ffv1.c

                return AVERROR(ENOMEM);
        }
    }
    if(avctx->stats_in){
        char *p= avctx->stats_in;
        uint8_t best_state[256][256];
        int gob_count=0;
        char *next;

        av_assert0(s->version>=2);

        for(;;){
            for(j=0; j<256; j++){
                for(i=0; i<2; i++){
                    s->rc_stat[j][i]= strtol(p, &next, 0);
                    if(next==p){
                        av_log(avctx, AV_LOG_ERROR, "2Pass file invalid at %d %d [%s]\n", j,i,p);
                        return -1;
                    }
                    p=next;
                }
            }
            for(i=0; i<s->quant_table_count; i++){
                for(j=0; j<s->context_count[i]; j++){
                    for(k=0; k<32; k++){
                        for(m=0; m<2; m++){
                            s->rc_stat2[i][j][k][m]= strtol(p, &next, 0);
                            if(next==p){
                                av_log(avctx, AV_LOG_ERROR, "2Pass file invalid at %d %d %d %d [%s]\n", i,j,k,m,p);
                                return -1;
                            }
                            p=next;
                        }
                    }
                }
            }
            gob_count= strtol(p, &next, 0);
            if(next==p || gob_count <0){
                av_log(avctx, AV_LOG_ERROR, "2Pass file invalid\n");
                return -1;
            }
            p=next;
            while(*p=='\n' || *p==' ') p++;
            if(p[0]==0) break;
        }
        sort_stt(s, s->state_transition);

        find_best_state(best_state, s->state_transition);

        for(i=0; i<s->quant_table_count; i++){
            for(j=0; j<s->context_count[i]; j++){
                for(k=0; k<32; k++){
                    double p= 128;
                    if(s->rc_stat2[i][j][k][0]+s->rc_stat2[i][j][k][1]){
                        p=256.0*s->rc_stat2[i][j][k][1] / (s->rc_stat2[i][j][k][0]+s->rc_stat2[i][j][k][1]);
                    }
                    s->initial_states[i][j][k]= best_state[av_clip(round(p), 1, 255)][av_clip((s->rc_stat2[i][j][k][0]+s->rc_stat2[i][j][k][1])/gob_count, 0, 255)];
                }
            }
        }
    }

    if(s->version>1){
        s->num_h_slices=2;
        s->num_v_slices=2;
        write_extra_header(s);
    }

    if(init_slice_contexts(s) < 0)
        return -1;
    if(init_slice_state(s) < 0)
        return -1;

#define STATS_OUT_SIZE 1024*1024*6
    if(avctx->flags & CODEC_FLAG_PASS1){
        avctx->stats_out= av_mallocz(STATS_OUT_SIZE);
        for(i=0; i<s->quant_table_count; i++){
            for(j=0; j<s->slice_count; j++){
                FFV1Context *sf= s->slice_context[j];
                av_assert0(!sf->rc_stat2[i]);
                sf->rc_stat2[i]= av_mallocz(s->context_count[i]*sizeof(*sf->rc_stat2[i]));
                if(!sf->rc_stat2[i])
                    return AVERROR(ENOMEM);
            }
        }
    }

    return 0;
}
#endif /* CONFIG_FFV1_ENCODER */


static void clear_state(FFV1Context *f){
    int i, si, j;

    for(si=0; si<f->slice_count; si++){
        FFV1Context *fs= f->slice_context[si];
        for(i=0; i<f->plane_count; i++){
            PlaneContext *p= &fs->plane[i];

            p->interlace_bit_state[0]= 128;
            p->interlace_bit_state[1]= 128;

            if(fs->ac){
                if(f->initial_states[p->quant_table_index]){
                    memcpy(p->state, f->initial_states[p->quant_table_index], CONTEXT_SIZE*p->context_count);
                }else
                memset(p->state, 128, CONTEXT_SIZE*p->context_count);
            }else{
            for(j=0; j<p->context_count; j++){
                    p->vlc_state[j].drift= 0;
                    p->vlc_state[j].error_sum= 4; //FFMAX((RANGE + 32)/64, 2);
                    p->vlc_state[j].bias= 0;
                    p->vlc_state[j].count= 1;
            }
            }
        }
    }
}

#if CONFIG_FFV1_ENCODER
static int encode_slice(AVCodecContext *c, void *arg){
    FFV1Context *fs= *(void**)arg;
    FFV1Context *f= fs->avctx->priv_data;
    int width = fs->slice_width;
    int height= fs->slice_height;
    int x= fs->slice_x;
    int y= fs->slice_y;
    AVFrame * const p= &f->picture;

    if(f->colorspace==0){
        const int chroma_width = -((-width )>>f->chroma_h_shift);
        const int chroma_height= -((-height)>>f->chroma_v_shift);
        const int cx= x>>f->chroma_h_shift;
        const int cy= y>>f->chroma_v_shift;

        encode_plane(fs, p->data[0] + x + y*p->linesize[0], width, height, p->linesize[0], 0);

        encode_plane(fs, p->data[1] + cx+cy*p->linesize[1], chroma_width, chroma_height, p->linesize[1], 1);
        encode_plane(fs, p->data[2] + cx+cy*p->linesize[2], chroma_width, chroma_height, p->linesize[2], 1);
    }else{
        encode_rgb_frame(fs, (uint32_t*)(p->data[0]) + x + y*(p->linesize[0]/4), width, height, p->linesize[0]/4);
    }
    emms_c();

    return 0;
}

static int encode_frame(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
    FFV1Context *f = avctx->priv_data;
    RangeCoder * const c= &f->slice_context[0]->c;
    AVFrame *pict = data;
    AVFrame * const p= &f->picture;
    int used_count= 0;
    uint8_t keystate=128;
    uint8_t *buf_p;
    int i;

    ff_init_range_encoder(c, buf, buf_size);
    ff_build_rac_states(c, 0.05*(1LL<<32), 256-8);

    *p = *pict;
    p->pict_type= FF_I_TYPE;

    if(avctx->gop_size==0 || f->picture_number % avctx->gop_size == 0){
        put_rac(c, &keystate, 1);
        p->key_frame= 1;
        f->gob_count++;
        write_header(f);
        clear_state(f);
    }else{
        put_rac(c, &keystate, 0);
        p->key_frame= 0;
    }

    if(!f->ac){
        used_count += ff_rac_terminate(c);
//printf("pos=%d\n", used_count);
        init_put_bits(&f->slice_context[0]->pb, buf + used_count, buf_size - used_count);
    }else if (f->ac>1){
        int i;
        for(i=1; i<256; i++){
            c->one_state[i]= f->state_transition[i];
            c->zero_state[256-i]= 256-c->one_state[i];
        }
    }

    for(i=1; i<f->slice_count; i++){
        FFV1Context *fs= f->slice_context[i];
        uint8_t *start= buf + (buf_size-used_count)*i/f->slice_count;
        int len= buf_size/f->slice_count;

        if(fs->ac){
            ff_init_range_encoder(&fs->c, start, len);
        }else{
            init_put_bits(&fs->pb, start, len);
        }
    }
    avctx->execute(avctx, encode_slice, &f->slice_context[0], NULL, f->slice_count, sizeof(void*));

    buf_p=buf;
    for(i=0; i<f->slice_count; i++){
        FFV1Context *fs= f->slice_context[i];
        int bytes;

        if(fs->ac){
            uint8_t state=128;
            put_rac(&fs->c, &state, 0);
            bytes= ff_rac_terminate(&fs->c);
        }else{
            flush_put_bits(&fs->pb); //nicer padding FIXME
            bytes= used_count + (put_bits_count(&fs->pb)+7)/8;
            used_count= 0;
        }
        if(i>0){
            av_assert0(bytes < buf_size/f->slice_count);
            memmove(buf_p, fs->ac ? fs->c.bytestream_start : fs->pb.buf, bytes);
            av_assert0(bytes < (1<<24));
            AV_WB24(buf_p+bytes, bytes);
            bytes+=3;
        }
        buf_p += bytes;
    }

    if((avctx->flags&CODEC_FLAG_PASS1) && (f->picture_number&31)==0){
        int j, k, m;
        char *p= avctx->stats_out;
        char *end= p + STATS_OUT_SIZE;

        memset(f->rc_stat, 0, sizeof(f->rc_stat));
        for(i=0; i<f->quant_table_count; i++)
            memset(f->rc_stat2[i], 0, f->context_count[i]*sizeof(*f->rc_stat2[i]));

        for(j=0; j<f->slice_count; j++){
            FFV1Context *fs= f->slice_context[j];
            for(i=0; i<256; i++){
                f->rc_stat[i][0] += fs->rc_stat[i][0];
                f->rc_stat[i][1] += fs->rc_stat[i][1];
            }
            for(i=0; i<f->quant_table_count; i++){
                for(k=0; k<f->context_count[i]; k++){
                    for(m=0; m<32; m++){
                        f->rc_stat2[i][k][m][0] += fs->rc_stat2[i][k][m][0];
                        f->rc_stat2[i][k][m][1] += fs->rc_stat2[i][k][m][1];
                    }
                }
            }
        }

        for(j=0; j<256; j++){
            snprintf(p, end-p, "%"PRIu64" %"PRIu64" ", f->rc_stat[j][0], f->rc_stat[j][1]);
            p+= strlen(p);
        }
        snprintf(p, end-p, "\n");

        for(i=0; i<f->quant_table_count; i++){
            for(j=0; j<f->context_count[i]; j++){
                for(m=0; m<32; m++){
                    snprintf(p, end-p, "%"PRIu64" %"PRIu64" ", f->rc_stat2[i][j][m][0], f->rc_stat2[i][j][m][1]);
                    p+= strlen(p);
                }
            }
        }
        snprintf(p, end-p, "%d\n", f->gob_count);
    } else if(avctx->flags&CODEC_FLAG_PASS1)
        avctx->stats_out[0] = '\0';

    f->picture_number++;
    return buf_p-buf;
}
#endif /* CONFIG_FFV1_ENCODER */

static av_cold int common_end(AVCodecContext *avctx){
    FFV1Context *s = avctx->priv_data;
    int i, j;

    if (avctx->codec->decode && s->picture.data[0])
        avctx->release_buffer(avctx, &s->picture);

    for(j=0; j<s->slice_count; j++){
        FFV1Context *fs= s->slice_context[j];
        for(i=0; i<s->plane_count; i++){
            PlaneContext *p= &fs->plane[i];

            av_freep(&p->state);
            av_freep(&p->vlc_state);
        }
        av_freep(&fs->sample_buffer);
    }

    av_freep(&avctx->stats_out);
    for(j=0; j<s->quant_table_count; j++){
        av_freep(&s->initial_states[j]);
        for(i=0; i<s->slice_count; i++){
            FFV1Context *sf= s->slice_context[i];
            av_freep(&sf->rc_stat2[j]);
        }
        av_freep(&s->rc_stat2[j]);
    }

    for(i=0; i<s->slice_count; i++){
        av_freep(&s->slice_context[i]);
    }

    return 0;
}

static av_always_inline void decode_line(FFV1Context *s, int w, int_fast16_t *sample[2], int plane_index, int bits){
    PlaneContext * const p= &s->plane[plane_index];
    RangeCoder * const c= &s->c;
    int x;
    int run_count=0;
    int run_mode=0;
    int run_index= s->run_index;

    for(x=0; x<w; x++){
        int diff, context, sign;

        context= get_context(p, sample[1] + x, sample[0] + x, sample[1] + x);
        if(context < 0){
            context= -context;
            sign=1;
        }else
            sign=0;

        av_assert2(context < p->context_count);

        if(s->ac){
            diff= get_symbol_inline(c, p->state[context], 1);
        }else{
            if(context == 0 && run_mode==0) run_mode=1;

            if(run_mode){
                if(run_count==0 && run_mode==1){
                    if(get_bits1(&s->gb)){
                        run_count = 1<<ff_log2_run[run_index];
                        if(x + run_count <= w) run_index++;
                    }else{
                        if(ff_log2_run[run_index]) run_count = get_bits(&s->gb, ff_log2_run[run_index]);
                        else run_count=0;
                        if(run_index) run_index--;
                        run_mode=2;
                    }
                }
                run_count--;
                if(run_count < 0){
                    run_mode=0;
                    run_count=0;
                    diff= get_vlc_symbol(&s->gb, &p->vlc_state[context], bits);
                    if(diff>=0) diff++;
                }else
                    diff=0;
            }else
                diff= get_vlc_symbol(&s->gb, &p->vlc_state[context], bits);

//            printf("count:%d index:%d, mode:%d, x:%d y:%d pos:%d\n", run_count, run_index, run_mode, x, y, get_bits_count(&s->gb));
        }

        if(sign) diff= -diff;

        sample[1][x]= (predict(sample[1] + x, sample[0] + x) + diff) & ((1<<bits)-1);
    }
    s->run_index= run_index;
}

static void decode_plane(FFV1Context *s, uint8_t *src, int w, int h, int stride, int plane_index){
    int x, y;
    int_fast16_t *sample[2];
    sample[0]=s->sample_buffer    +3;
    sample[1]=s->sample_buffer+w+6+3;

    s->run_index=0;

    memset(s->sample_buffer, 0, 2*(w+6)*sizeof(*s->sample_buffer));

    for(y=0; y<h; y++){
        int_fast16_t *temp= sample[0]; //FIXME try a normal buffer

        sample[0]= sample[1];
        sample[1]= temp;

        sample[1][-1]= sample[0][0  ];
        sample[0][ w]= sample[0][w-1];

//{START_TIMER
        if(s->avctx->bits_per_raw_sample <= 8){
            decode_line(s, w, sample, plane_index, 8);
            for(x=0; x<w; x++){
                src[x + stride*y]= sample[1][x];
            }
        }else{
            decode_line(s, w, sample, plane_index, s->avctx->bits_per_raw_sample);
            for(x=0; x<w; x++){
                ((uint16_t*)(src + stride*y))[x]= sample[1][x] << (16 - s->avctx->bits_per_raw_sample);
            }
        }
//STOP_TIMER("decode-line")}
    }
}

static void decode_rgb_frame(FFV1Context *s, uint32_t *src, int w, int h, int stride){
    int x, y, p;
    int_fast16_t *sample[3][2];
    for(x=0; x<3; x++){
        sample[x][0] = s->sample_buffer +  x*2   *(w+6) + 3;
        sample[x][1] = s->sample_buffer + (x*2+1)*(w+6) + 3;
    }

    s->run_index=0;

    memset(s->sample_buffer, 0, 6*(w+6)*sizeof(*s->sample_buffer));

    for(y=0; y<h; y++){
        for(p=0; p<3; p++){
            int_fast16_t *temp= sample[p][0]; //FIXME try a normal buffer

            sample[p][0]= sample[p][1];
            sample[p][1]= temp;

            sample[p][1][-1]= sample[p][0][0  ];
            sample[p][0][ w]= sample[p][0][w-1];
            decode_line(s, w, sample[p], FFMIN(p, 1), 9);
        }
        for(x=0; x<w; x++){
            int g= sample[0][1][x];
            int b= sample[1][1][x];
            int r= sample[2][1][x];

//            assert(g>=0 && b>=0 && r>=0);
//            assert(g<256 && b<512 && r<512);

            b -= 0x100;
            r -= 0x100;
            g -= (b + r)>>2;
            b += g;
            r += g;

            src[x + stride*y]= b + (g<<8) + (r<<16) + (0xFF<<24);
        }
    }
}

static int decode_slice(AVCodecContext *c, void *arg){
    FFV1Context *fs= *(void**)arg;
    FFV1Context *f= fs->avctx->priv_data;
    int width = fs->slice_width;
    int height= fs->slice_height;
    int x= fs->slice_x;
    int y= fs->slice_y;
    AVFrame * const p= &f->picture;

    av_assert1(width && height);
    if(f->colorspace==0){
        const int chroma_width = -((-width )>>f->chroma_h_shift);
        const int chroma_height= -((-height)>>f->chroma_v_shift);
        const int cx= x>>f->chroma_h_shift;
        const int cy= y>>f->chroma_v_shift;
        decode_plane(fs, p->data[0] + x + y*p->linesize[0], width, height, p->linesize[0], 0);

        decode_plane(fs, p->data[1] + cx+cy*p->linesize[1], chroma_width, chroma_height, p->linesize[1], 1);
        decode_plane(fs, p->data[2] + cx+cy*p->linesize[1], chroma_width, chroma_height, p->linesize[2], 1);
    }else{
        decode_rgb_frame(fs, (uint32_t*)p->data[0] + x + y*(p->linesize[0]/4), width, height, p->linesize[0]/4);
    }

    emms_c();

    return 0;
}

static int read_quant_table(RangeCoder *c, int16_t *quant_table, int scale){
    int v;
    int i=0;
    uint8_t state[CONTEXT_SIZE];

    memset(state, 128, sizeof(state));

    for(v=0; i<128 ; v++){
        int len= get_symbol(c, state, 0) + 1;

        if(len + i > 128) return -1;

        while(len--){
            quant_table[i] = scale*v;
            i++;
//printf("%2d ",v);
//if(i%16==0) printf("\n");
        }
    }

    for(i=1; i<128; i++){
        quant_table[256-i]= -quant_table[i];
    }
    quant_table[128]= -quant_table[127];

    return 2*v - 1;
}

static int read_quant_tables(RangeCoder *c, int16_t quant_table[MAX_CONTEXT_INPUTS][256]){
    int i;
    int context_count=1;

    for(i=0; i<5; i++){
        context_count*= read_quant_table(c, quant_table[i], context_count);
        if(context_count > 32768U){
            return -1;
        }
    }
    return (context_count+1)/2;
}

static int read_extra_header(FFV1Context *f){
    RangeCoder * const c= &f->c;
    uint8_t state[CONTEXT_SIZE];
    int i, j, k;
    uint8_t state2[32][CONTEXT_SIZE];

    memset(state2, 128, sizeof(state2));
    memset(state, 128, sizeof(state));

    ff_init_range_decoder(c, f->avctx->extradata, f->avctx->extradata_size);
    ff_build_rac_states(c, 0.05*(1LL<<32), 256-8);

    f->version= get_symbol(c, state, 0);
    f->ac= f->avctx->coder_type= get_symbol(c, state, 0);
    if(f->ac>1){
        for(i=1; i<256; i++){
            f->state_transition[i]= get_symbol(c, state, 1) + c->one_state[i];
        }
    }
    f->colorspace= get_symbol(c, state, 0); //YUV cs type
    f->avctx->bits_per_raw_sample= get_symbol(c, state, 0);
    get_rac(c, state); //no chroma = false
    f->chroma_h_shift= get_symbol(c, state, 0);
    f->chroma_v_shift= get_symbol(c, state, 0);
    get_rac(c, state); //transparency plane
    f->plane_count= 2;
    f->num_h_slices= 1 + get_symbol(c, state, 0);
    f->num_v_slices= 1 + get_symbol(c, state, 0);
    if(f->num_h_slices > (unsigned)f->width || f->num_v_slices > (unsigned)f->height){
        av_log(f->avctx, AV_LOG_ERROR, "too many slices\n");
        return -1;
    }

    f->quant_table_count= get_symbol(c, state, 0);
    if(f->quant_table_count > (unsigned)MAX_QUANT_TABLES)
        return -1;
    for(i=0; i<f->quant_table_count; i++){
        if((f->context_count[i]= read_quant_tables(c, f->quant_tables[i])) < 0){
            av_log(f->avctx, AV_LOG_ERROR, "read_quant_table error\n");
            return -1;
        }
    }

    if(allocate_initial_states(f) < 0)
        return AVERROR(ENOMEM);

    for(i=0; i<f->quant_table_count; i++){
        if(get_rac(c, state)){
            for(j=0; j<f->context_count[i]; j++){
                for(k=0; k<CONTEXT_SIZE; k++){
                    int pred= j ? f->initial_states[i][j-1][k] : 128;
                    f->initial_states[i][j][k]= (pred+get_symbol(c, state2[k], 1))&0xFF;
                }
            }
        }
    }

    return 0;
}

static int read_header(FFV1Context *f){
    uint8_t state[CONTEXT_SIZE];
    int i, j, context_count;
    RangeCoder * const c= &f->slice_context[0]->c;

    memset(state, 128, sizeof(state));

    if(f->version < 2){
        f->version= get_symbol(c, state, 0);
        f->ac= f->avctx->coder_type= get_symbol(c, state, 0);
        if(f->ac>1){
            for(i=1; i<256; i++){
                f->state_transition[i]= get_symbol(c, state, 1) + c->one_state[i];
            }
        }
        f->colorspace= get_symbol(c, state, 0); //YUV cs type
        if(f->version>0)
            f->avctx->bits_per_raw_sample= get_symbol(c, state, 0);
        get_rac(c, state); //no chroma = false
        f->chroma_h_shift= get_symbol(c, state, 0);
        f->chroma_v_shift= get_symbol(c, state, 0);
        get_rac(c, state); //transparency plane
        f->plane_count= 2;
    }

    if(f->colorspace==0){
        if(f->avctx->bits_per_raw_sample<=8){
            switch(16*f->chroma_h_shift + f->chroma_v_shift){
            case 0x00: f->avctx->pix_fmt= PIX_FMT_YUV444P; break;
            case 0x10: f->avctx->pix_fmt= PIX_FMT_YUV422P; break;
            case 0x11: f->avctx->pix_fmt= PIX_FMT_YUV420P; break;
            case 0x20: f->avctx->pix_fmt= PIX_FMT_YUV411P; break;
            case 0x22: f->avctx->pix_fmt= PIX_FMT_YUV410P; break;
            default:
                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
                return -1;
            }
        }else{
            switch(16*f->chroma_h_shift + f->chroma_v_shift){
            case 0x00: f->avctx->pix_fmt= PIX_FMT_YUV444P16; break;
            case 0x10: f->avctx->pix_fmt= PIX_FMT_YUV422P16; break;
            case 0x11: f->avctx->pix_fmt= PIX_FMT_YUV420P16; break;
            default:
                av_log(f->avctx, AV_LOG_ERROR, "format not supported\n");
                return -1;
            }
        }
    }else if(f->colorspace==1){
        if(f->chroma_h_shift || f->chroma_v_shift){
            av_log(f->avctx, AV_LOG_ERROR, "chroma subsampling not supported in this colorspace\n");
            return -1;
        }
        f->avctx->pix_fmt= PIX_FMT_RGB32;
    }else{
        av_log(f->avctx, AV_LOG_ERROR, "colorspace not supported\n");
        return -1;
    }

//printf("%d %d %d\n", f->chroma_h_shift, f->chroma_v_shift,f->avctx->pix_fmt);
    if(f->version < 2){
        context_count= read_quant_tables(c, f->quant_table);
        if(context_count < 0){
                av_log(f->avctx, AV_LOG_ERROR, "read_quant_table error\n");
                return -1;
        }
    }else{
        f->slice_count= get_symbol(c, state, 0);
        if(f->slice_count > (unsigned)MAX_SLICES)
            return -1;
    }

    for(j=0; j<f->slice_count; j++){
        FFV1Context *fs= f->slice_context[j];
        fs->ac= f->ac;

        if(f->version >= 2){
            fs->slice_x     = get_symbol(c, state, 0)   *f->width ;
            fs->slice_y     = get_symbol(c, state, 0)   *f->height;
            fs->slice_width =(get_symbol(c, state, 0)+1)*f->width  + fs->slice_x;
            fs->slice_height=(get_symbol(c, state, 0)+1)*f->height + fs->slice_y;

            fs->slice_x /= f->num_h_slices;
            fs->slice_y /= f->num_v_slices;
            fs->slice_width  = fs->slice_width /f->num_h_slices - fs->slice_x;
            fs->slice_height = fs->slice_height/f->num_v_slices - fs->slice_y;
            if((unsigned)fs->slice_width > f->width || (unsigned)fs->slice_height > f->height)
                return -1;
            if(    (unsigned)fs->slice_x + (uint64_t)fs->slice_width  > f->width
                || (unsigned)fs->slice_y + (uint64_t)fs->slice_height > f->height)
                return -1;
        }

        for(i=0; i<f->plane_count; i++){
            PlaneContext * const p= &fs->plane[i];

            if(f->version >= 2){
                int idx=get_symbol(c, state, 0);
                if(idx > (unsigned)f->quant_table_count){
                    av_log(f->avctx, AV_LOG_ERROR, "quant_table_index out of range\n");
                    return -1;
                }
                p->quant_table_index= idx;
                memcpy(p->quant_table, f->quant_tables[idx], sizeof(p->quant_table));
                context_count= f->context_count[idx];
            }else{
                memcpy(p->quant_table, f->quant_table, sizeof(p->quant_table));
            }

            if(p->context_count < context_count){
                av_freep(&p->state);
                av_freep(&p->vlc_state);
            }
            p->context_count= context_count;
        }
    }

    return 0;
}

static av_cold int decode_init(AVCodecContext *avctx)
{
    FFV1Context *f = avctx->priv_data;

    common_init(avctx);

    if(avctx->extradata && read_extra_header(f) < 0)
        return -1;

    if(init_slice_contexts(f) < 0)
        return -1;

    return 0;
}

static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt){
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    FFV1Context *f = avctx->priv_data;
    RangeCoder * const c= &f->slice_context[0]->c;
    AVFrame * const p= &f->picture;
    int bytes_read, i;
    uint8_t keystate= 128;
    const uint8_t *buf_p;

    AVFrame *picture = data;

    /* release previously stored data */
    if (p->data[0])
        avctx->release_buffer(avctx, p);

    ff_init_range_decoder(c, buf, buf_size);
    ff_build_rac_states(c, 0.05*(1LL<<32), 256-8);


    p->pict_type= FF_I_TYPE; //FIXME I vs. P
    if(get_rac(c, &keystate)){
        p->key_frame= 1;
        if(read_header(f) < 0)
            return -1;
        if(init_slice_state(f) < 0)
            return -1;

        clear_state(f);
    }else{
        p->key_frame= 0;
    }
    if(f->ac>1){
        int i;
        for(i=1; i<256; i++){
            c->one_state[i]= f->state_transition[i];
            c->zero_state[256-i]= 256-c->one_state[i];
        }
    }

    p->reference= 0;
    if(avctx->get_buffer(avctx, p) < 0){
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return -1;
    }

    if(avctx->debug&FF_DEBUG_PICT_INFO)
        av_log(avctx, AV_LOG_ERROR, "keyframe:%d coder:%d\n", p->key_frame, f->ac);

    if(!f->ac){
        bytes_read = c->bytestream - c->bytestream_start - 1;
        if(bytes_read ==0) av_log(avctx, AV_LOG_ERROR, "error at end of AC stream\n"); //FIXME
//printf("pos=%d\n", bytes_read);
        init_get_bits(&f->slice_context[0]->gb, buf + bytes_read, buf_size - bytes_read);
    } else {
        bytes_read = 0; /* avoid warning */
    }

    buf_p= buf + buf_size;
    for(i=f->slice_count-1; i>0; i--){
        FFV1Context *fs= f->slice_context[i];
        int v= AV_RB24(buf_p-3)+3;
        if(buf_p - buf <= v){
            av_log(avctx, AV_LOG_ERROR, "Slice pointer chain broken\n");
            return -1;
        }
        buf_p -= v;
        if(fs->ac){
            ff_init_range_decoder(&fs->c, buf_p, v);
        }else{
            init_get_bits(&fs->gb, buf_p, v);
        }
    }

    avctx->execute(avctx, decode_slice, &f->slice_context[0], NULL, f->slice_count, sizeof(void*));
    f->picture_number++;

    *picture= *p;
    *data_size = sizeof(AVFrame);

    return buf_size;
}

AVCodec ff_ffv1_decoder = {
    "ffv1",
    AVMEDIA_TYPE_VIDEO,
    CODEC_ID_FFV1,
    sizeof(FFV1Context),
    decode_init,
    NULL,
    common_end,
    decode_frame,
    CODEC_CAP_DR1 /*| CODEC_CAP_DRAW_HORIZ_BAND*/,
    NULL,
    .long_name= NULL_IF_CONFIG_SMALL("FFmpeg video codec #1"),
};

#if CONFIG_FFV1_ENCODER
AVCodec ff_ffv1_encoder = {
    "ffv1",
    AVMEDIA_TYPE_VIDEO,
    CODEC_ID_FFV1,
    sizeof(FFV1Context),
    encode_init,
    encode_frame,
    common_end,
    .pix_fmts= (const enum PixelFormat[]){PIX_FMT_YUV420P, PIX_FMT_YUV444P, PIX_FMT_YUV422P, PIX_FMT_YUV411P, PIX_FMT_YUV410P, PIX_FMT_RGB32, PIX_FMT_YUV420P16, PIX_FMT_YUV422P16, PIX_FMT_YUV444P16, PIX_FMT_NONE},
    .long_name= NULL_IF_CONFIG_SMALL("FFmpeg video codec #1"),
};
#endif