mjpeg.c

来自「linux下的MPEG1」· C语言 代码 · 共 2,030 行 · 第 1/5 页

            }
            /* (< 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;
    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)
    {
        dprintf("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;
        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); /* 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){
//            for(){
//            reset_ls_coding_parameters(s, 0);

            ls_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:
    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? */
        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->avctx->debug & FF_DEBUG_PICT_INFO)
                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)
{
    int len = get_bits(&s->gb, 16);
    if (len >= 2 && 8*len - 16 + get_bits_count(&s->gb) <= s->gb.size_in_bits) {
        char *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;

            if(s->avctx->debug & FF_DEBUG_PICT_INFO)
                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");
            }
            else if(!strcmp(cbuf, "CS=ITU601")){
                s->cs_itu601= 1;
            }

            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) && buf_ptr < buf_end) {
            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;

    buf_ptr = buf;
    buf_end = buf + buf_size;
    while (buf_ptr < buf_end) {
        /* find start next marker */
        start_code = find_marker(&buf_ptr, buf_end);
        {
            /* EOF */
            if (start_code < 0) {
                goto the_end;
            } else {
                dprintf("marker=%x avail_size_in_buf=%d\n", start_code, buf_end - buf_ptr);

                if ((buf_end - buf_ptr) > s->buffer_size)
                {
                    av_free(s->buffer);
                    s->buffer_size = buf_end-buf_ptr;
                    s->buffer = av_malloc(s->buffer