|
public static ParseEbml ( Stream fs ) : |
||
| fs | Stream | |
| return | ||
public static EbmlElement ParseEbml(Stream fs)
{
Int64 pos = fs.Position;
EbmlElement ebml = null;
if (null == fs || fs.Length == 0)
return null;
int b = fs.ReadByte();
if (b == -1)
goto cleanup;
int len = VintLength((byte)b);
if ((fs.Length - fs.Position) < (Int64)len)
goto cleanup;
fs.Position -= 1;
Int64 id = 0;
for (int i = 0; i < len; i++)
{
id <<= 8;
id |= (byte)fs.ReadByte();
}
b = fs.ReadByte();
if (b == -1)
goto cleanup;
len = VintLength((byte)b);
if ((fs.Length - fs.Position) < (Int64)len)
goto cleanup;
fs.Position -= 1;
Int64 size = VintToInt64(fs);
if ((fs.Length - fs.Position) < size)
goto cleanup;
ebml = new EbmlElement(id, size, fs.Position, fs);
cleanup:
fs.Position = pos;
return ebml;
}
protected override void GetInitialValues()
{
fs.Seek(0, SeekOrigin.Begin);
UInt32 header = 0xffffffff;
EbmlElement mkv = null;
byte b = 0;
for (int i = 0; i < Constants.DISK_BUFFER; i++)
{
int ib = fs.ReadByte();
if (ib == -1)
{
throw new FormatException("The specified file is too short");
}
b = (byte)(ib & 0xff);
header <<= 8;
header |= b;
if (header == Constants.MKVSEGMENT_START)
{
fs.Seek(-4, SeekOrigin.Current);
mkv = EbmlElement.ParseEbml(fs);
if (null == mkv)
{
throw new FormatException("Invalid/Corrupted MKV file");
}
break;
}
}
EbmlElement[] clusts = mkv.Children;
foreach (EbmlElement clust in clusts)
{
ReportProgress((int)(50 * clust.DataStream.Position / clust.DataStream.Length));
if (clust.Id == Constants.MKVCLUSTER_START)
{
Clusters.Add(GetClusterClock(clust), clust);
}
else if (clust.Id == Constants.MKVTRACKINFO_START)
{
EbmlElement[] tracks = clust.Children;
ushort id = 0;
List <StreamInfo> mkvStreams = new List <StreamInfo>();
foreach (EbmlElement track in tracks)
{
if (track.Id == 0xae)
{
EbmlElement[] trackAttributes = track.Children;
string codec = null;
ushort pid = 0;
UInt64 uid = 0;
byte[] data = null;
EbmlElement elementaryInfo = null;
foreach (EbmlElement trackAtt in trackAttributes)
{
switch (trackAtt.Id)
{
case 0xd7: // Track number
for (Int64 i = 0; i < trackAtt.Size; i++)
{
pid <<= 8;
pid |= (byte)fs.ReadByte();
}
break;
case 0x86: // Codec ID
byte[] cid = new byte[(int)trackAtt.Size];
trackAtt.DataStream.Read(cid, 0, (int)trackAtt.Size);
codec = Encoding.ASCII.GetString(cid);
break;
case 0x63a2: // Coded Private
data = new byte[(int)trackAtt.Size];
trackAtt.DataStream.Read(data, 0, (int)trackAtt.Size);
break;
case 0x73c5: // Track UID
for (Int64 i = 0; i < trackAtt.Size; i++)
{
uid <<= 8;
uid |= (byte)fs.ReadByte();
}
break;
case 0xe0: // Video elementary stream info
elementaryInfo = trackAtt;
break;
case 0xe1: // Audio elementary stream info
elementaryInfo = trackAtt;
break;
}
}
if (codec == null || pid == 0)
{
throw new FormatException("Track info is invalid");
}
if (0 == string.Compare(codec, "V_MPEG2", true, CultureInfo.InvariantCulture) ||
0 == string.Compare(codec, "V_MPEG4/ISO/AVC", true, CultureInfo.InvariantCulture) ||
0 == string.Compare(codec, "V_MS/VFW/FOURCC", true, CultureInfo.InvariantCulture) ||
0 == string.Compare(codec, "A_AC3", true, CultureInfo.InvariantCulture) ||
0 == string.Compare(codec, "A_DTS", true, CultureInfo.InvariantCulture))
{
id++;
TrackInfo ti = new TrackInfo(id, codec, data, elementaryInfo);
TrackList.Add(id, ti);
StreamInfo si = null;
if (0 == string.Compare(codec, "V_MPEG2", true, CultureInfo.InvariantCulture))
{
si = new StreamInfo(ElementaryStreamTypes.VIDEO_STREAM_MPEG2, id);
}
else if (0 == string.Compare(codec, "V_MPEG4/ISO/AVC", true, CultureInfo.InvariantCulture))
{
si = new StreamInfo(ElementaryStreamTypes.VIDEO_STREAM_H264, id);
}
else if (0 == string.Compare(codec, "V_MS/VFW/FOURCC", true, CultureInfo.InvariantCulture))
{
si = new StreamInfo(ElementaryStreamTypes.VIDEO_STREAM_VC1, id);
}
else if (0 == string.Compare(codec, "A_AC3", true, CultureInfo.InvariantCulture))
{
si = new StreamInfo(ElementaryStreamTypes.AUDIO_STREAM_AC3, id);
}
else if (0 == string.Compare(codec, "A_DTS", true, CultureInfo.InvariantCulture))
{
si = new StreamInfo(ElementaryStreamTypes.AUDIO_STREAM_DTS, id);
}
mkvStreams.Add(si);
}
}
}
if (mkvStreams.Count > 0)
{
sis = mkvStreams.ToArray();
}
}
}
GetTimeStamps();
CurrentIndex = 0;
}