Initial community commit

Src/nsmkv/Cues.cpp

@@ -0,0 +1,205 @@
+#include "Cues.h"
+#include "read.h"
+#include "global_elements.h"
+
+nsmkv::CuePoint *nsmkv::Cues::GetCuePoint(uint64_t when, uint64_t current_time, int seek_direction)
+{
+	CuePoint *last=0;
+	CuePoints::iterator itr;
+	for (itr=cue_points.begin(); itr!=cue_points.end();itr++)
+	{
+		CuePoint *cue_point = itr->second;
+		if (cue_point->cue_time == when)
+		{
+			if (seek_direction != SEEK_FORWARD || current_time < cue_point->cue_time)
+				return cue_point;
+		}
+		else if (cue_point->cue_time > when)
+		{
+			if (last)
+			{
+				if (seek_direction != SEEK_FORWARD || current_time < last->cue_time)
+					return last;
+			}
+			else
+				return cue_point;
+		}
+
+		last = cue_point;
+	}
+	return last; // will be 0 if we don't have any cue points, which is what we want.
+}
+
+nsmkv::CueTrackPosition *nsmkv::CuePoint::GetPosition(uint64_t track)
+{
+	CueTrackPositions::iterator found = cue_track_positions.find(track);
+	if (found != cue_track_positions.end())
+		return found->second;
+	else
+		return 0;
+}
+
+// returns bytes read.  0 means EOF
+static uint64_t ReadCueTrackPositions(nsmkv::MKVReader *reader, uint64_t size, nsmkv::CueTrackPosition &track_position)
+{
+	uint64_t total_bytes_read=0;
+	while (size)
+	{
+		ebml_node node;
+		uint64_t bytes_read = read_ebml_node(reader, &node);
+
+		if (bytes_read == 0)
+			return 0;
+
+		// benski> checking bytes_read and node.size separately prevents possible integer overflow attack
+		if (bytes_read > size)
+			return 0;
+		total_bytes_read+=bytes_read;
+		size-=bytes_read;
+
+		if (node.size > size)
+			return 0;
+		total_bytes_read+=node.size;
+		size-=node.size;
+
+		switch(node.id)
+		{
+		case mkv_cuetrackpositions_cuetrack:
+			{
+				uint64_t val;
+				if (read_unsigned(reader, node.size, &val) == 0)
+					return 0;
+
+				track_position.track = val;
+#ifdef WA_VALIDATE
+				printf("      Cue Track: %I64u\n", val);
+				track_position.track_found = true;
+#endif
+			}
+			break;
+		case mkv_cuetrackpositions_cueclusterposition:
+			{			
+				uint64_t val;
+				if (read_unsigned(reader, node.size, &val) == 0)
+					return 0;
+
+				track_position.cluster_position = val;
+#ifdef WA_VALIDATE
+				printf("      Cue Cluster Position: %I64u\n", val);
+				track_position.cluster_position_found = true;
+#endif
+			}
+			break;
+		default:
+			nsmkv::ReadGlobal(reader, node.id, node.size);
+		}
+	}
+	return total_bytes_read;
+}
+
+// returns bytes read.  0 means EOF
+static uint64_t ReadCuePoint(nsmkv::MKVReader *reader, uint64_t size, nsmkv::CuePoint &cue_point)
+{
+	uint64_t total_bytes_read=0;
+	while (size)
+	{
+		ebml_node node;
+		uint64_t bytes_read = read_ebml_node(reader, &node);
+
+		if (bytes_read == 0)
+			return 0;
+
+		// benski> checking bytes_read and node.size separately prevents possible integer overflow attack
+		if (bytes_read > size)
+			return 0;
+		total_bytes_read+=bytes_read;
+		size-=bytes_read;
+
+		if (node.size > size)
+			return 0;
+		total_bytes_read+=node.size;
+		size-=node.size;
+
+		switch(node.id)
+		{
+		case mkv_cuepoint_cuetime:
+			{
+				uint64_t val;
+				if (read_unsigned(reader, node.size, &val) == 0)
+					return 0;
+
+				cue_point.cue_time = val;
+
+#ifdef WA_VALIDATE
+				printf("    Cue Time: %I64u\n", val);
+				cue_point.cue_time_found = true;
+#endif
+			}
+			break;
+		case mkv_cuepoint_cuetrackpositions:
+			{
+#ifdef WA_VALIDATE
+				printf("    Cue Track Positions\n");
+#endif
+				nsmkv::CueTrackPosition *track_position = new nsmkv::CueTrackPosition;
+				if (ReadCueTrackPositions(reader, node.size, *track_position) == 0)
+				{
+					delete track_position;
+					return 0;
+				}
+				cue_point.cue_track_positions[track_position->track] = track_position;
+			}
+			break;
+		default:
+			nsmkv::ReadGlobal(reader, node.id, node.size);
+		}
+	}
+	return total_bytes_read;
+}
+
+// returns bytes read.  0 means EOF
+uint64_t nsmkv::ReadCues(nsmkv::MKVReader *reader, uint64_t size, nsmkv::Cues &cues)
+{
+	uint64_t total_bytes_read=0;
+	while (size)
+	{
+		ebml_node node;
+		uint64_t bytes_read = read_ebml_node(reader, &node);
+
+		if (bytes_read == 0)
+			return 0;
+
+		// benski> checking bytes_read and node.size separately prevents possible integer overflow attack
+		if (bytes_read > size)
+			return 0;
+		total_bytes_read+=bytes_read;
+		size-=bytes_read;
+
+		if (node.size > size)
+			return 0;
+		total_bytes_read+=node.size;
+		size-=node.size;
+
+		switch(node.id)
+		{
+		case mkv_cues_cuepoint:
+			{
+#ifdef WA_VALIDATE
+				printf("  Cue Point\n");
+#endif
+				CuePoint *cue_point = new CuePoint;
+				if (ReadCuePoint(reader, node.size, *cue_point) == 0)
+				{
+					delete cue_point;
+					return 0;
+				}
+				cues.cue_points[cue_point->cue_time] = cue_point;				
+			}
+			break;
+		default:
+			ReadGlobal(reader, node.id, node.size);
+		}
+	}
+	return total_bytes_read;
+}
+