July 30, 2020

Streaming SRT via OBS Studio with Nimble Streamer and Larix Broadcaster

OBS Studio team added support for SRT in their software recently. That is a great improvement and we highly recommend using that protocol for your delivery to and from OBS.

In this article we're going to show how you can use OBS with two products of our team. Here are the scenarios we'll cover:
  1. Set up OBS Studio to receive SRT.
  2. Set up Larix Broadcaster to send SRT to OBS Studio.
  3. Set up OBS Studio to send out SRT stream.
  4. Set up Nimble Streamer to receive streams from OBS Studio.
This will make a complete pipe from your mobile device through OBS to a software media server located wherever you need it.

Notice that points 1 and 2 are also covered in our video tutorial about streaming SRT to OBS from Larix Broadcaster and Screencaster, you can also watch it below.

We assume you already installed all three products: the latest version (25.0.8+) of OBS on your local computer, Larix Broadcaster on your mobile and Nimble Streamer on one of your servers.

Set up Larix Broadcaster

Open Larix Broadcaster, click on gear icon to enter Settings menu. Tap on Connections.

In our example we already have some connections so let's add a new one by tapping on New connection.

Name field can be defined to distinct a new connection from existing ones.
URL field has to be similar to "srt://" - that is your computer IP and the port which you defined on previous step.

Save setting to see it in the list, then tap on its check box. This will enable this connection for streaming.

Now you can get back to video preview and tap on big red Recording button to start streaming to OBS.

Please refer to Larix documentation reference page for other articles and videos of Larix setup and usage.

Set OBS for SRT input from Larix Broadcaster

Open OBS and check Sources area.

Add new or change existing Media Source.

Enter a URL like this into Input field.
In our case is the IP of your computer. You need to change IP address to the IP of your own computer. If you'd like to use some other port, you need to change it as well.

Don't forget to allow incoming UDP traffic in the firewall settings for the specified port.

That's it, click on OK to save the media source. If you have Larix Broadcaster streaming, you'll see the picture.

Video tutorial

Also, take a look at the following tutorial of Larix Broadcaster and Screencaster setup for OBS Studio streaming.

Set OBS for SRT output to Nimble Streamer

Once you have some stream in your OBS, you can publish it to Nimble Streamer. Here's what you need to do for that.
Here are the steps to follow:
  1. Go to File -> Settings menu.
  2. Open Output tab.
  3. In Output mode field choose Advanced.
  4. Choose Recording tab.
  5. Select Type as Custom Output.
  6. In FFMpeg Output Type select Output to URL.
  7. In output URL enter "srt://" or IP/port which you're going to use with Nimble Streamer - we'll define that in the next section. In this example is the IP address of your Nimble Streamer instance.
  8. Set Container format to "mpegts".
  9. You can use default encoders and decoders, or select the one you want to use, such as libx264.
Here are the settings we have as we complete them:

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

Set Nimble Streamer

Nimble Streamer has full support for SRT. This article describes full SRT setup in Nimble Streamer and you should refer to it for all details.

Now open Nimble Streamer -> Live streams setting menu, choose MPEGTS In tab and click on Add SRT stream button.

You see this dialog:

Here's what we do in our case:
  1. Set Receiver mode to Listen.
  2. Local IP can be set to "" to process streams from all interfaces.
  3. Local port should be whatever you can use on your server. In our case it's "2020".
  4. Alias can be set to something you will see for this stream identification going forward in setup.
  5. If you click on Add outgoing stream and enter app and stream name, WMSPanel will create the outgoing stream automatically using the names which you provided.
Once you save, you'll have it all set.

To start streaming from OBS, pressing Start Recording button.

Once you do that, Nimble will provide the outgoing stream.

E.g. if HLS is enabled for this server instance, your HLS stream URL would be

If you need to make further streaming via RTMP, check RMTP digest page and related articles there like RTMP republishing setup.

Please refer to full SRT setup instruction to see what else you can do with SRT setup or further re-streaming. Also, check Glass-to-glass delivery setup to see another example of SRT usage with our products.

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Related documentation

July 29, 2020

Slice-wide permissions in WMSPanel

WMSPanel cloud service provides full set of capabilities for controlling Nimble Streamer behavior as well as reporting its stats. The main instrument to split stats is a data slice which allows defining servers and respective applications or streams to get stats from.

The hierarchy of users in WMSPanel account is simple - admin users ("admins") can do anything, non-admin users (or "users") are allowed to see the stats in the data slices where they are assigned. However if you need to give some non-admin a permission to do something with server setting, you can define individual permissions, it's described in this article.

There are cases when you need to define some set of permissions to an entire set of non-admin users.

Now WMSPanel provides this option using data slices. The main idea is as follows:
  • Create a slice.
  • Assign a set of servers which you want to give control to.
  • Assign non-admin users which you want to give permissions to.
  • Define permissions.
Those permissions will be applied to all users and they will be allowed to make specific set of operations over the servers assigned to this particular slice.

When a non-admin user switches to particular slices, he or she gets access to servers and as allowed by slice' permissions list.

Data slice permissions and per-user permissions (defined as described here) are combined together in a white-list manner. So, if you set "Incoming streams" in per-user permissions list and "Outgoing streams" in a data slice permissions list, a given user will access incoming streams in any slice and outgoing streams in that particular slice only.

We strongly recommend to enable 2-factor authorization for all admin users and non-admins with special set of permissions to improve the level of your security.

Let's see how it's set up.

Go to slices management page by clicking on Manage link under the top menu. Create a new slice if you haven't created it yet.

For the designated slices, click on "gears" icon on the right from the slice details, it's there among other icons. You will see a dialog like this.

Once you click on "0 permissions" you'll see a list of permissions for a particular server. Just click on check boxes for required features.

You can do that for all servers from those assigned to the slice.
Clicking on a check box near server name checks all features.

That's it. Once you save settings, they will be applied to your slice and your users will be able to use selected features.

Secure your account in 3 easy steps
 article gives more ideas about working securely in WMSPanel.

Related documentation

July 23, 2020

Vote! Streaming Media European Readers' Choice Awards 2020

Streaming Media European Readers' Choice Awards of 2020 is now opened for voting. Softvelum products are represented in 4 categories:
  • Analytics/Quality of Service Platform: Softvelum - Qosifire
  • Encoding/Transcoding Service: Softvelum - Nimble Live Transcoder
  • Hardware/Software Server: Softvelum - Nimble Streamer
  • Mobile Video App or Solution: Softvelum - Larix Broadcaster

Here's where you can find us:

Support our team by giving your vote for us!

July 16, 2020

NDI support in Nimble Streamer

NDI® is a free protocol for video delivery over IP. It's widely adopted by industry professionals in a variety of products used in live production.

NDI is a technology which was implemented with these ideas in mind:
  • Live video is produced and processed by professional production teams in local networks prior to outer-world delivery.
  • Various solutions from various vendors are fully interoperable using the same protocol.
  • Network topology doesn't matter, making it easy to find and capture video streams.
  • Video source is abstracted from video destinations, it just sends out the data into the network.
  • The video content is moderately compressed with 10x factor down to 100 MBps making it easy to deliver over local networks.
  • It's a replacement for SDI technology.

1. Nimble NDI features overview

Softvelum Nimble Streamer software media server is used by a lot of customers from live production industry for efficient delivery of live streams among production sites and from production to the viewers using all general-purpose protocols like SRT, RTMP, MPEG-TS and others.

Now NDI is available in Nimble Streamer to provide even more capabilities for live delivery.

Receive NDI signal as input. Nimble gets the stream and decodes it for further usage. You can do various further processing:
  • get NDI from local network;
  • transform with Live Transcoder: re-sizing, re-sampling etc
  • encode into H.264/AVC, H.265/HEVC, VP8, VP9 with supported encoder libraries;
  • re-package into other protocols for further delivery: SRT, HLS, MPEG-DASH, RTMP etc;
  • record and play with DVR;
  • handle heavy duty when serving streams to multiple viewers.
Send NDI signal as output. Nimble produces an NDI stream:
  • take any content input via supported protocols like SRT or RTMP;
  • transcode and send the content via NDI into local network.
So Nimble Streamer is not a production-level mixing and editing tool but rather is a "bridge" between live production environments and global networks.

NDI monitoring tool. Along with implementing NDI in Nimble Streamer, we've made a console tool for diagnosing NDI streams. This helped us test and debug our solution, so we are sure it also will help our customers debugging their setup of Nimble and NDI streams in general.

Now let's look at NDI setup and usage in our products.

2. Installation

Handling NDI requires Live Transcoder for Nimble Streamer because the streams must be either decoded from or encoded to NDI format.

So before moving forward, you need to install the following products of Softvelum and make subscription where it's required.
  1. Sign up for WMSPanel account.
  2. Install Nimble Streamer on a proper server and register it in WMSPanel. If you'd like to install SRT package, please also refer to proper instructions.
  3. Subscribe for WMSPanel account, the price starts from 30 USD per month.
  4. Create Live Transcoder license and subscribe. This short video shows the process. It costs 50 USD per month per server.
  5. Install Live Transcoder package and register the license on the server with Nimble Streamer instance.
Once you're finished, you will have a paid WMSPanel account, a running instance of Nimble Streamer with Live Transcoder package, ready to transcode streams. For more details about Live Transcoder usage please refer to documentation reference and our video tutorials.

3. Set up NDI input

To get the NDI stream in, you need to create a Transcoder scenario. In your WMSPanel account, click on Transcoders menu to open scenarios page, then click on Create new scenario button. You'll be redirected into an empty scenario.

Now drag a blue video source element, then select NDI option.

In NDI name field you need to enter your source NDI stream. It can have both host name and stream name, but you may use just stream name. In our example the NDI source is "SOURCE HOST (stream)" which means host ("SOURCE HOST") and stream name ("stream"). Please also check NDI tool described in section 5, its output provides NDI source names which you can use for your input.

Now you can create the video output element, just drag the green element and keep the output type as "Stream".

Application and stream name define the naming of your output stream for further reuse. You may leave other values by default if you find them appropriate or define other parameters and values, like different codec or encoder library. Once you save encoder settings, you need to link decoder and encoder elements, just drag an arrow from the decoder to the encoder.

You may also put any filters between decoder and encoder in case you need to additionally transform the content, like to split the stream and make various renditions.

Once you're done with video pipe, you need to do the same for audio part of your input content. Drag audio source and select NDI stream as input. You need to define the same input stream name as you did for video.

Now add audio encoder element.

Here you specify the same output app and stream name, then you may choose codec and encoder. Once you save settings. You need to connect decoder and encoder, unless you want to apply some filters like volume changer.

That's it. Now once you save scenario, it will sync up with Nimble Streamer within several seconds and your server instance will start receiving NDI stream to process it and generate the output stream.

You can now handle this stream according to your use case, like re-publish it via SRT or RTMP. The SRT publication setup is described in this article and RTMP re-publishing described here.
You can also try playback to make sure the stream is available. The example of HLS output stream URL will be http://yourhost/live/output/playlist.m3u8 for default settings.

In addition to the aforementioned "direct output" transcoding pipe, you can add more filters and generate multiple outputs. Check this scenario example.

It has video split filter after NDI decoder, then it makes direct output with original rendition, scales down to 480p and down to 240p, and encodes all 3 outputs. The decoded audio is also split into 3 output streams.
You can also check other examples of transcoder workflow in our YouTube playlist.

4. Set up NDI output

Setting NDI output is somewhat similar to input setup process.

First, make your live stream input available for further processing, read our documentation for details:
You can check other protocols and use cases on live streaming digest page.

Once you have your input stream ready and tested, you can proceed with NDI setup.

Go to your transcoder setup and create a new scenario.

Video input will have your processed incoming stream application and stream name. You may choose another decoder if you want as well.

Drag and drop encoder element and select NDI as output option.

Now specify output stream name, this is how it will be recognized by other NDI recipients in this network. You may also define this stream's key frame alignment.

Save this and connect video input and output. 

Now add audio input having the same stream app and stream name.

Then add encoder element with NDI selected in it.

The stream name needs to be the same as you specified in video output. When you save audio output, connect input and output.

When you save this scenario, it will be synced within several seconds.

Once the scenario settings are synced, your Nimble Streamer will start sending NDI output with the content defined by our scenario.

Just like you saw in section 3, you may create more complex scenarios.

In this example the audio in encoded without changes while the video is scaled down and then custom "fps" filter is applied to change the framerate.

5. NDI monitoring tool usage

In addition to implementing NDI in Nimble Streamer and Live Transcoder we've created a tool which helped us debugging NDI workflow. It's a command line utility called "nimble_ndi". It works if Nimble Streamer and Nimble Live Transcoder are installed with no need for registering Nimble instance or Transcoder license.

It provides two functions: getting the list of available streams and getting full details about a particular stream.

5.1 Get active NDI streams list

Log into the server where Nimble Streamer is installed and run this command:
It will show the list of streams as "host name (stream name)" with IP and port, e.g.

camera1 (stream)        
camera2 (stream)        
producer (main)         
producer (secondary)    
OSA-VM-WIN10 (vMix - Output 1)
OSA-VM-WIN10 (vMix - Output 2)
That information can be used as a reference for NDI setup in previous sections. For example, having this output, you can use host and stream ("OSA-VM-WIN10 (vMix - Output 1)") for your NDI input setting.

5.2 Get NDI stream details

If you want to have full info on the frames of specific stream, run this command:
nimble_ndi --show-frames="host (stream)"
nimble_ndi --show-frames="camera1 (stream)"
It will produce the output like this:

video: timecode=107080000 timestamp=15943425579304024 av_sync_ms=0 fps=24/1
audio: timecode=107310000 timestamp=15943425579707145 av_sync_ms=40 no_samples=1024 sample_rate=48000
audio: timecode=107520000 timestamp=15943425579708666 av_sync_ms=40 no_samples=1024 sample_rate=48000
video: timecode=107500000 timestamp=15943425579712332 av_sync_ms=0 fps=24/1
audio: timecode=107730000 timestamp=15943425580115564 av_sync_ms=40 no_samples=1024 sample_rate=48000
audio: timecode=107950000 timestamp=15943425580117047 av_sync_ms=40 no_samples=1024 sample_rate=48000

Each line represents a frame of either video or audio with these parameters:
  • timecode: it's optional but Nimble generates it for he tools which need it;
  • timestamp: time which NDI library provides us with;
  • av_sync_ms: a delta from previous frame of either video or audio, in milliseconds;
  • no_samples: number of audio samples, it's for audio frames only;
  • sample_rate: it's audio frames only;
  • fps: for video frames only.
That allows easily tracking NDI streams in your network.

6. Using NDI Discovery Server

Nimble Streamer can work with NDI Discovery Server and if you want Nimble to work with it, you need to specify it in ndi-config.v1.json by its address.
You can find this file at these locations:
  • On Windows it's %PROGRAMDATA%\NewTek\NDI\ndi-config.v1.json
  • On Linux it's $HOME/.newtek/ndi-config.v1.json
In order to specify NDI Discovery Server, you need to open ndi-config.v1.json, find "networks" section and add "discovery": "discovery.server.I.P" parameter. Here, discovery.server.I.P is the address of a host where NDI Discovery Server is working. For example if you have it working on then your config will have this section:
"networks": {
      "ips": "",
      "discovery": ""

If you don't want to edit these files manually, use respective utils such as NDI Access Manager for Windows or Sienna Access Manager for Linux.

Notice that on Linux the NDI config files should be placed in the home directory of the user which Nimble is running as. For example, if Nimble is running as root, then the file must be located at /root/.newtek/ndi-config.v1.json

7. Video step-by-step tutorial

We've made a video showing the setup process, take a look at it.

Also, watch:

8. SEI metadata NTP sync-up

Nimble Streamer supports SEI metadata processing for synchronizing output NDI streams. Using this feature you can take multiple input streams and line them up to make in sync with each other which is important when you need to show the same event from different video sources.
This feature also allows forwarding SEI meta further.

9. Troubleshooting

Q: I setup NDI Discovery Server IP by the 3rd party software and nimble_ndi shows a list of NDI streams, but streams are not available for the Transcoder.

Make sure that the .newtek directory with the *.json config files is located at the home folder of a user which Nimble is running as.
In the latest NDI library releases NDI config files are also moved from .newtek to .ndi directory. Please copy ndi-config.v1.json file to the .ndi directory if NDI streams provided via Discovery Server are still not available. The full path to the config for the root user is /root/.ndi/ndi-config.v1.json

Q: I see stutter and dropped frames in NDI output

First, try to add the following line into /etc/nimble/nimble.conf and restart Nimble:
ndi_sender_cbr_enabled = true
If this doesn't help, switch from default RUDP mode to Single TCP for sending and receiving.

Q: I'd like to have NDI|HX® support

At the moment NDI|HX® support is not available on Linux.
On Windows it's available by default, no additional activities are needed.
NDI|HX® is intended to be used in mobile applications and uses H264 or HEVC. You can have NDI HX as a source, but Nimble doesn't use HX compression for NDI output.

Q: I have other problem

If you have any problems with NDI, check that your host is configured to have respective ports opened. Here's an example of UFW rules for Ubuntu host with properly configures ports.

> sudo ufw status
Status: active
To                      Action  From
--                      ------  ----
6960                    ALLOW
6961                    ALLOW
6962                    ALLOW
6963                    ALLOW
6964                    ALLOW
6965                    ALLOW
6966                    ALLOW

If you have other issues with NDI configuration, please refer to General NDI Troubleshooting page from NewTek knowledge base.

Contact us if you have any questions regarding NDI support in Nimble Streamer.

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NDI® is a registered trademark of NewTek, Inc.

Related documentation

July 8, 2020

Instant inactivity disconnect for SRT and other MPEGTS-based streams

Nimble Streamer supports a wide range of transport protocols which use MPEG-TS container such as SRT, RISTHLSMPEG2TS over UDP and over HTTP.

Part of default behavior for MPEGTS-based streams in Nimble Streamer is that when the input is interrupted for some reason, the output stream is still available. Here's an example. The SRT stream is published, then it's interrupted, however the HLS chunklist is still available having only old chunks.
This goes on until the 30 seconds timeout stops the stream, or the input is resumed.

There is now an option to interrupt the output streaming right at the moment when the input is interrupted. This is enabled on a server level via this config parameter:
mpeg2ts_instant_camera_remove = true
Read our parameters reference page for more details on operating server parameters.

This feature covers the following input protocols:
  • SRT input in all modes.
  • RIST input in all modes.
  • Pulled MPEG2TS over HTTP.
  • Pulled HLS.
The following protocols do not support this feature
  • MPEGTS over UDP, as there's no protocol capability for that.

Having that feature enabled, you will also be able to use Streams failover hot swap and Emergency streams hot swap features for on-the-fly transparent streams replacement.

Let us know if you have questions about this feature.

Related documentation

July 1, 2020

Q2 2020 news: SRT PASSet, RIST, DRM and Larix Broadcaster on Drafts

Softvelum team kept working during this intense Q2 of 2020 and we have several important updates for our products.

Nimble Streamer

First we'd like to address a Nimble Streamer issue which appeared back in May. Our external dependency package - libjson - introduced a fatal issue which caused multiple malfunctions across the entire Ubuntu users community. Within a few hours we detected a problem and released a fix which allowed us to overcome any consequences. We sent proper announcement to our Linux users so our clients got proper assistance on time, so most of them were not affected by this. 
That's just one of the advantages of being our subscribed customer.

Now let's see some new features.

Nimble Streamer SRT Publisher Assistance Security Set (SRT PASSet) is our new security and management framework for SRT. These are major capabilities:
  • Process incoming streamid.
  • Make per-server, per-application and per-stream authentication with user and password.
  • Apply any SRT parameters to every individual publisher and each individual stream.
  • Apply allow and deny lists for IP addresses on server and stream level.
  • Manage published streams via the publish control framework.
This provides our customers with great flexibility for publication control, especially for handling mobile publishers. Read these articles for more details:

Speaking of SRT, we've also added Forward Errors Correction support as part of our freeware feature set. FEC filter is still under development by the SRT community and we've added it per requests from our customers, so please use FEC filter feature at your own risk.

Nimble DRM has finally become available this quarter. It covers these features:
  • Google Widevine™ support to protect MPEG-DASH.
  • Microsoft Playready™ support to protect MPEG-DASH.
  • Apple FairPlay™ support to protect HLS.
  • Widevine Cloud Service support with key rotation.
  • EZDRM’s DRM-as-a-Service support for Widevine, FairPlay and Playready.
  • Verimatrix™ VCAS key management support to protect HLS with AES.
DRM is a premium feature set of Nimble Streamer.

Both SRT PASSet and Nimble DRM are part of Nimble Addenda - a premium package which also covers Nimble Advertizer. Package license costs just 50 USD per month per server and gives extended feature set with proper support.

RIST protocol support. A new protocol has been introduced by RIST Forum. RIST provides an open, interoperable and technically robust solution for low-latency live video over unmanaged networks.
Read this setup article to try it in action.

Last but not least, we've released an article on Handling fuzzy FPS to get proper bitrate output with some sources that produce streams with uncertain frame rate, like mobile encoders.

Larix Broadcaster

Our mobile team made a number of updates.

Larix Broadcaster app was mentioned in a few articles on SVG News:
Softvelum team was very proud to see Larix Broadcaster in such awesome use cases.

Now, let's look at new features.

We've released Larix Grove - an easy to use format which allows distributing streaming setup details. You use our web wizard to create a URL and a QR code to send to your publishers. It's supported in Larix for Android and iOS.

Larix Broadcaster for iOS is now able to provide Dual/Triple camera system support on iPhone 11+, including wide-angle and telephoto camera.
We also have multiple cameras streaming (via picture-in-picture and side-by-side) on modern supported devices in our beta version. You can use this link to install TestFlight and try it in action.

Larix for Android now has USB OTG camera support if the hardware vendors give that capability.
You can also go to Google Play and Join Beta to get early access to new features like multiple physical cameras on Android 10+.

Our YouTube channel also has a number of new videos explaining some of Larix features and other company updates

If you'd like to get our future news and updates, please consider following our social networks: Telegram channelTwitter, Facebook, LinkedIn and YouTube.