| Index: third_party/libpng/pngwutil.c
|
| diff --git a/third_party/libpng/pngwutil.c b/third_party/libpng/pngwutil.c
|
| new file mode 100644
|
| index 0000000000000000000000000000000000000000..494169051c2b8428415241f8f0ff4e66bd8cb535
|
| --- /dev/null
|
| +++ b/third_party/libpng/pngwutil.c
|
| @@ -0,0 +1,2625 @@
|
| +
|
| +/* pngwutil.c - utilities to write a PNG file
|
| + *
|
| + * Last changed in libpng 1.6.22 [(PENDING RELEASE)]
|
| + * Copyright (c) 1998-2002,2004,2006-2015 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) & 0xffU);
|
| + buf[1] = (png_byte)((i >> 16) & 0xffU);
|
| + buf[2] = (png_byte)((i >> 8) & 0xffU);
|
| + buf[3] = (png_byte)( i & 0xffU);
|
| +}
|
| +
|
| +/* 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) & 0xffU);
|
| + buf[1] = (png_byte)( i & 0xffU);
|
| +}
|
| +#endif
|
| +
|
| +/* Simple function to write the signature. If we have already written
|
| + * the magic bytes of the signature, or more likely, the PNG stream is
|
| + * being embedded into another stream and doesn't need its own signature,
|
| + * we should call png_set_sig_bytes() to tell libpng how many of the
|
| + * bytes have already been written.
|
| + */
|
| +void PNGAPI
|
| +png_write_sig(png_structrp png_ptr)
|
| +{
|
| + png_byte png_signature[8] = {137, 80, 78, 71, 13, 10, 26, 10};
|
| +
|
| +#ifdef PNG_IO_STATE_SUPPORTED
|
| + /* Inform the I/O callback that the signature is being written */
|
| + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_SIGNATURE;
|
| +#endif
|
| +
|
| + /* Write the rest of the 8 byte signature */
|
| + png_write_data(png_ptr, &png_signature[png_ptr->sig_bytes],
|
| + (png_size_t)(8 - png_ptr->sig_bytes));
|
| +
|
| + if (png_ptr->sig_bytes < 3)
|
| + png_ptr->mode |= PNG_HAVE_PNG_SIGNATURE;
|
| +}
|
| +
|
| +/* Write the start of a PNG chunk. The type is the chunk type.
|
| + * The total_length is the sum of the lengths of all the data you will be
|
| + * passing in png_write_chunk_data().
|
| + */
|
| +static void
|
| +png_write_chunk_header(png_structrp png_ptr, png_uint_32 chunk_name,
|
| + png_uint_32 length)
|
| +{
|
| + png_byte buf[8];
|
| +
|
| +#if defined(PNG_DEBUG) && (PNG_DEBUG > 0)
|
| + PNG_CSTRING_FROM_CHUNK(buf, chunk_name);
|
| + png_debug2(0, "Writing %s chunk, length = %lu", buf, (unsigned long)length);
|
| +#endif
|
| +
|
| + if (png_ptr == NULL)
|
| + return;
|
| +
|
| +#ifdef PNG_IO_STATE_SUPPORTED
|
| + /* Inform the I/O callback that the chunk header is being written.
|
| + * PNG_IO_CHUNK_HDR requires a single I/O call.
|
| + */
|
| + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_HDR;
|
| +#endif
|
| +
|
| + /* Write the length and the chunk name */
|
| + png_save_uint_32(buf, length);
|
| + png_save_uint_32(buf + 4, chunk_name);
|
| + png_write_data(png_ptr, buf, 8);
|
| +
|
| + /* Put the chunk name into png_ptr->chunk_name */
|
| + png_ptr->chunk_name = chunk_name;
|
| +
|
| + /* Reset the crc and run it over the chunk name */
|
| + png_reset_crc(png_ptr);
|
| +
|
| + png_calculate_crc(png_ptr, buf + 4, 4);
|
| +
|
| +#ifdef PNG_IO_STATE_SUPPORTED
|
| + /* Inform the I/O callback that chunk data will (possibly) be written.
|
| + * PNG_IO_CHUNK_DATA does NOT require a specific number of I/O calls.
|
| + */
|
| + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_DATA;
|
| +#endif
|
| +}
|
| +
|
| +void PNGAPI
|
| +png_write_chunk_start(png_structrp png_ptr, png_const_bytep chunk_string,
|
| + png_uint_32 length)
|
| +{
|
| + png_write_chunk_header(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), length);
|
| +}
|
| +
|
| +/* Write the data of a PNG chunk started with png_write_chunk_header().
|
| + * Note that multiple calls to this function are allowed, and that the
|
| + * sum of the lengths from these calls *must* add up to the total_length
|
| + * given to png_write_chunk_header().
|
| + */
|
| +void PNGAPI
|
| +png_write_chunk_data(png_structrp png_ptr, png_const_bytep data,
|
| + png_size_t length)
|
| +{
|
| + /* Write the data, and run the CRC over it */
|
| + if (png_ptr == NULL)
|
| + return;
|
| +
|
| + if (data != NULL && length > 0)
|
| + {
|
| + png_write_data(png_ptr, data, length);
|
| +
|
| + /* Update the CRC after writing the data,
|
| + * in case the user I/O routine alters it.
|
| + */
|
| + png_calculate_crc(png_ptr, data, length);
|
| + }
|
| +}
|
| +
|
| +/* Finish a chunk started with png_write_chunk_header(). */
|
| +void PNGAPI
|
| +png_write_chunk_end(png_structrp png_ptr)
|
| +{
|
| + png_byte buf[4];
|
| +
|
| + if (png_ptr == NULL) return;
|
| +
|
| +#ifdef PNG_IO_STATE_SUPPORTED
|
| + /* Inform the I/O callback that the chunk CRC is being written.
|
| + * PNG_IO_CHUNK_CRC requires a single I/O function call.
|
| + */
|
| + png_ptr->io_state = PNG_IO_WRITING | PNG_IO_CHUNK_CRC;
|
| +#endif
|
| +
|
| + /* Write the crc in a single operation */
|
| + png_save_uint_32(buf, png_ptr->crc);
|
| +
|
| + png_write_data(png_ptr, buf, (png_size_t)4);
|
| +}
|
| +
|
| +/* Write a PNG chunk all at once. The type is an array of ASCII characters
|
| + * representing the chunk name. The array must be at least 4 bytes in
|
| + * length, and does not need to be null terminated. To be safe, pass the
|
| + * pre-defined chunk names here, and if you need a new one, define it
|
| + * where the others are defined. The length is the length of the data.
|
| + * All the data must be present. If that is not possible, use the
|
| + * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end()
|
| + * functions instead.
|
| + */
|
| +static void
|
| +png_write_complete_chunk(png_structrp png_ptr, png_uint_32 chunk_name,
|
| + png_const_bytep data, png_size_t length)
|
| +{
|
| + if (png_ptr == NULL)
|
| + return;
|
| +
|
| + /* On 64-bit architectures 'length' may not fit in a png_uint_32. */
|
| + if (length > PNG_UINT_31_MAX)
|
| + png_error(png_ptr, "length exceeds PNG maximum");
|
| +
|
| + png_write_chunk_header(png_ptr, chunk_name, (png_uint_32)length);
|
| + png_write_chunk_data(png_ptr, data, length);
|
| + png_write_chunk_end(png_ptr);
|
| +}
|
| +
|
| +/* This is the API that calls the internal function above. */
|
| +void PNGAPI
|
| +png_write_chunk(png_structrp png_ptr, png_const_bytep chunk_string,
|
| + png_const_bytep data, png_size_t length)
|
| +{
|
| + png_write_complete_chunk(png_ptr, PNG_CHUNK_FROM_STRING(chunk_string), data,
|
| + length);
|
| +}
|
| +
|
| +/* This is used below to find the size of an image to pass to png_deflate_claim,
|
| + * so it only needs to be accurate if the size is less than 16384 bytes (the
|
| + * point at which a lower LZ window size can be used.)
|
| + */
|
| +static png_alloc_size_t
|
| +png_image_size(png_structrp png_ptr)
|
| +{
|
| + /* Only return sizes up to the maximum of a png_uint_32; do this by limiting
|
| + * the width and height used to 15 bits.
|
| + */
|
| + png_uint_32 h = png_ptr->height;
|
| +
|
| + if (png_ptr->rowbytes < 32768 && h < 32768)
|
| + {
|
| + if (png_ptr->interlaced != 0)
|
| + {
|
| + /* Interlacing makes the image larger because of the replication of
|
| + * both the filter byte and the padding to a byte boundary.
|
| + */
|
| + png_uint_32 w = png_ptr->width;
|
| + unsigned int pd = png_ptr->pixel_depth;
|
| + png_alloc_size_t cb_base;
|
| + int pass;
|
| +
|
| + for (cb_base=0, pass=0; pass<=6; ++pass)
|
| + {
|
| + png_uint_32 pw = PNG_PASS_COLS(w, pass);
|
| +
|
| + if (pw > 0)
|
| + cb_base += (PNG_ROWBYTES(pd, pw)+1) * PNG_PASS_ROWS(h, pass);
|
| + }
|
| +
|
| + return cb_base;
|
| + }
|
| +
|
| + else
|
| + return (png_ptr->rowbytes+1) * h;
|
| + }
|
| +
|
| + else
|
| + return 0xffffffffU;
|
| +}
|
| +
|
| +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
|
| + /* This is the code to hack the first two bytes of the deflate stream (the
|
| + * deflate header) to correct the windowBits value to match the actual data
|
| + * size. Note that the second argument is the *uncompressed* size but the
|
| + * first argument is the *compressed* data (and it must be deflate
|
| + * compressed.)
|
| + */
|
| +static void
|
| +optimize_cmf(png_bytep data, png_alloc_size_t data_size)
|
| +{
|
| + /* Optimize the CMF field in the zlib stream. The resultant zlib stream is
|
| + * still compliant to the stream specification.
|
| + */
|
| + if (data_size <= 16384) /* else windowBits must be 15 */
|
| + {
|
| + unsigned int z_cmf = data[0]; /* zlib compression method and flags */
|
| +
|
| + if ((z_cmf & 0x0f) == 8 && (z_cmf & 0xf0) <= 0x70)
|
| + {
|
| + unsigned int z_cinfo;
|
| + unsigned int half_z_window_size;
|
| +
|
| + z_cinfo = z_cmf >> 4;
|
| + half_z_window_size = 1U << (z_cinfo + 7);
|
| +
|
| + if (data_size <= half_z_window_size) /* else no change */
|
| + {
|
| + unsigned int tmp;
|
| +
|
| + do
|
| + {
|
| + half_z_window_size >>= 1;
|
| + --z_cinfo;
|
| + }
|
| + while (z_cinfo > 0 && data_size <= half_z_window_size);
|
| +
|
| + z_cmf = (z_cmf & 0x0f) | (z_cinfo << 4);
|
| +
|
| + data[0] = (png_byte)z_cmf;
|
| + tmp = data[1] & 0xe0;
|
| + tmp += 0x1f - ((z_cmf << 8) + tmp) % 0x1f;
|
| + data[1] = (png_byte)tmp;
|
| + }
|
| + }
|
| + }
|
| +}
|
| +#endif /* WRITE_OPTIMIZE_CMF */
|
| +
|
| +/* Initialize the compressor for the appropriate type of compression. */
|
| +static int
|
| +png_deflate_claim(png_structrp png_ptr, png_uint_32 owner,
|
| + png_alloc_size_t data_size)
|
| +{
|
| + if (png_ptr->zowner != 0)
|
| + {
|
| +#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);
|
| +
|
| + /* Attempt sane error recovery */
|
| + if (png_ptr->zowner == png_IDAT) /* don't steal from IDAT */
|
| + {
|
| + png_ptr->zstream.msg = PNGZ_MSG_CAST("in use by IDAT");
|
| + return Z_STREAM_ERROR;
|
| + }
|
| +
|
| + png_ptr->zowner = 0;
|
| +#else
|
| + png_error(png_ptr, msg);
|
| +#endif
|
| + }
|
| +
|
| + {
|
| + int level = png_ptr->zlib_level;
|
| + int method = png_ptr->zlib_method;
|
| + int windowBits = png_ptr->zlib_window_bits;
|
| + int memLevel = png_ptr->zlib_mem_level;
|
| + int strategy; /* set below */
|
| + int ret; /* zlib return code */
|
| +
|
| + if (owner == png_IDAT)
|
| + {
|
| + if ((png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY) != 0)
|
| + strategy = png_ptr->zlib_strategy;
|
| +
|
| + else if (png_ptr->do_filter != PNG_FILTER_NONE)
|
| + strategy = PNG_Z_DEFAULT_STRATEGY;
|
| +
|
| + else
|
| + strategy = PNG_Z_DEFAULT_NOFILTER_STRATEGY;
|
| + }
|
| +
|
| + else
|
| + {
|
| +#ifdef PNG_WRITE_CUSTOMIZE_ZTXT_COMPRESSION_SUPPORTED
|
| + level = png_ptr->zlib_text_level;
|
| + method = png_ptr->zlib_text_method;
|
| + windowBits = png_ptr->zlib_text_window_bits;
|
| + memLevel = png_ptr->zlib_text_mem_level;
|
| + strategy = png_ptr->zlib_text_strategy;
|
| +#else
|
| + /* If customization is not supported the values all come from the
|
| + * IDAT values except for the strategy, which is fixed to the
|
| + * default. (This is the pre-1.6.0 behavior too, although it was
|
| + * implemented in a very different way.)
|
| + */
|
| + strategy = Z_DEFAULT_STRATEGY;
|
| +#endif
|
| + }
|
| +
|
| + /* Adjust 'windowBits' down if larger than 'data_size'; to stop this
|
| + * happening just pass 32768 as the data_size parameter. Notice that zlib
|
| + * requires an extra 262 bytes in the window in addition to the data to be
|
| + * able to see the whole of the data, so if data_size+262 takes us to the
|
| + * next windowBits size we need to fix up the value later. (Because even
|
| + * though deflate needs the extra window, inflate does not!)
|
| + */
|
| + if (data_size <= 16384)
|
| + {
|
| + /* IMPLEMENTATION NOTE: this 'half_window_size' stuff is only here to
|
| + * work round a Microsoft Visual C misbehavior which, contrary to C-90,
|
| + * widens the result of the following shift to 64-bits if (and,
|
| + * apparently, only if) it is used in a test.
|
| + */
|
| + unsigned int half_window_size = 1U << (windowBits-1);
|
| +
|
| + while (data_size + 262 <= half_window_size)
|
| + {
|
| + half_window_size >>= 1;
|
| + --windowBits;
|
| + }
|
| + }
|
| +
|
| + /* Check against the previous initialized values, if any. */
|
| + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 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))
|
| + {
|
| + if (deflateEnd(&png_ptr->zstream) != Z_OK)
|
| + png_warning(png_ptr, "deflateEnd failed (ignored)");
|
| +
|
| + png_ptr->flags &= ~PNG_FLAG_ZSTREAM_INITIALIZED;
|
| + }
|
| +
|
| + /* For safety clear out the input and output pointers (currently zlib
|
| + * doesn't use them on Init, but it might in the future).
|
| + */
|
| + png_ptr->zstream.next_in = NULL;
|
| + png_ptr->zstream.avail_in = 0;
|
| + png_ptr->zstream.next_out = NULL;
|
| + png_ptr->zstream.avail_out = 0;
|
| +
|
| + /* Now initialize if required, setting the new parameters, otherwise just
|
| + * to a simple reset to the previous parameters.
|
| + */
|
| + if ((png_ptr->flags & PNG_FLAG_ZSTREAM_INITIALIZED) != 0)
|
| + ret = deflateReset(&png_ptr->zstream);
|
| +
|
| + else
|
| + {
|
| + ret = deflateInit2(&png_ptr->zstream, level, method, windowBits,
|
| + memLevel, strategy);
|
| +
|
| + if (ret == Z_OK)
|
| + png_ptr->flags |= PNG_FLAG_ZSTREAM_INITIALIZED;
|
| + }
|
| +
|
| + /* The return code is from either deflateReset or deflateInit2; they have
|
| + * pretty much the same set of error codes.
|
| + */
|
| + if (ret == Z_OK)
|
| + png_ptr->zowner = owner;
|
| +
|
| + else
|
| + png_zstream_error(png_ptr, ret);
|
| +
|
| + return ret;
|
| + }
|
| +}
|
| +
|
| +/* Clean up (or trim) a linked list of compression buffers. */
|
| +void /* PRIVATE */
|
| +png_free_buffer_list(png_structrp png_ptr, png_compression_bufferp *listp)
|
| +{
|
| + png_compression_bufferp list = *listp;
|
| +
|
| + if (list != NULL)
|
| + {
|
| + *listp = NULL;
|
| +
|
| + do
|
| + {
|
| + png_compression_bufferp next = list->next;
|
| +
|
| + png_free(png_ptr, list);
|
| + list = next;
|
| + }
|
| + while (list != NULL);
|
| + }
|
| +}
|
| +
|
| +#ifdef PNG_WRITE_COMPRESSED_TEXT_SUPPORTED
|
| +/* This pair of functions encapsulates the operation of (a) compressing a
|
| + * text string, and (b) issuing it later as a series of chunk data writes.
|
| + * The compression_state structure is shared context for these functions
|
| + * set up by the caller to allow access to the relevant local variables.
|
| + *
|
| + * compression_buffer (new in 1.6.0) is just a linked list of zbuffer_size
|
| + * temporary buffers. From 1.6.0 it is retained in png_struct so that it will
|
| + * be correctly freed in the event of a write error (previous implementations
|
| + * just leaked memory.)
|
| + */
|
| +typedef struct
|
| +{
|
| + png_const_bytep input; /* The uncompressed input data */
|
| + png_alloc_size_t input_len; /* Its length */
|
| + png_uint_32 output_len; /* Final compressed length */
|
| + png_byte output[1024]; /* First block of output */
|
| +} compression_state;
|
| +
|
| +static void
|
| +png_text_compress_init(compression_state *comp, png_const_bytep input,
|
| + png_alloc_size_t input_len)
|
| +{
|
| + comp->input = input;
|
| + comp->input_len = input_len;
|
| + comp->output_len = 0;
|
| +}
|
| +
|
| +/* Compress the data in the compression state input */
|
| +static int
|
| +png_text_compress(png_structrp png_ptr, png_uint_32 chunk_name,
|
| + compression_state *comp, png_uint_32 prefix_len)
|
| +{
|
| + int ret;
|
| +
|
| + /* To find the length of the output it is necessary to first compress the
|
| + * input. The result is buffered rather than using the two-pass algorithm
|
| + * that is used on the inflate side; deflate is assumed to be slower and a
|
| + * PNG writer is assumed to have more memory available than a PNG reader.
|
| + *
|
| + * IMPLEMENTATION NOTE: the zlib API deflateBound() can be used to find an
|
| + * upper limit on the output size, but it is always bigger than the input
|
| + * size so it is likely to be more efficient to use this linked-list
|
| + * approach.
|
| + */
|
| + ret = png_deflate_claim(png_ptr, chunk_name, comp->input_len);
|
| +
|
| + if (ret != Z_OK)
|
| + return ret;
|
| +
|
| + /* Set up the compression buffers, we need a loop here to avoid overflowing a
|
| + * uInt. Use ZLIB_IO_MAX to limit the input. The output is always limited
|
| + * by the output buffer size, so there is no need to check that. Since this
|
| + * is ANSI-C we know that an 'int', hence a uInt, is always at least 16 bits
|
| + * in size.
|
| + */
|
| + {
|
| + png_compression_bufferp *end = &png_ptr->zbuffer_list;
|
| + png_alloc_size_t input_len = comp->input_len; /* may be zero! */
|
| + png_uint_32 output_len;
|
| +
|
| + /* zlib updates these for us: */
|
| + png_ptr->zstream.next_in = PNGZ_INPUT_CAST(comp->input);
|
| + png_ptr->zstream.avail_in = 0; /* Set below */
|
| + png_ptr->zstream.next_out = comp->output;
|
| + png_ptr->zstream.avail_out = (sizeof comp->output);
|
| +
|
| + output_len = png_ptr->zstream.avail_out;
|
| +
|
| + do
|
| + {
|
| + uInt avail_in = ZLIB_IO_MAX;
|
| +
|
| + if (avail_in > input_len)
|
| + avail_in = (uInt)input_len;
|
| +
|
| + input_len -= avail_in;
|
| +
|
| + png_ptr->zstream.avail_in = avail_in;
|
| +
|
| + if (png_ptr->zstream.avail_out == 0)
|
| + {
|
| + png_compression_buffer *next;
|
| +
|
| + /* Chunk data is limited to 2^31 bytes in length, so the prefix
|
| + * length must be counted here.
|
| + */
|
| + if (output_len + prefix_len > PNG_UINT_31_MAX)
|
| + {
|
| + ret = Z_MEM_ERROR;
|
| + break;
|
| + }
|
| +
|
| + /* Need a new (malloc'ed) buffer, but there may be one present
|
| + * already.
|
| + */
|
| + next = *end;
|
| + if (next == NULL)
|
| + {
|
| + next = png_voidcast(png_compression_bufferp, png_malloc_base
|
| + (png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
|
| +
|
| + if (next == NULL)
|
| + {
|
| + ret = Z_MEM_ERROR;
|
| + break;
|
| + }
|
| +
|
| + /* Link in this buffer (so that it will be freed later) */
|
| + next->next = NULL;
|
| + *end = next;
|
| + }
|
| +
|
| + png_ptr->zstream.next_out = next->output;
|
| + png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
|
| + output_len += png_ptr->zstream.avail_out;
|
| +
|
| + /* Move 'end' to the next buffer pointer. */
|
| + end = &next->next;
|
| + }
|
| +
|
| + /* Compress the data */
|
| + ret = deflate(&png_ptr->zstream,
|
| + input_len > 0 ? Z_NO_FLUSH : Z_FINISH);
|
| +
|
| + /* Claw back input data that was not consumed (because avail_in is
|
| + * reset above every time round the loop).
|
| + */
|
| + input_len += png_ptr->zstream.avail_in;
|
| + png_ptr->zstream.avail_in = 0; /* safety */
|
| + }
|
| + while (ret == Z_OK);
|
| +
|
| + /* There may be some space left in the last output buffer. This needs to
|
| + * be subtracted from output_len.
|
| + */
|
| + output_len -= png_ptr->zstream.avail_out;
|
| + png_ptr->zstream.avail_out = 0; /* safety */
|
| + comp->output_len = output_len;
|
| +
|
| + /* Now double check the output length, put in a custom message if it is
|
| + * too long. Otherwise ensure the z_stream::msg pointer is set to
|
| + * something.
|
| + */
|
| + if (output_len + prefix_len >= PNG_UINT_31_MAX)
|
| + {
|
| + png_ptr->zstream.msg = PNGZ_MSG_CAST("compressed data too long");
|
| + ret = Z_MEM_ERROR;
|
| + }
|
| +
|
| + else
|
| + png_zstream_error(png_ptr, ret);
|
| +
|
| + /* Reset zlib for another zTXt/iTXt or image data */
|
| + png_ptr->zowner = 0;
|
| +
|
| + /* The only success case is Z_STREAM_END, input_len must be 0; if not this
|
| + * is an internal error.
|
| + */
|
| + if (ret == Z_STREAM_END && input_len == 0)
|
| + {
|
| +#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
|
| + return ret;
|
| + }
|
| +}
|
| +
|
| +/* Ship the compressed text out via chunk writes */
|
| +static void
|
| +png_write_compressed_data_out(png_structrp png_ptr, compression_state *comp)
|
| +{
|
| + png_uint_32 output_len = comp->output_len;
|
| + png_const_bytep output = comp->output;
|
| + png_uint_32 avail = (sizeof comp->output);
|
| + png_compression_buffer *next = png_ptr->zbuffer_list;
|
| +
|
| + for (;;)
|
| + {
|
| + if (avail > output_len)
|
| + avail = output_len;
|
| +
|
| + png_write_chunk_data(png_ptr, output, avail);
|
| +
|
| + output_len -= avail;
|
| +
|
| + if (output_len == 0 || next == NULL)
|
| + break;
|
| +
|
| + avail = png_ptr->zbuffer_size;
|
| + output = next->output;
|
| + next = next->next;
|
| + }
|
| +
|
| + /* This is an internal error; 'next' must have been NULL! */
|
| + if (output_len > 0)
|
| + png_error(png_ptr, "error writing ancillary chunked compressed data");
|
| +}
|
| +#endif /* 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_structrp png_ptr, png_uint_32 width, png_uint_32 height,
|
| + int bit_depth, int color_type, int compression_type, int filter_type,
|
| + int interlace_type)
|
| +{
|
| + png_byte buf[13]; /* Buffer to store the IHDR info */
|
| +
|
| + png_debug(1, "in png_write_IHDR");
|
| +
|
| + /* Check that we have valid input data from the application info */
|
| + switch (color_type)
|
| + {
|
| + case PNG_COLOR_TYPE_GRAY:
|
| + switch (bit_depth)
|
| + {
|
| + case 1:
|
| + case 2:
|
| + case 4:
|
| + case 8:
|
| +#ifdef PNG_WRITE_16BIT_SUPPORTED
|
| + case 16:
|
| +#endif
|
| + png_ptr->channels = 1; break;
|
| +
|
| + default:
|
| + png_error(png_ptr,
|
| + "Invalid bit depth for grayscale image");
|
| + }
|
| + break;
|
| +
|
| + case PNG_COLOR_TYPE_RGB:
|
| +#ifdef PNG_WRITE_16BIT_SUPPORTED
|
| + if (bit_depth != 8 && bit_depth != 16)
|
| +#else
|
| + if (bit_depth != 8)
|
| +#endif
|
| + png_error(png_ptr, "Invalid bit depth for RGB image");
|
| +
|
| + png_ptr->channels = 3;
|
| + break;
|
| +
|
| + case PNG_COLOR_TYPE_PALETTE:
|
| + switch (bit_depth)
|
| + {
|
| + case 1:
|
| + case 2:
|
| + case 4:
|
| + case 8:
|
| + png_ptr->channels = 1;
|
| + break;
|
| +
|
| + default:
|
| + png_error(png_ptr, "Invalid bit depth for paletted image");
|
| + }
|
| + break;
|
| +
|
| + case PNG_COLOR_TYPE_GRAY_ALPHA:
|
| + if (bit_depth != 8 && bit_depth != 16)
|
| + png_error(png_ptr, "Invalid bit depth for grayscale+alpha image");
|
| +
|
| + png_ptr->channels = 2;
|
| + break;
|
| +
|
| + case PNG_COLOR_TYPE_RGB_ALPHA:
|
| +#ifdef PNG_WRITE_16BIT_SUPPORTED
|
| + if (bit_depth != 8 && bit_depth != 16)
|
| +#else
|
| + if (bit_depth != 8)
|
| +#endif
|
| + png_error(png_ptr, "Invalid bit depth for RGBA image");
|
| +
|
| + png_ptr->channels = 4;
|
| + break;
|
| +
|
| + default:
|
| + png_error(png_ptr, "Invalid image color type specified");
|
| + }
|
| +
|
| + if (compression_type != PNG_COMPRESSION_TYPE_BASE)
|
| + {
|
| + png_warning(png_ptr, "Invalid compression type specified");
|
| + compression_type = PNG_COMPRESSION_TYPE_BASE;
|
| + }
|
| +
|
| + /* Write filter_method 64 (intrapixel differencing) only if
|
| + * 1. Libpng was compiled with PNG_MNG_FEATURES_SUPPORTED and
|
| + * 2. Libpng did not write a PNG signature (this filter_method is only
|
| + * used in PNG datastreams that are embedded in MNG datastreams) and
|
| + * 3. The application called png_permit_mng_features with a mask that
|
| + * included PNG_FLAG_MNG_FILTER_64 and
|
| + * 4. The filter_method is 64 and
|
| + * 5. The color_type is RGB or RGBA
|
| + */
|
| + if (
|
| +#ifdef PNG_MNG_FEATURES_SUPPORTED
|
| + !((png_ptr->mng_features_permitted & PNG_FLAG_MNG_FILTER_64) != 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)) &&
|
| +#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 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;
|
| +#ifdef PNG_MNG_FEATURES_SUPPORTED
|
| + png_ptr->filter_type = (png_byte)filter_type;
|
| +#endif
|
| + png_ptr->compression_type = (png_byte)compression_type;
|
| + png_ptr->width = width;
|
| + png_ptr->height = height;
|
| +
|
| + png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels);
|
| + png_ptr->rowbytes = PNG_ROWBYTES(png_ptr->pixel_depth, width);
|
| + /* Set the usr info, so any transformations can modify it */
|
| + png_ptr->usr_width = png_ptr->width;
|
| + png_ptr->usr_bit_depth = png_ptr->bit_depth;
|
| + png_ptr->usr_channels = png_ptr->channels;
|
| +
|
| + /* Pack the header information into the buffer */
|
| + png_save_uint_32(buf, width);
|
| + png_save_uint_32(buf + 4, height);
|
| + buf[8] = (png_byte)bit_depth;
|
| + buf[9] = (png_byte)color_type;
|
| + buf[10] = (png_byte)compression_type;
|
| + buf[11] = (png_byte)filter_type;
|
| + buf[12] = (png_byte)interlace_type;
|
| +
|
| + /* Write the chunk */
|
| + png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);
|
| +
|
| + if ((png_ptr->do_filter) == PNG_NO_FILTERS)
|
| + {
|
| + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
|
| + png_ptr->bit_depth < 8)
|
| + png_ptr->do_filter = PNG_FILTER_NONE;
|
| +
|
| + else
|
| + png_ptr->do_filter = PNG_ALL_FILTERS;
|
| + }
|
| +
|
| + png_ptr->mode = PNG_HAVE_IHDR; /* not READY_FOR_ZTXT */
|
| +}
|
| +
|
| +/* Write the palette. We are careful not to trust png_color to be in the
|
| + * correct order for PNG, so people can redefine it to any convenient
|
| + * structure.
|
| + */
|
| +void /* PRIVATE */
|
| +png_write_PLTE(png_structrp png_ptr, png_const_colorp palette,
|
| + png_uint_32 num_pal)
|
| +{
|
| + png_uint_32 max_palette_length, i;
|
| + png_const_colorp pal_ptr;
|
| + png_byte buf[3];
|
| +
|
| + png_debug(1, "in png_write_PLTE");
|
| +
|
| + max_palette_length = (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) ?
|
| + (1 << png_ptr->bit_depth) : PNG_MAX_PALETTE_LENGTH;
|
| +
|
| + if ((
|
| +#ifdef PNG_MNG_FEATURES_SUPPORTED
|
| + (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0 &&
|
| +#endif
|
| + num_pal == 0) || num_pal > max_palette_length)
|
| + {
|
| + 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) == 0)
|
| + {
|
| + png_warning(png_ptr,
|
| + "Ignoring request to write a PLTE chunk in grayscale PNG");
|
| +
|
| + return;
|
| + }
|
| +
|
| + png_ptr->num_palette = (png_uint_16)num_pal;
|
| + png_debug1(3, "num_palette = %d", png_ptr->num_palette);
|
| +
|
| + png_write_chunk_header(png_ptr, png_PLTE, (png_uint_32)(num_pal * 3));
|
| +#ifdef PNG_POINTER_INDEXING_SUPPORTED
|
| +
|
| + for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++)
|
| + {
|
| + buf[0] = pal_ptr->red;
|
| + buf[1] = pal_ptr->green;
|
| + buf[2] = pal_ptr->blue;
|
| + png_write_chunk_data(png_ptr, buf, (png_size_t)3);
|
| + }
|
| +
|
| +#else
|
| + /* This is a little slower but some buggy compilers need to do this
|
| + * instead
|
| + */
|
| + pal_ptr=palette;
|
| +
|
| + for (i = 0; i < num_pal; i++)
|
| + {
|
| + buf[0] = pal_ptr[i].red;
|
| + buf[1] = pal_ptr[i].green;
|
| + buf[2] = pal_ptr[i].blue;
|
| + png_write_chunk_data(png_ptr, buf, (png_size_t)3);
|
| + }
|
| +
|
| +#endif
|
| + png_write_chunk_end(png_ptr);
|
| + png_ptr->mode |= PNG_HAVE_PLTE;
|
| +}
|
| +
|
| +/* This is similar to png_text_compress, above, except that it does not require
|
| + * all of the data at once and, instead of buffering the compressed result,
|
| + * writes it as IDAT chunks. Unlike png_text_compress it *can* png_error out
|
| + * because it calls the write interface. As a result it does its own error
|
| + * reporting and does not return an error code. In the event of error it will
|
| + * just call png_error. The input data length may exceed 32-bits. The 'flush'
|
| + * parameter is exactly the same as that to deflate, with the following
|
| + * meanings:
|
| + *
|
| + * Z_NO_FLUSH: normal incremental output of compressed data
|
| + * Z_SYNC_FLUSH: do a SYNC_FLUSH, used by png_write_flush
|
| + * Z_FINISH: this is the end of the input, do a Z_FINISH and clean up
|
| + *
|
| + * The routine manages the acquire and release of the png_ptr->zstream by
|
| + * checking and (at the end) clearing png_ptr->zowner; it does some sanity
|
| + * checks on the 'mode' flags while doing this.
|
| + */
|
| +void /* PRIVATE */
|
| +png_compress_IDAT(png_structrp png_ptr, png_const_bytep input,
|
| + png_alloc_size_t input_len, int flush)
|
| +{
|
| + if (png_ptr->zowner != png_IDAT)
|
| + {
|
| + /* First time. Ensure we have a temporary buffer for compression and
|
| + * trim the buffer list if it has more than one entry to free memory.
|
| + * If 'WRITE_COMPRESSED_TEXT' is not set the list will never have been
|
| + * created at this point, but the check here is quick and safe.
|
| + */
|
| + if (png_ptr->zbuffer_list == NULL)
|
| + {
|
| + png_ptr->zbuffer_list = png_voidcast(png_compression_bufferp,
|
| + png_malloc(png_ptr, PNG_COMPRESSION_BUFFER_SIZE(png_ptr)));
|
| + png_ptr->zbuffer_list->next = NULL;
|
| + }
|
| +
|
| + else
|
| + png_free_buffer_list(png_ptr, &png_ptr->zbuffer_list->next);
|
| +
|
| + /* It is a terminal error if we can't claim the zstream. */
|
| + if (png_deflate_claim(png_ptr, png_IDAT, png_image_size(png_ptr)) != Z_OK)
|
| + png_error(png_ptr, png_ptr->zstream.msg);
|
| +
|
| + /* The output state is maintained in png_ptr->zstream, so it must be
|
| + * initialized here after the claim.
|
| + */
|
| + png_ptr->zstream.next_out = png_ptr->zbuffer_list->output;
|
| + png_ptr->zstream.avail_out = png_ptr->zbuffer_size;
|
| + }
|
| +
|
| + /* Now loop reading and writing until all the input is consumed or an error
|
| + * terminates the operation. The _out values are maintained across calls to
|
| + * this function, but the input must be reset each time.
|
| + */
|
| + png_ptr->zstream.next_in = PNGZ_INPUT_CAST(input);
|
| + png_ptr->zstream.avail_in = 0; /* set below */
|
| + for (;;)
|
| + {
|
| + int ret;
|
| +
|
| + /* INPUT: from the row data */
|
| + uInt avail = ZLIB_IO_MAX;
|
| +
|
| + if (avail > input_len)
|
| + avail = (uInt)input_len; /* safe because of the check */
|
| +
|
| + png_ptr->zstream.avail_in = avail;
|
| + input_len -= avail;
|
| +
|
| + ret = deflate(&png_ptr->zstream, input_len > 0 ? Z_NO_FLUSH : flush);
|
| +
|
| + /* Include as-yet unconsumed input */
|
| + input_len += png_ptr->zstream.avail_in;
|
| + png_ptr->zstream.avail_in = 0;
|
| +
|
| + /* OUTPUT: write complete IDAT chunks when avail_out drops to zero. Note
|
| + * that these two zstream fields are preserved across the calls, therefore
|
| + * there is no need to set these up on entry to the loop.
|
| + */
|
| + if (png_ptr->zstream.avail_out == 0)
|
| + {
|
| + png_bytep data = png_ptr->zbuffer_list->output;
|
| + uInt size = png_ptr->zbuffer_size;
|
| +
|
| + /* Write an IDAT containing the data then reset the buffer. The
|
| + * first IDAT may need deflate header optimization.
|
| + */
|
| +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
|
| + if ((png_ptr->mode & PNG_HAVE_IDAT) == 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! */
|
| + {
|
| + /* If all the input has been consumed then just return. If Z_FINISH
|
| + * was used as the flush parameter something has gone wrong if we get
|
| + * here.
|
| + */
|
| + if (input_len == 0)
|
| + {
|
| + if (flush == Z_FINISH)
|
| + png_error(png_ptr, "Z_OK on Z_FINISH with output space");
|
| +
|
| + return;
|
| + }
|
| + }
|
| +
|
| + else if (ret == Z_STREAM_END && flush == Z_FINISH)
|
| + {
|
| + /* This is the end of the IDAT data; any pending output must be
|
| + * flushed. For small PNG files we may still be at the beginning.
|
| + */
|
| + png_bytep data = png_ptr->zbuffer_list->output;
|
| + uInt size = png_ptr->zbuffer_size - png_ptr->zstream.avail_out;
|
| +
|
| +#ifdef PNG_WRITE_OPTIMIZE_CMF_SUPPORTED
|
| + if ((png_ptr->mode & PNG_HAVE_IDAT) == 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->zstream.avail_out = 0;
|
| + png_ptr->zstream.next_out = NULL;
|
| + png_ptr->mode |= PNG_HAVE_IDAT | PNG_AFTER_IDAT;
|
| +
|
| + png_ptr->zowner = 0; /* Release the stream */
|
| + return;
|
| + }
|
| +
|
| + else
|
| + {
|
| + /* This is an error condition. */
|
| + png_zstream_error(png_ptr, ret);
|
| + png_error(png_ptr, png_ptr->zstream.msg);
|
| + }
|
| + }
|
| +}
|
| +
|
| +/* Write an IEND chunk */
|
| +void /* PRIVATE */
|
| +png_write_IEND(png_structrp png_ptr)
|
| +{
|
| + png_debug(1, "in png_write_IEND");
|
| +
|
| + png_write_complete_chunk(png_ptr, png_IEND, NULL, (png_size_t)0);
|
| + png_ptr->mode |= PNG_HAVE_IEND;
|
| +}
|
| +
|
| +#ifdef PNG_WRITE_gAMA_SUPPORTED
|
| +/* Write a gAMA chunk */
|
| +void /* PRIVATE */
|
| +png_write_gAMA_fixed(png_structrp png_ptr, png_fixed_point file_gamma)
|
| +{
|
| + png_byte buf[4];
|
| +
|
| + png_debug(1, "in png_write_gAMA");
|
| +
|
| + /* file_gamma is saved in 1/100,000ths */
|
| + png_save_uint_32(buf, (png_uint_32)file_gamma);
|
| + png_write_complete_chunk(png_ptr, png_gAMA, buf, (png_size_t)4);
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_sRGB_SUPPORTED
|
| +/* Write a sRGB chunk */
|
| +void /* PRIVATE */
|
| +png_write_sRGB(png_structrp png_ptr, int srgb_intent)
|
| +{
|
| + png_byte buf[1];
|
| +
|
| + png_debug(1, "in png_write_sRGB");
|
| +
|
| + if (srgb_intent >= PNG_sRGB_INTENT_LAST)
|
| + png_warning(png_ptr,
|
| + "Invalid sRGB rendering intent specified");
|
| +
|
| + buf[0]=(png_byte)srgb_intent;
|
| + png_write_complete_chunk(png_ptr, png_sRGB, buf, (png_size_t)1);
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_iCCP_SUPPORTED
|
| +/* Write an iCCP chunk */
|
| +void /* PRIVATE */
|
| +png_write_iCCP(png_structrp png_ptr, png_const_charp name,
|
| + png_const_bytep profile)
|
| +{
|
| + png_uint_32 name_len;
|
| + png_uint_32 profile_len;
|
| + png_byte new_name[81]; /* 1 byte for the compression byte */
|
| + compression_state comp;
|
| + png_uint_32 temp;
|
| +
|
| + png_debug(1, "in png_write_iCCP");
|
| +
|
| + /* These are all internal problems: the profile should have been checked
|
| + * before when it was stored.
|
| + */
|
| + if (profile == NULL)
|
| + png_error(png_ptr, "No profile for iCCP chunk"); /* internal error */
|
| +
|
| + profile_len = png_get_uint_32(profile);
|
| +
|
| + if (profile_len < 132)
|
| + png_error(png_ptr, "ICC profile too short");
|
| +
|
| + temp = (png_uint_32) (*(profile+8));
|
| + if (temp > 3 && (profile_len & 0x03))
|
| + png_error(png_ptr, "ICC profile length invalid (not a multiple of 4)");
|
| +
|
| + {
|
| + png_uint_32 embedded_profile_len = png_get_uint_32(profile);
|
| +
|
| + if (profile_len != embedded_profile_len)
|
| + png_error(png_ptr, "Profile length does not match profile");
|
| + }
|
| +
|
| + name_len = png_check_keyword(png_ptr, name, new_name);
|
| +
|
| + if (name_len == 0)
|
| + png_error(png_ptr, "iCCP: invalid keyword");
|
| +
|
| + new_name[++name_len] = PNG_COMPRESSION_TYPE_BASE;
|
| +
|
| + /* Make sure we include the NULL after the name and the compression type */
|
| + ++name_len;
|
| +
|
| + png_text_compress_init(&comp, profile, profile_len);
|
| +
|
| + /* Allow for keyword terminator and compression byte */
|
| + if (png_text_compress(png_ptr, png_iCCP, &comp, name_len) != Z_OK)
|
| + png_error(png_ptr, png_ptr->zstream.msg);
|
| +
|
| + png_write_chunk_header(png_ptr, png_iCCP, name_len + comp.output_len);
|
| +
|
| + png_write_chunk_data(png_ptr, new_name, name_len);
|
| +
|
| + png_write_compressed_data_out(png_ptr, &comp);
|
| +
|
| + png_write_chunk_end(png_ptr);
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_sPLT_SUPPORTED
|
| +/* Write a sPLT chunk */
|
| +void /* PRIVATE */
|
| +png_write_sPLT(png_structrp png_ptr, png_const_sPLT_tp spalette)
|
| +{
|
| + png_uint_32 name_len;
|
| + png_byte new_name[80];
|
| + png_byte entrybuf[10];
|
| + png_size_t entry_size = (spalette->depth == 8 ? 6 : 10);
|
| + png_size_t palette_size = entry_size * spalette->nentries;
|
| + png_sPLT_entryp ep;
|
| +#ifndef PNG_POINTER_INDEXING_SUPPORTED
|
| + int i;
|
| +#endif
|
| +
|
| + png_debug(1, "in png_write_sPLT");
|
| +
|
| + name_len = png_check_keyword(png_ptr, spalette->name, new_name);
|
| +
|
| + if (name_len == 0)
|
| + png_error(png_ptr, "sPLT: invalid keyword");
|
| +
|
| + /* Make sure we include the NULL after the name */
|
| + png_write_chunk_header(png_ptr, png_sPLT,
|
| + (png_uint_32)(name_len + 2 + palette_size));
|
| +
|
| + png_write_chunk_data(png_ptr, (png_bytep)new_name,
|
| + (png_size_t)(name_len + 1));
|
| +
|
| + png_write_chunk_data(png_ptr, &spalette->depth, (png_size_t)1);
|
| +
|
| + /* Loop through each palette entry, writing appropriately */
|
| +#ifdef PNG_POINTER_INDEXING_SUPPORTED
|
| + for (ep = spalette->entries; ep<spalette->entries + spalette->nentries; ep++)
|
| + {
|
| + if (spalette->depth == 8)
|
| + {
|
| + entrybuf[0] = (png_byte)ep->red;
|
| + entrybuf[1] = (png_byte)ep->green;
|
| + entrybuf[2] = (png_byte)ep->blue;
|
| + entrybuf[3] = (png_byte)ep->alpha;
|
| + png_save_uint_16(entrybuf + 4, ep->frequency);
|
| + }
|
| +
|
| + else
|
| + {
|
| + png_save_uint_16(entrybuf + 0, ep->red);
|
| + png_save_uint_16(entrybuf + 2, ep->green);
|
| + png_save_uint_16(entrybuf + 4, ep->blue);
|
| + png_save_uint_16(entrybuf + 6, ep->alpha);
|
| + png_save_uint_16(entrybuf + 8, ep->frequency);
|
| + }
|
| +
|
| + png_write_chunk_data(png_ptr, entrybuf, entry_size);
|
| + }
|
| +#else
|
| + ep=spalette->entries;
|
| + for (i = 0; i>spalette->nentries; i++)
|
| + {
|
| + if (spalette->depth == 8)
|
| + {
|
| + entrybuf[0] = (png_byte)ep[i].red;
|
| + entrybuf[1] = (png_byte)ep[i].green;
|
| + entrybuf[2] = (png_byte)ep[i].blue;
|
| + entrybuf[3] = (png_byte)ep[i].alpha;
|
| + png_save_uint_16(entrybuf + 4, ep[i].frequency);
|
| + }
|
| +
|
| + else
|
| + {
|
| + png_save_uint_16(entrybuf + 0, ep[i].red);
|
| + png_save_uint_16(entrybuf + 2, ep[i].green);
|
| + png_save_uint_16(entrybuf + 4, ep[i].blue);
|
| + png_save_uint_16(entrybuf + 6, ep[i].alpha);
|
| + png_save_uint_16(entrybuf + 8, ep[i].frequency);
|
| + }
|
| +
|
| + png_write_chunk_data(png_ptr, entrybuf, entry_size);
|
| + }
|
| +#endif
|
| +
|
| + png_write_chunk_end(png_ptr);
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_sBIT_SUPPORTED
|
| +/* Write the sBIT chunk */
|
| +void /* PRIVATE */
|
| +png_write_sBIT(png_structrp png_ptr, png_const_color_8p sbit, int color_type)
|
| +{
|
| + png_byte buf[4];
|
| + png_size_t size;
|
| +
|
| + png_debug(1, "in png_write_sBIT");
|
| +
|
| + /* Make sure we don't depend upon the order of PNG_COLOR_8 */
|
| + if ((color_type & PNG_COLOR_MASK_COLOR) != 0)
|
| + {
|
| + 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) != 0)
|
| + {
|
| + if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth)
|
| + {
|
| + png_warning(png_ptr, "Invalid sBIT depth specified");
|
| + return;
|
| + }
|
| +
|
| + buf[size++] = sbit->alpha;
|
| + }
|
| +
|
| + png_write_complete_chunk(png_ptr, png_sBIT, buf, size);
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_cHRM_SUPPORTED
|
| +/* Write the cHRM chunk */
|
| +void /* PRIVATE */
|
| +png_write_cHRM_fixed(png_structrp png_ptr, const png_xy *xy)
|
| +{
|
| + png_byte buf[32];
|
| +
|
| + png_debug(1, "in png_write_cHRM");
|
| +
|
| + /* Each value is saved in 1/100,000ths */
|
| + png_save_int_32(buf, xy->whitex);
|
| + png_save_int_32(buf + 4, xy->whitey);
|
| +
|
| + png_save_int_32(buf + 8, xy->redx);
|
| + png_save_int_32(buf + 12, xy->redy);
|
| +
|
| + png_save_int_32(buf + 16, xy->greenx);
|
| + png_save_int_32(buf + 20, xy->greeny);
|
| +
|
| + png_save_int_32(buf + 24, xy->bluex);
|
| + png_save_int_32(buf + 28, xy->bluey);
|
| +
|
| + png_write_complete_chunk(png_ptr, png_cHRM, buf, 32);
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_tRNS_SUPPORTED
|
| +/* Write the tRNS chunk */
|
| +void /* PRIVATE */
|
| +png_write_tRNS(png_structrp png_ptr, png_const_bytep trans_alpha,
|
| + png_const_color_16p tran, int num_trans, int color_type)
|
| +{
|
| + png_byte buf[6];
|
| +
|
| + png_debug(1, "in png_write_tRNS");
|
| +
|
| + if (color_type == PNG_COLOR_TYPE_PALETTE)
|
| + {
|
| + if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette)
|
| + {
|
| + png_app_warning(png_ptr,
|
| + "Invalid number of transparent colors specified");
|
| + return;
|
| + }
|
| +
|
| + /* Write the chunk out as it is */
|
| + png_write_complete_chunk(png_ptr, png_tRNS, trans_alpha,
|
| + (png_size_t)num_trans);
|
| + }
|
| +
|
| + else if (color_type == PNG_COLOR_TYPE_GRAY)
|
| + {
|
| + /* One 16-bit value */
|
| + if (tran->gray >= (1 << png_ptr->bit_depth))
|
| + {
|
| + png_app_warning(png_ptr,
|
| + "Ignoring attempt to write tRNS chunk out-of-range for bit_depth");
|
| +
|
| + return;
|
| + }
|
| +
|
| + png_save_uint_16(buf, tran->gray);
|
| + png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)2);
|
| + }
|
| +
|
| + else if (color_type == PNG_COLOR_TYPE_RGB)
|
| + {
|
| + /* Three 16-bit values */
|
| + png_save_uint_16(buf, tran->red);
|
| + png_save_uint_16(buf + 2, tran->green);
|
| + png_save_uint_16(buf + 4, tran->blue);
|
| +#ifdef PNG_WRITE_16BIT_SUPPORTED
|
| + if (png_ptr->bit_depth == 8 && (buf[0] | buf[2] | buf[4]) != 0)
|
| +#else
|
| + if ((buf[0] | buf[2] | buf[4]) != 0)
|
| +#endif
|
| + {
|
| + png_app_warning(png_ptr,
|
| + "Ignoring attempt to write 16-bit tRNS chunk when bit_depth is 8");
|
| + return;
|
| + }
|
| +
|
| + png_write_complete_chunk(png_ptr, png_tRNS, buf, (png_size_t)6);
|
| + }
|
| +
|
| + else
|
| + {
|
| + png_app_warning(png_ptr, "Can't write tRNS with an alpha channel");
|
| + }
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_bKGD_SUPPORTED
|
| +/* Write the background chunk */
|
| +void /* PRIVATE */
|
| +png_write_bKGD(png_structrp png_ptr, png_const_color_16p back, int color_type)
|
| +{
|
| + png_byte buf[6];
|
| +
|
| + png_debug(1, "in png_write_bKGD");
|
| +
|
| + if (color_type == PNG_COLOR_TYPE_PALETTE)
|
| + {
|
| + if (
|
| +#ifdef PNG_MNG_FEATURES_SUPPORTED
|
| + (png_ptr->num_palette != 0 ||
|
| + (png_ptr->mng_features_permitted & PNG_FLAG_MNG_EMPTY_PLTE) == 0) &&
|
| +#endif
|
| + back->index >= png_ptr->num_palette)
|
| + {
|
| + png_warning(png_ptr, "Invalid background palette index");
|
| + return;
|
| + }
|
| +
|
| + buf[0] = back->index;
|
| + png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)1);
|
| + }
|
| +
|
| + else if ((color_type & PNG_COLOR_MASK_COLOR) != 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]) != 0)
|
| +#else
|
| + if ((buf[0] | buf[2] | buf[4]) != 0)
|
| +#endif
|
| + {
|
| + png_warning(png_ptr,
|
| + "Ignoring attempt to write 16-bit bKGD chunk when bit_depth is 8");
|
| +
|
| + return;
|
| + }
|
| +
|
| + png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)6);
|
| + }
|
| +
|
| + else
|
| + {
|
| + if (back->gray >= (1 << png_ptr->bit_depth))
|
| + {
|
| + png_warning(png_ptr,
|
| + "Ignoring attempt to write bKGD chunk out-of-range for bit_depth");
|
| +
|
| + return;
|
| + }
|
| +
|
| + png_save_uint_16(buf, back->gray);
|
| + png_write_complete_chunk(png_ptr, png_bKGD, buf, (png_size_t)2);
|
| + }
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_hIST_SUPPORTED
|
| +/* Write the histogram */
|
| +void /* PRIVATE */
|
| +png_write_hIST(png_structrp png_ptr, png_const_uint_16p hist, int num_hist)
|
| +{
|
| + int i;
|
| + png_byte buf[3];
|
| +
|
| + png_debug(1, "in png_write_hIST");
|
| +
|
| + if (num_hist > (int)png_ptr->num_palette)
|
| + {
|
| + png_debug2(3, "num_hist = %d, num_palette = %d", num_hist,
|
| + png_ptr->num_palette);
|
| +
|
| + png_warning(png_ptr, "Invalid number of histogram entries specified");
|
| + return;
|
| + }
|
| +
|
| + png_write_chunk_header(png_ptr, png_hIST, (png_uint_32)(num_hist * 2));
|
| +
|
| + for (i = 0; i < num_hist; i++)
|
| + {
|
| + png_save_uint_16(buf, hist[i]);
|
| + png_write_chunk_data(png_ptr, buf, (png_size_t)2);
|
| + }
|
| +
|
| + png_write_chunk_end(png_ptr);
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_tEXt_SUPPORTED
|
| +/* Write a tEXt chunk */
|
| +void /* PRIVATE */
|
| +png_write_tEXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
|
| + png_size_t text_len)
|
| +{
|
| + png_uint_32 key_len;
|
| + png_byte new_key[80];
|
| +
|
| + png_debug(1, "in png_write_tEXt");
|
| +
|
| + key_len = png_check_keyword(png_ptr, key, new_key);
|
| +
|
| + if (key_len == 0)
|
| + png_error(png_ptr, "tEXt: invalid keyword");
|
| +
|
| + if (text == NULL || *text == '\0')
|
| + text_len = 0;
|
| +
|
| + else
|
| + text_len = strlen(text);
|
| +
|
| + if (text_len > PNG_UINT_31_MAX - (key_len+1))
|
| + png_error(png_ptr, "tEXt: text too long");
|
| +
|
| + /* Make sure we include the 0 after the key */
|
| + png_write_chunk_header(png_ptr, png_tEXt,
|
| + (png_uint_32)/*checked above*/(key_len + text_len + 1));
|
| + /*
|
| + * We leave it to the application to meet PNG-1.0 requirements on the
|
| + * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
|
| + * any non-Latin-1 characters except for NEWLINE. ISO PNG will forbid them.
|
| + * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
|
| + */
|
| + png_write_chunk_data(png_ptr, new_key, key_len + 1);
|
| +
|
| + if (text_len != 0)
|
| + png_write_chunk_data(png_ptr, (png_const_bytep)text, text_len);
|
| +
|
| + png_write_chunk_end(png_ptr);
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_zTXt_SUPPORTED
|
| +/* Write a compressed text chunk */
|
| +void /* PRIVATE */
|
| +png_write_zTXt(png_structrp png_ptr, png_const_charp key, png_const_charp text,
|
| + int compression)
|
| +{
|
| + png_uint_32 key_len;
|
| + png_byte new_key[81];
|
| + compression_state comp;
|
| +
|
| + png_debug(1, "in png_write_zTXt");
|
| +
|
| + if (compression == PNG_TEXT_COMPRESSION_NONE)
|
| + {
|
| + png_write_tEXt(png_ptr, key, text, 0);
|
| + return;
|
| + }
|
| +
|
| + if (compression != PNG_TEXT_COMPRESSION_zTXt)
|
| + png_error(png_ptr, "zTXt: invalid compression type");
|
| +
|
| + key_len = png_check_keyword(png_ptr, key, new_key);
|
| +
|
| + if (key_len == 0)
|
| + png_error(png_ptr, "zTXt: invalid keyword");
|
| +
|
| + /* Add the compression method and 1 for the keyword separator. */
|
| + new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
|
| + ++key_len;
|
| +
|
| + /* Compute the compressed data; do it now for the length */
|
| + png_text_compress_init(&comp, (png_const_bytep)text,
|
| + text == NULL ? 0 : strlen(text));
|
| +
|
| + if (png_text_compress(png_ptr, png_zTXt, &comp, key_len) != Z_OK)
|
| + png_error(png_ptr, png_ptr->zstream.msg);
|
| +
|
| + /* Write start of chunk */
|
| + png_write_chunk_header(png_ptr, png_zTXt, key_len + comp.output_len);
|
| +
|
| + /* Write key */
|
| + png_write_chunk_data(png_ptr, new_key, key_len);
|
| +
|
| + /* Write the compressed data */
|
| + png_write_compressed_data_out(png_ptr, &comp);
|
| +
|
| + /* Close the chunk */
|
| + png_write_chunk_end(png_ptr);
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_iTXt_SUPPORTED
|
| +/* Write an iTXt chunk */
|
| +void /* PRIVATE */
|
| +png_write_iTXt(png_structrp png_ptr, int compression, png_const_charp key,
|
| + png_const_charp lang, png_const_charp lang_key, png_const_charp text)
|
| +{
|
| + png_uint_32 key_len, prefix_len;
|
| + png_size_t lang_len, lang_key_len;
|
| + png_byte new_key[82];
|
| + compression_state comp;
|
| +
|
| + png_debug(1, "in png_write_iTXt");
|
| +
|
| + key_len = png_check_keyword(png_ptr, key, new_key);
|
| +
|
| + if (key_len == 0)
|
| + png_error(png_ptr, "iTXt: invalid keyword");
|
| +
|
| + /* Set the compression flag */
|
| + switch (compression)
|
| + {
|
| + case PNG_ITXT_COMPRESSION_NONE:
|
| + case PNG_TEXT_COMPRESSION_NONE:
|
| + compression = new_key[++key_len] = 0; /* no compression */
|
| + break;
|
| +
|
| + case PNG_TEXT_COMPRESSION_zTXt:
|
| + case PNG_ITXT_COMPRESSION_zTXt:
|
| + compression = new_key[++key_len] = 1; /* compressed */
|
| + break;
|
| +
|
| + default:
|
| + png_error(png_ptr, "iTXt: invalid compression");
|
| + }
|
| +
|
| + new_key[++key_len] = PNG_COMPRESSION_TYPE_BASE;
|
| + ++key_len; /* for the keywod separator */
|
| +
|
| + /* We leave it to the application to meet PNG-1.0 requirements on the
|
| + * contents of the text. PNG-1.0 through PNG-1.2 discourage the use of
|
| + * any non-Latin-1 characters except for NEWLINE. ISO PNG, however,
|
| + * specifies that the text is UTF-8 and this really doesn't require any
|
| + * checking.
|
| + *
|
| + * The NUL character is forbidden by PNG-1.0 through PNG-1.2 and ISO PNG.
|
| + *
|
| + * TODO: validate the language tag correctly (see the spec.)
|
| + */
|
| + if (lang == NULL) lang = ""; /* empty language is valid */
|
| + lang_len = strlen(lang)+1;
|
| + if (lang_key == NULL) lang_key = ""; /* may be empty */
|
| + lang_key_len = strlen(lang_key)+1;
|
| + if (text == NULL) text = ""; /* may be empty */
|
| +
|
| + prefix_len = key_len;
|
| + if (lang_len > PNG_UINT_31_MAX-prefix_len)
|
| + prefix_len = PNG_UINT_31_MAX;
|
| + else
|
| + prefix_len = (png_uint_32)(prefix_len + lang_len);
|
| +
|
| + if (lang_key_len > PNG_UINT_31_MAX-prefix_len)
|
| + prefix_len = PNG_UINT_31_MAX;
|
| + else
|
| + prefix_len = (png_uint_32)(prefix_len + lang_key_len);
|
| +
|
| + png_text_compress_init(&comp, (png_const_bytep)text, strlen(text));
|
| +
|
| + if (compression != 0)
|
| + {
|
| + if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK)
|
| + png_error(png_ptr, png_ptr->zstream.msg);
|
| + }
|
| +
|
| + else
|
| + {
|
| + if (comp.input_len > PNG_UINT_31_MAX-prefix_len)
|
| + png_error(png_ptr, "iTXt: uncompressed text too long");
|
| +
|
| + /* So the string will fit in a chunk: */
|
| + comp.output_len = (png_uint_32)/*SAFE*/comp.input_len;
|
| + }
|
| +
|
| + png_write_chunk_header(png_ptr, png_iTXt, comp.output_len + prefix_len);
|
| +
|
| + png_write_chunk_data(png_ptr, new_key, key_len);
|
| +
|
| + png_write_chunk_data(png_ptr, (png_const_bytep)lang, lang_len);
|
| +
|
| + png_write_chunk_data(png_ptr, (png_const_bytep)lang_key, lang_key_len);
|
| +
|
| + if (compression != 0)
|
| + png_write_compressed_data_out(png_ptr, &comp);
|
| +
|
| + else
|
| + png_write_chunk_data(png_ptr, (png_const_bytep)text, comp.output_len);
|
| +
|
| + png_write_chunk_end(png_ptr);
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_oFFs_SUPPORTED
|
| +/* Write the oFFs chunk */
|
| +void /* PRIVATE */
|
| +png_write_oFFs(png_structrp png_ptr, png_int_32 x_offset, png_int_32 y_offset,
|
| + int unit_type)
|
| +{
|
| + png_byte buf[9];
|
| +
|
| + png_debug(1, "in png_write_oFFs");
|
| +
|
| + if (unit_type >= PNG_OFFSET_LAST)
|
| + png_warning(png_ptr, "Unrecognized unit type for oFFs chunk");
|
| +
|
| + png_save_int_32(buf, x_offset);
|
| + png_save_int_32(buf + 4, y_offset);
|
| + buf[8] = (png_byte)unit_type;
|
| +
|
| + png_write_complete_chunk(png_ptr, png_oFFs, buf, (png_size_t)9);
|
| +}
|
| +#endif
|
| +#ifdef PNG_WRITE_pCAL_SUPPORTED
|
| +/* Write the pCAL chunk (described in the PNG extensions document) */
|
| +void /* PRIVATE */
|
| +png_write_pCAL(png_structrp png_ptr, png_charp purpose, png_int_32 X0,
|
| + png_int_32 X1, int type, int nparams, png_const_charp units,
|
| + png_charpp params)
|
| +{
|
| + png_uint_32 purpose_len;
|
| + png_size_t units_len, total_len;
|
| + png_size_tp params_len;
|
| + png_byte buf[10];
|
| + png_byte new_purpose[80];
|
| + int i;
|
| +
|
| + png_debug1(1, "in png_write_pCAL (%d parameters)", nparams);
|
| +
|
| + if (type >= PNG_EQUATION_LAST)
|
| + png_error(png_ptr, "Unrecognized equation type for pCAL chunk");
|
| +
|
| + purpose_len = png_check_keyword(png_ptr, purpose, new_purpose);
|
| +
|
| + if (purpose_len == 0)
|
| + png_error(png_ptr, "pCAL: invalid keyword");
|
| +
|
| + ++purpose_len; /* terminator */
|
| +
|
| + png_debug1(3, "pCAL purpose length = %d", (int)purpose_len);
|
| + units_len = strlen(units) + (nparams == 0 ? 0 : 1);
|
| + png_debug1(3, "pCAL units length = %d", (int)units_len);
|
| + total_len = purpose_len + units_len + 10;
|
| +
|
| + params_len = (png_size_tp)png_malloc(png_ptr,
|
| + (png_alloc_size_t)(nparams * (sizeof (png_size_t))));
|
| +
|
| + /* Find the length of each parameter, making sure we don't count the
|
| + * null terminator for the last parameter.
|
| + */
|
| + for (i = 0; i < nparams; i++)
|
| + {
|
| + params_len[i] = strlen(params[i]) + (i == nparams - 1 ? 0 : 1);
|
| + png_debug2(3, "pCAL parameter %d length = %lu", i,
|
| + (unsigned long)params_len[i]);
|
| + total_len += params_len[i];
|
| + }
|
| +
|
| + png_debug1(3, "pCAL total length = %d", (int)total_len);
|
| + png_write_chunk_header(png_ptr, png_pCAL, (png_uint_32)total_len);
|
| + png_write_chunk_data(png_ptr, new_purpose, purpose_len);
|
| + png_save_int_32(buf, X0);
|
| + png_save_int_32(buf + 4, X1);
|
| + buf[8] = (png_byte)type;
|
| + buf[9] = (png_byte)nparams;
|
| + png_write_chunk_data(png_ptr, buf, (png_size_t)10);
|
| + png_write_chunk_data(png_ptr, (png_const_bytep)units, (png_size_t)units_len);
|
| +
|
| + for (i = 0; i < nparams; i++)
|
| + {
|
| + png_write_chunk_data(png_ptr, (png_const_bytep)params[i], params_len[i]);
|
| + }
|
| +
|
| + png_free(png_ptr, params_len);
|
| + png_write_chunk_end(png_ptr);
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_sCAL_SUPPORTED
|
| +/* Write the sCAL chunk */
|
| +void /* PRIVATE */
|
| +png_write_sCAL_s(png_structrp png_ptr, int unit, png_const_charp width,
|
| + png_const_charp height)
|
| +{
|
| + png_byte buf[64];
|
| + png_size_t wlen, hlen, total_len;
|
| +
|
| + png_debug(1, "in png_write_sCAL_s");
|
| +
|
| + wlen = strlen(width);
|
| + hlen = strlen(height);
|
| + total_len = wlen + hlen + 2;
|
| +
|
| + if (total_len > 64)
|
| + {
|
| + png_warning(png_ptr, "Can't write sCAL (buffer too small)");
|
| + return;
|
| + }
|
| +
|
| + buf[0] = (png_byte)unit;
|
| + memcpy(buf + 1, width, wlen + 1); /* Append the '\0' here */
|
| + memcpy(buf + wlen + 2, height, hlen); /* Do NOT append the '\0' here */
|
| +
|
| + png_debug1(3, "sCAL total length = %u", (unsigned int)total_len);
|
| + png_write_complete_chunk(png_ptr, png_sCAL, buf, total_len);
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_pHYs_SUPPORTED
|
| +/* Write the pHYs chunk */
|
| +void /* PRIVATE */
|
| +png_write_pHYs(png_structrp png_ptr, png_uint_32 x_pixels_per_unit,
|
| + png_uint_32 y_pixels_per_unit,
|
| + int unit_type)
|
| +{
|
| + png_byte buf[9];
|
| +
|
| + png_debug(1, "in png_write_pHYs");
|
| +
|
| + if (unit_type >= PNG_RESOLUTION_LAST)
|
| + png_warning(png_ptr, "Unrecognized unit type for pHYs chunk");
|
| +
|
| + png_save_uint_32(buf, x_pixels_per_unit);
|
| + png_save_uint_32(buf + 4, y_pixels_per_unit);
|
| + buf[8] = (png_byte)unit_type;
|
| +
|
| + png_write_complete_chunk(png_ptr, png_pHYs, buf, (png_size_t)9);
|
| +}
|
| +#endif
|
| +
|
| +#ifdef PNG_WRITE_tIME_SUPPORTED
|
| +/* Write the tIME chunk. Use either png_convert_from_struct_tm()
|
| + * or png_convert_from_time_t(), or fill in the structure yourself.
|
| + */
|
| +void /* PRIVATE */
|
| +png_write_tIME(png_structrp png_ptr, png_const_timep mod_time)
|
| +{
|
| + png_byte buf[7];
|
| +
|
| + png_debug(1, "in png_write_tIME");
|
| +
|
| + if (mod_time->month > 12 || mod_time->month < 1 ||
|
| + mod_time->day > 31 || mod_time->day < 1 ||
|
| + mod_time->hour > 23 || mod_time->second > 60)
|
| + {
|
| + png_warning(png_ptr, "Invalid time specified for tIME chunk");
|
| + return;
|
| + }
|
| +
|
| + png_save_uint_16(buf, mod_time->year);
|
| + buf[2] = mod_time->month;
|
| + buf[3] = mod_time->day;
|
| + buf[4] = mod_time->hour;
|
| + buf[5] = mod_time->minute;
|
| + buf[6] = mod_time->second;
|
| +
|
| + png_write_complete_chunk(png_ptr, png_tIME, buf, (png_size_t)7);
|
| +}
|
| +#endif
|
| +
|
| +/* Initializes the row writing capability of libpng */
|
| +void /* PRIVATE */
|
| +png_write_start_row(png_structrp png_ptr)
|
| +{
|
| +#ifdef PNG_WRITE_INTERLACING_SUPPORTED
|
| + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
|
| +
|
| + /* Start of interlace block */
|
| + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
|
| +
|
| + /* Offset to next interlace block */
|
| + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
|
| +
|
| + /* Start of interlace block in the y direction */
|
| + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
|
| +
|
| + /* Offset to next interlace block in the y direction */
|
| + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
|
| +#endif
|
| +
|
| + png_alloc_size_t buf_size;
|
| + int usr_pixel_depth;
|
| +
|
| +#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;
|
| + buf_size = PNG_ROWBYTES(usr_pixel_depth, png_ptr->width) + 1;
|
| +
|
| + /* 1.5.6: added to allow checking in the row write code. */
|
| + png_ptr->transformed_pixel_depth = png_ptr->pixel_depth;
|
| + png_ptr->maximum_pixel_depth = (png_byte)usr_pixel_depth;
|
| +
|
| + /* Set up row buffer */
|
| + png_ptr->row_buf = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
|
| +
|
| + png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE;
|
| +
|
| +#ifdef PNG_WRITE_FILTER_SUPPORTED
|
| + filters = png_ptr->do_filter;
|
| +
|
| + if (png_ptr->height == 1)
|
| + filters &= 0xff & ~(PNG_FILTER_UP|PNG_FILTER_AVG|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)
|
| + {
|
| + int num_filters = 0;
|
| +
|
| + png_ptr->try_row = png_voidcast(png_bytep, png_malloc(png_ptr, buf_size));
|
| +
|
| + if (filters & PNG_FILTER_SUB)
|
| + num_filters++;
|
| +
|
| + if (filters & PNG_FILTER_UP)
|
| + num_filters++;
|
| +
|
| + if (filters & PNG_FILTER_AVG)
|
| + num_filters++;
|
| +
|
| + if (filters & PNG_FILTER_PAETH)
|
| + num_filters++;
|
| +
|
| + if (num_filters > 1)
|
| + png_ptr->tst_row = png_voidcast(png_bytep, png_malloc(png_ptr,
|
| + buf_size));
|
| + }
|
| +
|
| + /* 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 != 0)
|
| + {
|
| + 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];
|
| +
|
| + png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 -
|
| + png_pass_start[0]) / png_pass_inc[0];
|
| + }
|
| +
|
| + else
|
| + {
|
| + png_ptr->num_rows = png_ptr->height;
|
| + png_ptr->usr_width = png_ptr->width;
|
| + }
|
| + }
|
| +
|
| + else
|
| +#endif
|
| + {
|
| + png_ptr->num_rows = png_ptr->height;
|
| + png_ptr->usr_width = png_ptr->width;
|
| + }
|
| +}
|
| +
|
| +/* Internal use only. Called when finished processing a row of data. */
|
| +void /* PRIVATE */
|
| +png_write_finish_row(png_structrp png_ptr)
|
| +{
|
| +#ifdef PNG_WRITE_INTERLACING_SUPPORTED
|
| + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
|
| +
|
| + /* Start of interlace block */
|
| + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
|
| +
|
| + /* Offset to next interlace block */
|
| + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
|
| +
|
| + /* Start of interlace block in the y direction */
|
| + static PNG_CONST png_byte png_pass_ystart[7] = {0, 0, 4, 0, 2, 0, 1};
|
| +
|
| + /* Offset to next interlace block in the y direction */
|
| + static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
|
| +#endif
|
| +
|
| + png_debug(1, "in png_write_finish_row");
|
| +
|
| + /* Next row */
|
| + png_ptr->row_number++;
|
| +
|
| + /* See if we are done */
|
| + if (png_ptr->row_number < png_ptr->num_rows)
|
| + return;
|
| +
|
| +#ifdef PNG_WRITE_INTERLACING_SUPPORTED
|
| + /* If interlaced, go to next pass */
|
| + if (png_ptr->interlaced != 0)
|
| + {
|
| + png_ptr->row_number = 0;
|
| + if ((png_ptr->transformations & PNG_INTERLACE) != 0)
|
| + {
|
| + 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) != 0)
|
| + break;
|
| +
|
| + } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0);
|
| +
|
| + }
|
| +
|
| + /* Reset the row above the image for the next pass */
|
| + if (png_ptr->pass < 7)
|
| + {
|
| + if (png_ptr->prev_row != NULL)
|
| + memset(png_ptr->prev_row, 0,
|
| + (png_size_t)(PNG_ROWBYTES(png_ptr->usr_channels*
|
| + png_ptr->usr_bit_depth, png_ptr->width)) + 1);
|
| +
|
| + return;
|
| + }
|
| + }
|
| +#endif
|
| +
|
| + /* If we get here, we've just written the last row, so we need
|
| + to flush the compressor */
|
| + png_compress_IDAT(png_ptr, NULL, 0, Z_FINISH);
|
| +}
|
| +
|
| +#ifdef PNG_WRITE_INTERLACING_SUPPORTED
|
| +/* Pick out the correct pixels for the interlace pass.
|
| + * The basic idea here is to go through the row with a source
|
| + * pointer and a destination pointer (sp and dp), and copy the
|
| + * correct pixels for the pass. As the row gets compacted,
|
| + * sp will always be >= dp, so we should never overwrite anything.
|
| + * See the default: case for the easiest code to understand.
|
| + */
|
| +void /* PRIVATE */
|
| +png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass)
|
| +{
|
| + /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
|
| +
|
| + /* Start of interlace block */
|
| + static PNG_CONST png_byte png_pass_start[7] = {0, 4, 0, 2, 0, 1, 0};
|
| +
|
| + /* Offset to next interlace block */
|
| + static PNG_CONST png_byte png_pass_inc[7] = {8, 8, 4, 4, 2, 2, 1};
|
| +
|
| + png_debug(1, "in png_do_write_interlace");
|
| +
|
| + /* We don't have to do anything on the last pass (6) */
|
| + if (pass < 6)
|
| + {
|
| + /* Each pixel depth is handled separately */
|
| + switch (row_info->pixel_depth)
|
| + {
|
| + case 1:
|
| + {
|
| + png_bytep sp;
|
| + png_bytep dp;
|
| + unsigned 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;
|
| + unsigned 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;
|
| + unsigned int shift;
|
| + int d;
|
| + int value;
|
| + png_uint_32 i;
|
| + png_uint_32 row_width = row_info->width;
|
| +
|
| + dp = row;
|
| + shift = 4;
|
| + d = 0;
|
| + for (i = png_pass_start[pass]; i < row_width;
|
| + i += png_pass_inc[pass])
|
| + {
|
| + sp = row + (png_size_t)(i >> 1);
|
| + value = (*sp >> ((1 - (int)(i & 0x01)) << 2)) & 0x0f;
|
| + d |= (value << shift);
|
| +
|
| + if (shift == 0)
|
| + {
|
| + shift = 4;
|
| + *dp++ = (png_byte)d;
|
| + d = 0;
|
| + }
|
| +
|
| + else
|
| + shift -= 4;
|
| + }
|
| + if (shift != 4)
|
| + *dp = (png_byte)d;
|
| +
|
| + break;
|
| + }
|
| +
|
| + default:
|
| + {
|
| + png_bytep sp;
|
| + png_bytep dp;
|
| + png_uint_32 i;
|
| + png_uint_32 row_width = row_info->width;
|
| + png_size_t pixel_bytes;
|
| +
|
| + /* Start at the beginning */
|
| + dp = row;
|
| +
|
| + /* Find out how many bytes each pixel takes up */
|
| + pixel_bytes = (row_info->pixel_depth >> 3);
|
| +
|
| + /* Loop through the row, only looking at the pixels that matter */
|
| + for (i = png_pass_start[pass]; i < row_width;
|
| + i += png_pass_inc[pass])
|
| + {
|
| + /* Find out where the original pixel is */
|
| + sp = row + (png_size_t)i * pixel_bytes;
|
| +
|
| + /* Move the pixel */
|
| + if (dp != sp)
|
| + memcpy(dp, sp, pixel_bytes);
|
| +
|
| + /* Next pixel */
|
| + dp += pixel_bytes;
|
| + }
|
| + break;
|
| + }
|
| + }
|
| + /* Set new row width */
|
| + row_info->width = (row_info->width +
|
| + png_pass_inc[pass] - 1 -
|
| + png_pass_start[pass]) /
|
| + png_pass_inc[pass];
|
| +
|
| + row_info->rowbytes = PNG_ROWBYTES(row_info->pixel_depth,
|
| + row_info->width);
|
| + }
|
| +}
|
| +#endif
|
| +
|
| +
|
| +/* This filters the row, chooses which filter to use, if it has not already
|
| + * been specified by the application, and then writes the row out with the
|
| + * chosen filter.
|
| + */
|
| +static void /* PRIVATE */
|
| +png_write_filtered_row(png_structrp png_ptr, png_bytep filtered_row,
|
| + png_size_t row_bytes);
|
| +
|
| +#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_structrp png_ptr, png_row_infop row_info)
|
| +{
|
| +#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");
|
| +
|
| + /* Find out how many bytes offset each pixel is */
|
| + bpp = (row_info->pixel_depth + 7) >> 3;
|
| +
|
| + 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
|
| + * 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.
|
| + */
|
| + best_row = png_ptr->row_buf;
|
| +
|
| +
|
| + if ((filter_to_do & PNG_FILTER_NONE) != 0 && filter_to_do != PNG_FILTER_NONE)
|
| + {
|
| + png_bytep rp;
|
| + png_size_t sum = 0;
|
| + png_size_t i;
|
| + int v;
|
| +
|
| + 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 */
|
| + {
|
| + for (i = 0, rp = row_buf + 1; i < row_bytes; i++, rp++)
|
| + {
|
| + v = *rp;
|
| + sum += (v < 128) ? v : 256 - v;
|
| + }
|
| + }
|
| +
|
| + mins = sum;
|
| + }
|
| +
|
| + /* Sub filter */
|
| + if (filter_to_do == PNG_FILTER_SUB)
|
| + /* It's the only filter so no testing is needed */
|
| + {
|
| + (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) != 0)
|
| + {
|
| + png_size_t sum;
|
| + png_size_t lmins = mins;
|
| +
|
| + sum = png_setup_sub_row(png_ptr, bpp, row_bytes, lmins);
|
| +
|
| + if (sum < mins)
|
| + {
|
| + mins = sum;
|
| + 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)
|
| + {
|
| + (void) png_setup_up_row(png_ptr, row_bytes, mins);
|
| + best_row = png_ptr->try_row;
|
| + }
|
| +
|
| + else if ((filter_to_do & PNG_FILTER_UP) != 0)
|
| + {
|
| + png_size_t sum;
|
| + png_size_t lmins = mins;
|
| +
|
| + sum = png_setup_up_row(png_ptr, row_bytes, lmins);
|
| +
|
| + if (sum < mins)
|
| + {
|
| + mins = sum;
|
| + 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)
|
| + {
|
| + (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) != 0)
|
| + {
|
| + png_size_t sum;
|
| + png_size_t lmins = mins;
|
| +
|
| + sum= png_setup_avg_row(png_ptr, bpp, row_bytes, lmins);
|
| +
|
| + if (sum < mins)
|
| + {
|
| + mins = sum;
|
| + 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) != 0)
|
| + {
|
| + (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) != 0)
|
| + {
|
| + png_size_t sum;
|
| + png_size_t lmins = mins;
|
| +
|
| + sum = png_setup_paeth_row(png_ptr, bpp, row_bytes, lmins);
|
| +
|
| + if (sum < mins)
|
| + {
|
| + 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;
|
| + }
|
| + }
|
| + }
|
| +
|
| + /* 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_structrp png_ptr, png_bytep filtered_row,
|
| + png_size_t full_row_length/*includes filter byte*/)
|
| +{
|
| + png_debug(1, "in png_write_filtered_row");
|
| +
|
| + png_debug1(2, "filter = %d", filtered_row[0]);
|
| +
|
| + png_compress_IDAT(png_ptr, filtered_row, full_row_length, Z_NO_FLUSH);
|
| +
|
| +#ifdef PNG_WRITE_FILTER_SUPPORTED
|
| + /* 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;
|
| + }
|
| +#endif /* WRITE_FILTER */
|
| +
|
| + /* 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 /* WRITE_FLUSH */
|
| +}
|
| +#endif /* WRITE */
|
|
|
Chromium Code Reviews
Issue 2033063003:
Check libpng directly into third_party/ (Closed)
Base URL: https://skia.googlesource.com/skia.git@master