Whether it's sports, news, live music, chat, or real-time event coverage, everyone wants it. The RealSprint team has developed a brand new solution for live video streaming to mobile browsers. It is unique, it is global, and you have never seen anything like it!
Our latest innovation for the live streaming space is called DALS. Dynamic Adaptive Live Streaming. It is a technology for ultra low latency, designed for web sites/application where low latency is essential:
Our technology has been in production in Europe since July 2016, and has been very stable and reliable.
Sound interesting? Please take a look at the video below. It is a real world setup, using phones over 3g,4g and Wi-Fi. (do you want to say iPhone/Android smartphones?)
There is always a tradeoff between latency, stability and quality/bitrate. Production setups in Europe typically renders
a very stable stream at 1.3-1.8 seconds latency running 720p at 2 Mbit/s consumed over 3g or 4g mobile networks.
Trans-Atlantic streams, from Europe to West Coast US, adds another 250 ms of latency depending of the physical distance and network throughput.
Our solution allows dynamic buffering which means that the buffer size can be defined as a window between “ideal” and “maximum”. For example, 0.5 sec to 1.5 sec. Depending on the client connectivity, our technology will adapt to a suitable buffer size for each connection. The setup can also be configured to keep all viewers at the same latency, keeping the latency differences between viewers to a minimum.
Depending on the use case, DALS can be configured for significantly reduced latency, down to around 240ms, or the opposite in order to be more resilient to severe network congestions but with a higher latency. The definition of Quality of Experience (QOE) differs between use cases, but for low latency applications low number of buffering events and low latency are typically key. Knowing that the viewers are experiencing the SAME latency could be equally as important as the latency itself. Experiencing content in sync with other viewers allows for social interaction which may be as important as the content itself: Low latency is key, social is the killer app!
DALS has been optimized from the ground up to deliver low latency for live streams - on mobile and desktop running a normal browser. HLS and DASH were primarily designed for video on demand, but “works” for live streams as well. HLS and DASH do have many important features, but both lack core support for low latency live streaming. There are several reasons for this including too large segment sizes, inefficient HTTP communication and the lack of two-way communication between the client and the server. A typical HLS/DASH video player simply doesn't know what “live” is, and has no reference clock/timer that can be used to maintain low latency, or even the keep same latency over time. Even if a HLS/DASH stream initially could have a latency around 10-20 seconds, it may actually increase over time depending on client buffering events. We have heard customers experiencing HLS-latency of 90-180 seconds… not really live, and very far away from what DALS can provide. We promise!
Another problem with HLS/DASH is that they don't work in the market leading browsers. In many cases, both HLS and DASH need to be deployed in order to cater to all target devices.
So, what about real-world latency on HLS/DASH vs DALS? If we leave out the lab-style setups and instead focus on real-world applications that must work on regular Wi-Fi, 3g or 4g connections, we find the core advantages of DALS:
Real-world latency for HLS and DASH depends on several factors, and depending on the setup and CDNtechnology/ performance, it may vary considerably. DALS won´t. It will keep the viewers within a latency very close to the preset amount, and the latency will be the same over the entire viewing session.
One more important thing to highlight is that DALS, as a single format/protocol, works on *all* major mobile phones, in a browser, as well as on desktop where all major browsers are supported.
DALS technology works in a browser and does not need an app in order to provide ultra low latency. This applies to iOS Safari, Android Chrome and desktop (all major browsers).
In addition to the use cases mentioned above, there are many others. Low latency is key to many applications - especially where user interaction is needed.
RealSprint designs and implements custom solutions for low latency live streaming. We do this by using our core technology DALS (Dynamic Adaptive Live Streaming) (pat pend). RealSprint’s primary focus is on high end setups where low latency is business critical and every millisecond counts; where interaction is key and viewers need to watch the stream in sync. All this without installing an app.
Our technology does not replace the typical VOD setup - instead it is a compliment designed for low latency streaming (near real time). DALS can be used as a compliment to media servers such as Wowza or Adobe FMS, or traditional CDN streaming services, and accept regular RTMP streams or raw HD-SDI as ingest.
DALS is a platform independent solution for streaming to mobile/desktop, and can be integrated into different workflows, applications, payment systems and infrastructures.
In addition to our core technology we provide professional services such as system design, development & integration.
Please note that we do not provide our technology & solution as a piece of downloadable software or SAAS (yet), nor do we offer CDN services. We deliver customized setups for our customers. RealSprint is independent of all network providers and existing CDNs, but our technology is compatible with all major VM providers such as Amazon AWS and Digital Ocean and can scaled to a large global audience using multiple POPs & Clusters.
Our solution has been serving customers in Europe since mid 2016. Our technology can be run on VMs, physical machines, private clouds or generic cloud providers. Based on your need and use case, we help you design a suitable setup and integration with your backend servers, websites and mobile apps.
Our technology is based on dedicated encoders/transcoders, high performance edge servers and load balancers, and a custom JS player. All parts of DALS are custom built and highly optimized for low latency and high throughput.
As an example, the edge servers of DALS serves around 20Gb/s of outbound streams using four (4) cores of a baseline HP server. Throughput on the edge servers are typically limited by the network interface card and not the CPUs.
The JS Player is also optimized, using the latest WebAssembly technology in order to reduce battery consumption, and maximize QOE.
For ingest, DALS typically uses a normal RTMP stream, or a native HD-SDI video source feeding the native encoder of DALS. RTMP ingest is supported but may introduce a slightly higher latency depending on codec configuration, and the performance of the products used to create the origin RTMP stream.
All DALS components have been developed using efficient state of the art tools and technologies. All components may be customized and optimized for different use cases. Being compatible with container systems, such as Docker, our software is easy to install, upgrade, maintain and scale.
Scaling to multiple POPs can be done in several ways depending on the use case.
In order to stream live content to mobile devices, while providing low latency and a stable stream even on non-stable 3g networks, all components in the architecture must be optimized and designed with mobile in mind. This means that the encoder, the transport protocol, the edge servers, the infrastructure and the streaming clients must be carefully designed to utilize the most optimal technologies and features available on mobile devices. In order to accomplish this, we had to think outside the box. (The typical protocols and off-the-shelf products and solutions simply did not quite fit into the equation.) Hence, our new streaming solution has been custom built from the ground up. ...And yes, it works like a charm. :)
Our technology (DALS) delivers low latency streaming to mobile and desktop. It has several advantages over HLS and DASH. Low latency is just one of them.
The differences between DALS and HLS/DASH are very noticeable when trying to maintain a low latency stream over a less reliable network such as a 3g or 4g mobile connection. HLS or DASH, even when using 2-4 seconds of segment sizes, will introduce substantial latency and it will also be difficult to control over time. It´s not uncommon that latency actually increases over time because of the buffering events caused by network drops or congestions. This means that the latency may be very different for each individual viewer. DALS solves this, prohibiting latency differences; latency cannot increase over time.
We provide solutions based on our technology, either directly or via integration partners. Our technology is not yet available for licensing or SAAS (only).
Please contact us for more information.
Developing ground breaking solutions for video streaming and live video has been a RealSprint focus since its launch in 2013. Our backgrounds in television, live events, media and broadcasting, in combination with our expertise in software development, have been vital for our growth and success. Adding young and very talented developers to the mix, with senior architects, business developers and managers, has been a great way for us to move “fast-forward” with the latest technologies.
Since 2013 we have been working almost exclusively with live streaming for online service-and content providers. In close cooperation with our clients, we drive innovation and bring exciting and important new products to the marketplace. This ranges from creating POC’s, to delivering full-stack solutions, ready for production. We employ a broad portfolio of products, standards, platforms and SDKs; including Wowza Streaming Cloud, Adobe Media Server, several different CDNs and virtually all important development platforms related to video, streaming and real-time video processing. To achieve high performance and scalable solutions, we combine the best of C++, C#, C, Node, CUDA and even Erlang – whatever it takes. We chase microseconds on the web and clock cycles on our servers. In order create a cost efficient and scalable solution, there are no easy shortcuts.
Live Streaming to mobile browsers has been a significant challenge. Until DALS, there has not been a silver bullet solution or product working on both mobile (iOS and Android browsers), as well on desktop. For streaming from/to an app there are many options for low latency streaming, but not all customers want an app. In some cases, an app simply isn’t an option because of the nature of the application, the business case or just pure and simple economic reasons. Some customers prefer a solution that works directly in the browser – without the need to install an app or a plugin. Content delivered through our technology is instantly shareable, and viewable - in one single click. By the way… who wants an app for every single web page they like or view? It is just too much.
This is where our latest developments shine and excel. Together with one of our most important customers and partner, NetEnt (publ.), our R&D team has developed a patent pending application which has cracked the code for low latency streaming to mobile: sub second latency; HTML5-based high quality HD streaming; in-line video, 100% compatible with Safari on iOS, Chrome on Android and all major browsers for desktop.