# TRTC_TranscodingConfigMode_Template_PresetLayout property Null safety

int TRTC_TranscodingConfigMode_Template_PresetLayout
final

Preset layout mode, where the layout of each channel of image is arranged in advance through placeholders. In this mode, you still need to set the `mixUsers` parameter, but you can set `userId` as a placeholder. Placeholder values include:

- "$PLACE_HOLDER_REMOTE$": image of remote user. Multiple images can be set.
- "$PLACE_HOLDER_LOCAL_MAIN$": local camera image. Only one image can be set.
- "$PLACE_HOLDER_LOCAL_SUB$": local screen sharing image. Only one image can be set. However, you don't need to listen on the `onUserVideoAvailable()` and `onUserAudioAvailable()` callbacks in `TRTCCloudDelegate` to make real-time adjustments. Instead, you only need to call `setMixTranscodingConfig()` once after successful room entry. Then, the SDK will automatically populate the placeholders you set with real `userId` values.

## Implementation

    static final int TRTC_TranscodingConfigMode_Template_PresetLayout = 3;