Release Notes: Zixi Broadcaster Version 19
Zixi Platform V19 Release Notes
Version 19 (v19.2.47061) of the Zixi Broadcaster and Zixi Edge Compute is now a Generally Available (GA) release and includes the following new capabilities, bug fixes, and security updates.
Note: Not all features are available in Zixi Edge Compute.
V19.2.47061 Release Notes
Improvements
- Added #EXT-X-CUE-OUT-CONT tags to HLS adaptive output manifests on each segment during SCTE-35 ad breaks
- Added a "Reject unencrypted stream" option for Zixi Push and Pull inputs with decryption enabled, so unencrypted streams are dropped and reported as an error instead of being passed through unencrypted
- Removed the 60-segment limitation on HLS adaptive output playlists, enabling long sliding DVR windows
- Fixed an issue where a Zixi Pull input with slow or failing DNS resolution caused receive errors and packet loss on other inputs; DNS resolution is now asynchronous
Security
- Fixed an issue where the connection handshake was sent unencrypted when a Zixi Pull input or Push output reconnected after being redirected to another node; the encryption key exchange is now repeated on every such reconnect
- Hardened validation of SMPTE 2022-1 FEC and HEVC stream data, and of failover search window values supplied over the admin API, against malformed or malicious input
Bug Fixes
- Fixed an issue where the transcoder was stuck at 0 bitrate when the upstream source introduced additional PIDs, such as a failover to or from a slate
- Fixed an issue in Error Concealment where audio PES packets were removed indefinitely after a switch
- Fixed an issue where a spurious discontinuity tag was added to HLS output when a stream's timestamp was not yet initialized
- Fixed an issue where SCTE-35 packets were dropped on Remux-enabled HLS inputs; the remuxer now drains SCTE-35 packets when a timeline jump is detected
- Fixed an issue where a no-merge Failover Group reported continuity (CC) errors and packet loss that were not present on its component streams when the Broadcaster briefly stalled, for example on hosts with many offline Pull inputs (drafted - Jira text says TBD)
- Reduced the startup delay of the Broadcaster monitoring agent from 30-60 seconds to 15-25 seconds, shortening the gap in ZEN Master statistics after the agent restarts and reducing false "missing broadcaster data" alerts
- Fixed an issue where bonded input statistics read incorrectly after a stats reset
- Fixed an issue where interlaced field order was lost when transcoding to MPEG-2 with a resolution change, which could cause combing or judder downstream
- An MPEG-2 video profile set to interlaced output on a progressive source now fails the transcoded input with the error "Interlaced output from a progressive source is not supported", instead of silently ignoring the setting
- Fixed an issue where SCTE-35 marker reporting stopped permanently on an input after a corrupted PMT followed by a stream discontinuity or reconnect
- Fixed an issue where editing a component's priority in a no-merge Failover Group briefly dropped the group to a lower-priority input; priority edits are now applied seamlessly
- Fixed an issue where SRT inputs and outputs offered an SRT version that was not installed, leaving the stream offline with a "Failed to load library" error
- Fixed an issue where the Broadcaster did not exit on restart on older Linux distributions (CentOS/RHEL 7), preventing it from being relaunched automatically
- Fixed thumbnail extraction for H.264 streams with I-frames only (no IDR)
- Fixed an issue where transcoded audio went silent for the rest of the session when the AC-3 source changed its channel layout or sample rate mid-stream
- Fixed corrupted, sheared video when transcoding vertical (9:16) sources with an HTML overlay ("Dynamic Overlay URL"), and corrected the overlay size when cropping is applied to the transcoded input
- Fixed an issue where a SMPTE 2022-7 hitless Failover Group permanently lost one of its legs when the group's components were edited while both legs had no traffic, which left the group running unprotected while it still showed Connected
- Fixed an issue where several CPU transcodes with an HTML overlay on the same input degraded (low frame rate, bitrate below target, transcoder resets) even though the server had spare CPU
- Fixed an issue where a Zixi Push output stayed offline after a seamless redirect to another input made while the output was still connecting
API Updates
- Inputs (Zixi Push/Pull): new enforce_decryption (0/1, default 0) on add_stream.json / edit_stream.json; returned by get_stream_settings.json; rejecting inputs report error_code 35 "Encryption mismatch" in streams.json; config key <ENFORCEDECRYPTION>
- Adaptive Outputs: hls_chunk_count accepts values above 60
- Adaptive Outputs: scte_type accepts new values for CUE-OUT-CONT tag variants
- Adaptive Outputs (manifest): EXT-X-DATERANGE ad ranges now carry PLANNED-DURATION on CUE-OUT and END-DATE/DURATION on CUE-IN; #EXT-X-CUE-IN is emitted for auto-return breaks
- Error text: "Data is encrypted" renamed to "Encryption mismatch" on inputs and outputs
V19.1.46978 Release Notes
Improvements
- Updated SCTE-35 reporting to ZEN Master to report all SCTE PIDs, adding support for multiple SCTE PIDs per stream
- Added support for multiple SRT Listener inputs on the same port
- Added the capability to set the temporary directory used when executing a Broadcaster upgrade
- Improved performance of HLS inputs by updating pacing strategy, preventing 0 kbps bitrate drops
- Added "Time Left" value, measuring duration of data left in the buffer in milliseconds, to the Push and Pull stats graph and API
Bug Fixes
- Fixed an issue where the transcoder did not align GOP with the source when "Copy GOP from source" was selected (change in behavior since 18.9)
- Fixed an Error Concealment edge case where a video splice was not detected but an audio splice was, when returning to the original source
- Fixed an issue in Error Concealment where audio PES packets were removed indefinitely after a switch, causing audio corruption
- Fixed an issue where HLS input CUE-to-SCTE-35 conversion did not log splice direction (In/Out of Network) in ZEN Master after upgrading to v19
- Fixed a condition that caused Error Concealment to continuously report false detections of timeline jumps (false splice detection)
- Fixed an issue in Error Concealment where audio frames were dropped for 2 seconds during a switch when concatenating EC output to another EC input
- Fixed SRT Listener ZEN Target creation via the Broadcaster API to default "Verify Stream ID" to disabled on the corresponding SRT Listener input and output
- Fixed an issue where an injected clip played from a PCR-derived offset instead of from the start
- Fixed an issue where input statistics counters latched to zero after a stats reset on bonded streams
- Fixed Seamless Switch to wait for the current audio frame to complete before switching sources, so the last audio packet before a switch is no longer truncated
V19.0.46942 Release Notes
Security Update: SRT Library Vulnerabilities (July 2026)
Zixi has identified and addressed two critical vulnerabilities in the open-source libSRT library used by the Zixi Broadcaster product. Patched versions are available now.
Affected VulnerabilitiesCVESeverityDescriptionCVE-2026-55869CriticalHeap-based buffer overflow in KMREQ handling, enabling denial of serviceCVE-2026-55868CriticalEncryption state machine downgrade, enabling remote encryption bypass
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Impact
These vulnerabilities exist in all previously released versions of the SRT library and affect the SRT protocol integration within Zixi Broadcaster. The Zixi protocol and all other protocols supported by the Zixi platform are not affected.
Resolution
Within 24 hours of the official libSRT patch (v1.5.6) released on July 20, 2026, Zixi shipped updated Broadcaster builds that incorporate the fix:
- Zixi Broadcaster v19.0.46942 (re-release)
Required Action
- If you are running v19 of Zixi Broadcaster, download the latest v19 release from the customer portal, then upgrade via the Broadcaster UI.
These vulnerabilities affect all prior versions of the libSRT library and may impact other vendor products that incorporate SRT capabilities. The Zixi protocol and other protocols supported by the Zixi platform are unaffected by these vulnerabilities.
V19.0.46908 Release Notes
Time Addressable Media Store (TAMS)
Time Addressable Media Store. It enables broadcasters to store live streams as time-stamped segments, allowing precise access to any point in the content timeline. This capability supports real-time clipping, editing, compliance recording, and fast syndication without rendering or file transfers. Broadcaster v19 integrates with TAMS via APIs for segment upload and metadata handling, ensuring seamless workflows within the Zixi ecosystem. This architecture simplifies orchestration by using API-driven segment uploads and metadata, ensuring efficient and scalable workflows for live and near-live content.
SPTS Multiplexing
SPTS Multiplex (Single Program Transport Stream Multiplexing) allows combining selected PIDs from multiple SPTS sources into a single output stream. This feature enables flexible audio/video pairing and PID mapping without requiring external multiplexing hardware. Broadcaster v19 integrates this capability natively, with configuration via ZEN Master or API, supporting PID selection and remapping for precise stream control. By consolidating multiple feeds into one managed stream, SPTS Multiplex reduces infrastructure complexity and operational costs.
Zero Latency Frame Thinning
Zero Latency Frame Thinning is a feature in Broadcaster v19 that dynamically and gracefully reduces video frame rate under constrained network conditions without introducing additional latency or disrupting stream continuity. It selectively drops non-essential frames while preserving audio and key frames, ensuring uninterrupted delivery for critical live workflows. Broadcasters gain maximum resilience and cost efficiency by avoiding stream interruptions during extreme network fluctuations without deploying extra hardware or redundant paths when not feasible.
NETINT VPU Support
NETINT VPU (Video Processing Unit) integration in Broadcaster v19 enables ASIC-based hardware acceleration for high-density transcoding. These VPUs deliver ultra-efficient encoding for HEVC, H.264, supporting up to dozens of HD streams per card at a fraction of the power and cost of GPU or CPU-based solutions. Broadcaster v19 supports NETINT VPUs natively, allowing seamless deployment on-prem or in cloud environments. Broadcaster v19 with NETINT integration reduces CAPEX and OPEX significantly, lowering hardware footprint and energy consumption while scaling transcoding capacity for live workflows.
HLS Normalization
HLS Normalization in Broadcaster v19 ensures consistent, broadcast-grade transport streams from HLS inputs by repairing timeline irregularities (PCR, PTS, DTS), re-multiplexing segments, and cleaning SCTE-35 markers. This feature addresses issues introduced by upstream encoders or stitched HLS workflows, enabling predictable downstream delivery for contribution, distribution, and playout. This feature removes the need for costly preprocessing containers or third-party normalization tools, reducing infrastructure complexity and operational overhead.
Protocol Updates
Listed below are improvements and bug fixes to the various protocols supported by the Zixi Broadcaster.
- SRT: Added SRT library version selection for SRT sources and targets, enabling operators to select between SRT library versions
- HLS: Added #EXT-X-MEDIA tag for language metadata in HLS manifest output
- SCTE-35: Added support for SCTE insertion on Failover Groups
Transcoding Updates
- Note the updates on the v19 Transcoding datasheet.
- Updated Broadcaster to upscale CEF output beyond 1080 for up to 4K output
- Updated Transcoder to support Software HEVC decode and encode of 422 10-bit content with CEF for HTML Overlays
Additional Improvements
Additional improvements to the Zixi Broadcaster are listed below.
- Added the ability to individually enable logging on a per stream basis in the Broadcaster
- Updated API of HLS Input to return the number of Continuity Counters within a segment
- Added Frame Thinning with zero latency capability to HEVC streams
- Added support for JPEGXS metadata into the TR101 Analyzer.
- Added to TR101 Analyzer graphs of Frame Duration min/max/avg Elementary Stream values and deltas in the TR101 Dialog box
- Added ability to validate JPEG-XS metadata to TR101 Analyzer
- Optimized output flows to support higher bitrates without causing overflow errors
- Increased the maximum allowable bitrate to 1Gbps in UDP and ASI inputs
- Added support for Fastly Object Store as an HTTP Output and Recording Input target.
- Added HLS Tag Metadata Passthrough, enabling end-to-end pass-through of #EXT-X-ASSET and #EXT-X-PROGRAM-DATE-TIME manifest tags through the HLS-to-TS-to-HLS pipeline
- Improved Error Concealment to remove audio packets between splice point and first audio PES, preventing audio artifacts on stream switches
API Updates
Updates to API calls in the Zixi Broadcaster are listed below.
API Parameter Changes
- SCTE-35: Replaced keep_scte_null parameter with new support_scte_timeout timeout parameter for SCTE injection. Stream type is now auto-detected -- CBR inserts on null with timeout, VBR inserts immediately
- Failover Group: Added assume_identical parameter ([0/1]) to Failover Group API to bypass stream comparison for Hitless Merge, improving performance
New Feature APIs
- TAMS: Added vuuid (video flow UUID) and auuid (audio flow UUID) parameters to /zixi/set_adaptive_channel_with_streams.json for TAMS integration. OAuth Token URL, Client ID, Client Secret, Grant Type, and Scope are configurable via API
- SPTS Multiplex: New PID Interleaver source type with API parameters for primary_source, PID selection and remapping via comma-separated source/target PID pairs. Configurable via API, UI, and ZEN Master
- SRT: Added SRT library version selection parameter for SRT sources and targets, allowing operators to choose between SRT library versions
New API Response Fields
- Stats: Subtitle descriptors are now included in streams.json API response when present
V19.1.46978 Release Notes
Improvements
• Updated SCTE-35 reporting to ZEN Master to report all SCTE PIDs, adding support for multiple SCTE PIDs per stream
• Added support for multiple SRT Listener inputs on the same port
• Added the capability to set the temporary directory used when executing a Broadcaster upgrade
• Improved performance of HLS inputs by updating pacing strategy, preventing 0 kbps bitrate drops
• Added “Time Left” value, measuring duration of data left in the buffer in milliseconds, to the Push and Pull stats graph and API
V19.0 Release Notes
Time Addressable Media Store (TAMS)
Time Addressable Media Store. It enables broadcasters to store live streams as time-stamped segments, allowing precise access to any point in the content timeline. This capability supports real-time clipping, editing, compliance recording, and fast syndication without rendering or file transfers. Broadcaster v19 integrates with TAMS via APIs for segment upload and metadata handling, ensuring seamless workflows within the Zixi ecosystem. This architecture simplifies orchestration by using API-driven segment uploads and metadata, ensuring efficient and scalable workflows for live and near-live content.
SPTS Multiplexing
SPTS Multiplex (Single Program Transport Stream Multiplexing) allows combining selected PIDs from multiple SPTS sources into a single output stream. This feature enables flexible audio/video pairing and PID mapping without requiring external multiplexing hardware. Broadcaster v19 integrates this capability natively, with configuration via ZEN Master or API, supporting PID selection and remapping for precise stream control. By consolidating multiple feeds into one managed stream, SPTS Multiplex reduces infrastructure complexity and operational costs.
Zero Latency Frame Thinning
Zero Latency Frame Thinning is a feature in Broadcaster v19 that dynamically and gracefully reduces video frame rate under constrained network conditions without introducing additional latency or disrupting stream continuity. It selectively drops non-essential frames while preserving audio and key frames, ensuring uninterrupted delivery for critical live workflows. Broadcasters gain maximum resilience and cost efficiency by avoiding stream interruptions during extreme network fluctuations without deploying extra hardware or redundant paths when not feasible.
NETINT VPU Support
NETINT VPU (Video Processing Unit) integration in Broadcaster v19 enables ASIC-based hardware acceleration for high-density transcoding. These VPUs deliver ultra-efficient encoding for HEVC, H.264, supporting up to dozens of HD streams per card at a fraction of the power and cost of GPU or CPU-based solutions. Broadcaster v19 supports NETINT VPUs natively, allowing seamless deployment on-prem or in cloud environments. Broadcaster v19 with NETINT integration reduces CAPEX and OPEX significantly, lowering hardware footprint and energy consumption while scaling transcoding capacity for live workflows.
HLS Normalization
HLS Normalization in Broadcaster v19 ensures consistent, broadcast-grade transport streams from HLS inputs by repairing timeline irregularities (PCR, PTS, DTS), re-multiplexing segments, and cleaning SCTE-35 markers. This feature addresses issues introduced by upstream encoders or stitched HLS workflows, enabling predictable downstream delivery for contribution, distribution, and playout. This feature removes the need for costly preprocessing containers or third-party normalization tools, reducing infrastructure complexity and operational overhead.
Protocol Updates
Listed below are improvements and bug fixes to the various protocols supported by the Zixi Broadcaster.
- SRT: Added SRT library version selection for SRT sources and targets, enabling operators to select between SRT library versions.
- HLS: Added #EXT-X-MEDIA tag for language metadata in HLS manifest output.
- SCTE-35: Added support for SCTE insertion on Failover Groups.
Transcoding Updates
- Note the updates on the v19 Transcoding datasheet.
- Updated Broadcaster to upscale CEF output beyond 1080 for up to 4K output.
- Updated Transcoder to support Software HEVC decode and encode of 422 10-bit content with CEF for HTML Overlays.
Additional Improvements
Additional improvements to the Zixi Broadcaster are listed below.
- Added the ability to individually enable logging on a per stream basis in the Broadcaster.
- Updated API of HLS Input to return the number of Continuity Counters within a segment.
- Added Frame Thinning with zero latency capability to HEVC streams.
- Added support for JPEGXS metadata into the TR101 Analyzer.
- Added to TR101 Analyzer graphs of Frame Duration min/max/avg Elementary Stream values and deltas in the TR101 Dialog box.
- Added “Time Left” value, measuring duration of data left in the buffer in milliseconds, to the Push and Pull stats graph and API.
- Added ability to validate JPEG-XS metadata to TR101 Analyzer
- Optimized output flows to support higher bitrates without causing overflow errors.
- Increased the maximum allowable bitrate to 1Gbps in UDP and ASI inputs.
- Improved Error Concealment to remove audio packets between splice point and first audio PES, preventing audio artifacts on stream switches.
- Added support for Fastly Object Store as an HTTP Output and Recording Input target.
API Updates
Updates to API calls in the Zixi Broadcaster are listed below.
API Parameter Changes
- SCTE-35: Replaced 'keep_scte_null' parameter with new 'support_scte_timeout' timeout parameter for SCTE injection. Stream type is now auto-detected -- CBR inserts on null with timeout, VBR inserts immediately.
- Failover Group: Added 'assume_identical' parameter ([0/1]) to Failover Group API to bypass stream comparison for Hitless Merge, improving performance.
New Feature APIs
- TAMS: Added 'vuuid' (video flow UUID) and 'auuid' (audio flow UUID) parameters to /zixi/set_adaptive_channel_with_streams.json for TAMS integration. OAuth Token URL, Client ID, Client Secret, Grant Type, and Scope is configurable via API.
- SPTS Multiplex: New PID Interleaver source type with API parameters for 'primary_source', PID selection and remapping via comma-separated source/target PID pairs. Configurable via API, UI, and ZEN Master.
- SRT: Added SRT library version selection parameter for SRT sources and targets, allowing operators to choose between SRT library versions.
New API Response Fields
- Stats: Subtitle descriptors are now included in streams.json API response when present