diff options
Diffstat (limited to 'drivers/png/pngwutil.c')
| -rw-r--r-- | drivers/png/pngwutil.c | 2119 |
1 files changed, 1032 insertions, 1087 deletions
diff --git a/drivers/png/pngwutil.c b/drivers/png/pngwutil.c index d5f097fb97..b47f119d22 100644 --- a/drivers/png/pngwutil.c +++ b/drivers/png/pngwutil.c @@ -1,8 +1,8 @@ /* pngwutil.c - utilities to write a PNG file * - * Last changed in libpng 1.5.26 [December 17, 2015] - * Copyright (c) 1998-2002,2004,2006-2015 Glenn Randers-Pehrson + * Last changed in libpng 1.6.22 [May 26, 2016] + * Copyright (c) 1998-2002,2004,2006-2016 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.) * @@ -23,30 +23,12 @@ 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); + buf[0] = (png_byte)((i >> 24) & 0xffU); + buf[1] = (png_byte)((i >> 16) & 0xffU); + buf[2] = (png_byte)((i >> 8) & 0xffU); + buf[3] = (png_byte)( i & 0xffU); } -#ifdef PNG_SAVE_INT_32_SUPPORTED -/* PNG signed integers are saved in 32-bit 2's complement format. ANSI C-90 - * defines a cast of a signed integer to an unsigned integer either to preserve - * the value, if it is positive, or to calculate: - * - * (UNSIGNED_MAX+1) + integer - * - * Where UNSIGNED_MAX is the appropriate maximum unsigned value, so when the - * negative integral value is added the result will be an unsigned value - * correspnding to the 2's complement representation. - */ -void PNGAPI -png_save_int_32(png_bytep buf, png_int_32 i) -{ - png_save_uint_32(buf, i); -} -#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. @@ -54,8 +36,8 @@ png_save_int_32(png_bytep buf, png_int_32 i) 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); + buf[0] = (png_byte)((i >> 8) & 0xffU); + buf[1] = (png_byte)( i & 0xffU); } #endif @@ -66,7 +48,7 @@ png_save_uint_16(png_bytep buf, unsigned int i) * bytes have already been written. */ void PNGAPI -png_write_sig(png_structp png_ptr) +png_write_sig(png_structrp png_ptr) { png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10}; @@ -88,7 +70,7 @@ png_write_sig(png_structp png_ptr) * passing in png_write_chunk_data(). */ static void -png_write_chunk_header(png_structp png_ptr, png_uint_32 chunk_name, +png_write_chunk_header(png_structrp png_ptr, png_uint_32 chunk_name, png_uint_32 length) { png_byte buf[8]; @@ -130,7 +112,7 @@ png_write_chunk_header(png_structp png_ptr, png_uint_32 chunk_name, } void PNGAPI -png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_string, +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); @@ -142,7 +124,7 @@ png_write_chunk_start(png_structp png_ptr, png_const_bytep chunk_string, * given to png_write_chunk_header(). */ void PNGAPI -png_write_chunk_data(png_structp png_ptr, png_const_bytep data, +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 */ @@ -154,7 +136,7 @@ png_write_chunk_data(png_structp png_ptr, png_const_bytep data, png_write_data(png_ptr, data, length); /* Update the CRC after writing the data, - * in case that the user I/O routine alters it. + * in case the user I/O routine alters it. */ png_calculate_crc(png_ptr, data, length); } @@ -162,7 +144,7 @@ png_write_chunk_data(png_structp png_ptr, png_const_bytep data, /* Finish a chunk started with png_write_chunk_header(). */ void PNGAPI -png_write_chunk_end(png_structp png_ptr) +png_write_chunk_end(png_structrp png_ptr) { png_byte buf[4]; @@ -191,15 +173,15 @@ png_write_chunk_end(png_structp png_ptr) * functions instead. */ static void -png_write_complete_chunk(png_structp png_ptr, png_uint_32 chunk_name, +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_32_MAX) - png_error(png_ptr, "length exceeds PNG maxima"); + /* 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 maximum"); png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length); png_write_chunk_data(png_ptr, data, length); @@ -208,473 +190,487 @@ png_write_complete_chunk(png_structp png_ptr, png_uint_32 chunk_name, /* This is the API that calls the internal function above. */ void PNGAPI -png_write_chunk(png_structp png_ptr, png_const_bytep chunk_string, +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); } -/* Initialize the compressor for the appropriate type of compression. */ -static void -png_zlib_claim(png_structp png_ptr, png_uint_32 state) +/* 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) { - if (!(png_ptr->zlib_state & PNG_ZLIB_IN_USE)) + /* 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 already initialized for 'state' do not re-init. */ - if (png_ptr->zlib_state != state) + if (png_ptr->interlaced != 0) { - 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; - } + /* 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; - /* zlib itself detects an incomplete state on deflateEnd */ - if (ret == Z_OK) switch (state) + for (cb_base=0, pass=0; pass<=6; ++pass) { -# 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 + png_uint_32 pw = PNG_PASS_COLS(w, pass); - 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 (pw > 0) + cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass); } - 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); - } + return cb_base; } - /* Here on success, claim the zstream: */ - png_ptr->zlib_state |= PNG_ZLIB_IN_USE; + else + return (png_ptr->rowbytes+1) * h; } else - png_error(png_ptr, "zstream already in use (internal error)"); + return 0xffffffffU; } -/* The opposite: release the stream. It is also reset, this API will warn on - * error but will not fail. - */ +#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 -png_zlib_release(png_structp png_ptr) +optimize_cmf(png_bytep data, png_alloc_size_t data_size) { - if (png_ptr->zlib_state & PNG_ZLIB_IN_USE) + /* 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 */ { - int ret = deflateReset(&png_ptr->zstream); - - png_ptr->zlib_state &= ~PNG_ZLIB_IN_USE; + unsigned int z_cmf = data[0]; /* zlib compression method and flags */ - if (ret != Z_OK) + if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) { -#ifdef PNG_WARNINGS_SUPPORTED - png_const_charp err; - PNG_WARNING_PARAMETERS(p) + unsigned int z_cinfo; + unsigned int half_z_window_size; - switch (ret) + z_cinfo = z_cmf >> 4; + half_z_window_size = 1U << (z_cinfo + 7); + + if (data_size <= half_z_window_size) /* else no change */ { - case Z_VERSION_ERROR: - err = "version"; - break; + unsigned int tmp; - case Z_STREAM_ERROR: - err = "stream"; - break; + do + { + half_z_window_size >>= 1; + --z_cinfo; + } + while (z_cinfo > 0 && data_size <= half_z_window_size); - case Z_MEM_ERROR: - err = "memory"; - break; + z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); - default: - err = "unknown"; - break; + data[0] = (png_byte)z_cmf; + tmp = data[1] & 0xe0; + tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f; + data[1] = (png_byte)tmp; } - - 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"); -#endif } } - - else - png_warning(png_ptr, "zstream not in use (internal error)"); } +#endif /* WRITE_OPTIMIZE_CMF */ -#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) +/* 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) { - int ret; + if (png_ptr->zowner != 0) + { +#if defined(PNG_WARNINGS_SUPPORTED) || defined(PNG_ERROR_TEXT_SUPPORTED) + 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"); +#endif +#if PNG_RELEASE_BUILD + png_warning(png_ptr, msg); - comp->num_output_ptr = 0; - comp->max_output_ptr = 0; - comp->output_ptr = NULL; - comp->input = NULL; - comp->input_len = text_len; + /* 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; + } - /* 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); + png_ptr->zowner = 0; +#else + png_error(png_ptr, msg); +#endif } - 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"); - } + 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 */ - /* 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); + if (owner == png_IDAT) + { + if ((png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY) != 0) + strategy = png_ptr->zlib_strategy; - /* Set up the compression buffers */ - /* TODO: the following cast hides a potential overflow problem. */ - png_ptr->zstream.avail_in = (uInt)text_len; + else if (png_ptr->do_filter != PNG_FILTER_NONE) + strategy = PNG_Z_DEFAULT_STRATEGY; - /* 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; + else + strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY; + } - /* This is the same compression loop as in png_write_row() */ - do - { - /* Compress the data */ - ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); + 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 + } - if (ret != Z_OK) + /* 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) { - /* Error */ - if (png_ptr->zstream.msg != NULL) - png_error(png_ptr, png_ptr->zstream.msg); + /* 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); - else - png_error(png_ptr, "zlib error"); + while (data_size + 262 <= half_window_size) + { + half_window_size >>= 1; + --windowBits; + } } - /* Check to see if we need more room */ - if (!(png_ptr->zstream.avail_out)) + /* Check against the previous initialized values, if any. */ + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0 && + (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)) { - /* Make sure the output array has room */ - if (comp->num_output_ptr >= comp->max_output_ptr) - { - int old_max; + if (deflateEnd(&png_ptr->zstream) != Z_OK) + png_warning(png_ptr, "deflateEnd failed (ignored)"); - old_max = comp->max_output_ptr; - comp->max_output_ptr = comp->num_output_ptr + 4; - if (comp->output_ptr != NULL) - { - png_bytepp old_ptr; + png_ptr->flags &= ~PNG_FLAG_ZSTREAM_INITIALIZED; + } - old_ptr = comp->output_ptr; + /* 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; - comp->output_ptr = (png_bytepp)png_malloc(png_ptr, - (comp->max_output_ptr * png_sizeof(png_bytep))); + /* 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) != 0) + ret = deflateReset(&png_ptr->zstream); - png_memcpy(comp->output_ptr, old_ptr, old_max - * png_sizeof(png_bytep)); + else + { + ret = deflateInit2(&png_ptr->zstream, level, method, windowBits, + memLevel, strategy); - png_free(png_ptr, old_ptr); - } - else - comp->output_ptr = (png_bytepp)png_malloc(png_ptr, - (comp->max_output_ptr * png_sizeof(png_bytep))); - } + if (ret == Z_OK) + png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED; + } - /* Save the data */ - comp->output_ptr[comp->num_output_ptr] = - (png_bytep)png_malloc(png_ptr, png_ptr->zbuf_size); + /* 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; - png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, - png_ptr->zbuf_size); + else + png_zstream_error(png_ptr, ret); - comp->num_output_ptr++; + return ret; + } +} - /* 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); +/* 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; - /* Finish the compression */ - do + if (list != NULL) { - /* Tell zlib we are finished */ - ret = deflate(&png_ptr->zstream, Z_FINISH); + *listp = NULL; - if (ret == Z_OK) + do { - /* 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; + png_compression_bufferp next = list->next; - old_max = comp->max_output_ptr; - comp->max_output_ptr = comp->num_output_ptr + 4; - if (comp->output_ptr != NULL) - { - png_bytepp old_ptr; + png_free(png_ptr, list); + list = next; + } + while (list != NULL); + } +} - old_ptr = comp->output_ptr; +#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; - /* 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))); +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; +} - png_memcpy(comp->output_ptr, old_ptr, - old_max * png_sizeof(png_charp)); +/* 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; - png_free(png_ptr, old_ptr); - } + /* 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); - else - comp->output_ptr = (png_bytepp)png_malloc(png_ptr, - (png_alloc_size_t)(comp->max_output_ptr * - png_sizeof(png_charp))); - } + if (ret != Z_OK) + return ret; - /* Save the data */ - comp->output_ptr[comp->num_output_ptr] = - (png_bytep)png_malloc(png_ptr, - (png_alloc_size_t)png_ptr->zbuf_size); + /* 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; - png_memcpy(comp->output_ptr[comp->num_output_ptr], png_ptr->zbuf, - png_ptr->zbuf_size); + /* 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); - comp->num_output_ptr++; + output_len = png_ptr->zstream.avail_out; - /* 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) + do { - /* We got an error */ - if (png_ptr->zstream.msg != NULL) - png_error(png_ptr, png_ptr->zstream.msg); + uInt avail_in = ZLIB_IO_MAX; - else - png_error(png_ptr, "zlib error"); - } - } while (ret != Z_STREAM_END); + if (avail_in > input_len) + avail_in = (uInt)input_len; - /* Text length is number of buffers plus last buffer */ - text_len = png_ptr->zbuf_size * comp->num_output_ptr; + input_len -= avail_in; - if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) - text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out; + png_ptr->zstream.avail_in = avail_in; - 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, - png_size_t data_len) -{ - int i; + if (png_ptr->zstream.avail_out == 0) + { + png_compression_buffer *next; - /* Handle the no-compression case */ - if (comp->input) - { - png_write_chunk_data(png_ptr, comp->input, data_len); + /* 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; + } - return; - } + /* 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))); -#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED - /* The zbuf_size test is because the code below doesn't work if zbuf_size is - * '1'; simply skip it to avoid memory overwrite. - */ - if (data_len >= 2 && comp->input_len < 16384 && png_ptr->zbuf_size > 1) - { - unsigned int z_cmf; /* zlib compression method and flags */ + if (next == NULL) + { + ret = Z_MEM_ERROR; + break; + } - /* Optimize the CMF field in the zlib stream. This hack of the zlib - * stream is compliant to the stream specification. - */ + /* Link in this buffer (so that it will be freed later) */ + next->next = NULL; + *end = next; + } - if (comp->num_output_ptr) - z_cmf = comp->output_ptr[0][0]; - else - z_cmf = png_ptr->zbuf[0]; + png_ptr->zstream.next_out = next->output; + png_ptr->zstream.avail_out = png_ptr->zbuffer_size; + output_len += png_ptr->zstream.avail_out; - 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; + /* Move 'end' to the next buffer pointer. */ + end = &next->next; + } - z_cinfo = z_cmf >> 4; - half_z_window_size = 1 << (z_cinfo + 7); + /* Compress the data */ + ret = deflate(&png_ptr->zstream, + input_len > 0 ? Z_NO_FLUSH : Z_FINISH); - while (uncompressed_text_size <= half_z_window_size && - half_z_window_size >= 256) - { - z_cinfo--; - half_z_window_size >>= 1; - } + /* 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); - z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); + /* 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; - if (comp->num_output_ptr) - { + /* 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; + } - if (comp->output_ptr[0][0] != z_cmf) - { - int tmp; + else + png_zstream_error(png_ptr, ret); - 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; + /* Reset zlib for another zTXt/iTXt or image data */ + png_ptr->zowner = 0; - 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; - } + /* 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) + { +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + /* Fix up the deflate header, if required */ + optimize_cmf(comp->output, comp->input_len); +#endif + /* 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 - png_error(png_ptr, - "Invalid zlib compression method or flags in non-IDAT chunk"); + return ret; } -#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */ +} + +/* 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; - /* Write saved output buffers, if any */ - for (i = 0; i < comp->num_output_ptr; i++) + for (;;) { - png_write_chunk_data(png_ptr, comp->output_ptr[i], - (png_size_t)png_ptr->zbuf_size); + if (avail > output_len) + avail = output_len; - png_free(png_ptr, comp->output_ptr[i]); - } + png_write_chunk_data(png_ptr, output, avail); - if (comp->max_output_ptr != 0) - png_free(png_ptr, comp->output_ptr); + output_len -= avail; - /* 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)); + if (output_len == 0 || next == NULL) + break; + + avail = png_ptr->zbuffer_size; + output = next->output; + next = next->next; + } - /* Reset zlib for another zTXt/iTXt or image data */ - png_zlib_release(png_ptr); + /* 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 */ +#endif /* WRITE_COMPRESSED_TEXT */ /* 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, +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) { @@ -768,8 +764,8 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, */ if ( #ifdef PNG_MNG_FEATURES_SUPPORTED - !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) && - ((png_ptr->mode&PNG_HAVE_PNG_SIGNATURE) == 0) && + !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 0 && + ((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)) && @@ -791,7 +787,7 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, interlace_type=PNG_INTERLACE_NONE; #endif - /* Save the relevent information */ + /* Save the relevant information */ png_ptr->bit_depth = (png_byte)bit_depth; png_ptr->color_type = (png_byte)color_type; png_ptr->interlaced = (png_byte)interlace_type; @@ -821,11 +817,6 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, /* Write the chunk */ png_write_complete_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) == PNG_NO_FILTERS) { if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE || @@ -836,55 +827,6 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, 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 */ } @@ -893,7 +835,7 @@ png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, * structure. */ void /* PRIVATE */ -png_write_PLTE(png_structp png_ptr, png_const_colorp palette, +png_write_PLTE(png_structrp png_ptr, png_const_colorp palette, png_uint_32 num_pal) { png_uint_32 max_palette_length, i; @@ -907,7 +849,7 @@ png_write_PLTE(png_structp png_ptr, png_const_colorp palette, if (( #ifdef PNG_MNG_FEATURES_SUPPORTED - !(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) && + (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0 && #endif num_pal == 0) || num_pal > max_palette_length) { @@ -923,7 +865,7 @@ png_write_PLTE(png_structp png_ptr, png_const_colorp palette, } } - if (!(png_ptr->color_type&PNG_COLOR_MASK_COLOR)) + if ((png_ptr->color_type & PNG_COLOR_MASK_COLOR) == 0) { png_warning(png_ptr, "Ignoring request to write a PLTE chunk in grayscale PNG"); @@ -964,94 +906,165 @@ png_write_PLTE(png_structp png_ptr, png_const_colorp palette, png_ptr->mode |= PNG_HAVE_PLTE; } -/* Write an IDAT chunk */ +/* 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_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length) +png_compress_IDAT(png_structrp png_ptr, png_const_bytep input, + png_alloc_size_t input_len, int flush) { - png_debug(1, "in png_write_IDAT"); + 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; + } -#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED - if (!(png_ptr->mode & PNG_HAVE_IDAT) && - png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) + 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 (;;) { - /* Optimize the CMF field in the zlib stream. This hack of the zlib - * stream is compliant to the stream specification. + 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. */ - unsigned int z_cmf = data[0]; /* zlib compression method and flags */ + if (png_ptr->zstream.avail_out == 0) + { + png_bytep data = png_ptr->zbuffer_list->output; + uInt size = png_ptr->zbuffer_size; - if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70) + /* 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) == 0 && + 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 affects which + * possible error might be detected if multiple things go wrong at once. + */ + if (ret == Z_OK) /* most likely return code! */ { - /* Avoid memory underflows and multiplication overflows. - * - * The conditions below are practically always satisfied; - * however, they still must be checked. + /* 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 (length >= 2 && - png_ptr->height < 16384 && png_ptr->width < 16384) + if (input_len == 0) { - /* Compute the maximum possible length of the datastream */ + if (flush == Z_FINISH) + png_error(png_ptr, "Z_OK on Z_FINISH with output space"); - /* 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); + return; + } + } - z_cinfo = z_cmf >> 4; - half_z_window_size = 1 << (z_cinfo + 7); + 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; - while (uncompressed_idat_size <= half_z_window_size && - half_z_window_size >= 256) - { - z_cinfo--; - half_z_window_size >>= 1; - } +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED + if ((png_ptr->mode & PNG_HAVE_IDAT) == 0 && + png_ptr->compression_type == PNG_COMPRESSION_TYPE_BASE) + optimize_cmf(data, png_image_size(png_ptr)); +#endif - z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4); + 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; - 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; - } - } + png_ptr->zowner = 0; /* Release the stream */ + return; } else - png_error(png_ptr, - "Invalid zlib compression method or flags in IDAT"); + { + /* This is an error condition. */ + png_zstream_error(png_ptr, ret); + png_error(png_ptr, png_ptr->zstream.msg); + } } -#endif /* PNG_WRITE_OPTIMIZE_CMF_SUPPORTED */ - - png_write_complete_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_write_IEND(png_structrp png_ptr) { png_debug(1, "in png_write_IEND"); @@ -1062,7 +1075,7 @@ png_write_IEND(png_structp png_ptr) #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_write_gAMA_fixed(png_structrp png_ptr, png_fixed_point file_gamma) { png_byte buf[4]; @@ -1077,7 +1090,7 @@ png_write_gAMA_fixed(png_structp png_ptr, png_fixed_point file_gamma) #ifdef PNG_WRITE_sRGB_SUPPORTED /* Write a sRGB chunk */ void /* PRIVATE */ -png_write_sRGB(png_structp png_ptr, int srgb_intent) +png_write_sRGB(png_structrp png_ptr, int srgb_intent) { png_byte buf[1]; @@ -1095,79 +1108,60 @@ png_write_sRGB(png_structp png_ptr, int srgb_intent) #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_write_iCCP(png_structrp png_ptr, png_const_charp name, + png_const_bytep profile) { - png_size_t name_len; + png_uint_32 name_len; + png_uint_32 profile_len; + png_byte new_name[81]; /* 1 byte for the compression byte */ compression_state comp; - int embedded_profile_len = 0; + png_uint_32 temp; 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; - - name_len = png_strlen(name); + /* 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 */ - if (compression_type != PNG_COMPRESSION_TYPE_BASE) - png_warning(png_ptr, "Unknown compression type in iCCP chunk"); + profile_len = png_get_uint_32(profile); - if (profile == NULL) - profile_len = 0; + if (profile_len < 132) + png_error(png_ptr, "ICC profile too short"); - 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)) ); + 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)"); - if (embedded_profile_len < 0) { - png_warning(png_ptr, - "Embedded profile length in iCCP chunk is negative"); - return; - } + png_uint_32 embedded_profile_len = png_get_uint_32(profile); - if (profile_len < embedded_profile_len) - { - png_warning(png_ptr, - "Embedded profile length too large in iCCP chunk"); - return; + if (profile_len != embedded_profile_len) + png_error(png_ptr, "Profile length does not match profile"); } - if (profile_len > embedded_profile_len) - { - png_warning(png_ptr, - "Truncating profile to actual length in iCCP chunk"); + name_len = png_check_keyword(png_ptr, name, new_name); - profile_len = embedded_profile_len; - } + if (name_len == 0) + png_error(png_ptr, "iCCP: invalid keyword"); - if (profile_len != 0) - profile_len = png_text_compress(png_ptr, profile, - (png_size_t)profile_len, PNG_COMPRESSION_TYPE_BASE, &comp); + new_name[++name_len] = PNG_COMPRESSION_TYPE_BASE; /* Make sure we include the NULL after the name and the compression type */ - png_write_chunk_header(png_ptr, png_iCCP, - (png_uint_32)(name_len + profile_len + 2)); + ++name_len; - png_write_chunk_data(png_ptr, (png_bytep)name, name_len); + png_text_compress_init(&comp, profile, profile_len); - { - png_byte buffer[2]; - buffer[0] = 0; /* terminate name */ - buffer[1] = 0xFFU & compression_type; - png_write_chunk_data(png_ptr, buffer, 2); - } + /* 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); - if (profile_len != 0) - { - png_write_compressed_data_out(png_ptr, &comp, profile_len); - } + 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); } @@ -1176,9 +1170,10 @@ png_write_iCCP(png_structp png_ptr, png_const_charp name, int compression_type, #ifdef PNG_WRITE_sPLT_SUPPORTED /* Write a sPLT chunk */ void /* PRIVATE */ -png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette) +png_write_sPLT(png_structrp png_ptr, png_const_sPLT_tp spalette) { - png_size_t name_len; + 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; @@ -1189,13 +1184,16 @@ png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette) png_debug(1, "in png_write_sPLT"); - name_len = png_strlen(spalette->name); + 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)spalette->name, + 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); @@ -1222,7 +1220,7 @@ png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette) png_save_uint_16(entrybuf + 8, ep->frequency); } - png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size); + png_write_chunk_data(png_ptr, entrybuf, entry_size); } #else ep=spalette->entries; @@ -1246,7 +1244,7 @@ png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette) png_save_uint_16(entrybuf + 8, ep[i].frequency); } - png_write_chunk_data(png_ptr, entrybuf, (png_size_t)entry_size); + png_write_chunk_data(png_ptr, entrybuf, entry_size); } #endif @@ -1257,7 +1255,7 @@ png_write_sPLT(png_structp png_ptr, png_const_sPLT_tp spalette) #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_write_sBIT(png_structrp png_ptr, png_const_color_8p sbit, int color_type) { png_byte buf[4]; png_size_t size; @@ -1265,7 +1263,7 @@ png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type) 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) + if ((color_type & PNG_COLOR_MASK_COLOR) != 0) { png_byte maxbits; @@ -1298,7 +1296,7 @@ png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type) size = 1; } - if (color_type & PNG_COLOR_MASK_ALPHA) + if ((color_type & PNG_COLOR_MASK_ALPHA) != 0) { if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth) { @@ -1316,42 +1314,33 @@ png_write_sBIT(png_structp png_ptr, png_const_color_8p sbit, int color_type) #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_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 */ -#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_int_32(buf, xy->whitex); + png_save_int_32(buf + 4, xy->whitey); - png_save_uint_32(buf + 8, (png_uint_32)red_x); - png_save_uint_32(buf + 12, (png_uint_32)red_y); + png_save_int_32(buf + 8, xy->redx); + png_save_int_32(buf + 12, xy->redy); - png_save_uint_32(buf + 16, (png_uint_32)green_x); - png_save_uint_32(buf + 20, (png_uint_32)green_y); + png_save_int_32(buf + 16, xy->greenx); + png_save_int_32(buf + 20, xy->greeny); - png_save_uint_32(buf + 24, (png_uint_32)blue_x); - png_save_uint_32(buf + 28, (png_uint_32)blue_y); + 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, (png_size_t)32); - } + 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_structp png_ptr, png_const_bytep trans_alpha, +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]; @@ -1362,7 +1351,8 @@ png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, { if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette) { - png_warning(png_ptr, "Invalid number of transparent colors specified"); + png_app_warning(png_ptr, + "Invalid number of transparent colors specified"); return; } @@ -1373,10 +1363,10 @@ png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, else if (color_type == PNG_COLOR_TYPE_GRAY) { - /* One 16 bit value */ + /* One 16-bit value */ if (tran->gray >= (1 << png_ptr->bit_depth)) { - png_warning(png_ptr, + png_app_warning(png_ptr, "Ignoring attempt to write tRNS chunk out-of-range for bit_depth"); return; @@ -1388,17 +1378,17 @@ png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, else if (color_type == PNG_COLOR_TYPE_RGB) { - /* Three 16 bit values */ + /* 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])) + if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0) #else - if (buf[0] | buf[2] | buf[4]) + if ((buf[0] | buf[2] | buf[4]) != 0) #endif { - png_warning(png_ptr, + png_app_warning(png_ptr, "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8"); return; } @@ -1408,7 +1398,7 @@ png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, else { - png_warning(png_ptr, "Can't write tRNS with an alpha channel"); + png_app_warning(png_ptr, "Can't write tRNS with an alpha channel"); } } #endif @@ -1416,7 +1406,7 @@ png_write_tRNS(png_structp png_ptr, png_const_bytep trans_alpha, #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_write_bKGD(png_structrp png_ptr, png_const_color_16p back, int color_type) { png_byte buf[6]; @@ -1426,8 +1416,8 @@ png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type) { if ( #ifdef PNG_MNG_FEATURES_SUPPORTED - (png_ptr->num_palette || - (!(png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE))) && + (png_ptr->num_palette != 0 || + (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0) && #endif back->index >= png_ptr->num_palette) { @@ -1439,15 +1429,15 @@ png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type) png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1); } - else if (color_type & PNG_COLOR_MASK_COLOR) + else if ((color_type & PNG_COLOR_MASK_COLOR) != 0) { 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])) + if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0) #else - if (buf[0] | buf[2] | buf[4]) + if ((buf[0] | buf[2] | buf[4]) != 0) #endif { png_warning(png_ptr, @@ -1478,7 +1468,7 @@ png_write_bKGD(png_structp png_ptr, png_const_color_16p back, int color_type) #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_write_hIST(png_structrp png_ptr, png_const_uint_16p hist, int num_hist) { int i; png_byte buf[3]; @@ -1509,36 +1499,41 @@ png_write_hIST(png_structp png_ptr, png_const_uint_16p hist, int num_hist) #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_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text, png_size_t text_len) { - png_size_t key_len; + png_uint_32 key_len; + png_byte new_key[80]; png_debug(1, "in png_write_tEXt"); - key_len = strlen(key); + 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 = png_strlen(text); + 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)(key_len + text_len + 1)); + (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, (png_bytep)key, - (png_size_t)(key_len + 1)); + 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, - (png_size_t)text_len); + png_write_chunk_data(png_ptr, (png_const_bytep)text, text_len); png_write_chunk_end(png_ptr); } @@ -1547,50 +1542,48 @@ png_write_tEXt(png_structp png_ptr, png_const_charp key, png_const_charp text, #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_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text, + int compression) { - png_size_t key_len; - png_byte buf; + png_uint_32 key_len; + png_byte new_key[81]; 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; - - key_len = strlen(key); - - if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE) + if (compression == PNG_TEXT_COMPRESSION_NONE) { - png_write_tEXt(png_ptr, key, text, (png_size_t)0); + png_write_tEXt(png_ptr, key, text, 0); return; } - text_len = png_strlen(text); + 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 */ - text_len = png_text_compress(png_ptr, text, text_len, compression, - &comp); + 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, - (png_uint_32)(key_len+text_len + 2)); + png_write_chunk_header(png_ptr, png_zTXt, key_len + comp.output_len); /* Write key */ - png_write_chunk_data(png_ptr, (png_bytep)key, - (png_size_t)(key_len + 1)); - - buf = (png_byte)compression; - - /* Write compression */ - png_write_chunk_data(png_ptr, &buf, (png_size_t)1); + png_write_chunk_data(png_ptr, new_key, key_len); /* Write the compressed data */ - png_write_compressed_data_out(png_ptr, &comp, text_len); + png_write_compressed_data_out(png_ptr, &comp); /* Close the chunk */ png_write_chunk_end(png_ptr); @@ -1600,84 +1593,98 @@ png_write_zTXt(png_structp png_ptr, png_const_charp key, png_const_charp text, #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_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_size_t lang_len, key_len, lang_key_len, text_len; - png_byte cbuf[2]; + 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"); - comp.num_output_ptr = 0; - comp.max_output_ptr = 0; - comp.output_ptr = NULL; - comp.input = NULL; - - key_len = png_strlen(key); + key_len = png_check_keyword(png_ptr, key, new_key); - if (lang == NULL) - lang_len = 0; + if (key_len == 0) + png_error(png_ptr, "iTXt: invalid keyword"); - else - lang_len = png_strlen(lang); + /* 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; - if (lang_key == NULL) - lang_key_len = 0; + case PNG_TEXT_COMPRESSION_zTXt: + case PNG_ITXT_COMPRESSION_zTXt: + compression = new_key[++key_len] = 1; /* compressed */ + break; - else - lang_key_len = png_strlen(lang_key); + default: + png_error(png_ptr, "iTXt: invalid compression"); + } - if (text == NULL) - text_len = 0; + 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 - 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); + 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); - /* Make sure we include the compression flag, the compression byte, - * and the NULs after the key, lang, and lang_key parts - */ + png_text_compress_init(&comp, (png_const_bytep)text, strlen(text)); - png_write_chunk_header(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)); + if (compression != 0) + { + if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg); + } - /* 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)key, (png_size_t)(key_len + 1)); + else + { + if (comp.input_len > PNG_UINT_31_MAX-prefix_len) + png_error(png_ptr, "iTXt: uncompressed text too long"); - /* Set the compression flag */ - if (compression == PNG_ITXT_COMPRESSION_NONE || - compression == PNG_TEXT_COMPRESSION_NONE) - cbuf[0] = 0; + /* So the string will fit in a chunk: */ + comp.output_len = (png_uint_32)/*SAFE*/comp.input_len; + } - else /* compression == PNG_ITXT_COMPRESSION_zTXt */ - cbuf[0] = 1; + png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len); - /* Set the compression method */ - cbuf[1] = 0; + png_write_chunk_data(png_ptr, new_key, key_len); - png_write_chunk_data(png_ptr, cbuf, (png_size_t)2); + png_write_chunk_data(png_ptr, (png_const_bytep)lang, lang_len); - cbuf[0] = 0; - png_write_chunk_data(png_ptr, (lang ? (png_const_bytep)lang : cbuf), - (png_size_t)(lang_len + 1)); + png_write_chunk_data(png_ptr, (png_const_bytep)lang_key, lang_key_len); - png_write_chunk_data(png_ptr, (lang_key ? (png_const_bytep)lang_key : cbuf), - (png_size_t)(lang_key_len + 1)); + if (compression != 0) + png_write_compressed_data_out(png_ptr, &comp); - png_write_compressed_data_out(png_ptr, &comp, text_len); + else + png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.output_len); png_write_chunk_end(png_ptr); } @@ -1686,7 +1693,7 @@ png_write_iTXt(png_structp png_ptr, int compression, png_const_charp key, #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, +png_write_oFFs(png_structrp png_ptr, png_int_32 x_offset, png_int_32 y_offset, int unit_type) { png_byte buf[9]; @@ -1706,35 +1713,43 @@ png_write_oFFs(png_structp png_ptr, png_int_32 x_offset, png_int_32 y_offset, #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_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_size_t purpose_len, units_len, total_len; + 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_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); + 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 */ - purpose_len = strlen(purpose) + 1; png_debug1(3, "pCAL purpose length = %d", (int)purpose_len); - units_len = png_strlen(units) + (nparams == 0 ? 0 : 1); + 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 * png_sizeof(png_size_t))); + (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] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1); + 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]; @@ -1742,7 +1757,7 @@ png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, 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, (png_const_bytep)purpose, purpose_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; @@ -1763,7 +1778,7 @@ png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, #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_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width, png_const_charp height) { png_byte buf[64]; @@ -1771,8 +1786,8 @@ png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width, png_debug(1, "in png_write_sCAL_s"); - wlen = png_strlen(width); - hlen = png_strlen(height); + wlen = strlen(width); + hlen = strlen(height); total_len = wlen + hlen + 2; if (total_len > 64) @@ -1782,8 +1797,8 @@ png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width, } 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 */ + 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); @@ -1793,7 +1808,7 @@ png_write_sCAL_s(png_structp png_ptr, int unit, png_const_charp width, #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_write_pHYs(png_structrp png_ptr, png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit, int unit_type) { @@ -1817,7 +1832,7 @@ png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, * 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_write_tIME(png_structrp png_ptr, png_const_timep mod_time) { png_byte buf[7]; @@ -1844,7 +1859,7 @@ png_write_tIME(png_structp png_ptr, png_const_timep mod_time) /* Initializes the row writing capability of libpng */ void /* PRIVATE */ -png_write_start_row(png_structp png_ptr) +png_write_start_row(png_structrp png_ptr) { #ifdef PNG_WRITE_INTERLACING_SUPPORTED /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ @@ -1865,6 +1880,10 @@ png_write_start_row(png_structp png_ptr) png_alloc_size_t buf_size; int usr_pixel_depth; +#ifdef PNG_WRITE_FILTER_SUPPORTED + png_byte filters; +#endif + png_debug(1, "in png_write_start_row"); usr_pixel_depth = png_ptr->usr_channels * png_ptr->usr_bit_depth; @@ -1875,56 +1894,61 @@ png_write_start_row(png_structp png_ptr) 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 = png_voidcast(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); + filters = png_ptr->do_filter; - png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB; - } + if (png_ptr->height == 1) + filters &= 0xff & ~(PNG_FILTER_UP|PNG_FILTER_AVG|PNG_FILTER_PAETH); - /* 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)) + if (png_ptr->width == 1) + filters &= 0xff & ~(PNG_FILTER_SUB|PNG_FILTER_AVG|PNG_FILTER_PAETH); + + if (filters == 0) + filters = PNG_FILTER_NONE; + + png_ptr->do_filter = filters; + + if (((filters & (PNG_FILTER_SUB | PNG_FILTER_UP | PNG_FILTER_AVG | + PNG_FILTER_PAETH)) != 0) && png_ptr->try_row == NULL) { - /* Set up previous row buffer */ - png_ptr->prev_row = (png_bytep)png_calloc(png_ptr, buf_size); + int num_filters = 0; - if (png_ptr->do_filter & PNG_FILTER_UP) - { - png_ptr->up_row = (png_bytep)png_malloc(png_ptr, - png_ptr->rowbytes + 1); + png_ptr->try_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size)); - png_ptr->up_row[0] = PNG_FILTER_VALUE_UP; - } + if (filters & PNG_FILTER_SUB) + num_filters++; - if (png_ptr->do_filter & PNG_FILTER_AVG) - { - png_ptr->avg_row = (png_bytep)png_malloc(png_ptr, - png_ptr->rowbytes + 1); + if (filters & PNG_FILTER_UP) + num_filters++; - png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG; - } + if (filters & PNG_FILTER_AVG) + num_filters++; - if (png_ptr->do_filter & PNG_FILTER_PAETH) - { - png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr, - png_ptr->rowbytes + 1); + if (filters & PNG_FILTER_PAETH) + num_filters++; - png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; - } + if (num_filters > 1) + png_ptr->tst_row = png_voidcast(png_bytep, png_malloc(png_ptr, + buf_size)); } -#endif /* PNG_WRITE_FILTER_SUPPORTED */ + + /* We only need to keep the previous row if we are using one of the following + * filters. + */ + if ((filters & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) != 0) + png_ptr->prev_row = png_voidcast(png_bytep, + png_calloc(png_ptr, buf_size)); +#endif /* WRITE_FILTER */ #ifdef PNG_WRITE_INTERLACING_SUPPORTED /* If interlaced, we need to set up width and height of pass */ - if (png_ptr->interlaced) + if (png_ptr->interlaced != 0) { - if (!(png_ptr->transformations & PNG_INTERLACE)) + if ((png_ptr->transformations & PNG_INTERLACE) == 0) { png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - png_pass_ystart[0]) / png_pass_yinc[0]; @@ -1946,15 +1970,11 @@ png_write_start_row(png_structp png_ptr) 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) +png_write_finish_row(png_structrp png_ptr) { #ifdef PNG_WRITE_INTERLACING_SUPPORTED /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */ @@ -1972,8 +1992,6 @@ png_write_finish_row(png_structp png_ptr) static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2}; #endif - int ret; - png_debug(1, "in png_write_finish_row"); /* Next row */ @@ -1985,10 +2003,10 @@ png_write_finish_row(png_structp png_ptr) #ifdef PNG_WRITE_INTERLACING_SUPPORTED /* If interlaced, go to next pass */ - if (png_ptr->interlaced) + if (png_ptr->interlaced != 0) { png_ptr->row_number = 0; - if (png_ptr->transformations & PNG_INTERLACE) + if ((png_ptr->transformations & PNG_INTERLACE) != 0) { png_ptr->pass++; } @@ -2013,7 +2031,7 @@ png_write_finish_row(png_structp png_ptr) png_pass_ystart[png_ptr->pass]) / png_pass_yinc[png_ptr->pass]; - if (png_ptr->transformations & PNG_INTERLACE) + if ((png_ptr->transformations & PNG_INTERLACE) != 0) break; } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0); @@ -2024,7 +2042,7 @@ png_write_finish_row(png_structp png_ptr) if (png_ptr->pass < 7) { if (png_ptr->prev_row != NULL) - png_memset(png_ptr->prev_row, 0, + memset(png_ptr->prev_row, 0, (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels* png_ptr->usr_bit_depth, png_ptr->width)) + 1); @@ -2035,42 +2053,7 @@ png_write_finish_row(png_structp png_ptr) /* 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; + png_compress_IDAT(png_ptr, NULL, 0, Z_FINISH); } #ifdef PNG_WRITE_INTERLACING_SUPPORTED @@ -2104,7 +2087,7 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) { png_bytep sp; png_bytep dp; - int shift; + unsigned int shift; int d; int value; png_uint_32 i; @@ -2142,7 +2125,7 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) { png_bytep sp; png_bytep dp; - int shift; + unsigned int shift; int d; int value; png_uint_32 i; @@ -2179,7 +2162,7 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) { png_bytep sp; png_bytep dp; - int shift; + unsigned int shift; int d; int value; png_uint_32 i; @@ -2234,7 +2217,7 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) /* Move the pixel */ if (dp != sp) - png_memcpy(dp, sp, pixel_bytes); + memcpy(dp, sp, pixel_bytes); /* Next pixel */ dp += pixel_bytes; @@ -2254,25 +2237,171 @@ png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) } #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, +static void /* PRIVATE */ +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)) +#ifdef PNG_WRITE_FILTER_SUPPORTED +static png_size_t /* PRIVATE */ +png_setup_sub_row(png_structrp png_ptr, const png_uint_32 bpp, + const png_size_t row_bytes, const png_size_t lmins) +{ + png_bytep rp, dp, lp; + png_size_t i; + png_size_t sum = 0; + int v; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_SUB; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1; i < bpp; + i++, rp++, dp++) + { + v = *dp = *rp; + sum += (v < 128) ? v : 256 - v; + } + + for (lp = png_ptr->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; + } + + return (sum); +} + +static png_size_t /* PRIVATE */ +png_setup_up_row(png_structrp png_ptr, const png_size_t row_bytes, + const png_size_t lmins) +{ + png_bytep rp, dp, pp; + png_size_t i; + png_size_t sum = 0; + int v; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_UP; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, + pp = png_ptr->prev_row + 1; i < row_bytes; + i++, rp++, pp++, dp++) + { + 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; + } + + return (sum); +} + +static png_size_t /* PRIVATE */ +png_setup_avg_row(png_structrp png_ptr, const png_uint_32 bpp, + const png_size_t row_bytes, const png_size_t lmins) +{ + png_bytep rp, dp, pp, lp; + png_uint_32 i; + png_size_t sum = 0; + int v; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_AVG; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, + pp = png_ptr->prev_row + 1; i < bpp; i++) + { + v = *dp++ = (png_byte)(((int)*rp++ - ((int)*pp++ / 2)) & 0xff); + + sum += (v < 128) ? v : 256 - v; + } + + for (lp = png_ptr->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; + } + + return (sum); +} + +static png_size_t /* PRIVATE */ +png_setup_paeth_row(png_structrp png_ptr, const png_uint_32 bpp, + const png_size_t row_bytes, const png_size_t lmins) +{ + png_bytep rp, dp, pp, cp, lp; + png_size_t i; + png_size_t sum = 0; + int v; + + png_ptr->try_row[0] = PNG_FILTER_VALUE_PAETH; + + for (i = 0, rp = png_ptr->row_buf + 1, dp = png_ptr->try_row + 1, + pp = png_ptr->prev_row + 1; i < bpp; i++) + { + v = *dp++ = (png_byte)(((int)*rp++ - (int)*pp++) & 0xff); + + sum += (v < 128) ? v : 256 - v; + } + + for (lp = png_ptr->row_buf + 1, cp = png_ptr->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; + + 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; + } + + return (sum); +} +#endif /* WRITE_FILTER */ + void /* PRIVATE */ -png_write_find_filter(png_structp png_ptr, png_row_infop row_info) +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; +#ifndef PNG_WRITE_FILTER_SUPPORTED + png_write_filtered_row(png_ptr, png_ptr->row_buf, row_info->rowbytes+1); +#else png_byte filter_to_do = png_ptr->do_filter; + png_bytep row_buf; + png_bytep best_row; + png_uint_32 bpp; + png_size_t mins; png_size_t row_bytes = row_info->rowbytes; png_debug(1, "in png_write_find_filter"); @@ -2280,12 +2409,9 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) /* 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; + row_buf = png_ptr->row_buf; + mins = PNG_SIZE_MAX - 256/* so we can detect potential overflow of the + running sum */; /* The prediction method we use is to find which method provides the * smallest value when summing the absolute values of the distances @@ -2315,17 +2441,35 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) /* 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) + best_row = png_ptr->row_buf; + + + if ((filter_to_do & PNG_FILTER_NONE) != 0 && filter_to_do != PNG_FILTER_NONE) { png_bytep rp; - png_uint_32 sum = 0; + png_size_t sum = 0; png_size_t i; int v; - for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) + if (PNG_SIZE_MAX/128 <= row_bytes) + { + for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) + { + /* Check for overflow */ + if (sum > PNG_SIZE_MAX/128 - 256) + break; + + v = *rp; + sum += (v < 128) ? v : 256 - v; + } + } + else /* Overflow is not possible */ { - v = *rp; - sum += (v < 128) ? v : 256 - v; + for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++) + { + v = *rp; + sum += (v < 128) ? v : 256 - v; + } } mins = sum; @@ -2335,325 +2479,125 @@ png_write_find_filter(png_structp png_ptr, png_row_infop row_info) 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; + (void) png_setup_sub_row(png_ptr, bpp, row_bytes, mins); + best_row = png_ptr->try_row; } - else if (filter_to_do & PNG_FILTER_SUB) + else if ((filter_to_do & PNG_FILTER_SUB) != 0) { - png_bytep rp, dp, lp; - png_uint_32 sum = 0, lmins = mins; - png_size_t i; - int v; + png_size_t sum; + png_size_t lmins = mins; - 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; - } + sum = png_setup_sub_row(png_ptr, bpp, row_bytes, lmins); if (sum < mins) { mins = sum; - best_row = png_ptr->sub_row; + best_row = png_ptr->try_row; + if (png_ptr->tst_row != NULL) + { + png_ptr->try_row = png_ptr->tst_row; + png_ptr->tst_row = best_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; + (void) png_setup_up_row(png_ptr, row_bytes, mins); + best_row = png_ptr->try_row; } - else if (filter_to_do & PNG_FILTER_UP) + else if ((filter_to_do & PNG_FILTER_UP) != 0) { - png_bytep rp, dp, pp; - png_uint_32 sum = 0, lmins = mins; - png_size_t i; - int v; - - 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; + png_size_t sum; + png_size_t lmins = mins; - if (sum > lmins) /* We are already worse, don't continue. */ - break; - } + sum = png_setup_up_row(png_ptr, row_bytes, lmins); if (sum < mins) { mins = sum; - best_row = png_ptr->up_row; + best_row = png_ptr->try_row; + if (png_ptr->tst_row != NULL) + { + png_ptr->try_row = png_ptr->tst_row; + png_ptr->tst_row = best_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; + (void) png_setup_avg_row(png_ptr, bpp, row_bytes, mins); + best_row = png_ptr->try_row; } - else if (filter_to_do & PNG_FILTER_AVG) + else if ((filter_to_do & PNG_FILTER_AVG) != 0) { - png_bytep rp, dp, pp, lp; - png_uint_32 sum = 0, lmins = mins; - png_size_t i; - int v; - - 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); + png_size_t sum; + png_size_t lmins = mins; - 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; - } + sum= png_setup_avg_row(png_ptr, bpp, row_bytes, lmins); if (sum < mins) { mins = sum; - best_row = png_ptr->avg_row; + best_row = png_ptr->try_row; + if (png_ptr->tst_row != NULL) + { + png_ptr->try_row = png_ptr->tst_row; + png_ptr->tst_row = best_row; + } } } /* Paeth filter */ - if (filter_to_do == PNG_FILTER_PAETH) + if ((filter_to_do == PNG_FILTER_PAETH) != 0) { - 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; + (void) png_setup_paeth_row(png_ptr, bpp, row_bytes, mins); + best_row = png_ptr->try_row; } - else if (filter_to_do & PNG_FILTER_PAETH) + else if ((filter_to_do & PNG_FILTER_PAETH) != 0) { - png_bytep rp, dp, pp, cp, lp; - png_uint_32 sum = 0, lmins = mins; - png_size_t i; - int v; - - 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; + png_size_t sum; + png_size_t lmins = mins; - 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; - } + sum = png_setup_paeth_row(png_ptr, bpp, row_bytes, lmins); if (sum < mins) { - best_row = png_ptr->paeth_row; + best_row = png_ptr->try_row; + if (png_ptr->tst_row != NULL) + { + png_ptr->try_row = png_ptr->tst_row; + png_ptr->tst_row = best_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); + +#endif /* WRITE_FILTER */ } + /* 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/*includes filter byte*/) +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]); - /* Set up the zlib input buffer */ - - png_ptr->zstream.next_in = filtered_row; - png_ptr->zstream.avail_in = 0; - /* 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); + png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH); +#ifdef PNG_WRITE_FILTER_SUPPORTED /* Swap the current and previous rows */ if (png_ptr->prev_row != NULL) { @@ -2663,6 +2607,7 @@ png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row, png_ptr->prev_row = png_ptr->row_buf; png_ptr->row_buf = tptr; } +#endif /* WRITE_FILTER */ /* Finish row - updates counters and flushes zlib if last row */ png_write_finish_row(png_ptr); @@ -2675,6 +2620,6 @@ png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row, { png_write_flush(png_ptr); } -#endif +#endif /* WRITE_FLUSH */ } -#endif /* PNG_WRITE_SUPPORTED */ +#endif /* WRITE */ |