2019 Q2 summary

Our team has been working on improvements through Q2 of 2019 so let's see what we've accomplished.

Qosifire

Last quarter we've introduced Qosifire live streaming monitoring service. It allows tracking availability and consistency of HLS, RTMP and Icecast live streams. The HLS support was added this quarter, take a look at this page for more details and also watch this video on our channel showing this feature in action. We've also added debugging capabilities for HLS - you can track DTS/PTS timestamps and see their dynamics real-time. Read this article and watch this video for more details.

If you still haven't tried using Qosifire, read why Qosifire might be useful for you and how you can get started with Qosifire, the step-by-step guide to using our quality monitoring control.


Products snapshots

We've added a couple of new pages in our gallery of Softvelum products snapshots which show how you can use our products for building your streaming infrastructure.

• Adopting Softvelum products step-by-step give a roadmap for trying our products and increase their usage gradually. It helps beginner users to get familiar with available capabilities.
• Building online radio about how to use our products to process, deliver and control audio streaming.

Nimble Streamer and more

Nimble Advertizer, our server side ads insertion framework, now has SCTE-35 markers support. So now ads insertion time point can by defined by absolute and relative time as well as SCTE-35 markers.
Also, Nimble Streamer transmuxing engine now supports passthrough of SCTE-35 markers during live streaming.

The Advertizer now also allows using AAC and MP3 containers for advertisement files during audio-only streaming. Take a look at Advertizer tech spec for more details.

We have some updates for SRT users of Nimble Streamer:

• SRT packet loss for Sender in Listener mode has been fixed. Read this article for more details and upgrade your SRT package.
• SRT sender "maxbw" parameter is highly useful for preventing from excessive bandwidth usage during lost packets re-transmission. We recommend using it for all streams on sender side. Read this article for more information.
• SRT "latency" parameters is also very important for re-transmission control and it should be used with "maxbw". Read this article to find out more.

If SRT technology is part of your streaming infrastructure, please read those articles to be up-to-date with latest improvements.

Nimble Streamer now supports RTMP republishing into Limelight Networks, Inc. Realtime Streaming service, take a look at Realtime Streaming Guide for setup details.

We've also improved RTMP to support HEVC for Nimble Streamer and Larix Broadcaster. This is an experimental non-standard feature available in limited number of players.

Starting from May 1st, Facebook deprecates the usage of RTMP and requires RTMP over SSL (RTMPS). And we've glad to confirm our Nimble Streamer and Larix Broadcaster products have full support for RTMPS.

Streaming to social media becomes more and more popular so we've made a couple of articles about that.

• Streaming from Larix Broadcaster to Facebook Live
• Streaming from Larix Broadcaster to YouTube Live

We have also collected all documentation for Larix applications in documentation reference page.

Another big update of Larix Broadcaster for iOS and Android and Larix Screencaster for Android is the release of adaptive bitrate (ABR). ABR (adaptive bitrate) is available in 2 modes:

• Logarithmic descend - gracefully descend from max bitrate down step by step.
• Ladder ascend - first cut bitrate by 2/3 and increase it back to normal as much as possible.

You can visit Larix website to find out full feature set.

Last but now least, take a look at The State of Streaming Protocols for Q2 2019 with RTMP declining and HLS going up.


We'll keep you updated on our latest features and improvements. Stay tuned for more updates and follow us at Facebook and Twitter to get latest news and updates of our products and services.

The State of Streaming Protocols - 2019 Q2

Softvelum team continues analyzing the state of streaming protocols. It's based on stats from WMSPanel reporting service which handles data from Wowza Streaming Engine and Nimble Streamer servers - there were 4000+ servers on average this quarter. WMSPanel collected data about more than 14 billion views. Total view time for our server products is 2 billion hours this quarter, or 21+ million view hours per day.

Let's take a look at the chart and numbers of this quarter.

You can see HLS share has increased to 78% with RTMP going down to 7%. People are moving towards de-facto standard of delivery, and they are also shifting from RTMP due to its future decline.

The State of Streaming Protocols - Q2 2019

You may compare that to the picture of Q1 streaming protocols landscape:

The State of Streaming Protocols - Q1 2019 

We'll keep analyzing protocols to see the dynamics. Check our updates at Facebook and Twitter.

If you'd like to use these stats, please refer to this article by original name and URL.

Efficient usage of SRT latency and maxbw parameters

We continue educating streaming people on SRT protocol usage. It's a streaming protocol which adapts to the network conditions, helps compensate for jitter and other fluctuations with error recovery mechanism to minimize the packet loss. This leads to the lost packets re-transmission, which increases the bandwidth usage between sender and receiver.

We'll take a look at "latency" parameter which is tightly related to the re-transmission process in general.

The "latency" parameter specifies the delay which is used if the packet reached the destination quickly (and therefore it's way ahead of "time to play"). But when the packet was lost, this gives it an extra time to recover the packet before its "time to play" comes. Original packet delivery takes some round-trip time (RTT), so it will take another RTT to send the correction. And if some issues happen again on its way to receiver, the sender will re-transmit it again and again until it's correctly delivered, spending time during this process.

So too small value of "latency" may cause the denial of re-transmission. Let's suppose you have some RTT from sender to receiver equal 200ms, and your "latency" is set to 300ms. Obviously, the receiver won't be able to get any re-transmission in case of first transmission because the latency "window" will close.

The SRT community recommends setting "latency" as follows:

• Your default value should be 4 times the RTT of the link. E.g. if you have 200ms RTT, the "latency" parameters should not be less than 800ms.
• If you'd like to make low latency optimization on good quality networks, this value shouldn't be set less than 2.5 times the RTT.
• Under any conditions you should never set it lower than default 120ms.

The "latency" value can be set on any side of transmission:

• sender;
• receiver;
• both sides.

The effective latency will be the maximum value of both sides, so if you don't set it on sender (so it'll have default 120ms) and 800ms on receiver, the active value would be 800ms.

We've previously shown how you can control the maximum bandwidth available for transmission over SRT using "maxbw" parameter. As you can see, you need to be aware not only about the bandwidth on your sender, but also latency settings.

So we highly encourage you setting both "latency" and "maxbw" parameters during SRT setup. Otherwise you will face one of these issues:

• When you set "maxbw" to cover all network problems, the latency can be too low to tolerate the losses.
• When you set proper "latency" without "maxbw", it will cause exhaustion of bandwidth.

If you don't know the exact values of your expected bandwidth, please set maxbw to 0 to let the SRT library auto-select bandwidth efficiently and handle re-transmission of lost packets.

Both configuration options are available for SRT setup in Nimble Streamer.

Please refer to SRT setup article to get familiar with the general setup process. Once you complete all required steps, use custom parameter fields to define appropriate entries as shown below.

The "maxbw" is defined in bytes per second, NOT bits per second. So if you'd like to set maximum bandwidth to 2Mbps, you'll have to specify 250000 as your designated value. This is an SRT-specific approach to value definition. The "latency" is defined in milliseconds.

Larix Broadcaster mobile app allows streaming via SRT with defined "maxbw" and "latency" as well.

If you have any questions regarding SRT setup and usage, please feel free to contact our helpdesk so we could advise.

Check out SRT support in Softvelum products to see what might help your company to utilize SRT the best way.

Follow us in social media to get updates about our new features and products: YouTube, Twitter, Facebook, LinkedIn, Reddit, Telegram

Related documentation

Nimble Streamer SRT feature set, SRT setup in Nimble Streamer, SRT FEC (forward error correction) in Nimble Streamer, Haivision blog: Reliable Low Latency Delivery with SRT+SLDP, Glass-to-glass SRT delivery setup, SRT in other Softvelum products

Inserting ads by Nimble Advertizer using SCTE-35 markers

Nimble Advertizer is a server-side ads insertion framework for Nimble Streamer. Its business logic may be defined by both a dynamic handler and a pre-defined config, you can find full tech specification here.

Ads insertion time points within a live stream can be set in 3 ways:

1. Specify the exact moment of time in GMT.
2. Time spots relative to the beginning of the viewing session.
3. According to SCTE-35 markers from the original stream.

The SCTE-35 markers are part of original streams delivered via MPEG-TS and HLS streams which Nimble Streamer is able to accept for input.


Before you start using SCTE-35, you need to add the following parameter into Nimble Streamer config file:

scte35_processing_enabled = true

You can read this page to find out how exactly you can make changes to Nimble Streamer config.


Here's a brief summary of how Nimble Streamer handles the markers for ads insertion:

1. You create a handler app which will tell Nimble how to operate ads. This may also be plain JSON file with static pre-defined setting. Advertizer spec described handler in more details.
2. Nimble Streamer processes incoming MPEG-TS and HLS streams with SCTE-35 markers to get the original content.
3. Nimble Advertizer calls your handler app or static config and gets response with ads scenarios.
4. Advertizer gets files with ads content to process them via Nimble Streamer according to ads scenarios logic defined by handler response.
5. If the handler response defines that current stream needs to insert ads according to SCTE-35 markers (by using "time-sync":"scte35" field), Nimble inserts the ads into original media right at the time points specified in SCTE-35 marker.
6. You can use this file as example of handler response which defines the usage of markers.
7. End user connects to Nimble and watches media stream containing original content mixed with advertisements. The ads will be inserted at full length, e.g. if your ad file is 30 seconds, the viewr will watch it all and then will see the original stream.

You can find example of handler response with marker-based insertion as well as other samples in Advertizer github repo. You can read all information regarding Advertizer usage on its website.

You may also insert SCTE-35 markers any moment to trigger ads insertion or pass them though for further use.

Also, check this: PlayDeck made a tutorial of how to generate SCTE-35 markers from their product and use them with Nimble Streamer HLS output.

If you find any issues with SCTE-35 ads insertion, please file us a support ticket so we could help you.

Related documentation

Nimble Advertizer, SCTE-35 markers forwarding and passthrough, Trigger SCTE-35 marker insertion by Nimble API, SCTE-35 markers support in Nimble Streamer Playout

Streaming from Larix Broadcaster to YouTube Live

YouTube Live became extremely popular lately and many users of Larix Broadcaster for Android and iOS and Larix Screencaster for Android also started publishing live video there. We get questions about correct setup of Larix products so this brief instruction explains this process.

Larix Broadcaster supports AVC/H.264 and HEVC/H.265 codecs for ingesting into YouTube.

Read more about Enhanced RTMP spec adoption for more information.

To proceed with YouTube Live you need to get familiar with service setup using this support page. When you set up YouTube Live transmission, you get these settings:

Primary Server URL: rtmp://a.rtmp.youtube.com/live2
Stream Name: 1234-5678-abcd-efgh

Larix uses single line for target URL setup so just need to use URL+Key as your connection URL, like this one:

rtmp://a.rtmp.youtube.com/live2/1234-5678-abcd-efgh

From Larix UI perspective the setup is performed with the following steps. We assume you've installed Larix using links from this web page.

Open the app and click on gear icon to see the main menu. Go to Connections list.

Now click on New connection menu. It will open a new connection dialog. Enter any descriptive name for a new connection and then insert your connection URL.

One more tip specific for YouTube:

YouTube requires both video and audio in the incoming stream, so make sure you have Mode set to Audio + Video.

Once you save changes, a new connection will appear in connections list. To use this new connection for further streaming, just click on its respective checkbox.

Once you get on the main video preview screen, you can tap on big red circle to start streaming.

This setup is applicable to Larix Broadcaster for both Android and iOS, as well as to Larix Screencaster for Android.

Notice that if you need to send the ready-to-go setup instructions to your operator, you can use Larix Grove format for that.

Visit our documentation reference page for more setup information.

If you have questions regarding Larix Broadcaster or other mobile products, please contact us via our helpdesk.

Related documentation

Softvelum mobile solutions, Larix documentation reference page, Publish from Nimble Streamer to YouTube Live,

Streaming from Larix Broadcaster to Facebook Live

Facebook Live became extremely popular lately and many users of Larix Broadcaster for Android and iOS and Larix Screencaster for Android also started publishing live to Facebook. We get questions about correct setup of Larix products so this brief instruction explains this process.

When you set up Facebook Live transmission on Facebook setup page, you get these settings:

URL: rtmps://live-api-s.facebook.com:443/rtmp/
Key: 1310310017654321?s_bl=0&s_sw=0&s_vt=api-s&a=Abw47R4F21234567

Larix uses single line for target URL setup so just need to use URL+Key as your connection URL, like this one:

rtmps://live-api-s.facebook.com:443/rtmp/1310310017654321?s_bl=0&s_sw=0&s_vt=api-s&a=Abw47R4F21234567

Notice rtmps:// prefix and port 443 - Facebook now requires to use RTMP over SSL for live streaming. Our products have full support for it.

From Larix UI perspective the setup is performed with the following steps. We assume you've installed Larix using links from this web page.

Open the app and click on gear icon to see the main menu. Go to Connections then click on New connection menu.

It will open a new connection dialog. Enter any descriptive name for a new connection and then insert your connection URL.

Once you save changes, a new connection will appear in connections list. To use this new connection for further streaming, just click on its respective checkbox.

Once you get on the main video preview screen, you can tap on big red circle to start streaming.

This setup is applicable to Larix Broadcaster for both Android and iOS, as well as to Larix Screencaster for Android.

Visit our documentation reference page for more Larix setup information.

If you have questions regarding Larix Broadcaster or other mobile products, please contact us via our helpdesk.

Related documentation

Softvelum mobile solutions, Larix documentation reference page, Publish from Nimble Streamer to Facebook Live,

SRT sender max bandwidth

SRT is a streaming protocol which adapts to the network conditions, helps compensate for jitter, bandwidth fluctuations and has error recovery mechanism to minimize the packet loss.

These excellent features lead to the lost packets re-transmission, which increases the bandwidth between sender and receiver. This is why if the network conditions are bad enough, the re-sent packets may consume all available throughput.

As you cannot control the network environment completely, you should set up the maximum bandwidth available for transmission over SRT for every SRT sender. Even if your network is fine now, it's a good practice to prevent any fluctuations in the future.

This maximum bandwidth limitation is set up using "maxbw" parameter for SRT streaming.
It needs to be set on sender side.

We recommend having maxbw value twice as much as your stream bandwidth, e.g. if you send 1Mbps, your maxbw should be 2Mbps.

If you don't know the exact values of your expected bandwidth, please set maxbw to 0 to let the SRT library auto-select bandwidth efficiently and handle re-transmission of lost packets.

We also strongly encourage you to set both "maxbw" and "latency" parameters for streaming via SRT. Please read this article to learn more about this parameter.

Proper configuration option is also available for SRT setup in Nimble Streamer. First, please refer to SRT setup article to get familiar with the general setup process. Once you complete all required steps, use custom parameter fields to define appropriate entry as shown on the figure below.

Please notice that maxbw is defined in bytes per second, NOT bits per second. So if you'd like to set maximum bandwidth to 1 Mbps, you'll have to specify 125000 as your designated value. This is an SRT-specific approach to value definition.


If you have any questions regarding SRT setup and usage, please feel free to contact our helpdesk so we could advise.

Related documentation

Nimble Streamer SRT feature set, Haivision blog: Reliable Low Latency Delivery with SRT+SLDP

SRT packet loss is fixed

Softvelum team is an active participant of SRT community and we follow up with all updates as well as contribute to the code base.

Recently the SRT library was updated with a commit which fixes packet loss for the case when SRT Sender is working in Listen mode.

This fix is on the master branch already, and it's on its way to the next SRT package release. Nimble Streamer team made changes to SRT Nimble Streamer package so our customers could make proper update and fix the problem for their streaming scenarios.

So if you use SRT Sender in Listen mode, we highly recommend you to upgrade SRT package.
This will fix the aforementioned problem and will improve your streaming experience.

If you have any questions, please feel free to contact our helpdesk so we could advise.

Related documentation

Nimble Streamer SRT feature set, SRT streaming setup,