private void DecodeTransponderData(byte[] section, int endOfSection, ref int pointer)
{
if (pointer + 6 > endOfSection)
{
throw new Exception(string.Format("NIT: corruption detected at transponder data, pointer = {0}, end of section = {1}", pointer, endOfSection));
}
bool isMpeg2Transport = ((section[pointer] & 0x80) == 0);
bool isVerticalRightPolarisation = ((section[pointer] & 0x40) != 0);
int transponderNumber = (section[pointer++] & 0x3f);
byte cdsReference = section[pointer++];
Log.Log.Debug("NIT: transponder data, is MPEG 2 transport = {0}, is vertical/right polarisation = {1}, transponder number = {2}, CDS reference = {3}",
isMpeg2Transport, isVerticalRightPolarisation, transponderNumber, cdsReference);
if (isMpeg2Transport)
{
byte mmsReference = section[pointer++];
int vctId = (section[pointer] << 8) + section[pointer + 1];
pointer += 2;
bool isRootTransponder = ((section[pointer++] & 0x80) != 0);
Log.Log.Debug("NIT: MPEG 2 transponder data, MMS reference = {0}, VCT ID = 0x{1:x}, is root transponder = {2}", mmsReference, vctId, isRootTransponder);
}
else
{
bool isWideBandwidthVideo = ((section[pointer] & 0x80) != 0);
WaveformStandard waveformStandard = (WaveformStandard)(section[pointer++] & 0x1f);
bool isWideBandwidthAudio = ((section[pointer] & 0x80) != 0);
bool isCompandedAudio = ((section[pointer] & 0x40) != 0);
MatrixMode matrixMode = (MatrixMode)((section[pointer] >> 4) & 0x03);
int subcarrier2Offset = 10 * (((section[pointer] & 0x0f) << 6) + (section[pointer + 1] >> 2)); // kHz
pointer++;
int subcarrier1Offset = 10 * (((section[pointer] & 0x03) << 8) + section[pointer + 1]);
pointer += 2;
Log.Log.Debug("NIT: non-MPEG 2 transponder data, is WB video = {0}, waveform standard = {1}, is WB audio = {2}, is companded audio = {3}, matrix mode = {4}, subcarrier 2 offset = {5} kHz, subcarrier 1 offset = {6} kHz",
isWideBandwidthVideo, waveformStandard, isWideBandwidthAudio, isCompandedAudio, matrixMode, subcarrier2Offset, subcarrier1Offset);
}
}
private void DecodeVirtualChannelMap(byte[] section, int endOfSection, ref int pointer, AtscTransmissionMedium transmissionMedium, int vctId)
{
// Virtual channel formats depend on transmission medium.
if (pointer + 7 > endOfSection)
{
throw new Exception(string.Format("S-VCT: corruption detected at virtual channel map, pointer = {0}, end of section = {1}", pointer, endOfSection));
}
bool freqSpecIncluded = ((section[pointer] & 0x80) != 0);
bool symbolRateIncluded = ((section[pointer] & 0x40) != 0);
bool descriptorsIncluded = ((section[pointer++] & 0x20) != 0);
bool splice = ((section[pointer++] & 0x80) != 0);
uint activationTime = 0;
for (byte b = 0; b < 4; b++)
{
activationTime = activationTime << 8;
activationTime = section[pointer++];
}
byte numberOfVcRecords = section[pointer++];
Log.Log.Debug("S-VCT: virtual channel map, transmission medium = {0}, freq. spec. included = {1}, symbol rate included = {2}, descriptors included = {3}, splice = {4}, activation time = {5}, number of VC records = {6}",
transmissionMedium, freqSpecIncluded, symbolRateIncluded, descriptorsIncluded, splice, activationTime, numberOfVcRecords);
for (byte i = 0; i < numberOfVcRecords; i++)
{
if (pointer + 9 > endOfSection)
{
throw new Exception(string.Format("S-VCT: detected number of virtual channel records {0} is invalid, pointer = {1}, end of section = {2}, loop = {3}", numberOfVcRecords, pointer, endOfSection, i));
}
int virtualChannelNumber = ((section[pointer] & 0x0f) << 8) + section[pointer + 1];
pointer += 2;
_channelDefinitions.Add(virtualChannelNumber);
bool applicationVirtualChannel = ((section[pointer] & 0x80) != 0);
int bitstreamSelect = ((section[pointer] & 0x40) >> 6); // broadcast reserved
int pathSelect = ((section[pointer] & 0x20) >> 5); // satellite, SMATV, broadcast reserved
TransportType transportType = (TransportType)((section[pointer] & 0x10) >> 4);
ChannelType channelType = (ChannelType)(section[pointer++] & 0x0f);
int sourceId = (section[pointer] << 8) + section[pointer + 1];
pointer += 2;
Log.Log.Debug("S-VCT: virtual channel number = {0}, application virtual channel = {1}, bitstream select = {2}, path select = {3}, transport type = {4}, channel type = {5}, source ID = 0x{6:x}",
virtualChannelNumber, applicationVirtualChannel, bitstreamSelect, pathSelect, transportType, channelType, sourceId);
if (channelType == ChannelType.NvodAccess)
{
int nvodChannelBase = ((section[pointer] & 0x0f) << 8) + section[pointer + 1];
pointer += 2;
if (transmissionMedium == AtscTransmissionMedium.Smatv)
{
pointer += 3;
}
else if (transmissionMedium != AtscTransmissionMedium.OverTheAir)
{
pointer += 2;
}
Log.Log.Debug("S-VCT: NVOD channel base = 0x{0:x}", nvodChannelBase);
}
else
{
switch (transmissionMedium)
{
case AtscTransmissionMedium.Satellite:
if (transportType == TransportType.Mpeg2)
{
byte satellite = section[pointer++];
int transponder = (section[pointer++] & 0x3f);
int programNumber = (section[pointer] << 8) + section[pointer + 1];
pointer += 2;
Log.Log.Debug("S-VCT: satellite = {0}, transponder = {1}, program number = 0x{2:x}", satellite, transponder, programNumber);
}
else
{
byte satellite = section[pointer++];
int transponder = (section[pointer++] & 0x3f);
pointer += 2;
Log.Log.Debug("S-VCT: satellite = {0}, transponder = {1}", satellite, transponder);
}
break;
case AtscTransmissionMedium.Smatv:
if (transportType == TransportType.Mpeg2)
{
byte cdsReference = section[pointer++];
int programNumber = (section[pointer] << 8) + section[pointer + 1];
pointer += 2;
byte mmsReference = section[pointer++];
pointer++;
Log.Log.Debug("S-VCT: CDS reference = {0}, program number = 0x{1:x}, MMS reference = {2}", cdsReference, programNumber, mmsReference);
}
else
{
byte cdsReference = section[pointer++];
bool scrambled = ((section[pointer] & 0x80) != 0);
VideoStandard videoStandard = (VideoStandard)(section[pointer++] & 0x0f);
bool isWideBandwidthVideo = ((section[pointer] & 0x80) != 0);
WaveformStandard waveformStandard = (WaveformStandard)(section[pointer++] & 0x1f);
bool isWideBandwidthAudio = ((section[pointer] & 0x80) != 0);
bool isCompandedAudio = ((section[pointer] & 0x40) != 0);
MatrixMode matrixMode = (MatrixMode)((section[pointer] >> 4) & 0x03);
int subcarrier2Offset = 10 * (((section[pointer] & 0x0f) << 6) + (section[pointer + 1] >> 2)); // kHz
pointer++;
int subcarrier1Offset = 10 * (((section[pointer] & 0x03) << 8) + section[pointer + 1]);
pointer += 2;
Log.Log.Debug("S-VCT: CDS reference = {0}, scrambled = {1}, video standard = {2}, is WB video = {3}, waveform standard = {4}, is WB audio = {5}, is companded audio = {6}, matrix mode = {7}, subcarrier 2 offset = {8} kHz, subcarrier 1 offset = {9} kHz",
cdsReference, scrambled, videoStandard, isWideBandwidthVideo, waveformStandard, isWideBandwidthAudio,
isCompandedAudio, matrixMode, subcarrier2Offset, subcarrier1Offset);
}
break;
case AtscTransmissionMedium.OverTheAir:
if (transportType == TransportType.Mpeg2)
{
int programNumber = (section[pointer] << 8) + section[pointer + 1];
pointer += 2;
Log.Log.Debug("S-VCT: program number = 0x{0:x}", programNumber);
}
else
{
bool scrambled = ((section[pointer] & 0x80) != 0);
VideoStandard videoStandard = (VideoStandard)(section[pointer++] & 0x0f);
pointer++;
Log.Log.Debug("S-VCT: scrambled = {0}, video standard = {1}", scrambled, videoStandard);
}
break;
case AtscTransmissionMedium.Cable:
case AtscTransmissionMedium.Mmds:
if (transportType == TransportType.Mpeg2)
{
byte cdsReference = section[pointer++];
int programNumber = (section[pointer] << 8) + section[pointer + 1];
pointer += 2;
byte mmsReference = section[pointer++];
Log.Log.Debug("S-VCT: CDS reference = {0}, program number = 0x{1:x}, MMS reference = {2}", cdsReference, programNumber, mmsReference);
if (OnChannelDetail != null)
{
OnChannelDetail(transmissionMedium, vctId, virtualChannelNumber, applicationVirtualChannel, bitstreamSelect,
pathSelect, channelType, sourceId, cdsReference, programNumber, mmsReference);
}
}
else
{
byte cdsReference = section[pointer++];
bool scrambled = ((section[pointer] & 0x80) != 0);
VideoStandard videoStandard = (VideoStandard)(section[pointer++] & 0x0f);
pointer += 2;
Log.Log.Debug("S-VCT: CDS reference = {0}, scrambled = {1}, video standard = {2}", cdsReference, scrambled, videoStandard);
}
break;
default:
throw new Exception(string.Format("S-VCT: unsupported transmission medium {0}", transmissionMedium));
}
}
if (freqSpecIncluded || transmissionMedium == AtscTransmissionMedium.OverTheAir)
{
int frequencyUnit = 10; // kHz
if ((section[pointer] & 0x80) != 0)
{
frequencyUnit = 125; // kHz
}
int carrierFrequency = frequencyUnit * (((section[pointer] & 0x7f) << 8) + section[pointer + 1]); // kHz
pointer += 2;
Log.Log.Debug("S-VCT: frequency, unit = {0} kHz, carrier = {1} kHz", frequencyUnit, carrierFrequency);
}
if (symbolRateIncluded && transmissionMedium != AtscTransmissionMedium.OverTheAir)
{
// s/s
int symbolRate = ((section[pointer] & 0x0f) << 24) + (section[pointer + 1] << 16) + (section[pointer + 2] << 8) + section[pointer + 3];
pointer += 4;
Log.Log.Debug("S-VCT: symbol rate = {0} s/s", symbolRate);
}
if (descriptorsIncluded)
{
if (pointer >= endOfSection)
{
throw new Exception(string.Format("S-VCT: invalid section length at virtual channel map descriptor count, pointer = {0}, end of section = {1}, loop = {2}", pointer, endOfSection, i));
}
byte descriptorCount = section[pointer++];
for (byte d = 0; d < descriptorCount; d++)
{
if (pointer + 2 > endOfSection)
{
throw new Exception(string.Format("S-VCT: detected virtual channel map descriptor count {0} is invalid, pointer = {1}, end of section = {2}, loop = {3}, inner loop = {4}", descriptorCount, pointer, endOfSection, i, d));
}
byte tag = section[pointer++];
byte length = section[pointer++];
Log.Log.Debug("S-VCT: virtual channel map descriptor, tag = 0x{0:x}, length = {1}", tag, length);
if (pointer + length > endOfSection)
{
throw new Exception(string.Format("S-VCT: invalid virtual channel map descriptor length {0}, pointer = {1}, end of section = {2}, loop = {3}, inner loop = {4}", length, pointer, endOfSection, i, d));
}
pointer += length;
}
}
}
}
