int ff_h263_decode_frame(AVCodecContext *avctx,

                             void *data, int *got_frame,

                             AVPacket *avpkt)

{

    const uint8_t *buf = avpkt->data;

    int buf_size = avpkt->size;

    MpegEncContext *s = avctx->priv_data;

    int ret;

    AVFrame *pict = data;



    s->flags= avctx->flags;

    s->flags2= avctx->flags2;



    

    if (buf_size == 0) {

        

        if (s->low_delay==0 && s->next_picture_ptr) {

            if ((ret = av_frame_ref(pict, &s->next_picture_ptr->f)) < 0)

                return ret;

            s->next_picture_ptr= NULL;



            *got_frame = 1;

        }



        return 0;

    }



    if(s->flags&CODEC_FLAG_TRUNCATED){

        int next;



        if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4){

            next= ff_mpeg4_find_frame_end(&s->parse_context, buf, buf_size);

        }else if(CONFIG_H263_DECODER && s->codec_id==AV_CODEC_ID_H263){

            next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);

        }else if(CONFIG_H263P_DECODER && s->codec_id==AV_CODEC_ID_H263P){

            next= ff_h263_find_frame_end(&s->parse_context, buf, buf_size);

        }else{

            av_log(s->avctx, AV_LOG_ERROR, "this codec does not support truncated bitstreams\n");

            return AVERROR(EINVAL);

        }



        if( ff_combine_frame(&s->parse_context, next, (const uint8_t **)&buf, &buf_size) < 0 )

            return buf_size;

    }





retry:

    if(s->divx_packed && s->bitstream_buffer_size){

        int i;

        for(i=0; i<buf_size-3; i++){

            if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1){

                if(buf[i+3]==0xB0){

                    av_log(s->avctx, AV_LOG_WARNING, "Discarding excessive bitstream in packed xvid\n");

                    s->bitstream_buffer_size=0;

                }

                break;

            }

        }

    }



    if(s->bitstream_buffer_size && (s->divx_packed || buf_size<20)){ 

        init_get_bits(&s->gb, s->bitstream_buffer, s->bitstream_buffer_size*8);

    }else

        init_get_bits(&s->gb, buf, buf_size*8);

    s->bitstream_buffer_size=0;



    if (!s->context_initialized) {

        if ((ret = ff_MPV_common_init(s)) < 0) 

            return ret;

    }



    



    if (s->current_picture_ptr == NULL || s->current_picture_ptr->f.data[0]) {

        int i= ff_find_unused_picture(s, 0);

        if (i < 0)

            return i;

        s->current_picture_ptr= &s->picture[i];

    }



    

    if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5) {

        ret= ff_wmv2_decode_picture_header(s);

    } else if (CONFIG_MSMPEG4_DECODER && s->msmpeg4_version) {

        ret = ff_msmpeg4_decode_picture_header(s);

    } else if (CONFIG_MPEG4_DECODER && s->h263_pred) {

        if(s->avctx->extradata_size && s->picture_number==0){

            GetBitContext gb;



            init_get_bits(&gb, s->avctx->extradata, s->avctx->extradata_size*8);

            ret = ff_mpeg4_decode_picture_header(s, &gb);

        }

        ret = ff_mpeg4_decode_picture_header(s, &s->gb);

    } else if (CONFIG_H263I_DECODER && s->codec_id == AV_CODEC_ID_H263I) {

        ret = ff_intel_h263_decode_picture_header(s);

    } else if (CONFIG_FLV_DECODER && s->h263_flv) {

        ret = ff_flv_decode_picture_header(s);

    } else {

        ret = ff_h263_decode_picture_header(s);

    }



    if (ret < 0 || ret==FRAME_SKIPPED) {

        if (   s->width  != avctx->coded_width

            || s->height != avctx->coded_height) {

                av_log(s->avctx, AV_LOG_WARNING, "Reverting picture dimensions change due to header decoding failure\n");

                s->width = avctx->coded_width;

                s->height= avctx->coded_height;

        }

    }

    if(ret==FRAME_SKIPPED) return get_consumed_bytes(s, buf_size);



    

    if (ret < 0){

        av_log(s->avctx, AV_LOG_ERROR, "header damaged\n");

        return ret;

    }



    avctx->has_b_frames= !s->low_delay;



    if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){

        if(s->stream_codec_tag == AV_RL32("XVID") ||

           s->codec_tag == AV_RL32("XVID") || s->codec_tag == AV_RL32("XVIX") ||

           s->codec_tag == AV_RL32("RMP4") || s->codec_tag == AV_RL32("ZMP4") ||

           s->codec_tag == AV_RL32("SIPP")

           )

            s->xvid_build= 0;

#if 0

        if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==1

           && s->padding_bug_score > 0 && s->low_delay) 

            s->xvid_build= 0;

#endif

    }



    if(s->xvid_build==-1 && s->divx_version==-1 && s->lavc_build==-1){

        if(s->codec_tag == AV_RL32("DIVX") && s->vo_type==0 && s->vol_control_parameters==0)

            s->divx_version= 400; 

    }



    if(s->xvid_build>=0 && s->divx_version>=0){

        s->divx_version=

        s->divx_build= -1;

    }



    if(s->workaround_bugs&FF_BUG_AUTODETECT){

        if(s->codec_tag == AV_RL32("XVIX"))

            s->workaround_bugs|= FF_BUG_XVID_ILACE;



        if(s->codec_tag == AV_RL32("UMP4")){

            s->workaround_bugs|= FF_BUG_UMP4;

        }



        if(s->divx_version>=500 && s->divx_build<1814){

            s->workaround_bugs|= FF_BUG_QPEL_CHROMA;

        }



        if(s->divx_version>502 && s->divx_build<1814){

            s->workaround_bugs|= FF_BUG_QPEL_CHROMA2;

        }



        if(s->xvid_build<=3U)

            s->padding_bug_score= 256*256*256*64;



        if(s->xvid_build<=1U)

            s->workaround_bugs|= FF_BUG_QPEL_CHROMA;



        if(s->xvid_build<=12U)

            s->workaround_bugs|= FF_BUG_EDGE;



        if(s->xvid_build<=32U)

            s->workaround_bugs|= FF_BUG_DC_CLIP;



#define SET_QPEL_FUNC(postfix1, postfix2) \

    s->dsp.put_ ## postfix1 = ff_put_ ## postfix2;\

    s->dsp.put_no_rnd_ ## postfix1 = ff_put_no_rnd_ ## postfix2;\

    s->dsp.avg_ ## postfix1 = ff_avg_ ## postfix2;



        if(s->lavc_build<4653U)

            s->workaround_bugs|= FF_BUG_STD_QPEL;



        if(s->lavc_build<4655U)

            s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;



        if(s->lavc_build<4670U){

            s->workaround_bugs|= FF_BUG_EDGE;

        }



        if(s->lavc_build<=4712U)

            s->workaround_bugs|= FF_BUG_DC_CLIP;



        if(s->divx_version>=0)

            s->workaround_bugs|= FF_BUG_DIRECT_BLOCKSIZE;

        if(s->divx_version==501 && s->divx_build==20020416)

            s->padding_bug_score= 256*256*256*64;



        if(s->divx_version<500U){

            s->workaround_bugs|= FF_BUG_EDGE;

        }



        if(s->divx_version>=0)

            s->workaround_bugs|= FF_BUG_HPEL_CHROMA;

#if 0

        if(s->divx_version==500)

            s->padding_bug_score= 256*256*256*64;



        





        if(   s->resync_marker==0 && s->data_partitioning==0 && s->divx_version==-1

           && s->codec_id==AV_CODEC_ID_MPEG4 && s->vo_type==0)

            s->workaround_bugs|= FF_BUG_NO_PADDING;



        if(s->lavc_build<4609U) 

            s->workaround_bugs|= FF_BUG_NO_PADDING;

#endif

    }



    if(s->workaround_bugs& FF_BUG_STD_QPEL){

        SET_QPEL_FUNC(qpel_pixels_tab[0][ 5], qpel16_mc11_old_c)

        SET_QPEL_FUNC(qpel_pixels_tab[0][ 7], qpel16_mc31_old_c)

        SET_QPEL_FUNC(qpel_pixels_tab[0][ 9], qpel16_mc12_old_c)

        SET_QPEL_FUNC(qpel_pixels_tab[0][11], qpel16_mc32_old_c)

        SET_QPEL_FUNC(qpel_pixels_tab[0][13], qpel16_mc13_old_c)

        SET_QPEL_FUNC(qpel_pixels_tab[0][15], qpel16_mc33_old_c)



        SET_QPEL_FUNC(qpel_pixels_tab[1][ 5], qpel8_mc11_old_c)

        SET_QPEL_FUNC(qpel_pixels_tab[1][ 7], qpel8_mc31_old_c)

        SET_QPEL_FUNC(qpel_pixels_tab[1][ 9], qpel8_mc12_old_c)

        SET_QPEL_FUNC(qpel_pixels_tab[1][11], qpel8_mc32_old_c)

        SET_QPEL_FUNC(qpel_pixels_tab[1][13], qpel8_mc13_old_c)

        SET_QPEL_FUNC(qpel_pixels_tab[1][15], qpel8_mc33_old_c)

    }



    if(avctx->debug & FF_DEBUG_BUGS)

        av_log(s->avctx, AV_LOG_DEBUG, "bugs: %X lavc_build:%d xvid_build:%d divx_version:%d divx_build:%d %s\n",

               s->workaround_bugs, s->lavc_build, s->xvid_build, s->divx_version, s->divx_build,

               s->divx_packed ? "p" : "");



#if HAVE_MMX

    if (s->codec_id == AV_CODEC_ID_MPEG4 && s->xvid_build>=0 && avctx->idct_algo == FF_IDCT_AUTO && (av_get_cpu_flags() & AV_CPU_FLAG_MMX)) {

        avctx->idct_algo= FF_IDCT_XVIDMMX;

        ff_dct_common_init(s);

        goto retry;

    }

#endif



        

        

        

        



    if (s->width  != avctx->coded_width  ||

        s->height != avctx->coded_height ||

        s->context_reinit) {

        

        s->context_reinit = 0;



        avcodec_set_dimensions(avctx, s->width, s->height);



        if ((ret = ff_MPV_common_frame_size_change(s)))

            return ret;

    }



    if((s->codec_id==AV_CODEC_ID_H263 || s->codec_id==AV_CODEC_ID_H263P || s->codec_id == AV_CODEC_ID_H263I))

        s->gob_index = ff_h263_get_gob_height(s);



    

    s->current_picture.f.pict_type = s->pict_type;

    s->current_picture.f.key_frame = s->pict_type == AV_PICTURE_TYPE_I;



    

    if (s->last_picture_ptr == NULL &&

        (s->pict_type == AV_PICTURE_TYPE_B || s->droppable))

        return get_consumed_bytes(s, buf_size);

    if(   (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==AV_PICTURE_TYPE_B)

       || (avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=AV_PICTURE_TYPE_I)

       ||  avctx->skip_frame >= AVDISCARD_ALL)

        return get_consumed_bytes(s, buf_size);



    if(s->next_p_frame_damaged){

        if(s->pict_type==AV_PICTURE_TYPE_B)

            return get_consumed_bytes(s, buf_size);

        else

            s->next_p_frame_damaged=0;

    }



    if((!s->no_rounding) || s->pict_type==AV_PICTURE_TYPE_B){

        s->me.qpel_put= s->dsp.put_qpel_pixels_tab;

        s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;

    }else{

        s->me.qpel_put= s->dsp.put_no_rnd_qpel_pixels_tab;

        s->me.qpel_avg= s->dsp.avg_qpel_pixels_tab;

    }



    if ((ret = ff_MPV_frame_start(s, avctx)) < 0)

        return ret;



    if (!s->divx_packed && !avctx->hwaccel)

        ff_thread_finish_setup(avctx);



    if (CONFIG_MPEG4_VDPAU_DECODER && (s->avctx->codec->capabilities & CODEC_CAP_HWACCEL_VDPAU)) {

        ff_vdpau_mpeg4_decode_picture(s, s->gb.buffer, s->gb.buffer_end - s->gb.buffer);

        goto frame_end;

    }



    if (avctx->hwaccel) {

        if ((ret = avctx->hwaccel->start_frame(avctx, s->gb.buffer, s->gb.buffer_end - s->gb.buffer)) < 0)

            return ret;

    }



    ff_mpeg_er_frame_start(s);



    

    

    if (CONFIG_WMV2_DECODER && s->msmpeg4_version==5){

        ret = ff_wmv2_decode_secondary_picture_header(s);

        if(ret<0) return ret;

        if(ret==1) goto frame_end;

    }



    

    s->mb_x=0;

    s->mb_y=0;



    ret = decode_slice(s);

    while(s->mb_y<s->mb_height){

        if(s->msmpeg4_version){

            if(s->slice_height==0 || s->mb_x!=0 || (s->mb_y%s->slice_height)!=0 || get_bits_left(&s->gb)<0)

                break;

        }else{

            int prev_x=s->mb_x, prev_y=s->mb_y;

            if(ff_h263_resync(s)<0)

                break;

            if (prev_y * s->mb_width + prev_x < s->mb_y * s->mb_width + s->mb_x)

                s->er.error_occurred = 1;

        }



        if(s->msmpeg4_version<4 && s->h263_pred)

            ff_mpeg4_clean_buffers(s);



        if (decode_slice(s) < 0) ret = AVERROR_INVALIDDATA;

    }



    if (s->msmpeg4_version && s->msmpeg4_version<4 && s->pict_type==AV_PICTURE_TYPE_I)

        if(!CONFIG_MSMPEG4_DECODER || ff_msmpeg4_decode_ext_header(s, buf_size) < 0){

            s->er.error_status_table[s->mb_num - 1] = ER_MB_ERROR;

        }



    av_assert1(s->bitstream_buffer_size==0);

frame_end:

    ff_er_frame_end(&s->er);



    if (avctx->hwaccel) {

        if ((ret = avctx->hwaccel->end_frame(avctx)) < 0)

            return ret;

    }



    ff_MPV_frame_end(s);



    

    



    if(s->codec_id==AV_CODEC_ID_MPEG4 && s->divx_packed){

        int current_pos= s->gb.buffer == s->bitstream_buffer ? 0 : (get_bits_count(&s->gb)>>3);

        int startcode_found=0;



        if(buf_size - current_pos > 7){

            int i;

            for(i=current_pos; i<buf_size-4; i++){

                if(buf[i]==0 && buf[i+1]==0 && buf[i+2]==1 && buf[i+3]==0xB6){

                    startcode_found=!(buf[i+4]&0x40);

                    break;

                }

            }

        }



        if(startcode_found){

            av_fast_malloc(

                &s->bitstream_buffer,

                &s->allocated_bitstream_buffer_size,

                buf_size - current_pos + FF_INPUT_BUFFER_PADDING_SIZE);

            if (!s->bitstream_buffer)

                return AVERROR(ENOMEM);

            memcpy(s->bitstream_buffer, buf + current_pos, buf_size - current_pos);

            s->bitstream_buffer_size= buf_size - current_pos;

        }

    }



    if (!s->divx_packed && avctx->hwaccel)

        ff_thread_finish_setup(avctx);



    av_assert1(s->current_picture.f.pict_type == s->current_picture_ptr->f.pict_type);

    av_assert1(s->current_picture.f.pict_type == s->pict_type);

    if (s->pict_type == AV_PICTURE_TYPE_B || s->low_delay) {

        if ((ret = av_frame_ref(pict, &s->current_picture_ptr->f)) < 0)

            return ret;

        ff_print_debug_info(s, s->current_picture_ptr, pict);

        ff_mpv_export_qp_table(s, pict, s->current_picture_ptr, FF_QSCALE_TYPE_MPEG1);

    } else if (s->last_picture_ptr != NULL) {

        if ((ret = av_frame_ref(pict, &s->last_picture_ptr->f)) < 0)

            return ret;

        ff_print_debug_info(s, s->last_picture_ptr, pict);

        ff_mpv_export_qp_table(s, pict, s->last_picture_ptr, FF_QSCALE_TYPE_MPEG1);

    }



    if(s->last_picture_ptr || s->low_delay){

        if (   pict->format == AV_PIX_FMT_YUV420P

            && (s->codec_tag == AV_RL32("GEOV") || s->codec_tag == AV_RL32("GEOX"))) {

            int x, y, p;

            av_frame_make_writable(pict);

            for (p=0; p<3; p++) {

                int w = FF_CEIL_RSHIFT(pict-> width, !!p);

                int h = FF_CEIL_RSHIFT(pict->height, !!p);

                int linesize = pict->linesize[p];

                for (y=0; y<(h>>1); y++)

                    for (x=0; x<w; x++)

                        FFSWAP(int,

                               pict->data[p][x + y*linesize],

                               pict->data[p][x + (h-1-y)*linesize]);

            }

        }

        *got_frame = 1;

    }



    return (ret && (avctx->err_recognition & AV_EF_EXPLODE))?ret:get_consumed_bytes(s, buf_size);

}
