Glossary

Definitions are alphabetised by term. Where an entry names an OpenAPI schema, field or enum value the citation is given so the reader can locate it in openapi.yaml.

A

ABR ladder. Adaptive-bitrate ladder. The ordered list of renditions a player can switch between as the network changes; produced by an Encoding group.

API base path. Every REST endpoint sits under /c21apiv2. The full URL is https://<host>/c21apiv2/….

API token. Opaque bearer string issued by POST /c21apiv2/security/tokens and returned exactly once at creation. Carried by the caller in the standard Authorization: Bearer <token> header. Tokens are owned by a user and inherit that user's role.

Asset. Media file managed by C21 Live Control and reusable across Live streams. The listAssets endpoint exposes three buckets: logos, files, clips.

Audit log. Authenticated-mutation history maintained by the server at the platform level. The audit surface varies per deployment; there is no unified Audit log UI tab in this release.

B

Bitrate. Data rate of a stream, in kilobits or megabits per second.

Broadcast. The act of distributing one Live stream to one or more Destinations.

C

CBCS. Common Encryption scheme — AES-128 in CBC mode with subsample skipping (cbcs). One of the two values of Publishing.drm.encryption_mode; default scheme for FairPlay outputs.

CENC. Common Encryption scheme — AES-128 in CTR mode (cenc). One of the two values of Publishing.drm.encryption_mode; used by Widevine and PlayReady.

CKC. Content Key Context. The license payload returned by a FairPlay license server in response to a player's SPC request.

Channel. Entity behind the Sources UI section. The Channel.type enum exposes 10 values: File, SDI, Stream, AES/EBU, RTMP-Push, UDP-R Cloud, SRT, SRT Cloud, NDI, Youtube Live. The customer-facing UI groups RTMP-Push, SRT Cloud and UDP-R Cloud under the single label "Stream – C21 Live Cloud".

Channel type. Value of the Channel.type enum (see above).

C21 Live Cloud. Managed cloud platform that provides cloud encoding capacity Live Control can dispatch to alongside on-prem encoders. Managed under Integrations → C21LiveCloud (addC21LiveCloudAccount, validateC21LiveCloudAccount).

C21 Live Cloud account. Persisted account that links Live Control to the C21 Live Cloud platform; backed by the C21LiveCloudAccount schema (client, client_id, password write-only, enabled).

Codec. Video or audio compression standard applied by an Encoding. Video values exposed by Encoding.settings_video.codec: h264, hevc, av1, mp4v, vp9, mpgv, copy. Audio values exposed by Encoding.settings_audio.codec: mp4a, aacp, opus, mp3, mpga, copy. The Encodings page documents the supported subset for new profiles; legacy values appear here because they remain in the schema.

D

DASH. Dynamic Adaptive Streaming over HTTP. One of the values of Publishing.type.

Destination. Entity behind the Destinations UI section. The Publishing.type enum exposes: HLS / TS, DASH, CMAF, RTMP, Enhanced RTMP, SRT, STREAM, SDIOUT, Record.

Destination group. Named bouquet of Destinations activated together. Fields: id, name, description, elements[] (Destination IDs).

Device. Entity behind the Devices UI section. One C21 Live Encoder instance paired with the control plane; fields include alias, location, ip_address, type, enabled, mountstatus, licensed.

Device group. Bundle of Devices acting as a single allocation pool. Fields: id, name, description, devices[]. All members must share the same type.

DRM. Digital Rights Management. Live Control attaches DRM to a Destination via its drm block; the platform supports the schemes Widevine, PlayReady and FairPlay (DrmProvider.supported_systems lists which schemes a provider can serve; Publishing.drm.systems picks which of those are advertised on the manifest) under one of two encryption modes (cenc, cbcs). The OpenAPI spec emits supported_systems in uppercase and Publishing.drm.systems in TitleCase — the UI and this glossary use TitleCase for readability.

DRM provider. Catalogue entry that holds the credentials for an upstream DRM service. Backed by the DrmProvider schema; provider_type is server-driven (today: AXINOM, EZDRM).

E

Encoder. Generic term for the encoder process running on a Device.

Encoding. Entity behind the Encodings UI section. Bundles video and audio settings. The schema exposes settings_video.codec, settings_audio.codec, bitrate, resolution, frame rate, HDR mode and codec-specific knobs.

Encoding group. Ordered set of Encodings bound to a Live stream as one multi-rate ladder. Fields: id, name, pipeline (read-only, derived from the first member), description, quality_order (asc / desc, drives the ABR ladder ordering), elements (IDs of the member Encodings).

Entrypoint. The point at which one stage of a running Live stream (the Channel, the Encoding or a Destination) feeds into or out of the broadcast. Surfaced on the on-air row as a coloured arrow whose colour reflects the runtime status.

F

Failover. Automatic substitution of a degraded source by the next member of its group. Logged on the Live stream's events.

FairPlay. Apple's DRM scheme; on Live Control it travels on CMAF (CBCS). One of the three values of DrmProvider.supported_systems.

FairPlay Streaming (FPS). Apple's HTTP-streaming DRM profile. Distinct from frames per second, which is also abbreviated fps.

FQDN. Fully Qualified Domain Name.

G

GOP. Group of Pictures — the keyframe-bounded segment of frames in a video stream.

Group. Generic term used by Encoding groups, Destination groups, Device groups and User groups. The exact meaning is disambiguated by the prefix.

H

HLS. HTTP Live Streaming. Available as both a Channel pull (under the Stream channel type) and a Destination origin (HLS / TS Destination type).

HEVC. High Efficiency Video Coding (H.265). One of the values of Encoding.settings_video.codec (hevc).

I

I-frame. Intra-coded frame; a self-contained keyframe.

Ingest. The act of receiving an input feed.

Idempotency key. Header (Idempotency-Key) that clients may attach to mutating requests; where the deployment supports it, retries do not duplicate side effects. Confirm with your platform team before building a client that relies on this behaviour.

K

Keyframe interval. Distance, in seconds or frames, between consecutive I-frames. Equivalent to GOP length for most practical purposes; exposed per-codec on the Encoding (for example Encoding.settings_video.h264.keyframe_interval).

L

License. Allowance installed on the instance. Managed via installLicense, getSystemLicenses, downloadSystemInfo.

License server. Remote service that issues content keys to a player on demand. Live Control integrates with the license servers of registered DRM providers.

Live Control. The product documented on this site.

Live stream. Configured, named broadcast that binds a Channel, an Encoding (or Encoding group) and a Destination (or Destination group) to a Device. LiveStream.status is an integer with 4 values: 0 stopped / idle, 1 starting (transient), 2 running, 3 error / failed; the UI condenses status > 0 to "Live" and status = 0 to "Off".

M

Manifest. HLS .m3u8 or DASH .mpd file describing the renditions and segments of a packaged output.

MCP. Model Context Protocol. The open protocol C21 Live Control's MCP server speaks to expose streaming operations to any MCP-compatible AI agent or automation.

MCP profile. Server-side profile that bounds the toolset an MCP client can call. Today: voice, readonly, operator, full. Selectable via the MCP server's TOOL_PROFILE environment variable at deployment time; the default when the variable is unset is full. NOC deployments should explicitly set TOOL_PROFILE=voice for a curated surface.

MediaCopilot. CIRES21's transcription, captioning and content-intelligence service. Live Control integrates with it as a post-stream export from a Recording.

Multicast. One-to-many IP delivery over UDP. Live Control supports multicast as an input (under the Stream channel type) and as an output (STREAM publishing type, MPEG-TS over UDP/RTP).

MPEG-TS. MPEG-2 Transport Stream container.

N

NDI. Network Device Interface. One of the values of Channel.type; the editor can discover sources automatically or accept a manually-typed stream name.

NVENC. NVIDIA's hardware video encoder, when the Device exposes a supported NVIDIA GPU.

Now-line. Vertical bar on the Scheduler that marks the current time.

O

On air. Live stream currently in status = 2. The On air view shows every such stream as a row.

Operator. One of the two user profiles (user_role = 2). Operators drive the day-to-day broadcast: the On air view, Live streams, the Scheduler, Recordings.

Overlay. Logo or graphic composited onto an encoded rendition. Applied at runtime via runtimeApplyLogo.

P

PlayReady. Microsoft's DRM scheme. One of the three values of DrmProvider.supported_systems.

R

Recording. Capture of a Live stream stored for VOD, produced by attaching a Record-type Destination to one of the Destination groups bound to the Live stream. Backed by the Recording schema; key fields: name, livestreamId, duration_seconds, size_bytes, started_at, ended_at (null while still being written), qualities, remotefolder.

Remote Folder. Network share (NFS or WebDAV) that Live Control uses to back up a Recording before retention deletes it. Backed by the RemoteFolder schema (name, host, folder, protocol, user, validation_status). System Administrator only. See Remote Folders.

Restart. Stop and re-start a Live stream. There is no public restart endpoint; the Operator stops the Live stream and starts it again.

Retry / backoff. Destination-side delivery loop. Each Destination has its own retry budget and exponential-backoff envelope.

S

SCTE-35. Society of Cable Telecommunications Engineers standard 35. Signalling format for digital programme insertion. The Live stream exposes a SCTE markers toggle that indicates whether SCTE-35 cue points are preserved.

Scheduler. UI section that hosts Schedules. The calendar view.

Schedule. Entity scheduled on the Scheduler. Binds a Live stream to a start time, end time, encoder and optional recurrence. The recurrence.type enum exposes 5 values: none, daily, weekly, workdays, weekend.

Segment. One HLS or DASH file in a packaged output. Default segment duration is 6 seconds; configurable per Destination.

Signed URL. URL whose query string carries a time-bound signature; used by Recording downloads.

Source. The Sources UI section catalogues Channels. See Channel.

SRT. Secure Reliable Transport. Appears in both Channel.type (SRT, SRT Cloud) and Publishing.type (SRT).

Stream (channel type). Channel type that pulls over HLS, RTMP, HTTP, RTP or UDP multicast (for example udp://@239.0.0.1:1234 or an HLS playlist URL).

Stream – C21 Live Cloud. Customer-facing UI label that groups the three cloud contribution variants of the Channel.type enum (RTMP-Push, UDP-R Cloud, SRT Cloud). Not an enum value in itself.

System Administrator. One of the two user profiles (user_role = 1). Full access — manages users, licenses, integrations, DRM providers and the system surface.

T

Target Folder. Credentials record (FTP, SFTP or S3) used by the Recordings Editor as a clip-export target. Backed by the TargetFolder schema; passwords and S3 secret keys are write-only. System Administrator only. See Target Folders.

Transport stream. Synonym for MPEG-TS in most contexts.

U

UDP. User Datagram Protocol. Transport beneath SRT, MPEG-TS UDP and RTP.

UDP-R. Cloud contribution variant of the Channel.type enum (UDP-R Cloud). Together with RTMP-Push and SRT Cloud makes up the family of Channels that terminate on the C21 Live Cloud platform.

Uptime. Elapsed time since the Live stream went on air.

User group. Membership collection. Fields: id, name, elements (member IDs). The schema does not expose description in this release; permissions are not attached here.

User profile. Permission template attached to a user. Carries role, api (whether the user may issue API tokens), admin, language, password_version.

V

VAAPI. Video Acceleration API.

Viewer. Concurrent client of an output endpoint.

VOD. Video on Demand. The packaged output produced from a finished Recording.

W

Widevine. Google's DRM scheme. One of the three values of DrmProvider.supported_systems.

Y

Youtube Live. One of the values of Channel.type. Pull from a Youtube Live channel; requires an active C21LiveYouTube license on the deployment.