about summary refs log tree commit diff
path: root/converter/ppm/ppmtompeg/rate.c
blob: c775e055ab18e44038cd92f062e09116832c84d7 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
/*============================================================================*
 * rate.c								      *
 *									      * 
 *	Procedures concerned with rate control                                *
 *									      *
 * EXPORTED PROCEDURES:							      *
 *      initRatecontrol()                                                     *
 *      targetRateControl()                                                   *
 *      updateRateControl()                                                   *
 *      MB_RateOut()                                                          *
 *      needQScaleChange()                                                    *
 *      incNumBlocks()                                                        *
 *      incQuant()                                                            *
 *	incMacroBlockBits()                                                   *
 *      setPictureRate()                                                      *
 *      setBitRate()                                                          *
 *      getBitRate()                                                          *
 *      setBufferSize()                                                       *
 *      getBufferSize()                                                       *
 *                                                                            *
 * NOTES:                                                                     *
 *	Naming conventions follow those of MPEG-2 draft algorithm (chap. 10)  *
 *============================================================================*/


/*
 * Copyright (c) 1995 The Regents of the University of California.
 * All rights reserved.
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose, without fee, and without written agreement is
 * hereby granted, provided that the above copyright notice and the following
 * two paragraphs appear in all copies of this software.
 *
 * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY FOR
 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
 * OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF THE UNIVERSITY OF
 * CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
 * ON AN "AS IS" BASIS, AND THE UNIVERSITY OF CALIFORNIA HAS NO OBLIGATION TO
 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
 */

/*==============*
 * HEADER FILES *
 *==============*/

#include <assert.h>
#include <sys/types.h>

#include "ppm.h"
#include "nstring.h"

#include "all.h"
#include "mtypes.h"
#include "bitio.h"
#include "frames.h"
#include "prototypes.h"
#include "param.h"
#include "mheaders.h"
#include "fsize.h"
#include "postdct.h"
#include "mpeg.h"
#include "parallel.h"
#include "dct.h"
#include "rate.h"


/*==================*
 * GLOBAL VARIABLES *
 *==================*/

#define MAX_BIT_RATE 104857600		/* 18 digit number in units of 400 */
#define MAX_BUFFER_SIZE 16760832        /* 10 digit number in units of 16k */
#define DEFAULT_BUFFER_SIZE 327680      /* maximun for "constrained" bitstream */
#define DEFAULT_VBV_FULLNESS 3          /* wait till 1/3 full */
#define DEFAULT_PICT_RATE_CODE 5        /* code for 30 Frames/sec */
#define DEFAULT_PICT_RATE 30            /* 30 frames per second */
#define MAX_VBV_DELAY 32768             /* 16 digits */


/*	  Variables from Parameter File */

static int	RateControlMode = VARIABLE_RATE;
static int32 buffer_size = DEFAULT_BUFFER_SIZE;
static int32 bit_rate = -1;

static bool wantVbvUnderflowWarning;
static bool wantVbvOverflowWarning;

/*   Variables for the VBV buffer defined in MPEG specs */
static unsigned int VBV_remainingDelay; 
    /* delay in units of 1/90000 seconds */
static int32 VBV_buffer = 0;	  /* fullness of the theoretical VBV buffer */
static int32 bufferFillRate = 0;    /* constant rate at which buffer filled */
static int32 frameDelayIncrement = 0;	/* number of "delay" units/Frame */

/*  Global complexity measure variables */
static int Xi, Xp, Xb;  /*  Global complexity measure  */

static int Si, Sp, Sb;  /*  Total # bits for last pict of type (Overhead?) */

static float Qi, Qp, Qb; /* avg quantizaton for last picture of type  */
     
/*  Target bit allocations for each type of picture*/
int Ti, Tp, Tb;

int current_Tx;	/* allocation for current frame */

/*  Count of number of pictures of each type remaining */
int GOP_X;
int GOP_I;
int GOP_P;
int GOP_B;

int Nx = 0;
int Ni = 0;
int Np = 0;
int Nb = 0;

/*   Counters used while encoding frames   */

int rc_numBlocks = 0;
int rc_totalQuant = 0;
int rc_bitsThisMB;
int rc_totalMBBits;
int rc_totalFrameBits;
int rc_totalOverheadBits = 0;


/*	Want to print out Macroblock info every Nth MB */
int RC_MB_SAMPLE_RATE = 0;

static float Ki = .7;
static float Kp = 1;
static float Kb = 1.4;
static int rc_R;
static int rc_G;

/*   Rate Control variables   */

/*   Virtual buffers for each frame type */
static int d0_i;   /* Initial fullnesses */
static int d0_p;
static int d0_b;

static int lastFrameVirtBuf;   /* fullness after last frame of this type */
static int currentVirtBuf;     /* fullness during current encoding*/

static int MB_cnt = -1;	       /* Number of MB's in picture */

static int rc_Q;               /* reference quantization parameter */

static int reactionParameter;  /*  Reaction parameter */

/*	Adaptive Quantization variables */
static int act_j;              /*  spatial activity measure */
static float N_act;            /*  Normalized spacial activity */
static int avg_act;	   /*  average activity value in last picture encoded */
static int total_act_j;	       /*  Sum of activity values in current frame */

static int var_sblk;	       /* sub-block activity */
static int P_mean;	       /* Mean value of pixels in 8x8 sub-block */

static int mquant;	       /* Raw Quantization value */
static int Qscale;	       /* Clipped, truncated quantization value */



/*  Output-related variables */
#ifdef RC_STATS_FILE
static FILE *RC_FILE;
#endif

static const char * const Frame_header1 = 
"  Fm         #     Bit      GOP                    V                ";
static const char * const Frame_header2 = 
"   #  type   MBs   Alloc    left  Ni Np Nb  N_act  buff   Q_rc Qscale";
static const char * const Frame_header3 = 
"----     -  ----  ------ -------  -- -- --  -----  ------ ----   ----";
static const char * const Frame_trailer1 = 
"                      avg          virt     %    GOP      %     VBV";
static const char * const Frame_trailer2 = 
"    Sx    Qx      Xx  act N_act  buffer alloc    left  left     buf  delay";
static const char * const Frame_trailer3 = 
"------ --.-- -------  --- --.-- -------   --- -------   --- ------- ------";

static const char * const MB_header1 = 
"MB#  #bits  Q mqt     Dj  Q_j   actj  N_act  totbits b/MB %alloc %done";
static const char * const MB_header2 = 
"---  ----- -- --- ------  ---  -----  --.--   ------ ----    ---   ---";

static char rc_buffer[101];

/*	EXTERNAL Variables  */
extern char *framePattern;
extern int framePatternLen;


/*===============================*
 * INTERNAL PROCEDURE prototypes *
 *===============================*/

int initGOPRateControl (void);
int determineMBCount (void);
void checkBufferFullness (int count);
void checkSpatialActivity (Block blk0, Block blk1, Block blk2, Block blk3);
void incNumBlocks (int num);
void calculateVBVDelay (int num);
int BlockExperiments  (int16 *OrigBlock, int16 *NewBlock, int control);
     
     

static void
analyzePattern(const char *  const framePattern,
               int           const framePatternLen,
               int *         const gop_xP,
               int *         const gop_iP,
               int *         const gop_pP,
               int *         const gop_bP,
               const char ** const errorP) {

    unsigned int i;

    /*  Initialize Pattern info */
    *gop_xP = framePatternLen;    

    for (i = 0, *gop_iP = 0, *gop_pP = 0, *gop_bP = 0, *errorP = NULL;
         i < framePatternLen && !*errorP; 
         ++i) {
        switch(framePattern[i]) {
        case 'i': ++*gop_iP; break;
        case 'p': ++*gop_pP; break;
        case 'b': ++*gop_bP; break;
        default:
            pm_asprintf(errorP, "Bad pattern - not composed of i, p, and b");
        }
    }
    assert(*gop_xP == *gop_iP + *gop_pP + *gop_bP);
}
  


/*===========================================================================*
 *
 * initRateControl
 *
 *	initialize the allocation parameters.
 *
 * RETURNS:	nothing
 *
 * SIDE EFFECTS:   many global variables 
 *
 * NOTES:  Get rid of the redundant pattern stuff!!
 *===========================================================================*/
int
initRateControl(bool const wantUnderflowWarning,
                bool const wantOverflowWarning) {
    int result;
    const char * error;

    wantVbvUnderflowWarning = wantUnderflowWarning;
    wantVbvOverflowWarning  = wantOverflowWarning;

    DBG_PRINT(("Initializing Allocation Data\n"));
  
#ifdef RC_STATS_FILE
    RC_FILE = fopen("RC_STATS_FILE", "w");
    if ( RC_FILE  == NULL) {
        DBG_PRINT(("Open of RC file failed, using stderr\n"));
        RC_FILE = stderr;
        fprintf(RC_FILE, "Open of RC file failed, using stderr\n");
        fflush(RC_FILE);
    }
#endif

    VBV_remainingDelay = 0;
  
    analyzePattern(framePattern, framePatternLen,
                   &GOP_X, &GOP_I, &GOP_P, &GOP_B, &error);

    if (error) {
        pm_message("Unable to set up rate control.  Switching to variable.  "
                   "%s", error);
        pm_strfree(error);
        RateControlMode = VARIABLE_RATE;
        return -1;
    }


    /* Initializing GOP bit allocation */	
    rc_R = 0;
    rc_G = (bit_rate * GOP_X/frameRateRounded);
  
    /*   Initialize the "global complexity measures" */
    Xi = (160 * bit_rate/115);
    Xp = (60 * bit_rate/115);
    Xb = (42 * bit_rate/115);
  
    /*   Initialize MB counters */
    rc_totalMBBits= rc_bitsThisMB= rc_totalFrameBits=rc_totalOverheadBits = 0;
    rc_numBlocks = rc_totalQuant = 0;
  
    /*   init virtual buffers  */
    reactionParameter = (2 * bit_rate / frameRateRounded);
    d0_i = (10 * reactionParameter / 31);
    d0_p = (Kp * d0_i);
    d0_b = (Kb * d0_i);
  
    lastFrameVirtBuf = d0_i;	/*  start with I Frame */
    rc_Q = lastFrameVirtBuf  * 31 / reactionParameter;
  
    /*   init spatial activity measures */
    avg_act = 400;		/* Suggested initial value */
    N_act = 1;
  
    mquant = rc_Q * N_act;
  
    frameDelayIncrement = (90000 / frameRateRounded);
        /* num of "delay" units per frame */
    bufferFillRate = bit_rate / frameRateRounded; 
        /* VBV buf fills at constant rate */
    VBV_buffer = buffer_size;
    DBG_PRINT(("VBV- delay: %d, fill rate: %d, delay/Frame: %d units, "
               "buffer size: %d\n",
               VBV_remainginDelay, bufferFillRate, frameDelayIncrement, 
               buffer_size));
  
    result = initGOPRateControl();
  
    return result;
}

/*===========================================================================*
 *
 * initGOPRateControl
 *
 *		(re)-initialize the RC for the a new Group of Pictures.
 *	New bit allocation, but carry over complexity measures.
 *
 * RETURNS:	nothing
 *
 * SIDE EFFECTS:   many global variables 
 *
 *===========================================================================*/
int
initGOPRateControl()
{
    DBG_PRINT(("Initializing new GOP\n"));
  
    Nx = GOP_X;
    Ni = GOP_I;
    Np = GOP_P;
    Nb = GOP_B;
  
    rc_R += rc_G;
  
    DBG_PRINT(("bufsize: %d, bitrate: %d, pictrate: %d, GOP bits: %d\n",
               buffer_size, bit_rate, frameRateRounded, rc_R));
    DBG_PRINT(("Xi: %d, Xp: %d, Xb: %d Nx: %d, Ni: %d, Np: %d, Nb: %d\n",
               Xi, Xp, Xb, Nx,Ni,Np,Nb));
    DBG_PRINT(("d0_i: %d, d0_p: %d, d0_b: %d, avg_act: %d, rc_Q: %d, "
               "mquant: %d\n",
               d0_i, d0_p, d0_b, avg_act, rc_Q, mquant));
    return 1;
}



/*===========================================================================*
 *
 * targetRateControl
 *
 *      Determine the target allocation for given picture type, initiates
 *  variables for rate control process.
 *
 * RETURNS:     nothing.
 *
 * SIDE EFFECTS:   many global variables
 *
 *===========================================================================*/
void
targetRateControl(MpegFrame * const frame) {

    float temp1, minimumBits;
    float tempX, tempY, tempZ;
    int result;
    int frameType;
    const char *strPtr;
  
    minimumBits = (bit_rate / (8 * frameRateRounded));
  
    /*   Check if new GOP */
    if (Nx == 0) {
        initGOPRateControl();
    }
  
    if (MB_cnt < 0) {MB_cnt = determineMBCount();}
  
    switch (frame->type) {
    case TYPE_IFRAME:
        frameType = 'I';
    
        tempX = ( (Np * Ki * Xp) / (Xi * Kp) );
        tempY = ( (Nb * Ki * Xb) / (Xi*Kb) );
        tempZ = Ni + tempX + tempY;
        temp1 = (rc_R / tempZ);
        result = (int) (temp1 > minimumBits ? temp1 :  minimumBits);
        current_Tx = Ti = result;
        lastFrameVirtBuf = d0_i;
        break;
    
    case TYPE_PFRAME:
        frameType = 'P';
        tempX =  ( (Ni * Kp * Xi) / (Ki * Xp) );
        tempY =  ( (Nb * Kp * Xb) / (Kb * Xp) );
        tempZ = Np + tempX + tempY;
        temp1 = (rc_R/ tempZ);
        result = (int) (temp1 > minimumBits ? temp1 :  minimumBits);
        current_Tx = Tp = result;
        lastFrameVirtBuf = d0_p;
        break;
    
    case TYPE_BFRAME:
        frameType = 'B';
        tempX =  ( (Ni * Kb * Xi) / (Ki * Xb) );
        tempY =  ( (Np * Kb * Xp) / (Kp * Xb) );
        tempZ = Nb + tempX + tempY;
        temp1 = (rc_R/ tempZ);
        result = (int) (temp1 > minimumBits ? temp1 :  minimumBits);
        current_Tx = Tb = result;
        lastFrameVirtBuf = d0_b;
        break;
    
    default:
        frameType = 'X';
    }
  
    N_act = 1;
    rc_Q = lastFrameVirtBuf  * 31 / reactionParameter;
    mquant = rc_Q * N_act;
    Qscale = (mquant > 31 ? 31 : mquant);
    Qscale = (Qscale < 1 ? 1 : Qscale);
  
    /*   Print headers for Frame info */
    strPtr = Frame_header1;
    DBG_PRINT(("%s\n",strPtr));
    strPtr = Frame_header2;
    DBG_PRINT(("%s\n",strPtr));
    strPtr = Frame_header3;
    DBG_PRINT(("%s\n",strPtr));
  
    /*   Print Frame info */
    sprintf(rc_buffer, "%4d     %1c  %4d  %6d %7d  "
            "%2d %2d %2d   %2.2f  %6d %4d    %3d",
            frame->id,frameType,MB_cnt,current_Tx,rc_R,Ni,Np,Nb, 
            N_act, lastFrameVirtBuf, rc_Q, Qscale);
  
#ifdef RC_STATS_FILE
    fprintf(RC_FILE,"%s\n", rc_buffer);
    fflush(RC_FILE);
#endif
    DBG_PRINT(("%s\n",rc_buffer));
  
    /*  Print headers for Macroblock info */
    if (RC_MB_SAMPLE_RATE) {
        strPtr = MB_header1;
        DBG_PRINT(("%s\n",strPtr));
        strPtr = MB_header2;
        DBG_PRINT(("%s\n",strPtr));
    }
}




static void 
updateVBVBuffer(int const frameBits) {
/*----------------------------------------------------------------------------
  Update the VBV buffer after each frame.  This theoretical buffer is
  being filled at constant rate 'bufferFillRate' from an mpeg stream.
  It is emptied as each frame is grabbed by the decoder.  Exception is
  that the decoder will wait until the "delay" is over.

  We mark the passing of one unit of time, in which 'frameBits' bits of
  mpeg data were grabbed from the buffer by the decoder.
-----------------------------------------------------------------------------*/
    if (VBV_remainingDelay)
        VBV_remainingDelay -= MIN(frameDelayIncrement, VBV_remainingDelay);
    else
        VBV_buffer -= frameBits;

    VBV_buffer += bufferFillRate;
    if (VBV_buffer < 0 && wantVbvUnderflowWarning)
        pm_message("WARNING - VBV buffer underflow (%d)", VBV_buffer);
    if (VBV_buffer > buffer_size && wantVbvOverflowWarning)
        pm_message("WARNING - VBV buffer overflow (%d > %d)",
                   VBV_buffer, buffer_size);
}



/*===========================================================================*
 *
 * updateRateControl
 *
 *      Update the statistics kept, after end of frame.  Resets
 *  various global variables
 *
 * RETURNS:     nothing
 *
 * SIDE EFFECTS:   many global variables
 *
 *===========================================================================*/
void
updateRateControl(int const type) {
    int totalBits, frameComplexity, pctAllocUsed, pctGOPUsed;
    float avgQuant;
    const char *strPtr;

    totalBits = rc_totalFrameBits;
    avgQuant = ((float) rc_totalQuant / (float) rc_numBlocks);
    frameComplexity = totalBits * avgQuant;
    pctAllocUsed = (totalBits *100 / current_Tx);
    rc_R -= totalBits;
    pctGOPUsed = (rc_R *100/ rc_G);
  
    avg_act = (total_act_j / MB_cnt);
  
    updateVBVBuffer(totalBits);
  
    switch (type) {
    case TYPE_IFRAME:
        Ti = current_Tx;
        d0_i = currentVirtBuf;
        Ni--;
        Si = totalBits;
        Qi = avgQuant;
        Xi = frameComplexity;
        break;
    case TYPE_PFRAME:
        Tp = current_Tx;
        d0_p = currentVirtBuf;
        Np--;
        Sp = totalBits;
        Qp = avgQuant;
        Xp = frameComplexity;
        break;
    case TYPE_BFRAME:
        Tb = current_Tx;
        d0_b = currentVirtBuf;
        Nb--;
        Sb = totalBits;
        Qb = avgQuant;
        Xb = frameComplexity;
        break;
    }
  
  
    /*  Print Frame info */
    strPtr = Frame_trailer1;
    DBG_PRINT(("%s\n",strPtr));
    strPtr = Frame_trailer2;
    DBG_PRINT(("%s\n",strPtr));
    strPtr = Frame_trailer3;
    DBG_PRINT(("%s\n",strPtr));
  
    sprintf(rc_buffer, "%6d  %2.2f  %6d  %3d  %2.2f %7d   "
            "%3d %7d   %3d  %6d %6d",
            totalBits, avgQuant, frameComplexity, avg_act, N_act, 
            currentVirtBuf, pctAllocUsed, rc_R, pctGOPUsed, 
            VBV_buffer, VBV_remainingDelay);
#ifdef RC_STATS_FILE
    fprintf(RC_FILE,"%s\n", rc_buffer);
    fflush(RC_FILE);
#endif
    DBG_PRINT(("%s\n",rc_buffer));
  
    Nx--;
    rc_totalMBBits= rc_bitsThisMB= rc_totalFrameBits=rc_totalOverheadBits = 0;
    rc_numBlocks = rc_totalQuant = total_act_j = currentVirtBuf = 0;
  
    DBG_PRINT(("GOP now has %d bits remaining (%3d%%) for %d frames .. , "
               "Ni= %d, Np= %d, Nb= %d\n", 
               rc_R, (rc_R*100/rc_G), (Ni+Np+Nb), Ni, Np, Nb));
  
}


/*===========================================================================*
 *
 * MB_RateOut
 *
 *      Prints out sampling of MB rate control data.  Every "nth" block
 *	stats are printed, with "n" controlled by global RC_MB_SAMPLE_RATE
 *	(NB. "skipped" blocks do not go through this function and thus do not
 *		show up in the sample )
 *
 * RETURNS:     nothing
 *
 * SIDE EFFECTS:   none
 *
 * NOTES:
 *
 *===========================================================================*/
void
  MB_RateOut(type)
int type;
{
  int totalBits;
  int pctUsed, pctDone;
  int bitsThisMB;
  int bitsPerMB;
  
  bitsThisMB = rc_bitsThisMB;
  totalBits = rc_totalFrameBits;
  bitsPerMB = (totalBits / rc_numBlocks); 
  pctDone = (rc_numBlocks * 100/ MB_cnt); 
  pctUsed = (totalBits *100/current_Tx);
  
  sprintf(rc_buffer, "%3d  %5d %2d %3d %6d  %3d %6d   %2.2f   %6d %4d    %3d   %3d\n",
	  (rc_numBlocks - 1), bitsThisMB, Qscale, mquant, currentVirtBuf, 
	  rc_Q, act_j, N_act, totalBits, bitsPerMB, pctUsed, pctDone);
#ifdef RC_STATS_FILE
  fprintf(RC_FILE, "%s", rc_buffer);
  fflush(RC_FILE);
#endif
  
  if ( (RC_MB_SAMPLE_RATE) && ((rc_numBlocks -1) % RC_MB_SAMPLE_RATE)) {
    DBG_PRINT(("%s\n", rc_buffer));
  } else {
    return;
  }
}



/*===========================================================================*
 *
 * incNumBlocks()
 *
 *
 * RETURNS:   nothing
 *
 * SIDE EFFECTS:  rc_numBlocks
 *
 * NOTES:
 *
 *===========================================================================*/
void incNumBlocks(num)
     int num;
{
  rc_numBlocks += num;
}


/*===========================================================================*
 *
 * incMacroBlockBits()
 *
 *	Increments the number of Macro Block bits and the total of Frame
 *  bits by the number passed.
 *
 * RETURNS:   nothing
 *
 * SIDE EFFECTS:  rc_totalMBBits
 *
 * NOTES:
 *
 *===========================================================================*/
void incMacroBlockBits(num)
     int num;
{
  rc_bitsThisMB = num;
  rc_totalMBBits += num;
  rc_totalFrameBits += num;
}


/*===========================================================================*
 *
 *   	needQScaleChange(current Q scale, 4 luminance blocks)
 *
 *
 * RETURNS:     new Qscale
 *
 * SIDE EFFECTS:   
 *
 *===========================================================================*/
int needQScaleChange(oldQScale, blk0, blk1, blk2, blk3)
     int oldQScale;
     Block blk0;
     Block blk1;
     Block blk2;
     Block blk3;
{
  
  /*   One more MacroBlock seen */
  rc_numBlocks++;		/* this notes each block num in MB */
  
  checkBufferFullness(oldQScale);
  
  checkSpatialActivity(blk0, blk1, blk2, blk3);
  
  mquant = rc_Q * N_act;
  Qscale = (mquant > 31 ? 31 : mquant);
  Qscale = (Qscale < 1 ? 1 : Qscale);
  rc_totalQuant += Qscale;
  
  if (oldQScale == Qscale)
    return -1;
  else
    return Qscale;
}


/*===========================================================================*
 *
 * determineMBCount() 
 *
 *      Determines number of Macro Blocks in frame from the frame sizes
 *	passed.
 *
 * RETURNS:     nothing
 *
 * SIDE EFFECTS:   sets the count passed
 *
 *===========================================================================*/
int
  determineMBCount ()
{
  int y,x;
  
  x = (Fsize_x +15)/16;
  y = (Fsize_y +15)/16;
  return  (x * y);
}



/*===========================================================================*
 *
 * void checkBufferFullness ()
 *
 *      Calculates the fullness of the virtual buffer for each
 *  frame type.  Called before encoding each macro block.  Along
 *  with the normalized spatial activity measure (N_act), it
 *  determine the quantization factor for the next macroblock.
 *
 * RETURNS:     nothing
 *
 * SIDE EFFECTS:   the "currentVirtBuf" variable
 *
 * NOTES:
 *
 *===========================================================================*/
void checkBufferFullness (oldQScale)
     int oldQScale;
{
  int temp;
  
  temp = lastFrameVirtBuf + rc_totalFrameBits;
  temp -=  (current_Tx * rc_numBlocks / MB_cnt);
  currentVirtBuf = temp;
  
  rc_Q = (currentVirtBuf * 31 / reactionParameter);
  return;
}


/*===========================================================================*
 *
 * void checkSpatialActivity()
 *
 *      Calcualtes the spatial activity for the four luminance blocks of the
 *	macroblock.  Along with the normalized reference quantization parameter 
 *  (rc_Q) , it determines the quantization factor for the next macroblock.
 *
 * RETURNS:     nothing
 *
 * SIDE EFFECTS:   the Adaptive quantization variables- act_j, N_act.
 *
 * NOTES:
 *
 *===========================================================================*/
void checkSpatialActivity(blk0, blk1, blk2, blk3)
     Block blk0;
     Block blk1;
     Block blk2;
     Block blk3;
{
  int temp;
  int16 *blkArray[4]; 
  int16 *curBlock;
  int16 *blk_ptr;
  int var[4];
  int i, j;
  
  
  blkArray[0] = (int16 *) blk0;
  blkArray[1] = (int16 *) blk1;
  blkArray[2] = (int16 *) blk2;
  blkArray[3] = (int16 *) blk3;
  
  
  for (i =0; i < 4; i++) {	/* Compute the activity in each block */
    curBlock = blkArray[i];
    blk_ptr = curBlock;
    P_mean = 0;
    /*  Find the mean pixel value */
    for (j=0; j < DCTSIZE_SQ; j ++) {
      P_mean += *(blk_ptr++);
      /*			P_mean += curBlock[j]; 
				if (curBlock[j] != *(blk_ptr++)) {
				printf("ARRAY ERROR: block %d\n", j);
				}
				*/
    }
    P_mean /= DCTSIZE_SQ;
    
    /*  Now find the variance  */
    curBlock = blkArray[i];
    blk_ptr = curBlock;
    var[i] = 0;
    for (j=0; j < DCTSIZE_SQ; j++) {
#ifdef notdef
      if (curBlock[j] != *(blk_ptr++)) {
	printf("ARRAY ERROR: block %d\n", j);
      }
      temp = curBlock[j] - P_mean;
#endif      
      temp = *(blk_ptr++) - P_mean;
      var[i] += (temp * temp);
    }
    var[i] /= DCTSIZE_SQ;
  }
  
  /*  Choose the minimum variance from the 4 blocks and use as the activity */
  var_sblk  = var[0];
  for (i=1; i < 4; i++) {
    var_sblk = (var_sblk < var[i] ? var_sblk : var[i]);
  }
  
  
  act_j = 1 + var_sblk;
  total_act_j += act_j;
  temp = (2 * act_j + avg_act);
  N_act = ( (float) temp / (float) (act_j + 2*avg_act) );
  
  return;
}




/*============================================================================*
 *
 * getRateMode ()
 *
 *      Returns the rate mode- interpreted as either Fixed or Variable
 *
 * RETURNS:     integer
 *
 * SIDE EFFECTS:   none
 *
 *
 *==========================================================================*/
int getRateMode()
{
  return RateControlMode;
}


/*===========================================================================*
 *
 * setBitRate ()
 *
 *      Checks the string parsed from the parameter file.  Verifies
 *  number and sets global values. MPEG standard specifies that bit rate
 *	be rounded up to nearest 400 bits/sec.
 *
 * RETURNS:     nothing
 *
 * SIDE EFFECTS:   global variables
 *
 * NOTES:	Should this be in the 400-bit units used in sequence header?
 *
 *===========================================================================*/
void setBitRate (const char * const charPtr)
{
  int rate, rnd;
  
  rate = atoi(charPtr);
  if (rate > 0) {
    RateControlMode = FIXED_RATE;
  } else {
    printf("Parameter File Error:  invalid BIT_RATE: \"%s\", defaults to Variable ratemode\n",
	   charPtr);
    RateControlMode = VARIABLE_RATE;
    bit_rate = -1;
  }
  rnd = (rate % 400);
  rate += (rnd ? 400 -rnd : 0); /* round UP to nearest 400 bps */
  rate = (rate > MAX_BIT_RATE ? MAX_BIT_RATE : rate);
  bit_rate = rate;
  DBG_PRINT(("Bit rate is: %d\n", bit_rate));
} 



/*===========================================================================*
 *
 * getBitRate ()
 *
 *      Returns the bit rate read from the parameter file.  This is the
 *  real rate in bits per second, not in 400 bit units as is written to
 *  the sequence header.
 *
 * RETURNS:     int (-1 if Variable mode operation)
 *
 * SIDE EFFECTS:   none
 *
 *===========================================================================*/
int getBitRate ()
{
  return bit_rate;
}




/*===========================================================================*
 *
 * setBufferSize ()
 *
 *      Checks the string parsed from the parameter file.  Verifies
 *  number and sets global values.
 *
 * RETURNS:     nothing
 *
 * SIDE EFFECTS:   buffer_size global variable.
 *
 * NOTES:	The global is in bits, NOT the 16kb units used in sequence header
 *
 *===========================================================================*/
void setBufferSize (const char * const charPtr)
{
  int size;
  
  size = atoi(charPtr);
  size = (size > MAX_BUFFER_SIZE ? MAX_BUFFER_SIZE : size);
  if (size > 0) {
    size = (16*1024) * ((size + (16*1024 - 1)) / (16*1024));
    buffer_size = size;
  } else {
    buffer_size = DEFAULT_BUFFER_SIZE;
    printf("Parameter File Error:  invalid BUFFER_SIZE: \"%s\", defaults to : %d\n",
	   charPtr, buffer_size);
  }
  DBG_PRINT(("Buffer size is: %d\n", buffer_size));
}


/*===========================================================================*
 *
 * getBufferSize ()
 *
 *      returns the buffer size read from the parameter file.  Size is
 *  in bits- not in units of 16k as written to the sequence header.
 *
 * RETURNS:     int (or -1 if invalid)
 *
 * SIDE EFFECTS:   none
 *
 *===========================================================================*/
int getBufferSize ()
{
  return buffer_size;
}