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#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;
}
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