parse-mpeg.c

It s a tool designed to extract as much information as possible from Bluetooth devices without the r

	if (ng_debug > 1)
	    fprintf(stderr,"pts: %8.3f | id 0x%02x %s\n",
		    pts/90000.0,id,pes_s[id]);
	if (ts)
	    *ts = pts;
    }
    return size;
}

int mpeg_get_audio_rate(unsigned char *header)
{
    int rate = 44100;

    if (mpeg_getbits(header,12,1) == 1) {
	/* MPEG 1.0 */
	switch (mpeg_getbits(header,20,2)) {
	case 0: rate  = 44100; break;
	case 1: rate  = 48000; break;
	case 2: rate  = 32000; break;
	}
	if (ng_debug)
	    fprintf(stderr,"mpeg: MPEG1 audio, rate %d\n",rate);
    } else {
	/* MPEG 2.0 */
	switch (mpeg_getbits(header,20,2)) {
	case 0: rate  = 22050; break;
	case 1: rate  = 24000; break;
	case 2: rate  = 16000; break;
	}
	if (ng_debug)
	    fprintf(stderr,"mpeg: MPEG2 audio, rate %d\n",rate);
    }
    return rate;
}

unsigned char* mpeg_find_audio_hdr(unsigned char *buf, int off, int size)
{
    int i;
    
    for (i = off; i < size-1; i++) {
	if (0xff != buf[i])
	    continue;
	if (0xf0 == (buf[i+1] & 0xf0))
	    return buf+i;
    }
    return NULL;
}

int mpeg_get_video_fmt(struct mpeg_handle *h, unsigned char *header)
{
    if (header[0] != 0x00  ||  header[1] != 0x00  ||
	header[2] != 0x01  ||  header[3] != 0xb3)
	return -1;
    h->vfmt.fmtid  = VIDEO_MPEG;
    h->vfmt.width  = (mpeg_getbits(header,32,12) + 15) & ~15;
    h->vfmt.height = (mpeg_getbits(header,44,12) + 15) & ~15;
    h->ratio  = mpeg_getbits(header,56,4);
    h->rate   = mpeg_getbits(header,60,4);
    if (ng_debug)
	fprintf(stderr,"mpeg: MPEG video, %dx%d [ratio=%s,rate=%s]\n",
		h->vfmt.width, h->vfmt.height,
		ratio_s[h->ratio], rate_s[h->rate]);
    return 0;
}

int mpeg_check_video_fmt(struct mpeg_handle *h, unsigned char *header)
{
    int width, height, ratio;
    int change = 0;

    if (header[0] != 0x00  ||  header[1] != 0x00  ||
	header[2] != 0x01  ||  header[3] != 0xb3)
	return 0;
    width  = (mpeg_getbits(header,32,12) + 15) & ~15;
    height = (mpeg_getbits(header,44,12) + 15) & ~15;
    ratio  = mpeg_getbits(header,56,4);
    if (width != h->vfmt.width || height != h->vfmt.height) {
	if (ng_debug)
	    fprintf(stderr,"mpeg: size change: %dx%d => %dx%d\n",
		    h->vfmt.width, h->vfmt.height, width, height);
	change++;
    }
    if (ratio != h->ratio) {
	if (ng_debug)
	    fprintf(stderr,"mpeg: ratio change: %s => %s\n",
		    ratio_s[h->ratio], ratio_s[ratio]);
	change++;
    }
    h->vfmt.height = height;
    h->vfmt.width  = width;
    h->ratio       = ratio;
    return change;
}

/* ----------------------------------------------------------------------- */
/* program streams                                                         */

size_t mpeg_find_ps_packet(struct mpeg_handle *h, int packet, int mask, off_t *pos)
{
    unsigned char *buf;
    size_t size;
    off_t start = *pos;

    /* read header */
    for (;;) {
	buf = mpeg_get_data(h,*pos,16);
	if (NULL == buf)
	    return 0;
	if (buf[0] != 0x00 ||
	    buf[1] != 0x00 ||
	    buf[2] != 0x01)
	    return 0;
	size = mpeg_getbits(buf,32,16) + 6;

	/* handle special cases */
	switch (buf[3]) {
	case 0xba:
	    /* packet start code */
	    if (0x01 == mpeg_getbits(buf,32,2)) {
		/* MPEG 2 */
		size = 14 + mpeg_getbits(buf,109,3);
	    } else if (0x02 == mpeg_getbits(buf,32,4)) {
		/* MPEG 1 */
		size = 12;
	    } else {
		/* Huh? */
		return 0;
	    }
	    break;
	case 0xb9:
	    /* mpeg program end code */
	    return 0;
	}
	if (ng_debug > 1)
	    fprintf(stderr,"mpeg: packet 0x%x at 0x%08" PRIx64 "+%d [need 0x%x]\n",
		    (int)buf[3],(int64_t)*pos,(int)size,packet);

	/* our packet ? */
	if ((buf[3] & mask) == packet)
	    return size;
	*pos += size;

	/* don't search unlimited ... */
	if (*pos - start > FILE_BUF_MIN)
	    return 0;
    }
}

/* ----------------------------------------------------------------------- */
/* transport streams                                                       */

static void parse_pmt_desc(unsigned char *desc, int dlen,
			   struct psi_program *program, int pid)
{
    int i,t,l;

    for (i = 0; i < dlen; i += desc[i+1] +2) {
	t = desc[i];
	l = desc[i+1];

	switch (t) {
	case 0x56:
	    if (!program->t_pid)
		program->t_pid = pid;
	    break;
	}
    }
}

static char* get_lang_tag(unsigned char *desc, int dlen)
{
    int i,t,l;

    for (i = 0; i < dlen; i += desc[i+1] +2) {
	t = desc[i];
	l = desc[i+1];

	if (0x0a == t)
	    return desc+i+2;
    }
    return NULL;
}

static void dump_data(unsigned char *data, int len)
{
    int i;
    
    for (i = 0; i < len; i++) {
	if (isprint(data[i]))
	    fprintf(stderr,"%c", data[i]);
	else
	    fprintf(stderr,"\\x%02x", (int)data[i]);
    }
}

void mpeg_dump_desc(unsigned char *desc, int dlen)
{
    int i,j,t,l,l2,l3;

    for (i = 0; i < dlen; i += desc[i+1] +2) {
	t = desc[i];
	l = desc[i+1];

	switch (t) {
	case 0x0a: /* ??? (pmt) */
	    fprintf(stderr," lang=%3.3s",desc+i+2);
	    break;
	case 0x45: /* vbi data (pmt) */
	    fprintf(stderr," vbidata=");
	    dump_data(desc+i+2,l);
	    break;
	case 0x52: /* stream identifier */
	    fprintf(stderr," sid=%d",(int)desc[i+2]);
	    break;
	case 0x56: /* teletext (pmt) */
	    fprintf(stderr," teletext=%3.3s",desc+i+2);
	    break;
	case 0x59: /* subtitles (pmt) */
	    fprintf(stderr," subtitles=%3.3s",desc+i+2);
	    break;
	case 0x6a: /* ac3 (pmt) */
	    fprintf(stderr," ac3");
	    break;

	case 0x40: /* network name (nit) */
	    fprintf(stderr," name=");
	    dump_data(desc+i+2,l);
	    break;
	case 0x43: /* satellite delivery system (nit) */
	    fprintf(stderr," dvb-s");
	    break;
	case 0x44: /* cable delivery system (nit) */
	    fprintf(stderr," dvb-c");
	    break;
	case 0x5a: /* terrestrial delivery system (nit) */
	    fprintf(stderr," dvb-t");
	    break;

	case 0x48: /* service (sdt) */
	    fprintf(stderr," service=%d,",desc[i+2]);
	    l2 = desc[i+3];
	    dump_data(desc+i+4,desc[i+3]);
	    fprintf(stderr,",");
	    dump_data(desc+i+l2+5,desc[i+l2+4]);
	    break;

	case 0x4d: /*  event (eid) */
	    fprintf(stderr," short=[%3.3s|",desc+i+2);
	    l2 = desc[i+5];
	    l3 = desc[i+6+l2];
	    dump_data(desc+i+6,l2);
	    fprintf(stderr,"|");
	    dump_data(desc+i+7+l2,l3);
	    fprintf(stderr,"]");
	    break;
	case 0x4e: /*  event (eid) */
	    fprintf(stderr," *ext event");
	    break;
	case 0x4f: /*  event (eid) */
	    fprintf(stderr," *time shift event");
	    break;
	case 0x50: /*  event (eid) */
	    fprintf(stderr," *component");
	    break;
	case 0x54: /*  event (eid) */
	    fprintf(stderr," content=");
	    for (j = 0; j < l; j+=2)
		fprintf(stderr,"%s0x%02x", j ? "," : "", desc[i+j+2]);
	    break;
	case 0x55: /*  event (eid) */
	    fprintf(stderr," *parental rating");
	    break;
	    
	default:
	    fprintf(stderr," %02x[",desc[i]);
	    dump_data(desc+i+2,l);
	    fprintf(stderr,"]");
	}
    }
}

int mpeg_parse_psi_pat(struct psi_info *info, unsigned char *data, int verbose)
{
    struct list_head   *item;
    struct psi_program *pr;
    int tsid,pnr,version,current;
    int j,len,pid;

    len     = mpeg_getbits(data,12,12) + 3 - 4;
    tsid    = mpeg_getbits(data,24,16);
    version = mpeg_getbits(data,42,5);
    current = mpeg_getbits(data,47,1);
    if (!current)
	return len+4;
    if (info->tsid == tsid && info->pat_version == version)
	return len+4;
    info->tsid         = tsid;
    info->pat_version  = version;
    info->pat_updated  = 1;
    
    if (verbose)
	fprintf(stderr, "ts [pat]: tsid %d ver %2d [%d/%d]\n",
		tsid, version,
		mpeg_getbits(data,48, 8),
		mpeg_getbits(data,56, 8));
    for (j = 64; j < len*8; j += 32) {
	pnr    = mpeg_getbits(data,j+0,16);
	pid    = mpeg_getbits(data,j+19,13);
	if (0 == pnr) {
	    /* network */
	    if (verbose > 1)
		fprintf(stderr,"   pid 0x%04x [network]\n",
			pid);
	} else {
	    /* program */
	    pr = psi_program_get(info, tsid, pnr, 1);
	    pr->p_pid   = pid;
	    pr->updated = 1;
	    pr->seen    = 1;
	    if (NULL == info->pr)
		info->pr = pr;
	}
    }
    if (verbose > 1) {
	list_for_each(item,&info->programs) {
	    pr = list_entry(item, struct psi_program, next);
	    if (pr->tsid != tsid)
		continue;
	    fprintf(stderr,"   pid 0x%04x => pnr %2d [program map%s]\n",
		    pr->p_pid, pr->pnr,
		    pr->seen ? ",seen" : "");
	}
	fprintf(stderr,"\n");
    }
    return len+4;
}

int mpeg_parse_psi_pmt(struct psi_program *program, unsigned char *data, int verbose)
{
    int pnr,version,current;
    int j,len,dlen,type,pid,slen;
    char *lang;

    len     = mpeg_getbits(data,12,12) + 3 - 4;
    pnr     = mpeg_getbits(data,24,16);
    version = mpeg_getbits(data,42,5);
    current = mpeg_getbits(data,47,1);
    if (!current)
	return len+4;
    if (program->pnr == pnr && program->version == version)
	return len+4;
    program->version = version;
    program->updated = 1;

    dlen = mpeg_getbits(data,84,12);
    /* TODO: decode descriptor? */
    if (verbose) {
	fprintf(stderr,
		"ts [pmt]: pnr %d ver %2d [%d/%d]  pcr 0x%04x  "
		"pid 0x%04x  type %2d #",
		pnr, version,
		mpeg_getbits(data,48, 8),
		mpeg_getbits(data,56, 8),
		mpeg_getbits(data,69,13),
		program->p_pid, program->type);
	mpeg_dump_desc(data + 96/8, dlen);
	fprintf(stderr,"\n");
    }
    j = 96 + dlen*8;
    program->v_pid = 0;
    program->a_pid = 0;
    program->t_pid = 0;
    memset(program->audio,0,sizeof(program->audio));
    while (j < len*8) {
	type = mpeg_getbits(data,j,8);
	pid  = mpeg_getbits(data,j+11,13);
	dlen = mpeg_getbits(data,j+28,12);
	switch (type) {
	case 1:
	case 2:
	    /* video */
	    if (!program->v_pid)
		program->v_pid = pid;
	    break;
	case 3:
	case 4:
	    /* audio */
	    if (!program->a_pid)
		program->a_pid = pid;
	    lang = get_lang_tag(data + (j+40)/8, dlen);
	    slen = strlen(program->audio);
	    snprintf(program->audio + slen, sizeof(program->audio) - slen,
		     "%s%.3s:%d", slen ? " " : "", lang ? lang : "xxx", pid);
	    break;
	case 6:
	    /* private data */
	    parse_pmt_desc(data + (j+40)/8, dlen, program, pid);
	    break;
	}
	if (verbose > 1) {
	    fprintf(stderr, "   pid 0x%04x => %-32s #",
		    pid, stream_type_s[type]);
	    mpeg_dump_desc(data + (j+40)/8, dlen);
	    fprintf(stderr,"\n");
	}
	j += 40 + dlen*8;
    }
    if (verbose > 1)
	fprintf(stderr,"\n");
    return len+4;
}

int mpeg_parse_psi(struct psi_info *info, struct mpeg_handle *h, int verbose)
{
    int i,tid;

    if (h->ts.payload) {
	for (i = h->ts.data[0]+1; i < h->ts.size;) {
	    tid = mpeg_getbits(h->ts.data,i*8,8);
	    switch (tid) {
	    case 0:
		i += mpeg_parse_psi_pat(info, h->ts.data+i, verbose);
		break;
	    case 1:
		fprintf(stderr, "ts: conditional access\n");
		return 0;
	    case 2:
		i += mpeg_parse_psi_pmt(info->pr, h->ts.data+i, verbose);
		break;
	    case 3:
		fprintf(stderr, "ts: description\n");
		return 0;
	    case 0xff:
		/* end of data */
		return 0;
	    default:
		fprintf(stderr, "ts: unknown table id %d\n",tid);
		return 0;
	    }
	}
    }
    return 0;
}

/* ----------------------------------------------------------------------- */

int mpeg_find_ts_packet(struct mpeg_handle *h, int wanted, off_t *pos)
{
    unsigned char *packet;
    int asize = 0;
    off_t start;

    for (start = *pos; *pos - start < FILE_BUF_MIN; *pos += TS_SIZE) {
	memset(&h->ts, 0, sizeof(h->ts));
	packet = mpeg_get_data(h, *pos, TS_SIZE);
	if (NULL == packet) {
	    fprintf(stderr,"mpeg ts: no more data\n");
	    return -1;
	}
	if (packet[0] != 0x47) {
	    if (ng_log_bad_stream)
		fprintf(stderr,"mpeg ts: warning %d: packet id mismatch\n",
			h->errors);
	    h->errors++;
	    continue;
	}
	h->ts.tei      = mpeg_getbits(packet, 8,1);
	h->ts.payload  = mpeg_getbits(packet, 9,1);
	h->ts.pid      = mpeg_getbits(packet,11,13);
	h->ts.scramble = mpeg_getbits(packet,24,2);
	h->ts.adapt    = mpeg_getbits(packet,26,2);
	h->ts.cont     = mpeg_getbits(packet,28,4);
	if (0 == h->ts.adapt)
	    /* reserved -- should discard */
	    continue;
	if (0x1fff == h->ts.pid)
	    /* NULL packet -- discard */
	    continue;
	if (h->ts.pid != wanted)
	    /* need something else */
	    continue;
	switch (h->ts.adapt) {
	case 3:
	    /* adaptation + payload */
	    asize      = mpeg_getbits(packet,32,8) +1;
	    h->ts.data = packet  + (4 + asize);
	    h->ts.size = TS_SIZE - (4 + asize);
	    if (h->ts.size > TS_SIZE) {
		if (ng_log_bad_stream)
		    fprintf(stderr,"mpeg ts: warning %d: broken adaptation"
			    " size [%lx]\n",h->errors,(unsigned long)(*pos));
		h->errors++;
		continue;
	    }
	    /* fall throuth */
	case 2:
	    /* adaptation only */
	    /* TODO: parse adaptation field */
	    break;
	case 1:
	    /* payload only */
	    h->ts.data = packet  + 4;
	    h->ts.size = TS_SIZE - 4;
	    break;
	}
	if (ng_debug > 2)
	    fprintf(stderr,"mpeg ts: pl=%d pid=%d adapt=%d cont=%d size=%d [%d]\n",
		    h->ts.payload, h->ts.pid, h->ts.adapt,
		    h->ts.cont, h->ts.size, asize);
	return 0;
    }
    return -1;
}