WDL/lice/lice_jpg_write.cpp

   1 /*
   2   Cockos WDL - LICE - Lightweight Image Compositing Engine
   3   Copyright (C) 2007 and later, Cockos Incorporated
   4   File: lice_jpg_write.cpp (JPG writing for LICE)
   5   See lice.h for license and other information
   6 */
   7
   8 #include <stdio.h>
   9 #include "lice.h"
  10 #include <setjmp.h>
  11
  12 extern "C" {
  13 #include "../jpeglib/jpeglib.h"
  14 };
  15
  16 struct my_error_mgr {
  17   struct jpeg_error_mgr pub;    /* "public" fields */
  18   jmp_buf setjmp_buffer;        /* for return to caller */
  19 };
  20 static void LICEJPEG_Error(j_common_ptr cinfo)
  21 {
  22   longjmp(((my_error_mgr*)cinfo->err)->setjmp_buffer,1);
  23 }
  24 static void LICEJPEG_EmitMsg(j_common_ptr cinfo, int msg_level) { }
  25 static void LICEJPEG_FmtMsg(j_common_ptr cinfo, char *) { }
  26 static void LICEJPEG_OutMsg(j_common_ptr cinfo) { }
  27 static void LICEJPEG_reset_error_mgr(j_common_ptr cinfo)
  28 {
  29   cinfo->err->num_warnings = 0;
  30   cinfo->err->msg_code = 0;
  31 }
  32
  33 bool LICE_WriteJPG(const char *filename, LICE_IBitmap *bmp, int quality, bool force_baseline)
  34 {
  35   if (!bmp || !filename) return false;
  36
  37   FILE *fp=NULL;
  38 #if defined(_WIN32) && !defined(WDL_NO_SUPPORT_UTF8)
  39   #ifdef WDL_SUPPORT_WIN9X
  40   if (GetVersion()<0x80000000)
  41   #endif
  42   {
  43     WCHAR wf[2048];
  44     if (MultiByteToWideChar(CP_UTF8,MB_ERR_INVALID_CHARS,filename,-1,wf,2048))
  45       fp = _wfopen(wf,L"wb");
  46   }
  47 #endif
  48   if (!fp) fp = fopen(filename,"wb");
  49
  50   if (!fp) return false;
  51
  52   struct jpeg_compress_struct cinfo;
  53   struct my_error_mgr jerr={0,};
  54   jerr.pub.error_exit = LICEJPEG_Error;
  55   jerr.pub.emit_message = LICEJPEG_EmitMsg;
  56   jerr.pub.output_message = LICEJPEG_OutMsg;
  57   jerr.pub.format_message = LICEJPEG_FmtMsg;
  58   jerr.pub.reset_error_mgr = LICEJPEG_reset_error_mgr;
  59
  60   cinfo.err = &jerr.pub;
  61   unsigned char *buf = NULL;
  62
  63   if (setjmp(jerr.setjmp_buffer))
  64   {
  65     jpeg_destroy_compress(&cinfo);
  66     if (fp) fclose(fp);
  67     free(buf);
  68     return false;
  69   }
  70   jpeg_create_compress(&cinfo);
  71
  72   jpeg_stdio_dest(&cinfo, fp);
  73
  74   cinfo.image_width = bmp->getWidth();  /* image width and height, in pixels */
  75   cinfo.image_height = bmp->getHeight();
  76   cinfo.input_components = 3;           /* # of color components per pixel */
  77   cinfo.in_color_space = JCS_RGB;       /* colorspace of input image */
  78
  79   jpeg_set_defaults(&cinfo);
  80   jpeg_set_quality(&cinfo, quality, !!force_baseline);
  81   jpeg_start_compress(&cinfo, TRUE);
  82
  83   buf = (unsigned char *)malloc(cinfo.image_width * 3);
  84   LICE_pixel_chan *rd = (LICE_pixel_chan *)bmp->getBits();
  85   int rowspan = bmp->getRowSpan()*4;
  86   if (bmp->isFlipped())
  87   {
  88     rd += rowspan*(bmp->getHeight()-1);
  89     rowspan=-rowspan;
  90   }
  91   while (cinfo.next_scanline < cinfo.image_height)
  92   {
  93     unsigned char *outp=buf;
  94     LICE_pixel_chan *rdp = rd;
  95     int x=cinfo.image_width;
  96     while(x--)
  97     {
  98       outp[0] = rdp[LICE_PIXEL_R];
  99       outp[1] = rdp[LICE_PIXEL_G];
 100       outp[2] = rdp[LICE_PIXEL_B];
 101       outp+=3;
 102       rdp+=4;
 103     }
 104     jpeg_write_scanlines(&cinfo, &buf, 1);
 105
 106     rd+=rowspan;
 107   }
 108   free(buf);
 109   buf=0;
 110
 111   jpeg_finish_compress(&cinfo);
 112
 113   if (fp) fclose(fp);
 114   fp=0;
 115
 116   jpeg_destroy_compress(&cinfo);
 117
 118   return true;
 119 }