JPEG_DECODE_ERROR on a large epaper screen

[countrysideboy]

jpegdec_debug.zip
I use JPEGDEC to decode the jpeg file on a large 7 color e-ink screen(800x480), but I cannot show the whole and get a JPEG_DECODE_ERROR.
I try to add some debug code, and find the JPEGDecodeMCU function throw an error in the area of the code below.

 // get the DC component
    pucFast = &pJPEG->ucHuffDC[pJPEG->ucDCTable * DC_TABLE_SIZE];
    ulCode = (ulBits >> (REGISTER_WIDTH - 12 - ulBitOff)) & 0xfff; // get as lower 12 bits
    if (ulCode >= 0xf80) // it's a long code
        ulCode = (ulCode & 0xff); // point to long table and trim to 7-bits + 0x80 offset into long table
    else
        ulCode >>= 6; // it's a short code, use first 6 bits only
    ucHuff = pucFast[ulCode];
    cCoeff = (signed char)pucFast[ulCode+512]; // get pre-calculated extra bits for "small" values
    if (ucHuff == 0) {// invalid code
		Serial.println("invalid code1");//【Where the error occurred】
        return -1;
	}

The same code works well with the 2.9 inch black and white epaper.The difference of the bw and 7 color screen maybe the display buffer(800x480 use more ram).Esp32 and rp2040 get the same result.
I try to use another lib, TJpg_Decoder, which can decode without error on my 7 clolor screen.

[countrysideboy]

I tried to submit the same problem in that issue, and I'm sorry for sending the code so late.

[countrysideboy]

The batman.jpg is also throw the decode error on the 7 clolor screen of gxepd2 driver.

[countrysideboy]

Read the jpg file from the flash or sd card, get the same result.

[countrysideboy]

Here is the code, and the doraemon.h is in the zip file.

#define PIN_EPD_CS 33  ////SPI1 CSn
#define PIN_EPD_RST 26
#define PIN_EPD_DC 27  //SIP1 RX
#define PIN_EPD_BUSY 25
#define PIN_EPD_CLK 13   //SPI1 SCK
#define PIN_EPD_MOSI 14  //SIP1 TX
#define PIN_EPD_EN 32    // epd power control for my esp32s1 board

#include "JPEGDEC.h"
JPEGDEC jpeg;
#include "doraemon.h"

#include <SPI.h>
SPIClass SPIEP(HSPI);
#define SPI_PORT_EPD SPIEP

#include <GxEPD2_BW.h>
#include <GxEPD2_7C.h>
#define GxEPD2_DISPLAY_CLASS GxEPD2_7C
#define GxEPD2_DRIVER_CLASS GxEPD2_730c_ACeP_730

// somehow there should be an easier way to do this
#define GxEPD2_BW_IS_GxEPD2_BW true
#define GxEPD2_3C_IS_GxEPD2_3C true
#define GxEPD2_7C_IS_GxEPD2_7C true
#define GxEPD2_1248_IS_GxEPD2_1248 true
#define GxEPD2_1248c_IS_GxEPD2_1248c true
#define IS_GxEPD(c, x) (c##x)
#define IS_GxEPD2_BW(x) IS_GxEPD(GxEPD2_BW_IS_, x)
#define IS_GxEPD2_3C(x) IS_GxEPD(GxEPD2_3C_IS_, x)
#define IS_GxEPD2_7C(x) IS_GxEPD(GxEPD2_7C_IS_, x)
#define IS_GxEPD2_1248(x) IS_GxEPD(GxEPD2_1248_IS_, x)
#define IS_GxEPD2_1248c(x) IS_GxEPD(GxEPD2_1248c_IS_, x)

#define MAX_DISPLAY_BUFFER_SIZE 65536ul  // e.g. 64k

#if IS_GxEPD2_BW(GxEPD2_DISPLAY_CLASS)
#define MAX_HEIGHT(EPD) (EPD::HEIGHT <= MAX_DISPLAY_BUFFER_SIZE / (EPD::WIDTH / 8) ? EPD::HEIGHT : MAX_DISPLAY_BUFFER_SIZE / (EPD::WIDTH / 8))
#elif IS_GxEPD2_3C(GxEPD2_DISPLAY_CLASS)
#define MAX_HEIGHT(EPD) (EPD::HEIGHT <= (MAX_DISPLAY_BUFFER_SIZE / 2) / (EPD::WIDTH / 8) ? EPD::HEIGHT : (MAX_DISPLAY_BUFFER_SIZE / 2) / (EPD::WIDTH / 8))
#elif IS_GxEPD2_7C(GxEPD2_DISPLAY_CLASS)
#define MAX_HEIGHT(EPD) (EPD::HEIGHT <= (MAX_DISPLAY_BUFFER_SIZE) / (EPD::WIDTH / 2) ? EPD::HEIGHT : (MAX_DISPLAY_BUFFER_SIZE) / (EPD::WIDTH / 2))
#endif

GxEPD2_DISPLAY_CLASS<GxEPD2_DRIVER_CLASS, MAX_HEIGHT(GxEPD2_DRIVER_CLASS)> display(GxEPD2_DRIVER_CLASS(/*CS*/ PIN_EPD_CS, /*DC*/ PIN_EPD_DC, /*RST*/ PIN_EPD_RST, /*BUSY*/ PIN_EPD_BUSY));

void convert_rgb_565_to_rgb(uint16_t rgb565, uint16_t *r, uint16_t *g, uint16_t *b) {
  *r = (rgb565 & 0xF800) >> 8;
  *g = (rgb565 & 0x07E0) >> 3;
  *b = (rgb565 & 0x001F) << 3;
}

int JPEGDraw_callback(JPEGDRAW *pDraw);
int JPEGDraw_callback(JPEGDRAW *pDraw) {
yield();
  bool _with_color = true;
  uint16_t red, green, blue;
  bool whitish = false;
  bool colored = false;
  uint16_t color = GxEPD_WHITE;
  int x = pDraw->x;
  int y = pDraw->y;
  int w = pDraw->iWidth;
  int h = pDraw->iHeight;

  for (int16_t i = 0; i < w; i++) {
    for (int16_t j = 0; j < h; j++) {
      convert_rgb_565_to_rgb(pDraw->pPixels[i + j * w], &red, &green, &blue);
      whitish = _with_color ? ((red > 0x80) && (green > 0x80) && (blue > 0x80)) : ((red + green + blue) > 3 * 0x80);  // whitish
      colored = (red > 0xF0) || ((green > 0xF0) && (blue > 0xF0));
      color = ((red & 0xF8) << 8) | ((green & 0xFC) << 3) | ((blue & 0xF8) >> 3);
      if (_with_color) {
        // keep color
      } else if (whitish) {
        color = GxEPD_WHITE;
      } else if (colored && _with_color) {
        color = GxEPD_COLORED;
      } else {
        color = GxEPD_BLACK;
      }
      display.drawPixel((x + i), (y + j) , color);
    }  // for j
  }    // for i
  return 1;
} /* JPEGDraw() */

void setup() {
  Serial.begin(115200);
	
  pinMode(PIN_EPD_EN, OUTPUT);
  digitalWrite(PIN_EPD_EN, HIGH);  // turn on the screen power

  SPI_PORT_EPD.end();  // release standard SPI pins
  SPI_PORT_EPD.begin(PIN_EPD_CLK, PIN_EPD_DC, PIN_EPD_MOSI, PIN_EPD_CS);
  pinMode(PIN_EPD_CS, OUTPUT);

  display.epd2.selectSPI(SPI_PORT_EPD, SPISettings(4000000, MSBFIRST, SPI_MODE0));
  display.init(115200, true, 2, false);
  display.setRotation(0);

  if (jpeg.openFLASH((uint8_t *)doraemon, sizeof(doraemon), JPEGDraw_callback)) {
    display.firstPage();
    do {
      jpeg.decode(0, 0, 0);
    } while (display.nextPage());
  }

} /* setup() */

void loop() {
} /* loop() */