Android平台實現屏幕采集並推送至RTMP服務器

隨着無紙化、智慧教室等場景的普及，好多企業或者開發者開始尋求更高效穩定低延遲的RTMP同屏方案，本文以大牛直播SDK(Github)的同屏demo（對應工程：SmartServicePublisherV2）為例，介紹下如何采集編碼推送RTMP數據到流媒體服務器。

系統要求：Android 5.0及以上系統。

廢話不多說，上代碼：

獲取screen windows寬高，如需縮放，按照一定的比例縮放即可：

    private void createScreenEnvironment() {

        sreenWindowWidth = mWindowManager.getDefaultDisplay().getWidth();
        screenWindowHeight = mWindowManager.getDefaultDisplay().getHeight();

        Log.i(TAG, "screenWindowWidth: " + sreenWindowWidth + ",screenWindowHeight: "
                + screenWindowHeight);

        if (sreenWindowWidth > 800)
        {
            if (screenResolution == SCREEN_RESOLUTION_STANDARD)
            {
                scale_rate = SCALE_RATE_HALF;
                sreenWindowWidth = align(sreenWindowWidth / 2, 16);
                screenWindowHeight = align(screenWindowHeight / 2, 16);
            }
            else if(screenResolution == SCREEN_RESOLUTION_LOW)
            {
                scale_rate = SCALE_RATE_TWO_FIFTHS;
                sreenWindowWidth = align(sreenWindowWidth * 2 / 5, 16);

            }
        }

        Log.i(TAG, "After adjust mWindowWidth: " + sreenWindowWidth + ", mWindowHeight: " + screenWindowHeight);

        int pf = mWindowManager.getDefaultDisplay().getPixelFormat();
        Log.i(TAG, "display format:" + pf);

        DisplayMetrics displayMetrics = new DisplayMetrics();
        mWindowManager.getDefaultDisplay().getMetrics(displayMetrics);
        mScreenDensity = displayMetrics.densityDpi;

        mImageReader = ImageReader.newInstance(sreenWindowWidth,
                screenWindowHeight, 0x1, 6);

        mMediaProjectionManager = (MediaProjectionManager) getSystemService(Context.MEDIA_PROJECTION_SERVICE);
    }

獲取到image數據后，傳遞到processScreenImage()處理：

   private void setupMediaProjection() { mMediaProjection = mMediaProjectionManager.getMediaProjection( MainActivity.mResultCode, MainActivity.mResultData); } private void setupVirtualDisplay() { mVirtualDisplay = mMediaProjection.createVirtualDisplay( "ScreenCapture", sreenWindowWidth, screenWindowHeight, mScreenDensity, DisplayManager.VIRTUAL_DISPLAY_FLAG_AUTO_MIRROR, mImageReader.getSurface(), null, null); mImageReader.setOnImageAvailableListener( new ImageReader.OnImageAvailableListener() { @Override public void onImageAvailable(ImageReader reader) { Image image = mImageReader.acquireLatestImage(); if (image != null) { processScreenImage(image); //image.close(); } } }, null); }

數據放到image list里面：

    private void pushImage(Image image) { if ( null ==image ) return; final int image_list_max_count = 1; LinkedList<Image> close_images = null; synchronized (image_list_lock) { if (image_list.size() > image_list_max_count ) { close_images = new LinkedList(); while ( image_list.size() > image_list_max_count) { close_images.add(image_list.poll()); } } image_list.add(image); } if ( close_images != null ) { while( !close_images.isEmpty() ) { Image i = close_images.poll(); if ( i != null ) { i.close(); //Log.i("PushImage", "drop image"); } } } }

調用大牛直播SDK的RTMP初始化和參數設置接口：

        libPublisher = new SmartPublisherJniV2(); private void InitAndSetConfig() { //開始要不要采集音頻或視頻，請自行設置 publisherHandle = libPublisher.SmartPublisherOpen(this.getApplicationContext(), audio_opt, video_opt, sreenWindowWidth, screenWindowHeight); if ( publisherHandle == 0 ) { return; } Log.i(TAG, "publisherHandle=" + publisherHandle); libPublisher.SetSmartPublisherEventCallbackV2(publisherHandle, new EventHandeV2()); if(videoEncodeType == 1) { int h264HWKbps = setHardwareEncoderKbps(true, sreenWindowWidth, screenWindowHeight); Log.i(TAG, "h264HWKbps: " + h264HWKbps); int isSupportH264HWEncoder = libPublisher .SetSmartPublisherVideoHWEncoder(publisherHandle, h264HWKbps); if (isSupportH264HWEncoder == 0) { Log.i(TAG, "Great, it supports h.264 hardware encoder!"); } } else if (videoEncodeType == 2) { int hevcHWKbps = setHardwareEncoderKbps(false, sreenWindowWidth, screenWindowHeight); Log.i(TAG, "hevcHWKbps: " + hevcHWKbps); int isSupportHevcHWEncoder = libPublisher .SetSmartPublisherVideoHevcHWEncoder(publisherHandle, hevcHWKbps); if (isSupportHevcHWEncoder == 0) { Log.i(TAG, "Great, it supports hevc hardware encoder!"); } } if(is_sw_vbr_mode) { int is_enable_vbr = 1; int video_quality = CalVideoQuality(sreenWindowWidth, screenWindowHeight, true); int vbr_max_bitrate = CalVbrMaxKBitRate(sreenWindowWidth, screenWindowHeight); libPublisher.SmartPublisherSetSwVBRMode(publisherHandle, is_enable_vbr, video_quality, vbr_max_bitrate); } //音頻相關可以參考SmartPublisher工程 /* if (!is_speex) { // set AAC encoder libPublisher.SmartPublisherSetAudioCodecType(publisherHandle, 1); } else { // set Speex encoder libPublisher.SmartPublisherSetAudioCodecType(publisherHandle, 2); libPublisher.SmartPublisherSetSpeexEncoderQuality(publisherHandle, 8); } libPublisher.SmartPublisherSetNoiseSuppression(publisherHandle, is_noise_suppression ? 1 : 0); libPublisher.SmartPublisherSetAGC(publisherHandle, is_agc ? 1 : 0); */ // libPublisher.SmartPublisherSetClippingMode(publisherHandle, 0); //libPublisher.SmartPublisherSetSWVideoEncoderProfile(publisherHandle, sw_video_encoder_profile); //libPublisher.SmartPublisherSetSWVideoEncoderSpeed(publisherHandle, sw_video_encoder_speed); // libPublisher.SetRtmpPublishingType(publisherHandle, 0); libPublisher.SmartPublisherSetFPS(publisherHandle, 18); //幀率可調 libPublisher.SmartPublisherSetGopInterval(publisherHandle, 18*3); //libPublisher.SmartPublisherSetSWVideoBitRate(publisherHandle, 1200, 2400); //針對軟編碼有效，一般最大碼率是平均碼率的二倍 libPublisher.SmartPublisherSetSWVideoEncoderSpeed(publisherHandle, 3); //libPublisher.SmartPublisherSaveImageFlag(publisherHandle, 1); }

初始化、參數設置后，設置RTMP推送的URL，並調用SartPublisher()接口，開始推送：

        //如果同時推送和錄像，設置一次就可以 InitAndSetConfig(); if ( publisherHandle == 0 ) { stopScreenCapture(); return; } if(push_type == PUSH_TYPE_RTMP) { String publishURL = intent.getStringExtra("PUBLISHURL"); Log.i(TAG, "publishURL: " + publishURL); if (libPublisher.SmartPublisherSetURL(publisherHandle, publishURL) != 0) { stopScreenCapture(); Log.e(TAG, "Failed to set publish stream URL.."); if (publisherHandle != 0) { if (libPublisher != null) { libPublisher.SmartPublisherClose(publisherHandle); publisherHandle = 0; } } return; } } //啟動傳遞數據線程 post_data_thread = new Thread(new DataRunnable()); Log.i(TAG, "new post_data_thread.."); is_post_data_thread_alive = true; post_data_thread.start();

  int startRet = libPublisher.SmartPublisherStartPublisher(publisherHandle); if (startRet != 0) { isPushingRtmp = false; Log.e(TAG, "Failed to start push rtmp stream.."); return; } //如果同時推送和錄像，Audio啟動一次就可以了 CheckInitAudioRecorder();

開始推送后，傳遞數據到底層SDK：

    public class DataRunnable implements Runnable{ private final static String TAG = "DataRunnable==> "; @Override public void run() { // TODO Auto-generated method stub Log.i(TAG, "post data thread is running.."); ByteBuffer last_buffer = null; Image last_image = null; long last_post_time = System.currentTimeMillis(); while (is_post_data_thread_alive) { boolean is_skip = false; /* synchronized (data_list_lock) { if ( data_list.isEmpty()) { if((System.currentTimeMillis() - last_post_time) > frame_added_interval_setting) { if(last_buffer != null) { Log.i(TAG, "補幀中.."); } else { is_skip = true; } } else { is_skip = true; } } else { last_buffer = data_list.get(0); data_list.remove(0); } } */ Image new_image = popImage(); if ( new_image == null ) { if((System.currentTimeMillis() - last_post_time) > frame_added_interval_setting) { if(last_image != null) { Log.i(TAG, "補幀中.."); } else { is_skip = true; } } else { is_skip = true; } } else { if ( last_image != null ) { last_image.close(); } last_image = new_image; } if( is_skip ) { // Log.i("OnScreenImage", "is_skip"); try { Thread.sleep(5); //休眠5ms } catch (InterruptedException e) { e.printStackTrace(); } } else { //if( last_buffer != null && publisherHandle != 0 && (isPushing || isRecording || isRTSPPublisherRunning) ) if( last_image != null && publisherHandle != 0 && (isPushingRtmp || isRecording || isRTSPPublisherRunning) ) { long post_begin_time = System.currentTimeMillis(); final Image.Plane[] planes = last_image.getPlanes(); if ( planes != null && planes.length > 0 ) { libPublisher.SmartPublisherOnCaptureVideoRGBAData(publisherHandle, planes[0].getBuffer(), planes[0].getRowStride(), last_image.getWidth(), last_image.getHeight()); } last_post_time = System.currentTimeMillis(); long post_cost_time = last_post_time - post_begin_time; if ( post_cost_time >=0 && post_cost_time < 10 ) { try { Thread.sleep(10-post_cost_time); } catch (InterruptedException e) { e.printStackTrace(); } } /* libPublisher.SmartPublisherOnCaptureVideoRGBAData(publisherHandle, last_buffer, row_stride_, width_, height_); */ /* //實際裁剪比例，可酌情自行調整 int left = 100; int cliped_left = 0; int top = 0; int cliped_top = 0; int cliped_width = width_; int cliped_height = height_; if(scale_rate == SCALE_RATE_HALF) { cliped_left = left / 2; cliped_top = top / 2; //寬度裁剪后，展示3/4比例 cliped_width = (width_ *3)/4; //高度不做裁剪 cliped_height = height_; } else if(scale_rate == SCALE_RATE_TWO_FIFTHS) { cliped_left = left * 2 / 5; cliped_top = top * 2 / 5; //寬度裁剪后，展示3/4比例 cliped_width = (width_ *3)/4; //高度不做裁剪 cliped_height = height_; } if(cliped_width % 2 != 0) { cliped_width = cliped_width + 1; } if(cliped_height % 2 != 0) { cliped_height = cliped_height + 1; } if ( (cliped_left + cliped_width) > width_) { Log.e(TAG, " invalid cliped region settings, cliped_left: " + cliped_left + " cliped_width:" + cliped_width + " width:" + width_); return; } if ( (cliped_top + cliped_height) > height_) { Log.e(TAG, "invalid cliped region settings, cliped_top: " + cliped_top + " cliped_height:" + cliped_height + " height:" + height_); return; } //Log.i(TAG, " clipLeft: " + cliped_left + " clipTop: " + cliped_top + " clipWidth: " + cliped_width + " clipHeight: " + cliped_height); libPublisher.SmartPublisherOnCaptureVideoClipedRGBAData(publisherHandle, last_buffer, row_stride_, width_, height_, cliped_left, cliped_top, cliped_width, cliped_height ); */ // Log.i(TAG, "post data: " + last_post_time + " cost:" + post_cost_time); } else { try { Thread.sleep(10); } catch (InterruptedException e) { e.printStackTrace(); } } } } if ( last_image != null) { last_image.close(); last_image = null; } } } 

關閉采集推送：

    public void onDestroy() { // TODO Auto-generated method stub Log.i(TAG, "Service stopped.."); stopScreenCapture(); clearAllImages(); if( is_post_data_thread_alive && post_data_thread != null ) { Log.i(TAG, "onDestroy close post_data_thread++"); is_post_data_thread_alive = false; try { post_data_thread.join(); } catch (InterruptedException e) { e.printStackTrace(); } post_data_thread = null; Log.i(TAG, "onDestroy post_data_thread closed--"); } if (isPushingRtmp || isRecording || isRTSPPublisherRunning) { if (audioRecord_ != null) { Log.i(TAG, "surfaceDestroyed, call StopRecording.."); audioRecord_.Stop(); if (audioRecordCallback_ != null) { audioRecord_.RemoveCallback(audioRecordCallback_); audioRecordCallback_ = null; } audioRecord_ = null; } stopPush(); isPushingRtmp = false; stopRecorder(); isRecording = false; stopRtspPublisher(); isRTSPPublisherRunning = false; stopRtspService(); isRTSPServiceRunning = false; if (publisherHandle != 0) { if (libPublisher != null) { libPublisher.SmartPublisherClose(publisherHandle); publisherHandle = 0; } } } libPublisher.UnInitRtspServer(); super.onDestroy(); }

以上就是Android平台數據采集、編碼並推送的大概流程，感興趣的開發者可參考下。