hls: make hlsEncryption optional even with Low-latency variant (#1530)

README.md

@@ -104,6 +104,7 @@ In the next months, the repository name and the docker image name will be change
   * [Browser support](#browser-support)
   * [Embedding](#embedding)
   * [Low-Latency variant](#low-latency-variant)
+  * [Low-Latency variant on Apple devices](#low-latency-variant-on-apple-devices)
   * [Decrease latency](#decrease-latency-1)
 * [WebRTC protocol](#webrtc-protocol)
   * [General usage](#general-usage-3)
@@ -1013,20 +1014,10 @@ For more advanced options, you can create and serve a custom web page by startin
 
 Low-Latency HLS is a [recently standardized](https://datatracker.ietf.org/doc/html/draft-pantos-hls-rfc8216bis) variant of the protocol that allows to greatly reduce playback latency. It works by splitting segments into parts, that are served before the segment is complete.
 
-LL-HLS is disabled by default. To enable it, a TLS certificate is needed and can be generated with OpenSSL:
-
-```
-openssl genrsa -out server.key 2048
-openssl req -new -x509 -sha256 -key server.key -out server.crt -days 3650
-```
-
-Set the `hlsVariant`, `hlsEncryption`, `hlsServerKey` and `hlsServerCert` parameters in the configuration file:
+LL-HLS is disabled by default. To enable it, set the `hlsVariant` parameter in the configuration file:
 
 ```yml
 hlsVariant: lowLatency
-hlsEncryption: yes
-hlsServerKey: server.key
-hlsServerCert: server.crt
 ```
 
 Every stream published to the server can be read with LL-HLS by visiting:
@@ -1041,6 +1032,24 @@ If the stream is not shown correctly, try tuning the `hlsPartDuration` parameter
 hlsPartDuration: 500ms
 ```
 
+### Low-Latency variant and Apple devices
+
+In order to correctly display Low-Latency HLS streams in Safari running on Apple devices (iOS or macOS), a TLS certificate is needed and can be generated with OpenSSL:
+
+```
+openssl genrsa -out server.key 2048
+openssl req -new -x509 -sha256 -key server.key -out server.crt -days 3650
+```
+
+Set the `hlsVariant`, `hlsEncryption`, `hlsServerKey` and `hlsServerCert` parameters in the configuration file:
+
+```yml
+hlsVariant: lowLatency
+hlsEncryption: yes
+hlsServerKey: server.key
+hlsServerCert: server.crt
+```
+
 ### Decrease latency
 
 in HLS, latency is introduced since a client must wait for the server to generate segments before downloading them. This latency amounts to 1-15secs depending on the duration of each segment, and to 500ms-3s if the Low-Latency variant is enabled.

internal/conf/conf.go

@@ -389,10 +389,6 @@ func (conf *Conf) CheckAndFillMissing() error {
 			return fmt.Errorf("Low-Latency HLS requires at least 7 segments")
 		}
 
-		if !conf.HLSEncryption {
-			return fmt.Errorf("Low-Latency HLS requires encryption")
-		}
-
 	default:
 		if conf.HLSSegmentCount < 3 {
 			return fmt.Errorf("The minimum number of HLS segments is 3")