"

 COPYRIGHT (c) 1993 by Claus Gittinger

	      All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

"{ Package: 'stx:libview2' }"

ImageReader subclass:#JPEGReader

	instanceVariableNames:'jpeg_decompress_struct jpeg_error_mgr_struct colorComponents

		forceGrayscale forceDitherMode'

	classVariableNames:'ErrorPrinting'

	poolDictionaries:''

	category:'Graphics-Images-Readers'

!

!JPEGReader primitiveDefinitions!

%{

/*

 * includes, defines, structure definitions

 * and typedefs come here.

 */

#include <stdio.h>

#ifdef sunos

# include <sys/types.h>

#endif

#include <jpeglib.h>

#include <jerror.h>

struct my_error_mgr {

	struct jpeg_error_mgr pub;

	jmp_buf setjmp_buffer;

};

%}

! !

!JPEGReader primitiveFunctions!

%{

/*

 * any local C (helper) functions

 * come here (please, define as static)

 */

static

my_error_exit(cinfo)

    j_common_ptr cinfo;

{

    struct my_error_mgr *myerrPtr = (struct my_error_mgr *) cinfo->err;

    if (@global(ErrorPrinting) == true) {

	console_fprintf(stderr, "JPEGReader [warning]: jpeg error\n");

    }

    longjmp(myerrPtr->setjmp_buffer, 1);

}

static

my_output_message(cinfo)

    j_common_ptr cinfo;

{

    char buffer[JMSG_LENGTH_MAX];

    if (@global(ErrorPrinting) == true) {

	console_fprintf(stderr, "libJPEG [error]: ");

       /* Create the message */

       (*cinfo->err->format_message) (cinfo, buffer);

       /* Send it to stderr, adding a newline */

       console_fprintf(stderr, "%s\n", buffer);

    }

}

/*

 * Optional progress monitor: display a percent-done figure on stderr.

 */

#ifdef PROGRESS_REPORT

void

JPG_progress_monitor (j_common_ptr cinfo)

{

  cd_progress_ptr prog = (cd_progress_ptr) cinfo->progress;

  int total_passes = prog->pub.total_passes + prog->total_extra_passes;

  int percent_done = (int) (prog->pub.pass_counter*100L/prog->pub.pass_limit);

  if (percent_done != prog->percent_done) {

    prog->percent_done = percent_done;

    if (total_passes > 1) {

      console_fprintf("\rPass %d/%d: %3d%% ",

	      prog->pub.completed_passes + prog->completed_extra_passes + 1,

	      total_passes, percent_done);

    } else {

      console_fprintf("\r %3d%% ", percent_done);

    }

    console_fflush(stderr);

  }

}

void

JPG_start_progress_monitor (j_common_ptr cinfo, cd_progress_ptr progress)

{

  /* Enable progress display, unless trace output is on */

  if (cinfo->err->trace_level == 0) {

    progress->pub.progress_monitor = progress_monitor;

    progress->completed_extra_passes = 0;

    progress->total_extra_passes = 0;

    progress->percent_done = -1;

    cinfo->progress = &progress->pub;

  }

}

void

JPG_end_progress_monitor (j_common_ptr cinfo)

{

  /* Clear away progress display */

  if (cinfo->err->trace_level == 0) {

    console_fprintf(stderr, "\r                \r");

  }

}

#endif

%}

! !

!JPEGReader class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1993 by Claus Gittinger

	      All Rights Reserved

 This software is furnished under a license and may be used

 only in accordance with the terms of that license and with the

 inclusion of the above copyright notice.   This software may not

 be provided or otherwise made available to, or used by, any

 other person.  No title to or ownership of the software is

 hereby transferred.

"

!

documentation

"

    Reader for JPEG images.

    This uses the libpeg library to read the image

    Only reading of files is supported.

    [See also:]

	Image Form Icon

	BlitImageReader FaceReader GIFReader PBMReader PCXReader

	ST80FormReader SunRasterReader TargaReader TIFFReader WindowsIconReader

	XBMReader XPMReader XWDReader

"

! !

!JPEGReader class methodsFor:'initialization'!

initialize

    "install myself in the Image classes fileFormat table

     for the `.jpg' and '.jpeg' extensions."

    MIMETypes defineImageType:'image/jpeg' suffix:'jpg'  reader:self.

    MIMETypes defineImageType:nil          suffix:'jpeg' reader:self.

    "Modified: 1.2.1997 / 15:01:55 / cg"

! !

!JPEGReader class methodsFor:'testing'!

isValidImageFile:aFileName

    "return true, if aFileName contains a JPG image.

     Only look at the files name here ..."

    (aFileName asString asLowercase endsWith:'.jpg') ifTrue:[^ true].

    (aFileName asString asLowercase endsWith:'.jpeg') ifTrue:[^ true].

    ^ false

    "Created: 11.4.1997 / 16:26:25 / cg"

! !

!JPEGReader methodsFor:'accessing'!

forceDitherMode:something

    "set the dither mode, to one of #none or #ordered"

    forceDitherMode := something.

    "Modified: 16.4.1997 / 20:34:59 / cg"

!

forceGrayscale:something

    "set the forceGrayscale mode; if true, grayScale images are

     returned, even if the input contains a color image."

    forceGrayscale := something.

    "Created: 16.4.1997 / 20:33:44 / cg"

    "Modified: 16.4.1997 / 20:34:29 / cg"

! !

!JPEGReader methodsFor:'private'!

create_jpeg_decompress_struct

    |errMgrStructSize decompressStructSize fp errorOccurred|

    fp := inStream filePointer.

    fp isNil ifTrue:[

	self error:'can only read from an external stream'.

	^ self.

    ].

%{

    errMgrStructSize = __mkSmallInteger(sizeof(struct my_error_mgr));

    decompressStructSize = __mkSmallInteger(sizeof(struct jpeg_decompress_struct));

%}.

    jpeg_error_mgr_struct := ExternalBytes unprotectedNew:errMgrStructSize.

    jpeg_decompress_struct := ExternalBytes unprotectedNew:decompressStructSize.

    errorOccurred := false.

%{  /* STACK: 400000 */

    struct jpeg_decompress_struct *cinfoPtr;

    struct my_error_mgr *jerrPtr;

    OBJ j_e_m = __INST(jpeg_error_mgr_struct);

    OBJ j_d_s = __INST(jpeg_decompress_struct);

    FILE *f = __FILEVal(fp);

    if (__isExternalBytesLike(j_d_s)

     && __isExternalBytesLike(j_e_m)) {

	cinfoPtr = (struct jpeg_decompress_struct *)(__externalBytesAddress(j_d_s));

	jerrPtr = (struct my_error_mgr *)(__externalBytesAddress(j_e_m));

	/*

	 * Initialize the JPEG decompression object with default error handling.

	 */

	cinfoPtr->err = jpeg_std_error(jerrPtr);

	/*

	 * prepare to handle errors smoothly ...

	 */

	jerrPtr->pub.error_exit = my_error_exit;

	if (setjmp(jerrPtr->setjmp_buffer)) {

	    /*

	     * error occurred ...

	     */

	    jpeg_destroy_decompress(cinfoPtr);

	    RETURN (false);

	}

       /*

	* use my message print function

	*/

       jerrPtr->pub.output_message = my_output_message;

	jpeg_create_decompress(cinfoPtr);

#if 0

	/*

	 * Insert custom COM marker processor.

	 */

	jpeg_set_marker_processor(cinfoPtr, JPEG_COM, COM_handler);

#endif

	cinfoPtr->err->trace_level = 0;

#if 0

	/* colors setting */

	cinfoPtr->desired_number_of_colors = val;

	cinfoPtr->quantize_colors = TRUE;

#endif

#if 0

	/* dct setting */

	cinfoPtr->dct_method = JDCT_ISLOW;

	or: cinfoPtr->dct_method = JDCT_IFAST;

	or: cinfoPtr->dct_method = JDCT_FLOAT;

#endif

	/* dither setting */

	cinfoPtr->dither_mode = JDITHER_FS;

	if (__INST(forceDitherMode) == @symbol(none)) {

	    cinfoPtr->dither_mode = JDITHER_NONE;

	} else {

	    if (__INST(forceDitherMode) == @symbol(ordered)) {

		cinfoPtr->dither_mode = JDITHER_ORDERED;

	    }

	}

#if 0

	/* fast setting */

	cinfoPtr->two_pass_quantize = FALSE;

	cinfoPtr->dither_mode = JDITHER_ORDERED;

	cinfoPtr->desired_number_of_colors = 216;

	cinfoPtr->dct_method = JDCT_FASTEST;

	cinfoPtr->do_fancy_upsampling = FALSE;

#endif

	if (__INST(forceGrayscale) == true) {

	    /* grayscale setting */

	    cinfoPtr->out_color_space = JCS_GRAYSCALE;

	}

#if 0

	/* maxmemory setting */

	cinfoPtr->mem->max_memory_to_use = lval * 1000L;

#endif

#if 0

	/* nosmooth setting */

	cinfoPtr->do_fancy_upsampling = FALSE;

#endif

#if 0

	/* onepass setting */

	cinfoPtr->two_pass_quantize = FALSE;

#endif

	/* Specify data source for decompression */

	jpeg_stdio_src(cinfoPtr, f);

	/* Read file header, set default decompression parameters */

	(void) jpeg_read_header(cinfoPtr, TRUE);

	/* Calculate output image dimensions so we can allocate space */

	jpeg_calc_output_dimensions(cinfoPtr);

	__INST(width) = __mkSmallInteger(cinfoPtr->output_width);

	__INST(height) = __mkSmallInteger(cinfoPtr->output_height);

	__INST(colorComponents) = __mkSmallInteger(cinfoPtr->output_components);

#if 0

	/* could now set additional values in cinfo

	 * (colormap)

	 */

#endif

    }

%}.

    ^ true

!

decompressChunkInto:aByteArray startingAt:index

%{  /* STACK: 400000 */

    struct jpeg_decompress_struct *cinfoPtr;

    struct my_error_mgr *jerrPtr;

    char *rowPtr = NULL;

    OBJ j_d_s = __INST(jpeg_decompress_struct);

    OBJ j_e_m = __INST(jpeg_error_mgr_struct);

    int num_scanlines;

    char *rowPointers[4];

    if (__isByteArray(aByteArray)) {

	rowPtr = (char *)(__ByteArrayInstPtr(aByteArray)->ba_element);

    } else if (__isExternalBytesLike(aByteArray)) {

	rowPtr = __externalBytesAddress(aByteArray);

    }

    if (__isExternalBytesLike(j_d_s)

     && (rowPtr != NULL)

     && __isExternalBytesLike(j_e_m)) {

	cinfoPtr = (struct jpeg_decompress_struct *)(__externalBytesAddress(j_d_s));

	jerrPtr = (struct my_error_mgr *)(__externalBytesAddress(j_e_m));

	rowPtr += __intVal(index) - 1;

	rowPointers[0] = rowPtr;

	rowPointers[1] = NULL;

	rowPointers[2] = NULL;

	rowPointers[3] = NULL;

	if (cinfoPtr->output_scanline < cinfoPtr->output_height) {

	    if (setjmp(jerrPtr->setjmp_buffer)) {

		/*

		 * error occurred ...

		 */

		jpeg_destroy_decompress(cinfoPtr);

		RETURN (__mkSmallInteger(-1));

	    }

	    num_scanlines = jpeg_read_scanlines(cinfoPtr,

						rowPointers,

						1);

	    RETURN (__mkSmallInteger(num_scanlines));

	}

	RETURN (__mkSmallInteger(0));

    }

%}.

    self halt:'bad arguments'.

!

finish_decompress

%{  /* STACK: 400000 */

    struct jpeg_decompress_struct *cinfoPtr;

    struct my_error_mgr *jerrPtr;

    OBJ j_d_s = __INST(jpeg_decompress_struct);

    OBJ j_e_m = __INST(jpeg_error_mgr_struct);

    if (__isExternalBytesLike(j_d_s)

     && __isExternalBytesLike(j_e_m)) {

	cinfoPtr = (struct jpeg_decompress_struct *)(__externalBytesAddress(j_d_s));

	jerrPtr = (struct my_error_mgr *)(__externalBytesAddress(j_e_m));

	if (setjmp(jerrPtr->setjmp_buffer)) {

	    jpeg_destroy_decompress(cinfoPtr);

	    RETURN (false);

	}

	/* finish decompressor */

	(void) jpeg_finish_decompress(cinfoPtr);

	(void) jpeg_destroy_decompress(cinfoPtr);

	RETURN (true);

    }

%}

!

get_error_message

%{

    struct jpeg_decompress_struct *cinfoPtr;

    OBJ j_d_s = __INST(jpeg_decompress_struct);

    char buffer[JMSG_LENGTH_MAX+1];

    if (__isExternalBytesLike(j_d_s)) {

	cinfoPtr = (struct jpeg_decompress_struct *)(__externalBytesAddress(j_d_s));

	(*cinfoPtr->err->format_message) (cinfoPtr, buffer);

	buffer[JMSG_LENGTH_MAX] = '\0';

	RETURN ( __MKSTRING(buffer));

    }

%}.

    ^ nil

!

start_decompress

%{  /* STACK: 400000 */

    struct jpeg_decompress_struct *cinfoPtr;

    struct my_error_mgr *jerrPtr;

    OBJ j_d_s = __INST(jpeg_decompress_struct);

    OBJ j_e_m = __INST(jpeg_error_mgr_struct);

    if (__isExternalBytesLike(j_d_s)

     && __isExternalBytesLike(j_e_m)) {

	cinfoPtr = (struct jpeg_decompress_struct *)(__externalBytesAddress(j_d_s));

	jerrPtr = (struct my_error_mgr *)(__externalBytesAddress(j_e_m));

	if (setjmp(jerrPtr->setjmp_buffer)) {

	    jpeg_destroy_decompress(cinfoPtr);

	    RETURN (false);

	}

	/* Start decompressor */

	(void) jpeg_start_decompress(cinfoPtr);

	RETURN (true);

    }

%}

! !

!JPEGReader methodsFor:'reading'!

fromStream:aStream

    "read a JPG image from a stream"

    |dataIdx bytesPerRow returnCode pos1 ok tmpFile s|

    aStream isExternalStream ifFalse:[

	"/ libJpeg can only handle real OS-streams

	tmpFile := Filename newTemporary.

	[

	    s := tmpFile writeStream binary.

	    s nextPutAll:aStream contents.