public ParsedContent Read(Stream stream)
{
var res = new ParsedContent();
var bodies = new List<Element>();
var info = new AtomCollection(Channel.ChannelInfo.Extra);
var processed = false;
var eos = false;
while (!eos) {
var start_pos = stream.Position;
try {
var elt = Element.ReadHeader(stream);
if (ebml.MaxIDLength <elt.ID.Length ||
ebml.MaxSizeLength<elt.Size.Length) {
throw new BadDataException();
}
switch (state) {
case ReaderState.EBML:
if (elt.ID.BinaryEquals(Elements.EBML)) {
elt.ReadBody(stream);
ebml = new EBML(elt);
state = ReaderState.Segment;
}
else {
throw new BadDataException();
}
break;
case ReaderState.Segment:
if (elt.ID.BinaryEquals(Elements.Segment)) {
segment = new Segment(elt);
state = ReaderState.EndOfHeader;
}
else if (elt.ID.BinaryEquals(Elements.EBML)) {
stream.Position = elt.Position;
state = ReaderState.EBML;
continue;
}
else if (elt.ID.BinaryEquals(Elements.Void) ||
elt.ID.BinaryEquals(Elements.CRC32)) {
elt.ReadBody(stream);
}
else {
throw new BadDataException();
}
break;
case ReaderState.EndOfHeader:
if (elt.ID.BinaryEquals(Elements.Segment)) {
stream.Position = elt.Position;
state = ReaderState.Segment;
continue;
}
else if (elt.ID.BinaryEquals(Elements.EBML)) {
stream.Position = elt.Position;
state = ReaderState.EBML;
continue;
}
else if (elt.ID.BinaryEquals(Elements.Cluster)) {
stream.Position = elt.Position;
state = ReaderState.Cluster;
clusters.Clear();
MemoryStream header;
using (header=new MemoryStream()) {
ebml.Element.Write(header);
segment.Element.Write(header);
foreach (var c in segment.HeaderElements) {
c.Write(header);
}
}
streamIndex = Channel.GenerateStreamID();
streamOrigin = DateTime.Now;
res.ContentHeader = new Content(streamIndex, TimeSpan.Zero, 0, header.ToArray());
if (ebml.DocType=="webm") {
info.SetChanInfoType("WEBM");
info.SetChanInfoStreamType("video/webm");
info.SetChanInfoStreamExt(".webm");
}
else {
info.SetChanInfoType("MKV");
info.SetChanInfoStreamType("video/x-matroska");
info.SetChanInfoStreamExt(".mkv");
}
res.ChannelInfo = new ChannelInfo(info);
}
else {
elt.ReadBody(stream);
segment.AddHeader(elt);
}
break;
case ReaderState.Cluster:
if (elt.ID.BinaryEquals(Elements.Segment)) {
stream.Position = elt.Position;
state = ReaderState.Segment;
continue;
}
else if (elt.ID.BinaryEquals(Elements.EBML)) {
stream.Position = elt.Position;
state = ReaderState.EBML;
continue;
}
else if (elt.ID.BinaryEquals(Elements.Cluster)) {
if (clusters.Count>0) {
var timespan = clusters.Sum(c => c.Timespan);
if (timespan>=30.0) {
var sz = clusters.Sum(c => c.Timespan>0 ? c.BlockSize : 0);
var kbps = (int)((sz*8/timespan+900) / 1000.0);
info.SetChanInfoBitrate(kbps);
res.ChannelInfo = new ChannelInfo(info);
while (clusters.Count>1) clusters.RemoveFirst();
}
}
var cluster = new Cluster(elt);
clusters.AddLast(cluster);
bodies.Add(elt);
state = ReaderState.Timecode;
}
else if (elt.ID.BinaryEquals(Elements.Void) ||
elt.ID.BinaryEquals(Elements.CRC32)) {
elt.ReadBody(stream);
bodies.Add(elt);
}
else {
throw new BadDataException();
}
break;
case ReaderState.Timecode:
if (elt.ID.BinaryEquals(Elements.Segment)) {
stream.Position = elt.Position;
state = ReaderState.Segment;
continue;
}
else if (elt.ID.BinaryEquals(Elements.EBML)) {
stream.Position = elt.Position;
state = ReaderState.EBML;
continue;
}
else if (elt.ID.BinaryEquals(Elements.Cluster)) {
stream.Position = elt.Position;
state = ReaderState.Cluster;
continue;
}
else if (elt.ID.BinaryEquals(Elements.Timecode)) {
elt.ReadBody(stream);
if (clusters.Last!=null) {
clusters.Last.Value.Timecode =
Element.ReadUInt(new MemoryStream(elt.Data), elt.Data.Length)*(segment.TimecodeScale/1000000000.0);
if (clusters.Count>1) {
clusters.Last.Previous.Value.Timespan = clusters.Last.Value.Timecode - clusters.Last.Previous.Value.Timecode;
}
}
bodies.Add(elt);
state = ReaderState.Block;
}
else if (elt.ID.BinaryEquals(Elements.SimpleBlock) ||
elt.ID.BinaryEquals(Elements.BlockGroup)) {
stream.Position = elt.Position;
state = ReaderState.Block;
continue;
}
else {
elt.ReadBody(stream);
bodies.Add(elt);
}
break;
case ReaderState.Block:
if (elt.ID.BinaryEquals(Elements.Segment)) {
stream.Position = elt.Position;
state = ReaderState.Segment;
continue;
}
else if (elt.ID.BinaryEquals(Elements.EBML)) {
stream.Position = elt.Position;
state = ReaderState.EBML;
continue;
}
else if (elt.ID.BinaryEquals(Elements.Cluster)) {
stream.Position = elt.Position;
state = ReaderState.Cluster;
continue;
}
else if ((elt.ID.BinaryEquals(Elements.SimpleBlock) ||
elt.ID.BinaryEquals(Elements.BlockGroup)) &&
(clusters.Last.Value.BlockID==null ||
elt.ID.BinaryEquals(clusters.Last.Value.BlockID))) {
elt.ReadBody(stream);
clusters.Last.Value.BlockSize += elt.Size.Value;
clusters.Last.Value.BlockID = elt.ID.Binary;
bodies.Add(elt);
}
else if (clusters.Last.Value.BlockID==null) {
elt.ReadBody(stream);
bodies.Add(elt);
}
else {
stream.Position = elt.Position;
state = ReaderState.Cluster;
continue;
}
break;
}
processed = true;
}
catch (EndOfStreamException) {
if (!processed) throw;
stream.Position = start_pos;
eos = true;
}
catch (BadDataException) {
stream.Position = start_pos+1;
}
}
if (res.ContentHeader!=null) {
position =
res.ContentHeader.Position +
res.ContentHeader.Data.Length;
}
if (bodies.Count>0) {
res.Contents = new List<Content>();
foreach (var body in bodies) {
MemoryStream s;
using (s=new MemoryStream()) {
body.Write(s);
}
var data = s.ToArray();
res.Contents.Add(new Content(streamIndex, DateTime.Now-streamOrigin, position, data));
position += data.Length;
}
}
return res;
}
public async Task ReadAsync(IContentSink sink, Stream stream, CancellationToken cancel_token)
{
var state = ReaderState.EBML;
var position = 0L;
var stream_index = -1;
var stream_origin = DateTime.Now;
var timecode_scale = 1000000.0;
var ebml = new EBML();
var clusters = new LinkedList<Cluster>();
var headers = new List<Element>();
var eos = false;
while (!eos) {
try {
var elt = await Element.ReadHeaderAsync(stream, cancel_token);
if (ebml.MaxIDLength <elt.ID.Length ||
ebml.MaxSizeLength<elt.Size.Length) {
throw new BadDataException();
}
parse_retry:
switch (state) {
case ReaderState.EBML:
if (elt.ID.BinaryEquals(Elements.EBML)) {
await elt.ReadBodyAsync(stream, cancel_token);
headers.Clear();
headers.Add(elt);
ebml = new EBML(elt);
state = ReaderState.Segment;
}
else {
throw new BadDataException();
}
break;
case ReaderState.Segment:
if (elt.ID.BinaryEquals(Elements.Segment)) {
headers.Add(elt);
state = ReaderState.EndOfHeader;
}
else if (elt.ID.BinaryEquals(Elements.EBML)) {
state = ReaderState.EBML;
goto parse_retry;
}
else if (elt.ID.BinaryEquals(Elements.Void) ||
elt.ID.BinaryEquals(Elements.CRC32)) {
await elt.ReadBodyAsync(stream, cancel_token);
headers.Add(elt);
}
else {
throw new BadDataException();
}
break;
case ReaderState.EndOfHeader:
if (elt.ID.BinaryEquals(Elements.Segment)) {
state = ReaderState.Segment;
goto parse_retry;
}
else if (elt.ID.BinaryEquals(Elements.EBML)) {
state = ReaderState.EBML;
goto parse_retry;
}
else if (elt.ID.BinaryEquals(Elements.Cluster)) {
clusters.Clear();
MemoryStream header;
using (header=new MemoryStream()) {
foreach (var c in headers) {
c.Write(header);
}
}
headers.Clear();
stream_index = Channel.GenerateStreamID();
stream_origin = DateTime.Now;
position = 0;
sink.OnContentHeader(
new Content(stream_index, TimeSpan.Zero, 0, header.ToArray())
);
position += header.ToArray().LongLength;
var info = new AtomCollection();
if (ebml.DocType=="webm") {
info.SetChanInfoType("WEBM");
info.SetChanInfoStreamType("video/webm");
info.SetChanInfoStreamExt(".webm");
}
else {
info.SetChanInfoType("MKV");
info.SetChanInfoStreamType("video/x-matroska");
info.SetChanInfoStreamExt(".mkv");
}
sink.OnChannelInfo(new ChannelInfo(info));
state = ReaderState.Cluster;
goto parse_retry;
}
else if (elt.ID.BinaryEquals(Elements.Info)) {
await elt.ReadBodyAsync(stream, cancel_token);
var s = new MemoryStream(elt.Data);
while (s.Position<s.Length) {
var child = Element.ReadHeader(s);
if (child.ID.BinaryEquals(Elements.TimecodeScale)) {
timecode_scale = Element.ReadUInt(s, child.Size.Value) * 1.0;
}
else {
child.ReadBody(s);
}
}
headers.Add(elt);
}
else {
await elt.ReadBodyAsync(stream, cancel_token);
headers.Add(elt);
}
break;
case ReaderState.Cluster:
if (elt.ID.BinaryEquals(Elements.Segment)) {
state = ReaderState.Segment;
goto parse_retry;
}
else if (elt.ID.BinaryEquals(Elements.EBML)) {
state = ReaderState.EBML;
goto parse_retry;
}
else if (elt.ID.BinaryEquals(Elements.Cluster)) {
if (clusters.Count>0) {
var timespan = clusters.Sum(c => c.Timespan);
if (timespan>=30.0) {
var sz = clusters.Sum(c => c.Timespan>0 ? c.BlockSize : 0);
var kbps = (int)((sz*8/timespan+900) / 1000.0);
var info = new AtomCollection();
info.SetChanInfoBitrate(kbps);
sink.OnChannelInfo(new ChannelInfo(info));
while (clusters.Count>1) clusters.RemoveFirst();
}
}
var cluster = new Cluster(elt);
clusters.AddLast(cluster);
sink.OnContent(
new Content(stream_index, DateTime.Now-stream_origin, position, elt.ToArray())
);
position += elt.ByteSize;
state = ReaderState.Timecode;
}
else if (elt.ID.BinaryEquals(Elements.Void) ||
elt.ID.BinaryEquals(Elements.CRC32)) {
await elt.ReadBodyAsync(stream, cancel_token);
sink.OnContent(
new Content(stream_index, DateTime.Now-stream_origin, position, elt.ToArray())
);
position += elt.ByteSize;
}
else {
throw new BadDataException();
}
break;
case ReaderState.Timecode:
if (elt.ID.BinaryEquals(Elements.Segment)) {
state = ReaderState.Segment;
goto parse_retry;
}
else if (elt.ID.BinaryEquals(Elements.EBML)) {
state = ReaderState.EBML;
goto parse_retry;
}
else if (elt.ID.BinaryEquals(Elements.Cluster)) {
state = ReaderState.Cluster;
goto parse_retry;
}
else if (elt.ID.BinaryEquals(Elements.SimpleBlock) ||
elt.ID.BinaryEquals(Elements.BlockGroup)) {
state = ReaderState.Block;
goto parse_retry;
}
else if (elt.ID.BinaryEquals(Elements.Timecode)) {
await elt.ReadBodyAsync(stream, cancel_token);
if (clusters.Last!=null) {
clusters.Last.Value.Timecode =
Element.ReadUInt(new MemoryStream(elt.Data), elt.Data.Length)*(timecode_scale/1000000000.0);
if (clusters.Count>1) {
clusters.Last.Previous.Value.Timespan = clusters.Last.Value.Timecode - clusters.Last.Previous.Value.Timecode;
}
}
sink.OnContent(
new Content(stream_index, DateTime.Now-stream_origin, position, elt.ToArray())
);
position += elt.ByteSize;
state = ReaderState.Block;
}
else {
await elt.ReadBodyAsync(stream, cancel_token);
sink.OnContent(
new Content(stream_index, DateTime.Now-stream_origin, position, elt.ToArray())
);
position += elt.ByteSize;
}
break;
case ReaderState.Block:
if (elt.ID.BinaryEquals(Elements.Segment)) {
state = ReaderState.Segment;
goto parse_retry;
}
else if (elt.ID.BinaryEquals(Elements.EBML)) {
state = ReaderState.EBML;
goto parse_retry;
}
else if (elt.ID.BinaryEquals(Elements.Cluster)) {
state = ReaderState.Cluster;
goto parse_retry;
}
else if ((elt.ID.BinaryEquals(Elements.SimpleBlock) ||
elt.ID.BinaryEquals(Elements.BlockGroup)) &&
(clusters.Last.Value.BlockID==null ||
elt.ID.BinaryEquals(clusters.Last.Value.BlockID))) {
await elt.ReadBodyAsync(stream, cancel_token);
clusters.Last.Value.BlockSize += elt.Size.Value;
clusters.Last.Value.BlockID = elt.ID.Binary;
sink.OnContent(
new Content(stream_index, DateTime.Now-stream_origin, position, elt.ToArray())
);
position += elt.ByteSize;
}
else if (clusters.Last.Value.BlockID==null) {
await elt.ReadBodyAsync(stream, cancel_token);
sink.OnContent(
new Content(stream_index, DateTime.Now-stream_origin, position, elt.ToArray())
);
position += elt.ByteSize;
}
else {
state = ReaderState.Cluster;
goto parse_retry;
}
break;
}
}
catch (EndOfStreamException) {
eos = true;
}
catch (BadDataException) {
}
}
}
