September 30, 2020

Q3 2020 news: NDI in Nimble Streamer, RIST in Larix Broadcaster, SRT in TV Players

Softvelum team keeps improving the products bundle and we'd like to share the most significant updates with you.

Nimble Streamer

Our flagship product has a number of interesting updates.

Larix Broadcaster

Larix Broadcaster was described in a couple of tutorials:

As for new features, we have them as well.

  • RIST streaming protocol is now supported for Larix Broadcaster for both Android and iOS. It's built with libRIST version 3.0.0 and uses RIST Main profile. Watch video tutorial showing RIST streaming from mobile.
  • Larix Broadcaster now has streaming pause for both Android and iOS. Long tap on Start will pause the stream without disconnecting it, video track will contain a black screen, audio track will contain silence.

Last but not least. We've started to describe our approach to quality assurance of our mobile products in our github Larix testing repo. Here are the areas which we've covered already, more pages are coming soon, as well as new tests for RIST:

Larix Player

Larix Player is the new name of our playback solution for Android and iOS formerly known as "SLDP Player". It's capable of SRT playback as well as Icecast, SLDP and other protocols.

  • Larix Player free app is available in AppStore and Google Play while Larix Player SDK is available for premium licensing.
  • Larix Player is now available in Apple TV / tvOS which means SRT can be played on all Apple devices. Check our Apple developer page for all apps. Watch this video tutorial for setup.
  • Larix Player is also available on Android TV. This allows playing SRT on STBs and TVs, as well as creating your own playback apps with our SDK. Visit player page for details.

That's all for now.

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September 29, 2020

RIST support in Larix Broadcaster

RIST protocol support is now available in Larix Broadcaster for iOS and Android. It has RIST Main Profile Baseline Level. As of December 2020, Beta version of Larix uses libRIST version 0.2.0 rc2.

To use RIST in Larix connection, enter URL with rist:// prefix, like
If you need to control RIST behavior via custom parameters, just add them into URL, like


Full list of available parameters is available in libRIST headers here under "Rist URL parameter names for peer config" section.

This tutorial video shows the setup and usage example of RIST.

Check other features of Larix Broadcaster for your respective platform.

September 15, 2020

Building Quick Sync-only pipeline with Nimble Transcoder

Live Transcoder for Nimble Streamer provides many features for transforming live content using both software libraries and hardware acceleration.

Intel® Quick Sync is fully supported in Live Transcoder for decoding and encoding but all filtering operations were performed using CPU. That caused extra resources usage to transfer processed frames among CPU, GPU and RAM.

Nimble Live Transcoder now allows building transcoding pipelines which are performed completely with Quick Sync hardware acceleration. This is done using specific FFmpeg libraries which we use in addition to our own code.

This article shows how to set up this Quick Sync-powered processing chain.

1. Installation and initial setup

We assume you've already set up Nimble Streamer, it's been set up to get an incoming live stream and you've tested basic streaming. In our example we'll use a stream whose application name is "input" and stream name is "source".

If you're not familiar with Live Transcoder, take a look at Transcoder documentation reference.

Notice that the described functionality is available on Ubuntu 20.04 only. We'll support other upcoming LTS Ubuntu releases as well.

The basic steps to make Quick Sync working are as follows:
  1. Create a transcoder license and subscribe for it.
  2. Install Live Transcoder add-on.
  3. Create some simple scenario with CPU transcoding (e.g. downscale your stream to 240p). This way you'll make sure the transcoder was set up properly.
Now create a new scenario to start a new pipeline setup.

2. Decoder setup

Once you create a new scenario, drag and drop a blue decoder element onto the dashboard. There you need to specify "quicksync-ffmpeg" in Decoder field.

That's it. Now let's set up filtering.

3. Using filters

Once the frame is decoded you can process it via a set of ffmpeg filters which will work via Quick Sync. Nimble Transcoder supports a number of those, here are the most frequently used. Notice that you can refer to FFmpeg source code for more details about custom filters. As of September 2020, Nimble Transcoder uses FFmpeg 4.3.1 for some of its operations, including Quick Sync filters.

"Split" - allows creating several identical outputs from input video. It's available as a filter element in a tool box of Transcoder UI.

"Picture" - another filter available via UI element. Its setup for Quick Sync will look like this:

"fps" filter sets the frames per second rate and is defined via a custom filter. Its name is "fps" and the value is "fps=<number>", like "fps=30".

"scale_qsv" filter allows resizing the image. Add a custom filter into your scenario, set name to "scale_qsv" and then use filter parameters of your choice separated by comma. Common parameters are "w" (width) and "h" (height).

Other options include "format", "mode", "low_power", "hq". Please refer to FFmpeg sources file vf_scale_qsv.c for more details.

"vpp_qsv" filter allows transforming the content in a lot of ways, some of its parameters include "deinterlace", "denoise", "framerate" as well as flipping, scaling and a lot more. Please refer to FFmpeg source file vf_vpp_qsv.c for a full list of options.

4. Encoder setup

In order to encode video using Quick Sync within the hardware pipeline, you need to define Encoder as "FFmpeg" and set Codec to "h264_qsv" for H.264/AVC codec.

You can then define its custom parameters like "profile" for encoding profile , "b" for bitrate and many others which you can find in FFmpeg source file qsvenc_h264.c.

If you need to encode to H.265/HEVC, your Codec field must be set to "hevc_qsv".

It also supports a number of parameters like "b" for bitrate and you can find a full list in qsvenc_hevc.c from FFmpeg sources.

If your input stream is anamorphic you might need to save its SAR parameter in the output as well, especially if you’re using a 'scale' filter in your Transcoder pipeline while DAR = SAR x Width / Height. Nimble supports keeping input SAR using keep-sar parameter set to true for encoder in its ‘Video output’ section. SAR/DAR/PAR correlation is described in this article.

Once you finish your scenario and save it, you'll be able to transform your incoming video stream using only Quick Sync hardware acceleration.

When you have a video pipeline set up, you need to define the audio part. If you don't need any sound transformation, you can add a passthrough for it just like it's described in other setup examples.

If you have any questions, issues or questions, please feel free to contact us.

Related documentation

Live Transcoder for Nimble StreamerTranscoder documentation reference,

September 10, 2020

Make thumbnails for live streams

Nimble Streamer allows generating thumbnails on-the-fly for any outgoing stream. At the moment it supports two formats:

  •  a single-frame MP4 file which can be embedded into any web page via <video> tag.
  • a JPG file.

In order to start generating those thumbnail, you need to enable Generate MP4 thumbnails or Generate JPEG thumbnail parameter for either Global setting of the server or for specific applications' settings as shown below.

Nimble Streamer uses decoding and encoding libraries from Nimble Live Transcoder to get the image from the stream and then encode it into JPG.
So to get his feature working, first you need to install Live Transcoder and subscribe for a license. Once you've installed Live Transcoder and registered the purchased license, you can enable this feature.

Once the parameter is enabled, you can access the generated thumbnail via this kind of URL:


You may also use https:// if SSL is properly set up on your Nimble Streamer.

Here are the examples of global and per-application "Generate MP4 thumbnails" and "Generate JPEG thumbnails" setting enabled.  The thumbnails are re-newed within a Interval period which you set up after checking the checkbox, by default it's 6 seconds.

For JPEG thumbnails you may also specify their size.

Once you apply new setting, you must re-start your incoming stream on your encoder or origin server.

Related documentations

Live streaming in Nimble Streamer