Diff: picojpeg/jpegutil.c

Revision:

0:c546b51ecf0b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/picojpeg/jpegutil.c	Tue Oct 11 01:24:18 2011 +0000
@@ -0,0 +1,107 @@
+#include "jpegutil.h"
+
+FILE *jpegfile;
+int jpeg_filesize = 0;
+int jpeg_filepos = 0;
+
+unsigned char pjpeg_need_bytes_callback(unsigned char* pBuf, unsigned char buf_size, unsigned char *pBytes_actually_read, void *pCallback_data)
+{
+   unsigned int n = min((unsigned int)(jpeg_filesize - jpeg_filepos), (unsigned int)buf_size);
+   if (n && (fread(pBuf, 1, n, jpegfile) != n))
+      return PJPG_STREAM_READ_ERROR;
+   *pBytes_actually_read = (unsigned char)(n);
+   jpeg_filepos += n;
+   return 0;
+}
+
+void ReadJPEGFromFile(const char *filename, NokiaLCD *lcd)
+{
+    pjpeg_image_info_t imageInfo;
+    jpegfile = fopen(filename,"rb");
+    fseek(jpegfile, 0, SEEK_END);
+    jpeg_filesize = ftell(jpegfile);
+    jpeg_filepos = 0;
+    fseek(jpegfile, 0, SEEK_SET);
+    int status = pjpeg_decode_init(&imageInfo, pjpeg_need_bytes_callback, NULL);
+   //const unsigned int row_pitch = imageInfo.m_width * imageInfo.m_comps;
+   int mcu_x = 0;
+   int mcu_y = 0;
+
+   for ( ; ; )
+   {
+      status = pjpeg_decode_mcu();
+
+      if (status)
+      {
+         if (status != PJPG_NO_MORE_BLOCKS)
+         {
+            //pc.printf("pjpeg_decode_mcu() failed with status %u\n", status);
+            fclose(jpegfile);
+            return;
+         }
+
+         break;
+      }
+
+      if (mcu_y >= imageInfo.m_MCUSPerCol)
+      {
+         fclose(jpegfile);
+         return;
+      }
+            
+      // Copy MCU's pixel blocks into the destination bitmap.
+
+      for (int y = 0; y < imageInfo.m_MCUHeight; y += 8)
+      {
+         const int by_limit = min(8, imageInfo.m_height - (mcu_y * imageInfo.m_MCUHeight + y));
+         for (int x = 0; x < imageInfo.m_MCUWidth; x += 8)
+         {
+
+            unsigned int src_ofs = (x * 8U) + (y * 16U);
+            const unsigned char *pSrcR = imageInfo.m_pMCUBufR + src_ofs;
+            const unsigned char *pSrcG = imageInfo.m_pMCUBufG + src_ofs;
+            const unsigned char *pSrcB = imageInfo.m_pMCUBufB + src_ofs;
+
+            const int bx_limit = min(8, imageInfo.m_width - (mcu_x * imageInfo.m_MCUWidth + x));
+                        
+            if (imageInfo.m_scanType == PJPG_GRAYSCALE)
+            {
+               for (int by = 0; by < by_limit; by++)
+               {
+                  for (int bx = 0; bx < bx_limit; bx++)
+                  {
+                      unsigned int color = ((*pSrcR++) << 16);   
+                      (*lcd).pixel(mcu_x*imageInfo.m_MCUWidth+x+bx,mcu_y*imageInfo.m_MCUHeight+y+by,color);
+                  }
+                  pSrcR += (8 - bx_limit);
+               }
+            }
+            else
+            {
+               for (int by = 0; by < by_limit; by++)
+               {
+                  for (int bx = 0; bx < bx_limit; bx++)
+                  {
+                     unsigned int color = ((*pSrcR++) << 16) | ((*pSrcG++) << 8) | (*pSrcB++);
+                     (*lcd).pixel((130-imageInfo.m_width)/2+mcu_x*imageInfo.m_MCUWidth+x+bx,(130-imageInfo.m_height)/2+mcu_y*imageInfo.m_MCUHeight+y+by,color);
+                  }
+
+                  pSrcR += (8 - bx_limit);
+                  pSrcG += (8 - bx_limit);
+                  pSrcB += (8 - bx_limit);
+
+               }
+            }
+         }
+      }
+
+      mcu_x++;
+      if (mcu_x == imageInfo.m_MCUSPerRow)
+      {
+         mcu_x = 0;
+         mcu_y++;
+      }
+   }
+      
+   fclose(jpegfile);
+}
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