How it’s possible that you can watch 4K live streams on the web without buffering.
Last updated: 25 April 2023
Watching high quality videos and streams on the web looks so easy these days. Do you remember the time that videos didn’t load, and streams were buffering all the time? Our industry has improved a lot over the years, with great innovations to bring you a video experience beyond broadcasting. One of the key elements in enabling high quality on the web is transcoding. We just released our new MaelStrom Live transcoding service, so let’s dive into the world of transcoding.
The benefit of transcoding
Transcoding is the process of generating multiple qualities and resolutions of a video or a stream. The primary benefit of having multiple qualities, is that video players can adapt the stream quality continuously to fluctuating bandwidth. Even when your WiFi or 5G connection drops or fluctuates, you can still experience a fluent stream at the highest possible quality given the circumstances, thanks to live and on-demand adaptive bit rate streaming. Transcoding is an important process in a professional streaming environment. It is strategic for any professional content supplier.
There’s also a downside to transcoding. It takes an already encoded signal and then recodes it. This will always cause some form of picture degradation. Encoding is not lossless. Re-encoding will introduce artefacts, especially when lower qualities or resolutions are created. We’re not there yet that AI’s can improve picture quality (at scale, within reasonable costs), but we will in the future. For now, we must rely on advanced codecs to squeeze the maximum out of the available computing power and energy. Fortunately, there are many ways to reduce picture degradation to the minimum.
Long live codecs
Video is by far the heaviest application on the web. It causes over 80% of the internet’s traffic. Codecs are the technology to compress and decompress video. Codecs are math, but they are also magic. If there was no compression, online video with decent picture quality would simply be impossible on the web. The internet would instantly crash under the extreme load. The widest used video codec today is H.264. (Back in 1993 when we started to upload our first videos to the web, we used MPEG1, it took an hour to upload a 1 minute video, the horror 😉
More efficient codecs are being adopted too, such as H.265 (HEVC) and AV1. These codecs have more advanced algorithms to further compress video, while maintaining picture quality. The larger the picture (beyond full HD), the better their performance. Because of the extreme compute power (and energy) that’s needed to compress and decompress with these codecs, they are hardly used for Full HD and lower qualities. More and more devices have hardware acceleration for decoding, and we believe that these new codecs will take over the realms of QHD, 4K and beyond.
Quality starts with the source
You probably heard about CICO before: crap in, crap out. If the origin picture quality is bad, don’t expect a decent transcoding output. It will be worse. The better the lighting, the cameras, the studio equipment and the original encoding feed, the better transcoders can do their job. Create a high quality reliable live picture stream, with deinterlacing, with constant bit rate or mild variable bit rate encoding, a steady framerate with reliable keyframe settings. Transcoders can fix bad encoding signals, but bad encoding settings can also get worse in transcoding and transmuxing.
Video transcoding is computing resource intensive, and therefore also very energy consuming. There is a balance between optimal picture quality and resources (or costs) to throw at: CPU’s and energy. With live streaming there’s another factor: real-time transcoding. The time to do all kinds of smart optimizations is limited.
Transcoding saves costs down the line
Transcoding does cost some money one-time, but these costs are relatively small compared to long-time and scaling costs like storage and traffic. Having a good transcoding strategy saves you money in the long term. A good transcoding strategy also keeps your viewers happy: there’s tremendous value in there too.
A balance between quality and costs
Finding a good balance between costs and quality is hard, and the balance depends on the use case too: are you selling premium blockbusters, or are you offering quick news videos? With the first case, quality is top priority, with the latter the focus is on costs. A decent transcoding service therefore needs to offer the flexibility to control the balance between quality and costs.
MaelStrom Live: focus on quality, and costs
One of our company key values is quality. We therefore don’t have a business model that sells viewing per minute, since this would give us a financial incentive to drive down bit rates and video quality. Another important value is TCO: total cost of ownership. You should have full control over quality and costs.
To offer you full control over both quality and costs, our platform is open. You can use transcoding (like all other services) in three levels: easy, smart, expert. Easy means that we automatically do transcoding for you, with an optimal quality-price balance. Smart means that you can enable and disable qualities per title, and per stream, in a user-friendly interface. You can create automated workflows, don’t need expensive experts, and still have full control over quality and costs. Expert means that you can do your own transcoding and bypass Jet-Stream’s services. There are always edge cases where you could need this. You can mix easy, smart, and expert implementations, to support multiple workflows and use cases.
Hybrid hardware and software
To create a better balance between quality and costs, MaelStrom Live is a unique hybrid software and hardware solution. It combines the flexibility and tuning of software, with the efficiency of hardware accelerated decoding and encoding: high picture quality and low costs can go hand in hand. Opposed to CPU or GPU encoding, hardware accelerated encoding reduces the energy footprint by a whopping 89%, while offering a picture quality beyond broadcast grade, which is a challenge with GPU based accelerators. An extra benefit is that hardware transcoding adds a latency as low as 1 frame, while CPU based encoding adds multiple seconds of delay.
Jet-Stream runs its own cloud infrastructure, so we can easily create and integrate such accelerated infrastructures, while other video transcoding vendors and video platforms must depend on third party generic, CPU based, virtualized clouds, with their performance and cost drawbacks.
Videos and livestream are not static images. One video can be a talking head or a static presentation, while another one can be full of glitter, laser shows, pans, tilts, zooms, motions, and fast scene cuts. Both types of scenes can be in one video or stream. Instead of encoding at a fixed bit rate, MaelStrom’s optimized encoders instantly analyse the details in videos and live streams. When needed they decide to throw more resources to a scene, and reduce resources when possible. To guarantee a good picture quality, there is a bottom threshold, and to prevent unnecessary peaks, there is a bandwidth cap. Overall, scene optimization guarantees a very high picture quality while saving bandwidth and costs.
By having live transcoding integrated in one cloud infrastructure, there’s no lag between different networks. Jet-Stream Cloud is optimized for streaming. For example, there’s no virtualization, storage is designed to serve 8K video, and network packet sizes are increased to reduce TCP overhead. As a result, Jet-Stream Cloud sends out adaptive video segments 430% faster than generic clouds and CDNs can do. The serving time of Jet-Stream Cloud is always fast and steady, not as fluctuating as we have seen with those generic services. Streams start faster and there is another advantage: the adaptive bit rate switching algorithms in video players measure how fast segments are getting in. The faster, the higher the chance that the algorithm selects a higher bit rate in the ladder, giving the user access to a steadier and higher picture quality compared to generic video platforms, CDNs and clouds.
Jet-Stream Cloud is not just a video platform. We’re also into audio. We process, and host radio channels, podcasts, and music too. If you ask viewers what they hate least and most, then they all tend to accept incidental video bit rate switching. It beats (re)buffering. What is hated most are audio degradation and audio drops. Therefore, MaelStrom Live passes through your audio channels, unaltered. If you send high fidelity, lossless audio, everyone will hear this in its original pristine quality. This means that you can freely stream surround audio, multilingual audio channels and even Dolby Atmos. We take care of the audio and video syncing.
HDR and FPS adoption
MaelStrom Live respects your framerates and HDR picture quality. If you stream at 25fps, MaelStrom transcodes at 25fps. If you stream at 60fps, MaelStrom transcodes at 60fps. And if you encode a video source with HDR, all bit rates will be encoded to HDR. All MaelStrom does is scale and encode with high picture quality tuning.
There are cases where you may need to stream the original encoded signal unaltered to your users. For example, when you stream live surgeries in 4K, you need to guarantee pixel by pixel that the exact same image is streamed to every user. We don’t want students to learn to cut the wrong artery due to transcoding artefacts, now do we? Jet-Stream Cloud lets you upstream your own single or multi bit rate streams and sends them unaltered in their original pristine quality to the viewers, bypassing the MaelStrom Live transcoding service. This way you can stream even beyond 8K resolutions, apply your own DRM, or do smart live content personalisation.
We hope this blog gave you some insights in the world of transcoding and why it is so important. We also hope that you learned how Jet-Stream’s new MaelStrom Live service gives you full control over your transcoding strategy and offers the best quality – cost control. Feel free to reach out for a demo or a trial account!