h263.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.7平台上编译为嵌入式图形界面操作系统。

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

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;

    }
}

#ifdef CONFIG_ENCODERS
static void init_uni_mpeg4_rl_tab(RLTable *rl, UINT32 *bits_tab, UINT8 *len_tab){
    int slevel, run, last;
    
    assert(MAX_LEVEL >= 64);
    assert(MAX_RUN   >= 63);

    for(slevel=-64; slevel<64; slevel++){
        if(slevel==0) continue;
        for(run=0; run<64; run++){
            for(last=0; last<=1; last++){
                const int index= UNI_MPEG4_ENC_INDEX(last, run, slevel+64);
                int level= slevel < 0 ? -slevel : slevel;
                int sign= slevel < 0 ? 1 : 0;
                int bits, len, code;
                int level1, run1;
                
                len_tab[index]= 100;
                     
                /* ESC0 */
                code= get_rl_index(rl, last, run, level);
                bits= rl->table_vlc[code][0];
                len=  rl->table_vlc[code][1];
                bits=bits*2+sign; len++;
                
                if(code!=rl->n && len < len_tab[index]){
                    bits_tab[index]= bits;
                    len_tab [index]= len;
                }
#if 1
                /* ESC1 */
                bits= rl->table_vlc[rl->n][0];
                len=  rl->table_vlc[rl->n][1];
                bits=bits*2;    len++; //esc1
                level1= level - rl->max_level[last][run];
                if(level1>0){
                    code= get_rl_index(rl, last, run, level1);
                    bits<<= rl->table_vlc[code][1];
                    len  += rl->table_vlc[code][1];
                    bits += rl->table_vlc[code][0];
                    bits=bits*2+sign; len++;
                
                    if(code!=rl->n && len < len_tab[index]){
                        bits_tab[index]= bits;
                        len_tab [index]= len;
                    }
                }
#endif 
#if 1
                /* ESC2 */
                bits= rl->table_vlc[rl->n][0];
                len=  rl->table_vlc[rl->n][1];
                bits=bits*4+2;    len+=2; //esc2
                run1 = run - rl->max_run[last][level] - 1;
                if(run1>=0){
                    code= get_rl_index(rl, last, run1, level);
                    bits<<= rl->table_vlc[code][1];
                    len  += rl->table_vlc[code][1];
                    bits += rl->table_vlc[code][0];
                    bits=bits*2+sign; len++;
                
                    if(code!=rl->n && len < len_tab[index]){
                        bits_tab[index]= bits;
                        len_tab [index]= len;
                    }
                }
#endif           
                /* ESC3 */        
                bits= rl->table_vlc[rl->n][0];
                len = rl->table_vlc[rl->n][1];
                bits=bits*4+3;    len+=2; //esc3
                bits=bits*2+last; len++;
                bits=bits*64+run; len+=6;
                bits=bits*2+1;    len++;  //marker
                bits=bits*4096+(slevel&0xfff); len+=12;
                bits=bits*2+1;    len++;  //marker
                
                if(len < len_tab[index]){
                    bits_tab[index]= bits;
                    len_tab [index]= 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_uni_mpeg4_rl_tab(&rl_intra, uni_mpeg4_intra_rl_bits, uni_mpeg4_intra_rl_len);
        init_uni_mpeg4_rl_tab(&rl_inter, uni_mpeg4_inter_rl_bits, uni_mpeg4_inter_rl_len);

        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;
        //Note for mpeg4 & h263 the dc-scale table will be set per frame as needed later 
    default: //nothing needed default table allready set in mpegvideo.c
        s->min_qcoeff= -128;
        s->max_qcoeff=  127;
        s->y_dc_scale_table=
        s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
    }

    if(s->mpeg_quant){
        s->intra_quant_bias= 3<<(QUANT_BIAS_SHIFT-3); //(a + x*3/8)/x
        s->inter_quant_bias= 0;
    }else{
        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 = s->intra_scantable.permutated[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;
	    }
    }
}
#endif

/***************************************************/
/**
 * add mpeg4 stuffing bits (01...1)
 */
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;
    }
    
    if(s->avctx->pts)
        s->time= (s->avctx->pts*s->time_increment_resolution + 500*1000)/(1000*1000);
    else
        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->pb_time= s->pp_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 */
    
    init_aspect_info(s);

    put_bits(&s->pb, 4, s->aspect_ratio_info);/* aspect ratio info */
    if (s->aspect_ratio_info == FF_ASPECT_EXTENDED)
    {
	put_bits(&s->pb, 8, s->aspected_width);
	put_bits(&s->pb, 8, s->aspected_height);
    }

    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, s->progressive_sequence ? 0 : 1);
    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 */
    }
    
    s->quant_precision=5;
    put_bits(&s->pb, 1, 0);		/* not 8 bit == false */
    put_bits(&s->pb, 1, s->mpeg_quant);	/* quant type= (0=h263 style)*/
    if(s->mpeg_quant) put_bits(&s->pb, 2, 0); /* no custom matrixes */

    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);

    /* user data */
    if(!ff_bit_exact){
        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);
    }
    
    s->partitioned_frame= s->data_partitioning && s->pict_type!=B_TYPE;

//printf("num:%d rate:%d base:%d\n", s->picture_number, s->frame_rate, FRAME_RATE_BASE);
    
    put_bits(&s->pb, 16, 0);	        /* vop header */
    put_bits(&s->pb, 16, 0x1B6);	/* vop header */
    put_bits(&s->pb, 2, s->pict_type - 1);	/* pict type: I = 0 , P = 1 */

    time_div= s->time/s->time_increment_resolution;
    time_mod= s->time%s->time_increment_resolution;
    time_incr= time_div - s->last_time_base;