"

 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.

"

ImageReader subclass:#JPEGReader

	instanceVariableNames:'jpeg_decompress_struct jpeg_error_mgr_struct colorComponents

		forceGrayscale forceDitherMode'

	classVariableNames:''

	poolDictionaries:''

	category:'Graphics-Images-Support'

!

!JPEGReader primitiveDefinitions!

%{

/*

 * includes, defines, structure definitions

 * and typedefs come here.

 */

#include <stdio.h>

#endif

struct my_error_mgr {

	struct jpeg_error_mgr pub;

	jmp_buf setjmp_buffer;

};

static my_error_exit(cinfo)

    j_common_ptr cinfo;

{

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

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

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

    }

    longjmp(myerrPtr->setjmp_buffer, 1);

}

%}

! !

!JPEGReader primitiveFunctions!

%{

/* 

 * any local C (helper) functions

 * come here (please, define as static)

 */

/*

 * 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) {

      fprintf(stderr, "\rPass %d/%d: %3d%% ",

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

              total_passes, percent_done);

    } else {

      fprintf(stderr, "\r %3d%% ", percent_done);

    }

    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) {

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

    fflush(stderr);

  }

}

#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."

    Image addReader:self suffix:'jpg'.

    Image addReader:self suffix:'jpeg'.

    "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 asLowercase endsWith:'.jpg') ifTrue:[^ true].

    (aFileName 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 = __MKSMALLINT(sizeof(struct my_error_mgr));

    decompressStructSize = __MKSMALLINT(sizeof(struct jpeg_decompress_struct));

%}.

    jpeg_error_mgr_struct := ExternalBytes unprotectedNew:errMgrStructSize.

    jpeg_decompress_struct := ExternalBytes unprotectedNew:decompressStructSize.

    errorOccurred := false.

%{

    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 (__isExternalBytes(j_d_s)

     && __isExternalBytes(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);

	}

        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) = __MKSMALLINT(cinfoPtr->output_width);

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

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

#if 0

        /* could now set additional values in cinfo

         * (colormap)

         */

#endif

    }

%}.

    ^ true

!

decompressChunkInto:aByteArray startingAt:index

%{

    struct jpeg_decompress_struct *cinfoPtr;

    struct my_error_mgr *jerrPtr;

    char *rowPtr;

    OBJ j_d_s = __INST(jpeg_decompress_struct);

    OBJ j_e_m = __INST(jpeg_error_mgr_struct);

    int num_scanlines;

    char *rowPointers[4];

    if (__isExternalBytes(j_d_s)

     && __isByteArray(aByteArray)

     && __isExternalBytes(j_e_m)) {

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

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

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

        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 (__MKSMALLINT(-1));

	    }

            num_scanlines = jpeg_read_scanlines(cinfoPtr, 

                                                rowPointers,

                                                1);

            RETURN (__MKSMALLINT(num_scanlines));

        }

        RETURN (__MKSMALLINT(0));

    }

%}.

    self halt.

!

finish_decompress

%{

    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 (__isExternalBytes(j_d_s)

     && __isExternalBytes(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 (__isExternalBytes(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

%{

    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 (__isExternalBytes(j_d_s)

     && __isExternalBytes(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 from stream'!

fromStream:aStream

    "read a JPG image from a stream"

    |dataIdx bytesPerRow returnCode|

    inStream := aStream.

    (self create_jpeg_decompress_struct not

    or:[self start_decompress not]) ifTrue:[

        'JPEGReader [info]: ' infoPrint. self get_error_message infoPrintCR.

        ^ nil

    ].

    data := ByteArray uninitializedNew:(width * height * colorComponents).

    dataIdx := 1.

    bytesPerRow := colorComponents * width.

    [(returnCode := self decompressChunkInto:data startingAt:dataIdx) > 0] whileTrue:[

        "/ got a row in the buffer ...

        dataIdx := dataIdx + bytesPerRow

    ].    

    returnCode < 0 ifTrue:[

        'JPEGReader [info]: ' infoPrint. self get_error_message infoPrintCR.

        ^ nil

    ].

    (self finish_decompress) ifFalse:[

        'JPEGReader [info]: ' infoPrint. self get_error_message infoPrintCR.

        ^ nil

    ].

    colorComponents == 3 ifTrue:[

        photometric := #rgb.

        samplesPerPixel := 3.

        bitsPerSample := #(8 8 8).

    ] ifFalse:[

        photometric := #blackIs0.

        samplesPerPixel := 1.

        bitsPerSample := #(8).

    ].

    "

     JPEGReader fromFile:'../../support/libjpeg-6a/testimg.jpg'

    "

    "

     |stream reader|