How to Convert Screenshot Stream Properly？

[anjiuzhe]

hello,In Java I take a screenshot of the device with the following adb command, and when I convert the stream to an image, I get an incorrect image, the code looks like this:

String command = String.format("adb shell CLASSPATH=/data/local/tmp/minicap-devel/minicap-debug.apk app_process /system/bin io.devicefarmer.minicap.Main -P %s@%s/0 -s", screenSize, screenSize);
ProcessBuilder processBuilder = new ProcessBuilder(command.split(" "));
Process process = processBuilder.start();
InputStream inputStream = process.getInputStream();
BufferedInputStream bis = new BufferedInputStream(inputStream);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int bytesRead;
while ((bytesRead = bis.read(buffer)) != -1) {
    byteArrayOutputStream.write(buffer, 0, bytesRead);
}
byte[] imageBytes = byteArrayOutputStream.toByteArray();
InputStream byteArrayInputStream = new ByteArrayInputStream(imageBytes);
BufferedImage bufferedImage = ImageIO.read(byteArrayInputStream);
if (bufferedImage == null) {
    throw new IOException("Failed to decode image from input stream.");
}
File outFile = new File(savePath);
ImageIO.write(bufferedImage, "jpg", outFile);

the image looks like this:

However, when I modify the source code of the minicap-debug.apk, the Screenshot Output sent to the screenshot stream is changed here to look like this:

class ScreenshotOutput(private val output: PrintStream) : DisplayOutput() {

    override fun send() {
        val writer = PrintWriter(output)
        writer.use {
            val encodedImage: String = Base64.encodeToString(imageBuffer.toByteArray(), Base64.DEFAULT)
            it.write(encodedImage)
            it.flush()
        }
    }
}

On the java side, the screenshot stream is decoded in Base 64 and then converted to obtain the correct image,java changed here to look like this:

String command = String.format("adb shell CLASSPATH=/data/local/tmp/minicap-devel/minicap-debug.apk app_process /system/bin io.devicefarmer.minicap.Main -P %s@%s/0 -s", screenSize, screenSize);
ProcessBuilder processBuilder = new ProcessBuilder(command.split(" "));
Process process = processBuilder.start();
InputStream inputStream = process.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
StringBuilder stringBuilder = new StringBuilder();
String line;
while ((line = reader.readLine()) != null) {
    stringBuilder.append(line);
}
reader.close();
// Decode the Base64 string to byte array
byte[] imageBytes = Base64.getDecoder().decode(stringBuilder.toString());
// Convert byte array to BufferedImage
InputStream byteArrayInputStream = new ByteArrayInputStream(imageBytes);
BufferedImage bufferedImage = ImageIO.read(byteArrayInputStream);
if (bufferedImage == null) {
    throw new IOException("Failed to decode image from input stream.");
}
// Write the BufferedImage to file
File outFile = new File(savePath);
ImageIO.write(bufferedImage, "jpg", outFile);

The image I get after the modification is very correct, I want to know how to parse the image correctly when not using Base 64, thank you