mirror of
https://github.com/STMicroelectronics/STM32CubeF4.git
synced 2025-05-02 22:17:06 +08:00
103 lines
3.7 KiB
C
103 lines
3.7 KiB
C
/**
|
|
******************************************************************************
|
|
* @file LibJPEG/LibJPEG_Encoding/Src/encode.c
|
|
* @author MCD Application Team
|
|
* @brief This file contain the compress method.
|
|
******************************************************************************
|
|
* @attention
|
|
*
|
|
* Copyright (c) 2017 STMicroelectronics.
|
|
* All rights reserved.
|
|
*
|
|
* This software is licensed under terms that can be found in the LICENSE file
|
|
* in the root directory of this software component.
|
|
* If no LICENSE file comes with this software, it is provided AS-IS.
|
|
*
|
|
******************************************************************************
|
|
*/
|
|
/* Includes ------------------------------------------------------------------*/
|
|
#include "encode.h"
|
|
|
|
/* Private typedef -----------------------------------------------------------*/
|
|
/* This struct contains the JPEG compression parameters */
|
|
static struct jpeg_compress_struct cinfo;
|
|
/* This struct represents a JPEG error handler */
|
|
static struct jpeg_error_mgr jerr;
|
|
|
|
/* Private define ------------------------------------------------------------*/
|
|
/* Private macro -------------------------------------------------------------*/
|
|
/* Private variables ---------------------------------------------------------*/
|
|
/* Private function prototypes -----------------------------------------------*/
|
|
/* Private functions ---------------------------------------------------------*/
|
|
extern RGB_typedef *RGB_matrix;
|
|
|
|
/**
|
|
* @brief Jpeg Encode
|
|
* @param file: pointer to the bmp file
|
|
* @param file1: pointer to the jpg file
|
|
* @param width: image width
|
|
* @param height: image height
|
|
* @param image_quality: image quality
|
|
* @param buff: pointer to the image line
|
|
* @retval None
|
|
*/
|
|
void jpeg_encode(JFILE *file, JFILE *file1, uint32_t width, uint32_t height, uint32_t image_quality, uint8_t * buff)
|
|
{
|
|
|
|
/* Encode BMP Image to JPEG */
|
|
JSAMPROW row_pointer; /* Pointer to a single row */
|
|
uint32_t bytesread;
|
|
uint32_t index;
|
|
|
|
/* Step 1: allocate and initialize JPEG compression object */
|
|
/* Set up the error handler */
|
|
cinfo.err = jpeg_std_error(&jerr);
|
|
|
|
/* Initialize the JPEG compression object */
|
|
jpeg_create_compress(&cinfo);
|
|
|
|
/* Step 2: specify data destination */
|
|
jpeg_stdio_dest(&cinfo, file1);
|
|
|
|
/* Step 3: set parameters for compression */
|
|
cinfo.image_width = width;
|
|
cinfo.image_height = height;
|
|
cinfo.input_components = 3;
|
|
cinfo.in_color_space = JCS_RGB;
|
|
|
|
/* Set default compression parameters */
|
|
jpeg_set_defaults(&cinfo);
|
|
|
|
cinfo.dct_method = JDCT_FLOAT;
|
|
|
|
jpeg_set_quality(&cinfo, image_quality, TRUE);
|
|
|
|
/* Step 4: start compressor */
|
|
jpeg_start_compress(&cinfo, TRUE);
|
|
|
|
/* Get bitmap data address offset */
|
|
f_read(file, buff, 14, (UINT*)&bytesread);
|
|
index = *(__IO uint16_t *) (buff + 10);
|
|
index |= (*(__IO uint16_t *) (buff + 12)) << 16;
|
|
|
|
while (cinfo.next_scanline < cinfo.image_height)
|
|
{
|
|
/* In this application, the input file is a BMP, which first encodes the bottom of the picture */
|
|
/* JPEG encodes the highest part of the picture first. We need to read the lines upside down */
|
|
/* Move the read pointer to 'last line of the picture - next_scanline' */
|
|
f_lseek(file, ((cinfo.image_height-1-cinfo.next_scanline)*width*3)+index);
|
|
if(f_read(file, buff, width*3, (UINT*)&bytesread) == FR_OK)
|
|
{
|
|
row_pointer = (JSAMPROW)buff;
|
|
jpeg_write_scanlines(&cinfo, &row_pointer, 1);
|
|
}
|
|
}
|
|
|
|
/* Step 5: finish compression */
|
|
jpeg_finish_compress(&cinfo);
|
|
|
|
/* Step 6: release JPEG compression object */
|
|
jpeg_destroy_compress(&cinfo);
|
|
|
|
}
|