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      1 /*
      2  * Copyright 2013 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef SCREENRECORD_OVERLAY_H
     18 #define SCREENRECORD_OVERLAY_H
     19 
     20 #include "Program.h"
     21 #include "TextRenderer.h"
     22 #include "EglWindow.h"
     23 
     24 #include <gui/BufferQueue.h>
     25 #include <gui/GLConsumer.h>
     26 #include <utils/Thread.h>
     27 
     28 #include <EGL/egl.h>
     29 
     30 namespace android {
     31 
     32 /*
     33  * Overlay "filter".  This sits between the virtual display and the video
     34  * encoder.
     35  *
     36  * Most functions run on a thread created by start().
     37  */
     38 class Overlay : public GLConsumer::FrameAvailableListener, Thread {
     39 public:
     40     Overlay() : Thread(false),
     41         mThreadResult(UNKNOWN_ERROR),
     42         mState(UNINITIALIZED),
     43         mFrameAvailable(false),
     44         mExtTextureName(0),
     45         mStartMonotonicNsecs(0),
     46         mStartRealtimeNsecs(0),
     47         mLastFrameNumber(-1),
     48         mTotalDroppedFrames(0)
     49         {}
     50 
     51     // Creates a thread that performs the overlay.  Pass in the surface that
     52     // output will be sent to.
     53     //
     54     // This creates a dedicated thread for processing frames.
     55     //
     56     // Returns a reference to the producer side of a new BufferQueue that will
     57     // be used by the virtual display.
     58     status_t start(const sp<IGraphicBufferProducer>& outputSurface,
     59             sp<IGraphicBufferProducer>* pBufferProducer);
     60 
     61     // Stops the thread and releases resources.  It's okay to call this even
     62     // if start() was never called.
     63     status_t stop();
     64 
     65     // This creates an EGL context and window surface, draws some informative
     66     // text on it, swaps the buffer, and then tears the whole thing down.
     67     static status_t drawInfoPage(const sp<IGraphicBufferProducer>& outputSurface);
     68 
     69 private:
     70     Overlay(const Overlay&);
     71     Overlay& operator=(const Overlay&);
     72 
     73     // Destruction via RefBase.
     74     virtual ~Overlay() { assert(mState == UNINITIALIZED || mState == STOPPED); }
     75 
     76     // Draw the initial info screen.
     77     static void doDrawInfoPage(const EglWindow& window,
     78             const Program& texRender, TextRenderer& textRenderer);
     79 
     80     // (overrides GLConsumer::FrameAvailableListener method)
     81     virtual void onFrameAvailable(const BufferItem& item);
     82 
     83     // (overrides Thread method)
     84     virtual bool threadLoop();
     85 
     86     // One-time setup (essentially object construction on the overlay thread).
     87     status_t setup_l();
     88 
     89     // Release all resources held.
     90     void release_l();
     91 
     92     // Release EGL display, context, surface.
     93     void eglRelease_l();
     94 
     95     // Process a frame received from the virtual display.
     96     void processFrame_l();
     97 
     98     // Convert a monotonic time stamp into a string with the current time.
     99     void getTimeString_l(nsecs_t monotonicNsec, char* buf, size_t bufLen);
    100 
    101     // Guards all fields below.
    102     Mutex mMutex;
    103 
    104     // Initialization gate.
    105     Condition mStartCond;
    106 
    107     // Thread status, mostly useful during startup.
    108     status_t mThreadResult;
    109 
    110     // Overlay thread state.  States advance from left to right; object may
    111     // not be restarted.
    112     enum { UNINITIALIZED, INIT, RUNNING, STOPPING, STOPPED } mState;
    113 
    114     // Event notification.  Overlay thread sleeps on this until a frame
    115     // arrives or it's time to shut down.
    116     Condition mEventCond;
    117 
    118     // Set by the FrameAvailableListener callback.
    119     bool mFrameAvailable;
    120 
    121     // The surface we send our output to, i.e. the video encoder's input
    122     // surface.
    123     sp<IGraphicBufferProducer> mOutputSurface;
    124 
    125     // Producer side of queue, passed into the virtual display.
    126     // The consumer end feeds into our GLConsumer.
    127     sp<IGraphicBufferProducer> mProducer;
    128 
    129     // This receives frames from the virtual display and makes them available
    130     // as an external texture.
    131     sp<GLConsumer> mGlConsumer;
    132 
    133     // EGL display / context / surface.
    134     EglWindow mEglWindow;
    135 
    136     // GL rendering support.
    137     Program mExtTexProgram;
    138     Program mTexProgram;
    139 
    140     // Text rendering.
    141     TextRenderer mTextRenderer;
    142 
    143     // External texture, updated by GLConsumer.
    144     GLuint mExtTextureName;
    145 
    146     // Start time, used to map monotonic to wall-clock time.
    147     nsecs_t mStartMonotonicNsecs;
    148     nsecs_t mStartRealtimeNsecs;
    149 
    150     // Used for tracking dropped frames.
    151     nsecs_t mLastFrameNumber;
    152     size_t mTotalDroppedFrames;
    153 
    154     static const char* kPropertyNames[];
    155 };
    156 
    157 }; // namespace android
    158 
    159 #endif /*SCREENRECORD_OVERLAY_H*/
    160