text: /*
   * wrppm.c
   *
   * Copyright (C) 1991-1996, Thomas G. Lane.
   * Modifided for multibit by Bruce Barton of BITS Limited (shameless plug), 2009, (GPL).
   * This file is part of the Independent JPEG Group's software.
   * For conditions of distribution and use, see the accompanying README file.
   *
   * This file contains routines to write output images in PPM/PGM format.
   * The extended 2-byte-per-sample raw PPM/PGM formats are supported.
   * The PBMPLUS library is NOT required to compile this software
   * (but it is highly useful as a set of PPM image manipulation programs).
   *
   * These routines may need modification for non-Unix environments or
   * specialized applications.  As they stand, they assume output to
   * an ordinary stdio stream.
   */
  
  #include "cdjpeg.h"		/* Common decls for cjpeg/djpeg applications */
  
  #ifdef PPM_SUPPORTED
  
  
  /*
   * For 12-bit JPEG data, we either downscale the values to 8 bits
   * (to write standard byte-per-sample PPM/PGM files), or output
   * nonstandard word-per-sample PPM/PGM files.  Downscaling is done
   * if PPM_NORAWWORD is defined (this can be done in the Makefile
   * or in jconfig.h).
   * (When the core library supports data precision reduction, a cleaner
   * implementation will be to ask for that instead.)
   */
  
  /*#if BITS_IN_JSAMPLE == 8
  #define PUTPPMSAMPLE(ptr,v)  *ptr++ = (char) (v)
  #define BYTESPERSAMPLE 1
  #define PPM_MAXVAL 255
  #else
  #ifdef PPM_NORAWWORD
  #define PUTPPMSAMPLE(ptr,v)  *ptr++ = (char) ((v) >> (cinfo->data_precision-8))
  #define BYTESPERSAMPLE 1
  #define PPM_MAXVAL 255
  #else*/
  /* The word-per-sample format always puts the LSB first. */
  /*#define PUTPPMSAMPLE(ptr,v)			\
  	{ register int val_ = v;		\
  	  *ptr++ = (char) (val_ & 0xFF);	\
  	  *ptr++ = (char) ((val_ >> 8) & 0xFF);	\
  	}
  #define BYTESPERSAMPLE 2
  #define PPM_MAXVAL ((1<<cinfo->data_precision)-1)
  #endif
  #endif*/
  
  
  /*
   * When JSAMPLE is the same size as char, we can just fwrite() the
   * decompressed data to the PPM or PGM file.  On PCs, in order to make this
   * work the output buffer must be allocated in near data space, because we are
   * assuming small-data memory model wherein fwrite() can't reach far memory.
   * If you need to process very wide images on a PC, you might have to compile
   * in large-memory model, or else replace fwrite() with a putc() loop ---
   * which will be much slower.
   */
  
  
  /* Private version of data destination object */
  
  typedef struct {
    struct djpeg_dest_struct pub;	/* public fields */
  
    /* Usually these two pointers point to the same place: */
    char *iobuffer;		/* fwrite's I/O buffer */
  /*  JSAMPROW16 pixrow;*/		/* decompressor output buffer */
    size_t buffer_width;		/* width of I/O buffer */
    JDIMENSION samples_per_row;	/* JSAMPLEs per output row */
  } ppm_dest_struct;
  
  typedef ppm_dest_struct * ppm_dest_ptr;
  
  
  /*
   * Write some pixel data.
   * In this module rows_supplied will always be 1.
   *
   * put_pixel_rows handles the "normal" 8-bit case where the decompressor
   * output buffer is physically the same as the fwrite buffer.
   */
  
  /*METHODDEF(void)
  put_pixel_rows (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
  		JDIMENSION rows_supplied)
  {
    ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
  
    (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
  }*/
  
  
  /*
   * This code is used when we have to copy the data and apply a pixel
   * format translation.  Typically this only happens in 12-bit mode.
   */
  
  METHODDEF(void)
  copy_pixel_rows8 (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
  		 JDIMENSION rows_supplied)
  {
    ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
    register char * bufferptr;
    register JSAMPROW16 ptr;
    register JDIMENSION col;
  
    ptr = (JSAMPROW16)dest->pub.buffer[0];
    bufferptr = dest->iobuffer;
    for (col = dest->samples_per_row; col > 0; col--) {
      *bufferptr++ = (char)GETJSAMPLE(*ptr++);
    }
    (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
  }
  
  METHODDEF(void)
  copy_pixel_rows16 (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
  		 JDIMENSION rows_supplied)
  {
    ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
    register char * bufferptr;
    register JSAMPROW16 ptr;
    register JDIMENSION col;
    register int val;
  
    ptr = (JSAMPROW16)dest->pub.buffer[0];
    bufferptr = dest->iobuffer;
    for (col = dest->samples_per_row; col > 0; col--) {
      val = GETJSAMPLE(*ptr++);
  	*bufferptr++ = (char)((val >> 8) & 0xFF);
  	*bufferptr++ = (char)(val & 0xFF);
    }
    (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
  }
  
  /*
   * Write some pixel data when color quantization is in effect.
   * We have to demap the color index values to straight data.
   */
  
  METHODDEF(void)
  put_demapped_rgb8 (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
  		  JDIMENSION rows_supplied)
  {
    ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
    register char * bufferptr;
    register int pixval;
    register JSAMPROW16 ptr;
    register JSAMPROW16 color_map0 = cinfo->colormap16[0];
    register JSAMPROW16 color_map1 = cinfo->colormap16[1];
    register JSAMPROW16 color_map2 = cinfo->colormap16[2];
    register JDIMENSION col;
  
    ptr = (JSAMPROW16)dest->pub.buffer[0];
    bufferptr = dest->iobuffer;
    for (col = cinfo->output_width; col > 0; col--) {
      pixval = GETJSAMPLE(*ptr++);
      *bufferptr++ = (char)GETJSAMPLE(color_map0[pixval]);
      *bufferptr++ = (char)GETJSAMPLE(color_map1[pixval]);
      *bufferptr++ = (char)GETJSAMPLE(color_map2[pixval]);
    }
    (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
  }
  
  METHODDEF(void)
  put_demapped_rgb16 (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
  		  JDIMENSION rows_supplied)
  {
    ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
    register char * bufferptr;
    register int pixval, val;
    register JSAMPROW16 ptr;
    register JSAMPROW16 color_map0 = cinfo->colormap16[0];
    register JSAMPROW16 color_map1 = cinfo->colormap16[1];
    register JSAMPROW16 color_map2 = cinfo->colormap16[2];
    register JDIMENSION col;
  
    ptr = (JSAMPROW16)dest->pub.buffer[0];
    bufferptr = dest->iobuffer;
    for (col = cinfo->output_width; col > 0; col--) {
      pixval = GETJSAMPLE(*ptr++);
  	val = GETJSAMPLE(color_map0[pixval]);
  	*bufferptr++ = (char)((val >> 8) & 0xFF);
  	*bufferptr++ = (char)(val & 0xFF);
      val = GETJSAMPLE(color_map1[pixval]);
  	*bufferptr++ = (char)((val >> 8) & 0xFF);
  	*bufferptr++ = (char)(val & 0xFF);
      val = GETJSAMPLE(color_map2[pixval]);
  	*bufferptr++ = (char)((val >> 8) & 0xFF);
  	*bufferptr++ = (char)(val & 0xFF);
    }
    (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
  }
  
  METHODDEF(void)
  put_demapped_gray8 (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
  		   JDIMENSION rows_supplied)
  {
    ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
    register char * bufferptr;
    register JSAMPROW16 ptr;
    register JSAMPROW16 color_map = cinfo->colormap16[0];
    register JDIMENSION col;
  
    ptr = (JSAMPROW16)dest->pub.buffer[0];
    bufferptr = dest->iobuffer;
    for (col = cinfo->output_width; col > 0; col--) {
      *bufferptr++ = (char)GETJSAMPLE(color_map[GETJSAMPLE(*ptr++)]);
    }
    (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
  }
  
  METHODDEF(void)
  put_demapped_gray16 (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo,
  		   JDIMENSION rows_supplied)
  {
    ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
    register char * bufferptr;
    register JSAMPROW16 ptr;
    register JSAMPROW16 color_map = cinfo->colormap16[0];
    register JDIMENSION col;
    register int val;
  
    ptr = (JSAMPROW16)dest->pub.buffer[0];
    bufferptr = dest->iobuffer;
    for (col = cinfo->output_width; col > 0; col--) {
  	val = GETJSAMPLE(color_map[GETJSAMPLE(*ptr++)]);
  	*bufferptr++ = (char)((val >> 8) & 0xFF);
  	*bufferptr++ = (char)(val & 0xFF);
    }  
    (void) JFWRITE(dest->pub.output_file, dest->iobuffer, dest->buffer_width);
  }
  
  
  /*
   * Startup: write the file header.
   */
  
  METHODDEF(void)
  start_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
  {
    ppm_dest_ptr dest = (ppm_dest_ptr) dinfo;
    int ppm_maxval;
    
    /* Create physical I/O buffer.  Note we make this near on a PC. */
    cinfo->buffer_size_char = FALSE; /* JSAMPLE16 buffer sent. */
    if (cinfo->data_precision_other <= 8)
      dest->buffer_width = dest->samples_per_row * SIZEOF(char);
    else dest->buffer_width = dest->samples_per_row * SIZEOF(JSAMPLE16);
    dest->iobuffer = (char *) (*cinfo->mem->alloc_small)
      ((j_common_ptr) cinfo, JPOOL_IMAGE, dest->buffer_width);
      
    ppm_maxval = (1<<cinfo->data_precision_other)-1;
    
    /* Emit file header */
    switch (cinfo->out_color_space) {
    case JCS_GRAYSCALE:
      /* emit header for raw PGM format */
      fprintf(dest->pub.output_file, "P5\n%ld %ld\n%d\n",
  	    (long) cinfo->output_width, (long) cinfo->output_height,
  	    ppm_maxval);
      break;
    case JCS_RGB:
      /* emit header for raw PPM format */
      fprintf(dest->pub.output_file, "P6\n%ld %ld\n%d\n",
  	    (long) cinfo->output_width, (long) cinfo->output_height,
  	    ppm_maxval);
      break;
    default:
      ERREXIT(cinfo, JERR_PPM_COLORSPACE);
    }
  }
  
  
  /*
   * Finish up at the end of the file.
   */
  
  METHODDEF(void)
  finish_output_ppm (j_decompress_ptr cinfo, djpeg_dest_ptr dinfo)
  {
    /* Make sure we wrote the output file OK */
    fflush(dinfo->output_file);
    if (ferror(dinfo->output_file))
      ERREXIT(cinfo, JERR_FILE_WRITE);
  }
  
  
  /*
   * The module selection routine for PPM format output.
   */
  
  GLOBAL(djpeg_dest_ptr)
  jinit_write_ppm (j_decompress_ptr cinfo)
  {
    ppm_dest_ptr dest;
  
    /* Create module interface object, fill in method pointers */
    dest = (ppm_dest_ptr)
        (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
  				  SIZEOF(ppm_dest_struct));
    dest->pub.start_output = start_output_ppm;
    dest->pub.finish_output = finish_output_ppm;
  
    /* Calculate output image dimensions so we can allocate space */
    jpeg_calc_output_dimensions(cinfo);
  
    /* Dimensions for the physical I/O buffer. */
    dest->samples_per_row = cinfo->output_width * cinfo->out_color_components;
  
    /* A JSAMPLE16 buffer for decompression now that jdapistd take it.
     * Conversion to 8 bit if needed is done later with copy or put 8.
     * Scaling is now done by the jpeg library. */
    dest->pub.buffer = (*cinfo->mem->alloc_sarray)
      ((j_common_ptr) cinfo, JPOOL_IMAGE,
      (JDIMENSION) cinfo->output_width * cinfo->output_components
      * SIZEOF(JSAMPLE16),(JDIMENSION) 1);
    dest->pub.buffer_height = 1;
  	
    if (cinfo->data_precision_other <= 8) {
      if (cinfo->quantize_colors) {
        if (cinfo->out_color_space == JCS_GRAYSCALE)
         dest->pub.put_pixel_rows = put_demapped_gray8;
  	  else dest->pub.put_pixel_rows = put_demapped_rgb8; /* Maped color */
      } else dest->pub.put_pixel_rows = copy_pixel_rows8; /* Default 8 bit */
    } else { /* > 8 bit output */
  	if (cinfo->quantize_colors) {
  	  if (cinfo->out_color_space == JCS_GRAYSCALE)
  	    dest->pub.put_pixel_rows = put_demapped_gray16;
  	  else dest->pub.put_pixel_rows = put_demapped_rgb16;
  	} else dest->pub.put_pixel_rows = copy_pixel_rows16; /* No quanttize */
    }
    
    return (djpeg_dest_ptr) dest;
  }
  
  #endif /* PPM_SUPPORTED */
  