#ifndef _PASS1RATECTL_HH
#define _PASS1RATECTL_HH

/*  (C) 2006 Andrew Stevens */

/*  This is free software; you can redistribute it
 *  and/or modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version 2 of
 *  the License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 *
 */

#include "ratectl.hh"

/*
    The parts of of the rate-controller's state neededfor save/restore if backing off
    a partial encoding
*/

class LookaheadRCPass1State :  public RateCtlState
{
public:
    virtual ~LookaheadRCPass1State() {}
    virtual RateCtlState *New() const { return new LookaheadRCPass1State; }
    virtual void Set( const RateCtlState &state ) { *this = static_cast<const LookaheadRCPass1State &>(state); }
    virtual const RateCtlState &Get() const { return *this; }
    int target_bits; // target_bits
    int vbuf_fullness;
        int ratectl_vbuf[NUM_PICT_TYPES];

    int per_pict_bits;
    int     fields_in_gop;
    double  field_rate;
    int     fields_per_pict;

    int buffer_variation;
    int64_t bits_transported;
    int64_t bits_used;
    int gop_buffer_correction;


    int frame_overshoot_margin;
    int undershoot_carry;
    double overshoot_gain;

    /*
      actsum - Total activity (sum block variances) in frame
      actcovered - Activity macroblocks so far quantised (used to
      fine tune quantisation to avoid starving highly
      active blocks appearing late in frame...) UNUSED
      avg_act - Current average activity...
    */
    double actsum;
    double actcovered;
    double sum_avg_act;
    double avg_act;
    double avg_var;
    double sum_avg_var;
    double sum_avg_quant;


    int N[NUM_PICT_TYPES];


    int min_d, max_d;
    int min_q, max_q;

    bool fast_tune;
    bool first_gop;
    

    /* X's measure global complexity (Chi! not X!) of frame types.
    * Actually: X = average quantisation * bits allocated in *previous* frame
    * N.b. the choice of measure is *not* arbitrary.  The feedback bit
    * rate control gets horribly messed up if it is *not* proportionate
    * to bit demand i.e. bits used scaled for quantisation.  
    * d's are virtual reciever buffer fullness 
    * r is Rate control feedback gain (in* bits/frame) 
    */
    
    double Xhi[NUM_PICT_TYPES];

    /* The average complexity of frames of the different types is used
     * to predict a reasonable bit-allocation for these types.
     * The AVG_WINDOW set the size of the sliding window for these
     * averages.  Basically I Frames respond very quickly.
     * B / P frames more or less quickly depending on the target number
     * of B frames per P frame.
     */
    double K_AVG_WINDOW[NUM_PICT_TYPES];

    /*
     * 'Typical' sizes of the different types of picture in a GOP - these
     * sizes are needed so that buffer management can compensate for the
     * 'normal' ebb and flow of buffer space in a GOP (low after a big I frame)
     * nearly full at the end after lots of smaller B/P frames.
     *
     */
    int32_t pict_base_bits[NUM_PICT_TYPES];
    bool first_encountered[NUM_PICT_TYPES];


    // Some statistics for measuring if things are going well.
    double sum_size[NUM_PICT_TYPES];
    int pict_count[NUM_PICT_TYPES];

};


class LookaheadRCPass1 :  public Pass1RateCtl,  public LookaheadRCPass1State
{
public:
    LookaheadRCPass1( EncoderParams &encoder );
    virtual void Init() ;

    virtual void GopSetup( int nb, int np );
    virtual void PictUpdate (Picture &picture, int &padding_needed );


    virtual int  MacroBlockQuant( const MacroBlock &mb);
    virtual int  InitialMacroBlockQuant();


    double SumAvgActivity()  { return sum_avg_act; }
protected:
    virtual int  TargetPictureEncodingSize();

    virtual void InitSeq( );
    virtual void InitGOP( ) ;
    virtual void InitPict( Picture &picture );

private:

    double  cur_base_Q;       // Current base quantisation (before adjustments
                              // for relative macroblock activity
    int     cur_mquant;       // Current macroblock quantisation
    int     mquant_change_ctr;


    double  sum_base_Q;       // Accumulates base quantisations encoding
    int     sum_actual_Q;     // Accumulates actual quantisation

    // inverse feedback gain: its in weird units 
    // The quantisation is porportionate to the
    // buffer bit overshoot (virtual buffer fullness)
    // *divided* by fb_gain  A 
    int32_t fb_gain;        
    


    // VBV calculation data
    double picture_delay;
    double next_ip_delay; /* due to frame reordering delay */
    double decoding_time;

};



/* 
 * Local variables:
 *  c-file-style: "stroustrup"
 *  tab-width: 4
 *  indent-tabs-mode: nil
 * End:
 */
#endif
