利用ffmpeg修改的音频图片提取接口

 由于实验室是做图像与视频处理的，所以基本上是利用OpenCV开源库。OpenCV库非常方便，也很好用。但是其底层提供的视频接口不是很多，主要是提取视频帧，后续的都变成图像处理的工作了。在做算是自己的论文方向题目的时候，需要用到音频特征（提取的特征越多，识别的效果应该会有所提升），这时候OpenCV就不行了。由于OpenCV底层的图像和视频接口都是也是使用ffmpeg处理，不过用于比较少而已。所以就花了一点时间看了一些ffmpeg的资料，写了下面的图片音频接口，从而算是对OpenCV的一点点扩展。

接口包括六个文件，分别如下：

FFmpeg.h和FFmpeg.cpp : 接口头文件，并提供通用的全局函数

FFAudio.h和FFAudio.cpp :  利用ffmpeg修改的音频提取接口类，并提供简单的音频特征提取函数接口

FFCapture.h和FFCapture.cpp ： 利用ffmepg修改的视频帧提取接口类，采用OpenCV图片IplImage输出结构。

使用前，需首先配置完成ffmpeg和OpenCV，这个就不在这里说了。

具体代码如下所示：

ffmpeg文件

#ifndef FFMPEG_H#define FFMPEG_H#include <iostream>#include <string.h>#include <fstream>#include <stdio.h>using namespace std;//OpenCV头文件#include "cv.h"#include "highgui.h"//ffmpeg头文件extern "C" {#include "libavformat/avformat.h"#include "libavcodec/avcodec.h"#include "libswscale/swscale.h"}//数据类型定义typedef unsigned short  WORD;//16位无符号整型数typedef unsigned long  DWORD;//32位无符号整型数//定义的全局函数//初始化ffmpeg环境,在使用各种与ffmpeg有关的函数时，需先执行该函数，可在系统初始时调用bool InitFFmpeg();//分数转换为小数double RationalToDouble(AVRational r);//AVFrame格式在RGB24颜色空间转换为IplImage格式void AVFrameToIplImage(AVFrame* pSrcFrame, IplImage* pDstImg);#endif 

#include "FFmpeg.h"//初始化ffmpeg环境bool InitFFmpeg(){//注册视频格式av_register_all();return true;}//分数转换为小数double RationalToDouble(AVRational r){return r.num == 0 || r.den == 0 ? 0. : (double)r.num / (double)r.den;}//AVFrame格式在RGB24颜色空间转换为IplImage格式void AVFrameToIplImage(AVFrame* pSrcFrame, IplImage* pDstImg){//pSrcFrmae指针为空或pSrcFrame图像格式不是RGB24if (NULL == pSrcFrame || NULL == pDstImg || pSrcFrame->format != PIX_FMT_BGR24 || pDstImg->nChannels != 3){return;}cvZero(pDstImg);//根据pFrame信息对pImg进行参数赋值pDstImg->dataOrder = 0; //图像的顶点位置为左上pDstImg->widthStep = pSrcFrame->linesize[0]; //图像的行宽pDstImg->imageSize = pDstImg->height * pSrcFrame->linesize[0];  //图像大小//图像原始数据赋值uchar* ptrImg = NULL;uchar* ptrFrame = NULL;for (int i = 0; i < pDstImg->height; i++){ptrImg = (uchar*)(i * pDstImg->widthStep + pDstImg->imageData);ptrFrame = (uchar*)(i * pSrcFrame->linesize[0] + pSrcFrame->data[0]);for (int j = 0; j < pDstImg->width; j++){ptrImg[j * 3] = ptrFrame[j * 3];ptrImg[j * 3 + 1] = ptrFrame[j * 3 + 1];ptrImg[j * 3 + 2] = ptrFrame[j * 3 + 2];}}}

FFAudio文件

#ifndef FFAUDIO_H#define FFAUDIO_H#include "FFmpeg.h"//wave文件头格式参数//关于下述各个结构体的参数意义，请参考WAV文件具体格式//推荐网址：http://blog.csdn.net/zhihu008/article/details/7854533typedef struct RIFFChunk{char szRiffID[4];   DWORD dwRiffSize;  char szRiffFormat[4];};typedef struct PCMWAVEFORMAT{WORD wFormatTag;           //编码格式WORD wChannels;            //声道数DWORD dwSamplePerSec;      //采样频率DWORD dwAvgBytesPerSec;    //每秒的数据量WORD wBlockAlign;          //块对齐WORD wBitsPerSample;       //wave文件的采样大小};typedef struct FORMATChunk{char szFmtID[4];DWORD dwFmtSize;PCMWAVEFORMAT wavFmt;};typedef struct DATAChunk{char szDataID[4];DWORD dwDataSize;};//利用ffmpeg构造的音频类，用于处理并提取各种音频特征class CFFAudio{private:short* m_pData;//音频原始PCM数据int64_t m_nLength;//音频数据长度，以 sizeof(short) 为单位int m_nChannels;//音频声道数int m_nSampleRate;//音频采样率int m_nBytesPerSample;//音频采样位数//音频帧的属性int m_nSamplePerFrame;//单个音频帧的采样点个数int m_nOverlapPerFrame;//音频帧之间重叠采样点个数int m_nFrameNum;//音频帧个数short** m_pFrameData;//音频帧数据，每行表示一个音频帧bool m_bIsExtracted;//是否已经提取特征,用于避免多次计算提取int m_nAENum;//帧短时能量大于段能量的音频帧个数int m_nZCRNum;//帧过零率大于段过零率的音频帧个数protected:void ChangeToFrame();//对音频信号进行分帧处理float CalcSTEnergy(short* pFrame);//计算单个音频帧的平均短时能量float CalcZCRate(short* pFrame);//计算单个音频帧的短时平均过零率public:CFFAudio(void);//依据参数创建bool CreateFFAudio(short* pData, int64_t nLength, int nChannels, int nSampleRate, AVSampleFormat nSampleFmt);bool LoadWAVFile(char* szFileName);//导入WAV格式文件bool SaveAsWAVFile(char* szFileName);//将PCM数据保存为WAV文件格式void Save(char* szFileName);int64_t GetLength();//获取长度int64_t GetFrameNums();short GetSampleData(int64_t nPos);//获取单个采样点数据short* GetAudioData();//获取音频数据bool ExtractFeature(int& nAENum, int& nZCRNum);//提取特征，包括短时能量与短时平均过零率virtual ~CFFAudio(void);};#endif

#include "FFAudio.h"CFFAudio::CFFAudio(void){m_pData = NULL;m_nLength = -1;m_nChannels = -1;m_nSampleRate = -1;m_nBytesPerSample = -1;m_nSamplePerFrame = -1;m_nOverlapPerFrame = -1;m_nFrameNum = -1;m_pFrameData = NULL;m_bIsExtracted = false;m_nZCRNum = 0;m_nAENum = 0;}CFFAudio::~CFFAudio(void){if (NULL != m_pData){free(m_pData);}for (int i = 0; i < m_nFrameNum; i++){free(m_pFrameData[i]);}free(m_pFrameData);}bool CFFAudio::CreateFFAudio(short* pData, int64_t nLength, int nChannels, int nSampleRate, AVSampleFormat nSampleFmt){//音频PCM数据为空if (NULL == pData || nLength <= 0){return false;}//仅支持单通道与双通道两种声道音频if (nChannels <=0 || nChannels > 2){return false;}//仅支持无符号8位与有符号16位两种采样格式if (nSampleFmt == AV_SAMPLE_FMT_S16){m_nBytesPerSample = 16;//采样位数为16}else if (nSampleFmt == AV_SAMPLE_FMT_U8){m_nBytesPerSample = 8;//采样位数为8}else{return false;}//支持的采样率int nSupportSampleRateArr[] = {6000, 8000, 11025, 16000, 22050, 32000, 32075, 44100, 48000, 96000};bool bFlag = false;for (int i = 0; i < 10; i++){if (nSupportSampleRateArr[i] == nSampleRate){bFlag = true;break;}}if (!bFlag)//输入采样率不属于以上10种，即不支持该采样率{return false;}else{m_nSampleRate = nSampleRate;}//参数数据赋值m_pData = (short*)malloc(nLength * sizeof(short));memcpy(m_pData ,pData, nLength * sizeof(short));m_nLength = nLength;m_nChannels = nChannels;m_nSampleRate = nSampleRate;return true;}bool CFFAudio::LoadWAVFile(char* szFileName){//音频数据已经存在，无法导入if (NULL != m_pData && m_nLength > 0){return false;}//文件名为NULLif (NULL == szFileName){return false;}//验证文件类型是否正确,即文件名最后四位是否为".wav"或".WAV"char szFileType[5] = {0};strncpy(szFileType, szFileName + strlen(szFileName) - 4, 4);if (strcmp(szFileType, ".wav") != 0 && strcmp(szFileType, ".WAV") != 0){return false;}//解析WAV数据文件return false;}bool CFFAudio::SaveAsWAVFile(char* szFileName){//音频数据为NULLif (NULL == m_pData || m_nLength <= 0){return false;}//文件名为NULLif (NULL == szFileName){return false;}//验证文件类型是否正确,即文件名最后四位是否为".wav"或".WAV"char szFileType[5] = {0};strncpy(szFileType, szFileName + strlen(szFileName) - 4, 4);if (strcmp(szFileType, ".wav") != 0 && strcmp(szFileType, ".WAV") != 0){return false;}//构造DATADATAChunk data;strncpy(data.szDataID, "data", 4);data.dwDataSize = m_nLength * sizeof(short);//构造FORMATFORMATChunk fmt;strncpy(fmt.szFmtID, "fmt   ", 4);fmt.dwFmtSize = sizeof(PCMWAVEFORMAT);//构造PCMWAVFORMATfmt.wavFmt.wFormatTag = 1;fmt.wavFmt.wChannels = m_nChannels;fmt.wavFmt.dwSamplePerSec = m_nSampleRate;fmt.wavFmt.dwAvgBytesPerSec = m_nSampleRate * m_nChannels * m_nBytesPerSample / 8;fmt.wavFmt.wBlockAlign = m_nBytesPerSample / 8;fmt.wavFmt.wBitsPerSample = m_nBytesPerSample;//构造RIFFRIFFChunk riff;strncpy(riff.szRiffID, "RIFF", 4);strncpy(riff.szRiffFormat, "WAVE", 4);riff.dwRiffSize = 44 + m_nLength * sizeof(short);//C++的文件输出格式不合适，故改用CFILE* fp = fopen(szFileName, "wb+");fwrite(&riff, sizeof(RIFFChunk), 1, fp);fwrite(&fmt, sizeof(FORMATChunk), 1, fp);fwrite(&data, sizeof(DATAChunk), 1, fp);fwrite(m_pData, m_nLength * sizeof(short), 1, fp);fclose(fp);return true;}void CFFAudio::Save(char* szFileName){ofstream fout;fout.open(szFileName, ios::out | ios::app);for (int i = 0; i < m_nLength; i++){fout<<m_pData[i]<<endl;}fout.close();}int64_t CFFAudio::GetLength(){return m_nLength;}int64_t CFFAudio::GetFrameNums(){return m_nFrameNum;}short CFFAudio::GetSampleData(int64_t nPos){if (nPos < 0 || nPos >= m_nLength){//nPos参数位置错误，返回short能表示的最小值return SHRT_MIN;}else{return m_pData[nPos];}}short* CFFAudio::GetAudioData(){if (NULL == m_pData || m_nLength <= 0){return NULL;}short* pData = (short*)malloc(m_nLength * sizeof(short));memcpy(pData, m_pData, m_nLength * sizeof(short));return pData;}//音频分帧操作void CFFAudio::ChangeToFrame(){//默认以25ms作为音频帧的时长,即单帧的长度 = 采样率 / 40;//相邻两帧之间重叠10ms的长度，即重叠的长度 = 采样率 / 100;m_nSamplePerFrame = m_nSampleRate / 40;m_nOverlapPerFrame = m_nSampleRate / 100;m_nFrameNum = (m_nLength - m_nSamplePerFrame) / (m_nSamplePerFrame - m_nOverlapPerFrame);//音频帧的长度，最后不足一帧的不考虑//依次分帧m_pFrameData = (short**)malloc(sizeof(short*) * m_nFrameNum);for (int i = 0; i < m_nFrameNum; i++){m_pFrameData[i] = (short*)malloc(sizeof(short) * m_nSamplePerFrame);//依次提取单帧数据strncpy((char*)m_pFrameData[i], (char*)(m_pData + i * (m_nSamplePerFrame - m_nOverlapPerFrame)), m_nSamplePerFrame * sizeof(short));}}//备注：在对音频信息进行特征提取的时候，通常会对音频信号进行加窗处理，这里为快速提取，故不进行加窗处理//计算单个音频帧的平均短时能量float CFFAudio::CalcSTEnergy(short* pFrame){if (NULL == pFrame){return -1;}long nEnergy = 0;for (int i = 0; i < m_nSamplePerFrame; i++){nEnergy += pFrame[i] * pFrame[i];}return nEnergy * 1.0 / m_nSamplePerFrame;}//计算单个音频帧的平均过零率float CFFAudio::CalcZCRate(short* pFrame){if (NULL == pFrame){return -1;}int nCount = 0;for (int i = 0; i < m_nSamplePerFrame; i++){if (pFrame[i] >= 0){nCount++;}}return nCount * 1.0 / m_nSamplePerFrame;}bool CFFAudio::ExtractFeature(int& nAENum, int& nZCRNum){if (m_bIsExtracted){nAENum = m_nAENum;nZCRNum = m_nZCRNum;return true;}//对音频数据分帧操作ChangeToFrame();//判断分帧操作是否正确if (NULL == m_pFrameData){return false;}for (int i = 0; i < m_nFrameNum; i++){if (NULL == m_pFrameData[i]){return false;}}//对分帧后的音频帧依次提取短时能量和过零率float* pSTE = new float[m_nFrameNum];float* pZCR = new float[m_nFrameNum];float fSTEMean = 0;//音频帧的平均短时能量float fZCRMean = 0;//音频帧的平均过零率for (int i = 0; i < m_nFrameNum; i++){pSTE[i] = CalcSTEnergy(m_pFrameData[i]);pZCR[i] = CalcZCRate(m_pFrameData[i]);fSTEMean += pSTE[i];fZCRMean += pZCR[i];}fSTEMean /= m_nFrameNum;fZCRMean /= m_nFrameNum;m_nZCRNum = 0;m_nAENum = 0;for (int i = 0; i < m_nFrameNum; i++){if (pSTE[i] > fSTEMean){m_nAENum++;}if (pZCR[i] > fZCRMean){m_nZCRNum++;}}m_bIsExtracted = true;nAENum = m_nAENum;nZCRNum = m_nZCRNum;}

FFCapture文件

#ifndef FFCAPTURE_H#define FFCAPTURE_H#include "FFmpeg.h"#include "FFAudio.h"//利用ffmpeg封装的视频音频处理类，与OpenCV的CvCapture功能基本类似，增加了音频数据提取class CFFCapture{private:char m_szFileName[100];//视频文件路径AVFormatContext* m_pFormatCtx;int m_nVideoStream;//视频流位置int m_nAudioStream;//音频流位置AVCodecContext* m_pVideoCodecCtx;AVCodecContext* m_pAudioCodecCtx;AVCodec* m_pVideoCodec;AVCodec* m_pAudioCodec;uint8_t* m_pVideoBuffer;//帧图像缓冲区AVPacket m_packet;//数据包int m_nFramePos;//当前帧位置AVFrame* m_pFrame;//当前帧图像AVFrame* m_pFrameRGB;//当前帧图像RGB格式数据IplImage* m_pImgRGB;//当前帧图像的OpenCV数据格式//视频流属性int64_t m_nFrameNums;//视频帧总数int64_t m_nDuration;//视频时长，以毫秒为单位double m_dVideoFPS;//视频帧率，用于计算视频帧时间戳//音频流属性int m_nAudioChannels;//音频声道数int m_nSampleRate;//音频采样率AVSampleFormat m_nSampleFmt;//音频采样格式protected:bool GrabFrame();//抓取一帧图像bool SetFramePos(int64_t nPos);//设置视频帧位置short* QueryAudio(int64_t nStartPos, int64_t nStopPos, int64_t& nAudioLength);//获取一段时间内的音频信号,返回音频数据public:CFFCapture(void);bool CreateFFCapture(char* szFileName);//根据视频文件路径名称，创建视频处理对象virtual ~CFFCapture(void);IplImage* QueryFrame();//获取下一帧图像IplImage* QueryFrame(int64_t nPos);//获取特定位置的一帧图像，并设定当前帧位置CFFAudio* QueryAudio(int64_t nStartPos, int64_t nStopPos);//获取一段时间内的音频信号，返回自定义的音频类int GetFramePos();//获取视频帧当前位置int64_t GetVideoDuration();//获取视频时长，以毫秒为单位int64_t GetFrameNums();//获取视频帧数CvSize GetFrameSize();//获取视频图像大小int GetAudioChannels();//获取音频声道数int GetAudioSampleRate();//获取音频采样率AVSampleFormat GetAudioSampleFmt();//获取音频采样格式};#endif

#include "FFCapture.h"CFFCapture::CFFCapture(void){strcpy(m_szFileName, "");m_pFormatCtx = NULL;m_nVideoStream = -1;m_nAudioStream = -1;m_pVideoCodecCtx = NULL;m_pAudioCodecCtx = NULL;m_pVideoCodec = NULL;m_pAudioCodec = NULL;m_pVideoBuffer = NULL;m_nFramePos = -1;m_pFrame = NULL;m_pFrameRGB = NULL;m_nAudioChannels = -1;m_nSampleRate = -1;m_nSampleFmt = AV_SAMPLE_FMT_NONE;}CFFCapture::~CFFCapture(void){if (NULL != m_pVideoBuffer){av_free(m_pVideoBuffer);}if (NULL != m_pFrameRGB){av_free(m_pFrameRGB);}if (NULL != m_pFrame){av_free(m_pFrame);}if (NULL != m_pImgRGB){cvReleaseImage(&m_pImgRGB);}//释放数据包if (m_packet.size > 0){av_free_packet(&m_packet);}// 关闭解码器if (NULL != m_pVideoCodecCtx){avcodec_close(m_pVideoCodecCtx);}if (NULL != m_pAudioCodecCtx){avcodec_close(m_pAudioCodecCtx);}// 关闭视频文件if (NULL != m_pFormatCtx){av_close_input_file(m_pFormatCtx);}}bool CFFCapture::CreateFFCapture(char* szFileName){if (NULL == szFileName){return false;}//打开视频文件if (av_open_input_file(&m_pFormatCtx, szFileName, NULL, 0, NULL) != 0){return false;}strcpy(m_szFileName, szFileName);//文件名保存//获取视频文件流信息if (av_find_stream_info(m_pFormatCtx) < 0){return false;}//寻找视频流与视频流位置for (int i = 0; i < m_pFormatCtx->nb_streams; i++){if (m_pFormatCtx->streams[i]->codec->codec_type == CODEC_TYPE_VIDEO){m_nVideoStream = i;}else if (m_pFormatCtx->streams[i]->codec->codec_type == CODEC_TYPE_AUDIO){m_nAudioStream = i;}}//未寻找到视频流与音频流if (m_nVideoStream == -1 || m_nAudioStream == -1){return false;}//寻找并打开视频流解码格式m_pVideoCodecCtx = m_pFormatCtx->streams[m_nVideoStream]->codec;m_pVideoCodec = avcodec_find_decoder(m_pVideoCodecCtx->codec_id);if (NULL == m_pVideoCodec){return false;}if (avcodec_open(m_pVideoCodecCtx, m_pVideoCodec) < 0){return false;}//获取视频帧数，时长，帧率m_nFrameNums = m_pFormatCtx->streams[m_nVideoStream]->nb_frames;m_nDuration = m_pFormatCtx->streams[m_nVideoStream]->duration;m_dVideoFPS = RationalToDouble(m_pFormatCtx->streams[m_nVideoStream]->r_frame_rate);if (fabs(m_dVideoFPS - 0.00000000001) < 0){m_dVideoFPS = 1.0 / RationalToDouble(m_pVideoCodecCtx->time_base);}//寻找并打开音频流解码格式m_pAudioCodecCtx = m_pFormatCtx->streams[m_nAudioStream]->codec;m_pAudioCodec = avcodec_find_decoder(m_pAudioCodecCtx->codec_id);if (NULL == m_pAudioCodec){return false;}if (avcodec_open(m_pAudioCodecCtx, m_pAudioCodec) < 0){return false;}//获取音频流属性m_nAudioChannels = m_pAudioCodecCtx->channels;//音频声道格式m_nSampleRate = m_pAudioCodecCtx->sample_rate;//音频采样率m_nSampleFmt = m_pAudioCodecCtx->sample_fmt;//音频采样格式//初始化帧图像数据内存等信息m_pFrame = avcodec_alloc_frame();m_pFrameRGB = avcodec_alloc_frame();if (NULL == m_pFrame || NULL == m_pFrameRGB){return false;}m_pVideoBuffer = (uint8_t*)av_malloc(sizeof(uint8_t) * avpicture_get_size(PIX_FMT_RGB24, m_pVideoCodecCtx->width, m_pVideoCodecCtx->height));if (NULL == m_pVideoBuffer){return false;}avpicture_fill((AVPicture*)m_pFrameRGB, m_pVideoBuffer, PIX_FMT_RGB24, m_pVideoCodecCtx->width, m_pVideoCodecCtx->height);//初始化OpenCV图像数据信息m_pImgRGB = cvCreateImage(cvSize(m_pVideoCodecCtx->width, m_pVideoCodecCtx->height), IPL_DEPTH_8U, 3);cvZero(m_pImgRGB);//由于在提取第0个视频帧失败，故提取抓取第0个视频帧IplImage* pImg = QueryFrame();if (NULL != pImg){cvReleaseImage(&pImg);}return true;}bool CFFCapture::GrabFrame(){//循环读取数据帧，直到读取到视频信号帧为止do {if (av_read_frame(m_pFormatCtx, &m_packet) < 0){//读取数据帧失败，可能为数据帧结束return NULL;}} while (m_packet.stream_index != m_nVideoStream);return true;}IplImage* CFFCapture::QueryFrame(){//抓取一个视频数据包GrabFrame();//成功读取视频信号帧，当前视频帧位置加一m_nFramePos++;int nFrameFinished = 0;//视频解码成功标志//视频帧解码avcodec_decode_video(m_pVideoCodecCtx, m_pFrame, &nFrameFinished, m_packet.data, m_packet.size);if (nFrameFinished) //视频帧解码成功{//设置图像转换上下文SwsContext* pSwsCtx = sws_getContext (m_pVideoCodecCtx->width, m_pVideoCodecCtx->height, m_pVideoCodecCtx->pix_fmt, m_pVideoCodecCtx->width, m_pVideoCodecCtx->height, PIX_FMT_BGR24, SWS_BICUBIC, NULL, NULL, NULL); //转换图像格式，将解压出来的YUV420P的图像转换为BRG24的图像sws_scale(pSwsCtx, m_pFrame->data, m_pFrame->linesize, 0, m_pVideoCodecCtx->height, m_pFrameRGB->data, m_pFrameRGB->linesize); //设置数据m_pFrameRGB->width = m_pVideoCodecCtx->width;m_pFrameRGB->height = m_pVideoCodecCtx->height;m_pFrameRGB->format = PIX_FMT_BGR24;//释放图像转换上下文sws_freeContext(pSwsCtx);//输出OpenCV支持的图像帧格式AVFrameToIplImage(m_pFrameRGB, m_pImgRGB);return m_pImgRGB;}else{return NULL;}}//获取特定位置的一帧图像，并设定当前帧位置IplImage* CFFCapture::QueryFrame(int64_t nPos){if (nPos < 0 || nPos >= m_nFrameNums){return NULL;}if (!SetFramePos(nPos)){return NULL;}int nFrameFinished = 0;//视频解码成功标志//视频帧解码avcodec_decode_video(m_pVideoCodecCtx, m_pFrame, &nFrameFinished, m_packet.data, m_packet.size);if (nFrameFinished) //视频帧解码成功{//设置图像转换上下文SwsContext* pSwsCtx = sws_getContext(m_pVideoCodecCtx->width, m_pVideoCodecCtx->height, m_pVideoCodecCtx->pix_fmt, m_pVideoCodecCtx->width, m_pVideoCodecCtx->height, PIX_FMT_BGR24, SWS_BICUBIC, NULL, NULL, NULL); //转换图像格式，将解压出来的YUV420P的图像转换为BRG24的图像sws_scale(pSwsCtx, m_pFrame->data, m_pFrame->linesize, 0, m_pVideoCodecCtx->height, m_pFrameRGB->data, m_pFrameRGB->linesize); //设置当前帧位置m_nFramePos = nPos;//设置数据m_pFrameRGB->width = m_pVideoCodecCtx->width;m_pFrameRGB->height = m_pVideoCodecCtx->height;m_pFrameRGB->format = PIX_FMT_BGR24;//释放图像转换上下文sws_freeContext(pSwsCtx);//输出OpenCV支持的图像帧格式AVFrameToIplImage(m_pFrameRGB, m_pImgRGB);return m_pImgRGB;}else{//解码失败return NULL;}}short* CFFCapture::QueryAudio(int64_t nStartPos, int64_t nStopPos, int64_t& nAudioLength){//判断查询音频位置是否正确if (nStartPos >= nStopPos){return NULL;}nStartPos = nStopPos < 0 ? 0 : nStartPos;nStopPos = nStopPos > m_nFrameNums ? m_nFrameNums : nStopPos;int nMaxSize = AVCODEC_MAX_AUDIO_FRAME_SIZE;//单个音频帧缓存大小short* pAudioBuffer = (short*)malloc(nMaxSize);//单个音频帧缓存指针short* pAudioResult = (short*)malloc(nMaxSize * (nStopPos - nStartPos));//查询结果音频指针（多个音频帧）int nSize = 0;//实际提取单个音频帧大小nAudioLength = 0;//音频结果长度,以 sizeof(short) 为单位int nFramePosCp = m_nFramePos;//原始视频帧位置，提取音频后需将视频帧跳转到原来位置if (NULL == pAudioBuffer || NULL == pAudioResult){return NULL;}//视频流与音频流在时间有一定的偏差，但不影响这里的音频段特征提取，故使用视频帧的位置来定位音频段//设置开始位置if (!SetFramePos(nStartPos)){return NULL;}//依次提取音频while (m_nFramePos != nStopPos){if (av_read_frame(m_pFormatCtx, &m_packet) < 0){return NULL;}if (m_packet.stream_index == m_nAudioStream) //当前提取到音频流{nSize = AVCODEC_MAX_AUDIO_FRAME_SIZE * 100;if (avcodec_decode_audio2(m_pAudioCodecCtx, pAudioBuffer, &nSize, m_packet.data, m_packet.size) < 0){//音频解码失败，返回NULLreturn NULL;}if (nSize <= 0){//音频解码失败，返回NULLreturn NULL;}//保存当前提取音频memcpy(pAudioResult + nAudioLength, pAudioBuffer, nSize);nAudioLength += nSize / sizeof(short);}else if (m_packet.stream_index == m_nVideoStream)//当前提取到视频流{//更显视频帧位置m_nFramePos++;}}free(pAudioBuffer);//将视频帧跳转回原先位置SetFramePos(nFramePosCp);return pAudioResult;}CFFAudio* CFFCapture::QueryAudio(int64_t nStartPos, int64_t nStopPos){int64_t nAudioLength = -1;short* pAudioData = QueryAudio(nStartPos, nStopPos, nAudioLength);if (NULL != pAudioData && nAudioLength > 0){CFFAudio* pAudio = new CFFAudio();if (pAudio->CreateFFAudio(pAudioData, nAudioLength, m_nAudioChannels, m_nSampleRate, m_nSampleFmt)){free(pAudioData);return pAudio;}else{free(pAudioData);return NULL;}}else{free(pAudioData);return NULL;}}int CFFCapture::GetFramePos(){return m_nFramePos;}//设置视频帧位置bool CFFCapture::SetFramePos(int64_t nPos){if (nPos < 0 || m_nFrameNums < 0){return false;}//若nPos大于帧总数，则取帧总数nPos = nPos >= m_nFrameNums ? m_nFrameNums : nPos;//根据视频帧位置近似计算时间戳int nDelta = 16;//定位提前的长度int64_t nStartTime = (int64_t)((nPos - nDelta) * 1.0 / m_dVideoFPS * 1000000);nStartTime = nStartTime > 0 ? nStartTime : 0;if (av_seek_frame(m_pFormatCtx, -1, nStartTime, AVSEEK_FLAG_BACKWARD) >= 0){//清除解码器缓冲avcodec_flush_buffers(m_pVideoCodecCtx);int nFrameFinished = 0;//解码标志//依次抓取视频帧，直到出现正常pts为止while(GrabFrame()){//解码，填充解码器信息avcodec_decode_video(m_pVideoCodecCtx, m_pFrame, &nFrameFinished, m_packet.data, m_packet.size);if (m_packet.pts != AV_NOPTS_VALUE){m_nFramePos = m_packet.pts;break;}}//判断当前帧位置是否等于定位的位置while (m_nFramePos <= nPos - 1){//依次抓取下一帧视频图像数据if (!GrabFrame()){return false;}else{//解码，填充解码器信息avcodec_decode_video(m_pVideoCodecCtx, m_pFrame, &nFrameFinished, m_packet.data, m_packet.size);//视频帧抓取成功，更新当前视频帧位置m_nFramePos++;}}return true;}else{return false;}}//获取视频帧数int64_t CFFCapture::GetFrameNums(){return m_nFrameNums;}//获取视频帧图像大小CvSize CFFCapture::GetFrameSize(){return cvSize(m_pVideoCodecCtx->width, m_pVideoCodecCtx->height);}int CFFCapture::GetAudioChannels(){return m_nAudioChannels;}AVSampleFormat CFFCapture::GetAudioSampleFmt(){return m_nSampleFmt;}int CFFCapture::GetAudioSampleRate(){return m_nSampleRate;}

最后提供使用方法示例

#include <stdio.h>#include "FFmpeg.h"#include "FFCapture.h"#include "FFAudio.h"void main(){InitFFmpeg();CFFCapture* pCapture = new CFFCapture();if (!pCapture->CreateFFCapture("E:\\videos\\Swi_Fra1.avi")){printf("1\n");}printf("%d\n", pCapture->GetFrameNums());CFFAudio* pAudio1 = pCapture->QueryAudio(17417, 18071);CFFAudio* pAudio2 = pCapture->QueryAudio(23121, 23256);CFFAudio* pAudio3 = pCapture->QueryAudio(23257, 23489);CFFAudio* pAudio4 = pCapture->QueryAudio(35826, 35893);CFFAudio* pAudio5 = pCapture->QueryAudio(40831, 40971);CFFAudio* pAudio6 = pCapture->QueryAudio(45944, 46235);CFFAudio* pAudio7 = pCapture->QueryAudio(57345, 57433);pAudio1->Save("正样本3.txt");pAudio2->Save("正样本4.txt");pAudio3->Save("正样本5.txt");pAudio4->Save("正样本6.txt");pAudio5->Save("正样本7.txt");pAudio6->Save("正样本8.txt");pAudio7->Save("正样本9.txt");pAudio1->SaveAsWAVFile("正样本3.wav");pAudio2->SaveAsWAVFile("正样本4.wav");pAudio3->SaveAsWAVFile("正样本5.wav");pAudio4->SaveAsWAVFile("正样本6.wav");pAudio5->SaveAsWAVFile("正样本7.wav");pAudio6->SaveAsWAVFile("正样本8.wav");pAudio7->SaveAsWAVFile("正样本9.wav");CFFAudio* pAudioy1 = pCapture->QueryAudio(1, 631);CFFAudio* pAudioy2 = pCapture->QueryAudio(631, 684);CFFAudio* pAudioy3 = pCapture->QueryAudio(684, 1074);CFFAudio* pAudioy4 = pCapture->QueryAudio(4089, 4152);CFFAudio* pAudioy5 = pCapture->QueryAudio(4343, 4401);CFFAudio* pAudioy6 = pCapture->QueryAudio(4667, 4759);CFFAudio* pAudioy7 = pCapture->QueryAudio(42984, 43034);pAudioy1->Save("负样本3.txt");pAudioy2->Save("负样本4.txt");pAudioy3->Save("负样本5.txt");pAudioy4->Save("负样本6.txt");pAudioy5->Save("负样本7.txt");pAudioy6->Save("负样本8.txt");pAudioy7->Save("负样本9.txt");pAudioy1->SaveAsWAVFile("负样本3.wav");pAudioy2->SaveAsWAVFile("负样本4.wav");pAudioy3->SaveAsWAVFile("负样本5.wav");pAudioy4->SaveAsWAVFile("负样本6.wav");pAudioy5->SaveAsWAVFile("负样本7.wav");pAudioy6->SaveAsWAVFile("负样本8.wav");pAudioy7->SaveAsWAVFile("负样本9.wav");/*pAudio1->SaveAsWAVFile("正样本1.wav");pAudio2->SaveAsWAVFile("正样本2.wav");int nAENum = 0;int nZCRNum = 0;ofstream fout;fout.open("音频特征.txt", ios::out | ios::app);fout<<"正样本:\n";pAudio1->ExtractFeature(nAENum, nZCRNum);fout<<"1号样本："<<nAENum * 1.0 / pAudio1->GetFrameNums()<<"    "<<nZCRNum * 1.0 / pAudio1->GetFrameNums()<<"    "<<pAudio1->GetFrameNums()<<endl;pAudio2->ExtractFeature(nAENum, nZCRNum);fout<<"2号样本："<<nAENum * 1.0 / pAudio2->GetFrameNums()<<"    "<<nZCRNum * 1.0 / pAudio2->GetFrameNums()<<"    "<<pAudio2->GetFrameNums()<<endl;*//*CFFAudio* pAudio6 = pCapture->QueryAudio(16, 286);CFFAudio* pAudio7 = pCapture->QueryAudio(1218, 1257);pAudio6->Save("负样本1.txt");pAudio7->Save("负样本2.txt");pAudio6->SaveAsWAVFile("负样本1.wav");pAudio7->SaveAsWAVFile("负样本2.wav");fout<<"负样本:\n";pAudio6->ExtractFeature(nAENum, nZCRNum);fout<<"1号样本："<<nAENum * 1.0 / pAudio6->GetFrameNums()<<"    "<<nZCRNum * 1.0 / pAudio6->GetFrameNums()<<"    "<<pAudio6->GetFrameNums()<<endl;pAudio7->ExtractFeature(nAENum, nZCRNum);fout<<"2号样本："<<nAENum * 1.0 / pAudio7->GetFrameNums()<<"    "<<nZCRNum * 1.0 / pAudio7->GetFrameNums()<<"    "<<pAudio7->GetFrameNums()<<endl;fout.close();*//*//正样本CFFAudio* pAudio1 = pCapture->QueryAudio(751, 1867);CFFAudio* pAudio2 = pCapture->QueryAudio(14213, 15374);CFFAudio* pAudio3 = pCapture->QueryAudio(19704, 22040);CFFAudio* pAudio4 = pCapture->QueryAudio(44839, 46646);CFFAudio* pAudio5 = pCapture->QueryAudio(59913, 61193);pAudio1->SaveAsWAVFile("正样本1.wav");pAudio2->SaveAsWAVFile("正样本2.wav");pAudio3->SaveAsWAVFile("正样本3.wav");pAudio4->SaveAsWAVFile("正样本4.wav");pAudio5->SaveAsWAVFile("正样本5.wav");int nAENum = 0;int nZCRNum = 0;ofstream fout;fout.open("音频特征.txt", ios::out | ios::app);fout<<"正样本:\n";pAudio1->ExtractFeature(nAENum, nZCRNum);fout<<"1号样本："<<nAENum * 1.0 / pAudio1->GetFrameNums()<<"    "<<nZCRNum * 1.0 / pAudio1->GetFrameNums()<<"    "<<pAudio1->GetFrameNums()<<endl;pAudio2->ExtractFeature(nAENum, nZCRNum);fout<<"2号样本："<<nAENum * 1.0 / pAudio2->GetFrameNums()<<"    "<<nZCRNum * 1.0 / pAudio2->GetFrameNums()<<"    "<<pAudio2->GetFrameNums()<<endl;pAudio3->ExtractFeature(nAENum, nZCRNum);fout<<"3号样本："<<nAENum * 1.0 / pAudio3->GetFrameNums()<<"    "<<nZCRNum * 1.0 / pAudio3->GetFrameNums()<<"    "<<pAudio3->GetFrameNums()<<endl;pAudio4->ExtractFeature(nAENum, nZCRNum);fout<<"4号样本："<<nAENum * 1.0 / pAudio4->GetFrameNums()<<"    "<<nZCRNum * 1.0 / pAudio4->GetFrameNums()<<"    "<<pAudio4->GetFrameNums()<<endl;pAudio5->ExtractFeature(nAENum, nZCRNum);fout<<"5号样本："<<nAENum * 1.0 / pAudio5->GetFrameNums()<<"    "<<nZCRNum * 1.0 / pAudio5->GetFrameNums()<<"    "<<pAudio5->GetFrameNums()<<endl;//负样本CFFAudio* pAudio6 = pCapture->QueryAudio(4993, 5422);CFFAudio* pAudio7 = pCapture->QueryAudio(6020, 6886);CFFAudio* pAudio8 = pCapture->QueryAudio(8874, 10279);CFFAudio* pAudio9 = pCapture->QueryAudio(41513, 42937);CFFAudio* pAudio10 = pCapture->QueryAudio(55245, 55504);pAudio6->SaveAsWAVFile("负样本1.wav");pAudio7->SaveAsWAVFile("负样本2.wav");pAudio8->SaveAsWAVFile("负样本3.wav");pAudio9->SaveAsWAVFile("负样本4.wav");pAudio10->SaveAsWAVFile("负样本5.wav");fout<<"负样本:\n";pAudio6->ExtractFeature(nAENum, nZCRNum);fout<<"1号样本："<<nAENum * 1.0 / pAudio6->GetFrameNums()<<"    "<<nZCRNum * 1.0 / pAudio6->GetFrameNums()<<"    "<<pAudio6->GetFrameNums()<<endl;pAudio7->ExtractFeature(nAENum, nZCRNum);fout<<"2号样本："<<nAENum * 1.0 / pAudio7->GetFrameNums()<<"    "<<nZCRNum * 1.0 / pAudio7->GetFrameNums()<<"    "<<pAudio7->GetFrameNums()<<endl;pAudio8->ExtractFeature(nAENum, nZCRNum);fout<<"3号样本："<<nAENum * 1.0 / pAudio8->GetFrameNums()<<"    "<<nZCRNum * 1.0 / pAudio8->GetFrameNums()<<"    "<<pAudio8->GetFrameNums()<<endl;pAudio9->ExtractFeature(nAENum, nZCRNum);fout<<"4号样本："<<nAENum * 1.0 / pAudio9->GetFrameNums()<<"    "<<nZCRNum * 1.0 / pAudio9->GetFrameNums()<<"    "<<pAudio9->GetFrameNums()<<endl;pAudio10->ExtractFeature(nAENum, nZCRNum);fout<<"5号样本："<<nAENum * 1.0 / pAudio10->GetFrameNums()<<"    "<<nZCRNum * 1.0 / pAudio10->GetFrameNums()<<"    "<<pAudio10->GetFrameNums()<<endl;fout.close();*/}