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Encoder Setup (WHIP)

Flow uses WHIP (WebRTC Ingest) for low latency streaming. Flow does not transcode, so viewers receive the exact quality and bitrate your encoder sends. To go live, join your Flow Session as a moderator, open Streaming Controls, copy the WHIP URL and Stream Key, then configure your encoder using the settings below.

Getting Your WHIP URL and Key​

  • Join your Flow Session as a moderator and open Streaming Controls.
  • Copy the WHIP URL and Stream Key using the copy icons. You will see a “Copied” tooltip.
  • The WHIP URL defines the quality mode and bitrate limits of your session.
  • Only Flow Studio is available today. See Pricing for quality tier details.

These settings give the best results for low latency WHIP streaming:

Video (OBS Settings)

  • Output Mode: Advanced
  • Video Encoder: x264
  • Codec: H.264
  • Profile: High
  • Tune: Zero Latency
  • Keyframe interval: 1s or 2s
  • CPU Usage Preset: Fast or Very Fast
  • Rate control: CBR
  • Bitrate: 1,000–10,000 kbps (set according to your Flow tier)
  • Resolution: 1920x1080
  • Framerate: 24, 25, or 30 fps. Choose the framerate that matches your timeline.
  • Colour Format: NV12
  • Colour Space: Rec709
  • Colour Range: Limited

Audio

  • Codec: AAC
  • Bitrate: 128 kbps

Important

  • If you push above the bitrate allowed by the session preset, the stream may fail to start or drop frames. Flow does not modify or downconvert the stream.

Quality Tiers and Bitrate​

Flow Studio (current) targets ~10 Mbps for high-quality grading sessions. Future tiers (Flow Standard at ~6 Mbps, Flow Lite at ~3 Mbps) will offer options for different network conditions.

If viewers experience buffering or stutter, lower your bitrate before reducing resolution. See Pricing for details on quality tiers and credit costs.

Resolution Guidelines​

  • 1080p provides the best balance between clarity and performance.
  • If networks struggle, drop to 720p to stabilise playback more effectively than bitrate cuts alone.
  • Avoid resolutions above 1080p unless every participant has very strong internet.

Network Requirements​

Flow forwards your stream without transcoding, so your network must support the bitrate you send.

Host requirements

  • For a 6 Mbps stream, upload of at least 10 Mbps is recommended.
  • For a 10 Mbps stream, upload of at least 15 Mbps is recommended.
  • Wired Ethernet is ideal.
  • WiFi works but can cause jitter if the connection is weak.

Viewer requirements

  • Viewers must have download capacity equal to the host’s upload bitrate.
  • If multiple users share one network, each needs the full bitrate.

Colour Pipeline Notes​

Flow does not apply colour management, gamma shifts, or colour space conversion. The video your encoder sends is passed directly to the viewer via packet routing only (standard SFU behaviour).

Technical Details​

Encoder output: OBS outputs NV12 by default, which is YUV 4:2:0 Rec.709, typically limited range, 8-bit for H.264.

Flow SFU: Packet routing only; no colour or gamma transforms. The stream stays YUV 4:2:0 Rec.709.

Browser decoding: Browsers decode H.264 WebRTC streams as Y′CbCr 4:2:0, then convert to RGB for compositing. Higher chroma profiles (4:2:2 or 4:4:4) are not reliably supported for WebRTC playback.

Display pipeline: Browser RGB is colour-managed by macOS into the monitor profile (usually Display P3). Rec.709 SDR video on macOS is commonly rendered with an sRGB-ish / ~1.96–2.2 effective display gamma. Safari honours colour tags more aggressively than Chrome, which can create small gamma differences.

What This Means​

  • The host's calibrated grading monitor is always the ground truth.
  • MacBook displays may show slight differences in gamma or saturation.
  • These differences are normal for browser-based review tools and are not caused by Flow.

For the most consistent review, hosts should grade on a calibrated monitor and viewers should use displays that are profiled or familiar to their workflow.

Viewer issues​

  • Buffering or stutter: Lower the encoder bitrate. Prefer wired internet. Close other bandwidth-heavy apps.
  • Black video: Ensure your encoder is using H.264, High profile, 4:2:0 sampling.
  • Washed out colour: Viewer display may not be colour accurate. Confirm their display settings.

Host issues​

  • Audio missing: Enable AAC. In OBS, confirm audio is routed to the correct track.
  • Encoder fails to connect: Bitrate exceeds the session preset. Keyframe interval must be 1 or 2 seconds. Verify WHIP URL and Stream Key.

For more help, see the full Troubleshooting guide.