Mobile and laptop devices may overheat under prolong use

VDO.Ninja offers a lot of power and unconstrained video quality. Some devices however will overheat if pushed for prolonged periods though, as they were not designed necessary for professional streaming video applications in mind. Still, there are steps you can take to minimize the heat generated by devices with software settings and configurations.

Lowering the quality

The viewer has control over the requested quality. 1080p video on a mobile device uses up a lot of power, including by data-transmission and the video encoding itself. Try using a lowering resolution, either by adding &quality=2 to the publisher's link or by adding &scale=50 to the viewer link.

The same goes for video bitrates; the default is around 2500-kbps, but perhaps try 1500-kbps instead. For example, https://vdo.ninja/?view=MYSTREAM&codec=h264&scale=50&bitrate=1500

Hardware encoders on mobile devices

Some mobile devices have support for hardware-based H264 video encoding. An iOS device has three 720p30 hardware encoders, for example, while Android devices are hit and miss.

To reduce heat for mobile devices, try using &codec=h264 on the viewer side to request the video has h264 format. If the mobile publishing device supports it, it will use the hardware encoder for publishing. This will increase the chance for corrupted video, such as all-green flashes of video, but it should greatly reduce heat and power consumption.

Normally H264 will be used automatically if the hardware-device has a hardware-decoder, but this might not always be the case. Just double check, as VP8, VP9, and AV1 are rarely hardware-encoded. Keep in mind iOS devices are limited to 720p30 when using H264 hardware encoding, but can do 1080p30 with VP8 in software; life is full of trade-offs it seems.

When it comes to hardware encoding on laptops, H264 encoders sometimes kick-in, but the vast majority of the the time the browser will choose to still encode H264 video using a software-encoder. For the best chance of it working, use a Chromium-browser, like Chrome.

It should be noted that hardware encoders are finite in availability -- this means that they are often not something you can rely on when in a group-video call with multiple peers requesting video streams. If using an Nvidia GPU, you might be limited to 2 or 3 hardware encoders, just like an iOS device, which doesn't work well if streaming to many viewers. The VP9 codec offers higher quality than most default codecs, but it also uses higher CPU load. AV1 may be even worse, so sometimes H264 is best. Just something to be aware of. Currently a web-browser does not allow a single video encoder to share video with multiple guests, at least not at low-latency. This is a limitation that will be addressed in the future, but it's a current limitation now.

Meshcast.io and server-based restreaming

VDO.Ninja is peer-to-peer-based, which works great for linking one camera to one viewer. The more viewers though, as mentioned, the more load is created on that guest. Just the act of uploading data uses power, so mobile devices are also quite poor at restreaming to multiple viewers even if encoding video wasn't already an issue. This is why the video quality on mobile devices between guests is set very low by default.

Meshcast.io is by the same creator as VDO.Ninja, but it's a server-based solution to sharing low-latency video. It has a lower-maximum video quality, it isn't peer-to-peer-based, and it has numerous other short comings, but it does allow a mobile device to encode just one video stream, upload just one video stream, and still share that video with numerous viewers. Feel free to experiment with it, it's free, and if more quality and reliability is needed, there are paid options that are similar to it available. The cost of restreaming with a server-solution is about 15-cents per GB, depending on quality of the service. This is why Meshcast.io needs to limit it's video quality to afford a free-offering; server solutions are expensive!

Group rooms, multiple-scenes, or multiple viewers

Every viewer of a stream adds to the heat and load experienced by the publisher of that stream. To reduce heat as much as possible, only allow one viewer of a stream to be active. Group-scenes, multiple-guests in a room, and multiple view-links each consistent as an active viewer. There are ways to optimize in these situations, but they may not be obvious. (&optimize=0, for example).

In the case of an iOS device, since it only has 3 hardware encoders, the device will switch to VP8-software mode or just stop working all together if those get exhausted. iOS devices are rather poor at software-encoding video, especially at higher resolutions, so be careful.

You can force-limit the number of connections and viewers with the &maxconnections=1 parameter, added to the publisher's URL. If you are accidentally viewing the video stream multiple times, this will help prevent more than one viewer from having access.

Start with a full-battery

Charging a mobile phone creates heat. If you start charging your device after you've already started streaming, that will increase the heat. Try starting with the phone already at a 100% full-charge to avoid even more unnecessary heat.

Smartphone add-on heatsink and fan

Professional cameras do often include a small fan inside them to reduce heat. Consider buying a heatsink that can be mounted onto the back of your smartphone, with an optional fan to turn on if it starts getting hot. These are not super common, probably not super effective, but they can be had for not much money.

Sometimes a thick protective case can insulate a smartphone, making it hotter than needed, too.

I've done a YouTube video demoing how cooling your smartphone can reduce heat and also improve performance, as a hot phone my throttle the performance. See below:

Web apps are intentionally limited on mobile devices

It is not possible to change between apps, screen-share, or turn off the display when using a web-app, like VDO.Ninja. You can turn down the screen brightness manually on your phone though, which will be nearly as effective.

Also, If you use ?push=STREAMIDGOESHERE&cleanoutput&nopreview&chroma=000&view as a publishing link, you can hide pretty much everything on the screen, and if using an OLED display, this should reduce power usage. This is a great option if you wanted to set your phone up as a dedicated webcam and were worried about the screen generating heat.

Native mobile app of VDO.Ninja

There are native Android and iOS app versions of VDO.Ninja, but they are very limited at the moment. They can be used to turn a phone into a dedicated webcam, and that's about the only they are good at. The Android app supports screen-sharing, which is the main advantage of using it.

Until the native apps are further developed, they are not great options for most users. They may still however use less CPU and may generate less heat though, just due to how basic they are in function.

Download the mobile app versions here: https://docs.vdo.ninja/getting-started/native-mobile-app-versions

Please contact steve at steve@seguin.email or via discord (discord.vdo.ninja) if you'd like to contribute to development of these native versions. The cost, time, and skill requirements for their continued development are quite steep.

Laptops and Macbooks

Older 2011-era Apple notebooks are prone to overheating. Even newer generation Macbooks can overheat if stressed. Normally these systems throttle the CPU to be MUCH slower when they get too hot, so it may appear like there is a network issue.

Ensure you are not running a laptop at 100% CPU load, make sure it has plenty of cool ventilation, ensure the fans are clean and not full of dust, start with a full battery and keep the computer plugged in

Raspberry Pi, Nvidia Jetson, and dedicated hardware-encoders

VDO.Ninja has limited support for hardware encoders. Hardware encoders greatly reduce heat, but they are often poorly suited for low-latency video that requires tolerant packet-loss capabilities and dynamic resolutions. Green/purple/grey coloring of video, lost frames, and distorted video blocks are common when using hardware-encoders at very-low latencies.

There is support for the Raspberry Pi, both software-encoder and hardware-encoder options, but the hardware-encoded option is the most limited and challenging. The current project supporting this offering is here: https://github.com/steveseguin/raspberry_ninja

Like with the native mobile app versions, the capabilities of this option is very limited. It does not support group-rooms and it does not yet support multiple viewers. Since many are using the Raspberry Pi wirelessly, it must also be said that it has very poor support of packet loss recovery -- the video will often not be smooth, especially if the WiFi signal is not very strong.

Using a Chromium browser with a Raspberry Pi, in software-encoded mode, will probably give more reliable results, but also generate a lot of heat and limit the maximum video resolution a lot.

Just as a consideration though, the Nvidia Jetson development boards support higher resolutions and seem to have better support for dynamic video and packet loss recovery. These products are a bit more expensive, but tend to work better than a Raspberry Pi when it comes to encoding HD video. I have a support for the Hardware-encoding capabilities of a Jetson here, buried away alongside the files for the Raspberry Pi: https://github.com/steveseguin/raspberry_ninja It's pretty basic support also currently, but has a lot of potential.

In the future, more professional video-centric hardware encoding options with built-in LTE/5G transmitters will support VDO.Ninja in a basic publish-only mode. This advancement will be due to the adoption of community standards for publishing low-latency video, although don't hold your breath for progress here.

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