【求助】用VedioWriter输出avi视频文件，视频却无法打开是为什么？

qq_41571940 2020-03-01 10:07:06

这个设计的思路是将一副图片嵌入视频中，先逐帧读取视频，对每一帧视频进行8X8dct变换，然后将要嵌入的像素X分为八位比特位，选四个中频系数嵌入,每次嵌入两个x1,x2。嵌入方法是将中频系数的载体像素Y提取后三位y1,y2,y3,分别异或y1^y2,y1^y3生成校验位c1,c1再与x1,x2异或会有四种结果，根据结果分别修改y1,y2,y3或者不改就是了。
当然这个不是重点.....重点是现在用opencv读取视频进行以上操作后输出avi文件，现在文件是输出了但是无法打开，是不是我哪里写错了？另外这个代码效率有点低，也请大神帮忙指点一下怎么改进效率谢谢。
代码如下：



#include "pch.h"

#include<string>

#include<cstdio>

#include <fstream>  

#include <iostream> 

#define ERROR_STR_SIZE 1024

using namespace std;

using namespace cv;

String todString(String en)

{

	if (en.length() == 8)

	{

		return en;

	}

	else

	{

		for (int i = en.length(); i < 8; i++) {

			en = "0" + en;

		}

		return en;

	}

}

int PixelTransformation(int em, string im)

{

	//cout << "em:" << em << endl;

	//cout << "im.substuct:" << im << endl;

	int inter = abs(em),y3=inter%2,y2=(inter/2)%2,y1=(inter/4)%2;

	//cout << "y1:" << y1 << " y2:" << y2 << " y3:" <<y3<< endl;

	int check1 = y1 ^ y2, check2 = y1 ^ y3,check=check1*2+check2,emb=stoi(im,nullptr,2),Result= check ^ emb;

	//cout << "check1:" << check1 << " check2:" << check2 << " check:" << check<<" emb:"<<emb<<" Result:"<< Result <<endl;

	switch (Result)

	{

	case 0:

		return inter;

	case 1:

		return inter ^ 1;

	case 2:

		return inter ^ 2;

	case 3:

		return inter ^ 4;

	default:

		break;

	}

}

void MyFFmpeg::ffmpegVideoDecodecWithFilePath(const char* filepath,Mat en)

{

	Mat src,srcYuv, srcY,srcU,srcV,Y;

	Mat imgdst, imgdst2;

	int Embedded, enindexX = 0,enindexY=0,imindex=0;

	int ca, emb1,emb2,emb3,emb4;

	int enrows = en.rows, encols = en.cols;

	int embits1, embits2, embits3, embits4;



	vector<Mat> channels;

	

	char embeddedbyte[9];

	

	Rect window;

	window.height = 8;

	window.width = 8;



	//imshow("en", en);

	//en.convertTo(src, CV_32FC1);

	Embedded = (int)en.at<uchar>(enindexX, enindexY);

	_itoa_s(Embedded, embeddedbyte,9,2);

	string im=embeddedbyte;

	im = todString(im);

	size_t index = 0;

	VideoCapture capture(filepath);

	int frame_width = static_cast<int>(capture.get(CAP_PROP_FRAME_WIDTH));

	int frame_height = static_cast<int>(capture.get(CAP_PROP_FRAME_HEIGHT));

	float frame_fps = capture.get(CAP_PROP_FPS);

	int frame_number = static_cast<int>(capture.get(CAP_PROP_FRAME_COUNT));//总帧数

	cout << "frame_width is " << frame_width << endl;

	cout << "frame_height is " << frame_height << endl;

	cout << "frame_fps is " << frame_fps << endl;

	cout << "frame_frame_number" << frame_number << endl;

	//src = capture.open(filepath);

	int type = static_cast<int>(capture.get(CAP_PROP_FOURCC));

	VideoWriter writer("VideoTest.flv", type, frame_fps, Size(frame_width, frame_height),true);

	//float* pixelPtr = NULL;

	if (capture.isOpened())

	{

		cout << "Open Success!";

	}



	while (capture.read(src))

	{



		cvtColor(src, srcYuv, cv::COLOR_BGR2YUV);

		//imshow("src", src);

		//waitKey(0);

		//分割通道

		

		split(srcYuv, channels);

		srcY = channels.at(0);

		srcU = channels.at(1);

		srcV = channels.at(2);

		//imshow("Ychannels",srcY);

		//imshow("Uchannels", srcU);

		//imshow("Vchannels", srcV);

		//waitKey(0);

		//深度转换

		Mat DCTY(src.size(), CV_32FC1);

		Mat iDCTY(src.size(), CV_32FC1);

		srcY.convertTo(Y, CV_32FC1);

		int ycols = Y.cols / 8, yrows = Y.rows / 8;

		for (int n = 0; n < ycols; n++)

		{

			for (int m = 0; m < yrows; m++)

			{

				window.x = 8 * n;

				window.y = 8 * m;

				dct(Y(window), DCTY(window));

				//cout << DCTY(window) << endl;

				//cout << DCTY(window) << endl;

				//DCTY(window) -= 127;

				//cout << DCTY(window) << endl;

				//DCTY(window) /= mask;

				//cout << DCTY(window) << endl; 

				/*for (int j = 0; j < 4; j++)

				{

					ca = llroundf(DCTY.at<float>(j, 4 - j));

					//cout << "ca:" << ca<<endl;

					emb = PixelTransformation(ca, im.substr(imindex, 2));

					//cout << "DCTYemb:" << emb << endl;

					DCTY(window).at<float>(j, 4 - j) = (ca >= 0) ? emb : -emb;

					//cout << "DCT.at:" << DCTY.at<float>(j, 3 - j + num) << " ";

					imindex += 2;

				}*/

				//pixelPtr = DCTY.ptr<float>(0);

				embits1=llroundf(DCTY(window).ptr<float>(0)[4]);

				embits2=llroundf(DCTY(window).ptr<float>(1)[3]);

				embits3=llroundf(DCTY(window).ptr<float>(2)[2]);

				embits4=llroundf(DCTY(window).ptr<float>(3)[1]);

				//cout << embits1 << " " << embits2 << " " << embits3 << " " << embits4<<endl;

				emb1 = PixelTransformation(embits1, im.substr(0, 2));

				emb2 = PixelTransformation(embits2, im.substr(2, 2));

				emb3 = PixelTransformation(embits3, im.substr(4, 2));

				emb4 = PixelTransformation(embits4, im.substr(6, 2));

				//cout << emb1 << " " << emb2 << " " << emb3 << " " << emb4 << endl;

				DCTY(window).ptr<float>(0)[4] = (embits1 >= 0) ? emb1 : -emb1;

				DCTY(window).ptr<float>(1)[3] = (embits2 >= 0) ? emb2 : -emb2;

				DCTY(window).ptr<float>(2)[2] = (embits3 >= 0) ? emb3 : -emb3;

				DCTY(window).ptr<float>(3)[1] = (embits4 >= 0) ? emb4 : -emb4;

				

				//cout << DCTY(window)<< endl;

				//imindex = 0;

				enindexY = (enindexX + 1 <= encols - 1) ? enindexY : enindexY + 1;

				//cout << enindexY;

				enindexX = (enindexX + 1 <= encols - 1) ? enindexX + 1 : 0;

				enindexY = (enindexY + 1 <= enrows - 1) ? enindexY : 0;



				Embedded = (int)en.at<uchar>(enindexY, enindexX);

				_itoa_s(Embedded, embeddedbyte, 9, 2);

				

				im = embeddedbyte;



				im = todString(im);

				idct(DCTY(window), DCTY(window));

			}

		}

		DCTY.convertTo(iDCTY, CV_8UC1);

		//imshow("iDCTY", iDCTY);

		//waitKey(0);

		Mat img[] = { iDCTY,srcU,srcV };

		

		merge(img, 3, imgdst);

		cvtColor(imgdst, imgdst2, COLOR_YUV2BGR);

		//cvtColor(src, imgdst, COLOR_YUV2BGR);

		//imshow("imgdst", imgdst2);

		//imshow("src", src);

		//waitKey(1);

		writer.write(imgdst2);

		

	}

	/*

	 * 关闭解码器

	 *

	*/

	writer.release();

	capture.release();



	cout << "end" << endl;

}