Stream using vMix

This guide shows you how to stream live video from vMix to FastPix using RTMP or SRT protocols.

What you'll learn

• How to prepare your vMix setup for FastPix streaming
• How to configure RTMPS streaming to FastPix
• How to configure SRT streaming to FastPix
• How to monitor and troubleshoot your stream

Before you begin

Make sure you have:

• vMix installed - Download from vmix.com/software/download.aspx
• A FastPix account with API access
• An API access token with read/write permissions for FastPix Video
• Your video sources configured in vMix (cameras, video files, or other inputs)
• A stable internet connection with at least 2 Mbps upload speed

System recommendations

For optimal streaming performance with FastPix, see the vMix system requirements guide.

Recommended specifications for 1080p streaming:

Stream with FastPix

FastPix provides secure streaming with RTMP (RTMPS) and SRT protocols.

Create a FastPix live stream

Before streaming from vMix, create a live stream using FastPix. You can create a live stream in two ways:

Using the FastPix Dashboard - See the How to livestream guide
Using the FastPix API - See the Create a livestream API reference

Gather your stream details

After creating your live stream, save these values from the response. You will need them to configure vMix:

• streamKey - Your unique stream key for RTMP streaming
• srtSecret - Your passphrase for SRT streaming
• streamId - Your stream ID for SRT streaming
• playbackIds - IDs for viewing your stream

Note: Keep these credentials secure and don't share them publicly.

Stream with RTMPS

RTMPS provides secure streaming over RTMP.

1. In vMix, click Settings > Stream > gear icon.
2. Select Custom RTMP.
3. Set Protocol to RTMPS.
4. Enter the FMS URL: rtmps://live.fastpix.io:443/live
5. Enter your FastPix stream key.
6. Configure encoder settings:
   • Resolution: Match your FastPix maxResolution (for example, 1080p)
   • Bitrate: 4000 Kbps or as needed
   • Encoder: NVENC (recommended) or FFmpeg
7. Click OK.
8. Click Stream to start streaming.

Stream with SRT

SRT provides low-latency streaming with error correction, ideal for unreliable networks.

1. Click Settings (gear icon, top-right).
2. Select Outputs / NDI / SRT from the left sidebar.
3. Click the gear icon next to Output 1.
4. Configure these settings:
   • Resolution: Choose your output quality (for example, "H264 2mbps AAC 128kbps")
   • Audio Channels: Master
   • Alpha Channel: None
5. Check Enable SRT.
6. Set Type to Caller.
7. Enter the Hostname: live.fastpix.io
8. Enter the Port (for example, 778).
9. Set Latency to 200 milliseconds (increase if you experience network issues).
10. Enter your FastPix SRT secret in the Passphrase field.
11. Set Key Length to 32.
12. Enter your Stream ID from the FastPix API response.
13. Click OK on both dialog boxes.

Start or Stop SRT streaming

In the control bar of vMix, click External to start streaming (the button turns green whens streaming is active), and click it again to stop the stream.

View your stream

To view your stream, you can use the HLS playback URL or SRT playback URL. Refer to the HLS playback guide or the SRT playback guide for details.

When you stream with SRT on FastPix, you automatically get both SRT and HLS playback.

Troubleshoot common issues

No video input appears

Solution: Check that your camera or video source is connected and not being used by another app. Verify permissions in Windows Settings > Privacy > Camera.

Video is laggy

Solutions:

• Lower your output resolution
  • Go to Settings > Display tab
  • Change the Output Size to a lower resolution (for example, from 1080p to 720p), see vMix display settings and vMix streaming quality guides.
• Use a wired Ethernet connection instead of Wi-Fi
• Update your graphics card drivers
• Close unnecessary background apps

Audio is out of sync

Solution: Go to Settings > Audio and adjust the sync delay until audio matches video.

Streaming errors

Solutions:

• Verify your stream key and URL are correct, refer to using SRT to Live Stream
• Test your internet upload speed (need at least 2 Mbps)
• Check that your firewall allows outbound connections on ports 35000–35500
• Reduce your streaming bitrate
  • Click the gear icon next to the Stream button
  • Select a lower quality preset (for example, 720p instead of 1080p) or customize the bitrate to match your upload speed. See the vMix Streaming Quality guide

SRT stream won't connect

Solutions:

• Verify the hostname and port are correct
• Check firewall settings on both your computer and network
• Increase latency to 500–2000 milliseconds
  • Go to Settings > Outputs / NDI / SRT
  • Click the gear icon next to Output 1
  • Increase the Latency value, higher latency helps with difficult network conditions. See the vMix SRT configuration guide
• Confirm your passphrase matches your FastPix SRT secret

Advanced features

Monitor performance

Enable statistics to check for dropped frames or high CPU/GPU usage:

1. Go to Settings > Options.
2. Enable Statistics.
3. Monitor the stats overlay while streaming or recording.

Use keyboard shortcuts

Assign keyboard shortcuts for quick actions:

1. Go to Settings > Shortcuts.
2. Assign keys to transitions, recording, or other functions.
3. Click OK.

Enable advanced mode

To access all vMix features:

1. Go to Settings > Options.
2. Enable Advanced Mode.

Get help

vMix resources

For more information about vMix:

• Watch vMix training videos
• Read the complete user guide
• Visit the vMix support forums
• Contact vMix support

FastPix resources

For help with FastPix streaming:

• Read the complete FastPix documentation guides
• See the Live Streaming API reference
• Join the FastPix community discussions
• Contact FastPix support