mjpeg.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

                    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;
                    if (s->interlaced && s->bottom_field)
                        ptr += s->linesize[c] >> 1;
//printf("%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 != 3)
    {
	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);
    
    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);
    dprintf("restart interval: %d\n", s->restart_interval);

    return 0;
}

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

    /* XXX: verify len field validity */
    len = get_bits(&s->gb, 16);
    if (len < 5)
	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;
	skip_bits(&s->gb, 8); /* the trailing zero-byte */
	av_log(s->avctx, AV_LOG_INFO, "mjpeg: JFIF header found (version: %x.%x)\n",
	    get_bits(&s->gb, 8), 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);

	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'))
    {
	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")){
        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? */
	skip_bits(&s->gb, 16); /* unknwon always 0? */
	skip_bits(&s->gb, 16); /* unknwon always 0? */
        switch( get_bits(&s->gb, 8)){
        case 1:
            s->rgb= 1;
            s->pegasus_rct=0;
            break;
        case 2:
            s->rgb= 1;
            s->pegasus_rct=1;
            break;
        default:
            av_log(s->avctx, AV_LOG_ERROR, "unknown colorspace\n");
        }
        len -= 9;
        goto out;
    }
    
    /* Apple MJPEG-A */
    if ((s->start_code == APP1) && (len > (0x28 - 8)))
    {
	id = (get_bits(&s->gb, 16) << 16) | get_bits(&s->gb, 16);
	id = be2me_32(id);
	len -= 4;
	if (id == ff_get_fourcc("mjpg")) /* Apple MJPEG-A */
	{
#if 0
	    skip_bits(&s->gb, 32); /* field size */
	    skip_bits(&s->gb, 32); /* pad field size */
	    skip_bits(&s->gb, 32); /* next off */
	    skip_bits(&s->gb, 32); /* quant off */
	    skip_bits(&s->gb, 32); /* huff off */
	    skip_bits(&s->gb, 32); /* image off */
	    skip_bits(&s->gb, 32); /* scan off */
	    skip_bits(&s->gb, 32); /* data off */
#endif
	    if (s->first_picture)
		av_log(s->avctx, AV_LOG_INFO, "mjpeg: Apple MJPEG-A header found\n");
	}
    }

out:
    /* slow but needed for extreme adobe jpegs */
    if (len < 0)
	av_log(s->avctx, AV_LOG_ERROR, "mjpeg: error, decode_app parser read over the end\n");
    while(--len > 0)
	skip_bits(&s->gb, 8);

    return 0;
}

static int mjpeg_decode_com(MJpegDecodeContext *s)
{
    /* XXX: verify len field validity */
    int len = get_bits(&s->gb, 16);
    if (len >= 2 && len < 32768) {
	/* XXX: any better upper bound */
	uint8_t *cbuf = av_malloc(len - 1);
	if (cbuf) {
	    int i;
	    for (i = 0; i < len - 2; i++)
		cbuf[i] = get_bits(&s->gb, 8);
	    if (i > 0 && cbuf[i-1] == '\n')
		cbuf[i-1] = 0;
	    else
		cbuf[i] = 0;

	    av_log(s->avctx, AV_LOG_INFO, "mjpeg comment: '%s'\n", cbuf);

	    /* buggy avid, it puts EOI only at every 10th frame */
	    if (!strcmp(cbuf, "AVID"))
	    {
		s->buggy_avid = 1;
		//	if (s->first_picture)
		//	    printf("mjpeg: workarounding buggy AVID\n");
	    }

	    av_free(cbuf);
	}
    }

    return 0;
}

#if 0
static int valid_marker_list[] =
{
        /* 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, a, b, c, d, e, f */
/* 0 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 1 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 2 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 3 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 4 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 5 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 6 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 7 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 8 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* 9 */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* a */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* b */    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
/* c */    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
/* d */    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
/* e */    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
/* f */    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
}
#endif

/* return the 8 bit start code value and update the search
   state. Return -1 if no start code found */
static int find_marker(uint8_t **pbuf_ptr, uint8_t *buf_end)
{
    uint8_t *buf_ptr;
    unsigned int v, v2;
    int val;
#ifdef DEBUG
    int skipped=0;
#endif

    buf_ptr = *pbuf_ptr;
    while (buf_ptr < buf_end) {
        v = *buf_ptr++;
	v2 = *buf_ptr;
        if ((v == 0xff) && (v2 >= 0xc0) && (v2 <= 0xfe)) {
	    val = *buf_ptr++;
	    goto found;
        }
#ifdef DEBUG
	skipped++;
#endif
    }
    val = -1;
found:
#ifdef DEBUG
    dprintf("find_marker skipped %d bytes\n", skipped);
#endif
    *pbuf_ptr = buf_ptr;
    return val;
}

static int mjpeg_decode_frame(AVCodecContext *avctx, 
                              void *data, int *data_size,
                              uint8_t *buf, int buf_size)
{
    MJpegDecodeContext *s = avctx->priv_data;
    uint8_t *buf_end, *buf_ptr;
    int start_code;
    AVFrame *picture = data;