Watermark and Screenshot

2024-02-29

Feature Overview

When it is necessary to set copyright owner logos for educational teaching courseware and other scenarios, the SDK's watermark feature can be used.

This article mainly describes how to use the SDK to implement watermark and screenshot features.

Example Source Code Download

Please refer to Download Example Source Code to get the source code.

For related source code, please check the files in the "/ZegoExpressExample/Others/src/main/java/im/zego/others/beautyandwatermarkandsnapshot" directory.

Prerequisites

Before implementing watermark and screenshot features, please ensure:

You have created a project in the ZEGOCLOUD Console and applied for a valid AppID and AppSign. For details, please refer to Console - Project Information.
You have integrated the ZEGO Express SDK in your project and implemented basic audio and video streaming functionality. For details, please refer to Quick Start - Integration and Quick Start - Implementation.

Usage Steps

Watermark

Call ZegoWatermark to configure an image URL for a watermark and the size and position of the watermark in the picture.

Call the setPublishWatermark interface to set the publishing stream watermark.

Warning

Watermark images only support two image formats: "PNG" and "JPEG", that is, image files with three suffixes: ".png", ".jpg", ".jpeg".

The imageURL parameter in the ZegoWatermark object supports passing three path formats: absolute path, Assets, and Android URI path.

Absolute Path

file://[Absolute path of the image on the Android device]: You need to store the image in a directory of the Android device, for example, the private directory of the Android app: "/sdcard/Android/data/im.zego.zegoexpressapp/ZegoLogo.png".

// Supports JPG and PNG format images. If the image is placed in the assets directory of the Android project, imageURL must use "asset://" as a prefix. If it is an absolute path on the device, imageURL must use "file://" as a prefix + absolute path on the device
String imageURL = "file:///sdcard/Android/data/im.zego.zegoexpressapp/ZegoLogo.png";

// The upper left corner of the watermark layout is the origin of the coordinate system, and the area cannot exceed the size of the encoding resolution setting. If empty, it means canceling the watermark
Rect layout = new Rect(0,0,300,600);
ZegoWatermark watermark = new ZegoWatermark(imageURL, layout);
// Set watermark, supports dynamic modification during publishing stream
sdk.setPublishWatermark(watermark, true);

// Supports JPG and PNG format images. If the image is placed in the assets directory of the Android project, imageURL must use "asset://" as a prefix. If it is an absolute path on the device, imageURL must use "file://" as a prefix + absolute path on the device
String imageURL = "file:///sdcard/Android/data/im.zego.zegoexpressapp/ZegoLogo.png";

// The upper left corner of the watermark layout is the origin of the coordinate system, and the area cannot exceed the size of the encoding resolution setting. If empty, it means canceling the watermark
Rect layout = new Rect(0,0,300,600);
ZegoWatermark watermark = new ZegoWatermark(imageURL, layout);
// Set watermark, supports dynamic modification during publishing stream
sdk.setPublishWatermark(watermark, true);

Assets

asset://[Image resource name]: You need to store the image in the "assets" directory of the Android project.

// Supports JPG and PNG format images. If the image is placed in the assets directory of the Android project, imageURL must use "asset://" as a prefix. If it is an absolute path on the device, imageURL must use "file://" as a prefix + absolute path on the device
String imageURL = "asset://ZegoLogo.png";

// The upper left corner of the watermark layout is the origin of the coordinate system, and the area cannot exceed the size of the encoding resolution setting. If empty, it means canceling the watermark
Rect layout = new Rect(0,0,300,600);
ZegoWatermark watermark = new ZegoWatermark(imageURL,layout);
// Set watermark, supports dynamic modification during publishing stream
sdk.setPublishWatermark(watermark, true);

// Supports JPG and PNG format images. If the image is placed in the assets directory of the Android project, imageURL must use "asset://" as a prefix. If it is an absolute path on the device, imageURL must use "file://" as a prefix + absolute path on the device
String imageURL = "asset://ZegoLogo.png";

// The upper left corner of the watermark layout is the origin of the coordinate system, and the area cannot exceed the size of the encoding resolution setting. If empty, it means canceling the watermark
Rect layout = new Rect(0,0,300,600);
ZegoWatermark watermark = new ZegoWatermark(imageURL,layout);
// Set watermark, supports dynamic modification during publishing stream
sdk.setPublishWatermark(watermark, true);

Android URI Path

The Android URI path format is: String path = "uri://" + uri.toString();

// Must use "uri://" as a prefix
String imageURL = "uri://" + "content://com.android.providers.media.documents/document/image%3A1353";

// The upper left corner of the watermark layout is the origin of the coordinate system, and the area cannot exceed the size of the encoding resolution setting. If empty, it means canceling the watermark
Rect layout = new Rect(0,0,300,600);
ZegoWatermark watermark = new ZegoWatermark(imageURL,layout);
// Set watermark, supports dynamic modification during publishing stream
sdk.setPublishWatermark(watermark, true);

// Must use "uri://" as a prefix
String imageURL = "uri://" + "content://com.android.providers.media.documents/document/image%3A1353";

// The upper left corner of the watermark layout is the origin of the coordinate system, and the area cannot exceed the size of the encoding resolution setting. If empty, it means canceling the watermark
Rect layout = new Rect(0,0,300,600);
ZegoWatermark watermark = new ZegoWatermark(imageURL,layout);
// Set watermark, supports dynamic modification during publishing stream
sdk.setPublishWatermark(watermark, true);

Screenshot

After publishing stream, call the takePublishStreamSnapshot interface to take a screenshot of the publishing stream picture.

engine.takePublishStreamSnapshot(new IZegoPublisherTakeSnapshotCallback() {
    @Override
    public void onPublisherTakeSnapshotResult(int errorCode, Bitmap image) {
        //Save image
    }
});

engine.takePublishStreamSnapshot(new IZegoPublisherTakeSnapshotCallback() {
    @Override
    public void onPublisherTakeSnapshotResult(int errorCode, Bitmap image) {
        //Save image
    }
});

After playing stream, call the takePlayStreamSnapshot interface to take a screenshot of the playing stream picture.

engine.takePlayStreamSnapshot(streamID,new IZegoPlayerTakeSnapshotCallback() {
    @Override
    public void onPlayerTakeSnapshotResult(int errorCode, Bitmap image) {
        //Save image
    }
});
}

engine.takePlayStreamSnapshot(streamID,new IZegoPlayerTakeSnapshotCallback() {
    @Override
    public void onPlayerTakeSnapshotResult(int errorCode, Bitmap image) {
        //Save image
    }
});
}

FAQ

How to specify the imageURL in ZegoWatermark?

Supports images in JPG and PNG formats. If the image is placed in the "assets" directory folder of the Android project, imageURL must use "asset://" as a prefix. If it is an absolute path on the device, imageURL must use "file://" as a prefix + absolute path on the device.
How to specify the layout in ZegoWatermark?

The layout of the watermark cannot exceed the currently set video encoding resolution of the publishing stream. For setting the publishing stream encoding resolution, please refer to the setVideoConfig interface.