Client-side local recording

How it works

During a call, you can record local audio and video streams using two APIs:

API	Description	Parameters
`startRecord`	Starts a local recording session with the specified parameters.	`recordType`: The recording type. Valid values: audio-only or audio and video. `recordFormat`: The format of the recording file. For audio-only recording, AAC and WAV are supported. For audio and video recording, MP4 is supported. `filePath`: The path where the recording file is saved. `audioConfig`: Audio recording settings, such as sample rate, quality, and options for recording audio from external capture or playback sources. `videoConfig`: Video recording settings, such as video quality and encoding mode. `maxSize`: The maximum file size in bytes. Recording stops automatically when this limit is reached. `maxDuration`: The maximum recording duration in seconds. Recording stops automatically when this limit is reached.
`stopRecord`	Stops the local recording and saves the file.	None.

Sample code

Local recording on Android: Android/ARTCExample/AdvancedUsage/src/main/java/com/aliyun/artc/api/advancedusage/LocalRecord/RecordingActivity.java

Local recording on iOS: iOS/ARTCExample/AdvancedUsage/LocalRecording/RecordingVC.swift

Prerequisites

Before you start, make sure you have completed the following:

Created a Real-time Communication (RTC) application in the Alibaba Cloud console. For instructions, see Create an application. You will need the App ID and App Key from the RTC console.
Integrated the ARTC SDK into your project and implemented basic real-time audio and video functionality. For instructions, see SDK download and integration and Implement audio and video calls.

Implementation

1. Configure recording settings

Before calling startRecord, publish a stream first. After a state change callback confirms successful publication, configure the recording parameters.

Android

AliRtcEngine.AliRtcRecordType recordType = AliRtcEngine.AliRtcRecordType.AliRtcRecordTypeVideo;  // Set the record type: audio-only or audio and video.
AliRtcEngine.AliRtcRecordFormat recordFormat = AliRtcEngine.AliRtcRecordFormat.AliRtcRecordFormatMP4; // Set the recording format. Audio-only: AAC, WAV; Audio and video: MP4.
String filePath = getApplicationContext().getExternalFilesDir( null) + "/record"; // Specify the save path.
Log.i("startRecord", "filePath:" + filePath);
// Configure audio recording settings.
AliRtcEngine.AliRtcRecordAudioConfig audioConfig = new AliRtcEngine.AliRtcRecordAudioConfig();
audioConfig.sampleRate = AliRtcEngine.AliRtcAudioSampleRate.AliRtcAudioSampleRate_48000; // Sample rate.
audioConfig.quality = AliRtcEngine.AliRtcAudioQuality.AliRtcAudioQualityHigh;  // Higher quality results in a larger file size.
audioConfig.externalPcmCaptureRecording = true;  // Enables recording from an external capture source.
audioConfig.externalPcmRenderRecording = true;   // Enables recording from an external render (playback) source.

// Configure video recording settings.
AliRtcEngine.AliRtcRecordVideoConfig videoConfig = new AliRtcEngine.AliRtcRecordVideoConfig();
videoConfig.quality = AliRtcEngine.AliRtcVideoQuality.AliRtcVideoQualityDefault;
videoConfig.encodeMode = AliRtcEngine.AliRtcRecordVideoEncodeMode.AliRtcRecordReusingEncoderMode;  // Reuse the encoder used for publishing.

long maxSize = -1; // Maximum file size in bytes. Recording stops automatically when this limit is reached.
long maxDuration = -1; // Maximum recording duration in seconds. Recording stops automatically when this limit is reached.

iOS

// Set the record type. This example records both audio and video.
let recordType:AliRtcRecordType = .video // Includes both audio and video, supports MP4 format.
// Set the recording format.
let recordFormat: AliRtcRecordFormat = .MP4
// Set the path to save the recording file (app sandbox directory).
let fileDirectory = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first!
let filePath = (fileDirectory as NSString).appendingPathComponent("record")
let fm = FileManager.default
if !fm.fileExists(atPath: filePath) {
    try? fm.createDirectory(atPath: filePath, withIntermediateDirectories: true, attributes: nil)
}

// Configure audio recording settings based on your needs.
var audioConfig = AliRtcRecordAudioConfig(
    sampleRate: ._48000,                    // Sample rate: 48000 Hz.
    quality: .high,                         // High audio quality.
    enableRecordExternalRenderPCM: true,    // Allows recording audio from a custom render (playback) source.
    enableRecordExternalCapturePCM: true    // Allows recording audio from a custom capture source.
)
// Configure video recording settings.
var videoConfig = AliRtcRecordVideoConfig(
    quality: .default,
    sourceType: .video,
    canvas: AliRtcRecordVideoCanvasConfig(canvasWidth: 720, canvasHeight: 1280),
    fps: 30,
    bitrate: 1200
)
// Set limits for file size and duration.
let maxSize: Int64 = -1     // Unit: bytes.
let maxDuration: Int32 = -1 // Unit: seconds.

macOS

/*
   Configure audio settings
*/
    AliRtcRecordAudioConfig AudioConfig ;
    AudioConfig.quality = AliRtcAudioQualityMidium ;
    AudioConfig.sampleRate = AliRtcAudioSampleRate_48000 ;
    AudioConfig.enableRecordExternalCapturePCM = false ;
    AudioConfig.enableRecordExternalRenderPCM = false ;

/*
   Configure video settings
*/
    AliRtcRecordVideoConfig VideoConfig ;
    VideoConfig.sourceType = AliRtcVideosourceCameraType ;
    VideoConfig.bitrate = view.bitrate ;
    VideoConfig.fps = 20 ;
    VideoConfig.quality = AliRtcVideoQualityDefault ;

Windows

AliEngineRecordFormat recordFormat = AliEngineRecordFormatMP4; // Recording format. Audio: AAC, WAV; Video: MP4.
std::string filePath = "D:\\record_tmp\\record_video.mp4"; // Save path.

// Audio recording configuration.
AliEngineRecordAudioConfig audioConfig;
audioConfig.sampleRate = AliEngineAudioSampleRate_48000; // Sample rate.
audioConfig.quality = AliEngineAudioQualityHigh;  // Higher quality results in a larger file size.
audioConfig.externalPcmCaptureRecording = true;  // Enables recording from an external capture source.
audioConfig.externalPcmRenderRecording = true;   // Enables recording from an external render (playback) source.

// Video recording configuration.
AliEngineRecordVideoConfig videoConfig;
videoConfig.quality = AliEngineVideoQualityDefault;
// The current version only supports reusing the encoder used for publishing.
videoConfig.encodeMode = AliEngineRecordVideoReusingEncoderMode;  

AliEngineRecordType recordType = AliEngineRecordTypeVideo;

2. Start recording

Call startRecord with your configured settings. On success, the SDK begins recording the audio and video streams.

Android

mAliRtcEngine.startRecord(recordType, recordFormat, filePath, audioConfig, videoConfig, maxSize, maxDuration);

iOS

let result = withUnsafeMutablePointer(to: &audioConfig, { audioPtr in
    withUnsafeMutablePointer(to: &videoConfig, { videoPtr in
        engine.start(
            recordType,
            recordFormat: recordFormat,
            filePath: filePath,
            audioConfig: audioPtr,
            videoConfig: videoPtr
        )
    })
})

macOS

 BOOL ret = [self.engine startRecord:AliRtcRecordTypeVideo recordFormat:AliRtcRecordFormatMP4
                    filePath:view.recordFilePath audioConfig:&AudioConfig videoConfig:&VideoConfig isFragment:FALSE] ;

Windows

mAliRtcEngine->StartRecord(recordType, recordFormat, filePath.c_str(), audioConfig, videoConfig, false);

3. Stop recording

To stop the recording manually, call the stopRecord method.

Android

mAliRtcEngine.stopRecord();

iOS

rtcEngine?.stopRecord()

macOS

[self.engine stopRecord];

Windows

mAliRtcEngine->StopRecord();

4. Retrieve the recording file

After the recording stops, the file is saved to the specified path. You can then upload it to a server, play it back, or delete it.

Note

Ensure that your application has the necessary storage permissions, such as WRITE_EXTERNAL_STORAGE on Android.
On low-performance devices, consider reducing the recording quality to maintain a smooth call experience.