The Real-Time Messaging Protocol has been a workhorse of live streaming infrastructure for decades, but its original specification was never designed to carry modern audio and video codecs. The industry has long had to work around this limitation until Veovera Software Organization stepped in.
The Enhanced RTMP specification
Veovera’s Enhanced RTMP specification is an open, community-driven effort to extend RTMP beyond its original boundaries. Rather than abandoning RTMP in favor of entirely different ingest protocols, Enhanced RTMP expands what the protocol can carry while preserving full backward compatibility with existing infrastructure.
The first wave of Enhanced RTMP adoption brought HEVC/H.265 and AV1 video codec support to the protocol, both of which Nimble Streamer already supports. The specification has since continued to evolve, adding definitions for a broader set of audio and video codecs that had no place in legacy RTMP.
What’s added in Nimble Streamer
Nimble Streamer now implements the latest Enhanced RTMP specification additions, introducing support for the following codecs over RTMP:
Video:
- VP8: Google’s open, royalty-free video codec, widely used in WebRTC contexts
- VP9: VP8’s successor, offering significantly improved compression efficiency at equivalent quality
Audio:
- Opus: a highly versatile, low-latency audio dominant codec in WebRTC pipelines
- FLAC: Free Lossless Audio Codec; lossless compression for use cases where audio fidelity is non-negotiable
- AC3 (Dolby Digital): the broadcast-industry-standard surround audio codec, used extensively in cable, satellite, and OTT distribution
- EAC3 (Dolby Digital Plus / E-AC-3): the enhanced successor to AC3, supporting higher channel counts and bitrates, and required for many streaming platform delivery specifications
All RTMP modes covered
These codecs are not limited to a single operational scenario. Nimble Streamer’s Enhanced RTMP codec support works across all four RTMP modes the server operates in:
- Receive: Nimble Streamer accepts incoming published RTMP streams carrying any of these codecs from encoders, broadcast software, or upstream servers.
- Pull: Nimble can actively pull RTMP streams from remote origins, including those that use Enhanced RTMP codec signaling. This also includes fallback streams and pull by request.
- Republish: Streams received or pulled can be forwarded to downstream RTMP destinations – other media servers, CDN ingest points, or platform endpoints, with codec passthrough intact.
- Playback: Nimble can serve RTMP playback output to any connected player or downstream software that supports Enhanced RTMP.
This end-to-end coverage means you can build entire pipeline segments – from ingest through distribution – using these codecs without any forced transcoding or format conversion steps. All these pipelines may now deliver these aforementioned codecs.
The full picture of what Nimble Streamer supports over RTMP, including transmuxing to HLS and MPEG-DASH, SRT and MPEG-TS output, DVR recording, republishing rules, publish control, and ABR stream assembly, is documented on the Nimble Streamer RTMP capabilities page.
Why this matters for your infrastructure
Bridging WebRTC and RTMP worlds
VP8, VP9, and Opus are the native codecs of WebRTC. Browser-based capture and conferencing tools generate these codecs natively, and historically they could not be injected into an RTMP pipeline without a transcoding step. With E-RTMP support in Nimble Streamer, WebRTC-originated content can flow directly into your RTMP ingest and vice versa, within distribution infrastructure, eliminating unnecessary CPU overhead and latency introduced by transcoding.
Lossless audio ingest
FLAC support opens up professional audio workflows where source quality must be preserved at every stage before final distribution encoding. Also, SLDP protocol will support FLAC for browser playback. So studios, radio broadcasters, and archiving pipelines can now use RTMP as a transport without any lossy intermediate step on the audio track.
Broadcast-grade surround audio
AC3 and EAC3 are not fringe formats, they are the codecs that power multichannel audio in broadcast television, cable distribution, and major streaming platforms. Operators who deal with 5.1 or 7.1 surround content no longer need to transcode or re-wrap audio before RTMP transport. AC3 and EAC3 streams can now be received, forwarded, or republished over RTMP natively.
Reduced transcoding complexity
One of the operational costs of a media server deployment is transcoding – converting between codec formats because a protocol or downstream system doesn’t understand what came in. Every transcoding step adds latency, CPU load, and a potential quality degradation point. By expanding what Nimble can carry natively across all RTMP modes, the E-RTMP implementation directly reduces the scenarios where transcoding is forced rather than chosen.
Get started
If you are already running Nimble Streamer, update to the latest version to get Enhanced RTMP codec support. If you are evaluating Nimble Streamer for your infrastructure, install it now, with a free trial of WMSPanel, giving you full access to the management interface and monitoring from the start.