openFrameworks ofxSequenceExport.h / Multi Thread Sequence Exporter.

Multi Thread Sequence Exporter

#include "ofMain.h"
#include "ofxSequenceExport.h"

const unsigned int WIDTH = 1920;
const unsigned int HEIGHT = 1080;

class ofApp : public ofBaseApp
{
    ofxSequenceExport expo;
    ofFbo fbo;
    
public:
    
    ofApp(){}
    
    void exit() {
        expo.close();
    }

    void setup()
    {
        ofSetFrameRate(60);
        ofBackground(0);
        
        fbo.allocate( WIDTH, HEIGHT, GL_RGBA );
        expo.setup( "sequence/test/", "png" );
    }
    
    void update()
    {
        fbo.begin();
        {
            ofClear(0);
            
            // drawing
            {
                for (int i=0; i<100; i++) {
                    ofSetColor(ofRandom(255), ofRandom(255), ofRandom(255));
                    ofCircle(ofRandom(WIDTH), ofRandom(HEIGHT), ofRandom(50));
                }
            }
        }
        fbo.end();
        
        if(expo.running()) expo.addQue( &fbo );
    }
    
    void draw()
    {
        ofSetColor(255);
        fbo.draw(0,0);
        ofDrawBitmapString(ofToString(ofGetFrameRate()), WIDTH-80, 30);
        ofDrawBitmapString("renderFrame/addFrame  "+ofToString(expo.getRenderFrame())+" / "+ofToString(expo.getAddFrame()),
                           30, 30 );
    }
    
    void keyPressed(int key)
    {
        switch (key)
        {
            case 's':
                if(expo.running()) expo.stop();
                else expo.start();
                break;
        }
    };
};

#include "ofAppGLFWWindow.h"
int main(int argc, const char** argv)
{
    ofAppGLFWWindow window;
    window.setMultiDisplayFullscreen(true);
    window.setNumSamples(4);
    ofSetupOpenGL(&window, WIDTH, HEIGHT, OF_WINDOW);
    ofRunApp(new ofApp);
    return 0;
}

ofxSequenceExport.h

//
//  ofxSequenceExport.h
//  base : https://github.com/atduskgreg/ofxImageSequenceRecorder
//
#pragma once

const unsigned int MULTI_THREAD_NUM = 6;

typedef struct{
    string fName;
    ofPixels pixs;
} QueImg;

class SequenceExport : public ofThread
{
public:
    deque<QueImg> ques;
    int renderFrame = 0;
    
    void close(){ stop(); }
    bool running(){ return isThreadRunning(); }
    
    void start() {
        renderFrame = 0;
        this->startThread(false,true);   // blocking, verbose
    }
    void stop() {
        this->stopThread();
    }
    
    void threadedFunction()
    {
        while(isThreadRunning()) {
            if(!ques.empty())
            {
                QueImg i = ques.front();
                ofSaveImage( i.pixs, i.fName);
                ques.pop_front();
                
                if( lock() ){
                    renderFrame++;
                    unlock();
                }
            }
        }
    }
};

class ofxSequenceExport
{
    SequenceExport expos[ MULTI_THREAD_NUM ];

    string outpath,format;
    int addFrame, renderFrame;
    bool isThreadRunning = false;
    
public:
    
    void setup( string outpath_, string format_ ) {
        addFrame = 0;
        renderFrame = 0;
        outpath = outpath_;
        format = format_;
    }
    
    void close(){
        stop();
    }
    
    void start()
    {
        addFrame = 0;
        renderFrame = 0;
        isThreadRunning = true;
        
        for (int i=0; i<MULTI_THREAD_NUM; i++) {
            expos[i].start();
        }
    }
    void stop(){
        isThreadRunning = false;
        for (int i=0; i<MULTI_THREAD_NUM; i++) {
            expos[i].stop();
        }
    }
    
    void addQue(ofFbo *fbo){
        ofPixels pixs;
        fbo->readToPixels( pixs );
        addQue( pixs );
    }
    
    void addQue(ofPixels pixs)
    {
        assert( outpath.length()>0 );
        assert( format.length()>0 );
        
        char fName[100];
        sprintf(fName,  "%s%.6i.%s" , outpath.c_str(), addFrame, format.c_str() );
        
        QueImg que;
        que.fName = fName;
        que.pixs = pixs;
        expos[ addFrame%MULTI_THREAD_NUM ].ques.push_back( que );
        
        addFrame++;
        getRenderFrame();
    }
    
    int getRenderFrame() {
        renderFrame = 0;
        for (int i=0; i<MULTI_THREAD_NUM; i++) {
            renderFrame += expos[i].renderFrame;
        }
        return renderFrame;
    }
    int getAddFrame() { return addFrame; }
    
    bool running(){ return isThreadRunning; }
};