信号系统综合实践报告.docx

大连理工大学

本科实验报告

课程名称： 信号综合处理实践
学院（系）： 信息与通信工程学院
专 业： 电子信息工程（英强）
班 级： 电英1401班
学 生 1 ： 李帆 201483089
学 生 2 ： 马壮 201483082
学 生 3 ： 王瑞明 201483133

2017 年 10 月 12 日
题目：实验39 字幕式文字显示
一、 方法的原理
本课题为字幕式文字显示，将提前设定的文字在显示器上动态显示，随着时间逐渐移动，实现弹幕的滚动效果。主要的方法原理是，对指定文字进行字符化处理，形成32px*32px的汉字阵列，在显示器上对平面坐标进行设定，确定字符的初始位置，并确定字符间的相对位置，设定二维平面内字幕的移动方向和速度，从而实现字幕的动态效果。同时，对显示器背景和字符的灰度进行调整，实现较好的演示效果。
1、汉语文字的字符点阵处理：
在灰度图像中，文字可以用像素点的形式显示，改变不同像素点位置的灰度值，可以实现文字的正确显示。我们对汉字进行像素点阵处理，将单个汉字表示成自由设定的大小，计算出汉字占据的像素点，从而显示出汉字的图形。
利用汉字字模软件PCtoLCD2002，可以很简便地得到一般汉字的点阵表示。在软件中输入汉字内容，调整点阵背景大小和汉字的字体及大小，自动生成像素坐标形式，确定坐标可以进一步实现汉字的正确显示。我们对示例文字采用宋体，背景和汉字大小均为32px*32px，这样在屏幕上显示效果较好。在程序中，我们将三名组员的姓名的每个字分别用像素点表示，作为查询表进行显示。

图1 生成汉字“李帆”像素点表示示例

2、对显示器进行初始化设定
对显示器参数进行设定，屏幕宽度设为720，高度设为576，帧间隔设为25，最大帧率为25000。由于是灰度图像显示，所以对显示器背景色和汉字颜色采用灰度级表示，我们设定背景色为纯黑0x00，将汉字设为纯白0xff，便于清楚地显示。
3、 字幕文字位置及移动方式设定
对显示器进行二位平面坐标处理后，文字的位置以坐标的形式在显示器显示。将文字作为整体，实现移动效果。我们将中心字设为“马”，规定汉字第一个像素点的坐标为place_x和place_y，在(x,y)至(x+32,y+32)内的矩阵将显示汉字“马”。我们在每一行显示一个成员名字，这样之后每个的汉字只需对x累加32即可实现。确定行间距也为32px，这样在每一列上只需对中心字分别做处理(y+64)和(y-64)。由此实现了一个整体操作，改变place_x和place_y的数值，可以实现字幕的滚动。滚动方式设定为以对角线形式下降，所以在每帧上使横纵坐标均累加，实现语句为 place_x+=5; place_y+=5; 改变符号和大小，可以引起字幕文字移动的方向和快慢。显而易见，place_x累加则向右移动，place_x累减则向左移动，place_y累加则向下移动，place_y累减则向上。如果字幕文字接近边界，我们设定字幕坐标回到初始0点，实现语句为 if(place_x>600) place_x=0; 这样可以实现往复滚动，这样更符合网站弹幕的设定。初始位置横纵坐标均设为100，实现语句为提前定义 int place_x=100; int place_y=100;
经过以上方法的讨论，可以将字幕正确转化为图像像素点，并在显示器上以平面坐标的形式显示，在显示后可以实现字幕的自由移动。

二、 代码和效果图
核心代码实现如下：
/*
* ======== video_encdec.c ========
*
*/

/* Codec Engine include files: */
#include <xdc/std.h>
#include <ti/sdo/ce/Engine.h>
#include <ti/sdo/ce/osal/Memory.h>
#include <ti/sdo/ce/video/videnc.h>
#include <ti/sdo/ce/video/viddec.h>

/* BIOS include files: */
#include <ti/bios/include/std.h>
#include <tsk.h>

/* Run Time lib include files: */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>

/* PSP include files: */
#include <psp_vpfe.h>
#include <psp_vpbe.h>
#include <fvid.h>
#include <psp_tvp5146_extVidDecoder.h>

/* BSL include files */
#include <evmdm6437.h>
//#include <evmdm6437_dip.h>

/* Video Params Defaults */
#include <vid_params_default.h>

/* Video Encoder initialization param: */
#define VE_MAX_BR (4000000)

/* Align on cache-line boundary since encoder uses DMA */
#define BUFALIGN 128

/* Number of buffers to allocate for video capture + display: */
#define FRAME_BUFF_CNT 6

/* This example supports either PAL or NTSC depending on position of JP1 */
#define STANDARD_PAL 0
#define STANDARD_NTSC 1

/* Video Encoder parameters for D1, set depending on PAL vs NTSC: */
static int intraFrameInterval;
static int inputWidth;
static int inputHeight;
static int maxFrameRate;
/* Encoder Input, Encoder output, and Decoder Output Frame sizes */
static int framesize;

/* Video Frame buffers: */
static FVID_Frame *frameBuffTable[FRAME_BUFF_CNT];
static FVID_Frame *frameBuffPtr = NULL;

/* Video Driver Handles: */
static FVID_Handle hGioVpfeCcdc = NULL;
static FVID_Handle hGioVpbeVid0 = NULL;
static FVID_Handle hGioVpbeVenc = NULL;

/* Intermediate buffer for the encoded video stream: */
static XDAS_Int8 *encodedBuf;

/* Codec Engine engine and codec labels, defined in cfg file: */
static String decoderName = "h264dec";
static String encoderName = "h264enc";
static String engineName = "encdec";

static String progName = "app";

/* Function prototypes */
static Void initVE_StaticParams(VIDENC_Params *vencParams);
static Void initVE_DynamicParams(VIDENC_DynamicParams *encDynParams);
static Void initVD_StaticParams(VIDDEC_Params *vdecParams);
static Void initVD_DynamicParams(VIDDEC_DynamicParams *decDynParams);
static Void encode_decode(VIDENC_Handle enc, VIDDEC_Handle dec);
//static int read_JP1(void);

/*
* ======== video_encdec ========
*/
/* ARGSUSED */
Int video_encdec(Int argc, String argv[])
{

int status = 0;
int result;
int i;

Engine_Handle ce = NULL;
VIDDEC_Handle dec = NULL;
VIDENC_Handle enc = NULL;

VIDENC_Status encStatus;
VIDENC_Params vencParams;
VIDENC_DynamicParams encDynParams;

VIDDEC_Status decStatus;
VIDDEC_Params vdecParams;
VIDDEC_DynamicParams decDynParams;

int standard;

/* Set video display/capture driver params to defaults */
PSP_VPFE_TVP5146_ConfigParams tvp5146Params =
VID_PARAMS_TVP5146_DEFAULT;
PSP_VPFECcdcConfigParams vpfeCcdcConfigParams =
VID_PARAMS_CCDC_DEFAULT_D1;
PSP_VPBEOsdConfigParams vpbeOsdConfigParams =
VID_PARAMS_OSD_DEFAULT_D1;
PSP_VPBEVencConfigParams vpbeVencConfigParams;

printf("video_encdec started.\n");

// standard = read_JP1();
standard =STANDARD_PAL;

/* Update display/capture params based on video standard (PAL/NTSC) */
if (standard == STANDARD_PAL) {
inputWidth = 720;
inputHeight = 576;
intraFrameInterval = 25;
maxFrameRate = 25000;
vpbeVencConfigParams.displayStandard = PSP_VPBE_DISPLAY_PAL_INTERLACED_COMPOSITE;
}
else {
inputWidth = 720;
inputHeight = 480;
intraFrameInterval = 30;
maxFrameRate = 30000;
vpbeVencConfigParams.displayStandard = PSP_VPBE_DISPLAY_NTSC_INTERLACED_COMPOSITE;
}
framesize = (inputWidth * inputHeight * 2 * sizeof(Int8));
vpfeCcdcConfigParams.height = vpbeOsdConfigParams.height = inputHeight;
vpfeCcdcConfigParams.width = vpbeOsdConfigParams.width = inputWidth;
vpfeCcdcConfigParams.pitch = vpbeOsdConfigParams.pitch = inputWidth * 2;

/* Initialize Video Display Driver: */
/* create video input channel */
if (status == 0) {
PSP_VPFEChannelParams vpfeChannelParams;
vpfeChannelParams.id = PSP_VPFE_CCDC;
vpfeChannelParams.params = (PSP_VPFECcdcConfigParams*)&vpfeCcdcConfigParams;
hGioVpfeCcdc = FVID_create("/VPFE0",IOM_INOUT,NULL,&vpfeChannelParams,NULL);
status = (hGioVpfeCcdc == NULL ? -1 : 0);
}

/* create video output channel, plane 0 */
if (status == 0) {
PSP_VPBEChannelParams vpbeChannelParams;
vpbeChannelParams.id = PSP_VPBE_VIDEO_0;
vpbeChannelParams.params = (PSP_VPBEOsdConfigParams*)&vpbeOsdConfigParams;
hGioVpbeVid0 = FVID_create("/VPBE0",IOM_INOUT,NULL,&vpbeChannelParams,NULL);
status = (hGioVpbeVid0 == NULL ? -1 : 0);
}

/* create video output channel, venc */
if (status == 0) {
PSP_VPBEChannelParams vpbeChannelParams;
vpbeChannelParams.id = PSP_VPBE_VENC;
vpbeChannelParams.params = (PSP_VPBEVencConfigParams *)&vpbeVencConfigParams;
hGioVpbeVenc = FVID_create("/VPBE0",IOM_INOUT,NULL,&vpbeChannelParams,NULL);
status = (hGioVpbeVenc == NULL ? -1 : 0);
}

/* configure the TVP5146 video decoder */
if (status == 0) {
result = FVID_control(hGioVpfeCcdc,
VPFE_ExtVD_BASE+PSP_VPSS_EXT_VIDEO_DECODER_CONFIG, &tvp5146Params);
status = (result == IOM_COMPLETED ? 0 : -1);
}

/* allocate display/capture frame buffers */
for (i=0; i<FRAME_BUFF_CNT; i++) {
frameBuffTable[i] = NULL;
}
if (status == 0) {
for (i=0; i<FRAME_BUFF_CNT && status == 0; i++) {
result = FVID_allocBuffer(hGioVpfeCcdc, &frameBuffTable[i]);
status = (result == IOM_COMPLETED && frameBuffTable[i] != NULL ? 0 : -1);
}
}

/* prime up the video capture channel */
if (status == 0) {
FVID_queue(hGioVpfeCcdc, frameBuffTable[0]);
FVID_queue(hGioVpfeCcdc, frameBuffTable[1]);
FVID_queue(hGioVpfeCcdc, frameBuffTable[2]);
}

/* prime up the video display channel */
if (status == 0) {
FVID_queue(hGioVpbeVid0, frameBuffTable[3]);
FVID_queue(hGioVpbeVid0, frameBuffTable[4]);
FVID_queue(hGioVpbeVid0, frameBuffTable[5]);
}

/* grab first buffer from input queue */
if (status == 0) {
FVID_dequeue(hGioVpfeCcdc, &frameBuffPtr);
}

if (status != 0) {
goto end;
}

/* Allocate Encoder output buffer: */
/* encodedBuf = (XDAS_Int8 *)Memory_contigAlloc(framesize, BUFALIGN);
if (encodedBuf == NULL) {
goto end;
}
else {
Memory_cacheWbInv(encodedBuf, framesize);
}
*/

/* use engine to encode, then decode the data */
encode_decode(enc, dec);

end:

/* Free Video Driver resources: */
if (hGioVpfeCcdc) {
for (i=0; i<FRAME_BUFF_CNT && status == 0; i++) {
FVID_freeBuffer(hGioVpfeCcdc, frameBuffTable[i]);
}
}

/* Delete Channels */
if (hGioVpfeCcdc) {
FVID_delete(hGioVpfeCcdc);
}
if (hGioVpbeVid0) {
FVID_delete(hGioVpbeVid0);
}
if (hGioVpbeVenc) {
FVID_delete(hGioVpbeVenc);
}

printf("video_encdec done.\n");
return (0);
}

/*
* ======== initVE_StaticParams ========
*/
static Void initVE_StaticParams(VIDENC_Params * vencParams)
{
/* Set Constant Bit Rate, YUV422 Interlaced, little endian: */
vencParams->size = sizeof(VIDENC_Params);
vencParams->encodingPreset = XDM_DEFAULT;
vencParams->rateControlPreset = IVIDEO_LOW_DELAY;
vencParams->maxHeight = inputHeight;
vencParams->maxWidth = inputWidth;
vencParams->maxFrameRate = maxFrameRate;
vencParams->maxBitRate = VE_MAX_BR;
vencParams->dataEndianness = XDM_BYTE;
vencParams->maxInterFrameInterval = 0;
vencParams->inputChromaFormat = XDM_YUV_422ILE;
vencParams->inputContentType = IVIDEO_PROGRESSIVE;

return;
}

/*
* ======== initVE_DynamicParams ========
*/
static Void initVE_DynamicParams(VIDENC_DynamicParams *encDynParams)
{
encDynParams->inputHeight = inputHeight;
encDynParams->inputWidth = inputWidth;
encDynParams->refFrameRate = maxFrameRate;
encDynParams->targetFrameRate = maxFrameRate;
encDynParams->targetBitRate = VE_MAX_BR;
encDynParams->intraFrameInterval = intraFrameInterval;
encDynParams->generateHeader = XDM_ENCODE_AU;
encDynParams->captureWidth = 0;
encDynParams->forceIFrame = 0;

return;
}

/*
* ======== initVD_StaticParams ========
*/
static Void initVD_StaticParams(VIDDEC_Params * vdecParams)
{
/* Set Constant Bit Rate, YUV422 Interlaced, little endian: */
vdecParams->size = sizeof(VIDDEC_Params);

vdecParams->maxHeight = inputHeight;
vdecParams->maxWidth = inputWidth;
vdecParams->maxFrameRate = 0;
vdecParams->maxBitRate = 0;
vdecParams->dataEndianness = XDM_BYTE;
vdecParams->forceChromaFormat = XDM_YUV_422ILE;

return ;
}

/*
* ======== initVD_DynamicParams ========
*/
static Void initVD_DynamicParams(VIDDEC_DynamicParams *decDynParams)
{
decDynParams->decodeHeader = XDM_DECODE_AU;
decDynParams->displayWidth = 0;
decDynParams->frameSkipMode = IVIDEO_NO_SKIP;

return;
}

void GrayImage(Uint8 *in_data)
{
Uint32 i,j;
for(i = 0; i < 576; i++)
for(j=0; j <720; j++)
{
*(Uint8 *)(in_data + (i*720 + j) * 2) = 0x80;
}
}

void GrayImage_y(Uint8 *in_data)
{
Uint32 i,j;
for(i = 0; i < 576; i++)
for(j=0; j <720; j++)
{
*(Uint8 *)(in_data +1+ (i*720 + j) * 2) = 0x0;
}
}

Uint8 li[1024/8]={
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x40,0x00,0x01,0x00,0x42,0x00,
0x01,0x00,0x82,0x00,0x01,0x01,0x02,0x00,0x01,0x01,0x02,0x00,0x01,0x02,0x02,0x00,
0x01,0x06,0x02,0x00,0x01,0x0C,0x82,0x00,0x01,0x18,0x82,0x00,0x01,0x30,0x82,0x08,
0x01,0xE0,0x82,0x08,0x01,0xC0,0x82,0x0C,0x01,0x80,0x82,0x0C,0x3F,0xFE,0x82,0x0E,
0x1F,0xFC,0x9F,0xFC,0x11,0x00,0x9F,0xF8,0x01,0x80,0xA2,0x00,0x01,0x60,0xE2,0x00,
0x01,0x30,0xC2,0x00,0x01,0x1B,0xC2,0x00,0x01,0x0D,0x82,0x00,0x01,0x06,0x82,0x00,
0x01,0x06,0x02,0x00,0x01,0x07,0x02,0x00,0x02,0x03,0x02,0x00,0x06,0x03,0x86,0x00,
0x02,0x03,0x06,0x00,0x00,0x00,0x02,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
,/*"李",0*/

};

Uint8 fan[1024/8]={
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0xFF,0xFF,0x00,0x00,0xFF,0xFE,0x00,
0x00,0x80,0x00,0x00,0x00,0x80,0x00,0x00,0x00,0x80,0x00,0x00,0x3F,0xFF,0xFF,0xFE,
0x10,0x80,0x00,0x02,0x00,0x80,0x04,0x02,0x00,0x80,0x06,0x02,0x00,0xFF,0xFF,0x04,
0x00,0xFF,0xFC,0x08,0x00,0x00,0x00,0x30,0x00,0x00,0x00,0x60,0x00,0x00,0x07,0xC0,
0x0F,0xFF,0xFE,0x00,0x07,0xFE,0x00,0x00,0x04,0x08,0x00,0x00,0x04,0x06,0x00,0x00,
0x04,0x03,0xC0,0x00,0x04,0x01,0xC0,0x00,0x04,0x00,0x00,0x00,0x0F,0xFF,0xFF,0xF8,
0x0F,0xFF,0xFF,0xF8,0x00,0x00,0x00,0x0C,0x00,0x00,0x00,0x08,0x00,0x00,0x00,0x08,
0x00,0x00,0x03,0xF8,0x00,0x00,0x00,0x38,0x00,0x00,0x00,0x10,0x00,0x00,0x00,0x00
,/*"帆",0*/

};

Uint8 wang[1024/8]={
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x08,0x00,0x00,0x00,0x08,
0x02,0x00,0x00,0x08,0x02,0x00,0x00,0x08,0x02,0x00,0x40,0x08,0x02,0x00,0x40,0x08,
0x02,0x00,0x40,0x08,0x02,0x00,0x40,0x08,0x02,0x00,0x40,0x08,0x02,0x00,0x40,0x08,
0x02,0x00,0x40,0x08,0x02,0x00,0x40,0x08,0x02,0x00,0x40,0x08,0x03,0xFF,0xFF,0xF8,
0x03,0xFF,0xFF,0xF8,0x02,0x00,0x40,0x08,0x02,0x00,0x40,0x08,0x02,0x00,0x40,0x08,
0x02,0x00,0x40,0x08,0x02,0x00,0x40,0x08,0x02,0x00,0x40,0x08,0x02,0x00,0x40,0x08,
0x02,0x00,0x80,0x08,0x02,0x00,0x80,0x08,0x06,0x00,0x00,0x08,0x06,0x00,0x00,0x18,
0x02,0x00,0x00,0x18,0x00,0x00,0x00,0x08,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
,/*"王",0*/

};

Uint8 rui[1024/8]={
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x02,0x00,0xE0,0x02,0x02,0x00,0xC0,
0x02,0x02,0x00,0xC0,0x02,0x02,0x00,0x80,0x03,0xFF,0xFF,0x80,0x03,0xFF,0xFF,0x00,
0x02,0x02,0x01,0x00,0x02,0x06,0x02,0x00,0x06,0x02,0x02,0x00,0x02,0x02,0x02,0x00,
0x00,0x02,0x00,0x00,0x00,0x42,0x7F,0xFE,0x0F,0xE2,0x20,0x00,0x04,0x42,0x20,0x00,
0x00,0x42,0x20,0x00,0x00,0x42,0x3F,0xF8,0x00,0x43,0xFF,0xF0,0x00,0x43,0x20,0x00,
0x3F,0xC2,0x20,0x00,0x10,0x42,0x20,0x00,0x00,0x42,0x3F,0xF8,0x00,0x42,0x20,0x04,
0x00,0x42,0x20,0x04,0x00,0x42,0x20,0x04,0x0F,0xE2,0x20,0x06,0x0F,0xE4,0xFF,0xFC,
0x00,0x0C,0x20,0x00,0x00,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00
,/*"瑞",0*/

};

Uint8 ming[1024/8]={
0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
0x07,0xFF,0xFF,0x00,0x07,0xFF,0xFE,0x00,0x02,0x04,0x08,0x00,0x02,0x04,0x08,0x00,
0x02,0x04,0x08,0x00,0x02,0x04,0x08,0x02,0x02,0x04,0x08,0x02,0x07,0xFF,0xFE,0x04,
0x07,0xFF,0xFC,0x08,0x02,0x00,0x00,0x18,0x00,0x00,0x00,0x30,0x00,0x00,0x00,0xE0,
0x00,0x00,0x0F,0x80,0x1F,0xFF,0xFE,0x00,0x0F,0xFF,0xD0,0x00,0x08,0x10,0x10,0x00,
0x08,0x10,0x10,0x00,0x08,0x10,0