# Composite recording (/en/realtime-media/on-premise-recording/build/record-audio-and-video/composite-mode/linux-java)

> For AI agents: see the complete documentation index at [llms.txt](/llms.txt).

The On-Premise Recording SDK supports two recording modes:

* Individual recording mode: This is the default recording mode. The SDK generates one audio and/or video file for each UID.
* Composite recording mode: Generates a single mixed audio and video file for all UIDs in a channel, or mixes the audio of all UIDs in the channel into an audio file and the video of all UIDs into a video file.

See [Differences between individual recording mode and composite recording mode](/en/api-reference/faq/integration/recording_mode) to decide which mode you should use.

## Prerequisites

Before continuing, follow the [Quickstart](/en/realtime-media/on-premise-recording/quickstart) guide to integrate the Recording SDK and implement the basic recording functionality.

## Implement composite recording

The implementation of composite recording is largely similar to the steps in the [Quickstart](/en/realtime-media/on-premise-recording/quickstart) guide. The main differences are in the configuration parameters and the APIs used.

Refer to the following call sequence diagram to understand the recording workflow.

<details>
  <summary>
    Sequence diagram
  </summary>

  ![Sequence diagram](https://assets-docs.agora.io/images/on-premise-recording/composite-recording-logic.svg)
</details>

To implement composite recording in your app, follow these steps:

1. Initialize the recorder with [`enableMix`](/en/api-reference/api-ref/on-premise-recording#initialize) set to `true`.
2. Subscribe to the audio and video streams of the users you want to record.
3. Join the channel using [`joinChannel`](/en/api-reference/api-ref/on-premise-recording#joinchannel).
4. After joining the channel:
   * Use [`setRecorderConfig`](/en/api-reference/api-ref/on-premise-recording#setrecorderconfig) to set video resolution, frame rate, duration, and output path.
   * Optionally, use [`enableAndUpdateVideoWatermarks`](/en/api-reference/api-ref/on-premise-recording#enableandupdatevideowatermarks) to apply video watermarks.
   * Use [`setVideoMixingLayout`](/en/api-reference/api-ref/on-premise-recording#setvideomixinglayout) to configure the layout of multiple video streams.
5. Start and stop recording using:
   * [`startRecording`](/en/api-reference/api-ref/on-premise-recording#startrecording)
   * [`stopRecording`](/en/api-reference/api-ref/on-premise-recording#stoprecording)

Refer to the following code to implement these steps:

```java
// Initialize the recorder in composite recording mode
agoraMediaRtcRecorder.initialize(agoraService, true);

// Subscribe to all audio and video streams
agoraMediaRtcRecorder.subscribeAllAudio();
VideoSubscriptionOptions options = new VideoSubscriptionOptions();
options.setEncodedFrameOnly(false);
options.setType(Constants.VideoStreamType.VIDEO_STREAM_HIGH);
agoraMediaRtcRecorder.subscribeAllVideo(options);

// Join the channel
agoraMediaRtcRecorder.joinChannel(
    recorderConfig.getToken(),
    recorderConfig.getChannelName(),
    recorderConfig.getUserId()
);

// Configure the recorder
agoraMediaRtcRecorder.setRecorderConfig(recorderConfig);
agoraMediaRtcRecorder.enableAndUpdateVideoWatermarks(watermarks); // Optional
agoraMediaRtcRecorder.setVideoMixingLayout(layout);

// Start recording
agoraMediaRtcRecorder.startRecording();

// ...

// Stop recording
agoraMediaRtcRecorder.stopRecording();
```

## Reference

This section contains content that completes the information on this page, or points you to documentation that explains other aspects to this product.

### Considerations

The composite recording mode supports a specific set of APIs. Calling unsupported methods in the wrong mode has no effect. When using the composite recording mode, the following methods do not work:

* [`setRecorderConfigByUid`](/en/api-reference/api-ref/on-premise-recording#setrecorderconfigbyuid)
* [`enableAndUpdateVideoWatermarksByUid`](/en/api-reference/api-ref/on-premise-recording#enableandupdatevideowatermarksbyuid)
* [`startSingleRecordingByUid`](/en/api-reference/api-ref/on-premise-recording#startsinglerecordingbyuid)
* [`stopSingleRecordingByUid`](/en/api-reference/api-ref/on-premise-recording#stopsinglerecordingbyuid)