# `Emerge.Config.PrimeFrames`
[🔗](https://github.com/emerge-elixir/emerge/blob/v0.5.1/lib/emerge/config/prime_frames.ex#L1)

Linux DMA-BUF frames for a headless GPU renderer. Set this record as
`Emerge.Config.Headless.frames`; CPU raster does not support this output.

```elixir
%Emerge.Config{
  output: %Emerge.Config.Headless{
    target: self(),
    frames: %Emerge.Config.PrimeFrames{device: "/dev/dri/renderD128"}
  },
  renderer: %Emerge.Config.Renderer{api: :opengl},
  assets: %Emerge.Config.Assets{otp_app: :my_app}
}
```

## Fields

- `device` — absolute path to the export DRM device. Defaults to `nil` for
  automatic device selection. The selected device must support the GPU/output
  combination. This is separate from the Vulkan renderer's `device` setting.
- `max_in_flight` — positive number of output buffers available at once;
  defaults to `2`. Increasing it allows the recipient to hold more frames,
  at the cost of memory.
- `on_backpressure` — currently only `:drop_new` (default). When every buffer
  is held by a recipient, new frames are dropped rather than growing the pool.

Each `VideoInterop.Frame` has a lease. Release it through `VideoInterop` when
finished; holding leases prevents their buffers from being reused.
All fields require a new viewport to change.

# `backpressure`

```elixir
@type backpressure() :: :drop_new
```

Drop a new frame when all output leases are in flight.

# `normalized_t`

```elixir
@type normalized_t() :: t()
```

Canonical form after nested keyword records have been expanded.

# `t`

```elixir
@type t() :: %Emerge.Config.PrimeFrames{
  device: String.t() | nil,
  max_in_flight: pos_integer(),
  on_backpressure: backpressure()
}
```

---

*Consult [api-reference.md](api-reference.md) for complete listing*