h263.c

/*
 * H263/MPEG4 backend for ffmpeg encoder and decoder
 * Copyright (c) 2000,2001 Fabrice Bellard.
 * H263+ support.
 * Copyright (c) 2001 Juan J. Sierralta P.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * ac prediction encoding & b-frame support by Michael Niedermayer <michaelni@gmx.at>
 */
 
//#define DEBUG
#include "common.h"
#include "dsputil.h"
#include "avcodec.h"
#include "mpegvideo.h"
#include "h263data.h"
#include "mpeg4data.h"

//rounded divison & shift
#define RSHIFT(a,b) ((a) > 0 ? ((a) + (1<<((b)-1)))>>(b) : ((a) + (1<<((b)-1))-1)>>(b))

#define PRINT_MB_TYPE(a) ;
//#define PRINT_MB_TYPE(a) printf(a);

static void h263_encode_block(MpegEncContext * s, DCTELEM * block,
			      int n);
static void h263_encode_motion(MpegEncContext * s, int val, int fcode);
static void h263p_encode_umotion(MpegEncContext * s, int val);
static void mpeg4_encode_block(MpegEncContext * s, DCTELEM * block,
			       int n, int dc, UINT8 *scan_table, 
                               PutBitContext *dc_pb, PutBitContext *ac_pb);
static int h263_decode_motion(MpegEncContext * s, int pred, int fcode);
static int h263p_decode_umotion(MpegEncContext * s, int pred);
static int h263_decode_block(MpegEncContext * s, DCTELEM * block,
                             int n, int coded);
static inline int mpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr);
static inline int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
                              int n, int coded);
static int h263_pred_dc(MpegEncContext * s, int n, UINT16 **dc_val_ptr);
static inline int mpeg4_pred_dc(MpegEncContext * s, int n, UINT16 **dc_val_ptr, int *dir_ptr);
static void mpeg4_inv_pred_ac(MpegEncContext * s, INT16 *block, int n,
                              int dir);
static void mpeg4_decode_sprite_trajectory(MpegEncContext * s);

extern UINT32 inverse[256];

static UINT16 mv_penalty[MAX_FCODE+1][MAX_MV*2+1];
static UINT8 fcode_tab[MAX_MV*2+1];
static UINT8 umv_fcode_tab[MAX_MV*2+1];

static UINT16 uni_DCtab_lum  [512][2];
static UINT16 uni_DCtab_chrom[512][2];

int h263_get_picture_format(int width, int height)
{
    int format;

    if (width == 128 && height == 96)
        format = 1;
    else if (width == 176 && height == 144)
        format = 2;
    else if (width == 352 && height == 288)
        format = 3;
    else if (width == 704 && height == 576)
        format = 4;
    else if (width == 1408 && height == 1152)
        format = 5;
    else
        format = 7;
    return format;
}

void h263_encode_picture_header(MpegEncContext * s, int picture_number)
{
    int format;

    align_put_bits(&s->pb);

    /* Update the pointer to last GOB */
    s->ptr_lastgob = pbBufPtr(&s->pb);
    s->gob_number = 0;

    put_bits(&s->pb, 22, 0x20); /* PSC */
    put_bits(&s->pb, 8, (((INT64)s->picture_number * 30 * FRAME_RATE_BASE) / 
                         s->frame_rate) & 0xff);

    put_bits(&s->pb, 1, 1);	/* marker */
    put_bits(&s->pb, 1, 0);	/* h263 id */
    put_bits(&s->pb, 1, 0);	/* split screen off */
    put_bits(&s->pb, 1, 0);	/* camera  off */
    put_bits(&s->pb, 1, 0);	/* freeze picture release off */
    
    format = h263_get_picture_format(s->width, s->height);
    if (!s->h263_plus) {
        /* H.263v1 */
        put_bits(&s->pb, 3, format);
        put_bits(&s->pb, 1, (s->pict_type == P_TYPE));
        /* By now UMV IS DISABLED ON H.263v1, since the restrictions
        of H.263v1 UMV implies to check the predicted MV after
        calculation of the current MB to see if we're on the limits */
        put_bits(&s->pb, 1, 0);	/* unrestricted motion vector: off */
        put_bits(&s->pb, 1, 0);	/* SAC: off */
        put_bits(&s->pb, 1, 0);	/* advanced prediction mode: off */
        put_bits(&s->pb, 1, 0);	/* not PB frame */
        put_bits(&s->pb, 5, s->qscale);
        put_bits(&s->pb, 1, 0);	/* Continuous Presence Multipoint mode: off */
    } else {
        /* H.263v2 */
        /* H.263 Plus PTYPE */
        put_bits(&s->pb, 3, 7);
        put_bits(&s->pb,3,1); /* Update Full Extended PTYPE */
        if (format == 7)
            put_bits(&s->pb,3,6); /* Custom Source Format */
        else
            put_bits(&s->pb, 3, format);
            
        put_bits(&s->pb,1,0); /* Custom PCF: off */
        s->umvplus = (s->pict_type == P_TYPE) && s->unrestricted_mv;
        put_bits(&s->pb, 1, s->umvplus); /* Unrestricted Motion Vector */
        put_bits(&s->pb,1,0); /* SAC: off */
        put_bits(&s->pb,1,0); /* Advanced Prediction Mode: off */
        put_bits(&s->pb,1,s->h263_aic); /* Advanced Intra Coding */
        put_bits(&s->pb,1,0); /* Deblocking Filter: off */
        put_bits(&s->pb,1,0); /* Slice Structured: off */
        put_bits(&s->pb,1,0); /* Reference Picture Selection: off */
        put_bits(&s->pb,1,0); /* Independent Segment Decoding: off */
        put_bits(&s->pb,1,0); /* Alternative Inter VLC: off */
        put_bits(&s->pb,1,0); /* Modified Quantization: off */
        put_bits(&s->pb,1,1); /* "1" to prevent start code emulation */
        put_bits(&s->pb,3,0); /* Reserved */
		
        put_bits(&s->pb, 3, s->pict_type == P_TYPE);
		
        put_bits(&s->pb,1,0); /* Reference Picture Resampling: off */
        put_bits(&s->pb,1,0); /* Reduced-Resolution Update: off */
        if (s->pict_type == I_TYPE)
            s->no_rounding = 0;
        else
            s->no_rounding ^= 1;
        put_bits(&s->pb,1,s->no_rounding); /* Rounding Type */
        put_bits(&s->pb,2,0); /* Reserved */
        put_bits(&s->pb,1,1); /* "1" to prevent start code emulation */
		
        /* This should be here if PLUSPTYPE */
        put_bits(&s->pb, 1, 0);	/* Continuous Presence Multipoint mode: off */
		
		if (format == 7) {
            /* Custom Picture Format (CPFMT) */
		
	    if (s->aspect_ratio_info)
            put_bits(&s->pb,4,s->aspect_ratio_info);
	    else
            put_bits(&s->pb,4,2); /* Aspect ratio: CIF 12:11 (4:3) picture */
            put_bits(&s->pb,9,(s->width >> 2) - 1);
            put_bits(&s->pb,1,1); /* "1" to prevent start code emulation */
            put_bits(&s->pb,9,(s->height >> 2));
        }
        
        /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */
        if (s->umvplus)
            put_bits(&s->pb,1,1); /* Limited according tables of Annex D */
        put_bits(&s->pb, 5, s->qscale);
    }

    put_bits(&s->pb, 1, 0);	/* no PEI */
}

int h263_encode_gob_header(MpegEncContext * s, int mb_line)
{
    int pdif=0;
    
    /* Check to see if we need to put a new GBSC */
    /* for RTP packetization                    */
    if (s->rtp_mode) {
        pdif = pbBufPtr(&s->pb) - s->ptr_lastgob;
        if (pdif >= s->rtp_payload_size) {
            /* Bad luck, packet must be cut before */
            align_put_bits(&s->pb);
            flush_put_bits(&s->pb);
            /* Call the RTP callback to send the last GOB */
            if (s->rtp_callback) {
                pdif = pbBufPtr(&s->pb) - s->ptr_lastgob;
                s->rtp_callback(s->ptr_lastgob, pdif, s->gob_number);
            }
            s->ptr_lastgob = pbBufPtr(&s->pb);
            put_bits(&s->pb, 17, 1); /* GBSC */
            s->gob_number = mb_line / s->gob_index;
            put_bits(&s->pb, 5, s->gob_number); /* GN */
            put_bits(&s->pb, 2, s->pict_type == I_TYPE); /* GFID */
            put_bits(&s->pb, 5, s->qscale); /* GQUANT */
            //fprintf(stderr,"\nGOB: %2d size: %d", s->gob_number - 1, pdif);
            return pdif;
       } else if (pdif + s->mb_line_avgsize >= s->rtp_payload_size) {
           /* Cut the packet before we can't */
           align_put_bits(&s->pb);
           flush_put_bits(&s->pb);
           /* Call the RTP callback to send the last GOB */
           if (s->rtp_callback) {
               pdif = pbBufPtr(&s->pb) - s->ptr_lastgob;
               s->rtp_callback(s->ptr_lastgob, pdif, s->gob_number);
           }
           s->ptr_lastgob = pbBufPtr(&s->pb);
           put_bits(&s->pb, 17, 1); /* GBSC */
           s->gob_number = mb_line / s->gob_index;
           put_bits(&s->pb, 5, s->gob_number); /* GN */
           put_bits(&s->pb, 2, s->pict_type == I_TYPE); /* GFID */
           put_bits(&s->pb, 5, s->qscale); /* GQUANT */
           //fprintf(stderr,"\nGOB: %2d size: %d", s->gob_number - 1, pdif);
           return pdif;
       }
   }
   return 0;
}

static inline int decide_ac_pred(MpegEncContext * s, DCTELEM block[6][64], int dir[6])
{
    int score0=0, score1=0;
    int i, n;

    for(n=0; n<6; n++){
        INT16 *ac_val, *ac_val1;

        ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
        ac_val1= ac_val;
        if(dir[n]){
            ac_val-= s->block_wrap[n]*16;
            for(i=1; i<8; i++){
                const int level= block[n][block_permute_op(i   )];
                score0+= ABS(level);
                score1+= ABS(level - ac_val[i+8]);
                ac_val1[i  ]=    block[n][block_permute_op(i<<3)];
                ac_val1[i+8]= level;
            }
        }else{
            ac_val-= 16;
            for(i=1; i<8; i++){
                const int level= block[n][block_permute_op(i<<3)];
                score0+= ABS(level);
                score1+= ABS(level - ac_val[i]);
                ac_val1[i  ]= level;
                ac_val1[i+8]=    block[n][block_permute_op(i   )];
            }
        }
    }

    return score0 > score1 ? 1 : 0;    
}

void mpeg4_encode_mb(MpegEncContext * s,
		    DCTELEM block[6][64],
		    int motion_x, int motion_y)
{
    int cbpc, cbpy, i, pred_x, pred_y;
    int bits;
    PutBitContext * const pb2    = s->data_partitioning                         ? &s->pb2    : &s->pb;
    PutBitContext * const tex_pb = s->data_partitioning && s->pict_type!=B_TYPE ? &s->tex_pb : &s->pb;
    PutBitContext * const dc_pb  = s->data_partitioning && s->pict_type!=I_TYPE ? &s->pb2    : &s->pb;
    const int interleaved_stats= (s->flags&CODEC_FLAG_PASS1) && !s->data_partitioning ? 1 : 0;
    
    //    printf("**mb x=%d y=%d\n", s->mb_x, s->mb_y);
    if (!s->mb_intra) {
        /* compute cbp */
        int cbp = 0;
        for (i = 0; i < 6; i++) {
            if (s->block_last_index[i] >= 0)
                cbp |= 1 << (5 - i);
        }

        if(s->pict_type==B_TYPE){
            static const int mb_type_table[8]= {-1, 2, 3, 1,-1,-1,-1, 0}; /* convert from mv_dir to type */
            int mb_type=  mb_type_table[s->mv_dir];
            
            if(s->mb_x==0){
                s->last_mv[0][0][0]= 
                s->last_mv[0][0][1]= 
                s->last_mv[1][0][0]= 
                s->last_mv[1][0][1]= 0;
            }

            /* nothing to do if this MB was skiped in the next P Frame */
            if(s->mbskip_table[s->mb_y * s->mb_width + s->mb_x]){
                s->skip_count++;
                s->mv[0][0][0]= 
                s->mv[0][0][1]= 
                s->mv[1][0][0]= 
                s->mv[1][0][1]= 0;
                s->mv_dir= MV_DIR_FORWARD; //doesnt matter
                return;
            }

            if ((cbp | motion_x | motion_y | mb_type) ==0) {
                /* direct MB with MV={0,0} */
                put_bits(&s->pb, 1, 1); /* mb not coded modb1=1 */

                if(interleaved_stats){
                    s->misc_bits++;
                    s->last_bits++;
                }
                s->skip_count++;
                return;
            }
            put_bits(&s->pb, 1, 0);	/* mb coded modb1=0 */
            put_bits(&s->pb, 1, cbp ? 0 : 1); /* modb2 */ //FIXME merge
            put_bits(&s->pb, mb_type+1, 1); // this table is so simple that we dont need it :)
            if(cbp) put_bits(&s->pb, 6, cbp);
            
            if(cbp && mb_type)
                put_bits(&s->pb, 1, 0); /* no q-scale change */

            if(interleaved_stats){
                bits= get_bit_count(&s->pb);
                s->misc_bits+= bits - s->last_bits;
                s->last_bits=bits;
            }

            switch(mb_type)
            {
            case 0: /* direct */
                h263_encode_motion(s, motion_x, 1);
                h263_encode_motion(s, motion_y, 1);                
                break;
            case 1: /* bidir */
                h263_encode_motion(s, s->mv[0][0][0] - s->last_mv[0][0][0], s->f_code);
                h263_encode_motion(s, s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
                h263_encode_motion(s, s->mv[1][0][0] - s->last_mv[1][0][0], s->b_code);
                h263_encode_motion(s, s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
                s->last_mv[0][0][0]= s->mv[0][0][0];
                s->last_mv[0][0][1]= s->mv[0][0][1];
                s->last_mv[1][0][0]= s->mv[1][0][0];
                s->last_mv[1][0][1]= s->mv[1][0][1];
                break;
            case 2: /* backward */
                h263_encode_motion(s, motion_x - s->last_mv[1][0][0], s->b_code);
                h263_encode_motion(s, motion_y - s->last_mv[1][0][1], s->b_code);
                s->last_mv[1][0][0]= motion_x;
                s->last_mv[1][0][1]= motion_y;
                break;
            case 3: /* forward */
                h263_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);
                h263_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);
                s->last_mv[0][0][0]= motion_x;
                s->last_mv[0][0][1]= motion_y;
                break;
            default:
                printf("unknown mb type\n");
                return;
            }

            if(interleaved_stats){
                bits= get_bit_count(&s->pb);
                s->mv_bits+= bits - s->last_bits;
                s->last_bits=bits;
            }

            /* encode each block */
            for (i = 0; i < 6; i++) {
                mpeg4_encode_block(s, block[i], i, 0, zigzag_direct, NULL, &s->pb);
            }

            if(interleaved_stats){
                bits= get_bit_count(&s->pb);
                s->p_tex_bits+= bits - s->last_bits;
                s->last_bits=bits;
            }
        }else{ /* s->pict_type==B_TYPE */
            if ((cbp | motion_x | motion_y) == 0 && s->mv_type==MV_TYPE_16X16) {
                /* check if the B frames can skip it too, as we must skip it if we skip here 
                   why didnt they just compress the skip-mb bits instead of reusing them ?! */
                if(s->max_b_frames>0){
                    int i;
                    int x,y, offset;
                    uint8_t *p_pic;

                    x= s->mb_x*16;
                    y= s->mb_y*16;
                    if(x+16 > s->width)  x= s->width-16;
                    if(y+16 > s->height) y= s->height-16;

                    offset= x + y*s->linesize;
                    p_pic= s->new_picture[0] + offset;
                    
                    s->mb_skiped=1;
                    for(i=0; i<s->max_b_frames; i++){
                        uint8_t *b_pic;
                        int diff;

                        if(s->coded_order[i+1].pict_type!=B_TYPE) break;

                        b_pic= s->coded_order[i+1].picture[0] + offset;
                        diff= pix_abs16x16(p_pic, b_pic, s->linesize);
                        if(diff>s->qscale*70){ //FIXME check that 70 is optimal
                            s->mb_skiped=0;
                            break;
                        }
                    }
                }else
                    s->mb_skiped=1; 

                if(s->mb_skiped==1){
                    /* skip macroblock */
                    put_bits(&s->pb, 1, 1);

                    if(interleaved_stats){
                        s->misc_bits++;
                        s->last_bits++;
                    }
                    s->skip_count++;
                    return;
                }
            }

            put_bits(&s->pb, 1, 0);	/* mb coded */
            if(s->mv_type==MV_TYPE_16X16){
                cbpc = cbp & 3;
                put_bits(&s->pb,
                        inter_MCBPC_bits[cbpc],
                        inter_MCBPC_code[cbpc]);
                cbpy = cbp >> 2;
                cbpy ^= 0xf;
                put_bits(pb2, cbpy_tab[cbpy][1], cbpy_tab[cbpy][0]);
                    
                if(interleaved_stats){
                    bits= get_bit_count(&s->pb);
                    s->misc_bits+= bits - s->last_bits;
                    s->last_bits=bits;
                }

                /* motion vectors: 16x16 mode */
                h263_pred_motion(s, 0, &pred_x, &pred_y);
            
                h263_encode_motion(s, motion_x - pred_x, s->f_code);
                h263_encode_motion(s, motion_y - pred_y, s->f_code);
            }else{
                cbpc = (cbp & 3)+16;
                put_bits(&s->pb,
                        inter_MCBPC_bits[cbpc],
                        inter_MCBPC_code[cbpc]);
                cbpy = cbp >> 2;
                cbpy ^= 0xf;
                put_bits(pb2, cbpy_tab[cbpy][1], cbpy_tab[cbpy][0]);

                if(interleaved_stats){
                    bits= get_bit_count(&s->pb);
                    s->misc_bits+= bits - s->last_bits;
                    s->last_bits=bits;
                }

                for(i=0; i<4; i++){
                    /* motion vectors: 8x8 mode*/
                    h263_pred_motion(s, i, &pred_x, &pred_y);

                    h263_encode_motion(s, s->motion_val[ s->block_index[i] ][0] - pred_x, s->f_code);
                    h263_encode_motion(s, s->motion_val[ s->block_index[i] ][1] - pred_y, s->f_code);
                }
            }

            if(interleaved_stats){ 
                bits= get_bit_count(&s->pb);
                s->mv_bits+= bits - s->last_bits;
                s->last_bits=bits;
            }

            /* encode each block */
            for (i = 0; i < 6; i++) {
                mpeg4_encode_block(s, block[i], i, 0, zigzag_direct, NULL, tex_pb);
            }

            if(interleaved_stats){
                bits= get_bit_count(&s->pb);
                s->p_tex_bits+= bits - s->last_bits;
                s->last_bits=bits;
            }
            s->p_count++;
        }
    } else {
        int cbp;
        int dc_diff[6];   //dc values with the dc prediction subtracted 
        int dir[6];  //prediction direction
        int zigzag_last_index[6];
        UINT8 *scan_table[6];

        for(i=0; i<6; i++){
            const int level= block[i][0];
            UINT16 *dc_ptr;

            dc_diff[i]= level - mpeg4_pred_dc(s, i, &dc_ptr, &dir[i]);
            if (i < 4) {
                *dc_ptr = level * s->y_dc_scale;
            } else {
                *dc_ptr = level * s->c_dc_scale;
            }
        }

        s->ac_pred= decide_ac_pred(s, block, dir);

        if(s->ac_pred){
            for(i=0; i<6; i++){
                UINT8 *st;
                int last_index;

                mpeg4_inv_pred_ac(s, block[i], i, dir[i]);
                if (dir[i]==0) st = ff_alternate_vertical_scan; /* left */
                else           st = ff_alternate_horizontal_scan; /* top */

                for(last_index=63; last_index>=0; last_index--) //FIXME optimize
                    if(block[i][st[last_index]]) break;
                zigzag_last_index[i]= s->block_last_index[i];
                s->block_last_index[i]= last_index;
                scan_table[i]= st;
            }
        }else{
            for(i=0; i<6; i++)
                scan_table[i]= zigzag_direct;
        }

        /* compute cbp */
        cbp = 0;
        for (i = 0; i < 6; i++) {
            if (s->block_last_index[i] >= 1)
                cbp |= 1 << (5 - i);
        }

        cbpc = cbp & 3;
        if (s->pict_type == I_TYPE) {
            put_bits(&s->pb,
                intra_MCBPC_bits[cbpc],
                intra_MCBPC_code[cbpc]);
        } else {
            put_bits(&s->pb, 1, 0);	/* mb coded */
            put_bits(&s->pb,
                inter_MCBPC_bits[cbpc + 4],
                inter_MCBPC_code[cbpc + 4]);
        }
        put_bits(pb2, 1, s->ac_pred);
        cbpy = cbp >> 2;
        put_bits(pb2, cbpy_tab[cbpy][1], cbpy_tab[cbpy][0]);

        if(interleaved_stats){
            bits= get_bit_count(&s->pb);
            s->misc_bits+= bits - s->last_bits;
            s->last_bits=bits;
        }

        /* encode each block */
        for (i = 0; i < 6; i++) {
            mpeg4_encode_block(s, block[i], i, dc_diff[i], scan_table[i], dc_pb, tex_pb);
        }

        if(interleaved_stats){
            bits= get_bit_count(&s->pb);
            s->i_tex_bits+= bits - s->last_bits;
            s->last_bits=bits;
        }
        s->i_count++;

        /* restore ac coeffs & last_index stuff if we messed them up with the prediction */
        if(s->ac_pred){
            for(i=0; i<6; i++){
                int j;    
                INT16 *ac_val;

                ac_val = s->ac_val[0][0] + s->block_index[i] * 16;

                if(dir[i]){
                    for(j=1; j<8; j++) 
                        block[i][block_permute_op(j   )]= ac_val[j+8];
                }else{
                    for(j=1; j<8; j++) 
                        block[i][block_permute_op(j<<3)]= ac_val[j  ];
                }
                s->block_last_index[i]= zigzag_last_index[i];
            }
        }
    }
}

void h263_encode_mb(MpegEncContext * s,
		    DCTELEM block[6][64],
		    int motion_x, int motion_y)
{
    int cbpc, cbpy, i, cbp, pred_x, pred_y;
    INT16 pred_dc;
    INT16 rec_intradc[6];
    UINT16 *dc_ptr[6];
           
    //printf("**mb x=%d y=%d\n", s->mb_x, s->mb_y);
    if (!s->mb_intra) {
        /* compute cbp */
        cbp = 0;
        for (i = 0; i < 6; i++) {
            if (s->block_last_index[i] >= 0)
                cbp |= 1 << (5 - i);
        }
        if ((cbp | motion_x | motion_y) == 0) {
            /* skip macroblock */
            put_bits(&s->pb, 1, 1);
            return;
        }
        put_bits(&s->pb, 1, 0);	/* mb coded */
        cbpc = cbp & 3;
        put_bits(&s->pb,
		    inter_MCBPC_bits[cbpc],
		    inter_MCBPC_code[cbpc]);
        cbpy = cbp >> 2;
        cbpy ^= 0xf;
        put_bits(&s->pb, cbpy_tab[cbpy][1], cbpy_tab[cbpy][0]);

        /* motion vectors: 16x16 mode only now */
        h263_pred_motion(s, 0, &pred_x, &pred_y);
      
        if (!s->umvplus) {  
            h263_encode_motion(s, motion_x - pred_x, s->f_code);
            h263_encode_motion(s, motion_y - pred_y, s->f_code);
        }
        else {
            h263p_encode_umotion(s, motion_x - pred_x);
            h263p_encode_umotion(s, motion_y - pred_y);
            if (((motion_x - pred_x) == 1) && ((motion_y - pred_y) == 1))
                /* To prevent Start Code emulation */
                put_bits(&s->pb,1,1);
        }
    } else {
        int li = s->h263_aic ? 0 : 1;
        
        cbp = 0;
        for(i=0; i<6; i++) {
            /* Predict DC */
            if (s->h263_aic && s->mb_intra) {
                INT16 level = block[i][0];
            
                pred_dc = h263_pred_dc(s, i, &dc_ptr[i]);
                level -= pred_dc;
                /* Quant */
                if (level < 0)
                    level = (level + (s->qscale >> 1))/(s->y_dc_scale);
                else
                    level = (level - (s->qscale >> 1))/(s->y_dc_scale);
                    
                /* AIC can change CBP */
                if (level == 0 && s->block_last_index[i] == 0)
                    s->block_last_index[i] = -1;
                else if (level < -127)
                    level = -127;
                else if (level > 127)
                    level = 127;
                
                block[i][0] = level;
                /* Reconstruction */ 
                rec_intradc[i] = (s->y_dc_scale*level) + pred_dc;
                /* Oddify */
                rec_intradc[i] |= 1;
                //if ((rec_intradc[i] % 2) == 0)
                //    rec_intradc[i]++;
                /* Clipping */
                if (rec_intradc[i] < 0)
                    rec_intradc[i] = 0;
                else if (rec_intradc[i] > 2047)
                    rec_intradc[i] = 2047;
                                
                /* Update AC/DC tables */
                *dc_ptr[i] = rec_intradc[i];
            }
            /* compute cbp */
            if (s->block_last_index[i] >= li)
                cbp |= 1 << (5 - i);
        }

        cbpc = cbp & 3;
        if (s->pict_type == I_TYPE) {
            put_bits(&s->pb,
                intra_MCBPC_bits[cbpc],
                intra_MCBPC_code[cbpc]);
        } else {
            put_bits(&s->pb, 1, 0);	/* mb coded */
            put_bits(&s->pb,
                inter_MCBPC_bits[cbpc + 4],
                inter_MCBPC_code[cbpc + 4]);
        }
        if (s->h263_aic) {
            /* XXX: currently, we do not try to use ac prediction */
            put_bits(&s->pb, 1, 0);	/* no AC prediction */
        }
        cbpy = cbp >> 2;
        put_bits(&s->pb, cbpy_tab[cbpy][1], cbpy_tab[cbpy][0]);
    }

    for(i=0; i<6; i++) {
        /* encode each block */
        h263_encode_block(s, block[i], i);
    
        /* Update INTRADC for decoding */
        if (s->h263_aic && s->mb_intra) {
            block[i][0] = rec_intradc[i];
            
        }
    }
}

static int h263_pred_dc(MpegEncContext * s, int n, UINT16 **dc_val_ptr)
{
    int x, y, wrap, a, c, pred_dc, scale;
    INT16 *dc_val, *ac_val;

    /* find prediction */
    if (n < 4) {
        x = 2 * s->mb_x + 1 + (n & 1);
        y = 2 * s->mb_y + 1 + ((n & 2) >> 1);
        wrap = s->mb_width * 2 + 2;
        dc_val = s->dc_val[0];
        ac_val = s->ac_val[0][0];
        scale = s->y_dc_scale;
    } else {
        x = s->mb_x + 1;
        y = s->mb_y + 1;
        wrap = s->mb_width + 2;
        dc_val = s->dc_val[n - 4 + 1];
        ac_val = s->ac_val[n - 4 + 1][0];
        scale = s->c_dc_scale;
    }
    /* B C
     * A X 
     */
    a = dc_val[(x - 1) + (y) * wrap];
    c = dc_val[(x) + (y - 1) * wrap];
    
    /* No prediction outside GOB boundary */
    if (s->first_slice_line && ((n < 2) || (n > 3)))
        c = 1024;
    pred_dc = 1024;
    /* just DC prediction */
    if (a != 1024 && c != 1024)
        pred_dc = (a + c) >> 1;
    else if (a != 1024)
        pred_dc = a;
    else
        pred_dc = c;
    
    /* we assume pred is positive */
    //pred_dc = (pred_dc + (scale >> 1)) / scale;
    *dc_val_ptr = &dc_val[x + y * wrap];
    return pred_dc;
}


void h263_pred_acdc(MpegEncContext * s, INT16 *block, int n)
{
    int x, y, wrap, a, c, pred_dc, scale, i;
    INT16 *dc_val, *ac_val, *ac_val1;

    /* find prediction */
    if (n < 4) {
        x = 2 * s->mb_x + 1 + (n & 1);
        y = 2 * s->mb_y + 1 + ((n & 2) >> 1);
        wrap = s->mb_width * 2 + 2;
        dc_val = s->dc_val[0];
        ac_val = s->ac_val[0][0];
        scale = s->y_dc_scale;
    } else {
        x = s->mb_x + 1;
        y = s->mb_y + 1;
        wrap = s->mb_width + 2;
        dc_val = s->dc_val[n - 4 + 1];
        ac_val = s->ac_val[n - 4 + 1][0];
        scale = s->c_dc_scale;
    }
    
    ac_val += ((y) * wrap + (x)) * 16;
    ac_val1 = ac_val;
    
    /* B C
     * A X 
     */
    a = dc_val[(x - 1) + (y) * wrap];
    c = dc_val[(x) + (y - 1) * wrap];
    
    /* No prediction outside GOB boundary */
    if (s->first_slice_line && ((n < 2) || (n > 3)))
        c = 1024;
    pred_dc = 1024;
    if (s->ac_pred) {
        if (s->h263_aic_dir) {
            /* left prediction */
            if (a != 1024) {
                ac_val -= 16;
                for(i=1;i<8;i++) {
                    block[block_permute_op(i*8)] += ac_val[i];
                }
                pred_dc = a;
            }
        } else {
            /* top prediction */
            if (c != 1024) {
                ac_val -= 16 * wrap;
                for(i=1;i<8;i++) {
                    block[block_permute_op(i)] += ac_val[i + 8];
                }
                pred_dc = c;
            }
        }
    } else {
        /* just DC prediction */
        if (a != 1024 && c != 1024)
            pred_dc = (a + c) >> 1;
        else if (a != 1024)
            pred_dc = a;
        else
            pred_dc = c;
    }
    
    /* we assume pred is positive */
    block[0]=block[0]*scale + pred_dc;
    
    if (block[0] < 0)
        block[0] = 0;
    else if (!(block[0] & 1))
        block[0]++;
    
    /* Update AC/DC tables */
    dc_val[(x) + (y) * wrap] = block[0];
    
    /* left copy */
    for(i=1;i<8;i++)
        ac_val1[i] = block[block_permute_op(i * 8)];
    /* top copy */
    for(i=1;i<8;i++)
        ac_val1[8 + i] = block[block_permute_op(i)];
}

INT16 *h263_pred_motion(MpegEncContext * s, int block, 
                        int *px, int *py)
{
    int xy, wrap;
    INT16 *A, *B, *C, *mot_val;
    static const int off[4]= {2, 1, 1, -1};

    wrap = s->block_wrap[0];
    xy = s->block_index[block];

    mot_val = s->motion_val[xy];

    A = s->motion_val[xy - 1];
    /* special case for first (slice) line */
    if ((s->mb_y == 0 || s->first_slice_line) && block<3) {
        // we cant just change some MVs to simulate that as we need them for the B frames (and ME)
        // and if we ever support non rectangular objects than we need to do a few ifs here anyway :(
        if(block==0){ //most common case
            if(s->mb_x  == s->resync_mb_x){ //rare
                *px= *py = 0;
            }else if(s->mb_x + 1 == s->resync_mb_x){ //rare
                C = s->motion_val[xy + off[block] - wrap];
                if(s->mb_x==0){
                    *px = C[0];
                    *py = C[1];
                }else{
                    *px = mid_pred(A[0], 0, C[0]);
                    *py = mid_pred(A[1], 0, C[1]);
                }
            }else{
                *px = A[0];
                *py = A[1];
            }
        }else if(block==1){
            if(s->mb_x + 1 == s->resync_mb_x){ //rare
                C = s->motion_val[xy + off[block] - wrap];
                *px = mid_pred(A[0], 0, C[0]);
                *py = mid_pred(A[1], 0, C[1]);
            }else{
                *px = A[0];
                *py = A[1];
            }
        }else{ /* block==2*/
            B = s->motion_val[xy - wrap];
            C = s->motion_val[xy + off[block] - wrap];
            if(s->mb_x == s->resync_mb_x) //rare
                A[0]=A[1]=0;
    
            *px = mid_pred(A[0], B[0], C[0]);
            *py = mid_pred(A[1], B[1], C[1]);
        }
    } else {
        B = s->motion_val[xy - wrap];
        C = s->motion_val[xy + off[block] - wrap];
        *px = mid_pred(A[0], B[0], C[0]);
        *py = mid_pred(A[1], B[1], C[1]);
    }
    return mot_val;
}

static void h263_encode_motion(MpegEncContext * s, int val, int f_code)
{
    int range, l, m, bit_size, sign, code, bits;

    if (val == 0) {
        /* zero vector */
        code = 0;
        put_bits(&s->pb, mvtab[code][1], mvtab[code][0]);
    } else {
        bit_size = f_code - 1;
        range = 1 << bit_size;
        /* modulo encoding */
        l = range * 32;
        m = 2 * l;
        if (val < -l) {
            val += m;
        } else if (val >= l) {
            val -= m;
        }

        if (val >= 0) {
            sign = 0;
        } else {
            val = -val;
            sign = 1;
        }
        val--;
        code = (val >> bit_size) + 1;
        bits = val & (range - 1);

        put_bits(&s->pb, mvtab[code][1] + 1, (mvtab[code][0] << 1) | sign); 
        if (bit_size > 0) {
            put_bits(&s->pb, bit_size, bits);
        }
    }
}

/* Encode MV differences on H.263+ with Unrestricted MV mode */
static void h263p_encode_umotion(MpegEncContext * s, int val)
{
    short sval = 0; 
    short i = 0;
    short n_bits = 0;
    short temp_val;
    int code = 0;
    int tcode;
    
    if ( val == 0)
        put_bits(&s->pb, 1, 1);
    else if (val == 1)
        put_bits(&s->pb, 3, 0);
    else if (val == -1)
        put_bits(&s->pb, 3, 2);
    else {
        
        sval = ((val < 0) ? (short)(-val):(short)val);
        temp_val = sval;
        
        while (temp_val != 0) {
            temp_val = temp_val >> 1;
            n_bits++;
        }
        
        i = n_bits - 1;
        while (i > 0) {
            tcode = (sval & (1 << (i-1))) >> (i-1);
            tcode = (tcode << 1) | 1;
            code = (code << 2) | tcode;
            i--;
        }
        code = ((code << 1) | (val < 0)) << 1;
        put_bits(&s->pb, (2*n_bits)+1, code);
        //printf("\nVal = %d\tCode = %d", sval, code);
    }
}

static void init_mv_penalty_and_fcode(MpegEncContext *s)
{
    int f_code;
    int mv;
    for(f_code=1; f_code<=MAX_FCODE; f_code++){
        for(mv=-MAX_MV; mv<=MAX_MV; mv++){
            int len;

            if(mv==0) len= mvtab[0][1];
            else{
                int val, bit_size, range, code;

                bit_size = s->f_code - 1;
                range = 1 << bit_size;

                val=mv;
                if (val < 0) 
                    val = -val;
                val--;
                code = (val >> bit_size) + 1;
                if(code<33){
                    len= mvtab[code][1] + 1 + bit_size;
                }else{
                    len= mvtab[32][1] + 2 + bit_size;
                }
            }

            mv_penalty[f_code][mv+MAX_MV]= len;
        }
    }

    for(f_code=MAX_FCODE; f_code>0; f_code--){
        for(mv=-(16<<f_code); mv<(16<<f_code); mv++){
            fcode_tab[mv+MAX_MV]= f_code;
        }
    }

    for(mv=0; mv<MAX_MV*2+1; mv++){
        umv_fcode_tab[mv]= 1;
    }
}

static void init_uni_dc_tab(void)
{
    int level, uni_code, uni_len;

    for(level=-256; level<256; level++){
        int size, v, l;
        /* find number of bits */
        size = 0;
        v = abs(level);
        while (v) {
            v >>= 1;
	    size++;
        }

        if (level < 0)
            l= (-level) ^ ((1 << size) - 1);
        else
            l= level;

        /* luminance */
        uni_code= DCtab_lum[size][0];
        uni_len = DCtab_lum[size][1];

        if (size > 0) {
            uni_code<<=size; uni_code|=l;
            uni_len+=size;
            if (size > 8){
                uni_code<<=1; uni_code|=1;
                uni_len++;
            }
        }
        uni_DCtab_lum[level+256][0]= uni_code;
        uni_DCtab_lum[level+256][1]= uni_len;

        /* chrominance */
        uni_code= DCtab_chrom[size][0];
        uni_len = DCtab_chrom[size][1];
        
        if (size > 0) {
            uni_code<<=size; uni_code|=l;
            uni_len+=size;
            if (size > 8){
                uni_code<<=1; uni_code|=1;
                uni_len++;
            }
        }
        uni_DCtab_chrom[level+256][0]= uni_code;
        uni_DCtab_chrom[level+256][1]= uni_len;

    }
}

void h263_encode_init(MpegEncContext *s)
{
    static int done = 0;

    if (!done) {
        done = 1;

        init_uni_dc_tab();

        init_rl(&rl_inter);
        init_rl(&rl_intra);
        init_rl(&rl_intra_aic);

        init_mv_penalty_and_fcode(s);
    }
    s->mv_penalty= mv_penalty; //FIXME exact table for msmpeg4 & h263p
    
    // use fcodes >1 only for mpeg4 & h263 & h263p FIXME
    switch(s->codec_id){
    case CODEC_ID_MPEG4:
        s->fcode_tab= fcode_tab;
        s->min_qcoeff= -2048;
        s->max_qcoeff=  2047;
        break;
    case CODEC_ID_H263P:
        s->fcode_tab= umv_fcode_tab;
        s->min_qcoeff= -128;
        s->max_qcoeff=  127;
        break;
    default: //nothing needed default table allready set in mpegvideo.c
        s->min_qcoeff= -128;
        s->max_qcoeff=  127;
    }

    /* h263 type bias */
    //FIXME mpeg4 mpeg quantizer    
    s->intra_quant_bias=0;
    s->inter_quant_bias=-(1<<(QUANT_BIAS_SHIFT-2)); //(a - x/4)/x
}

static void h263_encode_block(MpegEncContext * s, DCTELEM * block, int n)
{
    int level, run, last, i, j, last_index, last_non_zero, sign, slevel, code;
    RLTable *rl;

    rl = &rl_inter;
    if (s->mb_intra && !s->h263_aic) {
        /* DC coef */
	    level = block[0];
        /* 255 cannot be represented, so we clamp */
        if (level > 254) {
            level = 254;
            block[0] = 254;
        }
        /* 0 cannot be represented also */
        else if (!level) {
            level = 1;
            block[0] = 1;
        }
	    if (level == 128)
	        put_bits(&s->pb, 8, 0xff);
	    else
	        put_bits(&s->pb, 8, level & 0xff);
	    i = 1;
    } else {
	    i = 0;
	    if (s->h263_aic && s->mb_intra)
	        rl = &rl_intra_aic;
    }
   
    /* AC coefs */
    last_index = s->block_last_index[n];
    last_non_zero = i - 1;
    for (; i <= last_index; i++) {
        j = zigzag_direct[i];
        level = block[j];
        if (level) {
            run = i - last_non_zero - 1;
            last = (i == last_index);
            sign = 0;
            slevel = level;
            if (level < 0) {
                sign = 1;
                level = -level;
            }
            code = get_rl_index(rl, last, run, level);
            put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
            if (code == rl->n) {
                put_bits(&s->pb, 1, last);
                put_bits(&s->pb, 6, run);
                put_bits(&s->pb, 8, slevel & 0xff);
            } else {
                put_bits(&s->pb, 1, sign);
            }
	        last_non_zero = i;
	    }
    }
}

/***************************************************/

void ff_mpeg4_stuffing(PutBitContext * pbc)
{
    int length;
    put_bits(pbc, 1, 0);
    length= (-get_bit_count(pbc))&7;
    if(length) put_bits(pbc, length, (1<<length)-1);
}

/* must be called before writing the header */
void ff_set_mpeg4_time(MpegEncContext * s, int picture_number){
    int time_div, time_mod;

    if(s->pict_type==I_TYPE){ //we will encode a vol header
        s->time_increment_resolution= s->frame_rate/ff_gcd(s->frame_rate, FRAME_RATE_BASE);
        if(s->time_increment_resolution>=256*256) s->time_increment_resolution= 256*128;

        s->time_increment_bits = av_log2(s->time_increment_resolution - 1) + 1;
    }

    s->time= picture_number*(INT64)FRAME_RATE_BASE*s->time_increment_resolution/s->frame_rate;
    time_div= s->time/s->time_increment_resolution;
    time_mod= s->time%s->time_increment_resolution;

    if(s->pict_type==B_TYPE){
        s->bp_time= s->last_non_b_time - s->time;
    }else{
        s->last_time_base= s->time_base;
        s->time_base= time_div;
        s->pp_time= s->time - s->last_non_b_time;
        s->last_non_b_time= s->time;
    }
}

static void mpeg4_encode_vol_header(MpegEncContext * s)
{
    int vo_ver_id=1; //must be 2 if we want GMC or q-pel
    char buf[255];

    s->vo_type= s->has_b_frames ? CORE_VO_TYPE : SIMPLE_VO_TYPE;

    put_bits(&s->pb, 16, 0);
    put_bits(&s->pb, 16, 0x100);        /* video obj */
    put_bits(&s->pb, 16, 0);
    put_bits(&s->pb, 16, 0x120);        /* video obj layer */

    put_bits(&s->pb, 1, 0);		/* random access vol */
    put_bits(&s->pb, 8, s->vo_type);	/* video obj type indication */
    put_bits(&s->pb, 1, 1);		/* is obj layer id= yes */
      put_bits(&s->pb, 4, vo_ver_id);	/* is obj layer ver id */
      put_bits(&s->pb, 3, 1);		/* is obj layer priority */
    if(s->aspect_ratio_info) 
        put_bits(&s->pb, 4, s->aspect_ratio_info);/* aspect ratio info */
    else
        put_bits(&s->pb, 4, 1);		/* aspect ratio info= sqare pixel */

    if(s->low_delay){
        put_bits(&s->pb, 1, 1);		/* vol control parameters= yes */
        put_bits(&s->pb, 2, 1);		/* chroma format YUV 420/YV12 */
        put_bits(&s->pb, 1, s->low_delay);
        put_bits(&s->pb, 1, 0);		/* vbv parameters= no */
    }else{
        put_bits(&s->pb, 1, 0);		/* vol control parameters= no */
    }

    put_bits(&s->pb, 2, RECT_SHAPE);	/* vol shape= rectangle */
    put_bits(&s->pb, 1, 1);		/* marker bit */
    
    put_bits(&s->pb, 16, s->time_increment_resolution);
    if (s->time_increment_bits < 1)
        s->time_increment_bits = 1;
    put_bits(&s->pb, 1, 1);		/* marker bit */
    put_bits(&s->pb, 1, 0);		/* fixed vop rate=no */
    put_bits(&s->pb, 1, 1);		/* marker bit */
    put_bits(&s->pb, 13, s->width);	/* vol width */
    put_bits(&s->pb, 1, 1);		/* marker bit */
    put_bits(&s->pb, 13, s->height);	/* vol height */
    put_bits(&s->pb, 1, 1);		/* marker bit */
    put_bits(&s->pb, 1, 0);		/* interlace */
    put_bits(&s->pb, 1, 1);		/* obmc disable */
    if (vo_ver_id == 1) {
        put_bits(&s->pb, 1, s->vol_sprite_usage=0);		/* sprite enable */
    }else{ /* vo_ver_id == 2 */
        put_bits(&s->pb, 2, s->vol_sprite_usage=0);		/* sprite enable */
    }
    put_bits(&s->pb, 1, 0);		/* not 8 bit */
    put_bits(&s->pb, 1, 0);		/* quant type= h263 style*/
    if (vo_ver_id != 1)
        put_bits(&s->pb, 1, s->quarter_sample=0);
    put_bits(&s->pb, 1, 1);		/* complexity estimation disable */
    s->resync_marker= s->rtp_mode;
    put_bits(&s->pb, 1, s->resync_marker ? 0 : 1);/* resync marker disable */
    put_bits(&s->pb, 1, s->data_partitioning ? 1 : 0);
    if(s->data_partitioning){
        put_bits(&s->pb, 1, 0);		/* no rvlc */
    }

    if (vo_ver_id != 1){
        put_bits(&s->pb, 1, 0);		/* newpred */
        put_bits(&s->pb, 1, 0);		/* reduced res vop */
    }
    put_bits(&s->pb, 1, 0);		/* scalability */

    ff_mpeg4_stuffing(&s->pb);
    put_bits(&s->pb, 16, 0);
    put_bits(&s->pb, 16, 0x1B2);	/* user_data */
    sprintf(buf, "FFmpeg%sb%s", FFMPEG_VERSION, LIBAVCODEC_BUILD_STR);
    put_string(&s->pb, buf);

    ff_mpeg4_stuffing(&s->pb);
}

/* write mpeg4 VOP header */
void mpeg4_encode_picture_header(MpegEncContext * s, int picture_number)
{
    int time_incr;
    int time_div, time_mod;
    
    if(s->pict_type==I_TYPE){
        s->no_rounding=0;
        if(picture_number==0 || !s->strict_std_compliance)
            mpeg4_encode_vol_header(s);
    }
    
//printf("num:%d rate:%d base:%d\n", s->picture_number, s->frame_rate, FRAME_RATE_BASE);