SRT 2020 Vision Webinar Highlights
Did you tune into the SRT 2020 Vision webinar last week?
Hosted by the SRT Alliance, Haivision, and Microsoft, the webinar marked the kickoff for the SRT Plugfest, an event focused on giving the members of the SRT community the opportunity to test interoperability and compatibility between different technologies using the SRT protocol. During the webinar, Haivision’s SRT expert, Marc Cymontkowski gave viewers an update on the vision for SRT in 2020. In case you missed it, you can watch the webinar or read some of the highlights below.
SRT Support Grows Stronger
From the steadfast commitment of SRT’s original developers, Haivision, to ensure that the SRT protocol thrives, to the open-source ecosystem and the 350+ members of the SRT Alliance, support for SRT continues to gather momentum. This strength is underpinned further by the recent SRT IETF initiative, in partnership with SKT, which aims to ensure that information and knowledge about the protocol are appropriately documented and shared with the community.
SRT 1.5 is Coming Soon
Later this year, you can expect to see SRT 1.5. The most exciting development in this release is Connection Bonding, which has previously been referred to as socket groups. There are three different modes that are being implemented that are currently being tested on GitHub: broadcast, main/backup, and balancing mode. To take a deeper dive into this new feature and the benefits of each mode, watch the webinar recording for all the details. In addition,1.5 will also include support for C++11. In an early preview into the roadmap, Marc also highlights new features that will be included in future SRT releases such as bidirectional metadata exchange, improved bandwidth estimation, and multicast support.
SRT and RTP: What You Need to Know
To clear up any lingering confusion on the subject, Marc reiterates that SRT is fully interoperable with existing RTP workflows. SRT allows you to transmit RTP payload reliably and securely, so you can absolutely leverage SRT while maintaining your existing RTP-based broadcast infrastructure. To read more about this topic, check out Marc’s blog post.
Saving the Sweetest News Until Last: DSRT
Last, but not least, Marc announced the latest SRT initiative, known as DSRT (dessert), short for DASH over SRT which is focused on segmented workflows over SRT (including HLS and CMAF). SRT exists to solve contribution workflows, typically carrying MPEG2 transport streams for compatibility with existing broadcast infrastructure. However, this requires transcoding and repackaging the stream before delivery to many clients over a content delivery network, since modern CDNs are built to scale by relying on file-based distribution workflows. MPEG-DASH and HLS (HTTP Live Streaming) are the most popular streaming formats, which can be consumed directly by web browsers. Both streaming protocols now support a common media format called CMAF.
In cases where transcoding and repackaging of the content aren’t desired, a source encoder can directly send CMAF over DASH or HLS to the CDN as contribution format, so the CDN can deliver the content to the clients without further processing. Both protocols are utilizing TCP based HTTP for the transfer, which is not capable of utilizing a network connection to its fullest extent. When sending the CMAF segments over SRT for contribution, those network limitations are avoided and CDNs are natively able to distribute them without further processing, avoiding additional latency and cost introduced by video processing.
This initiative is just starting, so look out for more details soon.