#include "mjpeg.h"
#include "ff.h"
#include "lcd_rgb.h"
#include "mymem.h"
//////////////////////////////////////////////////////////////////////////////////
// 本程序只供学习使用，未经作者许可，不得用于其它任何用途
// ALIENTEK STM32F407开发板
// MJPEG视频处理 代码
// 正点原子@ALIENTEK
// 技术论坛:www.openedv.com
// 创建日期:2014/7/20
// 版本：V1.0
// 版权所有，盗版必究。
// Copyright(C) 广州市星翼电子科技有限公司 2009-2019
// All rights reserved
//*******************************************************************************
// 修改信息
// 无
//////////////////////////////////////////////////////////////////////////////////

struct jpeg_decompress_struct *cinfo;
struct my_error_mgr *jerr;
u8 *jpegbuf;          // jpeg数据缓存指针
u32 jbufsize;         // jpeg buf大小
u16 imgoffx, imgoffy; // 图像在x,y方向的偏移量

////////////////////////////////////////////////////////////////////////////////
// 简单快速的内存分配,以提高速度
#define MJPEG_MAX_MALLOC_SIZE 38 * 1024 // 最大可以分配38K字节

u8 *jmembuf; // mjpeg解码的 内存池
u32 jmempos; // 内存池指针

// mjpeg申请内存
void *mjpeg_malloc(u32 num) {
  u32 curpos = jmempos; // 此次分配的起始地址
  jmempos += num;       // 下一次分配的起始地址
  if (jmempos > MJPEG_MAX_MALLOC_SIZE) {
    printf("mem error:%d,%d", curpos, num);
  }
  return (void *)&jmembuf[curpos]; // 返回申请到的内存首地址
}
////////////////////////////////////////////////////////////////////////////////
// 错误退出
static void my_error_exit(j_common_ptr cinfo) {
  my_error_ptr myerr = (my_error_ptr)cinfo->err;
  (*cinfo->err->output_message)(cinfo);
  longjmp(myerr->setjmp_buffer, 1);
}

METHODDEF(void)
my_emit_message(j_common_ptr cinfo, int msg_level) {
  my_error_ptr myerr = (my_error_ptr)cinfo->err;
  if (msg_level < 0) {
    printf("emit msg:%d\r\n", msg_level);
    longjmp(myerr->setjmp_buffer, 1);
  }
}

// 初始化资源,不执行任何操作
static void init_source(j_decompress_ptr cinfo) {
  // 不需要做任何事情.
  return;
}
// 填充输入缓冲区,一次性读取整帧数据
static boolean fill_input_buffer(j_decompress_ptr cinfo) {
  if (jbufsize == 0) // 结束了
  {
    // printf("jd read off\r\n");
    // 填充结束符
    jpegbuf[0] = (u8)0xFF;
    jpegbuf[1] = (u8)JPEG_EOI;
    cinfo->src->next_input_byte = jpegbuf;
    cinfo->src->bytes_in_buffer = 2;
  } else {
    cinfo->src->next_input_byte = jpegbuf;
    cinfo->src->bytes_in_buffer = jbufsize;
    jbufsize -= jbufsize;
  }
  return TRUE;
}
// 在文件里面,跳过num_bytes个数据
static void skip_input_data(j_decompress_ptr cinfo, long num_bytes) {
  /* Just a dumb implementation for now.  Could use fseek() except
   * it doesn't work on pipes.  Not clear that being smart is worth
   * any trouble anyway --- large skips are infrequent.
   */
  if (num_bytes > 0) {
    while (num_bytes > (long)cinfo->src->bytes_in_buffer) {
      num_bytes -= (long)cinfo->src->bytes_in_buffer;
      (void)cinfo->src->fill_input_buffer(cinfo);
      /* note we assume that fill_input_buffer will never
       * return FALSE, so suspension need not be handled.
       */
    }
    cinfo->src->next_input_byte += (size_t)num_bytes;
    cinfo->src->bytes_in_buffer -= (size_t)num_bytes;
  }
}
// 在解码结束后,被jpeg_finish_decompress函数调用
static void term_source(j_decompress_ptr cinfo) {
  // 不做任何处理
  return;
}
// 初始化jpeg解码数据源
static void jpeg_filerw_src_init(j_decompress_ptr cinfo) {
  if (cinfo->src == NULL) /* first time for this JPEG object? */
  {
    cinfo->src = (struct jpeg_source_mgr *)(*cinfo->mem->alloc_small)(
        (j_common_ptr)cinfo, JPOOL_PERMANENT, sizeof(struct jpeg_source_mgr));
  }
  cinfo->src->init_source = init_source;
  cinfo->src->fill_input_buffer = fill_input_buffer;
  cinfo->src->skip_input_data = skip_input_data;
  cinfo->src->resync_to_restart =
      jpeg_resync_to_restart; /* use default method */
  cinfo->src->term_source = term_source;
  cinfo->src->bytes_in_buffer = 0; /* forces fill_input_buffer on first read */
  cinfo->src->next_input_byte = NULL; /* until buffer loaded */
}

// mjpeg 解码初始化
// offx,offy:x,y方向的偏移
// 返回值:0,成功;
//        1,失败
u8 mjpegdec_init(u16 offx, u16 offy) {
  cinfo = mymalloc(sizeof(struct jpeg_decompress_struct));
  jerr = mymalloc(sizeof(struct my_error_mgr));
  // 分配sram区的内存以提高解码速度--2020.6.2
  jmembuf = mymalloc_fast(MJPEG_MAX_MALLOC_SIZE); // MJPEG解码内存池申请
  if (cinfo == 0 || jerr == 0 || jmembuf == 0) {
    mjpegdec_free();
    return 1;
  }
  // 保存图像在x,y方向的偏移量
  imgoffx = offx;
  imgoffy = offy;
  return 0;
}
// mjpeg结束,释放内存
void mjpegdec_free(void) {
  myfree(cinfo);
  myfree(jerr);
  myfree(jmembuf);
}

// 解码一副JPEG图片
// buf:jpeg数据流数组
// bsize:数组大小
// 返回值:0,成功
//     其他,错误
u8 mjpegdec_decode(u8 *buf, u32 bsize) {
  JSAMPARRAY buffer;
  if (bsize == 0)
    return 1;
  jpegbuf = buf;
  jbufsize = bsize;
  jmempos = 0; // MJEPG解码,重新从0开始分配内存

  cinfo->err = jpeg_std_error(&jerr->pub);
  jerr->pub.error_exit = my_error_exit;
  jerr->pub.emit_message = my_emit_message;
  // if(bsize>20*1024)printf("s:%d\r\n",bsize);
  if (setjmp(jerr->setjmp_buffer)) // 错误处理
  {
    jpeg_abort_decompress(cinfo);
    jpeg_destroy_decompress(cinfo);
    return 2;
  }
  jpeg_create_decompress(cinfo);
  jpeg_filerw_src_init(cinfo);
  jpeg_read_header(cinfo, TRUE);
  cinfo->dct_method = JDCT_IFAST;
  cinfo->do_fancy_upsampling = 0;
  jpeg_start_decompress(cinfo);
  extern void jdmerge_setlcdaddr(unsigned short *addr);
  unsigned short *lcd_addr = (unsigned short *)LCD_GetDrawAddr();
  //	lcd_addr+=LCD_GetLcdSizeX()*LCD_GetLcdSizeY()-1-(imgoffx+imgoffy*LCD_GetLcdSizeX());
  jdmerge_setlcdaddr(lcd_addr); // 设置显示位置
  while (cinfo->output_scanline < cinfo->output_height) {
    jpeg_read_scanlines(cinfo, buffer, 1);
  }
  jpeg_finish_decompress(cinfo);
  jpeg_destroy_decompress(cinfo);
  return 0;
}