compress the - * input, the result is buffered rather than using the two-pass algorithm - * that is used on the inflate side; deflate is assumed to be slower and a - * PNG writer is assumed to have more memory available than a PNG reader. - * - * IMPLEMENTATION NOTE: the zlib API deflateBound() can be used to find an - * upper limit on the output size, but it is always bigger than the input - * size so it is likely to be more efficient to use this linked-list - * approach. - */ - ret = png_deflate_claim(png_ptr, chunk_name, comp->input_len); - - if (ret != Z_OK) - return ret; - - /* Set up the compression buffers, we need a loop here to avoid overflowing a - * uInt. Use ZLIB_IO_MAX to limit the input. The output is always limited - * by the output buffer size, so there is no need to check that. Since this - * is ANSI-C we know that an 'int', hence a uInt, is always at least 16 bits - * in size. - */ - { - png_compression_bufferp *end = &png_ptr->zbuffer_list; - png_alloc_size_t input_len = comp->input_len; /* may be zero! */ - png_uint_32 output_len; - - /* zlib updates these for us: */ - png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input); - png_ptr->zstream.avail_in = 0; /* Set below */ - png_ptr->zstream.next_out = comp->output; - png_ptr->zstream.avail_out = (sizeof comp->output); - - output_len = png_ptr->zstream.avail_out; - - do - { - uInt avail_in = ZLIB_IO_MAX; - - if (avail_in > input_len) - avail_in = (uInt)input_len; - - input_len -= avail_in; - - png_ptr->zstream.avail_in = avail_in; - - if (png_ptr->zstream.avail_out == 0) - { - png_compression_buffer *next; - - /* Chunk data is limited to 2^31 bytes in length, so the prefix - * length must be counted here. - */ - if (output_len + prefix_len > PNG_UINT_31_MAX) - { - ret = Z_MEM_ERROR; - break; - } - - /* Need a new (malloc'ed) buffer, but there may be one present - * already. - */ - next = *end; - if (next == NULL) - { - next = png_voidcast(png_compression_bufferp, png_malloc_base - (png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr))); - - if (next == NULL) - { - ret = Z_MEM_ERROR; - break; - } - - /* Link in this buffer (so that it will be freed later) */ - next->next = NULL; - *end = next; - } - - png_ptr->zstream.next_out = next->output; - png_ptr->zstream.avail_out = png_ptr->zbuffer_size; - output_len += png_ptr->zstream.avail_out; - - /* Move 'end' to the next buffer pointer. */ - end = &next->next; - } - - /* Compress the data */ - ret = deflate(&png_ptr->zstream, - input_len > 0 ? Z_NO_FLUSH : Z_FINISH); - - /* Claw back input data that was not consumed (because avail_in is - * reset above every time round the loop). - */ - input_len += png_ptr->zstream.avail_in; - png_ptr->zstream.avail_in = 0; /* safety */ - } - while (ret == Z_OK); - - /* There may be some space left in the last output buffer, this needs to - * be subtracted from output_len. - */ - output_len -= png_ptr->zstream.avail_out; - png_ptr->zstream.avail_out = 0; /* safety */ - comp->output_len = output_len; - - /* Now double check the output length, put in a custom message if it is - * too long. Otherwise ensure the z_stream::msg pointer is set to - * something. - */ - if (output_len + prefix_len >= PNG_UINT_31_MAX) - { - png_ptr->zstream.msg = PNGZ_MSG_CAST("compressed data too long"); - ret = Z_MEM_ERROR; - } - - else - png_zstream_error(png_ptr, ret); - - /* Reset zlib for another zTXt/iTXt or image data */ - png_ptr->zowner = 0; - - /* The only success case is Z_STREAM_END, input_len must be 0, if not this - * is an internal error. - */ - if (ret == Z_STREAM_END && input_len == 0) - { - /* Fix up the deflate header, if required */ - optimize_cmf(comp->output, comp->input_len); - - /* But Z_OK is returned, not Z_STREAM_END; this allows the claim - * function above to return Z_STREAM_END on an error (though it never - * does in the current versions of zlib.) - */ - return Z_OK; - } - - else - return ret; - } -} - -/* Ship the compressed text out via chunk writes */ -static void -png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp) -{ - png_uint_32 output_len = comp->output_len; - png_const_bytep output = comp->output; - png_uint_32 avail = (sizeof comp->output); - png_compression_buffer *next = png_ptr->zbuffer_list; - - for (;;) - { - if (avail > output_len) - avail = output_len; - - png_write_chunk_data(png_ptr, output, avail); - - output_len -= avail; - - if (output_len == 0 || next == NULL) - break; - - avail = png_ptr->zbuffer_size; - output = next->output; - next = next->next; - } - - /* This is an internal error; 'next' must have been NULL! */ - if (output_len > 0) - png_error(png_ptr, "error writing ancillary chunked compressed data"); -} -#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */ - -#if defined(PNG_WRITE_TEXT_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) || \ - defined(PNG_WRITE_iCCP_SUPPORTED) || defined(PNG_WRITE_sPLT_SUPPORTED) -/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification, - * and if invalid, correct the keyword rather than discarding the entire - * chunk. The PNG 1.0 specification requires keywords 1-79 characters in - * length, forbids leading or trailing whitespace, multiple internal spaces, - * and the non-break space (0x80) from ISO 8859-1. Returns keyword length. - * - * The 'new_key' buffer must be 80 characters in size (for the keyword plus a - * trailing '\0'). If this routine returns 0 then there was no keyword, or a - * valid one could not be generated, and the caller must png_error. - */ -static png_uint_32 -png_check_keyword(png_structrp png_ptr, png_const_charp key, png_bytep new_key) -{ - png_const_charp orig_key = key; - png_uint_32 key_len = 0; - int bad_character = 0; - int space = 1; - - png_debug(1, "in png_check_keyword"); - - if (key == NULL) - { - *new_key = 0; - return 0; - } - - while (*key && key_len < 79) - { - png_byte ch = (png_byte)(0xff & *key++); - - if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/)) - *new_key++ = ch, ++key_len, space = 0; - - else if (space == 0) - { - /* A space or an invalid character when one wasn't seen immediately - * before; output just a space. - */ - *new_key++ = 32, ++key_len, space = 1; - - /* If the character was not a space then it is invalid. */ - if (ch != 32) - bad_character = ch; - } - - else if (bad_character == 0) - bad_character = ch; /* just skip it, record the first error */ - } - - if (key_len > 0 && space) /* trailing space */ - { - --key_len, --new_key; - if (bad_character == 0) - bad_character = 32; - } - - /* Terminate the keyword */ - *new_key = 0; - - if (key_len == 0) - return 0; - - /* Try to only output one warning per keyword: */ - if (*key) /* keyword too long */ - png_warning(png_ptr, "keyword truncated"); - - else if (bad_character != 0) - { - PNG_WARNING_PARAMETERS(p) - - png_warning_parameter(p, 1, orig_key); - png_warning_parameter_signed(p, 2, PNG_NUMBER_FORMAT_02x, bad_character); - - png_formatted_warning(png_ptr, p, "keyword \"@1\": bad character '0x@2'"); - } - - return key_len; -} -#endif - -/* Write the IHDR chunk, and update the png_struct with the necessary - * information. Note that the rest of this code depends upon this - * information being correct. - */ -void /* PRIVATE */ -png_write_IHDR(png_structrp png_ptr, png_uint_32 width, png_uint_32 height, - int bit_depth, int color_type, int compression_type, int filter_type, - int interlace_type) -{ - png_byte buf[13]; /* Buffer to store the IHDR info */ - - png_debug(1, "in png_write_IHDR"); - - /* Check that we have valid input data from the application info */ - switch (color_type) - { - case PNG_COLOR_TYPE_GRAY: - switch (bit_depth) - { - case 1: - case 2: - case 4: - case 8: -#ifdef PNG_WRITE_16BIT_SUPPORTED - case 16: -#endif - png_ptr->channels = 1; break; - - default: - png_error(png_ptr, - "Invalid bit depth for grayscale image"); - } - break; - - case PNG_COLOR_TYPE_RGB: -#ifdef PNG_WRITE_16BIT_SUPPORTED - if (bit_depth != 8 && bit_depth != 16) -#else - if (bit_depth != 8) -#endif - png_error(png_ptr, "Invalid bit depth for RGB image"); - - png_ptr->channels = 3; - break; - - case PNG_COLOR_TYPE_PALETTE: - switch (bit_depth) - { - case 1: - case 2: - case 4: - case 8: - png_ptr->channels = 1; - break; - - default: - png_error(png_ptr, "Invalid bit depth for paletted image"); - } - break; - - case PNG_COLOR_TYPE_GRAY_ALPHA: - if (bit_depth != 8 && bit_depth != 16) - png_error(png_ptr, "Invalid bit depth for grayscale+alpha image"); - - png_ptr->channels = 2; - break; - - case PNG_COLOR_TYPE_RGB_ALPHA: -#ifdef PNG_WRITE_16BIT_SUPPORTED - if (bit_depth != 8 && bit_depth != 16) -#else - if (bit_depth != 8) -#endif - png_error(png_ptr, "Invalid bit depth for RGBA image"); - - png_ptr->channels = 4; - break; - - default: - png_error(png_ptr, "Invalid image color type specified"); - } - - if (compression_type != PNG_COMPRESSION_TYPE_BASE) - { - png_warning(png_ptr, "Invalid compression type specified"); - compression_type = PNG_COMPRESSION_TYPE_BASE; - } - - /* Write filter_method 64 (intrapixel differencing) only if - * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and - * 2. Libpng did not write a PNG signature (this filter_method is only - * used in PNG datastreams that are embedded in MNG datastreams) and - * 3. The application called png_permit_mng_features with a mask that - * included PNG_FLAG_MNG_FILTER_64 and - * 4. The filter_method is 64 and - * 5. The color_type is RGB or RGBA - */ - if ( -#ifdef PNG_MNG_FEATURES_SUPPORTED - !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && - ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) && - (color_type == PNG_COLOR_TYPE_RGB || - color_type == PNG_COLOR_TYPE_RGB_ALPHA) && - (filter_type == PNG_INTRAPIXEL_DIFFERENCING)) && -#endif - filter_type != PNG_FILTER_TYPE_BASE) - { - png_warning(png_ptr, "Invalid filter type specified"); - filter_type = PNG_FILTER_TYPE_BASE; - } - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - if (interlace_type != PNG_INTERLACE_NONE && - interlace_type != PNG_INTERLACE_ADAM7) - { - png_warning(png_ptr, "Invalid interlace type specified"); - interlace_type = PNG_INTERLACE_ADAM7; - } -#else - interlace_type=PNG_INTERLACE_NONE; -#endif - - /* Save the relevent information */ - png_ptr->bit_depth = (png_byte)bit_depth; - png_ptr->color_type = (png_byte)color_type; - png_ptr->interlaced = (png_byte)interlace_type; -#ifdef PNG_MNG_FEATURES_SUPPORTED - png_ptr->filter_type = (png_byte)filter_type; -#endif - png_ptr->compression_type = (png_byte)compression_type; - png_ptr->width = width; - png_ptr->height = height; - - png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels); - png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width); - /* Set the usr info, so any transformations can modify it */ - png_ptr->usr_width = png_ptr->width; - png_ptr->usr_bit_depth = png_ptr->bit_depth; - png_ptr->usr_channels = png_ptr->channels; - - /* Pack the header information into the buffer */ - png_save_uint_32(buf, width); - png_save_uint_32(buf + 4, height); - buf[8] = (png_byte)bit_depth; - buf[9] = (png_byte)color_type; - buf[10] = (png_byte)compression_type; - buf[11] = (png_byte)filter_type; - buf[12] = (png_byte)interlace_type; - - /* Write the chunk */ - png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13); - - if ((png_ptr->do_filter) == PNG_NO_FILTERS) - { - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE || - png_ptr->bit_depth < 8) - png_ptr->do_filter = PNG_FILTER_NONE; - - else - png_ptr->do_filter = PNG_ALL_FILTERS; - } - - png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */ -} - -/* Write the palette. We are careful not to trust png_color to be in the - * correct order for PNG, so people can redefine it to any convenient - * structure. - */ -void /* PRIVATE */ -png_write_PLTE(png_structrp png_ptr, png_const_colorp palette, - png_uint_32 num_pal) -{ - png_uint_32 i; - png_const_colorp pal_ptr; - png_byte buf[3]; - - png_debug(1, "in png_write_PLTE"); - - if (( -#ifdef PNG_MNG_FEATURES_SUPPORTED - !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) && -#endif - num_pal == 0) || num_pal > 256) - { - if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) - { - png_error(png_ptr, "Invalid number of colors in palette"); - } - - else - { - png_warning(png_ptr, "Invalid number of colors in palette"); - return; - } - } - - if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR)) - { - png_warning(png_ptr, - "Ignoring request to write a PLTE chunk in grayscale PNG"); - - return; - } - - png_ptr->num_palette = (png_uint_16)num_pal; - png_debug1(3, "num_palette = %d", png_ptr->num_palette); - - png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3)); -#ifdef PNG_POINTER_INDEXING_SUPPORTED - - for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++) - { - buf[0] = pal_ptr->red; - buf[1] = pal_ptr->green; - buf[2] = pal_ptr->blue; - png_write_chunk_data(png_ptr, buf, (png_size_t)3); - } - -#else - /* This is a little slower but some buggy compilers need to do this - * instead - */ - pal_ptr=palette; - - for (i = 0; i < num_pal; i++) - { - buf[0] = pal_ptr[i].red; - buf[1] = pal_ptr[i].green; - buf[2] = pal_ptr[i].blue; - png_write_chunk_data(png_ptr, buf, (png_size_t)3); - } - -#endif - png_write_chunk_end(png_ptr); - png_ptr->mode |= PNG_HAVE_PLTE; -} - -/* This is similar to png_text_compress, above, except that it does not require - * all of the data at once and, instead of buffering the compressed result, - * writes it as IDAT chunks. Unlike png_text_compress it *can* png_error out - * because it calls the write interface. As a result it does its own error - * reporting and does not return an error code. In the event of error it will - * just call png_error. The input data length may exceed 32-bits. The 'flush' - * parameter is exactly the same as that to deflate, with the following - * meanings: - * - * Z_NO_FLUSH: normal incremental output of compressed data - * Z_SYNC_FLUSH: do a SYNC_FLUSH, used by png_write_flush - * Z_FINISH: this is the end of the input, do a Z_FINISH and clean up - * - * The routine manages the acquire and release of the png_ptr->zstream by - * checking and (at the end) clearing png_ptr->zowner, it does some sanity - * checks on the 'mode' flags while doing this. - */ -void /* PRIVATE */ -png_compress_IDAT(png_structrp png_ptr, png_const_bytep input, - png_alloc_size_t input_len, int flush) -{ - if (png_ptr->zowner != png_IDAT) - { - /* First time. Ensure we have a temporary buffer for compression and - * trim the buffer list if it has more than one entry to free memory. - * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been - * created at this point, but the check here is quick and safe. - */ - if (png_ptr->zbuffer_list == NULL) - { - png_ptr->zbuffer_list = png_voidcast(png_compression_bufferp, - png_malloc(png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr))); - png_ptr->zbuffer_list->next = NULL; - } - - else - png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list->next); - - /* It is a terminal error if we can't claim the zstream. */ - if (png_deflate_claim(png_ptr, png_IDAT, png_image_size(png_ptr)) != Z_OK) - png_error(png_ptr, png_ptr->zstream.msg); - - /* The output state is maintained in png_ptr->zstream, so it must be - * initialized here after the claim. - */ - png_ptr->zstream.next_out = png_ptr->zbuffer_list->output; - png_ptr->zstream.avail_out = png_ptr->zbuffer_size; - } - - /* Now loop reading and writing until all the input is consumed or an error - * terminates the operation. The _out values are maintained across calls to - * this function, but the input must be reset each time. - */ - png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input); - png_ptr->zstream.avail_in = 0; /* set below */ - for (;;) - { - int ret; - - /* INPUT: from the row data */ - uInt avail = ZLIB_IO_MAX; - - if (avail > input_len) - avail = (uInt)input_len; /* safe because of the check */ - - png_ptr->zstream.avail_in = avail; - input_len -= avail; - - ret = deflate(&png_ptr->zstream, input_len > 0 ? Z_NO_FLUSH : flush); - - /* Include as-yet unconsumed input */ - input_len += png_ptr->zstream.avail_in; - png_ptr->zstream.avail_in = 0; - - /* OUTPUT: write complete IDAT chunks when avail_out drops to zero, note - * that these two zstream fields are preserved across the calls, therefore - * there is no need to set these up on entry to the loop. - */ - if (png_ptr->zstream.avail_out == 0) - { - png_bytep data = png_ptr->zbuffer_list->output; - uInt size = png_ptr->zbuffer_size; - - /* Write an IDAT containing the data then reset the buffer. The - * first IDAT may need deflate header optimization. - */ -# ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED - if (!(png_ptr->mode & PNG_HAVE_IDAT) && - png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) - optimize_cmf(data, png_image_size(png_ptr)); -# endif - - png_write_complete_chunk(png_ptr, png_IDAT, data, size); - png_ptr->mode |= PNG_HAVE_IDAT; - - png_ptr->zstream.next_out = data; - png_ptr->zstream.avail_out = size; - - /* For SYNC_FLUSH or FINISH it is essential to keep calling zlib with - * the same flush parameter until it has finished output, for NO_FLUSH - * it doesn't matter. - */ - if (ret == Z_OK && flush != Z_NO_FLUSH) - continue; - } - - /* The order of these checks doesn't matter much; it just effect which - * possible error might be detected if multiple things go wrong at once. - */ - if (ret == Z_OK) /* most likely return code! */ - { - /* If all the input has been consumed then just return. If Z_FINISH - * was used as the flush parameter something has gone wrong if we get - * here. - */ - if (input_len == 0) - { - if (flush == Z_FINISH) - png_error(png_ptr, "Z_OK on Z_FINISH with output space"); - - return; - } - } - - else if (ret == Z_STREAM_END && flush == Z_FINISH) - { - /* This is the end of the IDAT data; any pending output must be - * flushed. For small PNG files we may still be at the beginning. - */ - png_bytep data = png_ptr->zbuffer_list->output; - uInt size = png_ptr->zbuffer_size - png_ptr->zstream.avail_out; - -# ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED - if (!(png_ptr->mode & PNG_HAVE_IDAT) && - png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) - optimize_cmf(data, png_image_size(png_ptr)); -# endif - - png_write_complete_chunk(png_ptr, png_IDAT, data, size); - png_ptr->zstream.avail_out = 0; - png_ptr->zstream.next_out = NULL; - png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT; - - png_ptr->zowner = 0; /* Release the stream */ - return; - } - - else - { - /* This is an error condition. */ - png_zstream_error(png_ptr, ret); - png_error(png_ptr, png_ptr->zstream.msg); - } - } -} - -/* Write an IEND chunk */ -void /* PRIVATE */ -png_write_IEND(png_structrp png_ptr) -{ - png_debug(1, "in png_write_IEND"); - - png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0); - png_ptr->mode |= PNG_HAVE_IEND; -} - -#ifdef PNG_WRITE_gAMA_SUPPORTED -/* Write a gAMA chunk */ -void /* PRIVATE */ -png_write_gAMA_fixed(png_structrp png_ptr, png_fixed_point file_gamma) -{ - png_byte buf[4]; - - png_debug(1, "in png_write_gAMA"); - - /* file_gamma is saved in 1/100,000ths */ - png_save_uint_32(buf, (png_uint_32)file_gamma); - png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4); -} -#endif - -#ifdef PNG_WRITE_sRGB_SUPPORTED -/* Write a sRGB chunk */ -void /* PRIVATE */ -png_write_sRGB(png_structrp png_ptr, int srgb_intent) -{ - png_byte buf[1]; - - png_debug(1, "in png_write_sRGB"); - - if (srgb_intent >= PNG_sRGB_INTENT_LAST) - png_warning(png_ptr, - "Invalid sRGB rendering intent specified"); - - buf[0]=(png_byte)srgb_intent; - png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1); -} -#endif - -#ifdef PNG_WRITE_iCCP_SUPPORTED -/* Write an iCCP chunk */ -void /* PRIVATE */ -png_write_iCCP(png_structrp png_ptr, png_const_charp name, - png_const_bytep profile) -{ - png_uint_32 name_len; - png_uint_32 profile_len; - png_byte new_name[81]; /* 1 byte for the compression byte */ - compression_state comp; - png_uint_32 temp; - - png_debug(1, "in png_write_iCCP"); - - /* These are all internal problems: the profile should have been checked - * before when it was stored. - */ - if (profile == NULL) - png_error(png_ptr, "No profile for iCCP chunk"); /* internal error */ - - profile_len = png_get_uint_32(profile); - - if (profile_len < 132) - png_error(png_ptr, "ICC profile too short"); - - temp = (png_uint_32) (*(profile+8)); - if (temp > 3 && (profile_len & 0x03)) - png_error(png_ptr, "ICC profile length invalid (not a multiple of 4)"); - - { - png_uint_32 embedded_profile_len = png_get_uint_32(profile); - - if (profile_len != embedded_profile_len) - png_error(png_ptr, "Profile length does not match profile"); - } - - name_len = png_check_keyword(png_ptr, name, new_name); - - if (name_len == 0) - png_error(png_ptr, "iCCP: invalid keyword"); - - new_name[++name_len] = PNG_COMPRESSION_TYPE_BASE; - - /* Make sure we include the NULL after the name and the compression type */ - ++name_len; - - png_text_compress_init(&comp, profile, profile_len); - - /* Allow for keyword terminator and compression byte */ - if (png_text_compress(png_ptr, png_iCCP, &comp, name_len) != Z_OK) - png_error(png_ptr, png_ptr->zstream.msg); - - png_write_chunk_header(png_ptr, png_iCCP, name_len + comp.output_len); - - png_write_chunk_data(png_ptr, new_name, name_len); - - png_write_compressed_data_out(png_ptr, &comp); - - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_sPLT_SUPPORTED -/* Write a sPLT chunk */ -void /* PRIVATE */ -png_write_sPLT(png_structrp png_ptr, png_const_sPLT_tp spalette) -{ - png_uint_32 name_len; - png_byte new_name[80]; - png_byte entrybuf[10]; - png_size_t entry_size = (spalette->depth == 8 ? 6 : 10); - png_size_t palette_size = entry_size * spalette->nentries; - png_sPLT_entryp ep; -#ifndef PNG_POINTER_INDEXING_SUPPORTED - int i; -#endif - - png_debug(1, "in png_write_sPLT"); - - name_len = png_check_keyword(png_ptr, spalette->name, new_name); - - if (name_len == 0) - png_error(png_ptr, "sPLT: invalid keyword"); - - /* Make sure we include the NULL after the name */ - png_write_chunk_header(png_ptr, png_sPLT, - (png_uint_32)(name_len + 2 + palette_size)); - - png_write_chunk_data(png_ptr, (png_bytep)new_name, - (png_size_t)(name_len + 1)); - - png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1); - - /* Loop through each palette entry, writing appropriately */ -#ifdef PNG_POINTER_INDEXING_SUPPORTED - for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++) - { - if (spalette->depth == 8) - { - entrybuf[0] = (png_byte)ep->red; - entrybuf[1] = (png_byte)ep->green; - entrybuf[2] = (png_byte)ep->blue; - entrybuf[3] = (png_byte)ep->alpha; - png_save_uint_16(entrybuf + 4, ep->frequency); - } - - else - { - png_save_uint_16(entrybuf + 0, ep->red); - png_save_uint_16(entrybuf + 2, ep->green); - png_save_uint_16(entrybuf + 4, ep->blue); - png_save_uint_16(entrybuf + 6, ep->alpha); - png_save_uint_16(entrybuf + 8, ep->frequency); - } - - png_write_chunk_data(png_ptr, entrybuf, entry_size); - } -#else - ep=spalette->entries; - for (i = 0; i>spalette->nentries; i++) - { - if (spalette->depth == 8) - { - entrybuf[0] = (png_byte)ep[i].red; - entrybuf[1] = (png_byte)ep[i].green; - entrybuf[2] = (png_byte)ep[i].blue; - entrybuf[3] = (png_byte)ep[i].alpha; - png_save_uint_16(entrybuf + 4, ep[i].frequency); - } - - else - { - png_save_uint_16(entrybuf + 0, ep[i].red); - png_save_uint_16(entrybuf + 2, ep[i].green); - png_save_uint_16(entrybuf + 4, ep[i].blue); - png_save_uint_16(entrybuf + 6, ep[i].alpha); - png_save_uint_16(entrybuf + 8, ep[i].frequency); - } - - png_write_chunk_data(png_ptr, entrybuf, entry_size); - } -#endif - - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_sBIT_SUPPORTED -/* Write the sBIT chunk */ -void /* PRIVATE */ -png_write_sBIT(png_structrp png_ptr, png_const_color_8p sbit, int color_type) -{ - png_byte buf[4]; - png_size_t size; - - png_debug(1, "in png_write_sBIT"); - - /* Make sure we don't depend upon the order of PNG_COLOR_8 */ - if (color_type & PNG_COLOR_MASK_COLOR) - { - png_byte maxbits; - - maxbits = (png_byte)(color_type==PNG_COLOR_TYPE_PALETTE ? 8 : - png_ptr->usr_bit_depth); - - if (sbit->red == 0 || sbit->red > maxbits || - sbit->green == 0 || sbit->green > maxbits || - sbit->blue == 0 || sbit->blue > maxbits) - { - png_warning(png_ptr, "Invalid sBIT depth specified"); - return; - } - - buf[0] = sbit->red; - buf[1] = sbit->green; - buf[2] = sbit->blue; - size = 3; - } - - else - { - if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth) - { - png_warning(png_ptr, "Invalid sBIT depth specified"); - return; - } - - buf[0] = sbit->gray; - size = 1; - } - - if (color_type & PNG_COLOR_MASK_ALPHA) - { - if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth) - { - png_warning(png_ptr, "Invalid sBIT depth specified"); - return; - } - - buf[size++] = sbit->alpha; - } - - png_write_complete_chunk(png_ptr, png_sBIT, buf, size); -} -#endif - -#ifdef PNG_WRITE_cHRM_SUPPORTED -/* Write the cHRM chunk */ -void /* PRIVATE */ -png_write_cHRM_fixed(png_structrp png_ptr, const png_xy *xy) -{ - png_byte buf[32]; - - png_debug(1, "in png_write_cHRM"); - - /* Each value is saved in 1/100,000ths */ - png_save_int_32(buf, xy->whitex); - png_save_int_32(buf + 4, xy->whitey); - - png_save_int_32(buf + 8, xy->redx); - png_save_int_32(buf + 12, xy->redy); - - png_save_int_32(buf + 16, xy->greenx); - png_save_int_32(buf + 20, xy->greeny); - - png_save_int_32(buf + 24, xy->bluex); - png_save_int_32(buf + 28, xy->bluey); - - png_write_complete_chunk(png_ptr, png_cHRM, buf, 32); -} -#endif - -#ifdef PNG_WRITE_tRNS_SUPPORTED -/* Write the tRNS chunk */ -void /* PRIVATE */ -png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha, - png_const_color_16p tran, int num_trans, int color_type) -{ - png_byte buf[6]; - - png_debug(1, "in png_write_tRNS"); - - if (color_type == PNG_COLOR_TYPE_PALETTE) - { - if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette) - { - png_app_warning(png_ptr, - "Invalid number of transparent colors specified"); - return; - } - - /* Write the chunk out as it is */ - png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha, - (png_size_t)num_trans); - } - - else if (color_type == PNG_COLOR_TYPE_GRAY) - { - /* One 16 bit value */ - if (tran->gray >= (1 << png_ptr->bit_depth)) - { - png_app_warning(png_ptr, - "Ignoring attempt to write tRNS chunk out-of-range for bit_depth"); - - return; - } - - png_save_uint_16(buf, tran->gray); - png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2); - } - - else if (color_type == PNG_COLOR_TYPE_RGB) - { - /* Three 16 bit values */ - png_save_uint_16(buf, tran->red); - png_save_uint_16(buf + 2, tran->green); - png_save_uint_16(buf + 4, tran->blue); -#ifdef PNG_WRITE_16BIT_SUPPORTED - if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) -#else - if (buf[0] | buf[2] | buf[4]) -#endif - { - png_app_warning(png_ptr, - "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8"); - return; - } - - png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6); - } - - else - { - png_app_warning(png_ptr, "Can't write tRNS with an alpha channel"); - } -} -#endif - -#ifdef PNG_WRITE_bKGD_SUPPORTED -/* Write the background chunk */ -void /* PRIVATE */ -png_write_bKGD(png_structrp png_ptr, png_const_color_16p back, int color_type) -{ - png_byte buf[6]; - - png_debug(1, "in png_write_bKGD"); - - if (color_type == PNG_COLOR_TYPE_PALETTE) - { - if ( -#ifdef PNG_MNG_FEATURES_SUPPORTED - (png_ptr->num_palette || - (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) && -#endif - back->index >= png_ptr->num_palette) - { - png_warning(png_ptr, "Invalid background palette index"); - return; - } - - buf[0] = back->index; - png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1); - } - - else if (color_type & PNG_COLOR_MASK_COLOR) - { - png_save_uint_16(buf, back->red); - png_save_uint_16(buf + 2, back->green); - png_save_uint_16(buf + 4, back->blue); -#ifdef PNG_WRITE_16BIT_SUPPORTED - if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4])) -#else - if (buf[0] | buf[2] | buf[4]) -#endif - { - png_warning(png_ptr, - "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8"); - - return; - } - - png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6); - } - - else - { - if (back->gray >= (1 << png_ptr->bit_depth)) - { - png_warning(png_ptr, - "Ignoring attempt to write bKGD chunk out-of-range for bit_depth"); - - return; - } - - png_save_uint_16(buf, back->gray); - png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2); - } -} -#endif - -#ifdef PNG_WRITE_hIST_SUPPORTED -/* Write the histogram */ -void /* PRIVATE */ -png_write_hIST(png_structrp png_ptr, png_const_uint_16p hist, int num_hist) -{ - int i; - png_byte buf[3]; - - png_debug(1, "in png_write_hIST"); - - if (num_hist > (int)png_ptr->num_palette) - { - png_debug2(3, "num_hist = %d, num_palette = %d", num_hist, - png_ptr->num_palette); - - png_warning(png_ptr, "Invalid number of histogram entries specified"); - return; - } - - png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2)); - - for (i = 0; i < num_hist; i++) - { - png_save_uint_16(buf, hist[i]); - png_write_chunk_data(png_ptr, buf, (png_size_t)2); - } - - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_tEXt_SUPPORTED -/* Write a tEXt chunk */ -void /* PRIVATE */ -png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text, - png_size_t text_len) -{ - png_uint_32 key_len; - png_byte new_key[80]; - - png_debug(1, "in png_write_tEXt"); - - key_len = png_check_keyword(png_ptr, key, new_key); - - if (key_len == 0) - png_error(png_ptr, "tEXt: invalid keyword"); - - if (text == NULL || *text == '\0') - text_len = 0; - - else - text_len = strlen(text); - - if (text_len > PNG_UINT_31_MAX - (key_len+1)) - png_error(png_ptr, "tEXt: text too long"); - - /* Make sure we include the 0 after the key */ - png_write_chunk_header(png_ptr, png_tEXt, - (png_uint_32)/*checked above*/(key_len + text_len + 1)); - /* - * We leave it to the application to meet PNG-1.0 requirements on the - * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of - * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them. - * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. - */ - png_write_chunk_data(png_ptr, new_key, key_len + 1); - - if (text_len != 0) - png_write_chunk_data(png_ptr, (png_const_bytep)text, text_len); - - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_zTXt_SUPPORTED -/* Write a compressed text chunk */ -void /* PRIVATE */ -png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text, - png_size_t text_len, int compression) -{ - png_uint_32 key_len; - png_byte new_key[81]; - compression_state comp; - - png_debug(1, "in png_write_zTXt"); - PNG_UNUSED(text_len) /* Always use strlen */ - - if (compression == PNG_TEXT_COMPRESSION_NONE) - { - png_write_tEXt(png_ptr, key, text, 0); - return; - } - - if (compression != PNG_TEXT_COMPRESSION_zTXt) - png_error(png_ptr, "zTXt: invalid compression type"); - - key_len = png_check_keyword(png_ptr, key, new_key); - - if (key_len == 0) - png_error(png_ptr, "zTXt: invalid keyword"); - - /* Add the compression method and 1 for the keyword separator. */ - new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE; - ++key_len; - - /* Compute the compressed data; do it now for the length */ - png_text_compress_init(&comp, (png_const_bytep)text, - text == NULL ? 0 : strlen(text)); - - if (png_text_compress(png_ptr, png_zTXt, &comp, key_len) != Z_OK) - png_error(png_ptr, png_ptr->zstream.msg); - - /* Write start of chunk */ - png_write_chunk_header(png_ptr, png_zTXt, key_len + comp.output_len); - - /* Write key */ - png_write_chunk_data(png_ptr, new_key, key_len); - - /* Write the compressed data */ - png_write_compressed_data_out(png_ptr, &comp); - - /* Close the chunk */ - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_iTXt_SUPPORTED -/* Write an iTXt chunk */ -void /* PRIVATE */ -png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key, - png_const_charp lang, png_const_charp lang_key, png_const_charp text) -{ - png_uint_32 key_len, prefix_len; - png_size_t lang_len, lang_key_len; - png_byte new_key[82]; - compression_state comp; - - png_debug(1, "in png_write_iTXt"); - - key_len = png_check_keyword(png_ptr, key, new_key); - - if (key_len == 0) - png_error(png_ptr, "iTXt: invalid keyword"); - - /* Set the compression flag */ - switch (compression) - { - case PNG_ITXT_COMPRESSION_NONE: - case PNG_TEXT_COMPRESSION_NONE: - compression = new_key[++key_len] = 0; /* no compression */ - break; - - case PNG_TEXT_COMPRESSION_zTXt: - case PNG_ITXT_COMPRESSION_zTXt: - compression = new_key[++key_len] = 1; /* compressed */ - break; - - default: - png_error(png_ptr, "iTXt: invalid compression"); - } - - new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE; - ++key_len; /* for the keywod separator */ - - /* We leave it to the application to meet PNG-1.0 requirements on the - * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of - * any non-Latin-1 characters except for NEWLINE. ISO PNG, however, - * specifies that the text is UTF-8 and this really doesn't require any - * checking. - * - * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG. - * - * TODO: validate the language tag correctly (see the spec.) - */ - if (lang == NULL) lang = ""; /* empty language is valid */ - lang_len = strlen(lang)+1; - if (lang_key == NULL) lang_key = ""; /* may be empty */ - lang_key_len = strlen(lang_key)+1; - if (text == NULL) text = ""; /* may be empty */ - - prefix_len = key_len; - if (lang_len > PNG_UINT_31_MAX-prefix_len) - prefix_len = PNG_UINT_31_MAX; - else - prefix_len = (png_uint_32)(prefix_len + lang_len); - - if (lang_key_len > PNG_UINT_31_MAX-prefix_len) - prefix_len = PNG_UINT_31_MAX; - else - prefix_len = (png_uint_32)(prefix_len + lang_key_len); - - png_text_compress_init(&comp, (png_const_bytep)text, strlen(text)); - - if (compression != 0) - { - if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK) - png_error(png_ptr, png_ptr->zstream.msg); - } - - else - { - if (comp.input_len > PNG_UINT_31_MAX-prefix_len) - png_error(png_ptr, "iTXt: uncompressed text too long"); - - /* So the string will fit in a chunk: */ - comp.output_len = (png_uint_32)/*SAFE*/comp.input_len; - } - - png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len); - - png_write_chunk_data(png_ptr, new_key, key_len); - - png_write_chunk_data(png_ptr, (png_const_bytep)lang, lang_len); - - png_write_chunk_data(png_ptr, (png_const_bytep)lang_key, lang_key_len); - - if (compression != 0) - png_write_compressed_data_out(png_ptr, &comp); - - else - png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.input_len); - - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_oFFs_SUPPORTED -/* Write the oFFs chunk */ -void /* PRIVATE */ -png_write_oFFs(png_structrp png_ptr, png_int_32 x_offset, png_int_32 y_offset, - int unit_type) -{ - png_byte buf[9]; - - png_debug(1, "in png_write_oFFs"); - - if (unit_type >= PNG_OFFSET_LAST) - png_warning(png_ptr, "Unrecognized unit type for oFFs chunk"); - - png_save_int_32(buf, x_offset); - png_save_int_32(buf + 4, y_offset); - buf[8] = (png_byte)unit_type; - - png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9); -} -#endif -#ifdef PNG_WRITE_pCAL_SUPPORTED -/* Write the pCAL chunk (described in the PNG extensions document) */ -void /* PRIVATE */ -png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0, - png_int_32 X1, int type, int nparams, png_const_charp units, - png_charpp params) -{ - png_uint_32 purpose_len; - png_size_t units_len, total_len; - png_size_tp params_len; - png_byte buf[10]; - png_byte new_purpose[80]; - int i; - - png_debug1(1, "in png_write_pCAL (%d parameters)", nparams); - - if (type >= PNG_EQUATION_LAST) - png_error(png_ptr, "Unrecognized equation type for pCAL chunk"); - - purpose_len = png_check_keyword(png_ptr, purpose, new_purpose); - - if (purpose_len == 0) - png_error(png_ptr, "pCAL: invalid keyword"); - - ++purpose_len; /* terminator */ - - png_debug1(3, "pCAL purpose length = %d", (int)purpose_len); - units_len = strlen(units) + (nparams == 0 ? 0 : 1); - png_debug1(3, "pCAL units length = %d", (int)units_len); - total_len = purpose_len + units_len + 10; - - params_len = (png_size_tp)png_malloc(png_ptr, - (png_alloc_size_t)(nparams * (sizeof (png_size_t)))); - - /* Find the length of each parameter, making sure we don't count the - * null terminator for the last parameter. - */ - for (i = 0; i < nparams; i++) - { - params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1); - png_debug2(3, "pCAL parameter %d length = %lu", i, - (unsigned long)params_len[i]); - total_len += params_len[i]; - } - - png_debug1(3, "pCAL total length = %d", (int)total_len); - png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len); - png_write_chunk_data(png_ptr, new_purpose, purpose_len); - png_save_int_32(buf, X0); - png_save_int_32(buf + 4, X1); - buf[8] = (png_byte)type; - buf[9] = (png_byte)nparams; - png_write_chunk_data(png_ptr, buf, (png_size_t)10); - png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len); - - for (i = 0; i < nparams; i++) - { - png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]); - } - - png_free(png_ptr, params_len); - png_write_chunk_end(png_ptr); -} -#endif - -#ifdef PNG_WRITE_sCAL_SUPPORTED -/* Write the sCAL chunk */ -void /* PRIVATE */ -png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width, - png_const_charp height) -{ - png_byte buf[64]; - png_size_t wlen, hlen, total_len; - - png_debug(1, "in png_write_sCAL_s"); - - wlen = strlen(width); - hlen = strlen(height); - total_len = wlen + hlen + 2; - - if (total_len > 64) - { - png_warning(png_ptr, "Can't write sCAL (buffer too small)"); - return; - } - - buf[0] = (png_byte)unit; - memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */ - memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */ - - png_debug1(3, "sCAL total length = %u", (unsigned int)total_len); - png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len); -} -#endif - -#ifdef PNG_WRITE_pHYs_SUPPORTED -/* Write the pHYs chunk */ -void /* PRIVATE */ -png_write_pHYs(png_structrp png_ptr, png_uint_32 x_pixels_per_unit, - png_uint_32 y_pixels_per_unit, - int unit_type) -{ - png_byte buf[9]; - - png_debug(1, "in png_write_pHYs"); - - if (unit_type >= PNG_RESOLUTION_LAST) - png_warning(png_ptr, "Unrecognized unit type for pHYs chunk"); - - png_save_uint_32(buf, x_pixels_per_unit); - png_save_uint_32(buf + 4, y_pixels_per_unit); - buf[8] = (png_byte)unit_type; - - png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9); -} -#endif - -#ifdef PNG_WRITE_tIME_SUPPORTED -/* Write the tIME chunk. Use either png_convert_from_struct_tm() - * or png_convert_from_time_t(), or fill in the structure yourself. - */ -void /* PRIVATE */ -png_write_tIME(png_structrp png_ptr, png_const_timep mod_time) -{ - png_byte buf[7]; - - png_debug(1, "in png_write_tIME"); - - if (mod_time->month > 12 || mod_time->month < 1 || - mod_time->day > 31 || mod_time->day < 1 || - mod_time->hour > 23 || mod_time->second > 60) - { - png_warning(png_ptr, "Invalid time specified for tIME chunk"); - return; - } - - png_save_uint_16(buf, mod_time->year); - buf[2] = mod_time->month; - buf[3] = mod_time->day; - buf[4] = mod_time->hour; - buf[5] = mod_time->minute; - buf[6] = mod_time->second; - - png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7); -} -#endif - -/* Initializes the row writing capability of libpng */ -void /* PRIVATE */ -png_write_start_row(png_structrp png_ptr) -{ -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - - /* Start of interlace block in the y direction */ - static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; - - /* Offset to next interlace block in the y direction */ - static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; -#endif - - png_alloc_size_t buf_size; - int usr_pixel_depth; - - png_debug(1, "in png_write_start_row"); - - usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth; - buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1; - - /* 1.5.6: added to allow checking in the row write code. */ - png_ptr->transformed_pixel_depth = png_ptr->pixel_depth; - png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth; - - /* Set up row buffer */ - png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, buf_size); - - png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE; - -#ifdef PNG_WRITE_FILTER_SUPPORTED - /* Set up filtering buffer, if using this filter */ - if (png_ptr->do_filter & PNG_FILTER_SUB) - { - png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, png_ptr->rowbytes + 1); - - png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB; - } - - /* We only need to keep the previous row if we are using one of these. */ - if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) - { - /* Set up previous row buffer */ - png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, buf_size); - - if (png_ptr->do_filter & PNG_FILTER_UP) - { - png_ptr->up_row = (png_bytep)png_malloc(png_ptr, - png_ptr->rowbytes + 1); - - png_ptr->up_row[0] = PNG_FILTER_VALUE_UP; - } - - if (png_ptr->do_filter & PNG_FILTER_AVG) - { - png_ptr->avg_row = (png_bytep)png_malloc(png_ptr, - png_ptr->rowbytes + 1); - - png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG; - } - - if (png_ptr->do_filter & PNG_FILTER_PAETH) - { - png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr, - png_ptr->rowbytes + 1); - - png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; - } - } -#endif /* PNG_WRITE_FILTER_SUPPORTED */ - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* If interlaced, we need to set up width and height of pass */ - if (png_ptr->interlaced) - { - if (!(png_ptr->transformations & PNG_INTERLACE)) - { - png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - - png_pass_ystart[0]) / png_pass_yinc[0]; - - png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 - - png_pass_start[0]) / png_pass_inc[0]; - } - - else - { - png_ptr->num_rows = png_ptr->height; - png_ptr->usr_width = png_ptr->width; - } - } - - else -#endif - { - png_ptr->num_rows = png_ptr->height; - png_ptr->usr_width = png_ptr->width; - } -} - -/* Internal use only. Called when finished processing a row of data. */ -void /* PRIVATE */ -png_write_finish_row(png_structrp png_ptr) -{ -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - - /* Start of interlace block in the y direction */ - static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; - - /* Offset to next interlace block in the y direction */ - static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; -#endif - - png_debug(1, "in png_write_finish_row"); - - /* Next row */ - png_ptr->row_number++; - - /* See if we are done */ - if (png_ptr->row_number < png_ptr->num_rows) - return; - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED - /* If interlaced, go to next pass */ - if (png_ptr->interlaced) - { - png_ptr->row_number = 0; - if (png_ptr->transformations & PNG_INTERLACE) - { - png_ptr->pass++; - } - - else - { - /* Loop until we find a non-zero width or height pass */ - do - { - png_ptr->pass++; - - if (png_ptr->pass >= 7) - break; - - png_ptr->usr_width = (png_ptr->width + - png_pass_inc[png_ptr->pass] - 1 - - png_pass_start[png_ptr->pass]) / - png_pass_inc[png_ptr->pass]; - - 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->transformations & PNG_INTERLACE) - break; - - } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0); - - } - - /* Reset the row above the image for the next pass */ - if (png_ptr->pass < 7) - { - if (png_ptr->prev_row != NULL) - memset(png_ptr->prev_row, 0, - (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels* - png_ptr->usr_bit_depth, png_ptr->width)) + 1); - - return; - } - } -#endif - - /* If we get here, we've just written the last row, so we need - to flush the compressor */ - png_compress_IDAT(png_ptr, NULL, 0, Z_FINISH); -} - -#ifdef PNG_WRITE_INTERLACING_SUPPORTED -/* Pick out the correct pixels for the interlace pass. - * The basic idea here is to go through the row with a source - * pointer and a destination pointer (sp and dp), and copy the - * correct pixels for the pass. As the row gets compacted, - * sp will always be >= dp, so we should never overwrite anything. - * See the default: case for the easiest code to understand. - */ -void /* PRIVATE */ -png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) -{ - /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ - - /* Start of interlace block */ - static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; - - /* Offset to next interlace block */ - static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; - - png_debug(1, "in png_do_write_interlace"); - - /* We don't have to do anything on the last pass (6) */ - if (pass < 6) - { - /* Each pixel depth is handled separately */ - switch (row_info->pixel_depth) - { - case 1: - { - png_bytep sp; - png_bytep dp; - int shift; - int d; - int value; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - dp = row; - d = 0; - shift = 7; - - for (i = png_pass_start[pass]; i < row_width; - i += png_pass_inc[pass]) - { - sp = row + (png_size_t)(i >> 3); - value = (int)(*sp >> (7 - (int)(i & 0x07))) & 0x01; - d |= (value << shift); - - if (shift == 0) - { - shift = 7; - *dp++ = (png_byte)d; - d = 0; - } - - else - shift--; - - } - if (shift != 7) - *dp = (png_byte)d; - - break; - } - - case 2: - { - png_bytep sp; - png_bytep dp; - int shift; - int d; - int value; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - dp = row; - shift = 6; - d = 0; - - for (i = png_pass_start[pass]; i < row_width; - i += png_pass_inc[pass]) - { - sp = row + (png_size_t)(i >> 2); - value = (*sp >> ((3 - (int)(i & 0x03)) << 1)) & 0x03; - d |= (value << shift); - - if (shift == 0) - { - shift = 6; - *dp++ = (png_byte)d; - d = 0; - } - - else - shift -= 2; - } - if (shift != 6) - *dp = (png_byte)d; - - break; - } - - case 4: - { - png_bytep sp; - png_bytep dp; - int shift; - int d; - int value; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - - dp = row; - shift = 4; - d = 0; - for (i = png_pass_start[pass]; i < row_width; - i += png_pass_inc[pass]) - { - sp = row + (png_size_t)(i >> 1); - value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f; - d |= (value << shift); - - if (shift == 0) - { - shift = 4; - *dp++ = (png_byte)d; - d = 0; - } - - else - shift -= 4; - } - if (shift != 4) - *dp = (png_byte)d; - - break; - } - - default: - { - png_bytep sp; - png_bytep dp; - png_uint_32 i; - png_uint_32 row_width = row_info->width; - png_size_t pixel_bytes; - - /* Start at the beginning */ - dp = row; - - /* Find out how many bytes each pixel takes up */ - pixel_bytes = (row_info->pixel_depth >> 3); - - /* Loop through the row, only looking at the pixels that matter */ - for (i = png_pass_start[pass]; i < row_width; - i += png_pass_inc[pass]) - { - /* Find out where the original pixel is */ - sp = row + (png_size_t)i * pixel_bytes; - - /* Move the pixel */ - if (dp != sp) - memcpy(dp, sp, pixel_bytes); - - /* Next pixel */ - dp += pixel_bytes; - } - break; - } - } - /* Set new row width */ - row_info->width = (row_info->width + - png_pass_inc[pass] - 1 - - png_pass_start[pass]) / - png_pass_inc[pass]; - - row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth, - row_info->width); - } -} -#endif - -/* This filters the row, chooses which filter to use, if it has not already - * been specified by the application, and then writes the row out with the - * chosen filter. - */ -static void -png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row, - png_size_t row_bytes); - -#define PNG_MAXSUM (((png_uint_32)(-1)) >> 1) -#define PNG_HISHIFT 10 -#define PNG_LOMASK ((png_uint_32)0xffffL) -#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT)) -void /* PRIVATE */ -png_write_find_filter(png_structrp png_ptr, png_row_infop row_info) -{ - png_bytep best_row; -#ifdef PNG_WRITE_FILTER_SUPPORTED - png_bytep prev_row, row_buf; - png_uint_32 mins, bpp; - png_byte filter_to_do = png_ptr->do_filter; - png_size_t row_bytes = row_info->rowbytes; -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - int num_p_filters = png_ptr->num_prev_filters; -#endif - - png_debug(1, "in png_write_find_filter"); - -#ifndef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->row_number == 0 && filter_to_do == PNG_ALL_FILTERS) - { - /* These will never be selected so we need not test them. */ - filter_to_do &= ~(PNG_FILTER_UP | PNG_FILTER_PAETH); - } -#endif - - /* Find out how many bytes offset each pixel is */ - bpp = (row_info->pixel_depth + 7) >> 3; - - prev_row = png_ptr->prev_row; -#endif - best_row = png_ptr->row_buf; -#ifdef PNG_WRITE_FILTER_SUPPORTED - row_buf = best_row; - mins = PNG_MAXSUM; - - /* The prediction method we use is to find which method provides the - * smallest value when summing the absolute values of the distances - * from zero, using anything >= 128 as negative numbers. This is known - * as the "minimum sum of absolute differences" heuristic. Other - * heuristics are the "weighted minimum sum of absolute differences" - * (experimental and can in theory improve compression), and the "zlib - * predictive" method (not implemented yet), which does test compressions - * of lines using different filter methods, and then chooses the - * (series of) filter(s) that give minimum compressed data size (VERY - * computationally expensive). - * - * GRR 980525: consider also - * - * (1) minimum sum of absolute differences from running average (i.e., - * keep running sum of non-absolute differences & count of bytes) - * [track dispersion, too? restart average if dispersion too large?] - * - * (1b) minimum sum of absolute differences from sliding average, probably - * with window size <= deflate window (usually 32K) - * - * (2) minimum sum of squared differences from zero or running average - * (i.e., ~ root-mean-square approach) - */ - - - /* We don't need to test the 'no filter' case if this is the only filter - * that has been chosen, as it doesn't actually do anything to the data. - */ - if ((filter_to_do & PNG_FILTER_NONE) && filter_to_do != PNG_FILTER_NONE) - { - png_bytep rp; - png_uint_32 sum = 0; - png_size_t i; - int v; - - for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) - { - v = *rp; - sum += (v < 128) ? v : 256 - v; - } - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - png_uint_32 sumhi, sumlo; - int j; - sumlo = sum & PNG_LOMASK; - sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */ - - /* Reduce the sum if we match any of the previous rows */ - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) - { - sumlo = (sumlo * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - sumhi = (sumhi * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - /* Factor in the cost of this filter (this is here for completeness, - * but it makes no sense to have a "cost" for the NONE filter, as - * it has the minimum possible computational cost - none). - */ - sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> - PNG_COST_SHIFT; - - sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> - PNG_COST_SHIFT; - - if (sumhi > PNG_HIMASK) - sum = PNG_MAXSUM; - - else - sum = (sumhi << PNG_HISHIFT) + sumlo; - } -#endif - mins = sum; - } - - /* Sub filter */ - if (filter_to_do == PNG_FILTER_SUB) - /* It's the only filter so no testing is needed */ - { - png_bytep rp, lp, dp; - png_size_t i; - - for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp; - i++, rp++, dp++) - { - *dp = *rp; - } - - for (lp = row_buf + 1; i < row_bytes; - i++, rp++, lp++, dp++) - { - *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); - } - - best_row = png_ptr->sub_row; - } - - else if (filter_to_do & PNG_FILTER_SUB) - { - png_bytep rp, dp, lp; - png_uint_32 sum = 0, lmins = mins; - png_size_t i; - int v; - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - /* We temporarily increase the "minimum sum" by the factor we - * would reduce the sum of this filter, so that we can do the - * early exit comparison without scaling the sum each time. - */ - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 lmhi, lmlo; - lmlo = lmins & PNG_LOMASK; - lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) - { - lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> - PNG_COST_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> - PNG_COST_SHIFT; - - if (lmhi > PNG_HIMASK) - lmins = PNG_MAXSUM; - - else - lmins = (lmhi << PNG_HISHIFT) + lmlo; - } -#endif - - for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp; - i++, rp++, dp++) - { - v = *dp = *rp; - - sum += (v < 128) ? v : 256 - v; - } - - for (lp = row_buf + 1; i < row_bytes; - i++, rp++, lp++, dp++) - { - v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); - - sum += (v < 128) ? v : 256 - v; - - if (sum > lmins) /* We are already worse, don't continue. */ - break; - } - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 sumhi, sumlo; - sumlo = sum & PNG_LOMASK; - sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_SUB) - { - sumlo = (sumlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - sumhi = (sumhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> - PNG_COST_SHIFT; - - sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> - PNG_COST_SHIFT; - - if (sumhi > PNG_HIMASK) - sum = PNG_MAXSUM; - - else - sum = (sumhi << PNG_HISHIFT) + sumlo; - } -#endif - - if (sum < mins) - { - mins = sum; - best_row = png_ptr->sub_row; - } - } - - /* Up filter */ - if (filter_to_do == PNG_FILTER_UP) - { - png_bytep rp, dp, pp; - png_size_t i; - - for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, - pp = prev_row + 1; i < row_bytes; - i++, rp++, pp++, dp++) - { - *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); - } - - best_row = png_ptr->up_row; - } - - else if (filter_to_do & PNG_FILTER_UP) - { - png_bytep rp, dp, pp; - png_uint_32 sum = 0, lmins = mins; - png_size_t i; - int v; - - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 lmhi, lmlo; - lmlo = lmins & PNG_LOMASK; - lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) - { - lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> - PNG_COST_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> - PNG_COST_SHIFT; - - if (lmhi > PNG_HIMASK) - lmins = PNG_MAXSUM; - - else - lmins = (lmhi << PNG_HISHIFT) + lmlo; - } -#endif - - for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, - pp = prev_row + 1; i < row_bytes; i++) - { - v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); - - sum += (v < 128) ? v : 256 - v; - - if (sum > lmins) /* We are already worse, don't continue. */ - break; - } - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 sumhi, sumlo; - sumlo = sum & PNG_LOMASK; - sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_UP) - { - sumlo = (sumlo * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - sumhi = (sumhi * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> - PNG_COST_SHIFT; - - sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> - PNG_COST_SHIFT; - - if (sumhi > PNG_HIMASK) - sum = PNG_MAXSUM; - - else - sum = (sumhi << PNG_HISHIFT) + sumlo; - } -#endif - - if (sum < mins) - { - mins = sum; - best_row = png_ptr->up_row; - } - } - - /* Avg filter */ - if (filter_to_do == PNG_FILTER_AVG) - { - png_bytep rp, dp, pp, lp; - png_uint_32 i; - - for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, - pp = prev_row + 1; i < bpp; i++) - { - *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); - } - - for (lp = row_buf + 1; i < row_bytes; i++) - { - *dp++ = (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) - & 0xff); - } - best_row = png_ptr->avg_row; - } - - else if (filter_to_do & PNG_FILTER_AVG) - { - png_bytep rp, dp, pp, lp; - png_uint_32 sum = 0, lmins = mins; - png_size_t i; - int v; - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 lmhi, lmlo; - lmlo = lmins & PNG_LOMASK; - lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_AVG) - { - lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> - PNG_COST_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> - PNG_COST_SHIFT; - - if (lmhi > PNG_HIMASK) - lmins = PNG_MAXSUM; - - else - lmins = (lmhi << PNG_HISHIFT) + lmlo; - } -#endif - - for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, - pp = prev_row + 1; i < bpp; i++) - { - v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); - - sum += (v < 128) ? v : 256 - v; - } - - for (lp = row_buf + 1; i < row_bytes; i++) - { - v = *dp++ = - (png_byte)(((int)*rp++ - (((int)*pp++ + (int)*lp++) / 2)) & 0xff); - - sum += (v < 128) ? v : 256 - v; - - if (sum > lmins) /* We are already worse, don't continue. */ - break; - } - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 sumhi, sumlo; - sumlo = sum & PNG_LOMASK; - sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_NONE) - { - sumlo = (sumlo * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - sumhi = (sumhi * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> - PNG_COST_SHIFT; - - sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> - PNG_COST_SHIFT; - - if (sumhi > PNG_HIMASK) - sum = PNG_MAXSUM; - - else - sum = (sumhi << PNG_HISHIFT) + sumlo; - } -#endif - - if (sum < mins) - { - mins = sum; - best_row = png_ptr->avg_row; - } - } - - /* Paeth filter */ - if (filter_to_do == PNG_FILTER_PAETH) - { - png_bytep rp, dp, pp, cp, lp; - png_size_t i; - - for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, - pp = prev_row + 1; i < bpp; i++) - { - *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); - } - - for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++) - { - int a, b, c, pa, pb, pc, p; - - b = *pp++; - c = *cp++; - a = *lp++; - - p = b - c; - pc = a - c; - -#ifdef PNG_USE_ABS - pa = abs(p); - pb = abs(pc); - pc = abs(p + pc); -#else - pa = p < 0 ? -p : p; - pb = pc < 0 ? -pc : pc; - pc = (p + pc) < 0 ? -(p + pc) : p + pc; -#endif - - p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; - - *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); - } - best_row = png_ptr->paeth_row; - } - - else if (filter_to_do & PNG_FILTER_PAETH) - { - png_bytep rp, dp, pp, cp, lp; - png_uint_32 sum = 0, lmins = mins; - png_size_t i; - int v; - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 lmhi, lmlo; - lmlo = lmins & PNG_LOMASK; - lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) - { - lmlo = (lmlo * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> - PNG_COST_SHIFT; - - lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> - PNG_COST_SHIFT; - - if (lmhi > PNG_HIMASK) - lmins = PNG_MAXSUM; - - else - lmins = (lmhi << PNG_HISHIFT) + lmlo; - } -#endif - - for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, - pp = prev_row + 1; i < bpp; i++) - { - v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); - - sum += (v < 128) ? v : 256 - v; - } - - for (lp = row_buf + 1, cp = prev_row + 1; i < row_bytes; i++) - { - int a, b, c, pa, pb, pc, p; - - b = *pp++; - c = *cp++; - a = *lp++; - -#ifndef PNG_SLOW_PAETH - p = b - c; - pc = a - c; -#ifdef PNG_USE_ABS - pa = abs(p); - pb = abs(pc); - pc = abs(p + pc); -#else - pa = p < 0 ? -p : p; - pb = pc < 0 ? -pc : pc; - pc = (p + pc) < 0 ? -(p + pc) : p + pc; -#endif - p = (pa <= pb && pa <=pc) ? a : (pb <= pc) ? b : c; -#else /* PNG_SLOW_PAETH */ - p = a + b - c; - pa = abs(p - a); - pb = abs(p - b); - pc = abs(p - c); - - if (pa <= pb && pa <= pc) - p = a; - - else if (pb <= pc) - p = b; - - else - p = c; -#endif /* PNG_SLOW_PAETH */ - - v = *dp++ = (png_byte)(((int)*rp++ - p) & 0xff); - - sum += (v < 128) ? v : 256 - v; - - if (sum > lmins) /* We are already worse, don't continue. */ - break; - } - -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) - { - int j; - png_uint_32 sumhi, sumlo; - sumlo = sum & PNG_LOMASK; - sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; - - for (j = 0; j < num_p_filters; j++) - { - if (png_ptr->prev_filters[j] == PNG_FILTER_VALUE_PAETH) - { - sumlo = (sumlo * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - - sumhi = (sumhi * png_ptr->filter_weights[j]) >> - PNG_WEIGHT_SHIFT; - } - } - - sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> - PNG_COST_SHIFT; - - sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> - PNG_COST_SHIFT; - - if (sumhi > PNG_HIMASK) - sum = PNG_MAXSUM; - - else - sum = (sumhi << PNG_HISHIFT) + sumlo; - } -#endif - - if (sum < mins) - { - best_row = png_ptr->paeth_row; - } - } -#endif /* PNG_WRITE_FILTER_SUPPORTED */ - - /* Do the actual writing of the filtered row data from the chosen filter. */ - png_write_filtered_row(png_ptr, best_row, row_info->rowbytes+1); - -#ifdef PNG_WRITE_FILTER_SUPPORTED -#ifdef PNG_WRITE_WEIGHTED_FILTER_SUPPORTED - /* Save the type of filter we picked this time for future calculations */ - if (png_ptr->num_prev_filters > 0) - { - int j; - - for (j = 1; j < num_p_filters; j++) - { - png_ptr->prev_filters[j] = png_ptr->prev_filters[j - 1]; - } - - png_ptr->prev_filters[j] = best_row[0]; - } -#endif -#endif /* PNG_WRITE_FILTER_SUPPORTED */ -} - - -/* Do the actual writing of a previously filtered row. */ -static void -png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row, - png_size_t full_row_length/*includes filter byte*/) -{ - png_debug(1, "in png_write_filtered_row"); - - png_debug1(2, "filter = %d", filtered_row[0]); - - png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH); - - /* Swap the current and previous rows */ - if (png_ptr->prev_row != NULL) - { - png_bytep tptr; - - tptr = png_ptr->prev_row; - png_ptr->prev_row = png_ptr->row_buf; - png_ptr->row_buf = tptr; - } - - /* Finish row - updates counters and flushes zlib if last row */ - png_write_finish_row(png_ptr); - -#ifdef PNG_WRITE_FLUSH_SUPPORTED - png_ptr->flush_rows++; - - if (png_ptr->flush_dist > 0 && - png_ptr->flush_rows >= png_ptr->flush_dist) - { - png_write_flush(png_ptr); - } -#endif -} -#endif /* PNG_WRITE_SUPPORTED */ |