acid-drop/lib/GFX_Library_for_Arduino-1.3.5/examples/WiFiPhotoFrame/JpegFunc.h

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2024-05-23 22:42:03 +00:00
/*******************************************************************************
* JPEGDEC related function
*
* Dependent libraries:
* JPEGDEC: https://github.com/bitbank2/JPEGDEC.git
******************************************************************************/
#ifndef _JPEGFUNC_H_
#define _JPEGFUNC_H_
#include <JPEGDEC.h>
static JPEGDEC _jpeg;
static int _x, _y, _x_bound, _y_bound;
static void jpegCloseHttpStream(void *pHandle)
{
// printf("jpegCloseHttpStream\n");
// WiFiClient *http_stream = (WiFiClient *)pHandle;
// do nothing
}
static int32_t readStream(WiFiClient *http_stream, uint8_t *pBuf, int32_t iLen)
{
uint8_t wait = 0;
size_t a = http_stream->available();
size_t r = 0;
while ((r < iLen) && (wait < 10))
{
if (a)
{
wait = 0; // reset wait count once available
r += http_stream->readBytes(pBuf + r, iLen - r);
// printf("1st byte: %d, 2nd byte: %d, last byte: %d, iLen: %d, r: %d, wait: %d\n", pBuf[0], pBuf[1], pBuf[r - 1], iLen, r, wait);
}
else
{
delay(100);
wait++;
}
a = http_stream->available();
}
return r;
}
static int32_t jpegReadHttpStream(JPEGFILE *pFile, uint8_t *pBuf, int32_t iLen)
{
// printf("jpegReadHttpStream, iLen: %d\n", iLen);
WiFiClient *http_stream = (WiFiClient *)pFile->fHandle;
return readStream(http_stream, pBuf, iLen);
}
static int32_t jpegSeekHttpStream(JPEGFILE *pFile, int32_t iPosition)
{
// printf("jpegSeekHttpStream, pFile->iPos: %d, iPosition: %d\n", pFile->iPos, iPosition);
WiFiClient *http_stream = (WiFiClient *)pFile->fHandle;
http_stream->readBytes((uint8_t *)nullptr, iPosition - pFile->iPos);
return iPosition;
}
static int jpegOpenHttpStreamWithBuffer(WiFiClient *http_stream, uint8_t *buf, int32_t dataSize, JPEG_DRAW_CALLBACK *jpegDrawCallback)
{
int32_t r = readStream(http_stream, buf, dataSize);
if (r != dataSize)
{
return 0;
}
return _jpeg.openRAM(buf, dataSize, jpegDrawCallback);
}
static int jpegOpenHttpStream(WiFiClient *http_stream, int32_t dataSize, JPEG_DRAW_CALLBACK *jpegDrawCallback)
{
return _jpeg.open(http_stream, dataSize, jpegCloseHttpStream, jpegReadHttpStream, jpegSeekHttpStream, jpegDrawCallback);
}
static int jpegDraw(bool useBigEndian,
int x, int y, int widthLimit, int heightLimit)
{
_x = x;
_y = y;
_x_bound = _x + widthLimit - 1;
_y_bound = _y + heightLimit - 1;
// scale to fit height
int _scale;
int iMaxMCUs;
float ratio = (float)_jpeg.getHeight() / heightLimit;
if (ratio <= 1)
{
_scale = 0;
iMaxMCUs = widthLimit / 16;
}
else if (ratio <= 2)
{
_scale = JPEG_SCALE_HALF;
iMaxMCUs = widthLimit / 8;
}
else if (ratio <= 4)
{
_scale = JPEG_SCALE_QUARTER;
iMaxMCUs = widthLimit / 4;
}
else
{
_scale = JPEG_SCALE_EIGHTH;
iMaxMCUs = widthLimit / 2;
}
_jpeg.setMaxOutputSize(iMaxMCUs);
if (useBigEndian)
{
_jpeg.setPixelType(RGB565_BIG_ENDIAN);
}
int decode_result = _jpeg.decode(x, y, _scale);
_jpeg.close();
return decode_result;
}
#endif // _JPEGFUNC_H_