mjpegdec.c

从FFMPEG转换而来的H264解码程序,VC下编译..

                        int component, int dc_index, int ac_index, int16_t *quant_matrix,
                        int ss, int se, int Ah, int Al, int *EOBRUN)
{
    int code, i, j, level, val, run;

    /* DC coef */
    if(!ss){
        val = mjpeg_decode_dc(s, dc_index);
        if (val == 0xffff) {
            av_log(s->avctx, AV_LOG_ERROR, "error dc\n");
            return -1;
        }
        val = (val * quant_matrix[0] << Al) + s->last_dc[component];
    }else
        val = 0;
    s->last_dc[component] = val;
    block[0] = val;
    if(!se) return 0;
    /* AC coefs */
    if(*EOBRUN){
        (*EOBRUN)--;
        return 0;
    }
    {OPEN_READER(re, &s->gb)
    for(i=ss;;i++) {
        UPDATE_CACHE(re, &s->gb);
        GET_VLC(code, re, &s->gb, s->vlcs[1][ac_index].table, 9, 2)
        /* Progressive JPEG use AC coeffs from zero and this decoder sets offset 16 by default */
        code -= 16;
        if(code & 0xF) {
            i += ((unsigned) code) >> 4;
            code &= 0xf;
            if(code > MIN_CACHE_BITS - 16){
                UPDATE_CACHE(re, &s->gb)
            }
            {
                int cache=GET_CACHE(re,&s->gb);
                int sign=(~cache)>>31;
                level = (NEG_USR32(sign ^ cache,code) ^ sign) - sign;
            }

            LAST_SKIP_BITS(re, &s->gb, code)

            if (i >= se) {
                if(i == se){
                    j = s->scantable.permutated[se];
                    block[j] = level * quant_matrix[j] << Al;
                    break;
                }
                av_log(s->avctx, AV_LOG_ERROR, "error count: %d\n", i);
                return -1;
            }
            j = s->scantable.permutated[i];
            block[j] = level * quant_matrix[j] << Al;
        }else{
            run = ((unsigned) code) >> 4;
            if(run == 0xF){// ZRL - skip 15 coefficients
                i += 15;
            }else{
                val = run;
                run = (1 << run);
                UPDATE_CACHE(re, &s->gb);
                run += (GET_CACHE(re, &s->gb) >> (32 - val)) & (run - 1);
                if(val)
                    LAST_SKIP_BITS(re, &s->gb, val);
                *EOBRUN = run - 1;
                break;
            }
        }
    }
    CLOSE_READER(re, &s->gb)}

    return 0;
}

static int ljpeg_decode_rgb_scan(MJpegDecodeContext *s, int predictor, int point_transform){
    int i, mb_x, mb_y;
    //uint16_t buffer[32768][4];
    int left[3], top[3], topleft[3];
    const int linesize= s->linesize[0];
    const int mask= (1<<s->bits)-1;

    if((unsigned)s->mb_width > 32768) //dynamic alloc
        return -1;

    for(i=0; i<3; i++){
        s->RGBbuffer[0][i]= 1 << (s->bits + point_transform - 1);
    }
    for(mb_y = 0; mb_y < s->mb_height; mb_y++) {
        const int modified_predictor= mb_y ? predictor : 1;
        uint8_t *ptr = s->picture.data[0] + (linesize * mb_y);

        if (s->interlaced && s->bottom_field)
            ptr += linesize >> 1;

        for(i=0; i<3; i++){
            top[i]= left[i]= topleft[i]= s->RGBbuffer[0][i];
        }
        for(mb_x = 0; mb_x < s->mb_width; mb_x++) {
            if (s->restart_interval && !s->restart_count)
                s->restart_count = s->restart_interval;

            for(i=0;i<3;i++) {
                int pred;

                topleft[i]= top[i];
                top[i]= s->RGBbuffer[mb_x][i];

                PREDICT(pred, topleft[i], top[i], left[i], modified_predictor);

                left[i]=
                s->RGBbuffer[mb_x][i]= mask & (pred + (mjpeg_decode_dc(s, s->dc_index[i]) << point_transform));
            }

            if (s->restart_interval && !--s->restart_count) {
                align_get_bits(&s->gb);
                skip_bits(&s->gb, 16); /* skip RSTn */
            }
        }

        if(s->rct){
            for(mb_x = 0; mb_x < s->mb_width; mb_x++) {
                ptr[4*mb_x+1] = s->RGBbuffer[mb_x][0] - ((s->RGBbuffer[mb_x][1] + s->RGBbuffer[mb_x][2] - 0x200)>>2);
                ptr[4*mb_x+0] = s->RGBbuffer[mb_x][1] + ptr[4*mb_x+1];
                ptr[4*mb_x+2] = s->RGBbuffer[mb_x][2] + ptr[4*mb_x+1];
            }
        }else if(s->pegasus_rct){
            for(mb_x = 0; mb_x < s->mb_width; mb_x++) {
                ptr[4*mb_x+1] = s->RGBbuffer[mb_x][0] - ((s->RGBbuffer[mb_x][1] + s->RGBbuffer[mb_x][2])>>2);
                ptr[4*mb_x+0] = s->RGBbuffer[mb_x][1] + ptr[4*mb_x+1];
                ptr[4*mb_x+2] = s->RGBbuffer[mb_x][2] + ptr[4*mb_x+1];
            }
        }else{
            for(mb_x = 0; mb_x < s->mb_width; mb_x++) {
                ptr[4*mb_x+0] = s->RGBbuffer[mb_x][0];
                ptr[4*mb_x+1] = s->RGBbuffer[mb_x][1];
                ptr[4*mb_x+2] = s->RGBbuffer[mb_x][2];
            }
        }
    }
    return 0;
}

static int ljpeg_decode_yuv_scan(MJpegDecodeContext *s, int predictor, int point_transform){
    int i, mb_x, mb_y;
    const int nb_components=3;

    for(mb_y = 0; mb_y < s->mb_height; mb_y++) {
        for(mb_x = 0; mb_x < s->mb_width; mb_x++) {
            if (s->restart_interval && !s->restart_count)
                s->restart_count = s->restart_interval;

            if(mb_x==0 || mb_y==0 || s->interlaced){
                for(i=0;i<nb_components;i++) {
                    uint8_t *ptr;
                    int n, h, v, x, y, c, j, linesize;
                    n = s->nb_blocks[i];
                    c = s->comp_index[i];
                    h = s->h_scount[i];
                    v = s->v_scount[i];
                    x = 0;
                    y = 0;
                    linesize= s->linesize[c];

                    for(j=0; j<n; j++) {
                        int pred;

                        ptr = s->picture.data[c] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap
                        if(y==0 && mb_y==0){
                            if(x==0 && mb_x==0){
                                pred= 128 << point_transform;
                            }else{
                                pred= ptr[-1];
                            }
                        }else{
                            if(x==0 && mb_x==0){
                                pred= ptr[-linesize];
                            }else{
                                PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);
                            }
                        }

                        if (s->interlaced && s->bottom_field)
                            ptr += linesize >> 1;
                        *ptr= pred + (mjpeg_decode_dc(s, s->dc_index[i]) << point_transform);

                        if (++x == h) {
                            x = 0;
                            y++;
                        }
                    }
                }
            }else{
                for(i=0;i<nb_components;i++) {
                    uint8_t *ptr;
                    int n, h, v, x, y, c, j, linesize;
                    n = s->nb_blocks[i];
                    c = s->comp_index[i];
                    h = s->h_scount[i];
                    v = s->v_scount[i];
                    x = 0;
                    y = 0;
                    linesize= s->linesize[c];

                    for(j=0; j<n; j++) {
                        int pred;

                        ptr = s->picture.data[c] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap
                        PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);
                        *ptr= pred + (mjpeg_decode_dc(s, s->dc_index[i]) << point_transform);
                        if (++x == h) {
                            x = 0;
                            y++;
                        }
                    }
                }
            }
            if (s->restart_interval && !--s->restart_count) {
                align_get_bits(&s->gb);
                skip_bits(&s->gb, 16); /* skip RSTn */
            }
        }
    }
    return 0;
}

static int mjpeg_decode_scan(MJpegDecodeContext *s, int nb_components, int ss, int se, int Ah, int Al){
    int i, mb_x, mb_y;
    int EOBRUN = 0;

    if(Ah) return 0; /* TODO decode refinement planes too */
    for(mb_y = 0; mb_y < s->mb_height; mb_y++) {
        for(mb_x = 0; mb_x < s->mb_width; mb_x++) {
            if (s->restart_interval && !s->restart_count)
                s->restart_count = s->restart_interval;

            for(i=0;i<nb_components;i++) {
                uint8_t *ptr;
                int n, h, v, x, y, c, j;
                n = s->nb_blocks[i];
                c = s->comp_index[i];
                h = s->h_scount[i];
                v = s->v_scount[i];
                x = 0;
                y = 0;
                for(j=0;j<n;j++) {
                    memset(s->block, 0, sizeof(s->block));
                    if (!s->progressive && decode_block(s, s->block, i,
                                     s->dc_index[i], s->ac_index[i],
                                     s->quant_matrixes[ s->quant_index[c] ]) < 0) {
                        av_log(s->avctx, AV_LOG_ERROR, "error y=%d x=%d\n", mb_y, mb_x);
                        return -1;
                    }
                    if (s->progressive && decode_block_progressive(s, s->block, i,
                                     s->dc_index[i], s->ac_index[i],
                                     s->quant_matrixes[ s->quant_index[c] ], ss, se, Ah, Al, &EOBRUN) < 0) {
                        av_log(s->avctx, AV_LOG_ERROR, "error y=%d x=%d\n", mb_y, mb_x);
                        return -1;
                    }
//                    av_log(s->avctx, AV_LOG_DEBUG, "mb: %d %d processed\n", mb_y, mb_x);
                    ptr = s->picture.data[c] +
                        (((s->linesize[c] * (v * mb_y + y) * 8) +
                        (h * mb_x + x) * 8) >> s->avctx->lowres);
                    if (s->interlaced && s->bottom_field)
                        ptr += s->linesize[c] >> 1;
//av_log(NULL, AV_LOG_DEBUG, "%d %d %d %d %d %d %d %d \n", mb_x, mb_y, x, y, c, s->bottom_field, (v * mb_y + y) * 8, (h * mb_x + x) * 8);
                    if(!s->progressive)
                        s->dsp.idct_put(ptr, s->linesize[c], s->block);
                    else
                        s->dsp.idct_add(ptr, s->linesize[c], s->block);
                    if (++x == h) {
                        x = 0;
                        y++;
                    }
                }
            }
            /* (< 1350) buggy workaround for Spectralfan.mov, should be fixed */
            if (s->restart_interval && (s->restart_interval < 1350) &&
                !--s->restart_count) {
                align_get_bits(&s->gb);
                skip_bits(&s->gb, 16); /* skip RSTn */
                for (i=0; i<nb_components; i++) /* reset dc */
                    s->last_dc[i] = 1024;
            }
        }
    }
    return 0;
}

int ff_mjpeg_decode_sos(MJpegDecodeContext *s)
{
    int len, nb_components, i, h, v, predictor, point_transform;
    int vmax, hmax, index, id;
    const int block_size= s->lossless ? 1 : 8;
    int ilv, prev_shift;

    /* XXX: verify len field validity */
    len = get_bits(&s->gb, 16);
    nb_components = get_bits(&s->gb, 8);
    if (len != 6+2*nb_components)
    {
        av_log(s->avctx, AV_LOG_ERROR, "decode_sos: invalid len (%d)\n", len);
        return -1;
    }
    vmax = 0;
    hmax = 0;
    for(i=0;i<nb_components;i++) {
        id = get_bits(&s->gb, 8) - 1;
        av_log(s->avctx, AV_LOG_DEBUG, "component: %d\n", id);
        /* find component index */
        for(index=0;index<s->nb_components;index++)
            if (id == s->component_id[index])
                break;
        if (index == s->nb_components)
        {
            av_log(s->avctx, AV_LOG_ERROR, "decode_sos: index(%d) out of components\n", index);
            return -1;
        }

        s->comp_index[i] = index;

        s->nb_blocks[i] = s->h_count[index] * s->v_count[index];
        s->h_scount[i] = s->h_count[index];
        s->v_scount[i] = s->v_count[index];

        s->dc_index[i] = get_bits(&s->gb, 4);
        s->ac_index[i] = get_bits(&s->gb, 4);

        if (s->dc_index[i] <  0 || s->ac_index[i] < 0 ||
            s->dc_index[i] >= 4 || s->ac_index[i] >= 4)
            goto out_of_range;
    }

    predictor= get_bits(&s->gb, 8); /* JPEG Ss / lossless JPEG predictor /JPEG-LS NEAR */
    ilv= get_bits(&s->gb, 8);    /* JPEG Se / JPEG-LS ILV */
    prev_shift = get_bits(&s->gb, 4); /* Ah */
    point_transform= get_bits(&s->gb, 4); /* Al */

    for(i=0;i<nb_components;i++)
        s->last_dc[i] = 1024;

    if (nb_components > 1) {
        /* interleaved stream */
        s->mb_width  = (s->width  + s->h_max * block_size - 1) / (s->h_max * block_size);
        s->mb_height = (s->height + s->v_max * block_size - 1) / (s->v_max * block_size);
    } else if(!s->ls) { /* skip this for JPEG-LS */
        h = s->h_max / s->h_scount[0];
        v = s->v_max / s->v_scount[0];
        s->mb_width  = (s->width  + h * block_size - 1) / (h * block_size);
        s->mb_height = (s->height + v * block_size - 1) / (v * block_size);
        s->nb_blocks[0] = 1;
        s->h_scount[0] = 1;
        s->v_scount[0] = 1;
    }

    if(s->avctx->debug & FF_DEBUG_PICT_INFO)
        av_log(s->avctx, AV_LOG_DEBUG, "%s %s p:%d >>:%d ilv:%d bits:%d %s\n", s->lossless ? "lossless" : "sequencial DCT", s->rgb ? "RGB" : "",
               predictor, point_transform, ilv, s->bits,
               s->pegasus_rct ? "PRCT" : (s->rct ? "RCT" : ""));


    /* mjpeg-b can have padding bytes between sos and image data, skip them */
    for (i = s->mjpb_skiptosod; i > 0; i--)
        skip_bits(&s->gb, 8);

    if(s->lossless){
        if(s->ls){
            ff_jpegls_decode_picture(s, predictor, point_transform, ilv);
        }else{
            if(s->rgb){
                if(ljpeg_decode_rgb_scan(s, predictor, point_transform) < 0)
                    return -1;
            }else{
                if(ljpeg_decode_yuv_scan(s, predictor, point_transform) < 0)
                    return -1;
            }
        }
    }else{
        if(mjpeg_decode_scan(s, nb_components, predictor, ilv, prev_shift, point_transform) < 0)
            return -1;
    }
    emms_c();
    return 0;
 out_of_range:
    av_log(s->avctx, AV_LOG_ERROR, "decode_sos: ac/dc index out of range\n");
    return -1;
}

static int mjpeg_decode_dri(MJpegDecodeContext *s)
{
    if (get_bits(&s->gb, 16) != 4)
        return -1;
    s->restart_interval = get_bits(&s->gb, 16);
    s->restart_count = 0;
    av_log(s->avctx, AV_LOG_DEBUG, "restart interval: %d\n", s->restart_interval);

    return 0;
}

static int mjpeg_decode_app(MJpegDecodeContext *s)
{
    int len, id, i;

    len = get_bits(&s->gb, 16);
    if (len < 5)
        return -1;
    if(8*len + get_bits_count(&s->gb) > s->gb.size_in_bits)
        return -1;

    id = (get_bits(&s->gb, 16) << 16) | get_bits(&s->gb, 16);
    id = be2me_32(id);
    len -= 6;

    if(s->avctx->debug & FF_DEBUG_STARTCODE){
        av_log(s->avctx, AV_LOG_DEBUG, "APPx %8X\n", id);
    }

    /* buggy AVID, it puts EOI only at every 10th frame */
    /* also this fourcc is used by non-avid files too, it holds some
       informations, but it's always present in AVID creates files */
    if (id == ff_get_fourcc("AVI1"))
    {
        s->buggy_avid = 1;

        i = get_bits(&s->gb, 8);