Tutorial · vMix live production
vMix tutorial every streaming field filled in
This vMix tutorial puts your broadcast on your Primcast channel in a few minutes: you set the destination to Custom RTMP Server, paste the server into URL and the stream name into Stream Key, and add your login under Advanced.
After that come the quality settings that keep playback smooth for your viewers, an SRT option for shaky connections, and a quick way to check you are really live.
- Destination
- Custom RTMP Server
- URL
- rtmp://HOST:1935/APP
- Stream Key
- livestream
- Application
- FFMPEG
- Keyframe Frequency
- 2
- Advanced · Username
- USERNAME
- Advanced · Password
- PASSWORD
The values in capitals and the stream name come from your Primcast panel. Field names as vMix 29 labels them.
Before you start: copy four values from your panel
vMix needs to know where to send the broadcast and how to sign in. All of it is waiting for you in one place, so there is nothing to guess.
Find your encoder settings
Sign in, open your video account and go to the Live streaming card. Under Encoder settings you will see:
- Server
- Your address and application name, shaped like
rtmp://HOST:1935/APP. - Stream name
- Most channels use
livestream. - Username
- The login for publishing a stream.
- Password
- Hidden until you click Show. New password makes a fresh one.
Copy them, don't retype them
Each value has its own copy button, so use it. The application name in particular is yours alone. Plenty of general guides use live, and typing that out of habit gets the connection turned away.
The username and password are for publishing this stream only. They are not the email and password you use to sign in to Primcast.
Running your own dedicated streaming server? Then these values live in that server's own configuration. Ask us in chat and we will point you to them.
Does your card also show a Nearest server? Use that address as the server instead. vMix then connects to our closest location (New York, Miami, San Francisco, Amsterdam or Bucharest) and your stream travels the rest of the way over our network. Stream name, username and password stay exactly as they are.
vMix RTMP setup: URL, Stream Key and login
Open the streaming settings in vMix and follow these in order. The field names are the ones vMix uses in its own help for version 29.
- Set Destination to Custom RTMP Server.
- In URL, paste the server from your panel. It ends with the application name and goes no further.
- In Stream Key, paste the stream name on its own. Some vMix versions call this field Stream Name.
- Leave Application on FFMPEG, which vMix recommends.
- Open Advanced and fill in Username and Password with the publishing login from your panel.
This works
URL rtmp://HOST:1935/APP Stream Key livestream
This gets refused
URL rtmp://HOST:1935/APP/livestream Stream Key (empty)
vMix gives no clear error for this. The connection simply fails, which is why it is worth checking first.
No Username and Password fields in your version of vMix? You can put the login in the URL instead: rtmp://USERNAME:PASSWORD@HOST:1935/APP. If your password has an @, a colon or a slash in it, click New password in the panel for one without them.
vMix quality settings your viewers will notice
Pick a quality preset, then click the cog beside it to fine-tune. Two settings decide whether people watching see a smooth picture or a spinning wheel: keyframes and bitrate.
Keyframe Frequency: 2
We cut your broadcast into short playback segments, and each cut lands on a keyframe. Two seconds between keyframes gives even segments. Raise it and viewers start to stall, while vMix keeps telling you all is well.
Good news: 2 is vMix's own default. If somebody changed it, or a preset did, set it back.
The rest of the profile
- Format
- H264, which every player and browser can show.
- Profile
- Main for better quality, Baseline if your computer is struggling.
- Preset
- veryfast, as vMix suggests.
- Audio
- AAC at 128 kbps.
Bitrate: match it to your upload
Add video and audio together, and keep that total to about two thirds of the upload speed you measured. So if a speed test shows 6 Mbps, send around 4 at most.
| Encode Size | Video Bit Rate | Audio Bit Rate | Upload you need |
|---|---|---|---|
| 1920x1080, 30 fps | 4500 kbps | 128 kbps | 7 Mbps |
| 1280x720, 30 fps | 2500 kbps | 128 kbps | 4 Mbps |
| 854x480, 30 fps | 1200 kbps | 96 kbps | 2 Mbps |
The paid live video plans take up to 5 Mbps in, so the 1080p row fits. Run the speed test on the computer running vMix, at the time of day you plan to go live, and try it more than once. Use a network cable rather than Wi-Fi on that computer if you can.
Fans spinning hard or dropped frames in vMix? Tick Use Hardware Encoder if you have an NVIDIA GPU. The GPU then does the encoding and leaves the processor free for your scenes, titles and cameras.
Go live and make sure it arrived
- Save the settings and press Stream in vMix.
- Open the Live streaming card in your Primcast panel. Within about 15 seconds it should show you as live, along with what vMix is sending.
- Copy the playback link from the same card and open it in VLC or any HLS player. Give it a few seconds: nothing plays until the first segments exist.
Your channel's own link has this shape. Where your plan includes a CDN link, the card shows that one beside it, and either works. The card also has an embed code for your own website.
http://HOST:1935/APP/livestream/playlist.m3u8
| What you see | What to do |
|---|---|
| vMix can't connect at all | Check that URL stops at the application name and that Stream Key holds only the stream name. Then compare the host and application name with your panel, letter by letter. |
| The URL and key are right, and it still will not connect | Check the username and password next. Copy both again from the panel, or make a new password and paste that in. |
| Nothing connects from one particular network | Some office, school and hotel networks block port 1935. Try another connection, or send over SRT (step 05). |
| vMix looks fine but viewers buffer | Set Keyframe Frequency back to 2, then lower the bitrate by one row. Your upload may be slower at that hour than you expect. |
| It drops a few times a day | You are close to the top of your upload. Go down a row in the table, or move the computer onto a cable. |
vMix SRT: for long or shaky connections
SRT holds a stream together over links where RTMP tends to stall: venue Wi-Fi, a mobile uplink, or a feed coming from another continent. It comes with the Pro and Platinum plans of our video CDN, and your Live streaming card then shows an SRT ingest section with your own address and passphrase.
In vMix, SRT is set up on an output rather than in the streaming settings. Open Settings, then Outputs, click the cog next to the output you want to send, tick Enable SRT and fill in the values on the right.
A stream sent over SRT plays under its own name, so use the link the panel shows under Plays at while you broadcast this way.
- Type
- Caller
- Hostname
- HOST
- Port
- PORT
- Latency
- 1000
- Passphrase
- PASSPHRASE
- Key Length
- 16
- Stream ID
- leave empty
Host and port come from the Address line of your SRT ingest section.
Dropouts, reconnecting and more destinations
There's no auto-reconnect switch to find
vMix reconnects by itself after a dropout. There is no box to tick, so if you have been told to switch it on, that advice was meant for another encoder.
Reconnecting only decides how quickly you come back. Your viewers still lose those seconds, so if breaks keep happening, look at your bitrate and connection in step 03.
Stream once, show up everywhere
vMix can send to three destinations at once, but each one uses your upload again. Send one stream to Primcast and add YouTube, Facebook, Twitch or any RTMP server under Restream in your Live streaming card instead, up to five destinations. Your upload carries one stream and our network does the rest.
vMix streaming questions
How do I stream from vMix to a custom RTMP server?
In the streaming settings, choose Custom RTMP Server as the destination. Paste the server address with the application name into URL, the stream name into Stream Key, and your publishing username and password under Advanced. Save and press Stream.
What is my vMix stream key?
For a Primcast channel it is the stream name shown under Encoder settings on your Live streaming card, which is livestream for most channels. It goes in the Stream Key field by itself, never on the end of the URL.
Where is auto-reconnect in vMix?
There isn't a setting for it. vMix reconnects on its own after a dropout, so there is nothing to switch on. If breaks keep coming back, lower your bitrate or put the computer on a network cable.
Is the application name always "live"?
No. Your application name belongs to your channel and is part of the server address in your panel. Copy it from there. A guessed name gets the connection refused.
What keyframe interval should I use in vMix?
Set Keyframe Frequency to 2 seconds, which is also the vMix default. Playback segments are cut on keyframes, so a longer gap turns into stalls for your viewers even when vMix shows no problem.
What bitrate should I stream at from vMix?
Around 2500 kbps for 720p or 4500 kbps for 1080p at 30 frames per second, plus 128 kbps of audio. Keep the total to about two thirds of the upload speed you measured on the computer running vMix.
Can vMix stream to Primcast over SRT?
Yes, on the Pro and Platinum video CDN plans. Enable SRT on a vMix output in Caller mode and enter the host, port and passphrase from the SRT ingest section of your panel, with latency 1000 and key length 16.
Can I stream to YouTube and Facebook at the same time?
Yes. Send one stream from vMix to Primcast and add the other platforms under Restream in your Live streaming card, up to five destinations. That way your upload only carries one copy.
Using another encoder too?
Your channel takes the same four values from any RTMP encoder. Only the field names change.
Need a channel for your vMix show?
Open a video channel, copy your values into vMix and watch your own stream play. Stuck on a field? Our chat answers in seconds and can look at your channel while you wait, and a person joins whenever you ask.