/* pngwutil.c - utilities to write a PNG file | |
* | |
* Last changed in libpng 1.5.4 [July 7, 2011] | |
* Copyright (c) 1998-2011 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); | |
} | |
#ifdef PNG_SAVE_INT_32_SUPPORTED | |
/* The png_save_int_32 function assumes integers are stored in two's | |
* complement format. If this isn't the case, then this routine needs to | |
* be modified to write data in two's complement format. Note that, | |
* the following works correctly even if png_int_32 has more than 32 bits | |
* (compare the more complex code required on read for sign extention.) | |
*/ | |
void PNGAPI | |
png_save_int_32(png_bytep buf, png_int_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); | |
} | |
#endif | |
/* 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_structp 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 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. | |
*/ | |
void PNGAPI | |
png_write_chunk(png_structp png_ptr, png_const_bytep chunk_name, | |
png_const_bytep data, png_size_t length) | |
{ | |
if (png_ptr == NULL) | |
return; | |
png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length); | |
png_write_chunk_data(png_ptr, data, (png_size_t)length); | |
png_write_chunk_end(png_ptr); | |
} | |
/* 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(). | |
*/ | |
void PNGAPI | |
png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_name, | |
png_uint_32 length) | |
{ | |
png_byte buf[8]; | |
png_debug2(0, "Writing %s chunk, length = %lu", chunk_name, | |
(unsigned long)length); | |
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_memcpy(buf + 4, chunk_name, 4); | |
png_write_data(png_ptr, buf, (png_size_t)8); | |
/* Put the chunk name into png_ptr->chunk_name */ | |
png_memcpy(png_ptr->chunk_name, chunk_name, 4); | |
/* Reset the crc and run it over the chunk name */ | |
png_reset_crc(png_ptr); | |
png_calculate_crc(png_ptr, chunk_name, 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 | |
} | |
/* Write the data of a PNG chunk started with png_write_chunk_start(). | |
* 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_start(). | |
*/ | |
void PNGAPI | |
png_write_chunk_data(png_structp 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_start(). */ | |
void PNGAPI | |
png_write_chunk_end(png_structp 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); | |
} | |
/* Initialize the compressor for the appropriate type of compression. */ | |
static void | |
png_zlib_claim(png_structp png_ptr, png_uint_32 state) | |
{ | |
if (!(png_ptr->zlib_state & PNG_ZLIB_IN_USE)) | |
{ | |
/* If already initialized for 'state' do not re-init. */ | |
if (png_ptr->zlib_state != state) | |
{ | |
int ret = Z_OK; | |
png_const_charp who = "-"; | |
/* If actually initialized for another state do a deflateEnd. */ | |
if (png_ptr->zlib_state != PNG_ZLIB_UNINITIALIZED) | |
{ | |
ret = deflateEnd(&png_ptr->zstream); | |
who = "end"; | |
png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED; | |
} | |
/* zlib itself detects an incomplete state on deflateEnd */ | |
if (ret == Z_OK) switch (state) | |
{ | |
# ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED | |
case PNG_ZLIB_FOR_TEXT: | |
ret = deflateInit2(&png_ptr->zstream, | |
png_ptr->zlib_text_level, png_ptr->zlib_text_method, | |
png_ptr->zlib_text_window_bits, | |
png_ptr->zlib_text_mem_level, png_ptr->zlib_text_strategy); | |
who = "text"; | |
break; | |
# endif | |
case PNG_ZLIB_FOR_IDAT: | |
ret = deflateInit2(&png_ptr->zstream, png_ptr->zlib_level, | |
png_ptr->zlib_method, png_ptr->zlib_window_bits, | |
png_ptr->zlib_mem_level, png_ptr->zlib_strategy); | |
who = "IDAT"; | |
break; | |
default: | |
png_error(png_ptr, "invalid zlib state"); | |
} | |
if (ret == Z_OK) | |
png_ptr->zlib_state = state; | |
else /* an error in deflateEnd or deflateInit2 */ | |
{ | |
size_t pos = 0; | |
char msg[64]; | |
pos = png_safecat(msg, sizeof msg, pos, | |
"zlib failed to initialize compressor ("); | |
pos = png_safecat(msg, sizeof msg, pos, who); | |
switch (ret) | |
{ | |
case Z_VERSION_ERROR: | |
pos = png_safecat(msg, sizeof msg, pos, ") version error"); | |
break; | |
case Z_STREAM_ERROR: | |
pos = png_safecat(msg, sizeof msg, pos, ") stream error"); | |
break; | |
case Z_MEM_ERROR: | |
pos = png_safecat(msg, sizeof msg, pos, ") memory error"); | |
break; | |
default: | |
pos = png_safecat(msg, sizeof msg, pos, ") unknown error"); | |
break; | |
} | |
png_error(png_ptr, msg); | |
} | |
} | |
/* Here on success, claim the zstream: */ | |
png_ptr->zlib_state |= PNG_ZLIB_IN_USE; | |
} | |
else | |
png_error(png_ptr, "zstream already in use (internal error)"); | |
} | |
/* The opposite: release the stream. It is also reset, this API will warn on | |
* error but will not fail. | |
*/ | |
static void | |
png_zlib_release(png_structp png_ptr) | |
{ | |
if (png_ptr->zlib_state & PNG_ZLIB_IN_USE) | |
{ | |
int ret = deflateReset(&png_ptr->zstream); | |
png_ptr->zlib_state &= ~PNG_ZLIB_IN_USE; | |
if (ret != Z_OK) | |
{ | |
png_const_charp err; | |
PNG_WARNING_PARAMETERS(p) | |
switch (ret) | |
{ | |
case Z_VERSION_ERROR: | |
err = "version"; | |
break; | |
case Z_STREAM_ERROR: | |
err = "stream"; | |
break; | |
case Z_MEM_ERROR: | |
err = "memory"; | |
break; | |
default: | |
err = "unknown"; | |
break; | |
} | |
png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, ret); | |
png_warning_parameter(p, 2, err); | |
if (png_ptr->zstream.msg) | |
err = png_ptr->zstream.msg; | |
else | |
err = "[no zlib message]"; | |
png_warning_parameter(p, 3, err); | |
png_formatted_warning(png_ptr, p, | |
"zlib failed to reset compressor: @1(@2): @3"); | |
} | |
} | |
else | |
png_warning(png_ptr, "zstream not in use (internal error)"); | |
} | |
#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 in order to make the whole mess thread-safe. | |
*/ | |
typedef struct | |
{ | |
png_const_bytep input; /* The uncompressed input data */ | |
png_size_t input_len; /* Its length */ | |
int num_output_ptr; /* Number of output pointers used */ | |
int max_output_ptr; /* Size of output_ptr */ | |
png_bytep *output_ptr; /* Array of pointers to output */ | |
} compression_state; | |
/* Compress given text into storage in the png_ptr structure */ | |
static int /* PRIVATE */ | |
png_text_compress(png_structp png_ptr, | |
png_const_charp text, png_size_t text_len, int compression, | |
compression_state *comp) | |
{ | |
int ret; | |
comp->num_output_ptr = 0; | |
comp->max_output_ptr = 0; | |
comp->output_ptr = NULL; | |
comp->input = NULL; | |
comp->input_len = text_len; | |
/* We may just want to pass the text right through */ | |
if (compression == PNG_TEXT_COMPRESSION_NONE) | |
{ | |
comp->input = (png_const_bytep)text; | |
return((int)text_len); | |
} | |
if (compression >= PNG_TEXT_COMPRESSION_LAST) | |
{ | |
PNG_WARNING_PARAMETERS(p) | |
png_warning_parameter_signed(p, 1, PNG_NUMBER_FORMAT_d, | |
compression); | |
png_formatted_warning(png_ptr, p, "Unknown compression type @1"); | |
} | |
/* We can't write the chunk until we find out how much data we have, | |
* which means we need to run the compressor first and save the | |
* output. This shouldn't be a problem, as the vast majority of | |
* comments should be reasonable, but we will set up an array of | |
* malloc'd pointers to be sure. | |
* | |
* If we knew the application was well behaved, we could simplify this | |
* greatly by assuming we can always malloc an output buffer large | |
* enough to hold the compressed text ((1001 * text_len / 1000) + 12) | |
* and malloc this directly. The only time this would be a bad idea is | |
* if we can't malloc more than 64K and we have 64K of random input | |
* data, or if the input string is incredibly large (although this | |
* wouldn't cause a failure, just a slowdown due to swapping). | |
*/ | |
png_zlib_claim(png_ptr, PNG_ZLIB_FOR_TEXT); | |
/* Set up the compression buffers */ | |
/* TODO: the following cast hides a potential overflow problem. */ | |
png_ptr->zstream.avail_in = (uInt)text_len; | |
/* NOTE: assume zlib doesn't overwrite the input */ | |
png_ptr->zstream.next_in = (Bytef *)text; | |
png_ptr->zstream.avail_out = png_ptr->zbuf_size; | |
png_ptr->zstream.next_out = png_ptr->zbuf; | |
/* This is the same compression loop as in png_write_row() */ | |
do | |
{ | |
/* Compress the data */ | |
ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); | |
if (ret != Z_OK) | |
{ | |
/* Error */ | |
if (png_ptr->zstream.msg != NULL) | |
png_error(png_ptr, png_ptr->zstream.msg); | |
else | |
png_error(png_ptr, "zlib error"); | |
} | |
/* Check to see if we need more room */ | |
if (!(png_ptr->zstream.avail_out)) | |
{ | |
/* Make sure the output array has room */ | |
if (comp->num_output_ptr >= comp->max_output_ptr) | |
{ | |
int old_max; | |
old_max = comp->max_output_ptr; | |
comp->max_output_ptr = comp->num_output_ptr + 4; | |
if (comp->output_ptr != NULL) | |
{ | |
png_bytepp old_ptr; | |
old_ptr = comp->output_ptr; | |
comp->output_ptr = (png_bytepp)png_malloc(png_ptr, | |
(png_alloc_size_t) | |
(comp->max_output_ptr * png_sizeof(png_charpp))); | |
png_memcpy(comp->output_ptr, old_ptr, old_max | |
* png_sizeof(png_charp)); | |
png_free(png_ptr, old_ptr); | |
} | |
else | |
comp->output_ptr = (png_bytepp)png_malloc(png_ptr, | |
(png_alloc_size_t) | |
(comp->max_output_ptr * png_sizeof(png_charp))); | |
} | |
/* Save the data */ | |
comp->output_ptr[comp->num_output_ptr] = | |
(png_bytep)png_malloc(png_ptr, | |
(png_alloc_size_t)png_ptr->zbuf_size); | |
png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, | |
png_ptr->zbuf_size); | |
comp->num_output_ptr++; | |
/* and reset the buffer */ | |
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; | |
png_ptr->zstream.next_out = png_ptr->zbuf; | |
} | |
/* Continue until we don't have any more to compress */ | |
} while (png_ptr->zstream.avail_in); | |
/* Finish the compression */ | |
do | |
{ | |
/* Tell zlib we are finished */ | |
ret = deflate(&png_ptr->zstream, Z_FINISH); | |
if (ret == Z_OK) | |
{ | |
/* Check to see if we need more room */ | |
if (!(png_ptr->zstream.avail_out)) | |
{ | |
/* Check to make sure our output array has room */ | |
if (comp->num_output_ptr >= comp->max_output_ptr) | |
{ | |
int old_max; | |
old_max = comp->max_output_ptr; | |
comp->max_output_ptr = comp->num_output_ptr + 4; | |
if (comp->output_ptr != NULL) | |
{ | |
png_bytepp old_ptr; | |
old_ptr = comp->output_ptr; | |
/* This could be optimized to realloc() */ | |
comp->output_ptr = (png_bytepp)png_malloc(png_ptr, | |
(png_alloc_size_t)(comp->max_output_ptr * | |
png_sizeof(png_charp))); | |
png_memcpy(comp->output_ptr, old_ptr, | |
old_max * png_sizeof(png_charp)); | |
png_free(png_ptr, old_ptr); | |
} | |
else | |
comp->output_ptr = (png_bytepp)png_malloc(png_ptr, | |
(png_alloc_size_t)(comp->max_output_ptr * | |
png_sizeof(png_charp))); | |
} | |
/* Save the data */ | |
comp->output_ptr[comp->num_output_ptr] = | |
(png_bytep)png_malloc(png_ptr, | |
(png_alloc_size_t)png_ptr->zbuf_size); | |
png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, | |
png_ptr->zbuf_size); | |
comp->num_output_ptr++; | |
/* and reset the buffer pointers */ | |
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; | |
png_ptr->zstream.next_out = png_ptr->zbuf; | |
} | |
} | |
else if (ret != Z_STREAM_END) | |
{ | |
/* We got an error */ | |
if (png_ptr->zstream.msg != NULL) | |
png_error(png_ptr, png_ptr->zstream.msg); | |
else | |
png_error(png_ptr, "zlib error"); | |
} | |
} while (ret != Z_STREAM_END); | |
/* Text length is number of buffers plus last buffer */ | |
text_len = png_ptr->zbuf_size * comp->num_output_ptr; | |
if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) | |
text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out; | |
return((int)text_len); | |
} | |
/* Ship the compressed text out via chunk writes */ | |
static void /* PRIVATE */ | |
png_write_compressed_data_out(png_structp png_ptr, compression_state *comp) | |
{ | |
int i; | |
/* Handle the no-compression case */ | |
if (comp->input) | |
{ | |
png_write_chunk_data(png_ptr, comp->input, comp->input_len); | |
return; | |
} | |
#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED | |
if (comp->input_len >= 2 && comp->input_len < 16384) | |
{ | |
unsigned int z_cmf; /* zlib compression method and flags */ | |
/* Optimize the CMF field in the zlib stream. This hack of the zlib | |
* stream is compliant to the stream specification. | |
*/ | |
if (comp->num_output_ptr) | |
z_cmf = comp->output_ptr[0][0]; | |
else | |
z_cmf = png_ptr->zbuf[0]; | |
if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) | |
{ | |
unsigned int z_cinfo; | |
unsigned int half_z_window_size; | |
png_size_t uncompressed_text_size = comp->input_len; | |
z_cinfo = z_cmf >> 4; | |
half_z_window_size = 1 << (z_cinfo + 7); | |
while (uncompressed_text_size <= half_z_window_size && | |
half_z_window_size >= 256) | |
{ | |
z_cinfo--; | |
half_z_window_size >>= 1; | |
} | |
z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); | |
if (comp->num_output_ptr) | |
{ | |
if (comp->output_ptr[0][0] != z_cmf) | |
{ | |
int tmp; | |
comp->output_ptr[0][0] = (png_byte)z_cmf; | |
tmp = comp->output_ptr[0][1] & 0xe0; | |
tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; | |
comp->output_ptr[0][1] = (png_byte)tmp; | |
} | |
} | |
else | |
{ | |
int tmp; | |
png_ptr->zbuf[0] = (png_byte)z_cmf; | |
tmp = png_ptr->zbuf[1] & 0xe0; | |
tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; | |
png_ptr->zbuf[1] = (png_byte)tmp; | |
} | |
} | |
else | |
png_error(png_ptr, | |
"Invalid zlib compression method or flags in non-IDAT chunk"); | |
} | |
#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */ | |
/* Write saved output buffers, if any */ | |
for (i = 0; i < comp->num_output_ptr; i++) | |
{ | |
png_write_chunk_data(png_ptr, comp->output_ptr[i], | |
(png_size_t)png_ptr->zbuf_size); | |
png_free(png_ptr, comp->output_ptr[i]); | |
} | |
if (comp->max_output_ptr != 0) | |
png_free(png_ptr, comp->output_ptr); | |
/* Write anything left in zbuf */ | |
if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size) | |
png_write_chunk_data(png_ptr, png_ptr->zbuf, | |
(png_size_t)(png_ptr->zbuf_size - png_ptr->zstream.avail_out)); | |
/* Reset zlib for another zTXt/iTXt or image data */ | |
png_zlib_release(png_ptr); | |
} | |
#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */ | |
/* 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_structp 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_IHDR; | |
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_chunk(png_ptr, png_IHDR, buf, (png_size_t)13); | |
/* Initialize zlib with PNG info */ | |
png_ptr->zstream.zalloc = png_zalloc; | |
png_ptr->zstream.zfree = png_zfree; | |
png_ptr->zstream.opaque = (voidpf)png_ptr; | |
if (!(png_ptr->do_filter)) | |
{ | |
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; | |
} | |
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY)) | |
{ | |
if (png_ptr->do_filter != PNG_FILTER_NONE) | |
png_ptr->zlib_strategy = Z_FILTERED; | |
else | |
png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY; | |
} | |
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL)) | |
png_ptr->zlib_level = Z_DEFAULT_COMPRESSION; | |
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL)) | |
png_ptr->zlib_mem_level = 8; | |
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS)) | |
png_ptr->zlib_window_bits = 15; | |
if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD)) | |
png_ptr->zlib_method = 8; | |
#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED | |
#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED | |
if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_STRATEGY)) | |
png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY; | |
if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_LEVEL)) | |
png_ptr->zlib_text_level = png_ptr->zlib_level; | |
if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_MEM_LEVEL)) | |
png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level; | |
if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_WINDOW_BITS)) | |
png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits; | |
if (!(png_ptr->flags & PNG_FLAG_ZTXT_CUSTOM_METHOD)) | |
png_ptr->zlib_text_method = png_ptr->zlib_method; | |
#else | |
png_ptr->zlib_text_strategy = Z_DEFAULT_STRATEGY; | |
png_ptr->zlib_text_level = png_ptr->zlib_level; | |
png_ptr->zlib_text_mem_level = png_ptr->zlib_mem_level; | |
png_ptr->zlib_text_window_bits = png_ptr->zlib_window_bits; | |
png_ptr->zlib_text_method = png_ptr->zlib_method; | |
#endif /* PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED */ | |
#endif /* PNG_WRITE_COMPRESSED_TEXT_SUPPORTED */ | |
/* Record that the compressor has not yet been initialized. */ | |
png_ptr->zlib_state = PNG_ZLIB_UNINITIALIZED; | |
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_structp png_ptr, png_const_colorp palette, | |
png_uint_32 num_pal) | |
{ | |
PNG_PLTE; | |
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_start(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; | |
} | |
/* Write an IDAT chunk */ | |
void /* PRIVATE */ | |
png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length) | |
{ | |
PNG_IDAT; | |
png_debug(1, "in png_write_IDAT"); | |
#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED | |
if (!(png_ptr->mode & PNG_HAVE_IDAT) && | |
png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) | |
{ | |
/* Optimize the CMF field in the zlib stream. This hack of the zlib | |
* stream is compliant to the stream specification. | |
*/ | |
unsigned int z_cmf = data[0]; /* zlib compression method and flags */ | |
if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) | |
{ | |
/* Avoid memory underflows and multiplication overflows. | |
* | |
* The conditions below are practically always satisfied; | |
* however, they still must be checked. | |
*/ | |
if (length >= 2 && | |
png_ptr->height < 16384 && png_ptr->width < 16384) | |
{ | |
/* Compute the maximum possible length of the datastream */ | |
/* Number of pixels, plus for each row a filter byte | |
* and possibly a padding byte, so increase the maximum | |
* size to account for these. | |
*/ | |
unsigned int z_cinfo; | |
unsigned int half_z_window_size; | |
png_uint_32 uncompressed_idat_size = png_ptr->height * | |
((png_ptr->width * | |
png_ptr->channels * png_ptr->bit_depth + 15) >> 3); | |
/* If it's interlaced, each block of 8 rows is sent as up to | |
* 14 rows, i.e., 6 additional rows, each with a filter byte | |
* and possibly a padding byte | |
*/ | |
if (png_ptr->interlaced) | |
uncompressed_idat_size += ((png_ptr->height + 7)/8) * | |
(png_ptr->bit_depth < 8 ? 12 : 6); | |
z_cinfo = z_cmf >> 4; | |
half_z_window_size = 1 << (z_cinfo + 7); | |
while (uncompressed_idat_size <= half_z_window_size && | |
half_z_window_size >= 256) | |
{ | |
z_cinfo--; | |
half_z_window_size >>= 1; | |
} | |
z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); | |
if (data[0] != z_cmf) | |
{ | |
int tmp; | |
data[0] = (png_byte)z_cmf; | |
tmp = data[1] & 0xe0; | |
tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; | |
data[1] = (png_byte)tmp; | |
} | |
} | |
} | |
else | |
png_error(png_ptr, | |
"Invalid zlib compression method or flags in IDAT"); | |
} | |
#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */ | |
png_write_chunk(png_ptr, png_IDAT, data, length); | |
png_ptr->mode |= PNG_HAVE_IDAT; | |
/* Prior to 1.5.4 this code was replicated in every caller (except at the | |
* end, where it isn't technically necessary). Since this function has | |
* flushed the data we can safely reset the zlib output buffer here. | |
*/ | |
png_ptr->zstream.next_out = png_ptr->zbuf; | |
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; | |
} | |
/* Write an IEND chunk */ | |
void /* PRIVATE */ | |
png_write_IEND(png_structp png_ptr) | |
{ | |
PNG_IEND; | |
png_debug(1, "in png_write_IEND"); | |
png_write_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_structp png_ptr, png_fixed_point file_gamma) | |
{ | |
PNG_gAMA; | |
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_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_structp png_ptr, int srgb_intent) | |
{ | |
PNG_sRGB; | |
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_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_structp png_ptr, png_const_charp name, int compression_type, | |
png_const_charp profile, int profile_len) | |
{ | |
PNG_iCCP; | |
png_size_t name_len; | |
png_charp new_name; | |
compression_state comp; | |
int embedded_profile_len = 0; | |
png_debug(1, "in png_write_iCCP"); | |
comp.num_output_ptr = 0; | |
comp.max_output_ptr = 0; | |
comp.output_ptr = NULL; | |
comp.input = NULL; | |
comp.input_len = 0; | |
if ((name_len = png_check_keyword(png_ptr, name, &new_name)) == 0) | |
return; | |
if (compression_type != PNG_COMPRESSION_TYPE_BASE) | |
png_warning(png_ptr, "Unknown compression type in iCCP chunk"); | |
if (profile == NULL) | |
profile_len = 0; | |
if (profile_len > 3) | |
embedded_profile_len = | |
((*( (png_const_bytep)profile ))<<24) | | |
((*( (png_const_bytep)profile + 1))<<16) | | |
((*( (png_const_bytep)profile + 2))<< 8) | | |
((*( (png_const_bytep)profile + 3)) ); | |
if (embedded_profile_len < 0) | |
{ | |
png_warning(png_ptr, | |
"Embedded profile length in iCCP chunk is negative"); | |
png_free(png_ptr, new_name); | |
return; | |
} | |
if (profile_len < embedded_profile_len) | |
{ | |
png_warning(png_ptr, | |
"Embedded profile length too large in iCCP chunk"); | |
png_free(png_ptr, new_name); | |
return; | |
} | |
if (profile_len > embedded_profile_len) | |
{ | |
png_warning(png_ptr, | |
"Truncating profile to actual length in iCCP chunk"); | |
profile_len = embedded_profile_len; | |
} | |
if (profile_len) | |
profile_len = png_text_compress(png_ptr, profile, | |
(png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp); | |
/* Make sure we include the NULL after the name and the compression type */ | |
png_write_chunk_start(png_ptr, png_iCCP, | |
(png_uint_32)(name_len + profile_len + 2)); | |
new_name[name_len + 1] = 0x00; | |
png_write_chunk_data(png_ptr, (png_bytep)new_name, | |
(png_size_t)(name_len + 2)); | |
if (profile_len) | |
{ | |
comp.input_len = profile_len; | |
png_write_compressed_data_out(png_ptr, &comp); | |
} | |
png_write_chunk_end(png_ptr); | |
png_free(png_ptr, new_name); | |
} | |
#endif | |
#ifdef PNG_WRITE_sPLT_SUPPORTED | |
/* Write a sPLT chunk */ | |
void /* PRIVATE */ | |
png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette) | |
{ | |
PNG_sPLT; | |
png_size_t name_len; | |
png_charp new_name; | |
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"); | |
if ((name_len = png_check_keyword(png_ptr,spalette->name, &new_name))==0) | |
return; | |
/* Make sure we include the NULL after the name */ | |
png_write_chunk_start(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, (png_size_t)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, (png_size_t)entry_size); | |
} | |
#endif | |
png_write_chunk_end(png_ptr); | |
png_free(png_ptr, new_name); | |
} | |
#endif | |
#ifdef PNG_WRITE_sBIT_SUPPORTED | |
/* Write the sBIT chunk */ | |
void /* PRIVATE */ | |
png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type) | |
{ | |
PNG_sBIT; | |
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_chunk(png_ptr, png_sBIT, buf, size); | |
} | |
#endif | |
#ifdef PNG_WRITE_cHRM_SUPPORTED | |
/* Write the cHRM chunk */ | |
void /* PRIVATE */ | |
png_write_cHRM_fixed(png_structp png_ptr, png_fixed_point white_x, | |
png_fixed_point white_y, png_fixed_point red_x, png_fixed_point red_y, | |
png_fixed_point green_x, png_fixed_point green_y, png_fixed_point blue_x, | |
png_fixed_point blue_y) | |
{ | |
PNG_cHRM; | |
png_byte buf[32]; | |
png_debug(1, "in png_write_cHRM"); | |
/* Each value is saved in 1/100,000ths */ | |
#ifdef PNG_CHECK_cHRM_SUPPORTED | |
if (png_check_cHRM_fixed(png_ptr, white_x, white_y, red_x, red_y, | |
green_x, green_y, blue_x, blue_y)) | |
#endif | |
{ | |
png_save_uint_32(buf, (png_uint_32)white_x); | |
png_save_uint_32(buf + 4, (png_uint_32)white_y); | |
png_save_uint_32(buf + 8, (png_uint_32)red_x); | |
png_save_uint_32(buf + 12, (png_uint_32)red_y); | |
png_save_uint_32(buf + 16, (png_uint_32)green_x); | |
png_save_uint_32(buf + 20, (png_uint_32)green_y); | |
png_save_uint_32(buf + 24, (png_uint_32)blue_x); | |
png_save_uint_32(buf + 28, (png_uint_32)blue_y); | |
png_write_chunk(png_ptr, png_cHRM, buf, (png_size_t)32); | |
} | |
} | |
#endif | |
#ifdef PNG_WRITE_tRNS_SUPPORTED | |
/* Write the tRNS chunk */ | |
void /* PRIVATE */ | |
png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, | |
png_const_color_16p tran, int num_trans, int color_type) | |
{ | |
PNG_tRNS; | |
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_warning(png_ptr, "Invalid number of transparent colors specified"); | |
return; | |
} | |
/* Write the chunk out as it is */ | |
png_write_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_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_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_warning(png_ptr, | |
"Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8"); | |
return; | |
} | |
png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)6); | |
} | |
else | |
{ | |
png_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_structp png_ptr, png_const_color_16p back, int color_type) | |
{ | |
PNG_bKGD; | |
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_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_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_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_structp png_ptr, png_const_uint_16p hist, int num_hist) | |
{ | |
PNG_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_start(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 | |
#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 is allocated to hold the corrected keyword and must be freed | |
* by the calling routine. This avoids problems with trying to write to | |
* static keywords without having to have duplicate copies of the strings. | |
*/ | |
png_size_t /* PRIVATE */ | |
png_check_keyword(png_structp png_ptr, png_const_charp key, png_charpp new_key) | |
{ | |
png_size_t key_len; | |
png_const_charp ikp; | |
png_charp kp, dp; | |
int kflag; | |
int kwarn=0; | |
png_debug(1, "in png_check_keyword"); | |
*new_key = NULL; | |
if (key == NULL || (key_len = png_strlen(key)) == 0) | |
{ | |
png_warning(png_ptr, "zero length keyword"); | |
return ((png_size_t)0); | |
} | |
png_debug1(2, "Keyword to be checked is '%s'", key); | |
*new_key = (png_charp)png_malloc_warn(png_ptr, (png_uint_32)(key_len + 2)); | |
if (*new_key == NULL) | |
{ | |
png_warning(png_ptr, "Out of memory while procesing keyword"); | |
return ((png_size_t)0); | |
} | |
/* Replace non-printing characters with a blank and print a warning */ | |
for (ikp = key, dp = *new_key; *ikp != '\0'; ikp++, dp++) | |
{ | |
if ((png_byte)*ikp < 0x20 || | |
((png_byte)*ikp > 0x7E && (png_byte)*ikp < 0xA1)) | |
{ | |
PNG_WARNING_PARAMETERS(p) | |
png_warning_parameter_unsigned(p, 1, PNG_NUMBER_FORMAT_02x, | |
(png_byte)*ikp); | |
png_formatted_warning(png_ptr, p, "invalid keyword character 0x@1"); | |
*dp = ' '; | |
} | |
else | |
{ | |
*dp = *ikp; | |
} | |
} | |
*dp = '\0'; | |
/* Remove any trailing white space. */ | |
kp = *new_key + key_len - 1; | |
if (*kp == ' ') | |
{ | |
png_warning(png_ptr, "trailing spaces removed from keyword"); | |
while (*kp == ' ') | |
{ | |
*(kp--) = '\0'; | |
key_len--; | |
} | |
} | |
/* Remove any leading white space. */ | |
kp = *new_key; | |
if (*kp == ' ') | |
{ | |
png_warning(png_ptr, "leading spaces removed from keyword"); | |
while (*kp == ' ') | |
{ | |
kp++; | |
key_len--; | |
} | |
} | |
png_debug1(2, "Checking for multiple internal spaces in '%s'", kp); | |
/* Remove multiple internal spaces. */ | |
for (kflag = 0, dp = *new_key; *kp != '\0'; kp++) | |
{ | |
if (*kp == ' ' && kflag == 0) | |
{ | |
*(dp++) = *kp; | |
kflag = 1; | |
} | |
else if (*kp == ' ') | |
{ | |
key_len--; | |
kwarn = 1; | |
} | |
else | |
{ | |
*(dp++) = *kp; | |
kflag = 0; | |
} | |
} | |
*dp = '\0'; | |
if (kwarn) | |
png_warning(png_ptr, "extra interior spaces removed from keyword"); | |
if (key_len == 0) | |
{ | |
png_free(png_ptr, *new_key); | |
png_warning(png_ptr, "Zero length keyword"); | |
} | |
if (key_len > 79) | |
{ | |
png_warning(png_ptr, "keyword length must be 1 - 79 characters"); | |
(*new_key)[79] = '\0'; | |
key_len = 79; | |
} | |
return (key_len); | |
} | |
#endif | |
#ifdef PNG_WRITE_tEXt_SUPPORTED | |
/* Write a tEXt chunk */ | |
void /* PRIVATE */ | |
png_write_tEXt(png_structp png_ptr, png_const_charp key, png_const_charp text, | |
png_size_t text_len) | |
{ | |
PNG_tEXt; | |
png_size_t key_len; | |
png_charp new_key; | |
png_debug(1, "in png_write_tEXt"); | |
if ((key_len = png_check_keyword(png_ptr, key, &new_key))==0) | |
return; | |
if (text == NULL || *text == '\0') | |
text_len = 0; | |
else | |
text_len = png_strlen(text); | |
/* Make sure we include the 0 after the key */ | |
png_write_chunk_start(png_ptr, png_tEXt, | |
(png_uint_32)(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, (png_bytep)new_key, | |
(png_size_t)(key_len + 1)); | |
if (text_len) | |
png_write_chunk_data(png_ptr, (png_const_bytep)text, | |
(png_size_t)text_len); | |
png_write_chunk_end(png_ptr); | |
png_free(png_ptr, new_key); | |
} | |
#endif | |
#ifdef PNG_WRITE_zTXt_SUPPORTED | |
/* Write a compressed text chunk */ | |
void /* PRIVATE */ | |
png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text, | |
png_size_t text_len, int compression) | |
{ | |
PNG_zTXt; | |
png_size_t key_len; | |
png_byte buf; | |
png_charp new_key; | |
compression_state comp; | |
png_debug(1, "in png_write_zTXt"); | |
comp.num_output_ptr = 0; | |
comp.max_output_ptr = 0; | |
comp.output_ptr = NULL; | |
comp.input = NULL; | |
comp.input_len = 0; | |
if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0) | |
{ | |
png_free(png_ptr, new_key); | |
return; | |
} | |
if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE) | |
{ | |
png_write_tEXt(png_ptr, new_key, text, (png_size_t)0); | |
png_free(png_ptr, new_key); | |
return; | |
} | |
text_len = png_strlen(text); | |
/* Compute the compressed data; do it now for the length */ | |
text_len = png_text_compress(png_ptr, text, text_len, compression, | |
&comp); | |
/* Write start of chunk */ | |
png_write_chunk_start(png_ptr, png_zTXt, | |
(png_uint_32)(key_len+text_len + 2)); | |
/* Write key */ | |
png_write_chunk_data(png_ptr, (png_bytep)new_key, | |
(png_size_t)(key_len + 1)); | |
png_free(png_ptr, new_key); | |
buf = (png_byte)compression; | |
/* Write compression */ | |
png_write_chunk_data(png_ptr, &buf, (png_size_t)1); | |
/* Write the compressed data */ | |
comp.input_len = text_len; | |
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_structp png_ptr, int compression, png_const_charp key, | |
png_const_charp lang, png_const_charp lang_key, png_const_charp text) | |
{ | |
PNG_iTXt; | |
png_size_t lang_len, key_len, lang_key_len, text_len; | |
png_charp new_lang; | |
png_charp new_key = NULL; | |
png_byte cbuf[2]; | |
compression_state comp; | |
png_debug(1, "in png_write_iTXt"); | |
comp.num_output_ptr = 0; | |
comp.max_output_ptr = 0; | |
comp.output_ptr = NULL; | |
comp.input = NULL; | |
if ((key_len = png_check_keyword(png_ptr, key, &new_key)) == 0) | |
return; | |
if ((lang_len = png_check_keyword(png_ptr, lang, &new_lang)) == 0) | |
{ | |
png_warning(png_ptr, "Empty language field in iTXt chunk"); | |
new_lang = NULL; | |
lang_len = 0; | |
} | |
if (lang_key == NULL) | |
lang_key_len = 0; | |
else | |
lang_key_len = png_strlen(lang_key); | |
if (text == NULL) | |
text_len = 0; | |
else | |
text_len = png_strlen(text); | |
/* Compute the compressed data; do it now for the length */ | |
text_len = png_text_compress(png_ptr, text, text_len, compression - 2, | |
&comp); | |
/* Make sure we include the compression flag, the compression byte, | |
* and the NULs after the key, lang, and lang_key parts | |
*/ | |
png_write_chunk_start(png_ptr, png_iTXt, (png_uint_32)( | |
5 /* comp byte, comp flag, terminators for key, lang and lang_key */ | |
+ key_len | |
+ lang_len | |
+ lang_key_len | |
+ text_len)); | |
/* 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, (png_bytep)new_key, (png_size_t)(key_len + 1)); | |
/* Set the compression flag */ | |
if (compression == PNG_ITXT_COMPRESSION_NONE || | |
compression == PNG_TEXT_COMPRESSION_NONE) | |
cbuf[0] = 0; | |
else /* compression == PNG_ITXT_COMPRESSION_zTXt */ | |
cbuf[0] = 1; | |
/* Set the compression method */ | |
cbuf[1] = 0; | |
png_write_chunk_data(png_ptr, cbuf, (png_size_t)2); | |
cbuf[0] = 0; | |
png_write_chunk_data(png_ptr, (new_lang ? (png_const_bytep)new_lang : cbuf), | |
(png_size_t)(lang_len + 1)); | |
png_write_chunk_data(png_ptr, (lang_key ? (png_const_bytep)lang_key : cbuf), | |
(png_size_t)(lang_key_len + 1)); | |
png_write_compressed_data_out(png_ptr, &comp); | |
png_write_chunk_end(png_ptr); | |
png_free(png_ptr, new_key); | |
png_free(png_ptr, new_lang); | |
} | |
#endif | |
#ifdef PNG_WRITE_oFFs_SUPPORTED | |
/* Write the oFFs chunk */ | |
void /* PRIVATE */ | |
png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset, | |
int unit_type) | |
{ | |
PNG_oFFs; | |
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_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_structp 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_pCAL; | |
png_size_t purpose_len, units_len, total_len; | |
png_uint_32p params_len; | |
png_byte buf[10]; | |
png_charp new_purpose; | |
int i; | |
png_debug1(1, "in png_write_pCAL (%d parameters)", nparams); | |
if (type >= PNG_EQUATION_LAST) | |
png_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); | |
purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1; | |
png_debug1(3, "pCAL purpose length = %d", (int)purpose_len); | |
units_len = png_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_uint_32p)png_malloc(png_ptr, | |
(png_alloc_size_t)(nparams * png_sizeof(png_uint_32))); | |
/* 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] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1); | |
png_debug2(3, "pCAL parameter %d length = %lu", i, | |
(unsigned long)params_len[i]); | |
total_len += (png_size_t)params_len[i]; | |
} | |
png_debug1(3, "pCAL total length = %d", (int)total_len); | |
png_write_chunk_start(png_ptr, png_pCAL, (png_uint_32)total_len); | |
png_write_chunk_data(png_ptr, (png_const_bytep)new_purpose, | |
(png_size_t)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); | |
png_free(png_ptr, new_purpose); | |
for (i = 0; i < nparams; i++) | |
{ | |
png_write_chunk_data(png_ptr, (png_const_bytep)params[i], | |
(png_size_t)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_structp png_ptr, int unit, png_const_charp width, | |
png_const_charp height) | |
{ | |
PNG_sCAL; | |
png_byte buf[64]; | |
png_size_t wlen, hlen, total_len; | |
png_debug(1, "in png_write_sCAL_s"); | |
wlen = png_strlen(width); | |
hlen = png_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; | |
png_memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */ | |
png_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_chunk(png_ptr, png_sCAL, buf, total_len); | |
} | |
#endif | |
#ifdef PNG_WRITE_pHYs_SUPPORTED | |
/* Write the pHYs chunk */ | |
void /* PRIVATE */ | |
png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, | |
png_uint_32 y_pixels_per_unit, | |
int unit_type) | |
{ | |
PNG_pHYs; | |
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_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_structp png_ptr, png_const_timep mod_time) | |
{ | |
PNG_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_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_structp png_ptr) | |
{ | |
#ifdef PNG_WRITE_INTERLACING_SUPPORTED | |
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ | |
/* Start of interlace block */ | |
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; | |
/* Offset to next interlace block */ | |
int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; | |
/* Start of interlace block in the y direction */ | |
int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; | |
/* Offset to next interlace block in the y direction */ | |
int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; | |
#endif | |
png_size_t buf_size; | |
png_debug(1, "in png_write_start_row"); | |
buf_size = (png_size_t)(PNG_ROWBYTES( | |
png_ptr->usr_channels*png_ptr->usr_bit_depth, png_ptr->width) + 1); | |
/* Set up row buffer */ | |
png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, | |
(png_alloc_size_t)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, | |
(png_alloc_size_t)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; | |
} | |
png_zlib_claim(png_ptr, PNG_ZLIB_FOR_IDAT); | |
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; | |
png_ptr->zstream.next_out = png_ptr->zbuf; | |
} | |
/* Internal use only. Called when finished processing a row of data. */ | |
void /* PRIVATE */ | |
png_write_finish_row(png_structp png_ptr) | |
{ | |
#ifdef PNG_WRITE_INTERLACING_SUPPORTED | |
/* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ | |
/* Start of interlace block */ | |
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; | |
/* Offset to next interlace block */ | |
int png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1}; | |
/* Start of interlace block in the y direction */ | |
int png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1}; | |
/* Offset to next interlace block in the y direction */ | |
int png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; | |
#endif | |
int ret; | |
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) | |
png_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 */ | |
do | |
{ | |
/* Tell the compressor we are done */ | |
ret = deflate(&png_ptr->zstream, Z_FINISH); | |
/* Check for an error */ | |
if (ret == Z_OK) | |
{ | |
/* Check to see if we need more room */ | |
if (!(png_ptr->zstream.avail_out)) | |
{ | |
png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); | |
png_ptr->zstream.next_out = png_ptr->zbuf; | |
png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; | |
} | |
} | |
else if (ret != Z_STREAM_END) | |
{ | |
if (png_ptr->zstream.msg != NULL) | |
png_error(png_ptr, png_ptr->zstream.msg); | |
else | |
png_error(png_ptr, "zlib error"); | |
} | |
} while (ret != Z_STREAM_END); | |
/* Write any extra space */ | |
if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) | |
{ | |
png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size - | |
png_ptr->zstream.avail_out); | |
} | |
png_zlib_release(png_ptr); | |
png_ptr->zstream.data_type = Z_BINARY; | |
} | |
#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 */ | |
int png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0}; | |
/* Offset to next interlace block */ | |
int 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) | |
png_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_structp png_ptr, png_bytep filtered_row); | |
#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_structp 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 = (int)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); | |
#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_structp png_ptr, png_bytep filtered_row) | |
{ | |
png_size_t avail; | |
png_debug(1, "in png_write_filtered_row"); | |
png_debug1(2, "filter = %d", filtered_row[0]); | |
/* Set up the zlib input buffer */ | |
png_ptr->zstream.next_in = filtered_row; | |
png_ptr->zstream.avail_in = 0; | |
avail = png_ptr->row_info.rowbytes + 1; | |
/* Repeat until we have compressed all the data */ | |
do | |
{ | |
int ret; /* Return of zlib */ | |
/* Record the number of bytes available - zlib supports at least 65535 | |
* bytes at one step, depending on the size of the zlib type 'uInt', the | |
* maximum size zlib can write at once is ZLIB_IO_MAX (from pngpriv.h). | |
* Use this because on 16 bit systems 'rowbytes' can be up to 65536 (i.e. | |
* one more than 16 bits) and, in this case 'rowbytes+1' can overflow a | |
* uInt. ZLIB_IO_MAX can be safely reduced to cause zlib to be called | |
* with smaller chunks of data. | |
*/ | |
if (png_ptr->zstream.avail_in == 0) | |
{ | |
if (avail > ZLIB_IO_MAX) | |
{ | |
png_ptr->zstream.avail_in = ZLIB_IO_MAX; | |
avail -= ZLIB_IO_MAX; | |
} | |
else | |
{ | |
/* So this will fit in the available uInt space: */ | |
png_ptr->zstream.avail_in = (uInt)avail; | |
avail = 0; | |
} | |
} | |
/* Compress the data */ | |
ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); | |
/* Check for compression errors */ | |
if (ret != Z_OK) | |
{ | |
if (png_ptr->zstream.msg != NULL) | |
png_error(png_ptr, png_ptr->zstream.msg); | |
else | |
png_error(png_ptr, "zlib error"); | |
} | |
/* See if it is time to write another IDAT */ | |
if (!(png_ptr->zstream.avail_out)) | |
{ | |
/* Write the IDAT and reset the zlib output buffer */ | |
png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); | |
} | |
/* Repeat until all data has been compressed */ | |
} while (avail > 0 || png_ptr->zstream.avail_in > 0); | |
/* 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 */ |