ffmpeg rtmp推流代码示例

     rtmp推流，得有rtmp服务器，可以参考这篇博客搭建rtmp服务器  ===》》》ubuntu搭建rtmp服务器，如果自己有rtmp服务器，可以不用看。

     rtmp推流需要用flv格式， 本篇博客demo是本地flv文件rtmp推流. 主要流程如下：

     代码如下：

#include 

extern "C"
{
#include "libavformat/avformat.h"
#include "libavutil/time.h"
}

using namespace std;

#pragma comment(lib,"avformat.lib")
#pragma comment(lib,"avutil.lib")
#pragma comment(lib,"avcodec.lib")

int ff_Error(int errNum)
{
	char buf[1024] = { 0 };
	av_strerror(errNum, buf, sizeof(buf));
	cout << buf << endl;

	return -1;
}

static double r2d(AVRational r)
{
	return r.num == 0 || r.den == 0 ? 0. : (double)r.num / (double)r.den;
}

int main()
{
	char *inUrl = "D:\\TestFiles\\test.flv";
	char *outUrl = "rtmp://192.168.126.134/live";

	av_register_all();

	//初始化网络库
	avformat_network_init();

	AVFormatContext *ictx = NULL;

	//打开文件，解封文件头
	int re = avformat_open_input(&ictx, inUrl, 0, 0);
	if (re != 0)
	{
		return ff_Error(re);
	}

	cout << "open file " << inUrl << " success..." << endl;

	//获取音频视频流信息
	re = avformat_find_stream_info(ictx, 0);
	if (re != 0)
	{
		return ff_Error(re);
	}

	cout << "打印输入文件信息" << endl;
	av_dump_format(ictx, 0, inUrl, 0);
	
	//输出流 
	//创建输出流上下文
	AVFormatContext *octx = NULL;
	re = avformat_alloc_output_context2(&octx, 0, "flv", outUrl);
	if (!octx)
	{
		return ff_Error(re);
	}

	cout << "输出上下文创建成功" << endl;

	//配置输出流
	//遍历输入的AVStream
	for (int i = 0; i < ictx->nb_streams; i++)
	{
		//创建输出流
		AVStream *out = avformat_new_stream(octx, ictx->streams[i]->codec->codec);
		if (!out)
		{
			return ff_Error(0);
		}
		//复制配置信息
		re = avcodec_parameters_copy(out->codecpar, ictx->streams[i]->codecpar);
		out->codec->codec_tag = 0;
	}

	cout << "打印输出流信息" << endl;
	av_dump_format(octx, 0, outUrl, 1);

	//rtmp推流
	//打开io
	re = avio_open(&octx->pb, outUrl, AVIO_FLAG_WRITE);
	
	if (!octx->pb)
	{
		return ff_Error(re);
	}

	//写入头信息
	re = avformat_write_header(octx, 0);
	if (re < 0)
	{
		return ff_Error(re);
	}
	
	AVPacket pkt;
	long long startTime = av_gettime();
	for (;;)
	{
		re = av_read_frame(ictx, &pkt);
		if (re != 0)
		{
			break;
		}

		cout << pkt.pts << " " << flush;

		//计算转换pts dts
		AVRational itime = ictx->streams[pkt.stream_index]->time_base;
		AVRational otime = octx->streams[pkt.stream_index]->time_base;
		pkt.pts = av_rescale_q_rnd(pkt.pts, itime, otime, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_NEAR_INF));
		pkt.dts = av_rescale_q_rnd(pkt.pts, itime, otime, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_NEAR_INF));
		pkt.duration = av_rescale_q_rnd(pkt.duration, itime, otime, (AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_NEAR_INF));
		pkt.pos = -1;

		//视频帧推送速度
		if (ictx->streams[pkt.stream_index]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
		{
			AVRational tb = ictx->streams[pkt.stream_index]->time_base;
			//已经过去的时间
			long long now = av_gettime() - startTime;
			long long dts = 0;
			dts = pkt.dts * (1000 * 1000 * r2d(tb));

			if (dts > now)
				av_usleep(dts - now);
		}
        
        //推送帧数据
		re = av_interleaved_write_frame(octx, &pkt);
		if (re<0)
		{
			return ff_Error(re);
		}
	}

	cout << "rtmp 推流结束" << endl;
	
	return 0;
}

       注意，有些flv视频文件可能会推流失败。

       运行程序后，用VLC拉流，如下：

         推流成功