setOutputFormat在无效状态下调用:4(在何处以及为什么)

问题描述

我有以下代码:

Log.i("xx","A");
                 media_recorder = new MediaRecorder();
Log.i("xx","B");
                 media_recorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
Log.i("xx","C");
                 media_recorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
Log.i("xx","D");
                 media_recorder.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);
Log.i("xx","E");
                 media_recorder.setVideoSize(320, 240);
Log.i("xx","F");
                 media_recorder.setVideoFrameRate(15);
Log.i("xx","G");
                 CamcorderProfile profile = CamcorderProfile.get(CameraInfo.CAMERA_FACING_FRONT,CamcorderProfile.QUALITY_LOW);
Log.i("xx","H");
                 media_recorder.setProfile(profile);
Log.i("xx","I");
                 media_recorder.setOutputFile(fname);

执行代码后，我在日志中看到以下内容；

When the code is executed, I see the following in my logs;

02-07 16:12:47.628: I/xx(15436): A
02-07 16:12:47.628: I/xx(15436): B
02-07 16:12:47.638: I/xx(15436): C
02-07 16:12:47.638: I/xx(15436): D
02-07 16:12:47.638: I/xx(15436): E
02-07 16:12:47.638: I/xx(15436): F
02-07 16:12:47.638: I/xx(15436): G
02-07 16:12:47.638: I/xx(15436): H
02-07 16:12:47.638: E/MediaRecorder(15436): setOutputFormat called in an invalid state: 4

这让我感到困惑，因为对 setOutputFormat 的调用是在"C"和"D"之间进行的，但是错误的报告似乎紧接在H之后(从未到达"I").所以现在我不知道是什么导致了错误，并且我对错误发生的位置感到困惑.

This has confused me because the call to setOutputFormat was made between "C" and "D", but the report of the error appears to be immediately after H (never reaching "I"). So now I don't know what is causing the error, and I'm confused about where the error is occurring.

编辑:我只是逐步调试了调试器中的代码-并确定在调用setProfile(profile)期间发生了足够的错误...因此，似乎是对setOutputFormat的调用(在"C"和"D"之间)必须工作正常，但是setProfile必须本身再次调用setOutputFormat，然后失败...这是怎么回事?

I just stepped through the code in the debugger - and sure enough the error occurs during the call to setProfile(profile)... so it would appear that the call made to setOutputFormat (between "C" & "D") must have worked ok, but then setProfile must itself make a second call to setOutputFormat which then fails... is that what's going on?

编辑:无效状态4的实际含义是什么?某处是否有列表告诉您每个可能的无效状态编号1,2,3,4 ...等等的含义?

And what does invalid state 4 actually mean? Is there some list somewhere which tells you the meaning of each possible invalid state number 1,2,3,4...etc?

推荐答案

这是 setProfile 方法的源代码:

public void setProfile(CamcorderProfile profile) {
  setOutputFormat(profile.fileFormat);
  setVideoFrameRate(profile.videoFrameRate);
  setVideoSize(profile.videoFrameWidth, profile.videoFrameHeight);
  setVideoEncodingBitRate(profile.videoBitRate);
  setVideoEncoder(profile.videoCodec);
  if (profile.quality >= CamcorderProfile.QUALITY_TIME_LAPSE_LOW &&
      profile.quality <= CamcorderProfile.QUALITY_TIME_LAPSE_QVGA) {
   // Nothing needs to be done. Call to setCaptureRate() enables
   // time lapse video recording.
  } else {
    setAudioEncodingBitRate(profile.audioBitRate);
    setAudioChannels(profile.audioChannels);
    setAudioSamplingRate(profile.audioSampleRate);
    setAudioEncoder(profile.audioCodec);
  }
}

例如它将outputFormat，videoSize，encoder和frameRate设置为配置文件中的值.所以你的代码:

E.g. it sets outputFormat, videoSize, encoder and frameRate to values from profile. So your code:

Log.i("xx","C");
media_recorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
Log.i("xx","D");
media_recorder.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);
Log.i("xx","E");
media_recorder.setVideoSize(320, 240);
Log.i("xx","F");
media_recorder.setVideoFrameRate(15);

至少是无用的，也许在这些调用期间它会更改状态.尝试不使用它.

is at least useless, and maybe during these calls it changes state. Try without it.

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