nginx.conf example adaptive bitrate streaming

worker_processes auto;
events {
	worker_connections 768;	# Max clients = worker_processes * worker_connections. In this example: 1 * 768 = 768 max clients.
	# multi_accept on;	# "Off" will accept 1 new connection at a time. "On" will accept all new connections. Default is off.
	}

rtmp {
    server {
	listen 1935;		# This is the listening port. Open it on your router and/ or allow it in your firewall. These variables are possible:
				# (addr[:port]|port|unix:path) [bind] [ipv6only=on|off] [so_keepalive=on|off|keepidle:keepintvl:keepcnt|proxy_protocol].
        chunk_size 4096;	# Max chunk size for multiplexing. The bigger this value, the lower CPU overhead. Cannot be < 128. Default=4096.
	application live {	# Name it whatever you prefer. You will need at least one application, but you can have many more applications.
		live on;	# on|off. Enables this application and allowing live streaming to it. Default=on.

		## TRANSCODING USING FFMPEG EXEC ##
		## The following lines will take our incoming RTMP stream and transcode it to several different HLS streams with variable bitrates  ##
		## Once receive stream, transcode for adaptive streaming. This single ffmpeg command takes the input and transforms the source into ##
		## 4 or 5 different streams with different bitrate and quality. P.S. The scaling done here respects the aspect ratio of the input.  ##
		## EXEC - Many things are possible using exec. To learn more visit https://github.com/arut/nginx-rtmp-module/wiki/Directives#exec   ##

		exec ffmpeg -i rtmp://localhost/$app/$name -async 1 -vsync -1
		-c:v libx264 -c:a libvo_aacenc -b:v 256k -b:a 32k -vf "scale=480:trunc(ow/a/2)*2" -tune zerolatency -preset veryfast -crf 23 -f flv rtmp://localhost/hls/$name_low
		-c:v libx264 -c:a libvo_aacenc -b:v 768k -b:a 96k -vf "scale=720:trunc(ow/a/2)*2" -tune zerolatency -preset veryfast -crf 23 -f flv rtmp://localhost/hls/$name_mid
		-c:v libx264 -c:a libvo_aacenc -b:v 1024k -b:a 128k -vf "scale=960:trunc(ow/a/2)*2" -tune zerolatency -preset veryfast -crf 23 -f flv rtmp://localhost/hls/$name_high
		-c:v libx264 -c:a libvo_aacenc -b:v 1920k -b:a 128k -vf "scale=1280:trunc(ow/a/2)*2" -tune zerolatency -preset veryfast -crf 23 -f flv rtmp://localhost/hls/$name_                                    higher
		-c copy -f flv rtmp://localhost/hls/$name_src;
		}

	application hls {		# This application is for splitting the stream into HLS fragments
		live on;		# on|off. Enables this application and allowing live streaming to it. Default=on.
		hls on;			# on|off. Toggles HLS on or off for this application. Enables HTTP Live Streaming.
		hls_path /tmp/hls;	# Location to store the video fragment files. Will be created if it doesn't exist.

		## HLS_VARIANT - Used for variable bitrate streaming. Please read: https://github.com/arut/nginx-rtmp-module/wiki/Directives#hls_variant ##
		## When hls_variant suffix is matched on stream name then variant playlist is created for the current stream with all entries specified by hls_variant
		## directives in current application. Stripped name without suffix is used as variant stream name. The original stream is processed as usual.
		## Optional parameters following the suffix are appended to EXT-X-STREAM-INF in m3u8 playlist. See HLS spec 3.3.10. EXT-X-STREAM-INF for full list.

		hls_variant _low	BANDWIDTH=288000;	# Low bitrate, sub-SD resolution
		hls_variant _mid	BANDWIDTH=448000;	# Medium bitrate, SD resolution
		hls_variant _high	BANDWIDTH=1152000;	# Higher-than-SD resolution
		hls_variant _higher	BANDWIDTH=2048000;	# High bitrate, HD 720p resolution
		hls_variant _src	BANDWIDTH=4096000;	# Source bitrate, source resolution
		}
	}
}

http {
	sendfile off;				# on|off. Toggles the use of sendfile. Default=off. For optimal HLS delivery disable this.
	tcp_nodelay on;				# on|off. Forces a socket to send the data in its buffer, whatever the packet size. Default=on.
	tcp_nopush on;				# on|off. Sends the response header and beginning of a file in one packet. Default=off.
	server_tokens off;			# on|off|build. Toggles showing nginx version in the response header field. Default=on.
	default_type application/octet-stream;	# Emit this MIME type for all requests.

		server {
			listen 80;
			gzip off;

			server_name localhost;
			index index.html index.htm index.nginx-debian.html;

			location / {
				root /var/www/html/;
				add_header Strict-Transport-Security "max-age=63072000;";
				}

			location /hls {
			expires -1;
			autoindex on;

			types {
			application/vnd.apple.mpegurl m3u8;
			text/html html;
			}
			# root /tmp/;
			alias /tmp/hls;

			add_header Cache-Control no-cache;		# Prevent caching of HLS fragments
			add_header Access-Control-Allow-Origin *;	# Allow web player to access our playlist
		}
	}
}