FFmpeg-iOS推流器的简单封装

FFmpeg_allluckly.cn.png

Mac编译ffmpeg获取FFmpeg-iOS
ffmpeg的H.264解码
由上俩篇文章，我们已经对ffmpeg有了一定的了解和应用了，接下来让我们一起学习怎么利用ffmpeg推流。
在推流之前我们需搭建一个本地的nginx推流服务器用来测试。

主要参考的这篇文章 iOS直播app(推流篇)在这里不做过多的阐述，有兴趣的朋友可以跟着做一做。

期间我这边遇到的问题：

Could not symlink share/man/man8/nginx.8
/usr/local/share/man/man8 is not writable.

只要原因是文件夹系统没有权限导致的，解决方法是文件夹前往/usr/local/share/man/man8文件，显示简介设置系统可读可写即可。

我这边配置好的nginx推流服务器的配置文件nginx.conf内容为

#user  nobody;
worker_processes  1;

#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;

#pid        logs/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       mime.types;
    default_type  application/octet-stream;

    #log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
    #                  '$status $body_bytes_sent "$http_referer" '
    #                  '"$http_user_agent" "$http_x_forwarded_for"';

    #access_log  logs/access.log  main;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;

    server {
        listen       8080;
        server_name  localhost;

        #charset koi8-r;

        #access_log  logs/host.access.log  main;

        location / {
            root   html;
            index  index.html index.htm;
        }

        #error_page  404              /404.html;

        # redirect server error pages to the static page /50x.html
        #
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }

        # proxy the PHP scripts to Apache listening on 127.0.0.1:80
        #
        #location ~ \.php$ {
        #    proxy_pass   http://127.0.0.1;
        #}

        # pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
        #
        #location ~ \.php$ {
        #    root           html;
        #    fastcgi_pass   127.0.0.1:9000;
        #    fastcgi_index  index.php;
        #    fastcgi_param  SCRIPT_FILENAME  /scripts$fastcgi_script_name;
        #    include        fastcgi_params;
        #}

        # deny access to .htaccess files, if Apache's document root
        # concurs with nginx's one
        #
        #location ~ /\.ht {
        #    deny  all;
        #}
    }


    # another virtual host using mix of IP-, name-, and port-based configuration
    #
    #server {
    #    listen       8000;
    #    listen       somename:8080;
    #    server_name  somename  alias  another.alias;

    #    location / {
    #        root   html;
    #        index  index.html index.htm;
    #    }
    #}


    # HTTPS server
    #
    #server {
    #    listen       443 ssl;
    #    server_name  localhost;

    #    ssl_certificate      cert.pem;
    #    ssl_certificate_key  cert.key;

    #    ssl_session_cache    shared:SSL:1m;
    #    ssl_session_timeout  5m;

    #    ssl_ciphers  HIGH:!aNULL:!MD5;
    #    ssl_prefer_server_ciphers  on;

    #    location / {
    #        root   html;
    #        index  index.html index.htm;
    #    }
    #}
    include servers/*;

}

rtmp {
    server {
        listen 1991;
        application liveApp {
            live on;
            record off;
        }
    }
}

可整个复制进去。得到的推流服务器地址如下

rtmp://localhost:1991/liveApp/room

如果先前已经做过Mac编译ffmpeg获取FFmpeg-iOS这一步的话，不需要再继续下载ffmpeg。
下面进入我们的代码阶段即可。

- (void)pushFlow:(NSString *)input_str output_str:(NSString *)output_rtmpStr{
    char input_str_full[500]={0};
    char output_str_full[500]={0};
    
//    NSString *input_str= [NSString stringWithFormat:@"resource.bundle/%@",self.input.text];
    NSString *input_nsstr=[[[NSBundle mainBundle]resourcePath] stringByAppendingPathComponent:input_str];
    
    sprintf(input_str_full,"%s",[input_nsstr UTF8String]);
    sprintf(output_str_full,"%s",[output_rtmpStr UTF8String]);
    
    printf("Input Path:%s\n",input_str_full);
    printf("Output Path:%s\n",output_str_full);
    
    AVOutputFormat *ofmt = NULL;
    //Input AVFormatContext and Output AVFormatContext
    AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
    AVPacket pkt;
    char in_filename[500]={0};
    char out_filename[500]={0};
    int ret, i;
    int videoindex=-1;
    int frame_index=0;
    int64_t start_time=0;
    //in_filename  = "cuc_ieschool.mov";
    //in_filename  = "cuc_ieschool.h264";
    //in_filename  = "cuc_ieschool.flv";//Input file URL
    //out_filename = "rtmp://localhost/publishlive/livestream";//Output URL[RTMP]
    //out_filename = "rtp://233.233.233.233:6666";//Output URL[UDP]
    
    strcpy(in_filename,input_str_full);
    strcpy(out_filename,output_str_full);
    
    av_register_all();
    //Network
    avformat_network_init();
    //Input
    if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0) {
        printf( "Could not open input file.");
        goto end;
    }
    if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) {
        printf( "Failed to retrieve input stream information");
        goto end;
    }
    
    for(i=0; inb_streams; i++)
        if(ifmt_ctx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO){
            videoindex=i;
            break;
        }
    
    av_dump_format(ifmt_ctx, 0, in_filename, 0);
    
    //Output
    
    avformat_alloc_output_context2(&ofmt_ctx, NULL, "flv", out_filename); //RTMP
    //avformat_alloc_output_context2(&ofmt_ctx, NULL, "mpegts", out_filename);//UDP
    
    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++) {
        
        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;
        }
        
        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);
    //Open output URL
    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;
        }
    }
    
    ret = avformat_write_header(ofmt_ctx, NULL);
    if (ret < 0) {
        printf( "Error occurred when opening output URL\n");
        goto end;
    }
    
    start_time=av_gettime();
    while (1) {
        AVStream *in_stream, *out_stream;
        //Get an AVPacket
        ret = av_read_frame(ifmt_ctx, &pkt);
        if (ret < 0)
            break;
        //FIX：No PTS (Example: Raw H.264)
        //Simple Write PTS
        if(pkt.pts==AV_NOPTS_VALUE){
            //Write PTS
            AVRational time_base1=ifmt_ctx->streams[videoindex]->time_base;
            //Duration between 2 frames (us)
            int64_t calc_duration=(double)AV_TIME_BASE/av_q2d(ifmt_ctx->streams[videoindex]->r_frame_rate);
            //Parameters
            pkt.pts=(double)(frame_index*calc_duration)/(double)(av_q2d(time_base1)*AV_TIME_BASE);
            pkt.dts=pkt.pts;
            pkt.duration=(double)calc_duration/(double)(av_q2d(time_base1)*AV_TIME_BASE);
        }
        //Important:Delay
        if(pkt.stream_index==videoindex){
            AVRational time_base=ifmt_ctx->streams[videoindex]->time_base;
            AVRational time_base_q={1,AV_TIME_BASE};
            int64_t pts_time = av_rescale_q(pkt.dts, time_base, time_base_q);
            int64_t now_time = av_gettime() - start_time;
            if (pts_time > now_time)
                av_usleep(pts_time - now_time);
            
        }
        
        in_stream  = ifmt_ctx->streams[pkt.stream_index];
        out_stream = ofmt_ctx->streams[pkt.stream_index];
        /* copy packet */
        //Convert PTS/DTS
        pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, (AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));
        pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, (AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX));
        pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
        pkt.pos = -1;
        //Print to Screen
        if(pkt.stream_index==videoindex){
            printf("Send %8d video frames to output URL\n",frame_index);
            frame_index++;
        }
        //ret = av_write_frame(ofmt_ctx, &pkt);
        ret = av_interleaved_write_frame(ofmt_ctx, &pkt);
        
        if (ret < 0) {
            printf( "Error muxing packet\n");
            break;
        }
        
        av_packet_unref(&pkt);
        
    }
    //写文件尾（Write file trailer）
    av_write_trailer(ofmt_ctx);
end:
    avformat_close_input(&ifmt_ctx);
    /* close output */
    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 occurred.\n");
        return;
    }
    return;
}

运行app的时候用VLC播放器打开我们的推流地址即可看到推流效果。

allluckly.cn

LBffmpegDemo下载地址