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本文总结三种用于安卓录屏的解决方案： adb shell命令screenrecord MediaRecorder， MediaProjection MediaProjection , MediaCodec和MediaMuxer screenrecord命令screenrecord是一个shell命令，支持Android4.4(API level 19)以上，录制的视频格式为mp4 ,存放到手机sd卡里，默认录制时间为180s adb shell screenrecord --size 1280*720 --bit-rate 6000000 --time-limit 30 /sdcard/demo.mp4 --size 指定视频分辨率； --bit-rate 指定视频比特率，默认为4M，该值越小，保存的视频文件越小； --time-limit 指定录制时长，若设定大于180，命令不会被执行； MediaRecorderMediaProjection是Android5.0后才开放的屏幕采集接口，通过系统级服务MediaProjectionManager进行管理。 录屏过程可以分成两个部分，即通过MediaProjectionManage申请录屏权限，用户允许后开始录制屏幕；然后通过MediaRecorder对音视频数据进行处理。 获取MediaProjectionManager实例 MediaProjectionManager mProjectionManager = (MediaProjectionManager) getSystemService("media_projection"); 申请权限 Intent captureIntent = mProjectionManager.createScreenCaptureIntent(); startActivityForResult(captureIntent, LOCAL_REQUEST_CODE);createScreenCaptureIntent()这个方法会返回一个intent，你可以通过startActivityForResult方法来传递这个intent，为了能开始屏幕捕捉，activity会提示用户是否允许屏幕捕捉（为了防止开发者做一个木马，来捕获用户私人信息），你可以通过getMediaProjection来获取屏幕捕捉的结果。 在onActivityResult中获取结果 @Override public void onActivityResult(int requestCode, int resultCode, Intent data) { MediaProjection mediaProjection = mProjectionManager.getMediaProjection(resultCode, data); if (mediaProjection == null) { Log.e(TAG, "media projection is null"); return; } File file = new File("xx.mp4"); //录屏生成文件 mediaRecord = new MediaRecordService(displayWidth, displayHeight, 6000000, 1, mediaProjection, file.getAbsolutePath()); mediaRecord.start(); } 创建MediaRecorder进程 package com.unionpay.service; import android.hardware.display.DisplayManager; import android.hardware.display.VirtualDisplay; import android.media.MediaRecorder; import android.media.projection.MediaProjection; import android.util.Log; public class MediaRecordService extends Thread { private static final String TAG = "MediaRecordService"; private int mWidth; private int mHeight; private int mBitRate; private int mDpi; private String mDstPath; private MediaRecorder mMediaRecorder; private MediaProjection mMediaProjection; private static final int FRAME_RATE = 60; // 60 fps private VirtualDisplay mVirtualDisplay; public MediaRecordService(int width, int height, int bitrate, int dpi, MediaProjection mp, String dstPath) { mWidth = width; mHeight = height; mBitRate = bitrate; mDpi = dpi; mMediaProjection = mp; mDstPath = dstPath; } @Override public void run() { try { initMediaRecorder(); //在mediarecorder.prepare()方法后调用 mVirtualDisplay = mMediaProjection.createVirtualDisplay(TAG + "-display", mWidth, mHeight, mDpi, DisplayManager.VIRTUAL_DISPLAY_FLAG_PUBLIC, mMediaRecorder.getSurface(), null, null); Log.i(TAG, "created virtual display: " + mVirtualDisplay); mMediaRecorder.start(); Log.i(TAG, "mediarecorder start"); } catch (Exception e) { e.printStackTrace(); } } /** * 初始化MediaRecorder * * @return */ public void initMediaRecorder() { mMediaRecorder = new MediaRecorder(); mMediaRecorder.setVideoSource(MediaRecorder.VideoSource.SURFACE); mMediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC); mMediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4); mMediaRecorder.setOutputFile(mDstPath); mMediaRecorder.setVideoSize(mWidth, mHeight); mMediaRecorder.setVideoFrameRate(FRAME_RATE); mMediaRecorder.setVideoEncodingBitRate(mBitRate); mMediaRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.H264); mMediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AAC); try { mMediaRecorder.prepare(); } catch (Exception e) { e.printStackTrace(); } Log.i(TAG, "media recorder" + mBitRate + "kps"); } public void release() { if (mVirtualDisplay != null) { mVirtualDisplay.release(); mVirtualDisplay = null; } if (mMediaRecorder != null) { mMediaRecorder.setOnErrorListener(null); mMediaProjection.stop(); mMediaRecorder.reset(); mMediaRecorder.release(); } if (mMediaProjection != null) { mMediaProjection.stop(); mMediaProjection = null; } Log.i(TAG, "release"); } } MediaCodec与MediaMuxerMediaCodec提供对音视频压缩编码和解码功能，MediaMuxer可以将音视频混合生成多媒体文件，生成MP4文件。 与MediaRecorder类似，都需要先通过MediaProjectionManager获取录屏权限，在回调中进行屏幕数据处理。 这里创建另一个进程： package com.unionpay.service; import java.io.IOException; import java.nio.ByteBuffer; import java.util.concurrent.atomic.AtomicBoolean; import android.hardware.display.DisplayManager; import android.hardware.display.VirtualDisplay; import android.media.MediaCodec; import android.media.MediaCodecInfo; import android.media.MediaFormat; import android.media.MediaMuxer; import android.media.projection.MediaProjection; import android.util.Log; import android.view.Surface; public class ScreenRecordService extends Thread{ private static final String TAG = "ScreenRecordService"; private int mWidth; private int mHeight; private int mBitRate; private int mDpi; private String mDstPath; private MediaProjection mMediaProjection; // parameters for the encoder private static final String MIME_TYPE = "video/avc"; // H.264 Advanced // Video Coding private static final int FRAME_RATE = 30; // 30 fps private static final int IFRAME_INTERVAL = 10; // 10 seconds between // I-frames private static final int TIMEOUT_US = 10000; private MediaCodec mEncoder; private Surface mSurface; private MediaMuxer mMuxer; private boolean mMuxerStarted = false; private int mVideoTrackIndex = -1; private AtomicBoolean mQuit = new AtomicBoolean(false); private MediaCodec.BufferInfo mBufferInfo = new MediaCodec.BufferInfo(); private VirtualDisplay mVirtualDisplay; public ScreenRecordService(int width, int height, int bitrate, int dpi, MediaProjection mp, String dstPath) { super(TAG); mWidth = width; mHeight = height; mBitRate = bitrate; mDpi = dpi; mMediaProjection = mp; mDstPath = dstPath; } /** * stop task */ public final void quit() { mQuit.set(true); } @Override public void run() { try { try { prepareEncoder(); mMuxer = new MediaMuxer(mDstPath, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4); } catch (IOException e) { throw new RuntimeException(e); } mVirtualDisplay = mMediaProjection.createVirtualDisplay(TAG + "-display", mWidth, mHeight, mDpi, DisplayManager.VIRTUAL_DISPLAY_FLAG_PUBLIC, mSurface, null, null); Log.d(TAG, "created virtual display: " + mVirtualDisplay); recordVirtualDisplay(); } finally { release(); } } private void recordVirtualDisplay() { while (!mQuit.get()) { int index = mEncoder.dequeueOutputBuffer(mBufferInfo, TIMEOUT_US); // Log.i(TAG, "dequeue output buffer index=" + index); if (index == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) { // 后续输出格式变化 resetOutputFormat(); } else if (index == MediaCodec.INFO_TRY_AGAIN_LATER) { // 请求超时 // Log.d(TAG, "retrieving buffers time out!"); try { // wait 10ms Thread.sleep(10); } catch (InterruptedException e) { } } else if (index >= 0) { // 有效输出 if (!mMuxerStarted) { throw new IllegalStateException("MediaMuxer dose not call addTrack(format) "); } encodeToVideoTrack(index); mEncoder.releaseOutputBuffer(index, false); } } } /** * 硬解码获取实时帧数据并写入mp4文件 * * @param index */ private void encodeToVideoTrack(int index) { // 获取到的实时帧视频数据 ByteBuffer encodedData = mEncoder.getOutputBuffer(index); if ((mBufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0) { // The codec config data was pulled out and fed to the muxer // when we got // the INFO_OUTPUT_FORMAT_CHANGED status. // Ignore it. Log.d(TAG, "ignoring BUFFER_FLAG_CODEC_CONFIG"); mBufferInfo.size = 0; } if (mBufferInfo.size == 0) { Log.d(TAG, "info.size == 0, drop it."); encodedData = null; } else { // Log.d(TAG, "got buffer, info: size=" + mBufferInfo.size + ", presentationTimeUs=" // + mBufferInfo.presentationTimeUs + ", offset=" + mBufferInfo.offset); } if (encodedData != null) { mMuxer.writeSampleData(mVideoTrackIndex, encodedData, mBufferInfo); } } private void resetOutputFormat() { // should happen before receiving buffers, and should only happen // once if (mMuxerStarted) { throw new IllegalStateException("output format already changed!"); } MediaFormat newFormat = mEncoder.getOutputFormat(); mVideoTrackIndex = mMuxer.addTrack(newFormat); mMuxer.start(); mMuxerStarted = true; Log.i(TAG, "started media muxer, videoIndex=" + mVideoTrackIndex); } private void prepareEncoder() throws IOException { MediaFormat format = MediaFormat.createVideoFormat(MIME_TYPE, mWidth, mHeight); format.setInteger(MediaFormat.KEY_COLOR_FORMAT, MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface); format.setInteger(MediaFormat.KEY_BIT_RATE, mBitRate); format.setInteger(MediaFormat.KEY_FRAME_RATE, FRAME_RATE); format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, IFRAME_INTERVAL); Log.d(TAG, "created video format: " + format); mEncoder = MediaCodec.createEncoderByType(MIME_TYPE); mEncoder.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE); mSurface = mEncoder.createInputSurface(); Log.d(TAG, "created input surface: " + mSurface); mEncoder.start(); } private void release() { if (mEncoder != null) { mEncoder.stop(); mEncoder.release(); mEncoder = null; } if (mVirtualDisplay != null) { mVirtualDisplay.release(); } if (mMediaProjection != null) { mMediaProjection.stop(); } if (mMuxer != null) { mMuxer.stop(); mMuxer.release(); mMuxer = null; } } }该进程只实现了视频录制，调用该进程只需修改主进程中的onActivityResult方法。 总结 MediaProjection似乎只有在屏幕发生变化时才传输，因此录屏推流的画面显得不够流畅 |
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