安卓相机视频为空白，有白线

Question 1

我使用 MediaRecorder 实现了Android的Camera2 API，从相机中录制视频。相机预览工作正常，视频文件也成功创建，没有任何错误。然而，输出的视频是空白的，有白色的闪烁线。

This is the output video I get.

准备 MediaRecorder 的代码

val surface = MediaCodec.createPersistentInputSurface()
surface.release()
val outputFile = createFile(applicationContext,"mp4")
val mMediaRecorder = MediaRecorder()
mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC)
mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE)
mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4)
mMediaRecorder.setOutputFile(outputFile.absolutePath)
mMediaRecorder.setVideoEncodingBitRate(10_000_000)
mMediaRecorder.setVideoFrameRate(30)
mMediaRecorder.setVideoSize(matchedResolution.width, matchedResolution.height)
mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264)
mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC)
mMediaRecorder.setInputSurface(surface)
创建会议。
val previewSurface = surfaceView2.holder.surface
val captureCallbackVideo =
    object : CameraCaptureSession.StateCallback() {
        override fun onConfigureFailed(session: CameraCaptureSession) {}
        override fun onConfigured(session: CameraCaptureSession) {
            // session configured
            val previewRequestBuilder =
                cameraDevice.createCaptureRequest(TEMPLATE_RECORD)
                    .apply {
                        addTarget(previewSurface)
                        addTarget(surface)
                        set(CaptureRequest.CONTROL_AE_TARGET_FPS_RANGE, Range(30,30))
            session.setRepeatingRequest(
                previewRequestBuilder.build(),
                null,
                Handler { true }
cameraDevice.createCaptureSession(mutableListOf(previewSurface, surface), captureCallbackVideo, Handler { true })
用于开始录音
mMediaRecorder.prepare()
mMediaRecorder.start()
For stopping
mMediaRecorder.stop()
mMediaRecorder.release()

Question 2


          
           
            
             
              我已经明白了。问题出在
              
               MediaRecorder
              
              的输入面。显然，谷歌在GitHub上的
              
               camera2
              
              的代码方式在为
              
               MediaRecorder
              
              正确设置
              
               Surface
              
              时是不正确的。
             
             
              解决办法是，我们不应该向MediaRecorder提供
              
               Surface
              
              作为输入，而是
              
               prepare
              
              的
              
               MediaRecorder
              
              ，没有
              
               Surface
              
              ，然后使用其内部的
              
               Surface
              
              为我们的
              
               CaptureRequest
              
              。
             
             mMediaRecorder = MediaRecorder()
mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE)
mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4)
mMediaRecorder.setVideoEncodingBitRate(10_000_000)
//Uncomment on physical device, comment on emulator
//mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264)
mMediaRecorder.setVideoSize(matchedResolution.width, matchedResolution.height)
mMediaRecorder.setVideoFrameRate(30)
mMediaRecorder.setOutputFile(outputFile.absolutePath)
try {
    mMediaRecorder.prepare()
} catch (e: java.lang.Exception) {
    e.printStackTrace()
    return
用于创建会话
val previewSurface = surfaceView2.holder.surface
val captureCallbackVideo =
    object : CameraCaptureSession.StateCallback() {
        override fun onConfigureFailed(session: CameraCaptureSession) {}
        override fun onConfigured(session: CameraCaptureSession) {
            // session configured
            val previewRequestBuilder =
                cameraDevice.createCaptureRequest(TEMPLATE_RECORD)
                    .apply {
                        addTarget(previewSurface)
                        addTarget(mMediaRecorder.surface)
                        set(CaptureRequest.CONTROL_AE_TARGET_FPS_RANGE, Range(30,30))
            session.setRepeatingRequest(
                previewRequestBuilder.build(),
                null,
                Handler { true }
cameraDevice.createCaptureSession(mutableListOf(previewSurface, mMediaRecorder.surface), captureCallbackVideo, Handler { true })
用于开始录音。
mMediaRecorder.start()
用于停止录音。
mMediaRecorder.stop()
mMediaRecorder.release()

Question 3


          
           
            
             
              
               
                
                 
                  你可以使用以下代码，我认为这可能是setVideoEncodingBitRate的问题。
                 
                 recorder.setVideoSize(640, 480);