/**
 * OpenCV video recording tool.
 *
 * Based on CvBase, see which.
 *
 * @author vona
 **/

#include "cvbase.hpp"

#include <iostream>

using namespace std;

/** Extends base class to record all captured frames to a file. **/
class CvRecord : public CvBase {

  protected:

  /** The video writer. **/
  CvVideoWriter *vw;

  /** Output filename. **/
  const char *outfile;

  /** Output codec. **/
  int fourcc;

  /** Output frames per second. **/
  double outFPS;

  /** Adds command line help. **/
  virtual void cmdHelpExt() {
    cout<<"  where R is outfile [outFPS] [fourcc]"<<endl;
  }

  /** Adds command line parameter help. **/
  virtual std::string cmdHelpExtParams() { return "R "; }

  /**
   * Creates video writer on first frame.
   *
   * Saves each frame to the video.
   **/
  virtual IplImage *process(IplImage *frame) { 

    double startMS;

    if ((frameN == 0) && (vw == 0)) {
      cout<<"creating video writer"<<endl;
      vw = cvCreateVideoWriter(outfile, fourcc, outFPS,
                               cvSize(frame->width, frame->height));
      if (vw == 0)
        cerr<<"W: error creating video writer"<<endl;
    }

    if (!paused && (vw != 0)) {
      startMS = nowMS();
      if (!cvWriteFrame(vw, frame))
        cerr<<"W: error writing frame "<<frameN<<" to video file"<<endl;
      if (dbg) cout<<"wrote frame to video file ("
                   <<(nowMS()-startMS)<<"ms)"<<endl;
    }

    return frame;
  }

  public:

  /** Default output codec. **/
  static const int DEF_FOURCC;

  /** Consructor initializes members. **/
  CvRecord() : CvBase("cvrecord")
  { vw = 0; outfile = 0; fourcc = DEF_FOURCC; outFPS = -1; }

  /** Destructor releases video writer. **/
  virtual ~CvRecord() { if (vw != 0) cvReleaseVideoWriter(&vw); }

  /** Parses base class plus extra args. **/
  virtual int initExt(int argc, char *argv[], int ate) {

    //must have at least one extra arg (plus the very first entry of argv which
    //was the invoked program name)
    if (argc < ate+2) { cmdHelp(); exit(-1); }
    outfile = argv[++ate];

    //if there is another arg, and it parses as an int, set outFPS
    //else default outFPS to maxFPS
    outFPS = maxFPS;
    if ((argc > ate+1) && !(istringstream(argv[ate+1])>>outFPS).fail()) ate++;

    //if there is yet another arg, and it is a string of four characters, parse
    //it as a fourcc
    fourcc = DEF_FOURCC;
    if (argc > ate+1) {
      char *s = argv[++ate];
      if (strlen(s) == 4) fourcc = CV_FOURCC(s[0], s[1], s[2], s[3]);
    }

    cout<<"writing video to \""<<outfile
        <<"\", fourcc 0x"<<hex<<fourcc<<dec<<" ("
        <<(char)((fourcc>>0*8)&0xff)
        <<(char)((fourcc>>1*8)&0xff)
        <<(char)((fourcc>>2*8)&0xff)
        <<(char)((fourcc>>3*8)&0xff)
        <<"), "<<outFPS<<" FPS"<<endl;

    return ate;
  }
};

const int CvRecord::DEF_FOURCC = CV_FOURCC('M','J','P','G');

/** Program entry point. **/
int main(int argc, char *argv[]) {
  CvRecord r;
  r.init(argc, argv);
  r.mainLoop();
}