mjpeg.c

tcpmp播放器的flv插件

	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) {
	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;

            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_size + FF_INPUT_BUFFER_PADDING_SIZE);
		    dprintf("buffer too small, expanding to %d bytes\n",
			s->buffer_size);
		}
		
		/* unescape buffer of SOS */
		if (start_code == SOS)
		{
		    uint8_t *src = buf_ptr;
		    uint8_t *dst = s->buffer;

		    while (src<buf_end)
		    {
			uint8_t x = *(src++);

			*(dst++) = x;
			if (x == 0xff)
			{
                            while(src<buf_end && x == 0xff)
                                x = *(src++);

			    if (x >= 0xd0 && x <= 0xd7)
				*(dst++) = x;
			    else if (x)
				break;
			}
		    }
		    init_get_bits(&s->gb, s->buffer, (dst - s->buffer)*8);
		    
		    dprintf("escaping removed %d bytes\n",
			(buf_end - buf_ptr) - (dst - s->buffer));
		}
		else
		    init_get_bits(&s->gb, buf_ptr, (buf_end - buf_ptr)*8);
		
		s->start_code = start_code;
                if(s->avctx->debug & FF_DEBUG_STARTCODE){
                    av_log(s->avctx, AV_LOG_DEBUG, "startcode: %X\n", start_code);
                }

		/* process markers */
		if (start_code >= 0xd0 && start_code <= 0xd7) {
		    dprintf("restart marker: %d\n", start_code&0x0f);
		    /* APP fields */
		} else if (start_code >= APP0 && start_code <= APP15) {
		    mjpeg_decode_app(s);
		    /* Comment */
		} else if (start_code == COM){
		    mjpeg_decode_com(s);
		}

                switch(start_code) {
                case SOI:
		    s->restart_interval = 0;
		    s->restart_count = 0;
                    /* nothing to do on SOI */
                    break;
                case DQT:
                    mjpeg_decode_dqt(s);
                    break;
                case DHT:
                    if(mjpeg_decode_dht(s) < 0){
                        av_log(s->avctx, AV_LOG_ERROR, "huffman table decode error\n");
                        return -1;
                    }
                    break;
                case SOF0:
                    s->lossless=0;
                    if (mjpeg_decode_sof(s) < 0) 
			return -1;
                    break;
                case SOF3:
                    s->lossless=1;
                    if (mjpeg_decode_sof(s) < 0) 
			return -1;
                    break;
		case EOI:
		    if ((s->buggy_avid && !s->interlaced) || s->restart_interval) 
                        break;
eoi_parser:
		    {
                        if (s->interlaced) {
                            s->bottom_field ^= 1;
                            /* if not bottom field, do not output image yet */
                            if (s->bottom_field)
                                goto not_the_end;
                        }
                        *picture = s->picture;
                        *data_size = sizeof(AVFrame);

                        if(!s->lossless){
                            picture->quality= FFMAX(FFMAX(s->qscale[0], s->qscale[1]), s->qscale[2]); 
                            picture->qstride= 0;
                            picture->qscale_table= s->qscale_table;
                            memset(picture->qscale_table, picture->quality, (s->width+15)/16);
                            if(avctx->debug & FF_DEBUG_QP)
                                av_log(s->avctx, AV_LOG_DEBUG, "QP: %d\n", picture->quality);
                            picture->quality*= FF_QP2LAMBDA;
                        }
                        
                        goto the_end;
                    }
		    break;
                case SOS:
                    mjpeg_decode_sos(s);
		    /* buggy avid puts EOI every 10-20th frame */
		    /* if restart period is over process EOI */
		    if ((s->buggy_avid && !s->interlaced) || s->restart_interval)
			goto eoi_parser;
                    break;
		case DRI:
		    mjpeg_decode_dri(s);
		    break;
		case SOF1:
		case SOF2:
		case SOF5:
		case SOF6:
		case SOF7:
		case SOF9:
		case SOF10:
		case SOF11:
		case SOF13:
		case SOF14:
		case SOF15:
		case JPG:
		    av_log(s->avctx, AV_LOG_ERROR, "mjpeg: unsupported coding type (%x)\n", start_code);
		    break;
//		default:
//		    printf("mjpeg: unsupported marker (%x)\n", start_code);
//		    break;
                }

not_the_end:
		/* eof process start code */
		buf_ptr += (get_bits_count(&s->gb)+7)/8;
		dprintf("marker parser used %d bytes (%d bits)\n",
		    (get_bits_count(&s->gb)+7)/8, get_bits_count(&s->gb));
            }
        }
    }
the_end:
    dprintf("mjpeg decode frame unused %d bytes\n", buf_end - buf_ptr);
//    return buf_end - buf_ptr;
    return buf_ptr - buf;
}

static int mjpegb_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;
    AVFrame *picture = data;
    GetBitContext hgb; /* for the header */
    uint32_t dqt_offs, dht_offs, sof_offs, sos_offs, second_field_offs;
    uint32_t field_size, sod_offs;

    buf_ptr = buf;
    buf_end = buf + buf_size;
    
read_header:
    /* reset on every SOI */
    s->restart_interval = 0;
    s->restart_count = 0;
    s->mjpb_skiptosod = 0;

    init_get_bits(&hgb, buf_ptr, /*buf_size*/(buf_end - buf_ptr)*8);

    skip_bits(&hgb, 32); /* reserved zeros */
    
    if (get_bits_long(&hgb, 32) != be2me_32(ff_get_fourcc("mjpg")))
    {
	dprintf("not mjpeg-b (bad fourcc)\n");
	return 0;
    }

    field_size = get_bits_long(&hgb, 32); /* field size */
    dprintf("field size: 0x%x\n", field_size);
    skip_bits(&hgb, 32); /* padded field size */
    second_field_offs = get_bits_long(&hgb, 32);
    dprintf("second field offs: 0x%x\n", second_field_offs);
    if (second_field_offs)
	s->interlaced = 1;

    dqt_offs = get_bits_long(&hgb, 32);
    dprintf("dqt offs: 0x%x\n", dqt_offs);
    if (dqt_offs)
    {
	init_get_bits(&s->gb, buf+dqt_offs, (buf_end - (buf+dqt_offs))*8);
	s->start_code = DQT;
	mjpeg_decode_dqt(s);
    }
    
    dht_offs = get_bits_long(&hgb, 32);
    dprintf("dht offs: 0x%x\n", dht_offs);
    if (dht_offs)
    {
	init_get_bits(&s->gb, buf+dht_offs, (buf_end - (buf+dht_offs))*8);
	s->start_code = DHT;
	mjpeg_decode_dht(s);
    }

    sof_offs = get_bits_long(&hgb, 32);
    dprintf("sof offs: 0x%x\n", sof_offs);
    if (sof_offs)
    {
	init_get_bits(&s->gb, buf+sof_offs, (buf_end - (buf+sof_offs))*8);
	s->start_code = SOF0;
	if (mjpeg_decode_sof(s) < 0)
	    return -1;
    }

    sos_offs = get_bits_long(&hgb, 32);
    dprintf("sos offs: 0x%x\n", sos_offs);
    sod_offs = get_bits_long(&hgb, 32);
    dprintf("sod offs: 0x%x\n", sod_offs);
    if (sos_offs)
    {
//	init_get_bits(&s->gb, buf+sos_offs, (buf_end - (buf+sos_offs))*8);
	init_get_bits(&s->gb, buf+sos_offs, field_size*8);
	s->mjpb_skiptosod = (sod_offs - sos_offs - show_bits(&s->gb, 16));
	s->start_code = SOS;
	mjpeg_decode_sos(s);
    }

    if (s->interlaced) {
        s->bottom_field ^= 1;
        /* if not bottom field, do not output image yet */
        if (s->bottom_field && second_field_offs)
	{
	    buf_ptr = buf + second_field_offs;
	    second_field_offs = 0;
	    goto read_header;
    	}
    }

    //XXX FIXME factorize, this looks very similar to the EOI code

    *picture= s->picture;
    *data_size = sizeof(AVFrame);
    
    if(!s->lossless){
        picture->quality= FFMAX(FFMAX(s->qscale[0], s->qscale[1]), s->qscale[2]); 
        picture->qstride= 0;
        picture->qscale_table= s->qscale_table;
        memset(picture->qscale_table, picture->quality, (s->width+15)/16);
        if(avctx->debug & FF_DEBUG_QP)
            av_log(avctx, AV_LOG_DEBUG, "QP: %d\n", picture->quality);