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Comparison · Meetings
PJSIP vs SRS
A side-by-side editorial comparison of PJSIP and SRS — release velocity, themes, recent moves, and the top alternatives to consider.
PJSIP vs SRS: at a glance
What is PJSIP?
A mature SIP stack turns its attention to concurrency correctness and AI voice endpoints
PJSIP remains the reference open-source SIP and media stack for embedded and mobile softphones, shipping roughly one feature release a year. Version 2.17 pairs asynchronous client authentication with a documented real-time AI speech connectivity path, alongside ten separate deadlock fixes. The cadence is slow, but each drop carries a backward-incompatibility section integrators have to read before upgrading.
What is SRS?
SRS opens a 7.0 line built on a Go proxy tier, and drops features it no longer wants to carry.
SRS shipped the stable 6.0 line's first release on 12 August and, three hours later, the first development build of 7.0. The 6.0 line is now in pure maintenance — the r1 changelog is seven merges of DVR, WebRTC and edge fixes. Everything new is in 7.0-d0: RTSP playback, RTMPS, IPv6 across every protocol, HEVC in both directions between RTMP and WebRTC, and HLS fMP4 segments for HEVC and LL-HLS.
PJSIP vs SRS: editorial side-by-side
PJSIP
0.0MEETINGS
A mature SIP stack turns its attention to concurrency correctness and AI voice endpoints
◆ Current state
PJSIP remains the reference open-source SIP and media stack for embedded and mobile softphones, shipping roughly one feature release a year. Version 2.17 pairs asynchronous client authentication with a documented real-time AI speech connectivity path, alongside ten separate deadlock fixes. The cadence is slow, but each drop carries a backward-incompatibility section integrators have to read before upgrading.
◆ Where it's heading
The arc from 2.14 to 2.17 moves away from platform and codec breadth — IPv6 dual stack, a Metal renderer, Lyra, a Schannel TLS backend — and toward the harder problem of concurrency inside the media core: async conference bridge operations, then parallel bridging, then async authentication and systematic deadlock elimination. AI speech connectivity in 2.17 is the first indication the project treats voice agents, not only human callers, as a target workload. The growing list of API breaks suggests the maintainers will trade source compatibility for cleaner threading semantics.
◆ Prediction
Expect the next release to widen the AI speech path with more transport and codec options while continuing to convert blocking media-core calls to asynchronous ones.
SRS
6.3MEETINGS
SRS opens a 7.0 line built on a Go proxy tier, and drops features it no longer wants to carry.
◆ Current state
SRS shipped the stable 6.0 line's first release on 12 August and, three hours later, the first development build of 7.0. The 6.0 line is now in pure maintenance — the r1 changelog is seven merges of DVR, WebRTC and edge fixes. Everything new is in 7.0-d0: RTSP playback, RTMPS, IPv6 across every protocol, HEVC in both directions between RTMP and WebRTC, and HLS fMP4 segments for HEVC and LL-HLS.
◆ Where it's heading
The project is trading breadth of legacy surface for a narrower, better-covered core. 7.0-d0 removes the embedded GB28181 SIP server, multi-threading, Cygwin, and most configuration hot reload, while introducing a Go proxy server and origin-cluster architecture alongside the C++ media core. Protocol coverage keeps generalizing — each release makes a codec or an address family a property of the server rather than of one delivery path.
◆ Prediction
Expect the 7.0 line to run a long alpha and beta train the way 6.0 did, with the Go proxy and origin clustering carrying most of the remaining work and 6.0 continuing to receive backported fixes in parallel.
Alternatives to PJSIP and SRS
Other Meetings products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either PJSIP or SRS.
HOMER
Homer's storage churn pauses long enough to ship a catalog backup CLI.
mediasoup
mediasoup has moved off data-channel plumbing and into the media path — timing first, now layer selection.
Wowza
Wowza keeps arguing its case for detection inside the streaming pipeline
Vimeo
Vimeo ships another batched product post: six changes to embeds and the player
Switcher Studio
Switcher Studio's feed is a livestreaming how-to blog, not a changelog
Recent activity from PJSIP and SRS
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 6d agoSRSSRS 7.0-d0: Go proxy tier, RTSP playback, IPv6 across protocols ⚡
- 6d agoSRS6.0-r1: DVR, WebRTC and edge fixes on the stable line
- 3mo agoPJSIPPJSIP 2.17 adds async SIP auth and AI speech connectivity ⚡
- 8mo agoSRSSRS 6.0 goes stable with H.265 across RTMP, HLS, TS and SRT ⚡
- 8mo agoPJSIPPJSIP 2.16 brings real-time text and a parallel conference bridge
- 9mo agoSRS6.0-b3: use-after-free and HLS cleanup fixes
- 10mo agoSRS6.0-b2: configurable SRT stream IDs and a WHIP transcoding fix
- 11mo agoSRS6.0-b1: RTC crash fixes, Windows binary dropped
- 1y agoPJSIPPJSIP 2.15 adds Metal rendering, Schannel TLS and the Lyra codec
- 1y agoPJSIPPJSIP 2.15.1 fixes auth and async conference bridge bugs
- 2y agoPJSIPPJSIP 2.14.1 fixes an ICE deadlock and re-INVITE handling
- 2y agoPJSIPPJSIP 2.14 adds dual-stack IPv6 and mobile sample apps
Frequently asked questions
What is the difference between PJSIP and SRS?
They serve adjacent needs but don't currently overlap on shipped themes. SRS is currently shipping more aggressively (velocity 6.3 vs 0.0), with 1 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.
Is PJSIP better than SRS?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. SRS is currently shipping more aggressively (velocity 6.3 vs 0.0), with 1 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Meetings products to evaluate alongside.
What are the best alternatives to PJSIP?
Top PJSIP alternatives in Meetings are ranked by recent ship velocity. Browse the "PJSIP alternatives" section above for the current picks, or visit /alternatives/pjsip for the full list with editorial commentary on each.
What are the best alternatives to SRS?
Top SRS alternatives in Meetings are ranked by recent ship velocity. Browse the "SRS alternatives" section above for the current picks, or visit /alternatives/srs for the full list with editorial commentary on each.