renderpdf.c

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/*====================================================================*
 -  Copyright (C) 2001 Leptonica.  All rights reserved.
 -
 -  Redistribution and use in source and binary forms, with or without
 -  modification, are permitted provided that the following conditions
 -  are met:
 -  1. Redistributions of source code must retain the above copyright
 -     notice, this list of conditions and the following disclaimer.
 -  2. Redistributions in binary form must reproduce the above
 -     copyright notice, this list of conditions and the following
 -     disclaimer in the documentation and/or other materials
 -     provided with the distribution.
 -
 -  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 -  ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 -  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 -  A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL ANY
 -  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 -  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 -  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 -  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 -  OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 -  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 -  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *====================================================================*/
 
#ifdef HAVE_CONFIG_H
#include <config_auto.h>
#endif  /* HAVE_CONFIG_H */
 
#include "allheaders.h"
 
/* --------------------------------------------*/
#if  USE_PDFIO   /* defined in environ.h */
/* --------------------------------------------*/
 
/*-----------------------------------------------------------------*
 *          Rendering pdf files using an external library          *
 *-----------------------------------------------------------------*/
l_ok
l_pdfRenderFile(const char  *filename,
                l_int32      res,
                SARRAY     **psaout)
{
l_int32  ret;
SARRAY  *sain;
 
    if (!psaout)
        return ERROR_INT("&saout not defined", __func__, 1);
    *psaout = NULL;
    if (!filename)
        return ERROR_INT("filename not defined", __func__, 1);
 
    sain = sarrayCreate(1);
    sarrayAddString(sain, filename, L_COPY);
    ret = l_pdfRenderFiles(NULL, sain, res, psaout);
    sarrayDestroy(&sain);
    return ret;
}
 
 
l_ok
l_pdfRenderFiles(const char  *dir,
                 SARRAY      *sain,
                 l_int32      res,
                 SARRAY     **psaout)
{
char     buf[256];
char    *imagedir, *firstfile, *fname, *basename, *tail;
l_int32  i, nfiles, render_res;
SARRAY  *sa;
 
    if (!LeptDebugOK) {
        L_INFO("running pdftoppm is disabled; "
               "use setLeptDebugOK(1) to enable\n", __func__);
        return 0;
    }
 
  #ifdef OS_IOS /* iOS 11 does not support system() */
    return ERROR_INT("iOS 11 does not support system()", __func__, 0);
  #endif /* OS_IOS */
 
    if (!psaout)
        return ERROR_INT("&saout not defined", __func__, 1);
    *psaout = NULL;
    if (res == 0) res = 300;
    if (res < 50 || res > 300)
        return ERROR_INT("res not in range [50 ... 300]", __func__, 1);
    if (!dir && !sain)
        return ERROR_INT("neither dir or sain are defined", __func__, 1);
    if (sain) {
        sa = sarrayCopy(sain);
    } else {
        sa = getSortedPathnamesInDirectory(dir, "pdf", 0, 0);
        if (!sa)
            return ERROR_INT("no files found in dir", __func__, 1);
    }
    nfiles = sarrayGetCount(sa);
 
        /* Set up directory for rendered page images. */
    lept_rmdir("lept/renderpdf");
    lept_mkdir("lept/renderpdf");
    imagedir = genPathname("/tmp/lept/renderpdf", NULL);
 
        /* Figure out the resolution to use with the image renderer.
           This first checks the media box sizes, which give the output
           image size in printer points (1/72 inch).  The largest expected
           output image has a max dimension of about 11 inches, corresponding
           to 792 points.  At a resolution of 300 ppi, the max image size
           is then 3300.  For robustness, use the median of media box sizes.
           If the max dimension of this median is significantly larger than
           792, reduce the input resolution to the renderer. Specifically:
            * Calculate the median of the MediaBox widths and heights.
            * If the max exceeds 850, reduce the resolution so that the max
              dimension of the rendered image is 3300.  The new resolution
              input to the renderer is reduced from 300 by the factor:
                            (792 / medmax)
           If the media boxes are not found, render a page using a small
           given resolution (72) and use the max dimension to find the
           resolution, render_res, that will produce an out with
           3300 pixels in the largest dimension. */
    firstfile = sarrayGetString(sa, 0, L_NOCOPY);
    getPdfRendererResolution(firstfile, imagedir, &render_res);
 
        /* The input %res gives the actual resolution at which the page is
           to be rendered.  If this is less than 300 ppi, reduce render_res,
           the resolution input to pdftoppm, by the factor:
                         (res / 300)                            */
    render_res = (render_res * res) / 300;
 
        /* Rasterize: '-r res' renders output at res ppi
         *  pdftoppm -r res fname outroot    */
    for (i = 0; i < nfiles; i++) {
        fname = sarrayGetString(sa, i, L_NOCOPY);
        splitPathAtDirectory(fname, NULL, &tail);
        splitPathAtExtension(tail, &basename, NULL);
        snprintf(buf, sizeof(buf), "pdftoppm -r %d %s %s/%s",
                 render_res, fname, imagedir, basename);
        lept_free(tail);
        lept_free(basename);
        lept_stderr("%s\n", buf);
        callSystemDebug(buf);   /* pdftoppm */
    }
    sarrayDestroy(&sa);
 
        /* Generate the output array of image file names */
    *psaout = getSortedPathnamesInDirectory(imagedir, NULL, 0, 0);
    lept_free(imagedir);
    return 0;
}
 
 
/* --------------------------------------------*/
#endif  /* USE_PDFIO  */
/* --------------------------------------------*/
 
 
 
/* ------------------------------------------------------------------------- *
 *                       Stubs if pdf is not supported                       *
 * ------------------------------------------------------------------------- */
 
/* -----------------------------------------------------------------*/
#if  !USE_PDFIO
/* -----------------------------------------------------------------*/
 
l_ok l_pdfRenderFile(const char *filename, l_int32 res, SARRAY **psaout)
{
    return ERROR_INT("function not present", __func__, 1);
}
 
/* -----------------------------------------------------------*/
 
l_ok l_pdfRenderFiles(const char *dir, SARRAY *sain, l_int32 res,
                      SARRAY **psaout)
{
    return ERROR_INT("function not present", __func__, 1);
}
 
/* -----------------------------------------------------------------*/
#endif  /* !USE_PDFIO */
/* -----------------------------------------------------------------*/