2.打开codec

#include <iostream>
#include <thread>
extern "C" {
#include "libavutil/avutil.h"
#include "libavcodec/avcodec.h "
#include "libavformat/avformat.h"
}

#pragma comment(lib, "avcodec.lib")
#pragma comment(lib, "avutil.lib")
#pragma comment(lib, "avformat.lib")
#pragma warning(disable:4996)
using namespace std;

//线程sleep c++11
void Xsleep(int ms)
{
	//c++11支持
	chrono::milliseconds du(ms);
	this_thread::sleep_for(du);
}

//防止分母是0 挂掉
static double r2d(AVRational in)
{
	return (in.den == 0) ? 0 : ((double)in.num / (double)in.den);
}

int main()
{
	//avcodec_configuration();
	//初始化封装库
	av_register_all();
	avformat_network_init();

	//注册解码器
	avcodec_register_all();

	const char *path = "zxy10.mp4";
	AVFormatContext *ic = NULL;
	int ret = avformat_open_input(&ic, path, NULL, NULL);
	if (ret != 0)
	{
		char buf[1024] = { 0 };
		av_strerror(ret, buf, sizeof(buf) - 1);
		av_log(NULL, AV_LOG_ERROR, "open file erro %s\n:", buf);
		getchar();
		return -1;
	}
	cout << "open file :" << ic->filename << " success" << endl;

	avformat_find_stream_info(ic, NULL);

	cout << "file time is " << ic->duration / AV_TIME_BASE << endl;

	av_dump_format(ic, 0, path, 0);


	int audioStream = 0;  //记录音频和视频的编号
	int videostream = 0;
#if 0

	{
		//获取音视频
		for (int i = 0; i < ic->nb_streams; i++)
		{
			AVStream *as = ic->streams[i];

			if (as->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)		//视屏
			{
				videostream = i;
				cout << "视频信息 stream :" << videostream << endl;
				cout << "height :" << as->codecpar->height << endl;
				cout << "weith :" << as->codecpar->width << endl;
				cout << "codec_id :" << as->codecpar->codec_id << endl;
				cout << "format :" << as->codecpar->format << endl;
				cout << "frame_size :" << as->codecpar->frame_size << endl;
				cout << "fps : " << r2d(as->avg_frame_rate) << endl;
				//AVPixelFormat;
			}
			else if (as->codecpar->codec_type == AVMEDIA_TYPE_AUDIO)//音频
			{
				audioStream = i;
				cout << endl;
				cout << "音频信息,stream " << audioStream << endl;
				cout << "codec_id :" << as->codecpar->codec_id << endl;
				cout << "channels :" << as->codecpar->channels << endl;
				cout << "sample_rate :" << as->codecpar->sample_rate << endl;
				cout << "format :" << as->codecpar->format << endl;
				cout << "frame_size :" << as->codecpar->frame_size << endl;
				cout << "fps : " << r2d(as->avg_frame_rate) << endl;
				//AVSampleFormat;
			}
		}
	}

#endif
	//下面方法可以替换上面的
	videostream = av_find_best_stream(ic, AVMEDIA_TYPE_VIDEO, -1, -1, NULL, 0);
	if (videostream < 0)
	{
		char buf[1024] = { 0 };
		av_strerror(videostream, buf, sizeof(buf) - 1);
		av_log(NULL, AV_LOG_ERROR, "Not find Video Stream : %s\n:", buf);
		if (ic)
		{
			avformat_close_input(&ic);
		}
		getchar();
		return -1;
	}
	else
	{
		cout << endl;
		cout << "视频信息 stream :" << videostream << endl;
		cout << "height :" << ic->streams[videostream]->codecpar->height << endl;
		cout << "weith :" << ic->streams[videostream]->codecpar->width << endl;
		cout << "codec_id :" << ic->streams[videostream]->codecpar->codec_id << endl;
		cout << "format :" << ic->streams[videostream]->codecpar->format << endl;
		cout << "frame_size :" << ic->streams[videostream]->codecpar->frame_size << endl;
		cout << "fps : " << r2d(ic->streams[videostream]->avg_frame_rate) << endl;
		//AVPixelFormat;
	}
	//获取视频流
	audioStream = av_find_best_stream(ic, AVMEDIA_TYPE_AUDIO, -1, -1, NULL, 0);
	if (audioStream < 0)
	{
		char buf[1024] = { 0 };
		av_strerror(audioStream, buf, sizeof(buf) - 1);
		av_log(NULL, AV_LOG_ERROR, "Not find Audio Stream : %s\n:", buf);
		if (ic)
		{
			avformat_close_input(&ic);
		}
		getchar();
		return -1;
	}
	else
	{
		cout << endl;
		cout << "音频信息,stream " << audioStream << endl;
		cout << "codec_id :" << ic->streams[audioStream]->codecpar->codec_id << endl;
		cout << "channels :" << ic->streams[audioStream]->codecpar->channels << endl;
		cout << "sample_rate :" << ic->streams[audioStream]->codecpar->sample_rate << endl;
		cout << "format :" << ic->streams[audioStream]->codecpar->format << endl;
		cout << "frame_size :" << ic->streams[audioStream]->codecpar->frame_size << endl;
		cout << "fps : " << r2d(ic->streams[audioStream]->avg_frame_rate) << endl;
	}


	打开视频解码器/
	//找到视频解码器,不要在av_find_best_stream里去找解码器,那样耦合性太强了
	AVCodec * vcodec = avcodec_find_decoder(ic->streams[videostream]->codecpar->codec_id);
	if (!vcodec)
	{
		cout << "can not find AVcodec :" << ic->streams[videostream]->codecpar->codec_id << endl;
		cin.get();
		return -1;
	}
	cout << "find avcodec successed : id is" << ic->streams[videostream]->codecpar->codec_id << endl;
	//创建解码器上下 记得释放~
	AVCodecContext * vc = avcodec_alloc_context3(vcodec);

	//复制(配置)解码器上下文参数 
	avcodec_parameters_to_context(vc, ic->streams[videostream]->codecpar);
	vc->thread_count = 16;  //手动指定线程数

	//打开解码器上下文(分配空间给context) 因为vocdec已经被创建了,所以第二个参数传入0
	ret = avcodec_open2(vc, 0, 0);
	if (ret != 0)
	{
		char buf[1024] = { 0 };
		av_strerror(ret, buf, sizeof(buf) - 1);
		av_log(NULL, AV_LOG_ERROR, "avcodec_open2 %s\n:", buf);
		getchar();
		return -1;
	}
	cout << "video avcodec_open2  success!"<<endl;
	///打开视频解码器end//


	打开音频解码器/
	//找到音频解码器,不要在av_find_best_stream里去找解码器,那样耦合性太强了
	AVCodec * acodec = avcodec_find_decoder(ic->streams[audioStream]->codecpar->codec_id);
	if (!acodec)
	{
		cout << "can not find AVcodec :" << ic->streams[audioStream]->codecpar->codec_id << endl;
		cin.get();
		return -1;
	}
	cout << "find avcodec successed : id is" << ic->streams[audioStream]->codecpar->codec_id << endl;
	//创建解码器上下 记得释放~
	AVCodecContext * ac = avcodec_alloc_context3(acodec);

	//复制(配置)解码器上下文参数 
	avcodec_parameters_to_context(ac, ic->streams[audioStream]->codecpar);
	//vc->thread_count = 16;  //手动指定线程数

	//打开解码器上下文(分配空间给context) 因为vocdec已经被创建了,所以第二个参数传入0
	ret = avcodec_open2(ac, 0, 0);
	if (ret != 0)
	{
		char buf[1024] = { 0 };
		av_strerror(ret, buf, sizeof(buf) - 1);
		av_log(NULL, AV_LOG_ERROR, "avcodec_open2 %s\n:", buf);
		getchar();
		return -1;
	}
	cout << "audio avcodec_open2  success!" << endl;
	///打开音频解码器end//

	AVPacket * pkt = av_packet_alloc();
	for (;;)
	{
		int ret = av_read_frame(ic, pkt);
		if (ret != 0)  //有可能是文件读完了;也有可能是出错了
		{
			//{
			//	//seek到3s的位置
			//	int ms = 3000;
			//	long long pos = (double)ms / (double)(r2d(ic->streams[pkt->stream_index]->time_base) * 1000);
			//	av_seek_frame(ic, videostream, pos, AVSEEK_FLAG_BACKWARD | AVSEEK_FLAG_FRAME);
			//}


			break; //失败不需要怎么样,直接跳出循环
		}
		{
			cout << "pkt->size : " << pkt->size << endl;
			//显示的时间
			cout << " pkt->pts :" << pkt->pts << endl;
			//显示的ms
			cout << (double)r2d(ic->streams[pkt->stream_index]->time_base) << endl;
			cout << "pkt->pts ms :" << (pkt->pts) * ((double)r2d(ic->streams[pkt->stream_index]->time_base) * 1000) << endl;
			cout << "pkt->dts :" << pkt->dts << endl;
			if (pkt->stream_index == audioStream)
			{
				cout << "音频:" << endl;
			}
			else if (pkt->stream_index == videostream)
			{
				cout << "图片:" << endl;
			}
		}
		//释放引用计数;为零 清空pkt.buff 指向的空间
		av_packet_unref(pkt);
		Xsleep(500); //sleep 500ms
	}
	av_packet_free(&pkt);

	if (ic)
	{
		avformat_close_input(&ic);
	}
#ifdef _WIN32
	//cout << "windows app" << endl;
#ifdef _WIN64
	//cout << "win64" << endl;
#else
	//cout << "win32" << endl;
#endif // _WIN64
#else
	//cout << " linux" << endl;

#endif //_WIN32


	cin.get();
	return 0;

}