mirror of
https://github.com/STMicroelectronics/STM32CubeF4.git
synced 2025-05-02 22:17:06 +08:00
85 lines
2.8 KiB
C
85 lines
2.8 KiB
C
/**
|
|
******************************************************************************
|
|
* @file LibJPEG/LibJPEG_Encoding/Src/decode.c
|
|
* @author MCD Application Team
|
|
* @brief This file contain the decompress 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 "decode.h"
|
|
|
|
/* Private typedef -----------------------------------------------------------*/
|
|
/* This struct contains the JPEG decompression parameters */
|
|
struct jpeg_decompress_struct cinfo;
|
|
/* This struct represents a JPEG error handler */
|
|
struct jpeg_error_mgr jerr;
|
|
|
|
/* Private define ------------------------------------------------------------*/
|
|
/* Private macro -------------------------------------------------------------*/
|
|
/* Private variables ---------------------------------------------------------*/
|
|
/* Private function prototypes -----------------------------------------------*/
|
|
/* Private functions ---------------------------------------------------------*/
|
|
|
|
/**
|
|
* @brief Jpeg Decode
|
|
* @param callback: line decoding callback
|
|
* @param file1: pointer to the jpg file
|
|
* @param width: image width
|
|
* @param buff: pointer to the image line
|
|
* @retval None
|
|
*/
|
|
void jpeg_decode(JFILE *file, uint32_t width, uint8_t * buff, uint8_t (*callback)(uint8_t*, uint32_t))
|
|
{
|
|
|
|
/* Decode JPEG Image */
|
|
JSAMPROW buffer[2] = {0}; /* Output row buffer */
|
|
uint32_t row_stride = 0; /* physical row width in image buffer */
|
|
|
|
buffer[0] = buff;
|
|
|
|
/* Step 1: allocate and initialize JPEG decompression object */
|
|
cinfo.err = jpeg_std_error(&jerr);
|
|
|
|
/* Initialize the JPEG decompression object */
|
|
jpeg_create_decompress(&cinfo);
|
|
|
|
jpeg_stdio_src (&cinfo, file);
|
|
|
|
/* Step 3: read image parameters with jpeg_read_header() */
|
|
jpeg_read_header(&cinfo, TRUE);
|
|
|
|
/* Step 4: set parameters for decompression */
|
|
cinfo.dct_method = JDCT_FLOAT;
|
|
|
|
/* Step 5: start decompressor */
|
|
jpeg_start_decompress(&cinfo);
|
|
|
|
row_stride = width * 3;
|
|
while (cinfo.output_scanline < cinfo.output_height)
|
|
{
|
|
(void) jpeg_read_scanlines(&cinfo, buffer, 1);
|
|
|
|
if (callback(buffer[0], row_stride) != 0)
|
|
{
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Step 6: Finish decompression */
|
|
jpeg_finish_decompress(&cinfo);
|
|
|
|
/* Step 7: Release JPEG decompression object */
|
|
jpeg_destroy_decompress(&cinfo);
|
|
|
|
}
|