HLS fragment length and playlist length with nginx-rtmp module

Question

I installed nginx and the nginx-rtmp module on Amazon Linux. RTMP stream works fine, but some configure about HLS does not work.

On configuration file,

rtmp {    
    server {    
        listen 1935;    
        max_streams 32;    
        chunk_size 4096;    

        access_log /var/log/nginx/rtmp_access.log;    
         application live {    
            live on;    
            hls on;    
            hls_path /usr/local/nginx/html/hls;    
            hls_playlist_length 4s;    
            hls_fragment 1s;    
            hls_continuous on;    
        }    
    }    

but when I start streaming, .m3u8 file is created like this

#EXTM3U
#EXT-X-VERSION:3
#EXT-X-MEDIA-SEQUENCE:0
#EXT-X-TARGETDURATION:8
#EXT-X-DISCONTINUITY
#EXTINF:8.333,
test-0.ts
#EXTINF:8.333,
test-1.ts
#EXTINF:8.334,
test-2.ts

These .ts file length and playlist length are not expected. Why?

Solution

It seem likes your video source has a special keyframe, which is minimum at 8s, you can't cut it into 1s segments. And the hls_playlist_length must be longer than each segment'length. You should change hls_playlist_length to 20s for example.