android - MediaRecorder 准备失败 : -2147483648 for nougat

Question

我正在编写一个应用程序来通过表面从相机录制视频。

以下代码用于准备MediaRecorder。

MediaRecorder mediaRecorder;
mediaRecorder = new MediaRecorder();
mediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);
        mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
        mediaRecorder.setOutputFile(videoFilename);
        mediaRecorder.setVideoEncodingBitRate(1000000);
        mediaRecorder.setVideoFrameRate(30);
        mediaRecorder.setVideoSize(videoSize.getWidth(), videoSize.getHeight());
        mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
        mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
        try {
            mediaRecorder.prepare();
        } catch (IOException e) {
            e.printStackTrace();
        }

像这样获取 outfile(videoFilename)，

File defaultExternalFolder = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM);
File videoFolder = new File(defaultExternalFolder, "My-Vids");
    if (!videoFolder.exists()) {
        videoFolder.mkdir();
    }

String timestemp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String prepend = "MyVid_" + timestemp + "_";
File videoFile = File.createTempFile(prepend, ".mp4", videoFolder);
videoFilename = videoFile.getAbsolutePath();
return videoFile;

videoSize 只是一个对象大小类。

当我尝试启动 MediaRecorder 时，我得到 java.io.IOException: prepare failed.

奇怪的是它仅在 Nougat OS 中崩溃，在其他设备中它工作正常。

Answer 1

我猜你是在模拟器上运行这段代码。实际上，模拟器不支持 MediaRecorder。参见:MediaRecorder

Note: Currently, MediaRecorder does not work on the emulator.

好吧，你可以通过评论 Mic config 来测试它，你会看到它的工作。

MediaRecorder mediaRecorder;
mediaRecorder = new MediaRecorder();
mediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE);
//mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
mediaRecorder.setOutputFile(videoFilename);
mediaRecorder.setVideoEncodingBitRate(1000000);
mediaRecorder.setVideoFrameRate(30);
mediaRecorder.setVideoSize(videoSize.getWidth(), videoSize.getHeight());
mediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264);
//mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC);
try {
    mediaRecorder.prepare();
} catch (IOException e) {
    e.printStackTrace();
}

我已经在 Android 7.1 (Samsung Galaxy S8) 上测试了您的代码及其工作情况。仅在模拟器上出现问题。