Streaming NDI vs SRT vs RTSP: video over IP a confronto

Streaming professionale: scegliere il protocollo

Video streaming professionale richiede protocollo adatto a use case: broadcast live, security camera, contribution, distribution. Tre protocolli dominanti: NDI (LAN/produzione), SRT (contribution Internet), RTSP (security/CCTV).

NDI (Network Device Interface)

Caratteristiche

• Sviluppato NewTek (now Vizrt)
• LAN streaming protocol
• Multi-stream simultaneous
• Discovery automatic
• Bidirectional (camera control via PTZ)

NDI versions

• NDI HX: H.264 compresso, 8-25 Mbps
• NDI HX2: H.265, 1080p < 5 Mbps
• NDI HX3: AV1 codec, ottimizzato banda
• NDI 5: full bandwidth fino 250 Mbps, 4K UHD
• NDI 6: aggiunto features SDK

Use case NDI

• Live production broadcast
• Multi-camera church streaming
• Esports production
• Corporate events
• OBS Studio integration

Vantaggi NDI

• Plug-and-play zero config
• 1Gb network sufficiente HX
• Discovery automatic
• Free SDK + tools
• OBS Studio integrazione nativa

Svantaggi NDI

• Latency 80-200ms HX
• Compressione visibile HX
• Solo LAN (no Internet routing)
• Bandwidth alto NDI 5 full

SRT (Secure Reliable Transport)

Caratteristiche

• Sviluppato Haivision, ora open source
• Protocollo trasporto su Internet/WAN
• UDP-based con error correction
• AES-128/256 encryption
• NAT traversal

Funzionamento

• FEC (Forward Error Correction)
• ARQ (Automatic Repeat Request) opzionale
• Latency configurabile (250-2000ms)
• Bitrate adaptive

Use case SRT

• Contribution feed remoto a studio
• Live news from field
• OB van to broadcaster
• Sport events
• Backup link RTMP

Vantaggi SRT

• Affidabile su Internet con packet loss
• Crittografia integrata
• Open source standard
• Adottato da Adobe, Comcast, NEP, Disney
• Best-in-class per contribution

Svantaggi SRT

• Latency higher (250ms+)
• Setup configurazione richiesto
• Encoder/decoder dedicati
• Non per LAN low-latency

RTSP (Real Time Streaming Protocol)

Caratteristiche

• RFC 2326 (1998)
• Standard IP camera/CCTV
• TCP control + UDP/RTP media
• Streaming H.264/H.265

Use case RTSP

• IP camera security
• NVR ingest
• VMS integration
• Frigate NVR / Home Assistant
• Legacy streaming

Vantaggi RTSP

• Standard universal CCTV
• Latency bassa LAN (100-500ms)
• Multipli ricevitori
• Implementato qualsiasi camera IP

Svantaggi RTSP

• Non sicuro nativo
• Internet streaming difficile (NAT, firewall)
• Affidabilità dipende rete
• Non per WAN streaming

RTMP (Real-Time Messaging Protocol)

Caratteristiche

• Adobe Flash legacy
• TCP-based
• Standard YouTube/Facebook live ingest
• Latency 2-5 sec

Use case RTMP

• YouTube/Twitch live streaming
• Facebook Live
• Periscope (legacy)
• OBS Studio default

Vantaggi RTMP

• Universale per piattaforme
• Setup semplice
• Stable su Internet

Svantaggi RTMP

• Latency alta
• TCP issues con perdita pacchetti
• Adobe abbandono Flash → declino
• Sostituito da RTMPS+SRT moderni

WebRTC

Caratteristiche

• Peer-to-peer browser-based
• UDP latency < 1 sec
• Encryption obbligatoria
• NAT traversal STUN/TURN

Use case

• Video conferencing (Zoom, Teams)
• Browser streaming live
• Real-time interaction esports
• Telehealth

Confronto sintetico

Protocollo	Latency	Use case	Network
NDI HX	80-200ms	LAN production	1Gb
NDI 5	30-80ms	LAN broadcast	10Gb
SRT	250-2000ms	Internet contribution	WAN
RTSP	100-500ms	CCTV/security	LAN
RTMP	2-5s	YouTube/Twitch	WAN
WebRTC	<1s	VC/interactive	WAN
SDVoE	<16ms	Critical install	10Gb LAN

Workflow tipici

Live church streaming

• Camere PTZ NDI → OBS Studio → RTMP → YouTube
• Latency totale 2-5 sec audience
• NDI in LAN garantisce production fluida

Sport contribution

• OB van → SRT encoder → Internet → SRT decoder broadcaster
• Latency 1-2 sec
• Backup ridondato

Security CCTV

• IP camera → RTSP → NVR/Frigate
• Latency 100-300ms
• Storage local + cloud highlights

Esports production

• Capture cards → NDI 5 → switcher → RTMP/SRT → Twitch
• Multi-view production
• WebRTC per audience interaction

Hardware/software

Encoder

• OBS Studio (free)
• Wirecast Pro
• vMix
• Hardware: AJA Helo Plus, NewTek TriCaster, Blackmagic ATEM Constellation
• Sienna NDI tools

Decoder

• NDI Studio Monitor
• VLC media player (RTSP, RTMP)
• OBS Studio (input multipli)
• FFmpeg

Integrazione domotica

Streaming NDI/RTSP integrabile in Home Assistant per scenari “monitoring”: telecamere RTSP via Frigate, NDI feed in dashboard. Per chiese parrocchiali, scene “messa” attivano camere NDI + recording + RTMP a YouTube simultaneamente.

FAQ

NDI o SRT?

NDI per LAN production. SRT per contribution Internet. Differenti use case.

RTSP sicuro?

Non nativo. RTSPS (TLS) emerge ma supporto limitato. Best practice: VPN, isolated VLAN.

Quanti stream NDI in 1Gb?

NDI HX 1080p: 10-15 stream. NDI 5 full: 1-2 stream. 10Gb necessario per multi-camera 4K NDI 5.

Latency YouTube?

RTMP standard 5-30 sec. YouTube Low Latency 2-5 sec. Ultra Low Latency 1-2 sec.

Posso convertire RTSP a NDI?

Sì, gateway software (NDI Tools, Sienna ND-Bridge). Util per security camera in NDI workflow.

SRT supporta 4K?

Sì, bandwidth dipendente. 4K H.265 SRT: 15-25 Mbps tipico.

WebRTC sostituisce RTMP?

Per low-latency interactive sì. Per broadcast tradizionale RTMP/HLS standard ancora.