Android录制视频分段保留的探究
Android录制视频分段保存的探究
录制视频需要分段保存,可以从系统源码考虑,看了以下一些代码:
- framework/av/media/libstagefright/MPEG4Writer.cpp
- package/apps/Camera/src/com/android/camera/actor/VideoActor.java
主要从MPEG4Writer.cpp中的kMax32BitFileSize 和入手,如下,修改单个文件最大容量为56M(0x3800000),发现利用系统Camera录像时,到达阀值后会提示“已达到大小上限”,并自动停止,保存已经录制的视频。
static const int64_t kMax32BitFileSize = 0x3800000;//0x00ffffffffLL; // 2^32-1 : max FAT32 static const int64_t kMax32BitDuration = 0x007fffffffLL;
然后追踪到VideoActor的处理。有一个思路,就是停止的时候,进行文件保存后立即重新启动录像。
public void stopVideoRecordingAsync() { // TChip ZJ // for snapshot stopObjectTracking(); mStopVideoRecording = true; Log.d(TAG, "stopVideoRecordingAsync() mMediaRecorderRecording=" + mMediaRecorderRecording + ", mRecorderBusy=" + mRecorderBusy + ", isVideoProcessing()" + isVideoProcessing() + ", mStopVideoRecording =" + mStopVideoRecording); mVideoContext.getZoomManager().changeZoomForQuality(); mVideoContext.setSwipingEnabled(true); mHandler.removeMessages(UPDATE_RECORD_TIME); mVideoContext.getShutterManager().setVideoShutterMask(false); if (isVideoProcessing()) { return; } if (mRecorderBusy) { // return for recorder is busy. return; } mRecorderBusy = true; mRecordingView.hide(); if (mMediaRecorderRecording) { mVideoContext.getShutterManager().setVideoShutterEnabled(false); if (mStoppingAction != STOP_RETURN_UNVALID && mCallFromOnPause != true) { // mVideoContext.showProgress(mVideoContext.getResources().getString(R.string.saving)); // TChip ZJ : 去掉保存UI } mVideoSavingTask = new SavingTask(); mVideoSavingTask.start(); } else { mRecorderBusy = false; releaseRecorder(); if (mStoppingAction == STOP_RETURN_UNVALID) { doReturnToCaller(false); } } }
先吃饭了,明天再看实现的可行性以及效果(是否漏秒)。 继续追踪
看了下保存的逻辑,涉及以下两处源码:
packages/apps/Camera/src/com/android/camera/manager/MMProfileManager.java mediatek/frameworks/base/mmprofile/java/com/mediatek/mmprofile/MMProfileManager.java
然后从MMProfileManager定位到MMProfile:
mediatek/frameworks/base/mmprofile/java/com/mediatek/mmprofile/MMProfile.java
这个类比较简单,加载了JNI库,再追下去就到c了。
public class MMProfile { static { System.loadLibrary("mmprofile_jni"); } public static final int MMP_RootEvent = 1; // MMP_LogType public static final int MMProfileFlagStart = 1; public static final int MMProfileFlagEnd = 2; public static final int MMProfileFlagPulse = 4; public static final int MMProfileFlagEventSeparator = 8; public static final int MMProfileFlagSystrace = 0x80000000; public native static int MMProfileRegisterEvent(int parent, String name); public native static int MMProfileFindEvent(int parent, String name); public native static void MMProfileEnableEvent(int event, int enable); public native static void MMProfileEnableEventRecursive(int event, int enable); public native static int MMProfileQueryEnable(int event); public native static void MMProfileLog(int event, int type); public native static void MMProfileLogEx(int event, int type, int data1, int data2); public native static int MMProfileLogMetaString(int event, int type, String str); public native static int MMProfileLogMetaStringEx(int event, int type, int data1, int data2, String str); }