> ## Documentation Index
> Fetch the complete documentation index at: https://docs.dfine.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Encoder settings

> The encoder settings Streaming Classic expects, and where to set them on OBS, Kiloview E1, Blackmagic WebPresenter and AJA HELO.

Every encoder that streams to Streaming Classic needs the same handful of settings. Set them once on your encoder, then enter your [ingest URL](/en/streaming-classic/ingest-server-url) and [stream key](/en/streaming-classic/stream-key).

| Setting | Value |
| - | - |
| Video codec | H.264 |
| H.264 profile | **Main** or **Constrained Baseline**, never High |
| Keyframe interval | **1 second**: GOP size equals the frame rate, for example 25 at 25 fps |
| Rate control | CBR (constant bitrate) |
| Video bitrate | 5 Mbit/s for 1080p is a good start. Stay within your plan |
| Resolution and frame rate | The same as your source |
| Audio | AAC, 128 kbit/s, 48 kHz |
| Protocol | RTMPS |

<Note>
  The keyframe interval decides how fast a viewer sees the first frame. With a keyframe only every 2 seconds, viewers waited 0.7 to 2.4 seconds longer for the picture in our measurements. A keyframe every second keeps the start short.
</Note>

<Warning>
  The player only plays Main or Constrained Baseline. With the High profile, viewers see **"Please set your encoder to the Main or Constrained Baseline H.264 profile, then restart the stream."**
</Warning>

## Settings per encoder

<Columns cols={2}>
  <Card title="OBS" icon="sliders" href="/en/streaming-classic/obs/encoder-settings">
    Every value in the OBS output settings, step by step.
  </Card>

  <Card title="Kiloview E1" icon="box" href="/en/streaming-classic/workflows/kiloview-e1-sdi">
    The H.264 main stream parameters in the web interface.
  </Card>

  <Card title="Blackmagic WebPresenter and ATEM" icon="cpu" href="/en/streaming-classic/workflows/blackmagic-webpresenter-atem">
    A streaming XML with bitrate profiles to load into the setup utility.
  </Card>
</Columns>

## AJA HELO

In the HELO web interface, create a streaming profile with the values from the table above: H.264 with the Main profile, a keyframe every second, CBR at your bitrate and AAC audio at 48 kHz. Set the stream to RTMPS and enter your ingest URL and your stream key in its stream settings.


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