FFMPEG 从rtsp抓取流，转存为flv文件

来源：互联网发布：win32api c语言编辑：程序博客网时间：2024/05/21 21:37
#include<stdio.h>#define __STDC_CONSTANT_MACROS#ifdef __cplusplusextern "C"{#endif#include<libavformat/avformat.h>#include<libavutil/mathematics.h>#include<libavutil/time.h>#ifdef __cplusplus}#endifint main(int argc,char **argv){    AVOutputFormat *ofmt = NULL;    AVFormatContext *ifmt_ctx = NULL,*ofmt_ctx = NULL;    AVPacket pkt;    const char *in_filename,*out_filename;        int ret,i;    int video_index=-1;    int frame_index=0;    in_filename="rtsp://admin:12345@192.168.1.20:554/";    out_filename="receive.flv";    av_register_all();    avformat_network_init();    //使用TCP连接打开RTSP，设置最大延迟时间    AVDictionary *avdic=NULL;      char option_key[]="rtsp_transport";      char option_value[]="tcp";      av_dict_set(&avdic,option_key,option_value,0);      char option_key2[]="max_delay";      char option_value2[]="5000000";      av_dict_set(&avdic,option_key2,option_value2,0);     //打开输入流    if((ret=avformat_open_input(&ifmt_ctx,in_filename,0,&avdic))<0)    {        printf("Could not open input file.\n");        goto end;    }    if((ret=avformat_find_stream_info(ifmt_ctx,0))<0)    {        printf("Failed to retrieve input stream information\n");        goto end;    }    //nb_streams代表有几路流，一般是2路：即音频和视频，顺序不一定    for(i=0;i<ifmt_ctx->nb_streams;i++){                if(ifmt_ctx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO)        {            //这一路是视频流，标记一下，以后取视频流都从ifmt_ctx->streams[video_index]取            video_index=i;            break;        }    }    av_dump_format(ifmt_ctx,0,in_filename,0);    //打开输出流    avformat_alloc_output_context2(&ofmt_ctx,NULL,NULL,out_filename);        if(!ofmt_ctx)    {        printf("Could not create output context\n");        ret=AVERROR_UNKNOWN;        goto end;    }        ofmt = ofmt_ctx->oformat;    for(i=0;i<ifmt_ctx->nb_streams;i++)    {    //根据输入流创建输出流        AVStream *in_stream = ifmt_ctx->streams[i];        AVStream *out_stream = avformat_new_stream(ofmt_ctx,in_stream->codec->codec);        if(!out_stream)        {            printf("Failed allocating output stream.\n");            ret = AVERROR_UNKNOWN;            goto end;        }        //将输出流的编码信息复制到输入流        ret = avcodec_copy_context(out_stream->codec,in_stream->codec);        if(ret<0)        {            printf("Failed to copy context from input to output stream codec context\n");            goto end;        }        out_stream->codec->codec_tag = 0;            if(ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)            out_stream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;    }    //Dump format--------------------    av_dump_format(ofmt_ctx,0,out_filename,1);    //打开输出文件    if(!(ofmt->flags & AVFMT_NOFILE))    {        ret = avio_open(&ofmt_ctx->pb,out_filename,AVIO_FLAG_WRITE);        if(ret<0)        {            printf("Could not open output URL '%s'",out_filename);            goto end;        }    }    //写文件头到输出文件    ret = avformat_write_header(ofmt_ctx,NULL);    if(ret < 0)    {        printf("Error occured when opening output URL\n");        goto end;    }    //while循环中持续获取数据包，不管音频视频都存入文件    while(1)    {        AVStream *in_stream,*out_stream;        //从输入流获取一个数据包        ret = av_read_frame(ifmt_ctx,&pkt);        if(ret<0)            break;        in_stream = ifmt_ctx->streams[pkt.stream_index];        out_stream = ofmt_ctx->streams[pkt.stream_index];        //copy packet        //转换 PTS/DTS 时序        pkt.pts = av_rescale_q_rnd(pkt.pts,in_stream->time_base,out_stream->time_base,(enum AVRounding)(AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));        pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, (enum AVRounding)(AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));          //printf("pts %d dts %d base %d\n",pkt.pts,pkt.dts, in_stream->time_base);        pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);         pkt.pos = -1;          //此while循环中并非所有packet都是视频帧，当收到视频帧时记录一下，仅此而已        if(pkt.stream_index==video_index)        {            printf("Receive %8d video frames from input URL\n",frame_index);            frame_index++;        }        //将包数据写入到文件。        ret = av_interleaved_write_frame(ofmt_ctx,&pkt);        if(ret < 0)        {            /**            当网络有问题时，容易出现到达包的先后不一致，pts时序混乱会导致            av_interleaved_write_frame函数报 -22 错误。暂时先丢弃这些迟来的帧吧            若所大部分包都没有pts时序，那就要看情况自己补上时序（比如较前一帧时序+1）再写入。            */            if(ret==-22){                continue;            }else{                printf("Error muxing packet.error code %d\n" , ret);                break;            }                    }                //av_free_packet(&pkt); //此句在新版本中已deprecated 由av_packet_unref代替        av_packet_unref(&pkt);    }    //写文件尾    av_write_trailer(ofmt_ctx);end:        av_dict_free(&avdic);    avformat_close_input(&ifmt_ctx);    //Close input    if(ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))        avio_close(ofmt_ctx->pb);    avformat_free_context(ofmt_ctx);    if(ret<0 && ret != AVERROR_EOF)    {        printf("Error occured.\n");        return -1;    }    return 0;    }
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