// NewDetection
// Detects the maximum size of noise level in a silent sample file
public static long GetSilenceAmplitude(Stream assetStream, AudioLibPCMFormat audioPCMFormat)
{
CancelOperation = false;
//m_AudioAsset = RefAsset.AudioMediaData;
BinaryReader brRef = new BinaryReader(assetStream);
// creates counter of size equal to clip size
//long lSize = RefAsset.AudioMediaData.PCMFormat.Data.ConvertTimeToBytes(RefAsset.AudioMediaData.AudioDuration.AsLocalUnits);
long lSize = audioPCMFormat.AdjustByteToBlockAlignFrameSize(assetStream.Length);
// Block size of audio chunck which is least count of detection
int Block;
// determine the Block size
if (audioPCMFormat.SampleRate > 22500)
{
Block = 192;
}
else
{
Block = 96;
}
//set reading position after the header
long lLargest = 0;
long lBlockSum;
// adjust the lSize to avoid reading beyond file length
//lSize = ((lSize / Block) * Block) - 4;
// Experiment starts here
double BlockTime = 25;
double assetTimeInMS = audioPCMFormat.ConvertBytesToTime(assetStream.Length) / AudioLibPCMFormat.TIME_UNIT;
//Console.WriteLine("assetTimeInMS " + assetTimeInMS);
long Iterations = Convert.ToInt64(assetTimeInMS / BlockTime);
long SampleCount = Convert.ToInt64((int)audioPCMFormat.SampleRate / (1000 / BlockTime));
long lCurrentSum = 0;
long lSumPrev = 0;
for (long j = 0; j < Iterations - 1; j++)
{
// BlockSum is function to retrieve average amplitude in Block
//lCurrentSum = GetAverageSampleValue(brRef, SampleCount) ;
lCurrentSum = GetAvragePeakValue(assetStream, SampleCount, audioPCMFormat);
lBlockSum = Convert.ToInt64((lCurrentSum + lSumPrev) / 2);
lSumPrev = lCurrentSum;
if (lLargest < lBlockSum)
{
lLargest = lBlockSum;
}
if (CancelOperation)
{
break;
}
}
long SilVal = Convert.ToInt64(lLargest);
brRef.Close();
return(SilVal);
}
public static long RemoveSilenceFromEnd(Stream assetStream, AudioLibPCMFormat audioPCMFormat, long threshold, double GapLength, double before)
{
GapLength = audioPCMFormat.ConvertTimeToBytes((long)GapLength);
before = audioPCMFormat.ConvertTimeToBytes((long)before);
CancelOperation = false;
double assetTimeInMS = audioPCMFormat.ConvertBytesToTime(assetStream.Length) / AudioLibPCMFormat.TIME_UNIT;
GapLength = audioPCMFormat.AdjustByteToBlockAlignFrameSize((long)GapLength);
before = audioPCMFormat.AdjustByteToBlockAlignFrameSize((long)before);
long lSum = 0;
double detectedSilenceTime = 0;
// flags to indicate phrases and silence
bool boolPhraseDetected = false;
double BlockTime = 25; // milliseconds
long Iterations = Convert.ToInt64(assetTimeInMS / BlockTime);
long SampleCount = Convert.ToInt64(audioPCMFormat.SampleRate / (1000 / BlockTime));
double errorCompensatingCoefficient = GetErrorCompensatingConstant(SampleCount, audioPCMFormat);
long lCurrentSum = 0;
long lSumPrev = 0;
bool IsSilenceDetected = false;
long phraseMarkTimeForDeletingSilence = 0;
BinaryReader br = new BinaryReader(assetStream);
for (long j = 0; j < Iterations - 1; j++)
{
if (CancelOperation)
{
return(0);
}
// decodes audio chunck inside block
lCurrentSum = GetAvragePeakValue(assetStream, SampleCount, audioPCMFormat);
lSum = (lCurrentSum + lSumPrev) / 2;
lSumPrev = lCurrentSum;
if (lSum < threshold)
{
if (!IsSilenceDetected)
{
phraseMarkTimeForDeletingSilence = audioPCMFormat.ConvertBytesToTime(Convert.ToInt64(errorCompensatingCoefficient * (j)) * SampleCount * audioPCMFormat.BlockAlign) / AudioLibPCMFormat.TIME_UNIT;
IsSilenceDetected = true;
}
}
else
{
IsSilenceDetected = false;
phraseMarkTimeForDeletingSilence = 0;
}
}
br.Close();
if (phraseMarkTimeForDeletingSilence != 0)
{
boolPhraseDetected = true;
detectedSilenceTime = phraseMarkTimeForDeletingSilence + before;
}
long detectedPhraseTimingsInTimeUnits = 0;
if (boolPhraseDetected == false)
{
return(0);
}
else
{
detectedPhraseTimingsInTimeUnits = Convert.ToInt64(detectedSilenceTime * AudioLibPCMFormat.TIME_UNIT);
}
return(detectedPhraseTimingsInTimeUnits);
}
/// <summary>
/// Detects phrases of the asset for which stream is provided and returns timing list of detected phrases in local units
/// </summary>
/// <param name="assetStream"></param>
/// <param name="audioPCMFormat"></param>
/// <param name="threshold"></param>
/// <param name="GapLength"></param>
/// <param name="before"></param>
/// <returns></returns>
private static List <long> ApplyPhraseDetection(Stream assetStream, AudioLibPCMFormat audioPCMFormat, long threshold, double GapLength, double before)
{
CancelOperation = false;
//m_AudioAsset = ManagedAsset.AudioMediaData;
double assetTimeInMS = audioPCMFormat.ConvertBytesToTime(assetStream.Length) / AudioLibPCMFormat.TIME_UNIT;
GapLength = audioPCMFormat.AdjustByteToBlockAlignFrameSize((long)GapLength);
before = audioPCMFormat.AdjustByteToBlockAlignFrameSize((long)before);
int Block = 0;
// determine the Block size
if (audioPCMFormat.SampleRate > 22500)
{
Block = 192;
}
else
{
Block = 96;
}
// count chunck of silence which trigger phrase detection
long lCountSilGap = (long)(2 * GapLength) / Block; // multiplied by two because j counter is incremented by 2
long lSum = 0;
List <double> detectedPhraseTimingList = new List <double>();
long lCheck = 0;
// flags to indicate phrases and silence
bool boolPhraseDetected = false;
bool boolBeginPhraseDetected = false;
double BlockTime = 25; // milliseconds
double BeforePhraseInMS = audioPCMFormat.ConvertBytesToTime((long)before) / AudioLibPCMFormat.TIME_UNIT;
//Console.WriteLine ("before , silgap " + BeforePhraseInMS+" , " + GapLength ) ;
lCountSilGap = Convert.ToInt64((audioPCMFormat.ConvertBytesToTime((long)GapLength) / AudioLibPCMFormat.TIME_UNIT) / BlockTime);
long Iterations = Convert.ToInt64(assetTimeInMS / BlockTime);
long SampleCount = Convert.ToInt64(audioPCMFormat.SampleRate / (1000 / BlockTime));
double errorCompensatingCoefficient = GetErrorCompensatingConstant(SampleCount, audioPCMFormat);
long SpeechBlockCount = 0;
long lCurrentSum = 0;
long lSumPrev = 0;
BinaryReader br = new BinaryReader(assetStream);
bool PhraseNominated = false;
long SpeechChunkSize = 5;
long Counter = 0;
for (long j = 0; j < Iterations - 1; j++)
{
if (CancelOperation)
{
return(null);
}
// decodes audio chunck inside block
//lCurrentSum = GetAverageSampleValue(br, SampleCount);
lCurrentSum = GetAvragePeakValue(assetStream, SampleCount, audioPCMFormat);
lSum = (lCurrentSum + lSumPrev) / 2;
lSumPrev = lCurrentSum;
// conditional triggering of phrase detection
if (lSum < threshold)
{
lCheck++;
SpeechBlockCount = 0;
}
else
{
if (j < lCountSilGap && boolBeginPhraseDetected == false)
{
boolBeginPhraseDetected = true;
detectedPhraseTimingList.Add(Convert.ToInt64(0));
boolPhraseDetected = true;
lCheck = 0;
}
// checks the length of silence
if (lCheck > lCountSilGap)
{
PhraseNominated = true;
lCheck = 0;
}
if (PhraseNominated)
{
SpeechBlockCount++;
}
if (SpeechBlockCount >= SpeechChunkSize && Counter >= 4)
{
//sets the detection flag
boolPhraseDetected = true;
// changing following time calculations to reduce concatination of rounding off errors
//alPhrases.Add(((j - Counter) * BlockTime) - BeforePhraseInMS);
//double phraseMarkTime = ObiCalculationFunctions.ConvertByteToTime (Convert.ToInt64(errorCompensatingCoefficient * (j - Counter)) * SampleCount * m_AudioAsset.PCMFormat.Data.BlockAlign,
//(int) m_AudioAsset.PCMFormat.Data.SampleRate,
//(int) m_AudioAsset.PCMFormat.Data.BlockAlign);
long phraseMarkTime = audioPCMFormat.ConvertBytesToTime(Convert.ToInt64(errorCompensatingCoefficient * (j - Counter)) * SampleCount * audioPCMFormat.BlockAlign) / AudioLibPCMFormat.TIME_UNIT;
//Console.WriteLine("mark time :" + phraseMarkTime);
detectedPhraseTimingList.Add(phraseMarkTime - BeforePhraseInMS);
SpeechBlockCount = 0;
Counter = 0;
PhraseNominated = false;
}
lCheck = 0;
}
if (PhraseNominated)
{
Counter++;
}
// end outer For
}
br.Close();
List <long> detectedPhraseTimingsInTimeUnits = new List <long>();
if (boolPhraseDetected == false)
{
return(null);
}
else
{
for (int i = 0; i < detectedPhraseTimingList.Count; i++)
{
detectedPhraseTimingsInTimeUnits.Add(Convert.ToInt64(detectedPhraseTimingList[i] * AudioLibPCMFormat.TIME_UNIT));
}
}
return(detectedPhraseTimingsInTimeUnits);
}
public void PlayBytes(StreamProviderDelegate currentAudioStreamProvider,
long dataLength, AudioLibPCMFormat pcmInfo,
long bytesFrom, long bytesTo)
{
if (pcmInfo == null)
{
throw new ArgumentNullException("PCM format cannot be null !");
}
if (currentAudioStreamProvider == null)
{
throw new ArgumentNullException("Stream cannot be null !");
}
if (dataLength <= 0)
{
throw new ArgumentOutOfRangeException("Duration cannot be <= 0 !");
}
if (CurrentState == State.NotReady)
{
return;
}
if (CurrentState != State.Stopped)
{
Debug.Fail("Attempting to play when not stopped ? " + CurrentState);
return;
}
#if USE_SOUNDTOUCH
if (false && pcmInfo.NumberOfChannels > 1)
{
m_UseSoundTouch = false; //TODO: stereo all scrambled with SoundTouch !!
}
else
{
m_UseSoundTouch = m_UseSoundTouchBackup;
}
#endif // USE_SOUNDTOUCH
m_CurrentAudioStreamProvider = currentAudioStreamProvider;
m_CurrentAudioStream = m_CurrentAudioStreamProvider();
m_CurrentAudioPCMFormat = pcmInfo;
m_CurrentAudioDataLength = dataLength;
long startPosition = 0;
if (bytesFrom > 0)
{
startPosition = m_CurrentAudioPCMFormat.AdjustByteToBlockAlignFrameSize(bytesFrom);
}
long endPosition = 0;
if (bytesTo > 0)
{
endPosition = m_CurrentAudioPCMFormat.AdjustByteToBlockAlignFrameSize(bytesTo);
}
if (m_CurrentAudioPCMFormat.BytesAreEqualWithMillisecondsTolerance(startPosition, 0))
{
startPosition = 0;
}
if (m_CurrentAudioPCMFormat.BytesAreEqualWithMillisecondsTolerance(endPosition, dataLength))
{
endPosition = dataLength;
}
if (m_CurrentAudioPCMFormat.BytesAreEqualWithMillisecondsTolerance(endPosition, 0))
{
endPosition = 0;
}
if (endPosition != 0 &&
m_CurrentAudioPCMFormat.BytesAreEqualWithMillisecondsTolerance(endPosition, startPosition))
{
return;
}
if (startPosition >= 0 &&
(endPosition == 0 || startPosition < endPosition) &&
endPosition <= dataLength)
{
if (m_FwdRwdRate == 0)
{
startPlayback(startPosition, endPosition);
Console.WriteLine("starting playback ");
}
else if (m_FwdRwdRate > 0)
{
FastForward(startPosition);
Console.WriteLine("fast forward ");
}
else if (m_FwdRwdRate < 0)
{
if (startPosition == 0)
{
startPosition = m_CurrentAudioStream.Length;
}
Rewind(startPosition);
Console.WriteLine("Rewind ");
}
}
else
{
//throw new Exception("Start/end positions out of bounds of audio asset.");
DebugFix.Assert(false);
}
}
