public NalUnitReader(IH264Reader reader, BitStreamDataReader dataReader, IH264State state)
{
_reader = reader;
_dataReader = dataReader;
_state = state;
_maxTrailingZeroByteLength = (uint)H264Detector.Configurable[H264Detector.ConfigurationKey.MaxTrailingZeroByteLength];
_maxReferenceHeaderRetriesPerFragment = (uint)H264Detector.Configurable[H264Detector.ConfigurationKey.MaxReferenceHeaderRetriesPerFragment];
}
private bool ParseLongLengthPrefixedNalUnit(IH264Reader reader, IResultNodeState resultState)
{
uint nalUnitLength = reader.GetUInt(NalUnitParser.Attribute.NalUnitLength);
long nalUnitEndPosition = (reader.Position + nalUnitLength);
if (nalUnitEndPosition > reader.Length)
{
return(false);
}
//Parse remainder with specific nalunitparser (NOTE: Is not a sub-object)
reader.ParseOneNalUnit(_nalUnitParser, resultState, nalUnitEndPosition);
return(reader.Position == nalUnitEndPosition);
}
public H264ResultTreeBuilder(BitStreamDataReader dataReader, IH264Reader reader, IH264State state, IScanContext scanContext, NalUnitStreamParser nalUnitStreamParser, ByteStreamParser byteStreamParser)
{
_falseHitReduction = (bool)H264Detector.Configurable[H264Detector.ConfigurationKey.FalseHitReduction];
_dataReader = dataReader;
_reader = reader;
_state = state;
_scanContext = scanContext;
_nalUnitStreamParser = nalUnitStreamParser;
_byteStreamParser = byteStreamParser;
Configurable <H264Detector.ConfigurationKey> configurable = H264Detector.Configurable;
_maxGapBetweenPpsAndSlice = (uint)configurable[H264Detector.ConfigurationKey.MaxGapBetweenPpsAndSlice];
_maxGapBetweenPpsAndSps = (uint)configurable[H264Detector.ConfigurationKey.MaxGapBetweenPpsAndSps];
_maxGapBetweenNalUnits = (uint)configurable[H264Detector.ConfigurationKey.MaxGapBetweenNalUnits];
}
public void Parse(IH264Reader reader, IResultNodeState resultState)
{
long bytesRemaining = (reader.Length - reader.Position);
if (bytesRemaining < 4)
{
resultState.Invalidate();
return;
}
long startPosition = reader.Position;
// Check whether a sequence parameter set and a picture parameter set are
// separated by exactly one byte in a NAL unit stream.
// This is the case for H.264 streams embedded in 3GPP files.
ulong nextFiveBytes = reader.PeekFiveBytes();
if ((_state.NalUnitType == NalUnitType.SequenceParameterSet) &&
!IsShortLengthPrefixedNalUnit((uint)(nextFiveBytes >> 16), bytesRemaining) &&
IsShortLengthPrefixedNalUnit((uint)(nextFiveBytes >> 8) & 0xffffff, (bytesRemaining - 1)))
{
// Skip the byte that is part of the 3GPP container
reader.Position++;
bytesRemaining--;
nextFiveBytes = reader.PeekFiveBytes();
}
if (IsShortLengthPrefixedNalUnit((uint)(nextFiveBytes >> 16), bytesRemaining))
{
if (ParseShortLengthPrefixedNalUnit(reader, resultState) && resultState.Valid)
{
return; // Successfully parse SPS or PPS NAL unit
}
resultState.Reset();
reader.Position = startPosition;
}
if (IsLongLengthPrefixedNalUnit(nextFiveBytes, bytesRemaining))
{
if (ParseLongLengthPrefixedNalUnit(reader, resultState))
{
return; // Successfully parse slice NAL unit
}
}
resultState.Invalidate();
}
public void Parse(IH264Reader reader, IResultNodeState resultState)
{
if (reader.Position == reader.Length)
{
resultState.Invalidate();
return;
}
long nalUnitEndPosition;
// Remove 'zero byte' and 'start code prefix' for the 'byte stream' format
if (reader.PeekUInt() == 0x00000001)
{
// TODO: hoort eigenlijk bij de StartCodePrefix - zie pg. 305 van ITU-T H.264 (03/2010)
reader.GetFixedByte(0x00, NalUnitParser.Attribute.ZeroByte);
}
reader.GetFixedThreeBytes(0x000001, NalUnitParser.Attribute.StartCodePrefix);
var windowStart = reader.Position;
if (reader.NextNalUnit()) //Forward till after next nalunit startcode
{
nalUnitEndPosition = reader.Position; //Position of next nalunit start
}
else
{
nalUnitEndPosition = reader.Length;
}
reader.Position = windowStart; //rewind
if (!resultState.Valid)
{
return;
}
//Parse remainder with specific nalunitparser (NOTE: Is not a sub-object)
reader.ParseOneNalUnit(_nalUnitParser, resultState, nalUnitEndPosition);
}
