mjpeg.c

tcpmp播放器的flv插件

    const int mask= (1<<s->bits)-1;
    
    if((unsigned)s->mb_width > 32768) //dynamic alloc
        return -1;
    
    for(i=0; i<3; i++){
        buffer[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]= buffer[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]= buffer[mb_x][i];

                PREDICT(pred, topleft[i], top[i], left[i], modified_predictor);
                
                left[i]= 
                buffer[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] = buffer[mb_x][0] - ((buffer[mb_x][1] + buffer[mb_x][2] - 0x200)>>2);
                ptr[4*mb_x+0] = buffer[mb_x][1] + ptr[4*mb_x+1];
                ptr[4*mb_x+2] = buffer[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] = buffer[mb_x][0] - ((buffer[mb_x][1] + buffer[mb_x][2])>>2);
                ptr[4*mb_x+0] = buffer[mb_x][1] + ptr[4*mb_x+1];
                ptr[4*mb_x+2] = buffer[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] = buffer[mb_x][0];
                ptr[4*mb_x+1] = buffer[mb_x][1];
                ptr[4*mb_x+2] = buffer[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 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;

            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 (decode_block(s, s->block, i, 
                                     s->dc_index[i], s->ac_index[i], 
                                     s->quant_index[c]) < 0) {
                        dprintf("error y=%d x=%d\n", mb_y, mb_x);
                        return -1;
                    }
//		    dprintf("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);
                    s->idct_put(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;
}

static int 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;

    /* XXX: verify len field validity */
    len = get_bits(&s->gb, 16);
    nb_components = get_bits(&s->gb, 8);
    if (len != 6+2*nb_components)
    {
	dprintf("decode_sos: invalid len (%d)\n", len);
	return -1;
    }
    /* XXX: only interleaved scan accepted */
    if (nb_components != s->nb_components)
    {
	dprintf("decode_sos: components(%d) mismatch\n", nb_components);
        return -1;
    }
    vmax = 0;
    hmax = 0;
    for(i=0;i<nb_components;i++) {
        id = get_bits(&s->gb, 8) - 1;
	dprintf("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)
	{
	    dprintf("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;
#if 0 //buggy
	switch(s->start_code)
	{
	    case SOF0:
		if (dc_index[i] > 1 || ac_index[i] > 1)
		    goto out_of_range;
		break;
	    case SOF1:
	    case SOF2:
		if (dc_index[i] > 3 || ac_index[i] > 3)
		    goto out_of_range;
		break;
	    case SOF3:
		if (dc_index[i] > 3 || ac_index[i] != 0)
		    goto out_of_range;
		break;	
	}
#endif
    }

    predictor= get_bits(&s->gb, 8); /* lossless predictor or start of spectral (Ss) */
    skip_bits(&s->gb, 8); /* Se */
    skip_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 {
        h = s->h_max / s->h_scount[s->comp_index[0]];
        v = s->v_max / s->v_scount[s->comp_index[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\n", s->lossless ? "lossless" : "sequencial DCT", s->rgb ? "RGB" : "", predictor, point_transform);
    
    /* 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->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) < 0)
            return -1;
    }
    emms_c();
    return 0;
 out_of_range:
    dprintf("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;
    dprintf("restart interval: %d\n", s->restart_interval);

    return 0;
}

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

    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"))
    {
	/* structure:
	    4bytes	AVI1
	    1bytes	polarity
	    1bytes	always zero
	    4bytes	field_size
	    4bytes	field_size_less_padding
	*/
    	s->buggy_avid = 1;
//	if (s->first_picture)
//	    printf("mjpeg: workarounding buggy AVID\n");
	s->interlace_polarity = get_bits(&s->gb, 8);
#if 0
	skip_bits(&s->gb, 8);
	skip_bits(&s->gb, 32);
	skip_bits(&s->gb, 32);
	len -= 10;
#endif
//	if (s->interlace_polarity)
//	    printf("mjpeg: interlace polarity: %d\n", s->interlace_polarity);
	goto out;
    }
    
//    len -= 2;
    
    if (id == ff_get_fourcc("JFIF"))
    {
	int t_w, t_h, v1, v2;
	skip_bits(&s->gb, 8); /* the trailing zero-byte */
	v1= get_bits(&s->gb, 8);
        v2= get_bits(&s->gb, 8);
        skip_bits(&s->gb, 8);

        s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 16);
        s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 16);

        if (s->avctx->debug & FF_DEBUG_PICT_INFO)
            av_log(s->avctx, AV_LOG_INFO, "mjpeg: JFIF header found (version: %x.%x) SAR=%d/%d\n",
                v1, v2,
                s->avctx->sample_aspect_ratio.num,
                s->avctx->sample_aspect_ratio.den
            );

	t_w = get_bits(&s->gb, 8);
	t_h = get_bits(&s->gb, 8);
	if (t_w && t_h)
	{
	    /* skip thumbnail */
	    if (len-10-(t_w*t_h*3) > 0)
		len -= t_w*t_h*3;
	}
	len -= 10;
	goto out;
    }
    
    if (id == ff_get_fourcc("Adob") && (get_bits(&s->gb, 8) == 'e'))
    {
        if (s->avctx->debug & FF_DEBUG_PICT_INFO)
            av_log(s->avctx, AV_LOG_INFO, "mjpeg: Adobe header found\n");
	skip_bits(&s->gb, 16); /* version */
	skip_bits(&s->gb, 16); /* flags0 */
	skip_bits(&s->gb, 16); /* flags1 */
	skip_bits(&s->gb, 8); /* transform */
	len -= 7;
	goto out;
    }

    if (id == ff_get_fourcc("LJIF")){
        if (s->avctx->debug & FF_DEBUG_PICT_INFO)
            av_log(s->avctx, AV_LOG_INFO, "Pegasus lossless jpeg header found\n");
	skip_bits(&s->gb, 16); /* version ? */
	skip_bits(&s->gb, 16); /* unknwon always 0? */