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main.cpp文件代码如下：

#include "myplayer.h"#include 
   
    #pragma comment(lib,"avformat.lib")#pragma comment(lib,"avutil.lib")#pragma comment(lib,"avcodec.lib")#pragma comment(lib,"swscale.lib")extern "C"{    #include 
    
         #include 
     
      }static double r2d(AVRational r){	return r.num == 0 || r.den == 0 ? 0. : (double)r.num / (double)r.den;}int main(int argc, char *argv[]){	av_register_all();	char *path = "test.mp4";	AVFormatContext *ac = NULL;	int re = avformat_open_input(&ac, path, 0, 0);		if (re != 0){//打开文件失败		char buf[1024] = { 0 };		av_strerror(re, buf, sizeof(buf));		printf("file %s open failed because of : %s", path, buf);		getchar();		return -1;	}		int totalSec = ac->duration / AV_TIME_BASE;	printf("指定的视频文件有 %d分%d秒\n", totalSec / 60, totalSec % 60);	int videoStream = 0;	AVCodecContext *videoCtx = NULL;	SwsContext *cCtx = NULL;	int outWidth = 640;	int outHeight = 480;	char *rgb = new char[outWidth * outHeight * 4];	for (int i = 0; i < ac->nb_streams; i++)	{		AVCodecContext *enc = ac->streams[i]->codec;				if (enc->codec_type == AVMEDIA_TYPE_VIDEO){			videoStream = i;			videoCtx = enc;			AVCodec *codec = avcodec_find_decoder(enc->codec_id);			if (!codec){				printf("无法解码此视频文件\n");				return -1;			}			int err = avcodec_open2(enc, codec, NULL);			if (err != 0){				char buf[1024] = { 0 };				av_strerror(err, buf, sizeof(buf));				printf(buf);				return -2;			}			printf("\n");			printf("成功打开视频编码流\n");		}	}	AVFrame *yuv = av_frame_alloc();	for (;;){		AVPacket pkt;		re = av_read_frame(ac, &pkt);		if (re != 0){			break;		}		if (pkt.stream_index != videoStream)		{			av_packet_unref(&pkt);			continue;		}		int pts = pkt.pts * r2d(ac->streams[pkt.stream_index]->time_base) * 1000;//得到帧的毫秒值				int re = avcodec_send_packet(videoCtx,&pkt);		if (re != 0){			av_packet_unref(&pkt);			continue;		}		re = avcodec_receive_frame(videoCtx,yuv);		if (re != 0){			av_packet_unref(&pkt);			continue;		}		printf("[D]___");				//打开ffmpeg格式转换和缩放器		cCtx = sws_getCachedContext(cCtx, videoCtx->width, videoCtx->height, videoCtx->pix_fmt,			outWidth, outHeight, AV_PIX_FMT_BGRA, SWS_BICUBIC,			NULL, NULL, NULL);		if (!cCtx){			printf("sws_getCachedContext failed!\n");			break;		}		uint8_t *data[AV_NUM_DATA_POINTERS] = {0};		data[0] = (uint8_t *)rgb;		int linesize[AV_NUM_DATA_POINTERS] = { 0 };		linesize[0] = outWidth * 4;		int h = sws_scale(cCtx, yuv->data, yuv->linesize, 0, videoCtx->height, data, linesize);		if (h > 0){			printf("(%d)", h);		}		printf("pts = %d 毫秒\n", pts);		av_packet_unref(&pkt);	}		if (cCtx){		sws_freeContext(cCtx);		cCtx = NULL;	}	avformat_close_input(&ac);	ac = NULL;	QApplication a(argc, argv);	MyPlayer w;	w.show();	return a.exec();}