June 7, 2022

Manage client sessions using Nimble API

Nimble Streamer allows controlling end-user client sessions using various approaches.

The most capable approach is Pay-per-view framework which allows controlling the streaming process on per-stream and per-user level. You can use your own handler application with custom business logic to gather stats and block un-wanted viewers and listeners. Nimble sends data to PPV handler and acts according to the response.

Another approach is to use playback session authorization framework where Nimble communicates with custom handler app on each streaming session start. Nimble sends data about a connection being established and in response the handler returns the decision whether Nimble must allow or deny the new session.

Both solutions assume that Nimble will send requests to a handler and will get responses with some decisions regarding current sessions.


Now we introduce additional approach that works the opposite way, it uses Nimble Streamer HTTP API where you make calls to Nimble Streamer instance.

You make direct API call, get the list of active sessions and then make follow-up calls to deleted un-wanted sessions.

Initial setup

First, follow Pre-setup steps on API description page. This is required in order to enable and use the API. It needs a couple of parameters in nimble.conf file.

In addition you can secure your calls by using security token as described in respective section.

Get list of sessions

Use /manage/sessions method to get the list of current sessions as described in this docs section. In your response you'll get a JSON containing data of each session, including app and stream name, IP and some other parameters. Each session has its ID which you can use for terminating it.

Having list of all sessions, you can save it to your own database as well as make further decisions about each connection.

Delete specific session

If some clients need to be disconnected, you can call /manage/sessions/delete method with a list of session IDs that must be disconnected. Full description is available in this section

The HLS and MPEG-DASH clients will get 403 HTTP response while for other protocols (MPEG-TS/Icecast/RTMP/RTSP/SRT) they will just be disconnected.

This set of APIs provides a simple way to control Nimble Streamer playback. If you need more sophisticated way, check other approaches on top of this article.

May 4, 2022

WebRTC publish setup for Nimble Streamer

In memory of Alex Gouaillard
who inspired our team for WebRTC

WebRTC has become a significant part of live streaming landscape in various use cases and scenarios - from low latency streaming to live chatting. It's a big stack of technologies which are combined in various combinations depending on the problem which a customer needs to resolve.

Softvelum team got multiple requests from customers regarding WebRTC support and finally we came to a combination of proper technology pieces best fit for solving this task. The streaming tasks which our customers specifically wanted us to solve are related to easy ingest of live streams from any browser.

Current WebRTC support in Nimble Streamer covers the following:

  • Ingest of WebRTC live stream into Nimble Streamer.
  • WHIP is used for signaling, see details below.
  • H.264, VP8 and VP9 video and Opus audio input.
  • JavaScript client for publishing video and demo page with sample client.

Signaling is an important part of WebRTC stack because it defines how a client connects to the host or to another client. Nimble Streamer uses WebRTC-HTTP ingestion protocol (WHIP) for signaling. It's a standard with Internet Draft status and it's already used by various WebRTC products. So we decided to use WHIP to be compatible with as many solutions as possible.

Nimble Streamer uses Pion implementation of WebRTC API. Special thanks to Sean DuBois and all Pion contributors.

Output streams can be generated in all protocols supported by Nimble Streamer, e.g. HLS, SLDP, NDI, SRT, depending on output codecs and required transcoding, see more details below.

Let's go step by step to set up Nimble Streamer to receive WebRTC ingest.

Notice that currently only Linux version of Nimble Streamer supports WebRTC. We're working on Windows support.

1. Enable feature in Nimble config

First, you need to add a couple of parameters to nimble.conf to enable the feature. On Linux this file is available as /etc/nimble/nimble.conf. For more details about this file and its parameters, check Configuration reference page.

Add these parameters:

webrtc_whip_support = true
access_control_allow_headers = content-type
access_control_expose_headers = location

Then re-start Nimble Streamer instance. On Ubuntu it's done by this command:

sudo service nimble restart

Check installation instructions for other platforms.

2. Set up SSL for Nimble

The next step is to enable SSL for your Nimble instance as it's required for secure WHIP signaling.

You can set up your SSL certificate using this general instruction. You may obtain CertBot Let's Encrypt free certificate as we've described here.

For testing purposes you may create your own self-signed certificate but in order for it to work, you'll need first to open any https:// page like https://yourhost.com:port/ and accept security risk.

For production purposes in general, you need to have a valid SSL certificate. Also, your server must be assigned for the domain of this certificate.

Once you've set up SSL for Nimble, you need to test it. Open https://yourhost.com in your browser, where yourhost.com is the host of your Nimble. If you get error 404 and have no warnings from your browsers then your SSL was set up is properly and is working.

3. Set up WHIP client authorization

WHIP clients use URL parameters to pass their settings to the host.

WHIP client allows publishing from any browser to the server so Nimble Streamer requires to have user and password to be defined for the application where the publishing will be performed. If you don't set up a user/password credentials pair for the WHIP client and for the target application then your user won't be able to stream.

To set up an application, go to WMSPanel, open Live Streams Settings menu, choose a designated server, open Applications tab and create an application with required user and password.

In our example the app name is "live" and we'll use "whip" as stream name later on.

You may use two options to authorize clients on the server for publication.

3.1 Simple user/pass authorization

In your client publishing URL, use "whipauth" parameter to send credentials like this:


Where "live" is the name of the application with credentials.

Notice that whoever opens your publishing page, they can see your app name and user/password pair. This means high chance of leaking credentials for unauthorized publications. So use this authorization approach only if your debugging or if you provide separate applications for your trusted publishers.

In any other case, please use publish control framework.

3.2 Publish control framework

If you need more sophisticated authorization of your publishers based on your business logic, use Publish control framework. With publish control, you can prevent leaking of your publishing credentials. Also, you'll be able to get the status of all published streams and decline any of them any time.

When the setup is done, the URL will have "publishsign" parameter.


Read this setup article to get all details.

4. Codecs support

As was mentioned earlier, Nimble Streamer supports H.264, VP8 and VP9 video with Opus audio in WebRTC ingest. So if your client uses these codecs, Nimble will be able to process them and make proper output.

If you need your users to publish from their browsers only with certain video codec, you can indicate that by setting "videocodecs" parameter. E.g. to make server accept only H.264 you can set it like this:


If you are ready to accept either H.264 or VP8, use comma in that parameter's value:


5. Generating output

Once the content is ingested, Nimble Streamer provides the following options for further processing.

5.1 Direct output via limited protocols

If the ingest has H.264 and Opus codecs, Nimble Streamer will be able to generate H.264/Opus output via MPEG2TS-based protocols: MPEG-TS over UDP multicast, SRT and RIST, and played via VLC or ffmpeg.

5.2 Full-featured transcoded output

All input codecs - VP8, VP9, H.264 and Opus - can be transcoded into any other codecs. That includes H.264/AAC output that is a de-facto standard for Internet, as well as generate HEVC (H.265) video. 

Use Nimble Live Transcoder to transform the input with any variety of decoders and encoders, with software libraries, NVENC and QuickSync hardware acceleration.

Watch Transcoder video tutorials for more setup examples. For those scenarios, the WebRTC ingest will be just another input stream. Here is a simple example of a transcoder scenario with H.264 and AAC output.

You can then use any combination of live streaming output protocols and options, like HLS, SRT, NDI, SLDP, etc. Nimble Streamer transmuxing engine will provide any combination you need.

You can also record the generated content using Nimble Streamer DVR and then provide the playback using HLS and MPEG-DASH protocols.

5.4 Notice on packet loss

Notice that if a publishing client and your server are located far from each other or need to communicate via bad quality networks, then you should expect some video and audio frames loss. Protocols and players handle this type of frames loss differently. At this moment Nimble Streamer does not try to add fake video frames or audio silence to compensate that behavior.

6. Network-related and general parameters

By default, Nimble Streamer works in ice-lite mode

If Nimble server instance runs on a host with public IP address then additional configuration is not needed.

If a server instance runs on Amazon EC2 then you'll need to create an additional config file at /etc/nimble/whip_input.json and add the following JSON there:


where "a.b.c.d" is a public address assigned to AWS server instance. If it has multiple IP addresses, just add them in the same parameters separating by comma like this:


This file is processed by Nimble at the beginning of each new publishing session, so you can change it without re-starting the server.

To define ports range, you can also add these parameters:



In this case the candidates will be selected only from the range of ports 1000 to 40000.

If you use network parameters mentioned above, the combined JSON in this case will be:


In addition you can use this config file to define supported codecs on the server level instead of defining them per session using SupportedVideoCodecs parameter:


JSON format requires this kind of syntax and if you add them in different blocks or have no commas between parameters, Nimble will not process the config.

7. Browser publishing library and demo page

We've created a JavaScript library which you can use for adding publishing capabilities into your web pages. Use its code in your projects or take it as is for embedding into your pages to connect your users to Nimble Streamer.

There's also WebRTC publication demo page which uses that library to provide simple way to check your server setup. Just enter a WHIP URL with server address and publishing credentials, and then click on Publish. You will then be able to use your camera and microphone to streaming, and will see detailed logs of what's happening.

8. Video tutorials

Watch this brief tutorial demonstrating the setup process.

Also watch setup process to take WebRTC ingest and produce NDI output from it.

The following tutorial shows how to set up a Nimble Streamer to receive content via WebRTC and then send it as the UDP multicast into the local network without transcoding.

Our team keep improving WebRTC support in Nimble Streamer, so stay tuned for updates.

March 17, 2022

Quick URL Import

We’d like introduce our new improvement to the WMSPanel called Quick URL Import.

The Quick URL Import button in MPEGTS IN and UDP Streaming tabs in Live Streams Settings menu will help instantly transfer publishing or ingest URL from your stream provider to Nimble. Feel free to use it with UDP, HTTP, HLS, SRT or RIST protocols.

The standard URI is accepted as:

This will save your time on editing settings if you have stream URL with encoded parameter in the URL.

Quick import will recognize the stream protocol and additional parameters in the URL and the accepted parameters will be automatically filled as options in the corresponding fields.

For SRT, you may even use the streamid format proposed by the Haivision. The RIST URL syntax supported as described on this documentation page.

Just find a green Quick URL Import button on MPEGTS IN or UDP Streaming tabs.

Then fill in the URL. Depending on a protocol, a new window will appear after the Add setting button is pressed. As the URL is parsed, the parameters will be filled in the corresponding fields.

Add more parameters like stream name to have a complete setting and you're good to go with the streaming.

Related documentation

January 31, 2022

HEVC support for Widevine and PlayReady DRM in Nimble Streamer

Nimble Streamer DRM provides wide range of DRM encryption technologies and key management platforms.

Recently we've added support for H.265/HEVC codec for these encryption technologies:

They work for all major scenarios:

So you can deliver your un-protected stream into Nimble Streamer, convert it into MPEG-DASH or HLS fMP4, record into DVR if needed, encrypt and then deliver to your viewers for further playback. And if you have any VOD files, you can define transmuxing rules and then set up DRM so they could be played via DRM-powered players.

On the viewers' side, Larix Player for Android allows running MPEG-DASH streams via embedded ExoPlayer in all streaming modes and decode Widevine and PlayReady streams. You can download it on Google Play and visit Player website to learn more.

Feel free to try Nimble Streamer DRM in action and let us know of any questions.

Related documentation

Nimble Streamer DRM, Nimble Addenda package, Larix Player for Android

January 26, 2022

CEA-608 support in MPEG-DASH streams

 Nimble Streamer has wide support for MPEG-DASH live streaming, including subtitles processing.

When CEA-608 subtitles are integrated into a video track, most players require those subtitles to be declared in the manifest, otherwise a viewer cannot select them at all.

This tag is used in a manifest for the declaration:

<Accessibility schemeIdURI="urn:scte:dash:cc:cea-608:2015" value="CC1=lang">

where value contains the number of the track with subtitles and their language, e.g. "CC1=eng".

This option can be set in server settings under Nimble Streamer / Live Streams Settings menu in Global  tab in CEA-608 settings field.

This setting is applied to live and DVR output streams.

The format is as follows:
<app1>[/<stream>]:N=<lang>[;N=<lang>] <app2>[/<stream>]:N=<lang>[;N=<lang>]
Each new application is separated by a space. Here's an example where all streams for "live_app" application will have first track with Russian subtitles:

The setting is simply "live_app:1=rus". This is what you'll see in a manifest:
<Accessibility schemeIdURI="urn:scte:dash:cc:cea-608:2015" value="CC1=rus">
This is how you'll see it in your player:

You may combine settings for multiple apps and streams, e.g.
live_app:1=eng;2=rus live_app2/stream1:1=eng;2=fra
will set two tracks for all streams in "live_app" application and also will define two tracks for a single "live_app2/stream1" stream.

If you want to set a setting for entire server, just skip "app=" part, e.g. set parameter to "1=eng"

Related documentation 

Nimble Streamer MPEG-DASH features

January 12, 2022

Server playlist support for live steams input

Server playlist feature set for Nimble Streamer was introduced to provide capabilities to create output live streams from a set of VOD files.

Now Server playlist got a couple of more features to improve it:

  • take live streams as input for playlist entries;
  • define default streams in case current playlist entry is not available.

Notice that new features do not change the playlist's basic principles and mechanics. They add new parameters as we describe below. So before reading about the updates, please get familiar with these materials:

Let's see what we've got.

Live streams input

You can specify any available live streams. So no matter where your live stream is coming from - RTMP, SRT input or a stream from Nimble Transcoder - you can use it as your source.

You need to prepare your content for playlist input and also additionally transcode it afterwards as we describe in section 2 "Preparing content" of Server playlist spec.

The semantics of live stream input is similar to VOD input: it's inserted among other entries in "Streams" block having "Type" parameter set to "live" as shown below.

  "SyncInterval": 5000,
      "Stream": "live/playlist",
      "Blocks": [
          "Id":"1", "Start":"2022-01-17 08:00:00",
              "Type":"vod", "Source":"/var/mp4/sample.mp4", "Duration":20000"
              "Type":"live", "Source":"live/stream", 

The following parameters can be used for live stream entry:

  • Source - input stream name, defined as "application_name/stream_name" as seen in output streams at Nimble Streamer live streams page.
  • Duration - the duration of the current stream.
  • TotalDuration is also supported but it means the same as Duration. If both parameters are set, the one with the smallest value will be used.

Default streams

If the current live stream which is supposed to be playing now, is unavailable for some reason, you may specify a default stream which will be played instead. A DefaultStream parameter can be defined on a block level as shown below.

  "SyncInterval": 5000,
      "Stream": "live/playlist",
      "Blocks": [
          "Id":"1", "Start":"
2022-01-17 08:00:00",
          "DefaultStream": {
            "Source": "live/default"

              "Type":"live", "Source":"live/stream"
              "Type":"vod", "Source":"/var/mp4/sample.mp4", "Duration":20000

This default stream may have "Type" parameter be either "live" or "vod". The "Source" defines where the content is taken from, see server playlist spec for details.

For VOD mode, it also supports "AudioStreamId" and "VideoStreamId" parameters to select a respective track if a VOD file has several tracks.

Playlist Generator

You can use our Playlist Generator to create a simple playlist using our UI wizard

Watch this video tutorial to see the setup process in action.

Let us know if you have any further feedback regarding the server playlist.

Related documentation

Server playlistGenerate NDI stream from local files via Server PlaylistWeb UI for Server Playlist

December 29, 2021

2021 summary: Nimble Streamer, WMSPanel, mobile SDK and more

Holiday greetings from Softvelum!

The year of 2021 has passed by and it's time to overview what our team has accomplished and what you might find interesting for your business.

But first, we're glad to recall that Softvelum became the finalist of 2021 Streaming Media European Readers' Choice Awards in Hardware/software Server category with our Nimble Streamer media server. Thanks to everyone who voted for us!

We've made a number of big and small adjustments, you might have seen them in our announcements in social media.
Here are the most notable updates.

WMSPanel: improved billing, cloud backup and more

WMSPanel cloud-based service was adjusted this year to make sure our customers can control their streaming infrastructure more conveniently and safely.

Improvements in billing mechanics of WMSPanel now allow combining billing for WMSPanel, Transcoder and Addenda licenses into single charges. The ability to receive up-front payments was updated per users' feedback to make it even more flexible. We've also supported PayPro Global - the second gateway so you could have an alternative destination for making payments.

Nimble Cloud Backup is another significant WMSPanel feature we introduced this year.
You can save streaming configs of your Nimble Streamer instances into our distributed cloud database to improve redundancy. Then if you need to get back to some version of their cloud backup, you can restore it within WMSPanel account as a new server instance. Learn more about Cloud Backups and try it in action.

Cloud technology users are always concerned with security. Take a look at our latest Secure your account in 3 easy steps article showing how you can use users management, two-factor authentication and cloud server backup to make sure WMSPanel is safe from multiple directions.
Speaking of security, one of the most frequent questions these days was:
Do we use log4j?
The answer is no, we do not. None of our products use it so there's no need to worry.

Nimble Streamer

Nimble was in focus of our team: we were improving existing and adding new features.

Server playlist was introduced for Nimble Streamer.
You can create live streams by composing VOD files into playlists to produce single live stream. The playlist is a JSON file with a simple grammar which allows setting streaming scenarios of various complexity.
We'll soon release live streams support for playlist insertion in addition to VOD.

Nimble Streamer Advertizer has been significantly improved per our customers' feedback.
  • VOD server-side ads insertion is working. At the moment, HLS output with MPEG-TS and fMP4 containers is supported. Take a look at VOD SSAI overview article and also read 
  • Per-session ads can be inserted using your own session handler. It allows making per-session ads insertion for each individual user by using customer-side session handler. You can also get per-session statistics to accumulate ads insertion metrics for advertisers' confidence.
  • Local ad files and local config can be used. Watch Add pre-roll ads easily video tutorial showing that case.

Live Transcoder has a few updates including these:
  • Conditional transcoding allows enabling pipelines based on incoming stream's resolution. You can set a condition based on height and/or width thus avoid unnecessary waste of your server resources. This is especially useful for creating ABR live streams.
  • NETINT hardware encoder can now be supported via custom FFmpeg build, please read this post describing this approach.
A small but important feature for those who may concern: KLV metadata is now supported in Nimble Streamer.

Templates and configs for Zabbix monitoring of Nimble Streamer and SRT streams are now available along with a tutorial video about it. System administrators can now add their media server to their Zabbix to keep tracking live streaming parameters of Nimble instances as well as SRT-specific stats.

SLDP protocol is being actively used by our customers to provide low latency playback. Recently we've made a simple mosaic videowall demo page which allows playing 4 streams simultaneously. You can make your own mosaic using reference simplified version on our github.

Last but not least, Nimble Streamer is now available on ARM64 platform. Take a look at this tab on installation page to see instructions for Raspbian and Ubuntu 20.04 for ARM64.

Larix Broadcaster and Larix Player

Our mobile products - Larix Broadcaster and Larix Player - were actively used through the year by multiple users.

We released SDK for Android and SDK for iOS pages with architecture overview of Larix Broadcaster to make it easier to understand for beginners. They also refer to apps' sample code available on github.

Larix Broadcaster now supports Talkback feature set, which is the ability to get an audio return feed. So while you generate a stream, you may get audio stream via SRT, RTMP, SLDP or Icecast. This is a great feature for those creators who need to get a word from their studios while streaming live. Watch a third-party on Talkback and Vmix video tutorial on that.

Image overlays were implemented in Larix Broadcaster for both platforms. Take a look at our video tutorial showing overlays in Larix for iOS as an example of setup.

We've also introduced stand-by mode in Larix Broadcaster. When the stream hasn't been started, just long tap on Start, this will start stream in pause mode, image and sound will disappear while the stream is running. Meanwhile you may wait for a talent to appear or re-set the scene.

React Native: notice that we're currently working on React Native version of our streaming SDK. Contact us if you'd like to get early access for it.

For those of our users who use our apps on a daily basis we compiled our Best practices for Larix Broadcaster production deployment guide describing what might be useful in various scenarios.

Take look at docs reference page for more articles and videos about our mobile products. Also, our roadmap page contains our future plans on Larix product family development.

YouTube channel updates and our social media

This year we also posted a number of videos on our YouTube channel. Here are some most notable videos:
In addition, we got more videos about mobile products as well.

We also keep track of interesting third-party videos about using our products. Please check Reviews playlist with full list.

Another social media activity that we've made was the move of our github repositories.
We've made Softvelum github account which you can follow up to track our open source activities.

Last but now least, you can follow us any way you like for future updates via TwitterTelegramFacebookRedditYouTube and LinkedIn.

That's all for now.

Our team wishes you a Happy New Year and we'll see you in 2022!

December 23, 2021

Deliver SRT to multicast UDP MPEG-TS

We have released a new video tutorial about delivery of SRT across servers and transforming the content into multicast UDP MPEG-TS

It shows how to deliver live stream is the following scenario:

  1. Get two programs from MPEGTS UDP stream.
  2. Deliver it via SRT from AWS Nimble server to bare metal instance across the internet.
  3. Generate multicast UDP MPEG-TS on the second server for both programs.

Follow our YouTube channel to get more videos.

December 9, 2021

Improvements in billing mechanics of WMSPanel

Our team has recently made a few updates and improvements for the billing of our customers which will make it easier to handle. Please check what might be useful for you.

Combined billing for WMSPanel, Transcoder and Addenda

Previously, if customers wanted to add licenses for Transcoder or Addenda, they needed to create separate subscriptions for each type of license.

Our team has improved license subscription mechanics. For all new customers of Transcoder and Addenda who haven't had active licenses, WMSPanel subscription now allows to add Transcoder and Addenda licenses costs to panel's services.

Once you create new licenses, you will need to pay initial license fees proportional to the number of licenses and the number of days left until the next billing period of WMSPanel. At the nearest billing date you'll be charged with your usual WMSPanel cost options (servers, slices, stats) plus full monthly cost of all active licenses. If you cancel a license between billing dates, its cost will not be charged at the next payment date.

This way our customers will have a single payment every month instead multiple payments.

If you have separate legacy subscriptions for panel and licenses and you want to combine them into one, let us know about it so we could help you to transition.

PayPro Global payment gateway

Many of our customers already use it but we'd like to remind about this once again.

WMSPanel can be paid via the second payment gateway, PayPro Global. It allows a payer to control payment method, handle subscription email and billing addresses without the need for contacting support, and also view original invoices first-hand.

Up-front payments

Another option that we'd like to remind about is up-front payment.

We may accept a payment up-front, usually it's equal the price of 12 months of service with current amount of servers and options. The charged amount is put on your account credit. Every month a cost of your monthly services is withdrawn from your credit. If your monthly cost changes, then the cost of withdrawal is updated accordingly. The respective notifications about price change and credit charges are sent to the user. All charges also appear in "Payments and Invoices" tab of settings menu.

Transcoder and Addenda licenses will also be covered by account credit, just like it's done for regular subscriptions. When you create a license, we'll charge the license initial payments from your account credit.

Our team can enable up-front payment by request to our helpdesk.

If you have any further improvements which you'd like to have, tell us about that.

December 2, 2021

Local configuration and ad files support in Nimble Advertizer

Nimble Advertizer has become more flexible with the recent update.

Local config file

Instead of requiring a JSON config to be available via HTTP/HTTPS URL, you can now store the config in a local file. So besides handler app and static config available from a remote source, you can simply put your JSON config on a local hard drive where Nimble Streamer is installed. Nimble config will contain "file://" scheme location in "advertising_url" parameter.

Local ads content

Previously we required your ads to be available via URL. Now you can also put them locally on a Nimble-powered server and refer to them via "file://" scheme.

Video tutorial

Check this video showing both features in action:

You can read full Advertizer tech spec for detailed description and example of usage.

Let us know if you have any further questions.