Imported Upstream version 1.1.1+rev1207upstream/1.1.1+rev1207

1 files changed, 256 insertions, 0 deletions

diff --git a/lib/libucsi/transport_packet.c b/lib/libucsi/transport_packet.c
new file mode 100644
index 0000000..ca6c2e1
--- /dev/null
+++ b/lib/libucsi/transport_packet.c
@@ -0,0 +1,256 @@
+/*
+ * section and descriptor parser
+ *
+ * Copyright (C) 2005 Andrew de Quincey (adq_dvb@lidskialf.net)
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#include "transport_packet.h"
+
+#define CONTINUITY_VALID 0x80
+#define CONTINUITY_DUPESEEN 0x40
+
+int transport_packet_values_extract(struct transport_packet *pkt,
+				    struct transport_values *out,
+ 				    enum transport_value extract)
+{
+	uint8_t *end = (uint8_t*) pkt + TRANSPORT_PACKET_LENGTH;
+	uint8_t *adapend;
+	uint8_t *pos = (uint8_t*) pkt + sizeof(struct transport_packet);
+	enum transport_value extracted = 0;
+	enum transport_adaptation_flags adapflags = 0;
+	enum transport_adaptation_extension_flags adapextflags = 0;
+	int adaplength = 0;
+	int adapextlength = 0;
+
+	/* does the packet contain an adaptation field ? */
+	if ((pkt->adaptation_field_control & 2) == 0)
+		goto extract_payload;
+
+	/* get the adaptation field length and skip the byte */
+	adaplength = *pos++;
+
+	/* do we actually have any adaptation data? */
+	if (adaplength == 0)
+		goto extract_payload;
+
+	/* sanity check */
+	adapend = pos + adaplength;
+	if (adapend > end)
+		return -1;
+
+	/* extract the adaptation flags (we must have at least 1 byte to be here) */
+	adapflags = *pos++;
+
+	/* do we actually want anything else? */
+	if ((extract & 0xffff) == 0)
+		goto extract_payload;
+
+	/* PCR? */
+	if (adapflags & transport_adaptation_flag_pcr) {
+		if ((pos+6) > adapend)
+			return -1;
+
+		if (extract & transport_value_pcr) {
+			uint64_t base = ((uint64_t) pos[0] << 25) |
+					((uint64_t) pos[1] << 17) |
+					((uint64_t) pos[2] << 9) |
+					((uint64_t) pos[3] << 1) |
+					((uint64_t) pos[4] >> 7);
+			uint64_t ext = (((uint64_t) pos[4] & 1) << 8) |
+					(uint64_t) pos[5];
+			out->pcr= base * 300ULL + ext;
+			extracted |= transport_value_pcr;
+		}
+		pos += 6;
+	}
+
+	/* OPCR? */
+	if (adapflags & transport_adaptation_flag_opcr) {
+		if ((pos+6) > adapend)
+			return -1;
+
+		if (extract & transport_value_opcr) {
+			uint64_t base = ((uint64_t) pos[0] << 25) |
+					((uint64_t) pos[1] << 17) |
+					((uint64_t) pos[2] << 9) |
+					((uint64_t) pos[3] << 1) |
+					((uint64_t) pos[4] >> 7);
+			uint64_t ext = (((uint64_t) pos[4] & 1) << 8) |
+					(uint64_t) pos[5];
+			out->opcr= base * 300ULL + ext;
+			extracted |= transport_value_opcr;
+		}
+		pos += 6;
+	}
+
+	/* splice countdown? */
+	if (adapflags & transport_adaptation_flag_splicing_point) {
+		if ((pos+1) > adapend)
+			return -1;
+
+		if (extract & transport_value_splice_countdown) {
+			out->splice_countdown = *pos;
+			extracted |= transport_value_splice_countdown;
+		}
+		pos++;
+	}
+
+	/* private data? */
+	if (adapflags & transport_adaptation_flag_private_data) {
+		if ((pos+1) > adapend)
+			return -1;
+		if ((pos+1+*pos) > adapend)
+			return -1;
+
+		if (extract & transport_value_private_data) {
+			out->private_data_length = *pos;
+			out->private_data = pos + 1;
+			extracted |= transport_value_private_data;
+		}
+		pos += 1 + *pos;
+	}
+
+	/* is there an adaptation extension? */
+	if (!(adapflags & transport_adaptation_flag_extension))
+		goto extract_payload;
+
+	/* get/check the length */
+	if (pos >= adapend)
+		return -1;
+	adapextlength = *pos++;
+	if ((pos + adapextlength) > adapend)
+		return -1;
+
+	/* do we want/have anything in the adaptation extension? */
+	if (((extract & 0xff00) == 0) || (adapextlength == 0))
+		goto extract_payload;
+
+	/* extract the adaptation extension flags (we must have at least 1 byte
+	 * to be here) */
+	adapextflags = *pos++;
+
+	/* LTW? */
+	if (adapextflags & transport_adaptation_extension_flag_ltw) {
+		if ((pos+2) > adapend)
+			return -1;
+
+		if (extract & transport_value_ltw) {
+			if (*pos & 0x80) {
+				out->ltw_offset = ((pos[0] & 0x7f) << 8) |
+						  (pos[1]);
+				extracted |= transport_value_ltw;
+			}
+		}
+		pos += 2;
+	}
+
+	/* piecewise_rate? */
+	if (adapextflags & transport_adaptation_extension_flag_piecewise_rate) {
+		if ((pos+3) > adapend)
+			return -1;
+
+		if (extract & transport_value_piecewise_rate) {
+			out->piecewise_rate = ((pos[0] & 0x3f) << 16) |
+					      (pos[1] << 8) |
+					      pos[2];
+			extracted |= transport_value_piecewise_rate;
+		}
+		pos += 3;
+	}
+
+	/* seamless_splice? */
+	if (adapextflags & transport_adaptation_extension_flag_seamless_splice) {
+		if ((pos+5) > adapend)
+			return -1;
+
+		if (extract & transport_value_piecewise_rate) {
+			out->splice_type = pos[0] >> 4;
+			out->dts_next_au = ((pos[0] & 0x0e) << 29) |
+					   (pos[1] << 22) |
+					   ((pos[2] & 0xfe) << 14) |
+					   (pos[3] << 7) |
+					   ((pos[4] & 0xfe) >> 1);
+			extracted |= transport_value_seamless_splice;
+		}
+		pos += 5;
+	}
+
+
+
+extract_payload:
+	/* does the packet contain a payload? */
+	if (pkt->adaptation_field_control & 1) {
+		int off = sizeof(struct transport_packet);
+		if (pkt->adaptation_field_control & 2)
+			off++;
+		off += adaplength;
+
+		out->payload = (uint8_t*) pkt + off;
+		out->payload_length = TRANSPORT_PACKET_LENGTH - off;
+	} else {
+		out->payload = NULL;
+		out->payload_length = 0;
+	}
+
+	out->flags = adapflags;
+	return extracted;
+}
+
+int transport_packet_continuity_check(struct transport_packet *pkt,
+				      int discontinuity_indicator, unsigned char *cstate)
+{
+	unsigned char pktcontinuity = pkt->continuity_counter;
+	unsigned char prevcontinuity = *cstate & 0x0f;
+	unsigned char nextcontinuity;
+
+	/* NULL packets have undefined continuity */
+	if (transport_packet_pid(pkt) == TRANSPORT_NULL_PID)
+		return 0;
+
+	/* is the state valid? */
+	if (!(*cstate & CONTINUITY_VALID)) {
+		*cstate = pktcontinuity | CONTINUITY_VALID;
+		return 0;
+	}
+
+	/* check for discontinuity_indicator */
+	if (discontinuity_indicator) {
+		*cstate = pktcontinuity | CONTINUITY_VALID;
+		return 0;
+	}
+
+	/* only packets with a payload should increment the counter */
+	if (pkt->adaptation_field_control & 1)
+		nextcontinuity = (prevcontinuity + 1) & 0xf;
+	else
+		nextcontinuity = prevcontinuity;
+
+	/* check for a normal continuity progression */
+	if (nextcontinuity == pktcontinuity) {
+		*cstate = pktcontinuity | CONTINUITY_VALID;
+		return 0;
+	}
+
+	/* one dupe is allowed */
+	if ((prevcontinuity == pktcontinuity) && (!(*cstate & CONTINUITY_DUPESEEN))) {
+		*cstate = pktcontinuity | (CONTINUITY_VALID|CONTINUITY_DUPESEEN);
+		return 0;
+	}
+
+	/* continuity error */
+	return -1;
+}