dddvb/lib/dvb_filter.h

static inline uint16_t seclen(const uint8_t *buf)
{
	return 3+((buf[1]&0x0f)<<8)+buf[2];
}

static inline uint16_t tspid(const uint8_t *buf)
{
	return ((buf[1]&0x1f)<<8)+buf[2];
}

static inline int tspayload(const uint8_t *tsp)
{
	if (!(tsp[3] & 0x10))
		return 0;
	if (tsp[3] & 0x20)
		return (tsp[4] > 183) ? 0 : (183 - tsp[4]);
	return 184;
}

static inline int tspaystart(const uint8_t *tsp)
{
	if (!(tsp[3]&0x10))
		return 188;
	if (tsp[3]&0x20)
		return (tsp[4] >= 184) ? 188 : tsp[4]+5;
	return 4;
}

static uint32_t dvb_crc_table[256] = {
	0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
	0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
	0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
	0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
	0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3,
	0x709f7b7a, 0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
	0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58, 0xbaea46ef,
	0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
	0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb,
	0xceb42022, 0xca753d95, 0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
	0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
	0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
	0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4,
	0x0808d07d, 0x0cc9cdca, 0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
	0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08,
	0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
	0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc,
	0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
	0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a, 0xe0b41de7, 0xe4750050,
	0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
	0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
	0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
	0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb, 0x4f040d56, 0x4bc510e1,
	0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
	0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5,
	0x3f9b762c, 0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
	0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e, 0xf5ee4bb9,
	0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
	0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd,
	0xcda1f604, 0xc960ebb3, 0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
	0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
	0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
	0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2,
	0x470cdd2b, 0x43cdc09c, 0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
	0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e,
	0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
	0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a,
	0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
	0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c, 0xe3a1cbc1, 0xe760d676,
	0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
	0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
	0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
	0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4};

uint32_t dvb_crc32(uint8_t *data, int len)
{
	int i;
	uint32_t crc=0xffffffff;

	for (i = 0; i < len; i++)
		crc = (crc << 8) ^ dvb_crc_table[((crc >> 24) ^ *data++) & 0xff];
	return crc;
}

struct dvbf_pid {
	uint16_t pid;
	uint8_t cc;
	uint16_t bufp;
	uint16_t len;
	uint8_t buf[4096];
};

static inline void pidf_reset(struct dvbf_pid *pidf)
{
	pidf->bufp = pidf->len = 0;
}

void dvbf_init_pid(struct dvbf_pid *pidf, uint16_t pid)
{
	pidf->pid = pid;
	pidf->cc = 0xff;
	pidf_reset(pidf);
}

static inline void write_secbuf(struct dvbf_pid *p, uint8_t *tsp, int n)
{
	memcpy(p->buf+p->bufp, tsp, n);
	p->bufp += n;
}

static inline int validcc(struct dvbf_pid *p, uint8_t *tsp)
{
	uint8_t newcc;
	int valid;

	newcc = tsp[3] & 0x0f;
	if (p->cc == 0xff)
		valid=1;
	else
		valid = (((p->cc + 1) & 0x0f) == newcc) ? 1 : 0;
	p->cc = newcc;
	if (!valid) 
		pidf_reset(p);
	return valid;
}


void dump(FILE *fp, uint8_t *b, int l)
{
	int i, j;
	
	for (j = 0; j < l; j += 16, b += 16) { 
		for (i = 0; i < 16; i++)
			if (i + j < l)
				fprintf(fp, "%02x ", b[i]);
			else
				fprintf(fp, "   ");
		fprintf(fp, " | ");
		for (i = 0; i < 16; i++)
			if (i + j < l)
				fprintf(fp, "%c", (b[i] > 31 && b[i] < 127) ? b[i] : '.');
		fprintf(fp, "\n");
	}
}

static void pidf_section(struct dvbf_pid *p)
{
	dump(stderr, p->buf, p->len);
}


static int proc_pidf(struct dvbf_pid *p, uint8_t *tsp)
{
	int pusoff, todo, off;

	if (tspid(tsp) != p->pid)
		return 0;
	if (!(tsp[3] & 0x10))  //no payload
		return 0;
	todo = (tsp[3] & 0x20) ?  // AF?
		((tsp[4] > 183) ? 0 : (183 - tsp[4])) :
		184;
	if (!todo)
		return 0;
	off = 188 - todo;
	pusoff = (tsp[1] & 0x40) ? tsp[off++] : todo;
	if (pusoff + off > 188)
		goto error;
	if (validcc(p, tsp) && pusoff && p->bufp) {
		int rlen = pusoff;
		if (p->len) {
			if (p->bufp + rlen > p->len)
				rlen = p->len - p->bufp;
		} else
			if (p->bufp + rlen > 4096)
				rlen = 4096 - p->bufp;
		write_secbuf(p, tsp + off, rlen);
		if (!p->len && p->bufp >= 3 && (p->len = seclen(p->buf)) > 4096) 
			pidf_reset(p);
		else
			return 1;//pidf_section(p);
	}
	off += pusoff;
	while ((todo = 188 - off) > 0 && tsp[off] != 0xff) {
		pidf_reset(p);
		if (todo < 3 || (p->len = seclen(tsp+off)) > todo) {
			if (p->len > 4096)
				goto error;
			write_secbuf(p, tsp+off, todo);
			off+=todo;
		} else {
			write_secbuf(p, tsp+off, p->len);
			off+=p->len;
			return 2;//pidf_section(p);
		}
	}
	return 0;

error:
	pidf_reset(p);
	return -1;
}