Multi-Destination Streaming: Send One Stream to Multiple Platforms

Why Multi-Destination Streaming?

Your audience is not on one platform. They are split across YouTube, Twitch, Facebook, X, LinkedIn, and your own website. If you stream to only one, you leave viewers on the table. If you stream to all of them, you maximize reach from a single production effort.

The naive approach is to run multiple encoders or use the “restream” feature in tools like OBS. The problem: each additional output means another full encode cycle, multiplying your CPU load. Encode once for YouTube, again for Twitch, again for Facebook. With three encodes, you are using 3x the CPU for the same content. On a 1080p60 stream, that is the difference between a fanless mini PC and a noisy workstation.

The professional approach is multi-destination distribution at the gateway level: ingest the stream once, and fan it out to all destinations using zero-copy routing. The stream is decoded and encoded once (or not at all, in passthrough mode), and copies are sent to each platform with protocol and bitrate adaptation as needed.

This guide walks through how to set up multi-destination streaming efficiently, with specific configuration for major platforms.

Zero-Copy Distribution: How It Works

Traditional multi-destination streaming multiplies the work at each stage:

Camera → Encoder → [Encode for YouTube] → YouTube
                 → [Encode for Twitch]  → Twitch
                 → [Encode for Facebook] → Facebook

CPU load: 3x encoding

Zero-copy distribution changes the architecture:

Camera → Encoder → [Single ingest] → Gateway
                                       ├── Copy → YouTube  (RTMP)
                                       ├── Copy → Twitch   (RTMP)
                                       ├── Copy → Facebook (RTMP)
                                       ├── Copy → SRT out  (SRT)
                                       └── Copy → HLS      (HLS)

CPU load: 1x ingest + 0% per additional output

In Vajra Cast, this is called zero-copy distribution. Internally, the gateway uses multicast-style routing: the ingested stream data is written to shared memory once, and each output reads from that same buffer. Adding the 5th or 50th output uses zero additional CPU and zero additional memory bandwidth (beyond the socket I/O for sending the data).

This is not a theoretical optimization. It is the difference between needing a dedicated server per platform and running 10+ destinations on a Mac Mini.

Setting Up Multi-Destination Outputs

Step 1: Ingest Your Source

Configure a single ingest in your gateway. For maximum flexibility, use SRT:

SRT Listener on port 9000
Latency: 200ms (or appropriate for your network)
Encryption: AES-256

Point your encoder (OBS, vMix, Wirecast, hardware encoder) at this ingest as an SRT caller. Your stream is now in the gateway.

Alternatively, ingest via RTMP if your encoder does not support SRT. The gateway handles protocol conversion internally.

See the SRT setup guide for detailed ingest configuration.

Step 2: Create Output Destinations

For each platform, create a separate output. Each output is independent: it has its own protocol, URL, stream key, and optional transcoding settings.

Example configuration for a typical multi-platform setup:

Step 3: Enable All Outputs

In Vajra Cast, outputs can be enabled and disabled independently while the stream is live. This means you can:

• Start streaming to YouTube for a pre-show
• Enable Twitch when the main event begins
• Add Facebook mid-stream when the social team is ready
• Disable any output at any time without affecting the others

This is the hot management feature: no restarts, no interruptions, no downtime for other outputs when you modify one.

Platform-Specific Configuration

Each streaming platform has its own requirements and quirks. Here is what you need to know for the major platforms.

YouTube Live

Protocol: RTMP (also supports HLS ingest for premium accounts)

Ingest URL: rtmp://a.rtmp.youtube.com/live2

Stream key: Generated in YouTube Studio under “Go Live” > “Stream”

Recommended encoding:

Important notes:

• YouTube requires a keyframe interval of exactly 2 seconds for reliable ingest. Deviating from this causes delayed availability and buffering.
• YouTube transcodes everything server-side, so your stream will be available in multiple qualities regardless of what you send.
• For 4K streaming, your account needs to be verified and the feature enabled separately.
• YouTube supports persistent stream keys, so you can configure once and reuse.

Twitch

Protocol: RTMP

Ingest URL: Use the nearest Twitch ingest server. Check Twitch’s ingest server list or use rtmp://live.twitch.tv/app for automatic routing.

Stream key: Found in Creator Dashboard > Settings > Stream

Recommended encoding:

Important notes:

• Twitch has a 6,000 Kbps bitrate cap for most streamers. Partners and Affiliates may have higher limits.
• Twitch does not transcode for all streamers by default. Non-partners may only get their native quality, so avoid sending 1080p60 at 8 Mbps if your audience has bandwidth constraints.
• Twitch prefers 48 kHz audio sample rate (not 44.1 kHz).
• If you are using multi-destination and sending the same encode to both YouTube and Twitch, match the lower of the two requirements (e.g., 6,000 Kbps for Twitch compatibility).

Facebook Live

Protocol: RTMPS (RTMP over TLS, mandatory)

Ingest URL: rtmps://live-api-s.facebook.com:443/rtmp

Stream key: Generated per stream in Facebook Live Producer (one-time use by default)

Recommended encoding:

Important notes:

• Facebook requires RTMPS (TLS-encrypted RTMP). Unencrypted RTMP connections are rejected. Ensure your gateway supports RTMPS output.
• Facebook stream keys are single-use by default. For recurring events, set up a “Persistent Stream Key” in Live Producer.
• Facebook Live has a maximum resolution of 1080p and a recommended maximum bitrate of 6,000 Kbps.
• Facebook is stricter about keyframe interval than other platforms. Deviating from 2 seconds can cause ingest failures.

Custom SRT Destinations

For broadcast partners, CDN ingests, or your own infrastructure, SRT provides the most reliable and secure transport:

SRT Caller to srt://partner-server:9000
Latency: configured per-destination
Encryption: AES-256 with per-destination passphrase

Each SRT output in Vajra Cast can have its own latency, encryption, and bandwidth settings, independent of the ingest configuration.

HLS Output for Web Players

Vajra Cast includes a built-in HLS server for direct-to-viewer streaming. This eliminates the need for a separate media server:

HLS output:
  Segment duration: 4 seconds (standard) or 2 seconds (low-latency)
  Playlist depth: 3-5 segments
  Available at: http://your-server:port/hls/stream-name/index.m3u8

HLS output can coexist with all other outputs simultaneously. For a deeper dive on HLS configuration, see HLS Adaptive Streaming: Complete Setup Guide.

Quality Considerations for Multi-Destination

The Lowest Common Denominator Problem

When sending the same stream to multiple platforms without transcoding, you are limited by the most restrictive platform. If Twitch caps at 6,000 Kbps and YouTube accepts 9,000 Kbps, you either:

1. Send 6,000 Kbps to everyone: simple, but YouTube viewers get lower quality than possible
2. Transcode per destination: optimal quality everywhere, but costs CPU

For most productions, option 1 is the right trade-off. The quality difference between 6,000 and 9,000 Kbps at 1080p is visible but marginal, and the simplicity of a single encode is worth it.

For premium productions where per-platform quality optimization matters, Vajra Cast supports per-output transcoding with hardware acceleration (Intel QSV). You can send 1080p60 at 8,000 Kbps to YouTube and 1080p60 at 6,000 Kbps to Twitch, each transcoded from the same source with hardware encoding. On an Intel system with QSV, this costs a fraction of the CPU compared to software encoding.

Keyframe Alignment

All major platforms require a 2-second keyframe interval. If your source encoder produces keyframes at a different interval (say, 4 seconds), the gateway needs to either:

• Pass through and hope the platform tolerates it (unreliable)
• Transcode with the correct keyframe interval (reliable but costs CPU)

Best practice: Configure your source encoder to produce keyframes at 2-second intervals from the start. This ensures passthrough compatibility with all platforms and eliminates the need for gateway-level transcoding just for keyframe adjustment.

Frame Rate Considerations

YouTube and Twitch both benefit from 60fps content, especially for fast-motion (gaming, sports). Facebook caps at 30fps for most use cases. If you send 60fps to Facebook, it will either downsample or reject the stream depending on your account type.

For mixed 30fps and 60fps destinations, either:

• Encode at 30fps for universal compatibility (simpler)
• Encode at 60fps and let the 30fps platform downsample (usually works but not guaranteed)
• Use per-output transcoding to convert 60fps to 30fps for specific destinations

Monitoring Multi-Destination Outputs

When you are sending to 5+ destinations simultaneously, any one of them can fail independently. A YouTube stream key expiring, a Twitch server going down, or a network route changing can cause a single output to drop while all others continue working.

Per-Output Health Monitoring

Monitor each output independently:

• Connection state: Is the output connected? If RTMP, is the handshake complete?
• Bitrate: Is the output transmitting at the expected rate? A sudden drop suggests congestion or platform-side throttling.
• Error rate: For SRT outputs, watch packet loss. For RTMP outputs, watch for TCP retransmission delays.
• Duration: How long has this output been connected? Unexpected resets indicate instability.

Vajra Cast provides all of these metrics per output in the web dashboard and via the Prometheus /metrics endpoint.

Alerting

Set up alerts for:

• Any output disconnecting unexpectedly
• Output bitrate dropping below 50% of expected
• RTMP connection failing to re-establish within 30 seconds
• SRT packet loss exceeding 5% sustained

With Prometheus and Grafana, these alerts can trigger Slack messages, PagerDuty incidents, or webhook calls to your automation system.

Scaling Multi-Destination Distribution

How Many Outputs Can You Run?

With zero-copy distribution, the practical limit is network bandwidth, not CPU:

These are theoretical maximums. In practice, you want headroom for SRT retransmission overhead and burst traffic. Plan for 70% network utilization at peak.

CPU usage remains flat regardless of output count when using passthrough (no transcoding). With transcoding, each unique encode profile adds CPU load, but duplicating the same encode to multiple outputs remains zero-copy.

Multi-Server Distribution

For very large-scale distribution (100+ destinations or global reach), use a tiered architecture:

Source Encoder → Primary Gateway (Vajra Cast)
                    ├── SRT → Regional Gateway (US East)
                    │            ├── RTMP → YouTube
                    │            ├── RTMP → Twitch
                    │            └── HLS → CDN ingest
                    ├── SRT → Regional Gateway (Europe)
                    │            ├── RTMP → YouTube EU
                    │            └── SRT → Broadcast partner
                    └── SRT → Regional Gateway (Asia)
                                 └── RTMP → Regional platforms

SRT between gateways provides reliable, encrypted transport. Each regional gateway handles the “last mile” distribution to local platforms using the appropriate protocol.

Step-by-Step: Setting Up a 4-Platform Stream

Here is a concrete walkthrough for streaming to YouTube, Twitch, Facebook, and your own website simultaneously.

1. Configure the ingest:

Create an SRT listener on port 9000 with 200ms latency and AES-256 encryption.

2. Gather platform credentials:

• YouTube: Stream key from YouTube Studio
• Twitch: Stream key from Creator Dashboard
• Facebook: Generate a persistent stream key in Live Producer
• Own website: Note your Vajra Cast HLS endpoint URL

3. Create four outputs:

• Output 1: RTMP to rtmp://a.rtmp.youtube.com/live2/{key}
• Output 2: RTMP to rtmp://live.twitch.tv/app/{key}
• Output 3: RTMP to rtmps://live-api-s.facebook.com:443/rtmp/{key}
• Output 4: HLS with 4-second segments

4. Configure encoding (if source does not match platform requirements):

Set source encoder to H.264 High Profile, 1080p30, 6,000 Kbps, AAC 128 Kbps stereo, 2-second keyframe interval. This configuration is compatible with all four platforms in passthrough mode.

5. Start the ingest from your encoder.

6. Enable all four outputs. They start delivering simultaneously.

7. Monitor each output independently in the Vajra Cast dashboard.

Total CPU usage for 4 passthrough outputs: virtually the same as a single output.

Bottom Line

Multi-destination streaming is table stakes for any production that wants to maximize audience reach. The key is doing it efficiently: ingest once, distribute many, and use zero-copy routing to keep resource usage flat regardless of how many platforms you serve.

Configure your source encoder for the lowest common denominator across all platforms (2-second keyframes, 6,000 Kbps, H.264 High Profile), and let the gateway handle per-platform delivery. Monitor each output independently, because platform failures are independent events.

For the gateway setup, see the SRT Streaming Gateway guide. For protecting your source feed, see video failover best practices. For your web player output, see the HLS adaptive streaming guide.