gd_jpeg.c

PHP v6.0 For Linux 运行环境：Win9X/ WinME/ WinNT/ Win2K/ WinXP

			nrows = jpeg_read_scanlines (&cinfo, rowptr, 1);
			if (nrows != 1) {
				php_gd_error_ex(E_WARNING, "gd-jpeg: error: jpeg_read_scanlines returns %u, expected 1", nrows);
				goto error;
			}
			for (j = 0; j < cinfo.output_width; j++, currow += 4, tpix++) {
				*tpix = CMYKToRGB (currow[0], currow[1], currow[2], currow[3], inverted);
			}
		}
	} else {
		for (i = 0; i < cinfo.output_height; i++) {
			register JSAMPROW currow = row;
			register int *tpix = im->tpixels[i];
			nrows = jpeg_read_scanlines (&cinfo, rowptr, 1);
			if (nrows != 1) {
				php_gd_error_ex(E_WARNING, "gd-jpeg: error: jpeg_read_scanlines returns %u, expected 1", nrows);
				goto error;
			}
			for (j = 0; j < cinfo.output_width; j++, currow += 3, tpix++) {
				*tpix = gdTrueColor (currow[0], currow[1], currow[2]);
			}
		}
	} 

	if (jpeg_finish_decompress (&cinfo) != TRUE) {
		php_gd_error("gd-jpeg: warning: jpeg_finish_decompress reports suspended data source");
	}
	if (!ignore_warning) {
		if (cinfo.err->num_warnings > 0) {
			goto error;
		}
	}
	
	jpeg_destroy_decompress (&cinfo);
	gdFree (row);

	return im;

error:
	jpeg_destroy_decompress (&cinfo);
	if (row) {
		gdFree (row);
	}
	if (im) {
		gdImageDestroy (im);
	}
	return 0;
}

/* A very basic conversion approach, TBB */
static int CMYKToRGB(int c, int m, int y, int k, int inverted)
{
	if (inverted) {
		c = 255 - c;
		m = 255 - m;
		y = 255 - y;
		k = 255 - k;
	}
	return gdTrueColor((255 - c) * (255 - k) / 255, (255 - m) * (255 - k) / 255, (255 - y) * (255 - k) / 255);
}

/*
 * gdIOCtx JPEG data sources and sinks, T. Boutell
 * almost a simple global replace from T. Lane's stdio versions.
 *
 */

/* Different versions of libjpeg use either 'jboolean' or 'boolean', and
   some platforms define 'boolean', and so forth. Deal with this
   madness by typedeffing 'safeboolean' to 'boolean' if HAVE_BOOLEAN
   is already set, because this is the test that libjpeg uses.
   Otherwise, typedef it to int, because that's what libjpeg does
   if HAVE_BOOLEAN is not defined. -TBB */

#ifdef HAVE_BOOLEAN
typedef boolean safeboolean;
#else
typedef int safeboolean;
#endif /* HAVE_BOOLEAN */

/* Expanded data source object for gdIOCtx input */

typedef struct
{
	struct jpeg_source_mgr pub;	/* public fields */

	gdIOCtx *infile;		/* source stream */
	unsigned char *buffer;	/* start of buffer */
	safeboolean start_of_file;	/* have we gotten any data yet? */
} my_source_mgr;

typedef my_source_mgr *my_src_ptr;

#define INPUT_BUF_SIZE  4096	/* choose an efficiently fread'able size */

/*
 * Initialize source --- called by jpeg_read_header
 * before any data is actually read.
 */

void init_source (j_decompress_ptr cinfo)
{
	my_src_ptr src = (my_src_ptr) cinfo->src;

	/* We reset the empty-input-file flag for each image,
	 * but we don't clear the input buffer.
	 * This is correct behavior for reading a series of images from one source.
	 */
	src->start_of_file = TRUE;
}


/*
 * Fill the input buffer --- called whenever buffer is emptied.
 *
 * In typical applications, this should read fresh data into the buffer
 * (ignoring the current state of next_input_byte & bytes_in_buffer),
 * reset the pointer & count to the start of the buffer, and return TRUE
 * indicating that the buffer has been reloaded.  It is not necessary to
 * fill the buffer entirely, only to obtain at least one more byte.
 *
 * There is no such thing as an EOF return.  If the end of the file has been
 * reached, the routine has a choice of ERREXIT() or inserting fake data into
 * the buffer.  In most cases, generating a warning message and inserting a
 * fake EOI marker is the best course of action --- this will allow the
 * decompressor to output however much of the image is there.  However,
 * the resulting error message is misleading if the real problem is an empty
 * input file, so we handle that case specially.
 *
 * In applications that need to be able to suspend compression due to input
 * not being available yet, a FALSE return indicates that no more data can be
 * obtained right now, but more may be forthcoming later.  In this situation,
 * the decompressor will return to its caller (with an indication of the
 * number of scanlines it has read, if any).  The application should resume
 * decompression after it has loaded more data into the input buffer.  Note
 * that there are substantial restrictions on the use of suspension --- see
 * the documentation.
 *
 * When suspending, the decompressor will back up to a convenient restart point
 * (typically the start of the current MCU). next_input_byte & bytes_in_buffer
 * indicate where the restart point will be if the current call returns FALSE.
 * Data beyond this point must be rescanned after resumption, so move it to
 * the front of the buffer rather than discarding it.
 */

#define END_JPEG_SEQUENCE "\r\n[*]--:END JPEG:--[*]\r\n"

safeboolean fill_input_buffer (j_decompress_ptr cinfo)
{
	my_src_ptr src = (my_src_ptr) cinfo->src;
	/* 2.0.12: signed size. Thanks to Geert Jansen */
	ssize_t nbytes = 0;

	/* ssize_t got; */
	/* char *s; */
	memset(src->buffer, 0, INPUT_BUF_SIZE);

	while (nbytes < INPUT_BUF_SIZE) {
		int got = gdGetBuf(src->buffer + nbytes, INPUT_BUF_SIZE - nbytes, src->infile);

		if (got == EOF || got == 0) {
			/* EOF or error. If we got any data, don't worry about it. If we didn't, then this is unexpected. */
			if (!nbytes) {
				nbytes = -1;
			}
			break;
		}
		nbytes += got;
	}

	if (nbytes <= 0) {
		if (src->start_of_file)	{ /* Treat empty input file as fatal error */
			ERREXIT (cinfo, JERR_INPUT_EMPTY);
		}
		WARNMS (cinfo, JWRN_JPEG_EOF);
		/* Insert a fake EOI marker */
		src->buffer[0] = (unsigned char) 0xFF;
		src->buffer[1] = (unsigned char) JPEG_EOI;
		nbytes = 2;
	}

	src->pub.next_input_byte = src->buffer;
	src->pub.bytes_in_buffer = nbytes;
	src->start_of_file = FALSE;

	return TRUE;
}


/*
 * Skip data --- used to skip over a potentially large amount of
 * uninteresting data (such as an APPn marker).
 *
 * Writers of suspendable-input applications must note that skip_input_data
 * is not granted the right to give a suspension return.  If the skip extends
 * beyond the data currently in the buffer, the buffer can be marked empty so
 * that the next read will cause a fill_input_buffer call that can suspend.
 * Arranging for additional bytes to be discarded before reloading the input
 * buffer is the application writer's problem.
 */

void skip_input_data (j_decompress_ptr cinfo, long num_bytes)
{
	my_src_ptr src = (my_src_ptr) cinfo->src;

	/* Just a dumb implementation for now. Not clear that being smart is worth
	 * any trouble anyway --- large skips are infrequent.
	 */
	if (num_bytes > 0) {
		while (num_bytes > (long) src->pub.bytes_in_buffer) {
			num_bytes -= (long) src->pub.bytes_in_buffer;
			(void) fill_input_buffer (cinfo);
			/* note we assume that fill_input_buffer will never return FALSE,
			 * so suspension need not be handled.
			 */
		}
		src->pub.next_input_byte += (size_t) num_bytes;
		src->pub.bytes_in_buffer -= (size_t) num_bytes;
	}
}


/*
 * An additional method that can be provided by data source modules is the
 * resync_to_restart method for error recovery in the presence of RST markers.
 * For the moment, this source module just uses the default resync method
 * provided by the JPEG library.  That method assumes that no backtracking
 * is possible.
 */


/*
 * Terminate source --- called by jpeg_finish_decompress
 * after all data has been read.  Often a no-op.
 *
 * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
 * application must deal with any cleanup that should happen even
 * for error exit.
 */

void term_source (j_decompress_ptr cinfo)
{
#if 0
	* never used */
	my_src_ptr src = (my_src_ptr) cinfo->src;
#endif
}


/*
 * Prepare for input from a gdIOCtx stream.
 * The caller must have already opened the stream, and is responsible
 * for closing it after finishing decompression.
 */

void jpeg_gdIOCtx_src (j_decompress_ptr cinfo, gdIOCtx * infile)
{
	my_src_ptr src;

	/* The source object and input buffer are made permanent so that a series
	 * of JPEG images can be read from the same file by calling jpeg_gdIOCtx_src
	 * only before the first one.  (If we discarded the buffer at the end of
	 * one image, we'd likely lose the start of the next one.)
	 * This makes it unsafe to use this manager and a different source
	 * manager serially with the same JPEG object.  Caveat programmer.
	 */
	if (cinfo->src == NULL) { /* first time for this JPEG object? */
		cinfo->src = (struct jpeg_source_mgr *)
		(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, sizeof (my_source_mgr));
		src = (my_src_ptr) cinfo->src;
		src->buffer = (unsigned char *) (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, INPUT_BUF_SIZE * sizeof (unsigned char));

	}

	src = (my_src_ptr) cinfo->src;
	src->pub.init_source = init_source;
	src->pub.fill_input_buffer = fill_input_buffer;
	src->pub.skip_input_data = skip_input_data;
	src->pub.resync_to_restart = jpeg_resync_to_restart;	/* use default method */
	src->pub.term_source = term_source;
	src->infile = infile;
	src->pub.bytes_in_buffer = 0;	/* forces fill_input_buffer on first read */
	src->pub.next_input_byte = NULL;	/* until buffer loaded */
}

/* Expanded data destination object for stdio output */

typedef struct
{
	struct jpeg_destination_mgr pub; /* public fields */
	gdIOCtx *outfile;		 /* target stream */
	unsigned char *buffer;		 /* start of buffer */
} my_destination_mgr;

typedef my_destination_mgr *my_dest_ptr;

#define OUTPUT_BUF_SIZE  4096	/* choose an efficiently fwrite'able size */

/*
 * Initialize destination --- called by jpeg_start_compress
 * before any data is actually written.
 */

void init_destination (j_compress_ptr cinfo)
{
	my_dest_ptr dest = (my_dest_ptr) cinfo->dest;

	/* Allocate the output buffer --- it will be released when done with image */
	dest->buffer = (unsigned char *) (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, OUTPUT_BUF_SIZE * sizeof (unsigned char));

	dest->pub.next_output_byte = dest->buffer;
	dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
}


/*
 * Empty the output buffer --- called whenever buffer fills up.
 *
 * In typical applications, this should write the entire output buffer
 * (ignoring the current state of next_output_byte & free_in_buffer),
 * reset the pointer & count to the start of the buffer, and return TRUE
 * indicating that the buffer has been dumped.
 *
 * In applications that need to be able to suspend compression due to output
 * overrun, a FALSE return indicates that the buffer cannot be emptied now.
 * In this situation, the compressor will return to its caller (possibly with
 * an indication that it has not accepted all the supplied scanlines).  The
 * application should resume compression after it has made more room in the
 * output buffer.  Note that there are substantial restrictions on the use of
 * suspension --- see the documentation.
 *
 * When suspending, the compressor will back up to a convenient restart point
 * (typically the start of the current MCU). next_output_byte & free_in_buffer
 * indicate where the restart point will be if the current call returns FALSE.
 * Data beyond this point will be regenerated after resumption, so do not
 * write it out when emptying the buffer externally.
 */

safeboolean empty_output_buffer (j_compress_ptr cinfo)
{
	my_dest_ptr dest = (my_dest_ptr) cinfo->dest;

	if (gdPutBuf (dest->buffer, OUTPUT_BUF_SIZE, dest->outfile) != (size_t) OUTPUT_BUF_SIZE) {
		ERREXIT (cinfo, JERR_FILE_WRITE);
	}

	dest->pub.next_output_byte = dest->buffer;
	dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;

	return TRUE;
}


/*
 * Terminate destination --- called by jpeg_finish_compress
 * after all data has been written.  Usually needs to flush buffer.
 *
 * NB: *not* called by jpeg_abort or jpeg_destroy; surrounding
 * application must deal with any cleanup that should happen even
 * for error exit.
 */

void term_destination (j_compress_ptr cinfo)
{
	my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
	size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;

	/* Write any data remaining in the buffer */
	if (datacount > 0 && ((size_t)gdPutBuf (dest->buffer, datacount, dest->outfile) != datacount)) {
		ERREXIT (cinfo, JERR_FILE_WRITE);
	}
}


/*
 * Prepare for output to a stdio stream.
 * The caller must have already opened the stream, and is responsible
 * for closing it after finishing compression.
 */

void jpeg_gdIOCtx_dest (j_compress_ptr cinfo, gdIOCtx * outfile)
{
	my_dest_ptr dest;

	/* The destination object is made permanent so that multiple JPEG images
	 * can be written to the same file without re-executing jpeg_stdio_dest.
	 * This makes it dangerous to use this manager and a different destination
	 * manager serially with the same JPEG object, because their private object
	 * sizes may be different.  Caveat programmer.
	 */
	if (cinfo->dest == NULL) { /* first time for this JPEG object? */
		cinfo->dest = (struct jpeg_destination_mgr *) (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, sizeof (my_destination_mgr));
	}

	dest = (my_dest_ptr) cinfo->dest;
	dest->pub.init_destination = init_destination;
	dest->pub.empty_output_buffer = empty_output_buffer;
	dest->pub.term_destination = term_destination;
	dest->outfile = outfile;
}

#endif /* HAVE_JPEG */