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#include "MKVInfo.h"
#include "../nsmkv/global_elements.h"
#include "../nsmkv/read.h"
#include "../nsmkv/segment.h"
#include "../nsmkv/tracks.h"
#include "../nsmkv/file_mkv_reader.h"
MKVInfo::MKVInfo()
{
segment_info_found = false;
content_length = 0;
tracks_found = false;
}
bool MKVInfo::Open(const wchar_t *filename)
{
FILE *f = _wfopen(filename, L"rb");
if (!f)
return false;
MKVReaderFILE reader(f);
content_length = reader.GetContentLength();
ebml_node node;
while (!segment_info_found)
{
if (read_ebml_node(&reader, &node) == 0)
break;
switch(node.id)
{
case mkv_header:
if (nsmkv::ReadHeader(&reader, node.size, header) == 0)
{
return false;
}
break;
case mkv_segment:
if (ReadSegment(&reader, node.size) == 0)
{
return false;
}
break;
default:
nsmkv::SkipNode(&reader, node.id, node.size);
}
}
return segment_info_found;
}
uint64_t MKVInfo::ReadSegment(nsmkv::MKVReader *reader, uint64_t size)
{
uint64_t total_bytes_read=0;
while (size && (!segment_info_found || !tracks_found))
{
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_segment_segmentinfo:
{
if (ReadSegmentInfo(reader, node.size, segment_info) == 0)
return 0;
segment_info_found=true;
}
break;
case mkv_segment_tracks:
{
if (ReadTracks(reader, node.size, tracks) == 0)
return 0;
tracks_found=true;
}
break;
default:
if (nsmkv::SkipNode(reader, node.id, node.size) == 0)
return 0;
}
}
return total_bytes_read;
}
int MKVInfo::GetLengthMilliseconds()
{
if (!segment_info_found)
return -1000;
else
return segment_info.GetDurationMilliseconds();
}
const char *MKVInfo::GetTitle()
{
return segment_info.title;
}
int MKVInfo::GetBitrate()
{
if (segment_info_found)
{
int time_ms = segment_info.GetDurationMilliseconds();
if (time_ms)
return (int) (8ULL * content_length / (uint64_t)time_ms);
}
return 0;
}
bool MKVInfo::GetHeight(int &height)
{
if (tracks_found)
{
size_t i=0;
const nsmkv::TrackEntry *track=0;
while (track = tracks.EnumTrack(i++))
{
if (track->track_type == mkv_track_type_video)
{
height = (int)track->video.pixel_height;
return true;
}
}
}
return false;
}
bool MKVInfo::GetWidth(int &width)
{
if (tracks_found)
{
size_t i=0;
const nsmkv::TrackEntry *track=0;
while (track = tracks.EnumTrack(i++))
{
if (track->track_type == mkv_track_type_video)
{
width = (int)track->video.pixel_width;
return true;
}
}
}
return false;
}
const nsmkv::Tracks *MKVInfo::GetTracks()
{
if (tracks_found)
return &tracks;
else
return 0;
}
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