jpeg.c

LCM module .9320 relevant information .320 X240

//=============================================================
// 文件名称：	jpeg_decoder.c
// 功能描述:	jpeg解码程序
// 维护记录:	2007-8-13	by liuxue created
//				2007.08.23	V1.0		by lijian <[e-mail]>
//=============================================================

#include "JPEG.h"
#include "MPEG4_Driver.h"
#include "BLNDMA.h"

//=============================================================
// 语法格式：	unsigned char *find_marker(unsigned char * jpg_ptr);
// 实现功能：	找jpeg的marker
// 参数：		jpg_ptr，指向jpeg数据的指针
// 返回值：		marker
//=============================================================
static unsigned char *find_marker(unsigned char * jpg_ptr)
{
	while(*jpg_ptr != 0xff)
	{
		jpg_ptr++;
	}
	
	return ++jpg_ptr;				// 返回marker
}


//=============================================================
// 语法格式：	unsigned int get_jpg_segment_length(unsigned char *jpg_ptr);
// 实现功能：	找当前marker栏的长度
// 参数：		jpg_ptr，指向jpeg数据的指针
// 返回值：		length，当前marker栏的长度，长度不包括marker，但包括length本身
//=============================================================

static unsigned int get_jpg_segment_length(unsigned char *jpg_ptr)
{
	unsigned int length;

	length = (*jpg_ptr << 8) + *(jpg_ptr + 1);
	
	return length;
}

//=============================================================
// 语法格式：	unsigned char *bypass_jpg_segment(unsigned char *jpg_ptr);
// 实现功能：	跳过当前marker栏数据
// 参数：		jpg_ptr，指向jpeg数据的指针
// 返回值：		jpr_ptr，指向下一个marker栏首
//=============================================================

static unsigned char *bypass_jpg_segment(unsigned char *jpg_ptr)
{
	unsigned int length;
	
	length = get_jpg_segment_length(jpg_ptr);
	jpg_ptr = jpg_ptr + length;
	
	return jpg_ptr;	
}

//=============================================================
// 语法格式：	void fill_quantize_sram(unsigned char *jpg_ptr);
// 实现功能：	向SPCE3200填充量化表
// 参数：		jpg_ptr，指向jpeg数据的指针
// 返回值：		无
//=============================================================

static void fill_quantize_sram(unsigned char *jpg_ptr)
{
	const unsigned int jpeg_natural_order[64] = {
												0,	1,	8,	16,	9,	2,	3,	10,
												17,	24,	32,	25,	18,	11,	4,	5,
												12,	19,	26,	33,	40,	48,	41,	34,
												27,	20,	13,	6,	7,	14,	21,	28,
												35,	42,	49,	56,	57,	50,	43,	36,
												29,	22,	15,	23,	30,	37,	44,	51,
												58,	59,	52,	45,	38,	31,	39,	46,
												53,	60,	61,	54,	47,	55,	62,	63
												};		// Zig-Zag变换
	unsigned int i;
	unsigned int length, counter;
	unsigned char qtable[64];
	unsigned char *pointer;
	unsigned int *ptr;
	
	length = get_jpg_segment_length(jpg_ptr);
	counter = 2;
	pointer = jpg_ptr + 2;
	
	*P_MPEG4_QTABLE_SRAM = C_MPEG4_QTABLESRAM_EN;		// enable CPU access Q Sram
	
	while(counter < length)
	{
		if((*pointer & 0x0f)== 0x00)
		{
			ptr = (unsigned int *)P_MPEG4_QTABLE1_START;// fill Y Q_table ，亮度
		}
		else
		{
			ptr = (unsigned int *)P_MPEG4_QTABLE2_START;// fill C Q_table chroma，色度
		}
		
		counter++;
		pointer++;

		for(i=0; i<64; i++)
		{
			counter++;
			qtable[jpeg_natural_order[i]] = *pointer++;
		}
		for(i=0;i<64;i++)								// Fill Q_Table_SRAM
		{
			*ptr++ = (unsigned int)qtable[i];
		}
	}	// while(counter < length)

	*P_MPEG4_QTABLE_SRAM = C_MPEG4_QTABLESRAM_DIS;		// disable CPU access Q Sram
}


//=============================================================
// 语法格式：	int set_jpg_mode(unsigned char *jpg_ptr);
// 实现功能：	向SPCE3200填充高度、宽度、FRAME_Buffer 宽度等信息
//				根据jpeg图片数据，选择YUV格式
// 参数：		jpg_ptr，指向jpeg数据的指针
// 返回值：		1: 成功;  0: 失败
//=============================================================

static int set_jpg_mode(unsigned char *jpg_ptr)
{
	unsigned char *pointer;
	unsigned char word;
	unsigned int width;

	pointer = jpg_ptr + 3;

	word = *pointer++;
	*P_MPEG4_DECHEIGHT_HIGH = (unsigned int)word;		// 高度
	word = *pointer++;
	*P_MPEG4_DECHEIGHT_LOW = (unsigned int)word;

	word = *pointer++;
	*P_MPEG4_DECWIDTH_HIGH = (unsigned int)word;		// 宽度
	width = (unsigned int)word;
	width = width << 8;
	
	word = *pointer++;
	*P_MPEG4_DECWIDTH_LOW = (unsigned int)word;
	width = width + (unsigned int)word;

	*P_MPEG4_FRAMEBUFFER_HSIZE = width;					// FRAMEBUFFER_HSIZE

	word = *pointer++;
	pointer++;											// skip 1 byte
	
	
    if(word==0x01)										// 单色  01
	{
		*P_MPEG4_YUV_SEL = 0x00000000;					// 0 : {yuv420, yuv422}
														// 1 : {yuv411, yuv444}
		*P_MPEG4_MODE_CTRL1 = C_MPEG4_JPEG_DEC
								| C_MPEG4_YUV422_MODE
								| C_MPEG4_COLOR_MODE;

	}
	else												// 彩色  03
	{
		word = *pointer;
		
		switch(word)									// 分量水平sampling比例
		{
			case 0x11:									// yuv444
				*P_MPEG4_YUV_SEL = 0x00000001;
				*P_MPEG4_MODE_CTRL1 = C_MPEG4_JPEG_DEC
										| C_MPEG4_YUV444_MODE;
				break;
			case 0x21:									// yuv422
				*P_MPEG4_YUV_SEL = 0x00000000;
				*P_MPEG4_MODE_CTRL1 = C_MPEG4_JPEG_DEC
										| C_MPEG4_YUV422_MODE;
				break;
			case 0x41:									// yuv411
				*P_MPEG4_YUV_SEL = 0x00000001;
				*P_MPEG4_MODE_CTRL1 = C_MPEG4_JPEG_DEC
										| C_MPEG4_YUV411_MODE;
				break;
			case 0x22:									// yuv420
				*P_MPEG4_YUV_SEL = 0x00000000;
				*P_MPEG4_MODE_CTRL1 = C_MPEG4_JPEG_DEC
										| C_MPEG4_YUV420_MODE;
				*P_MPEG4_YUV_MODE = 0x30;
				break;
			case 0x12:									// 不支持 单 垂直采样2:1模式
				return 0;								// i can't decode this JPG file
		}	// end switch
	}	// end if
	return 1;
}	// end function

//=============================================================
// 语法格式：	Get_Huffman_cs_cw(unsigned char *cs, unsigned int *cw, unsigned char *pointer);
// 实现功能：	获得Huffman表
// 参数：		*cs，huffman的VLC的相对开始；*cw，存储huffman表；*pointer，指向jpeg数据
// 返回值：		无
//=============================================================
static void Get_Huffman_cs_cw(unsigned char *cs, unsigned int *cw, unsigned char *pointer)
{
	unsigned char pcount[16];
	unsigned int index;
	unsigned int l_codeword = 0;						// local_codeword
	unsigned int last_valid;
	unsigned int j;
	
	for(j=0; j<16; j++)
	{
		pcount[j] = *pointer++;
	}
	for(j=15; j>=0; j--)
	{
		if(pcount[j])
			break;
	}

	last_valid = j;

	for(index=0; index<16; index++)
	{
		if(0 == index)
		{
			cs[0] = 0;
		}
		else if(1 == index)
		{
			cs[1] = pcount[0];
		}
		else
		{
			cs[index] = cs[index - 1] + pcount[index - 1];
		}	// end if(0 == index)

		if(index == 0)
		{
			cw[index] = 0;
			if(pcount[0] == 1)
				l_codeword = 1;
			else
				l_codeword = 0;
		}
		else if(index <= last_valid)
		{
			if(0 == cs[index])
			{
				l_codeword = 0;
			}
			l_codeword = l_codeword << 1;
			cw[index] = l_codeword;
			l_codeword = l_codeword + pcount[index];
		}
		else
		{
			cw[index] = 0xffff;
		}	// end if(index == 0)
	} // end for(index=0; index<16; index++)
}

//=============================================================
// 语法格式：	void set_Huff_sram_mode(int Page);
// 实现功能：	向SPCE3200填充TSRAM，前4页存储亮度信息，后4页存储色度信息
// 参数：		Page，选择TSRAM的页数
// 返回值：		无
//=============================================================
static void set_Huff_sram_mode(int Page)
{
	if(Page == 0)
		*P_MPEG4_TSRAM_CTRL = C_MPEG4_CPU_TSRAM
								| C_MPEG4_TSRAM_PAGE0;
	else if(Page == 1)
		*P_MPEG4_TSRAM_CTRL = C_MPEG4_CPU_TSRAM
								| C_MPEG4_TSRAM_PAGE1;
	else if(Page == 2)
		*P_MPEG4_TSRAM_CTRL = C_MPEG4_CPU_TSRAM
								| C_MPEG4_TSRAM_PAGE2;
	else if(Page == 3)
		*P_MPEG4_TSRAM_CTRL = C_MPEG4_CPU_TSRAM
								| C_MPEG4_TSRAM_PAGE3;
	else if(Page == 4)
		*P_MPEG4_TSRAM_CTRL = C_MPEG4_CPU_TSRAM
								| C_MPEG4_TSRAM_PAGE4;
	else if(Page == 5)
		*P_MPEG4_TSRAM_CTRL = C_MPEG4_CPU_TSRAM
								| C_MPEG4_TSRAM_PAGE5;
	else if(Page == 6)
		*P_MPEG4_TSRAM_CTRL = C_MPEG4_CPU_TSRAM
								| C_MPEG4_TSRAM_PAGE6;
	else if(Page == 7)
		*P_MPEG4_TSRAM_CTRL = C_MPEG4_CPU_TSRAM
								| C_MPEG4_TSRAM_PAGE7;
	else
		*P_MPEG4_TSRAM_CTRL = C_MPEG4_CPU_REG;
}

//=============================================================
// 语法格式：	set_jpg_huffman_cw_reg(unsigned char htype, unsigned int *cw);
// 实现功能：	填充Huffman表
// 参数：		htype，huffman表的类型；*cw，存储的huffman表
// 返回值：		无
//=============================================================
static void set_jpg_huffman_cw_reg(unsigned char htype, unsigned int *cw)
{
	unsigned int i;
	unsigned int *pointer;

	if(htype == 0x00)
		pointer = (unsigned int *)P_MPEG4_HUFFMAN_START;				// YDC huffman
	else if(htype == 0x01)
		pointer = (unsigned int *)P_MPEG4_CHROMDCCODE_START;			// CDC huffman
	else if(htype == 0x10)
		pointer = (unsigned int *)P_MPEG4_LUMACHUFFMANTABLE_START;		// YAC huffman
	else if(htype == 0x11)
		pointer = (unsigned int *)P_MPEG4_CHROMACHUFFMANTABLE_START;	// CAC huffman

	for(i=0; i<8; i++)
	{
		*pointer++ = cw[i];
	}
	for(i=8; i<16; i++)
	{
		*pointer++ = cw[i];
		*pointer++ = cw[i] >> 8;
	}
}

//=============================================================
// 语法格式：	set_jpg_huffman_acs_reg(int chrominance, unsigned char *cs);
// 实现功能：	填充 AC Huffman VLC偏移
// 参数：		chrominance，选择亮度还是色度；*cs，VLC偏移
// 返回值：		无
//=============================================================
static void set_jpg_huffman_acs_reg(int chrominance, unsigned char *cs)
{
	unsigned int i;
	unsigned int *pointer;
	
	if(chrominance == 0)
	{
		pointer = (unsigned int *)P_MPEG4_LUMACHUFFMANOFFSET_SA;
	}
	else
	{
		pointer = (unsigned int *)P_MPEG4_CHROMACHUFFMANOFFSET_SA;
	}
	
	for(i=0; i<16; i++)
	{
		*pointer++ = (unsigned int)cs[i];
	}
}

//=============================================================
// 语法格式：	set_jpg_huffman_acs_reg(int chrominance, unsigned char *cs);
// 实现功能：	填充 AC Huffman值
// 参数：		chrominance，选择亮度还是色度；*cv，AC huffman值
// 返回值：		无
//=============================================================
static void set_jpg_huffman_acv_sram(int chrominance, unsigned char *cv)
{
	unsigned int Huffman_SRAM_Page;
	unsigned int *pointer;
	unsigned int j, i, k;
	
	if(chrominance == 0)
		Huffman_SRAM_Page = 0;
	else
		Huffman_SRAM_Page = 4;
	
	for(j=0; j<4; j++)
	{
		set_Huff_sram_mode(Huffman_SRAM_Page);
		pointer = (unsigned int *)P_MPEG4_LUMDCCODE_START;
		k= j * 64;
		
		for(i=0; i<64; i++)
		{
			*pointer++ = (unsigned int)cv[k++];
		}
		Huffman_SRAM_Page++;
	}
	set_Huff_sram_mode(8);
}

//=============================================================
// 语法格式：	void set_jpg_huffman_dcs_reg(int chrominance, unsigned char *cs);
// 实现功能：	填充 DC Huffman VLC偏移
// 参数：		chrominance，选择亮度还是色度；*cs，VLC偏移
// 返回值：		无
//=============================================================
static void set_jpg_huffman_dcs_reg(int chrominance, unsigned char *cs)
{