HTTP Live Streaming (HLS) is here to stay, it works everywhere, high quality and stability, but latency or delays between the stream and the end user can be 60-90 seconds, if you streaming live events that can be a very big issue, imagine Sports betting? But with Wowza Streaming Engine it is possible to reduce the latency to 3 to 5 seconds. It is not good enough but for now there is no other solution.
Below we have some adjustments that using the Wowza Streaming Engine Manage, we can easily improve, although of course there are some negative components.
This risks inherent of the configuration adjustements are due to smaller chunk sizes may result in playback errors if you fail to increase the number of seconds built into the playlist. If a stream is interrupted, and the player requests the next playlist, the stream may be interrupted when the playlist doesn’t arrive.
Additionally, by increasing the number of segments that are needed to create and deliver low-latency streams, you also increase the server cache requirements. To alleviate this concern, ensure that your server has a large enough cache, or built-in elasticity. You will also need to account for greater CPU and GPU utilization resulting from the increased number of keyframes. This requires careful planning for load balancing, with the understanding that increased computing and caching overhead incurs a higher cost of operation.
Lastly, as chunk sizes are smaller, the overall quality of the video playback can be impacted. This may result into either not being able to deliver full 4K video to the player, or small playback glitches with an increased risk of packet loss. Essentially, as you increase the number of bits (markers on the chunks), you require more processing power to provide smooth playback; without it, you get packet loss and interruptions.
On the details page Properties tab, click Cupertino Streaming Packetizer in the Quick Links bar.
In the Cupertino Streaming Packetizer area, click Edit, and change the values for the following properties:
1- cupertinoChunkDurationTarget- Set the duration of each chunk in milliseconds. The default value is 10000, but the chunkDurationTarget must be smaller to reduce the latency of Apple HLS streams. For a one-second chunk size, set the value to 1000.
2- cupertinoMaxChunkCount- Sets the maximum number of chunks Wowza Streaming Engine stores in the available chunk list. The default value is 10, but for reduced latency streaming we recommend storing 50 seconds worth of chunks. For one-second chunks, set the cupertinoMaxChunkCount to 50; if you’re using half-second chunks, the value should be doubled (100).
3- cupertinoPlaylistChunkCount- Sets the number of items returned to the player in the playlist. The default value is 3, but for reduced latency streaming we recommend returning 12 seconds of data to the player. This prevents the loss of chunks between chunklist requests. For one-second chunks, set the cupertinoPlaylistChunkCount to 12; if you’re using half-second chunks, the value should be doubled (24).
B- On the Properties tab, click Customin the Quick Links bar.
In the Custom area, click Edit.
Click Add Custom Property, specify the following custom property settings in the Add Custom Property dialog box, and then click Add:
1- In Path, select /Root/Application/LiveStreamPacketizer.
2- In Name, enter cupertinoMinPlaylistChunkCount.
3- In Type, select Integer.
4- In Value, specify the minimum number of chunks required before Wowza Streaming Engine provides a playlist to the player. The default value is 1, but for reduced latency streaming we recommend requiring a minimum of 6 seconds worth of chunks. For one-second chunks, set the cupertinoMinPlaylistChunkCount to 6; if you’re using half-second chunks, the value should be doubled (12).
Click Save and restart the application to apply the changes.
Real-Time Messaging Protocol or RTMP was developed originally by Macromedia, which then became Adobe. It was a system to implement streaming of video, text and audio over the internet between a flash player and a server with the RTMP setup.
Using fragments between the server and the user, it maintains a stable connection and because of that it has low latency, meaning that there is a very short delay, between the server and the user. The delay is perhaps 1 or 2 seconds.
The RTMP servers available are Adobe Media Server, Red5, Wowza Streaming Engine, Nginx RTMP server and a few more, but this 4 are the most common, although Adobe is very expensive and Red5 is difficult, personally I prefer Wowza RTMP, which has a number of advantages, we will talk about this on another post.
Going back to RTMP, it is a TCP-based protocol which maintains persistent stable connections and allows low-latency communication. To deliver streams smoothly and transmit as much information as possible, it splits streams into fragments, and their size is negotiated dynamically between the client and server.
RTMP servers are ideal for live streaming but also for Ondemand video streaming, it is also a necessary component for live video chats.
RTMP Server, how it works
The server must be setup with a media server, like Adobe or Red5, then the video stream connects to the RTMP installed on the server, the video stream could be a laptop with a software installed, this software is an encoder, there are a number of them, OBS Studio, but the most common is the Adobe, FMLE, which you can download free at http://hosting-marketers.com/flashmedialiveencoder_3.2_wwe_signed.msi (for windows computers, Mac computers you can download directly at Adobe site.)
On the encoder you enter the server RTMP, which would be something like this:
Then you connect and start the broadcast. this stream will go directly the RTMP server and you can now setup a player for your users, if you using a RTMP player you will need to use a flash player, but using Wowza Streaming Engine on the RTMP server it converts the stream to a HLS protocol which can be used on many other platforms as well, like smartphones and HTML5 Players. Although the HLS has the latency issue because of the flash players end of live it is nearly impossible not to use it. Nowadays, with a good configuration you can reduce the latency to 3 or 4 seconds.
So we have, YOU on your laptop with a camera and an encoder >>> your internet connection and the RTMP Server connection >>> and finally the player on your site broadcasting your live event. Or your video files.
Well there are 2 red5’s, the open source red5 which is the one we use on our servers and red5pro, which is very expensive but still does not do what Wowza Streaming Engine does.
Red5 the open source can be used for ondemand streaming which is video streaming, you upload videos (in flv or mp4 format) to a red5 server and you stream the videos using red5, it is a better experience then using just a normal server, it starts faster because you don’t have to download the all file to the viewer computer and it is difficult for users to steal the video. But and this always applies, you can stream only to flash players, and most platforms are leaving flash, specially mobiles, so what I am saying is that red5 does not work well with smartphones, be Apple or Android devices.
You can also use red5 to stream live events, or video chats software’s.
Red5 ist ein Medienserver ähnlich wie der Flash Media Server von Adobe oder Wowza’s Media Server. Medienserver werden für Live-Übertragungen, Videochats, Live-Konferenzen und Videostreaming benutzt. Letzteres wird auch als On-Demand-Streaming bezeichnet.
Dies sind die Hauptvorteile eines Stream-Medienservers:
Vorteile für den Endkunden (Client):
Der Server findet automatisch die Verbindungsgeschwindigkeit des Client heraus und bietet auf dieser Grundlage den besten Videostream.
Die Wiedergabe startet schneller und der Benutzer kann zu jedem Punkt des Videos springen ohne darauf warten zu müssen, dass es komplett heruntergeladen wurde.
Vorteile für den Anbieter (Webmaster):
Die Möglichkeit zur Übertragung von Live-Streams von Veranstaltungen.
Die Möglichkeit erweiterte, interaktive Inhalte wie Livechats, Videokonferenzen, etc. anbieten zu können.
Die Video-Wiedergabe ist effizienter, benötigt weniger Serverressourcen und Datenvolumen.
Videodateien werden nicht auf dem Computer des Kunden gespeichert, daher ist die Wahrscheinlichkeit für Diebstahl von Inhalten geringer.
Detaillierte Statistiken, Diagnostiken, etc.
Hosting Marketers bietet seit 2008 Red5 und Wowza Hosting an. Wir haben langjährige Erfahrung und unser Kundensupport-Team ist bereit, Ihnen beim Einrichten Ihres Videochats oder einer Live-Übertragung einer Veranstaltung zu helfen.