rv10.c

/*
 * RV10 codec
 * Copyright (c) 2000,2001 Fabrice Bellard.
 *
 * 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
 */

/**
 * @file rv10.c
 * RV10 codec.
 */
 
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"

//#define DEBUG

#define DC_VLC_BITS 14 //FIXME find a better solution

static const uint16_t rv_lum_code[256] =
{
 0x3e7f, 0x0f00, 0x0f01, 0x0f02, 0x0f03, 0x0f04, 0x0f05, 0x0f06,
 0x0f07, 0x0f08, 0x0f09, 0x0f0a, 0x0f0b, 0x0f0c, 0x0f0d, 0x0f0e,
 0x0f0f, 0x0f10, 0x0f11, 0x0f12, 0x0f13, 0x0f14, 0x0f15, 0x0f16,
 0x0f17, 0x0f18, 0x0f19, 0x0f1a, 0x0f1b, 0x0f1c, 0x0f1d, 0x0f1e,
 0x0f1f, 0x0f20, 0x0f21, 0x0f22, 0x0f23, 0x0f24, 0x0f25, 0x0f26,
 0x0f27, 0x0f28, 0x0f29, 0x0f2a, 0x0f2b, 0x0f2c, 0x0f2d, 0x0f2e,
 0x0f2f, 0x0f30, 0x0f31, 0x0f32, 0x0f33, 0x0f34, 0x0f35, 0x0f36,
 0x0f37, 0x0f38, 0x0f39, 0x0f3a, 0x0f3b, 0x0f3c, 0x0f3d, 0x0f3e,
 0x0f3f, 0x0380, 0x0381, 0x0382, 0x0383, 0x0384, 0x0385, 0x0386,
 0x0387, 0x0388, 0x0389, 0x038a, 0x038b, 0x038c, 0x038d, 0x038e,
 0x038f, 0x0390, 0x0391, 0x0392, 0x0393, 0x0394, 0x0395, 0x0396,
 0x0397, 0x0398, 0x0399, 0x039a, 0x039b, 0x039c, 0x039d, 0x039e,
 0x039f, 0x00c0, 0x00c1, 0x00c2, 0x00c3, 0x00c4, 0x00c5, 0x00c6,
 0x00c7, 0x00c8, 0x00c9, 0x00ca, 0x00cb, 0x00cc, 0x00cd, 0x00ce,
 0x00cf, 0x0050, 0x0051, 0x0052, 0x0053, 0x0054, 0x0055, 0x0056,
 0x0057, 0x0020, 0x0021, 0x0022, 0x0023, 0x000c, 0x000d, 0x0004,
 0x0000, 0x0005, 0x000e, 0x000f, 0x0024, 0x0025, 0x0026, 0x0027,
 0x0058, 0x0059, 0x005a, 0x005b, 0x005c, 0x005d, 0x005e, 0x005f,
 0x00d0, 0x00d1, 0x00d2, 0x00d3, 0x00d4, 0x00d5, 0x00d6, 0x00d7,
 0x00d8, 0x00d9, 0x00da, 0x00db, 0x00dc, 0x00dd, 0x00de, 0x00df,
 0x03a0, 0x03a1, 0x03a2, 0x03a3, 0x03a4, 0x03a5, 0x03a6, 0x03a7,
 0x03a8, 0x03a9, 0x03aa, 0x03ab, 0x03ac, 0x03ad, 0x03ae, 0x03af,
 0x03b0, 0x03b1, 0x03b2, 0x03b3, 0x03b4, 0x03b5, 0x03b6, 0x03b7,
 0x03b8, 0x03b9, 0x03ba, 0x03bb, 0x03bc, 0x03bd, 0x03be, 0x03bf,
 0x0f40, 0x0f41, 0x0f42, 0x0f43, 0x0f44, 0x0f45, 0x0f46, 0x0f47,
 0x0f48, 0x0f49, 0x0f4a, 0x0f4b, 0x0f4c, 0x0f4d, 0x0f4e, 0x0f4f,
 0x0f50, 0x0f51, 0x0f52, 0x0f53, 0x0f54, 0x0f55, 0x0f56, 0x0f57,
 0x0f58, 0x0f59, 0x0f5a, 0x0f5b, 0x0f5c, 0x0f5d, 0x0f5e, 0x0f5f,
 0x0f60, 0x0f61, 0x0f62, 0x0f63, 0x0f64, 0x0f65, 0x0f66, 0x0f67,
 0x0f68, 0x0f69, 0x0f6a, 0x0f6b, 0x0f6c, 0x0f6d, 0x0f6e, 0x0f6f,
 0x0f70, 0x0f71, 0x0f72, 0x0f73, 0x0f74, 0x0f75, 0x0f76, 0x0f77,
 0x0f78, 0x0f79, 0x0f7a, 0x0f7b, 0x0f7c, 0x0f7d, 0x0f7e, 0x0f7f,
};

static const uint8_t rv_lum_bits[256] = 
{
 14, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 10, 10, 10, 10, 10, 10, 10,
 10, 10, 10, 10, 10, 10, 10, 10,
 10, 10, 10, 10, 10, 10, 10, 10,
 10, 10, 10, 10, 10, 10, 10, 10,
 10,  8,  8,  8,  8,  8,  8,  8,
  8,  8,  8,  8,  8,  8,  8,  8,
  8,  7,  7,  7,  7,  7,  7,  7,
  7,  6,  6,  6,  6,  5,  5,  4,
  2,  4,  5,  5,  6,  6,  6,  6,
  7,  7,  7,  7,  7,  7,  7,  7,
  8,  8,  8,  8,  8,  8,  8,  8,
  8,  8,  8,  8,  8,  8,  8,  8,
 10, 10, 10, 10, 10, 10, 10, 10,
 10, 10, 10, 10, 10, 10, 10, 10,
 10, 10, 10, 10, 10, 10, 10, 10,
 10, 10, 10, 10, 10, 10, 10, 10,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
};

static const uint16_t rv_chrom_code[256] =
{
 0xfe7f, 0x3f00, 0x3f01, 0x3f02, 0x3f03, 0x3f04, 0x3f05, 0x3f06,
 0x3f07, 0x3f08, 0x3f09, 0x3f0a, 0x3f0b, 0x3f0c, 0x3f0d, 0x3f0e,
 0x3f0f, 0x3f10, 0x3f11, 0x3f12, 0x3f13, 0x3f14, 0x3f15, 0x3f16,
 0x3f17, 0x3f18, 0x3f19, 0x3f1a, 0x3f1b, 0x3f1c, 0x3f1d, 0x3f1e,
 0x3f1f, 0x3f20, 0x3f21, 0x3f22, 0x3f23, 0x3f24, 0x3f25, 0x3f26,
 0x3f27, 0x3f28, 0x3f29, 0x3f2a, 0x3f2b, 0x3f2c, 0x3f2d, 0x3f2e,
 0x3f2f, 0x3f30, 0x3f31, 0x3f32, 0x3f33, 0x3f34, 0x3f35, 0x3f36,
 0x3f37, 0x3f38, 0x3f39, 0x3f3a, 0x3f3b, 0x3f3c, 0x3f3d, 0x3f3e,
 0x3f3f, 0x0f80, 0x0f81, 0x0f82, 0x0f83, 0x0f84, 0x0f85, 0x0f86,
 0x0f87, 0x0f88, 0x0f89, 0x0f8a, 0x0f8b, 0x0f8c, 0x0f8d, 0x0f8e,
 0x0f8f, 0x0f90, 0x0f91, 0x0f92, 0x0f93, 0x0f94, 0x0f95, 0x0f96,
 0x0f97, 0x0f98, 0x0f99, 0x0f9a, 0x0f9b, 0x0f9c, 0x0f9d, 0x0f9e,
 0x0f9f, 0x03c0, 0x03c1, 0x03c2, 0x03c3, 0x03c4, 0x03c5, 0x03c6,
 0x03c7, 0x03c8, 0x03c9, 0x03ca, 0x03cb, 0x03cc, 0x03cd, 0x03ce,
 0x03cf, 0x00e0, 0x00e1, 0x00e2, 0x00e3, 0x00e4, 0x00e5, 0x00e6,
 0x00e7, 0x0030, 0x0031, 0x0032, 0x0033, 0x0008, 0x0009, 0x0002,
 0x0000, 0x0003, 0x000a, 0x000b, 0x0034, 0x0035, 0x0036, 0x0037,
 0x00e8, 0x00e9, 0x00ea, 0x00eb, 0x00ec, 0x00ed, 0x00ee, 0x00ef,
 0x03d0, 0x03d1, 0x03d2, 0x03d3, 0x03d4, 0x03d5, 0x03d6, 0x03d7,
 0x03d8, 0x03d9, 0x03da, 0x03db, 0x03dc, 0x03dd, 0x03de, 0x03df,
 0x0fa0, 0x0fa1, 0x0fa2, 0x0fa3, 0x0fa4, 0x0fa5, 0x0fa6, 0x0fa7,
 0x0fa8, 0x0fa9, 0x0faa, 0x0fab, 0x0fac, 0x0fad, 0x0fae, 0x0faf,
 0x0fb0, 0x0fb1, 0x0fb2, 0x0fb3, 0x0fb4, 0x0fb5, 0x0fb6, 0x0fb7,
 0x0fb8, 0x0fb9, 0x0fba, 0x0fbb, 0x0fbc, 0x0fbd, 0x0fbe, 0x0fbf,
 0x3f40, 0x3f41, 0x3f42, 0x3f43, 0x3f44, 0x3f45, 0x3f46, 0x3f47,
 0x3f48, 0x3f49, 0x3f4a, 0x3f4b, 0x3f4c, 0x3f4d, 0x3f4e, 0x3f4f,
 0x3f50, 0x3f51, 0x3f52, 0x3f53, 0x3f54, 0x3f55, 0x3f56, 0x3f57,
 0x3f58, 0x3f59, 0x3f5a, 0x3f5b, 0x3f5c, 0x3f5d, 0x3f5e, 0x3f5f,
 0x3f60, 0x3f61, 0x3f62, 0x3f63, 0x3f64, 0x3f65, 0x3f66, 0x3f67,
 0x3f68, 0x3f69, 0x3f6a, 0x3f6b, 0x3f6c, 0x3f6d, 0x3f6e, 0x3f6f,
 0x3f70, 0x3f71, 0x3f72, 0x3f73, 0x3f74, 0x3f75, 0x3f76, 0x3f77,
 0x3f78, 0x3f79, 0x3f7a, 0x3f7b, 0x3f7c, 0x3f7d, 0x3f7e, 0x3f7f,
};

static const uint8_t rv_chrom_bits[256] =
{
 16, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14,
 14, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 10, 10, 10, 10, 10, 10, 10,
 10, 10, 10, 10, 10, 10, 10, 10,
 10,  8,  8,  8,  8,  8,  8,  8,
  8,  6,  6,  6,  6,  4,  4,  3,
  2,  3,  4,  4,  6,  6,  6,  6,
  8,  8,  8,  8,  8,  8,  8,  8,
 10, 10, 10, 10, 10, 10, 10, 10,
 10, 10, 10, 10, 10, 10, 10, 10,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 12, 12, 12, 12, 12, 12, 12, 12,
 14, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14,
 14, 14, 14, 14, 14, 14, 14, 14,
};

static VLC rv_dc_lum, rv_dc_chrom;

int rv_decode_dc(MpegEncContext *s, int n)
{
    int code;

    if (n < 4) {
        code = get_vlc2(&s->gb, rv_dc_lum.table, DC_VLC_BITS, 2);
        if (code < 0) {
            /* XXX: I don't understand why they use LONGER codes than
               necessary. The following code would be completely useless
               if they had thought about it !!! */
            code = get_bits(&s->gb, 7);
            if (code == 0x7c) {
                code = (int8_t)(get_bits(&s->gb, 7) + 1);
            } else if (code == 0x7d) {
                code = -128 + get_bits(&s->gb, 7);
            } else if (code == 0x7e) {
                if (get_bits(&s->gb, 1) == 0)
                    code = (int8_t)(get_bits(&s->gb, 8) + 1);
                else
                    code = (int8_t)(get_bits(&s->gb, 8));
            } else if (code == 0x7f) {
                get_bits(&s->gb, 11);
                code = 1;
            }
        } else {
            code -= 128;
        }
    } else {
        code = get_vlc2(&s->gb, rv_dc_chrom.table, DC_VLC_BITS, 2);
        /* same remark */
        if (code < 0) {
            code = get_bits(&s->gb, 9);
            if (code == 0x1fc) {
                code = (int8_t)(get_bits(&s->gb, 7) + 1);
            } else if (code == 0x1fd) {
                code = -128 + get_bits(&s->gb, 7);
            } else if (code == 0x1fe) {
                get_bits(&s->gb, 9);
                code = 1;
            } else {
                av_log(s->avctx, AV_LOG_ERROR, "chroma dc error\n");
                return 0xffff;
            }
        } else {
            code -= 128;
        }
    }
    return -code;
}

#ifdef CONFIG_ENCODERS

/* write RV 1.0 compatible frame header */
void rv10_encode_picture_header(MpegEncContext *s, int picture_number)
{
    int full_frame= 0;

    align_put_bits(&s->pb);
    
    put_bits(&s->pb, 1, 1);	/* marker */

    put_bits(&s->pb, 1, (s->pict_type == P_TYPE));

    put_bits(&s->pb, 1, 0);	/* not PB frame */

    put_bits(&s->pb, 5, s->qscale);

    if (s->pict_type == I_TYPE) {
	/* specific MPEG like DC coding not used */
    }
    /* if multiple packets per frame are sent, the position at which
       to display the macro blocks is coded here */
    if(!full_frame){
        put_bits(&s->pb, 6, 0);	/* mb_x */
        put_bits(&s->pb, 6, 0);	/* mb_y */
        put_bits(&s->pb, 12, s->mb_width * s->mb_height);
    }

    put_bits(&s->pb, 3, 0);	/* ignored */
}

static int get_num(GetBitContext *gb)
{
    int n, n1;

    n = get_bits(gb, 16);
    if (n >= 0x4000) {
        return n - 0x4000;
    } else {
        n1 = get_bits(gb, 16);
        return (n << 16) | n1;
    }
}

#endif //CONFIG_ENCODERS

/* read RV 1.0 compatible frame header */
static int rv10_decode_picture_header(MpegEncContext *s)
{
    int mb_count, pb_frame, marker, full_frame, unk;
    
    full_frame= s->avctx->slice_count==1;
//printf("ff:%d\n", full_frame);
    marker = get_bits(&s->gb, 1);

    if (get_bits(&s->gb, 1))
        s->pict_type = P_TYPE;
    else
        s->pict_type = I_TYPE;
//printf("h:%X ver:%d\n",h,s->rv10_version);
    if(!marker) av_log(s->avctx, AV_LOG_ERROR, "marker missing\n");
    pb_frame = get_bits(&s->gb, 1);

#ifdef DEBUG
    printf("pict_type=%d pb_frame=%d\n", s->pict_type, pb_frame);
#endif
    
    if (pb_frame){
        av_log(s->avctx, AV_LOG_ERROR, "pb frame not supported\n");
        return -1;
    }

    s->qscale = get_bits(&s->gb, 5);
    if(s->qscale==0){
        av_log(s->avctx, AV_LOG_ERROR, "error, qscale:0\n");
        return -1;
    }

    if (s->pict_type == I_TYPE) {
        if (s->rv10_version == 3) {
            /* specific MPEG like DC coding not used */
            s->last_dc[0] = get_bits(&s->gb, 8);
            s->last_dc[1] = get_bits(&s->gb, 8);
            s->last_dc[2] = get_bits(&s->gb, 8);
#ifdef DEBUG
            printf("DC:%d %d %d\n",
                   s->last_dc[0],
                   s->last_dc[1],
                   s->last_dc[2]);
#endif
        }
    }
    /* if multiple packets per frame are sent, the position at which
       to display the macro blocks is coded here */
    if ((!full_frame) || show_bits(&s->gb, 12)==0) {
        s->mb_x = get_bits(&s->gb, 6);	/* mb_x */
        s->mb_y = get_bits(&s->gb, 6);	/* mb_y */
        mb_count = get_bits(&s->gb, 12);
    } else {
        s->mb_x = 0;
        s->mb_y = 0;
        mb_count = s->mb_width * s->mb_height;
    }
    unk= get_bits(&s->gb, 3);	/* ignored */
//printf("%d\n", unk);
    s->f_code = 1;
    s->unrestricted_mv = 1;

    return mb_count;
}

static int rv20_decode_picture_header(MpegEncContext *s)
{
    int seq, mb_pos, i;
    
    if(s->avctx->sub_id == 0x30202002 || s->avctx->sub_id == 0x30203002){
        if (get_bits(&s->gb, 3)){
            av_log(s->avctx, AV_LOG_ERROR, "unknown triplet set\n");
            return -1;
        } 
    }   

    i= get_bits(&s->gb, 2);
    switch(i){
    case 0: s->pict_type= I_TYPE; break;
    case 1: s->pict_type= I_TYPE; break; //hmm ...
    case 2: s->pict_type= P_TYPE; break;
    case 3: s->pict_type= B_TYPE; break;
    default: 
        av_log(s->avctx, AV_LOG_ERROR, "unknown frame type\n");
        return -1;
    }
    
    if (get_bits(&s->gb, 1)){
        av_log(s->avctx, AV_LOG_ERROR, "unknown bit set\n");
        return -1;
    }

    s->qscale = get_bits(&s->gb, 5);
    if(s->qscale==0){
        av_log(s->avctx, AV_LOG_ERROR, "error, qscale:0\n");
        return -1;
    }
    if(s->avctx->sub_id == 0x30203002){
        if (get_bits(&s->gb, 1)){
            av_log(s->avctx, AV_LOG_ERROR, "unknown bit2 set\n");
            return -1;
        }
    }
        
    if(s->avctx->has_b_frames){
        if (get_bits(&s->gb, 1)){
            av_log(s->avctx, AV_LOG_ERROR, "unknown bit3 set\n");
//            return -1;
        }
        seq= get_bits(&s->gb, 15);
    }else
        seq= get_bits(&s->gb, 8)*128;
//printf("%d\n", seq);
    seq |= s->time &~0x7FFF;
    if(seq - s->time >  0x4000) seq -= 0x8000;
    if(seq - s->time < -0x4000) seq += 0x8000;
    if(seq != s->time){  
        if(s->pict_type!=B_TYPE){
            s->time= seq;
            s->pp_time= s->time - s->last_non_b_time;
            s->last_non_b_time= s->time;
        }else{
            s->time= seq;
            s->pb_time= s->pp_time - (s->last_non_b_time - s->time);
            if(s->pp_time <=s->pb_time || s->pp_time <= s->pp_time - s->pb_time || s->pp_time<=0){
                printf("messed up order, seeking?, skiping current b frame\n");
                return FRAME_SKIPED;
            }
        }
    }
//    printf("%d %d %d %d %d\n", seq, (int)s->time, (int)s->last_non_b_time, s->pp_time, s->pb_time);

    mb_pos= ff_h263_decode_mba(s);
    s->no_rounding= get_bits1(&s->gb);
    
    s->f_code = 1;
    s->unrestricted_mv = 1;
    s->h263_aic= s->pict_type == I_TYPE;
//    s->alt_inter_vlc=1;
//    s->obmc=1;
//    s->umvplus=1;
    s->modified_quant=1;
    s->loop_filter=1;
    
    if(s->avctx->debug & FF_DEBUG_PICT_INFO){
            av_log(s->avctx, AV_LOG_INFO, "num:%5d x:%2d y:%2d type:%d qscale:%2d rnd:%d\n", 
                   seq, s->mb_x, s->mb_y, s->pict_type, s->qscale, s->no_rounding);
    }

    assert(s->pict_type != B_TYPE || !s->low_delay);

    return s->mb_width*s->mb_height - mb_pos;
}

static int rv10_decode_init(AVCodecContext *avctx)
{
    MpegEncContext *s = avctx->priv_data;
    static int done=0;

    s->avctx= avctx;
    s->out_format = FMT_H263;
    s->codec_id= avctx->codec_id;

    s->width = avctx->width;
    s->height = avctx->height;

    switch(avctx->sub_id){
    case 0x10000000:
        s->rv10_version= 0;
        s->h263_long_vectors=0;
        s->low_delay=1;
        break;
    case 0x10003000:
        s->rv10_version= 3;
        s->h263_long_vectors=1;
        s->low_delay=1;
        break;
    case 0x10003001:
        s->rv10_version= 3;
        s->h263_long_vectors=0;
        s->low_delay=1;
        break;
    case 0x20001000:
    case 0x20100001:
    case 0x20101001:
        s->low_delay=1;
        break;
    case 0x20200002:
    case 0x30202002:
    case 0x30203002:
        s->low_delay=0;
        s->avctx->has_b_frames=1;
        break;
    default:
        av_log(s->avctx, AV_LOG_ERROR, "unknown header %X\n", avctx->sub_id);
    }
//printf("ver:%X\n", avctx->sub_id);
    s->flags= avctx->flags;

    if (MPV_common_init(s) < 0)
        return -1;

    h263_decode_init_vlc(s);

    s->progressive_sequence=1;

    /* init rv vlc */
    if (!done) {
        init_vlc(&rv_dc_lum, DC_VLC_BITS, 256, 
                 rv_lum_bits, 1, 1,
                 rv_lum_code, 2, 2);
        init_vlc(&rv_dc_chrom, DC_VLC_BITS, 256, 
                 rv_chrom_bits, 1, 1,
                 rv_chrom_code, 2, 2);
        done = 1;
    }
    
    avctx->pix_fmt = PIX_FMT_YUV420P;

    return 0;
}

static int rv10_decode_end(AVCodecContext *avctx)
{
    MpegEncContext *s = avctx->priv_data;

    MPV_common_end(s);
    return 0;
}

static int rv10_decode_packet(AVCodecContext *avctx, 
                             uint8_t *buf, int buf_size)
{
    MpegEncContext *s = avctx->priv_data;
    int i, mb_count, mb_pos, left;

    init_get_bits(&s->gb, buf, buf_size*8);
#if 0
    for(i=0; i<buf_size*8 && i<200; i++)
        printf("%d", get_bits1(&s->gb));
    printf("\n");
    return 0;
#endif
    if(s->codec_id ==CODEC_ID_RV10)
        mb_count = rv10_decode_picture_header(s);
    else
        mb_count = rv20_decode_picture_header(s);
    if (mb_count < 0) {
        av_log(s->avctx, AV_LOG_ERROR, "HEADER ERROR\n");
        return -1;
    }
    
    if (s->mb_x >= s->mb_width ||
        s->mb_y >= s->mb_height) {
        av_log(s->avctx, AV_LOG_ERROR, "POS ERROR %d %d\n", s->mb_x, s->mb_y);
        return -1;
    }
    mb_pos = s->mb_y * s->mb_width + s->mb_x;
    left = s->mb_width * s->mb_height - mb_pos;
    if (mb_count > left) {
        av_log(s->avctx, AV_LOG_ERROR, "COUNT ERROR\n");
        return -1;
    }
//if(s->pict_type == P_TYPE) return 0;

    if ((s->mb_x == 0 && s->mb_y == 0) || s->current_picture_ptr==NULL) {
        if(MPV_frame_start(s, avctx) < 0)
            return -1;
    }

#ifdef DEBUG
    printf("qscale=%d\n", s->qscale);
#endif

    /* default quantization values */
    if(s->codec_id== CODEC_ID_RV10){
        if(s->mb_y==0) s->first_slice_line=1;
    }else{
        s->first_slice_line=1;    
        s->resync_mb_x= s->mb_x;
        s->resync_mb_y= s->mb_y;
    }
    if(s->h263_aic){
        s->y_dc_scale_table= 
        s->c_dc_scale_table= ff_aic_dc_scale_table;
    }else{
        s->y_dc_scale_table=
        s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
    }

    if(s->modified_quant)
        s->chroma_qscale_table= ff_h263_chroma_qscale_table;
        
    ff_set_qscale(s, s->qscale);

    s->rv10_first_dc_coded[0] = 0;
    s->rv10_first_dc_coded[1] = 0;
    s->rv10_first_dc_coded[2] = 0;

    s->block_wrap[0]=
    s->block_wrap[1]=
    s->block_wrap[2]=
    s->block_wrap[3]= s->mb_width*2 + 2;
    s->block_wrap[4]=
    s->block_wrap[5]= s->mb_width + 2;
    ff_init_block_index(s);
    /* decode each macroblock */
    for(i=0;i<mb_count;i++) {
        int ret;
        ff_update_block_index(s);
#ifdef DEBUG
        printf("**mb x=%d y=%d\n", s->mb_x, s->mb_y);
#endif
        
	s->dsp.clear_blocks(s->block[0]);
        s->mv_dir = MV_DIR_FORWARD;
        s->mv_type = MV_TYPE_16X16; 
        ret=ff_h263_decode_mb(s, s->block);

        if (ret == SLICE_ERROR) {
            av_log(s->avctx, AV_LOG_ERROR, "ERROR at MB %d %d\n", s->mb_x, s->mb_y);
            return -1;
        }
        ff_h263_update_motion_val(s);
        MPV_decode_mb(s, s->block);
        if(s->loop_filter)
            ff_h263_loop_filter(s);

        if (++s->mb_x == s->mb_width) {
            s->mb_x = 0;
            s->mb_y++;
            ff_init_block_index(s);
        }
        if(s->mb_x == s->resync_mb_x)
            s->first_slice_line=0;
        if(ret == SLICE_END) break;
    }

    return buf_size;
}

static int rv10_decode_frame(AVCodecContext *avctx, 
                             void *data, int *data_size,
                             uint8_t *buf, int buf_size)
{
    MpegEncContext *s = avctx->priv_data;
    int i;
    AVFrame *pict = data; 

#ifdef DEBUG
    printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
#endif

    /* no supplementary picture */
    if (buf_size == 0) {
        *data_size = 0;
        return 0;
    }
    
    if(avctx->slice_count){
        for(i=0; i<avctx->slice_count; i++){
            int offset= avctx->slice_offset[i];
            int size;
            
            if(i+1 == avctx->slice_count)
                size= buf_size - offset;
            else
                size= avctx->slice_offset[i+1] - offset;

            if( rv10_decode_packet(avctx, buf+offset, size) < 0 )
                return -1;
        }
    }else{
        if( rv10_decode_packet(avctx, buf, buf_size) < 0 )
            return -1;
    }

    if(s->mb_y>=s->mb_height){
        MPV_frame_end(s);
    
        if(s->pict_type==B_TYPE || s->low_delay){
            *pict= *(AVFrame*)&s->current_picture;
            ff_print_debug_info(s, s->current_picture_ptr);
        } else {
            *pict= *(AVFrame*)&s->last_picture;
            ff_print_debug_info(s, s->last_picture_ptr);
        }
        
        *data_size = sizeof(AVFrame);
    }else{
        *data_size = 0;
    }

    return buf_size;
}

AVCodec rv10_decoder = {
    "rv10",
    CODEC_TYPE_VIDEO,
    CODEC_ID_RV10,
    sizeof(MpegEncContext),
    rv10_decode_init,
    NULL,
    rv10_decode_end,
    rv10_decode_frame,
    CODEC_CAP_DR1
};

AVCodec rv20_decoder = {
    "rv20",
    CODEC_TYPE_VIDEO,
    CODEC_ID_RV20,
    sizeof(MpegEncContext),
    rv10_decode_init,
    NULL,
    rv10_decode_end,
    rv10_decode_frame,
    CODEC_CAP_DR1
};