added missing 8-bit routines and fixed example

bitbank2 · Aug 28, 2020 · 8595e62 · 8595e62
1 parent 89110a1
commit 8595e62
Show file tree

Hide file tree

Showing 2 changed files with 198 additions and 23 deletions.
diff --git a/examples/ILI9431_t3_slideshow/ILI9431_t3_slideshow.ino b/examples/ILI9431_t3_slideshow/ILI9431_t3_slideshow.ino
@@ -40,7 +40,7 @@ void setup() {
 // Functions to access a file on the SD card
 File myfile;
 
-void * myOpen(char *filename, int32_t *size) {
+void * myOpen(const char *filename, int32_t *size) {
  myfile = SD.open(filename);
  *size = myfile.size();
  return &myfile;
@@ -80,7 +80,7 @@ void loop() {
  Serial.println(name);
  tft.print("File: ");
  tft.println(name);
- jpeg.open((char *)name, myOpen, myClose, myRead, mySeek, JPEGDraw);
+ jpeg.open((const char *)name, myOpen, myClose, myRead, mySeek, JPEGDraw);
  jpeg.decode(0, 0, 0);
  jpeg.close();
  filecount = filecount + 1;

diff --git a/src/jpeg.c b/src/jpeg.c
@@ -1981,34 +1981,209 @@ static void JPEGPutMCU8BitGray(JPEGIMAGE *pJPEG, int x, int iPitch)
 
  pDest = (uint8_t *)&pJPEG->usPixels[x/2];
 
- if (pJPEG->iOptions & JPEG_SCALE_HALF) // special handling of 1/2 size (pixel averaging)
+ if (pJPEG->ucSubSample <= 0x11) // single Y 
  {
- int pix;
- for (i=0; i<4; i++)
+ if (pJPEG->iOptions & JPEG_SCALE_HALF) // special handling of 1/2 size (pixel averaging)
  {
- for (j=0; j<4; j++)
+ int pix;
+ for (i=0; i<4; i++)
  {
- pix = (pSrc[0] + pSrc[1] + pSrc[8] + pSrc[9] + 2) >> 2; // average 2x2 block
- pDest[i] = (uint8_t)pix;
- pSrc += 2;
+ for (j=0; j<4; j++)
+ {
+ pix = (pSrc[0] + pSrc[1] + pSrc[8] + pSrc[9] + 2) >> 2; // average 2x2 block
+ pDest[i] = (uint8_t)pix;
+ pSrc += 2;
+ }
+ pSrc += 8; // skip extra line
+ pDest += iPitch;
  }
- pSrc += 8; // skip extra line
- pDest += iPitch;
+ return;
+ }
+ xcount = ycount = 8; // debug
+ if (pJPEG->iOptions & JPEG_SCALE_QUARTER)
+ xcount = ycount = 2;
+ else if (pJPEG->iOptions & JPEG_SCALE_EIGHTH)
+ xcount = ycount = 1;
+ for (i=0; i<ycount; i++) // do up to 8 rows
+ {
+ for (j=0; j<xcount; j++)
+ *pDest++ = *pSrc++;
+ pDest -= xcount;
+ pDest += iPitch; // next line
  }
  return;
- }
- xcount = ycount = 8; // debug
- if (pJPEG->iOptions & JPEG_SCALE_QUARTER)
- xcount = ycount = 2;
- else if (pJPEG->iOptions & JPEG_SCALE_EIGHTH)
- xcount = ycount = 1;
- for (i=0; i<ycount; i++) // do up to 8 rows
+ } // single Y source
+ if (pJPEG->ucSubSample == 0x21) // stacked horizontally
  {
- for (j=0; j<xcount; j++)
- *pDest++ = *pSrc++;
- pDest -= xcount;
- pDest += iPitch; // next line
- }
+ if (pJPEG->iOptions & JPEG_SCALE_EIGHTH)
+ {
+ // only 2 pixels emitted
+ pDest[0] = pSrc[0];
+ pDest[1] = pSrc[128];
+ return;
+ } /* 1/8 */
+ if (pJPEG->iOptions & JPEG_SCALE_HALF)
+ {
+ for (i=0; i<4; i++)
+ {
+ for (j=0; j<4; j++)
+ {
+ int pix;
+ pix = (pSrc[j*2] + pSrc[j*2+1] + pSrc[j*2 + 8] + pSrc[j*2 + 9] + 3) >> 2;
+ pDest[j] = (uint8_t)pix;
+ pix = (pSrc[j*2 + 128] + pSrc[j*2+129] + pSrc[j*2 + 136] + pSrc[j*2 + 137] + 3) >> 2;
+ pDest[j+4] = (uint8_t)pix;
+ }
+ pSrc += 16;
+ pDest += iPitch;
+ }
+ return;
+ }
+ if (pJPEG->iOptions & JPEG_SCALE_QUARTER)
+ {
+ // each MCU contributes a 2x2 block
+ pDest[0] = pSrc[0]; // Y0
+ pDest[1] = pSrc[1];
+ pDest[iPitch] = pSrc[2];
+ pDest[iPitch+1] = pSrc[3];
+
+ pDest[2] = pSrc[128]; // Y`
+ pDest[3] = pSrc[129];
+ pDest[iPitch+2] = pSrc[130];
+ pDest[iPitch+3] = pSrc[131];
+ return;
+ }
+ for (i=0; i<8; i++)
+ {
+ for (j=0; j<8; j++)
+ {
+ pDest[j] = pSrc[j];
+ pDest[j+8] = pSrc[128 + j];
+ }
+ pSrc += 8;
+ pDest += iPitch;
+ }
+ } // 0x21
+ if (pJPEG->ucSubSample == 0x12) // stacked vertically
+ {
+ if (pJPEG->iOptions & JPEG_SCALE_EIGHTH)
+ {
+ // only 2 pixels emitted
+ pDest[0] = pSrc[0];
+ pDest[iPitch] = pSrc[128];
+ return;
+ } /* 1/8 */
+ if (pJPEG->iOptions & JPEG_SCALE_HALF)
+ {
+ for (i=0; i<4; i++)
+ {
+ for (j=0; j<4; j++)
+ {
+ int pix;
+ pix = (pSrc[j*2] + pSrc[j*2+1] + pSrc[j*2 + 8] + pSrc[j*2 + 9] + 3) >> 2;
+ pDest[j] = (uint8_t)pix;
+ pix = (pSrc[j*2 + 128] + pSrc[j*2+129] + pSrc[j*2 + 136] + pSrc[j*2 + 137] + 3) >> 2;
+ pDest[4*iPitch+j] = (uint8_t)pix;
+ }
+ pSrc += 16;
+ pDest += iPitch;
+ }
+ return;
+ }
+ if (pJPEG->iOptions & JPEG_SCALE_QUARTER)
+ {
+ // each MCU contributes a 2x2 block
+ pDest[0] = pSrc[0]; // Y0
+ pDest[1] = pSrc[1];
+ pDest[iPitch] = pSrc[2];
+ pDest[iPitch+1] = pSrc[3];
+
+ pDest[iPitch*2] = pSrc[128]; // Y`
+ pDest[iPitch*2+1] = pSrc[129];
+ pDest[iPitch*3] = pSrc[130];
+ pDest[iPitch*3+1] = pSrc[131];
+ return;
+ }
+ for (i=0; i<8; i++)
+ {
+ for (j=0; j<8; j++)
+ {
+ pDest[j] = pSrc[j];
+ pDest[8*iPitch + j] = pSrc[128 + j];
+ }
+ pSrc += 8;
+ pDest += iPitch;
+ }
+ } // 0x12
+ if (pJPEG->ucSubSample == 0x22)
+ {
+ if (pJPEG->iOptions & JPEG_SCALE_EIGHTH)
+ {
+ // each MCU contributes 1 pixel
+ pDest[0] = pSrc[0]; // Y0
+ pDest[1] = pSrc[128]; // Y1
+ pDest[iPitch] = pSrc[256]; // Y2
+ pDest[iPitch + 1] = pSrc[384]; // Y3
+ return;
+ }
+ if (pJPEG->iOptions & JPEG_SCALE_QUARTER)
+ {
+ // each MCU contributes 2x2 pixels
+ pDest[0] = pSrc[0]; // Y0
+ pDest[1] = pSrc[1];
+ pDest[iPitch] = pSrc[2];
+ pDest[iPitch+1] = pSrc[3];
+
+ pDest[2] = pSrc[128]; // Y1
+ pDest[3] = pSrc[129];
+ pDest[iPitch+2] = pSrc[130];
+ pDest[iPitch+3] = pSrc[131];
+
+ pDest[iPitch*2] = pSrc[256]; // Y2
+ pDest[iPitch*2+1] = pSrc[257];
+ pDest[iPitch*3] = pSrc[258];
+ pDest[iPitch*3+1] = pSrc[259];
+
+ pDest[iPitch*2+2] = pSrc[384]; // Y3
+ pDest[iPitch*2+3] = pSrc[385];
+ pDest[iPitch*3+2] = pSrc[386];
+ pDest[iPitch*3+3] = pSrc[387];
+ return;
+ }
+ if (pJPEG->iOptions & JPEG_SCALE_HALF)
+ {
+ for (i=0; i<4; i++)
+ {
+ for (j=0; j<4; j++)
+ {
+ int pix;
+ pix = (pSrc[j*2] + pSrc[j*2+1] + pSrc[j*2 + 8] + pSrc[j*2 + 9] + 3) >> 2;
+ pDest[j] = (uint8_t)pix; // Y0
+ pix = (pSrc[j*2+128] + pSrc[j*2+129] + pSrc[j*2 + 136] + pSrc[j*2 + 137] + 3) >> 2;
+ pDest[j+4] = (uint8_t)pix; // Y1
+ pix = (pSrc[j*2+256] + pSrc[j*2+257] + pSrc[j*2 + 264] + pSrc[j*2 + 265] + 3) >> 2;
+ pDest[iPitch*4 + j] = (uint8_t)pix; // Y2
+ pix = (pSrc[j*2+384] + pSrc[j*2+385] + pSrc[j*2 + 392] + pSrc[j*2 + 393] + 3) >> 2;
+ pDest[iPitch*4 + j + 4] = (uint8_t)pix; // Y3
+ }
+ pSrc += 16;
+ pDest += iPitch;
+ }
+ return;
+ }
+ for (i=0; i<8; i++)
+ {
+ for (j=0; j<8; j++)
+ {
+ pDest[j] = pSrc[j]; // Y0
+ pDest[j+8] = pSrc[j+128]; // Y1
+ pDest[iPitch*8 + j] = pSrc[j+256]; // Y2
+ pDest[iPitch*8 + j + 8] = pSrc[j + 384]; // Y3
+ }
+ pSrc += 8;
+ pDest += iPitch;
+ }
+ } // 0x22
 } /* JPEGMPutMCU8BitGray() */
 
 static void JPEGPutMCUGray(JPEGIMAGE *pJPEG, int x, int iPitch)