srs rtmp server with hls multiple bitrates

hls.conf

listen              1935;
max_connections     20;
daemon              on;
pid                 /usr/local/srs/objs/srs.pid;
srs_log_tank        file; # console;
srs_log_file        /var/log/srs.log;
ff_log_dir          /dev/null;

# can be: verbose, info, trace, warn, error
srs_log_level       warn;

stats {
    network         0;
    disk            sda vda xvda xvdb;
}

vhost __defaultVhost__ {
    enabled             on;
    mix_correct         on;

    transcode live/stream {
        enabled     on;
        ffmpeg      /usr/local/bin/ffmpeg;
        engine input {
            enabled         on;
            iformat         live_flv;
            vfilter {
                v           quiet;
            }

            vcodec          libx264;
            vfps            25;
            vwidth          512;
            vheight         288;
            vprofile        main;
            vpreset         medium;

            vparams {
                crf         23;
                x264-params keyint=50:min-keyint=25:scenecut=-1;
                maxrate     650k;
                bufsize     1300k;
                refs        3;
                c:a         copy;
                f           flv;
                y           rtmp://stream-low/live/low;
                c:v         copy;
            }

            acodec          copy;
            oformat         flv;
            output          rtmp://stream-high/live/high;
        }
    }
}

vhost stream-high {
    enabled             on;

    hls {
        enabled         on;
        hls_path        /var/www/html;
        hls_fragment    6;
        hls_window      1800;
        hls_cleanup     on;
        hls_dispose     0;
        hls_m3u8_file   live/high.m3u8;
        hls_ts_file     live/high-[seq].ts;
    }
}

vhost stream-low {
    enabled             on;

    hls {
        enabled         on;
        hls_path        /var/www/html;
        hls_fragment    6;
        hls_window      1800;
        hls_cleanup     on;
        hls_dispose     0;
        hls_m3u8_file   live/low.m3u8;
        hls_ts_file     live/low-[seq].ts;
    }
}

hosts

# /etc/hosts
...
127.0.1.2       stream-high.local     stream-high
127.0.1.3       stream-low.local      stream-low
...

master.m3u8

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-ALLOW-CACHE:YES
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-TARGETDURATION:15
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=1300000,CODECS="mp4a.40.2,avc1.64001f",RESOLUTION=1024x576,NAME="1024"
live/high.m3u8
#EXT-X-STREAM-INF:PROGRAM-ID=1,BANDWIDTH=650000,CODECS="mp4a.40.5,avc1.420016",RESOLUTION=512x288,NAME="512"
live/low.m3u8