C++解析AVI文件格式学习总结

一、AVI简介

AVI英文全称为Audio
Video Interleaved，即音频视频交错格式，一种多媒体容器格式。AVI文件将音频和视频

包含在一个文件容器中，允许音视频同步回放。

AVI 1.0 由于索引地址与大小用4字节表示，所以最大支持4G容量，而且与文件系统类型有关； 
AVI 2.0 AVI的扩展格式，解决AVI 1.0大小限制；
本文主要分析AVI 1.0，H264编码视频。

二、AVI格式示意图

三、各部分详细介绍

     AVI文件通常有如下几个子块组成：

1）”hdrl” list：音视频信息，描述媒体流信息；
2）”info” list：编码该AVI的程序信息；
3）”junk” chunk：无用数据，用于字节对齐；
4）”movi” list：交错排列的音视频数据；
5）”idxl” chunk：音视频排列的索引数据。

1、”hdrl” list

2、”info” list和”junk” chunk

       3、”movi” list

     4、”idxl” chunk

四、解析代码

#include <iostream>

#include <fstream>

using namespace std;

#pragma pack(1)//设定为1
20000
字节对齐

#define AVIF_HASINDEX  0x00000010       //Index at end of file?

typedef unsigned short BYTE;

typedef unsigned short WORD;

typedef unsigned long DWORD;

typedef unsigned long FOURCC;

// MainAVIHeader

typedef struct{

DWORD dwMicroSecPerFrame;//显示每桢所需的时间ns，定义avi的显示速率

DWORD dwMaxBytesPerSec;//最大的数据传输率

DWORD dwPaddingGranularity;//记录块的长度需为此值的倍数，通常是2048

DWORD dwFlages;//AVI文件的特殊属性，如是否包含索引块，音视频数据是否交叉存储

DWORD dwTotalFrame;//文件中的总桢数

DWORD dwInitialFrames;//说明在开始播放前需要多少桢

DWORD dwStreams;//文件中包含的数据流种类

DWORD dwSuggestedBufferSize;       //建议使用的缓冲区的大小，

//通常为存储一桢图像以及同步声音所需要的数据之和

DWORD dwWidth;//图像宽

DWORD dwHeight;//图像高

DWORD dwReserved[4];//保留值

}MainAVIHeader;

typedef struct{

WORD wLeft;

WORD wTop;

WORD wRight;

WORD wBottom;

}RECT;

// strh

typedef struct{

FOURCC fccType;//4字节，表示数据流的种类 vids 表示视频数据流

//auds 音频数据流

FOURCC fccHandler;//4字节 ，表示数据流解压缩的驱动程序代号

DWORD dwFlags;//数据流属性

WORD wPriority;//此数据流的播放优先级

WORD wLanguage;//音频的语言代号

DWORD dwInitalFrames;        //说明在开始播放前需要多少桢

DWORD dwScale;//数据量，视频每桢的大小或者音频的采样大小

DWORD dwRate;//dwScale /dwRate = 每秒的采样数

DWORD dwStart;//数据流开始播放的位置，以dwScale为单位

DWORD dwLength;//数据流的数据量，以dwScale为单位

DWORD dwSuggestedBufferSize;//建议缓冲区的大小

DWORD dwQuality;//解压缩质量参数，值越大，质量越好

DWORD dwSampleSize;//音频的采样大小

RECT rcFrame;//视频图像所占的矩形

}AVIStreamHeader;

// strf:strh子块是视频数据流

typedef struct{

BYTE rgbBlue;// 蓝色分量

BYTE rgbGreen;// 绿色分量

BYTE rgbRed;// 红色分量

BYTE rgbReserved;// 保留字节（用作Alpha通道或忽略）

} RGBQUAD;

typedef struct{

DWORD dwSize;

DWORD dwWidth;

DWORD dwHeight;

WORD wPlanes;

WORD wBitCount;

DWORD dwCompression;

DWORD dwSizeImage;

DWORD dwXPelsPerMeter;

DWORD dwYPelsPerMeter;

DWORD dwClrUsed;

DWORD dwClrImportant;

}BITMAPINFOHEADER;

// strf:strh子块是音频数据流

typedef struct

{

WORD wFormatTag;

WORD wChannels;//声道数

DWORD dwSamplesPerSec;//采样率

DWORD dwAvgBytesPerSec; //WAVE声音中每秒的数据量

WORD wBlockAlign;//数据块的对齐标志

WORD wBitsPerSample;    //每次采样的数据量

WORD wSize;//此结构的大小

}WAVEFORMAT;

typedef struct{

char chunk_id[4];

DWORD is_key;

DWORD pos;

DWORD size;

}AVI_IDX;

void aviListInfo(char *pInfoBuf,int *readPos)

{

char buf[5];

DWORD dwValue=0;

int flag=0;

// list

memset(buf,0,5);

memcpy(buf,pInfoBuf+*readPos,4);

*readPos+=4;

cout<<" list: "<<buf<<endl;

// list len

dwValue=0;

memcpy((char *)&dwValue,pInfoBuf+*readPos,4);

*readPos+=4; 

cout<<" list len: "<<dwValue<<endl;

// strl

memset(buf,0,5);

memcpy(buf,pInfoBuf+*readPos,4);

*readPos+=4; 

cout<<" strl: "<<buf<<endl;

// strh

memset(buf,0,5);

memcpy(buf,pInfoBuf+*readPos,4);

*readPos+=4; 

cout<<" strh: "<<buf<<endl;

// strh len

dwValue=0;

memcpy((char *)&dwValue,pInfoBuf+*readPos,4);

*readPos+=4; 

cout<<" strh len: "<<dwValue<<endl;

// strh info

AVIStreamHeader streamHeader;

memset(&streamHeader,0,sizeof(AVIStreamHeader));

memcpy((char *)&streamHeader, pInfoBuf+*readPos,sizeof(AVIStreamHeader)); 

*readPos+=sizeof(AVIStreamHeader); 

{

cout<<endl;

cout<<" AVIStreamHeader len: "<<sizeof(AVIStreamHeader)<<endl;

memset(buf,0,5);

memcpy(buf,(char *)&streamHeader.fccType,4);

cout<<" fccType: "<<buf<<endl;

string fccType(buf);

if(0 == fccType.compare(0,4,"vids")){  // 文件类型校验

flag=0;

}

else{

flag=1;

}

memset(buf,0,5);

memcpy(buf,(char *)&streamHeader.fccHandler,4);

cout<<" fccHandler: "<<buf<<endl;

cout<<" Flags: "<<streamHeader.dwFlags<<endl;

cout<<" Priority: "<<streamHeader.dwQuality<<endl;

cout<<" Language: "<<streamHeader.wLanguage<<endl;

cout<<" InitalFrames: "<<streamHeader.dwInitalFrames<<endl;

cout<<" Scale: "<<streamHeader.dwScale<<endl;

cout<<" Rate: "<<streamHeader.dwRate<<endl;

cout<<" Start: "<<streamHeader.dwStart<<endl;

cout<<" Length: "<<streamHeader.dwLength<<endl;

cout<<" SuggestedBufferSize: "<<streamHeader.dwSuggestedBufferSize<<endl;

cout<<" Quality: "<<streamHeader.dwQuality<<endl;

cout<<" SampleSize: "<<streamHeader.dwSampleSize<<endl;

cout<<" left: "<<streamHeader.rcFrame.wLeft<<endl;

cout<<" top: "<<streamHeader.rcFrame.wTop<<endl;

cout<<" right: "<<streamHeader.rcFrame.wRight<<endl;

cout<<" bottom: "<<streamHeader.rcFrame.wBottom<<endl<<endl;

}

// strf

memset(buf,0,5);

memcpy(buf,pInfoBuf+*readPos,4);

*readPos+=4;  

cout<<" strf: "<<buf<<endl;

// strf len

dwValue=0;

memcpy((char *)&dwValue,pInfoBuf+*readPos,4);

*readPos+=4; 

cout<<" strf len: "<<dwValue<<endl;

if(0==flag) // 视频信息

{

// strf info:视频流

BITMAPINFOHEADER bmiHeader;

memset(&bmiHeader,0,sizeof(BITMAPINFOHEADER));

memcpy((char *)&bmiHeader,pInfoBuf+*readPos,sizeof(BITMAPINFOHEADER));

*readPos+=sizeof(BITMAPINFOHEADER); 

{

cout<<endl;

cout<<" BITMAPINFOHEADER len: "<<sizeof(BITMAPINFOHEADER)<<endl;

cout<<" Size: "<<bmiHeader.dwSize<<endl;

cout<<" Width: "<<bmiHeader.dwWidth<<endl;

cout<<" Height: "<<bmiHeader.dwHeight<<endl;

cout<<" Planes: "<<bmiHeader.wPlanes<<endl;

cout<<" BitCount: "<<bmiHeader.wBitCount<<endl;

cout<<" Compression: "<<bmiHeader.dwCompression<<endl;

cout<<" SizeImage: "<<bmiHeader.dwSizeImage<<endl;

cout<<" XPelsPerMeter: "<<bmiHeader.dwXPelsPerMeter<<endl;

cout<<" YPelsPerMeter: "<<bmiHeader.dwYPelsPerMeter<<endl;

cout<<" ClrUsed: "<<bmiHeader.dwClrUsed<<endl;

cout<<" ClrImportant: "<<bmiHeader.dwClrImportant<<endl;

}

}

else

{

WAVEFORMAT waveFormat;

memset(&waveFormat,0,sizeof(WAVEFORMAT));

memcpy((char *)&waveFormat,pInfoBuf+*readPos,sizeof(WAVEFORMAT));

*readPos+=sizeof(WAVEFORMAT); 

{

cout<<endl;

cout<<" WAVEFORMAT len: "<<sizeof(WAVEFORMAT)<<endl;

cout<<" FormatTag: "<<waveFormat.wFormatTag<<endl; 

cout<<" Channels: "<<waveFormat.wChannels<<endl; 

cout<<" SamplesPerSec: "<<waveFormat.dwSamplesPerSec<<endl; 

cout<<" AvgBytesPerSec: "<<waveFormat.dwAvgBytesPerSec<<endl; 

cout<<" BlockAlign: "<<waveFormat.wBlockAlign<<endl; 

cout<<" BitsPerSample: "<<waveFormat.wBitsPerSample<<endl; 

cout<<" Size: "<<waveFormat.wSize<<endl; 

}

*readPos+=waveFormat.wSize; 

}

}

int main(int argc, char* argv[])

{

char fileName[32]={0};

//const char *fileName="test.avi";

char buf[5];

DWORD dwValue=0;

DWORD fileLen=0;

DWORD frameCount=0;

int hdrlListLen=0;

char *pInfo=NULL;

int readPos=0;

DWORD moviPos=0;

cout<<"Pleade input file name:";

cin>>fileName;

cout<<" File name:"<<fileName<<endl;

ifstream aviFile;

streampos   pos;

// open

aviFile.open(fileName,ios::in | ios::binary);

if(! aviFile)

{

cout<<fileName<<" open error!"<<endl;

return -1;

}

// RIFF-4字节

memset(buf,0,5); 

aviFile.read(buf, 4); 

cout<<" riffHead: "<<buf<<endl; 

// file Len-4字节：文件总长度-8 

aviFile.read((char *)&dwValue,4); 

cout<<" file len: "<<dwValue<<endl;

// file real len 

pos   =   aviFile.tellg();     // save current position   

aviFile.seekg(0,ios::end);

fileLen =  aviFile.tellg();

    aviFile.seekg(pos);   // restore saved position 

if(fileLen!=(dwValue+8))       // 文件大小校验

{

cout<<" File is damaged!"<<endl;  

return -1;

}

// file Type-4字节

memset(buf,0,5);

aviFile.read(buf, 4); 

cout<<" file type: "<<buf<<endl; 

string aviFormat(buf);

if(0 != aviFormat.compare(0,3,"AVI"))  // 文件类型校验

{

cout<<" Isn't AVI file!"<<endl; 

return -1;

}

// hdrl list-4字节

memset(buf,0,5);

aviFile.read(buf, 4); 

cout<<" list: "<<buf<<endl;

// list Len-4字节

dwValue=0;

aviFile.read((char *)&dwValue,4); 

cout<<" list len: "<<dwValue<<endl;

hdrlListLen=dwValue;

pInfo=new char[hdrlListLen+1];

memset(pInfo,0,hdrlListLen+1);

aviFile.read(pInfo, dwValue); 

{

readPos=0;

 // list Type-4字节

memset(buf,0,5);

memcpy(buf,pInfo+readPos,4);

readPos+=4;

cout<<" list type: "<<buf<<endl; 

// avih-4字节:

memset(buf,0,5);

memcpy(buf,pInfo+readPos,4);

readPos+=4; 

cout<<" avih: "<<buf<<endl;  

// avih Len-4字节

dwValue=0;

memcpy((char *)&dwValue,pInfo+readPos,4);

readPos+=4; 

cout<<" avih len: "<<dwValue<<endl;

// avi header

MainAVIHeader mainAVIHeader;

memset(&mainAVIHeader,0,sizeof(MainAVIHeader));

memcpy((char *)&mainAVIHeader,pInfo+readPos,dwValue);

readPos+=dwValue; 

{

cout<<endl;

cout<<" MainAVIHeader len: "<<sizeof(MainAVIHeader)<<endl;

cout<<" MicroSecPerFrame: "<<mainAVIHeader.dwMicroSecPerFrame<<endl;

cout<<" MaxBytesPerSec: "<<mainAVIHeader.dwMaxBytesPerSec<<endl;

cout<<" PaddingGranularity: "<<mainAVIHeader.dwPaddingGranularity<<endl;

cout<<" Flages: "<<mainAVIHeader.dwFlages<<endl;

cout<<" TotalFrame: "<<mainAVIHeader.dwTotalFrame<<endl;

frameCount=mainAVIHeader.dwTotalFrame;

cout<<" InitialFrames: "<<mainAVIHeader.dwInitialFrames<<endl;

cout<<" Streams: "<<mainAVIHeader.dwStreams<<endl;

cout<<" SuggestedBufferSize: "<<mainAVIHeader.dwSuggestedBufferSize<<endl;

cout<<" Width: "<<mainAVIHeader.dwWidth<<endl;

cout<<" Height: "<<mainAVIHeader.dwHeight<<endl;

}

if(!mainAVIHeader.dwFlages & AVIF_HASINDEX) 

{

cout<< " Hasn't find idx info!"<<endl;

return -1;

}

// list1

cout<<endl<<" ======List1======"<<endl;

aviListInfo(pInfo,&readPos);

// list 2

if(mainAVIHeader.dwStreams>1)

{

int i;

for(i=readPos;i<hdrlListLen;)

{

memset(buf,0,5);

memcpy(buf,pInfo+readPos,4);

cout<<" buf: "<<buf<<endl; 

string listFlag(buf);

if(0==listFlag.compare(0,4,"LIST")) break;

readPos+=4; 

i=readPos;

}

// list2

cout<<endl<<" ======List2======"<<endl;

aviListInfo(pInfo,&readPos);

}

cout<< " readPos="<<readPos<<endl;

}

delete []pInfo;

pInfo=NULL;

// find list

{

int i;

string listFlag;

for(i=readPos+8;i<fileLen;)

{

memset(buf,0,5);

aviFile.read(buf, 4); 

cout<<" buf: "<<buf<<endl; 

listFlag=buf;

if(0==listFlag.compare(0,4,"LIST"))

{

// len

dwValue=0;

aviFile.read((char *)&dwValue,4);

i+=4; 

cout<<" len: "<<dwValue<<endl;

// type

memset(buf,0,5);

aviFile.read(buf,4);

i+=4; 

cout<<" type: "<<buf<<endl; 

listFlag=buf;

aviFile.seekg(dwValue-4,ios::cur);

if(0==listFlag.compare(0,4,"movi"))

{

moviPos=aviFile.tellg();

moviPos=moviPos-dwValue+4;

break;

}

}

else if(0==listFlag.compare(0,4,"JUNK"))

{

// len

dwValue=0;

aviFile.read((char *)&dwValue,4);

cout<<" len: "<<dwValue<<endl;

aviFile.seekg(dwValue,ios::cur);

}

i+=4; 

}

}

if(0==moviPos) return -1;

cout<<endl<< " ========= idxl info ==========="<<endl;

// idxl

memset(buf,0,5);

aviFile.read(buf,4);

cout<<" idxl: "<<buf<<endl; 

// avih Len-4字节

dwValue=0;

aviFile.read((char *)&dwValue,4);

cout<<" idxl len: "<<dwValue<<endl;

// avi file index

AVI_IDX *pIndx=new AVI_IDX[frameCount];

char *pszBuf = new char[1024*1024];

DWORD nBufSize = 1024*1024;

// open video file

ofstream videoFile;

videoFile.open("test.video",ios::out | ios::binary);

if(dwValue>=frameCount*sizeof(AVI_IDX))

dwValue=frameCount*sizeof(AVI_IDX);

aviFile.read((char *)pIndx,dwValue); 

{

int idx;

for(idx=0;idx<frameCount;++idx)

//for(idx=0;idx<50;++idx)

{

//memset(buf,0,5);

//memcpy(buf,pIndx[idx].chunk_id,4);

// cout<< endl<< "  id:" <<  buf << endl;

// cout<< "  key:" <<  pIndx[idx].is_key << endl;

// cout<< "  pos:" <<  pIndx[idx].pos << endl;

// cout<< "  size:" <<  pIndx[idx].size << endl;

aviFile.seekg(moviPos+pIndx[idx].pos,ios::beg);

memset(pszBuf,0,nBufSize);

aviFile.read(pszBuf,pIndx[idx].size); 

if(!strncmp(pIndx[idx].chunk_id,"00dc",4));

videoFile.write(pszBuf,pIndx[idx].size);

}

}

delete []pIndx;

pIndx=NULL;

delete []pszBuf;

pszBuf=NULL;

videoFile.close();

aviFile.close();

return 0;

}

五、打印信息

注：本文用例测试H264编码格式AVI文件正常，解封转后保存的h264视频文件用vlc能够正常播放。

vlc播放h264文件需要做下设置：