Mtk平台录像失败的简单分析

（1）Mtk提供的FAQ分析

https://online.mediatek.com/FAQ#/SW/FAQ21583

（2）MediaRecorder没有录取到数据的报错

07-04 19:23:41.029   645  7726 E MPEG4Writer: The number of recorded samples is 0
07-04 19:23:41.029   645  7726 E MPEG4Writer: 0 frames to dump timeStamps in Video track 
07-04 19:23:41.030   645  7726 I MPEG4Writer: Received total/0-length (0/0) buffers and encoded 0 frames. - Video
07-04 19:23:51.058   645  1823 E MPEG4Writer: Stop() called but track is not started or stopped
07-04 19:23:51.065  7146  7146 E MediaRecorder: stop failed: -1007 0xa983cb80

07-04 19:23:51.155  7146  7167 E TestRunner: java.lang.RuntimeException: stop failed.
07-04 19:23:51.155  7146  7167 E TestRunner: 	at android.media.MediaRecorder.stop(Native Method)
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以上信息表示最终buffer没有写进MPEG4Writer。

可从以下方面进行检查：

（A）关掉fuse尝试

//可以输入如下命令关掉fuse，看一下是否是fuse导致的 
adb root
adb shell setprop persist.sys.fflag.override.settings_fuse false
adb shell setprop persist.sys.fuse false
adb reboot

//或者使用settings：
Settings->System->Developer options->Feature flags 
Close the settings_fuse item, then restart the phone

//查看是否已关闭：
adb shell "mount | grep fuse"

none on /sys/fs/fuse/connections type fusectl (rw,relatime)
/dev/fuse on /mnt/user/0/emulated type fuse (rw,lazytime,nosuid,nodev,noexec,noatime,user_id=0,group_id=0,allow_other)
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（B）metadata当中MTK_SENSOR_INFO_TIMESTAMP_SOURCE配置的检查

//低端平台不支持MTK_SENSOR_INFO_TIMESTAMP_SOURCE_REALTIME
CONFIG_ENTRY_VALUE(MTK_SENSOR_INFO_TIMESTAMP_SOURCE_REALTIME, MUINT8)

CONFIG_ENTRY_VALUE(MTK_SENSOR_INFO_TIMESTAMP_SOURCE_UNKNOWN, MUINT8)
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（3）CTS测试出现的Fail项

例如如下两项：

• CtsCameraTestCases——android.hardware.cts.CameraTest#testRecordingHint()
• CtsCameraTestCases——android.hardware.cts.CameraTest#testLockUnlock()

我们这里以testRecordingHint为例，简单看一下最终调用到的源码。

private void recordVideoSimple(CamcorderProfile profile,
              SurfaceHolder holder) throws Exception {
          mCamera.unlock();
          MediaRecorder recorder = new MediaRecorder();
          try {
              recorder.setCamera(mCamera);
              recorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
              recorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
              recorder.setProfile(profile);
              recorder.setOutputFile(mRecordingPath);
              recorder.setPreviewDisplay(holder.getSurface());
              recorder.prepare();
              recorder.start();
              Thread.sleep(2000);
              recorder.stop();
          } finally {
              recorder.release();
              mCamera.lock();
          }
      }
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可以看到这里也有录像测试，此时测试Fail的原因如下：

//Fail原因
07-04 19:23:41.029   645  7726 E MPEG4Writer: The number of recorded samples is 0
07-04 19:23:41.029   645  7726 E MPEG4Writer: 0 frames to dump timeStamps in Video track 
07-04 19:23:41.030   645  7726 I MPEG4Writer: Received total/0-length (0/0) buffers and encoded 0 frames. - Video

//Fail Log选择的Size
07-04 19:23:29.891  6313  6313 I mtkcam-dev3-utils: [beginConfigureStreams] stream re-configuration: streamId:0 type(0:0) size(1920x1080:1920x1080) format(34:34) dataSpace(0:0) usage(0x900:0x900)

//Pass Log选择的Size
07-04 20:57:13.285   717   717 I mtkcam-dev3-utils: [beginConfigureStreams] stream re-configuration: streamId:0 type(0:0) size(1280x720:1280x720) format(34:34) dataSpace(0:0) usage(0x900:0x900)
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通过排查发现是需要进行如下修改才可以Pass，移除对应1080P的Preview选项。

//vendor/mediatek/proprietary/custom/mtxxxx/hal/imgsensor_metadata/common/config_static_metadata_project.h
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具体原因应该是1080P超出了2M的Sensor的Spec，进而导致Sensor不出数据，最终没有数据写入MPEG4Writer。