C++ WaveTrack::GetBestBlockSize方法代码示例

//This might continue over a number of blocks.
double VoiceKey::TestEnergy (WaveTrack & t, sampleCount start, sampleCount len)
{

   double sum = 1;
   auto s = start;                                //Keep track of start
   auto originalLen = len;                        //Keep track of the length of block to process (its not the length of t)
   const auto blockSize = limitSampleBufferSize(
      t.GetMaxBlockSize(), len);               //Determine size of sampling buffer
   float *buffer = new float[blockSize];       //Get a sampling buffer

   while(len > 0)
      {
         //Figure out how much to grab
         auto block = limitSampleBufferSize ( t.GetBestBlockSize(s), len );

         t.Get((samplePtr)buffer,floatSample, s,block);                      //grab the block;

         //Now, go through the block and calculate energy
         for(decltype(block) i = 0; i< block; i++)
            {
               sum += buffer[i]*buffer[i];
            }

         len -= block;
         s += block;
      }

   delete [] buffer;
   return sum / originalLen.as_double();
}

bool EffectNoise::Process()
{
   if (noiseDuration <= 0.0)
      noiseDuration = sDefaultGenerateLen;

   //Iterate over each track
   TrackListIterator iter(mWaveTracks);
   WaveTrack *track = (WaveTrack *)iter.First();
   while (track) {
      WaveTrack *tmp = mFactory->NewWaveTrack(track->GetSampleFormat(), track->GetRate());
      numSamples = (longSampleCount)(noiseDuration * track->GetRate() + 0.5);
      longSampleCount i = 0;
      float *data = new float[tmp->GetMaxBlockSize()];
      sampleCount block;

      while(i < numSamples) {
         block = tmp->GetBestBlockSize(i);
         if (block > (numSamples - i))
             block = numSamples - i;

         MakeNoise(data, block, track->GetRate(), noiseAmplitude);

         tmp->Append((samplePtr)data, floatSample, block);
         i += block;
      }
      delete[] data;

      tmp->Flush();
      track->Clear(mT0, mT1);
      track->Paste(mT0, tmp);
      delete tmp;

      //Iterate to the next track
      track = (WaveTrack *)iter.Next();
   }

   /*
      save last used values
      save duration unless value was got from selection, so we save only
      when user explicitely setup a value
   */
   if (mT1 == mT0)
      gPrefs->Write(wxT("/CsPresets/NoiseGen_Duration"), noiseDuration);

   gPrefs->Write(wxT("/CsPresets/NoiseGen_Type"), noiseType);
   gPrefs->Write(wxT("/CsPresets/NoiseGen_Amp"), noiseAmplitude);

   mT1 = mT0 + noiseDuration; // Update selection.

   return true;
}

double VoiceKey::TestDirectionChanges(
   const WaveTrack & t, sampleCount start, sampleCount len)
{


   auto s = start;                                //Keep track of start
   auto originalLen = len;                        //Keep track of the length of block to process (its not the length of t)
   const auto blockSize = limitSampleBufferSize(
      t.GetMaxBlockSize(), len);               //Determine size of sampling buffer
   unsigned long directionchanges = 1;
   float lastval=float(0);
   int lastdirection=1;

   Floats buffer{ blockSize };       //Get a sampling buffer

   while(len > 0) {
      //Figure out how much to grab
      auto block = limitSampleBufferSize ( t.GetBestBlockSize(s), len );

      t.Get((samplePtr)buffer.get(), floatSample, s, block);                      //grab the block;

      if  (len == originalLen) {
         //The first time through, set stuff up special.
         lastval = buffer[0];
      }

      //Now, go through the block and calculate zero crossings


      for(decltype(block) i = 0; i< block; i++){

         if( sgn(buffer[i]-lastval) != lastdirection) {
            directionchanges++;
            lastdirection = sgn(buffer[i] - lastval);
         }
         lastval = buffer[i];

      }
      len -= block;
      s += block;
   }
   return (double)directionchanges/originalLen.as_double();
}

double VoiceKey::TestSignChanges(WaveTrack & t, sampleCount start, sampleCount len)
{


   auto s = start;                                //Keep track of start
   auto originalLen = len;                        //Keep track of the length of block to process (its not the length of t)
   const auto blockSize = limitSampleBufferSize(
      t.GetMaxBlockSize(), len);               //Determine size of sampling buffer
   unsigned long signchanges = 1;
   int currentsign=0;

   float *buffer = new float[blockSize];       //Get a sampling buffer

   while(len > 0) {
      //Figure out how much to grab
      auto block = limitSampleBufferSize ( t.GetBestBlockSize(s), len );

      t.Get((samplePtr)buffer,floatSample, s,block);                      //grab the block;

      if  (len == originalLen)
         {
            //The first time through, set stuff up special.
            currentsign = sgn(buffer[0]);
         }

      //Now, go through the block and calculate zero crossings

      for(decltype(block) i = 0; i< block; i++)
         {
            if( sgn(buffer[i]) != currentsign)
               {
                  currentsign = sgn(buffer[i]);
                  signchanges++;
               }

         }
      len -= block;
      s += block;
   }
   delete [] buffer;
   return (double)signchanges / originalLen.as_double();
}

bool EffectToneGen::Process()
{
   if (length <= 0.0)
      length = sDefaultGenerateLen;

   //Iterate over each track
   TrackListIterator iter(mWaveTracks);
   WaveTrack *track = (WaveTrack *)iter.First();
   while (track) {
      mSample = 0;
      WaveTrack *tmp = mFactory->NewWaveTrack(track->GetSampleFormat());
      mCurRate = track->GetRate();
      tmp->SetRate(mCurRate);
      longSampleCount numSamples =
         (longSampleCount)(length * mCurRate + 0.5);
      longSampleCount i = 0;
      float *data = new float[tmp->GetMaxBlockSize()];
      sampleCount block;

      while(i < numSamples) {
         block = tmp->GetBestBlockSize(i);
         if (block > (numSamples - i))
             block = numSamples - i;
         MakeTone(data, block);
         tmp->Append((samplePtr)data, floatSample, block);
         i += block;
      }
      delete[] data;

      tmp->Flush();
      track->Clear(mT0, mT1);
      track->Paste(mT0, tmp);
      delete tmp;
      
      //Iterate to the next track
      track = (WaveTrack *)iter.Next();
   }

	mT1 = mT0 + length; // Update selection.

   return true;
}

bool EffectNoise::Process()
{
   if (noiseDuration <= 0.0)
      noiseDuration = sDefaultGenerateLen;

   //Iterate over each track
   int ntrack = 0;
   this->CopyInputWaveTracks(); // Set up mOutputWaveTracks.
   bool bGoodResult = true;

   TrackListIterator iter(mOutputWaveTracks);
   WaveTrack *track = (WaveTrack *)iter.First();
   while (track) {
      WaveTrack *tmp = mFactory->NewWaveTrack(track->GetSampleFormat(), track->GetRate());
      numSamples = (longSampleCount)(noiseDuration * track->GetRate() + 0.5);
      longSampleCount i = 0;
      float *data = new float[tmp->GetMaxBlockSize()];
      sampleCount block;

      while ((i < numSamples) && bGoodResult) {
         block = tmp->GetBestBlockSize(i);
         if (block > (numSamples - i))
             block = numSamples - i;

         MakeNoise(data, block, track->GetRate(), noiseAmplitude);

         tmp->Append((samplePtr)data, floatSample, block);
         i += block;

         //Update the Progress meter
         if (TrackProgress(ntrack, (double)i / numSamples))
            bGoodResult = false;
      }
      delete[] data;

      tmp->Flush();
      track->Clear(mT0, mT1);
      track->Paste(mT0, tmp);
      delete tmp;

      if (!bGoodResult)
         break;

      //Iterate to the next track
      ntrack++;
      track = (WaveTrack *)iter.Next();
   }

   if (bGoodResult)
   {
      /*
         save last used values
         save duration unless value was got from selection, so we save only
         when user explicitely setup a value
      */
      if (mT1 == mT0)
         gPrefs->Write(wxT("/CsPresets/NoiseGen_Duration"), noiseDuration);

      gPrefs->Write(wxT("/CsPresets/NoiseGen_Type"), noiseType);
      gPrefs->Write(wxT("/CsPresets/NoiseGen_Amp"), noiseAmplitude);

      mT1 = mT0 + noiseDuration; // Update selection.
   }

   this->ReplaceProcessedWaveTracks(bGoodResult); 
   return bGoodResult;
}

bool EffectDtmf::Process()
{
   if (dtmfDuration <= 0.0)
      return false;

   //Iterate over each track
   TrackListIterator iter(mWaveTracks);
   WaveTrack *track = (WaveTrack *)iter.First();
   while (track) {
      // new tmp track, to fill with dtmf sequence
      // we will build the track by adding a tone, then a silence, next tone, and so on...
      WaveTrack *tmp = mFactory->NewWaveTrack(track->GetSampleFormat(), track->GetRate());

      // all dtmf sequence durations in samples from seconds
      numSamplesSequence = (longSampleCount)(dtmfDuration * track->GetRate() + 0.5);
      numSamplesTone = (longSampleCount)(dtmfTone * track->GetRate() + 0.5);
      numSamplesSilence = (longSampleCount)(dtmfSilence * track->GetRate() + 0.5);

      // recalculate the sum, and spread the difference - due to approximations.
      // Since diff should be in the order of "some" samples, a division (resulting in zero)
      // is not sufficient, so we add the additional remaining samples in each tone/silence block,
      // at least until available.
      int diff = numSamplesSequence - (dtmfNTones*numSamplesTone) - (dtmfNTones-1)*numSamplesSilence;
      if (diff>dtmfNTones) {
         // in this case, both these values would change, so it makes sense to recalculate diff
         // otherwise just keep the value we already have

         // should always be the case that dtmfNTones>1, as if 0, we don't even start processing,
         // and with 1 there is no difference to spread (no silence slot)...
         wxASSERT(dtmfNTones > 1);
         numSamplesTone += (diff/(dtmfNTones));
         numSamplesSilence += (diff/(dtmfNTones-1));
         diff = numSamplesSequence - (dtmfNTones*numSamplesTone) - (dtmfNTones-1)*numSamplesSilence;
      }
      // this var will be used as extra samples distributor
      int extra=0;

      longSampleCount i = 0;
      longSampleCount j = 0;
      int n=0; // pointer to string in dtmfString
      sampleCount block;
      bool isTone = true;
      float *data = new float[tmp->GetMaxBlockSize()];

      // for the whole dtmf sequence, we will be generating either tone or silence
      // according to a bool value, and this might be done in small chunks of size
      // 'block', as a single tone might sometimes be larger than the block
      // tone and silence generally have different duration, thus two generation blocks
      //
      // Note: to overcome a 'clicking' noise introduced by the abrupt transition from/to
      // silence, I added a fade in/out of 1/250th of a second (4ms). This can still be
      // tweaked but gives excellent results at 44.1kHz: I haven't tried other freqs.
      // A problem might be if the tone duration is very short (<10ms)... (?)
      //
      // One more problem is to deal with the approximations done when calculating the duration 
      // of both tone and silence: in some cases the final sum might not be same as the initial
      // duration. So, to overcome this, we had a redistribution block up, and now we will spread
      // the remaining samples in every bin in order to achieve the full duration: test case was
      // to generate an 11 tone DTMF sequence, in 4 seconds, and with DutyCycle=75%: after generation
      // you ended up with 3.999s or in other units: 3 seconds and 44097 samples.
      //
      while(i < numSamplesSequence) {
         if (isTone)
         // generate tone
         {
            // the statement takes care of extracting one sample from the diff bin and
            // adding it into the tone block until depletion
            extra=(diff-- > 0?1:0);
            for(j=0; j < numSamplesTone+extra; j+=block) {
               block = tmp->GetBestBlockSize(j);
               if (block > (numSamplesTone+extra - j))
                   block = numSamplesTone+extra - j;

               // generate the tone and append
               MakeDtmfTone(data, block, track->GetRate(), dtmfString[n], j, numSamplesTone);
               tmp->Append((samplePtr)data, floatSample, block);
            }
            i += numSamplesTone;
            n++;
            if(n>=dtmfNTones)break;
         }
         else
         // generate silence
         {
            // the statement takes care of extracting one sample from the diff bin and
            // adding it into the silence block until depletion
            extra=(diff-- > 0?1:0);
            for(j=0; j < numSamplesSilence+extra; j+=block) {
               block = tmp->GetBestBlockSize(j);
               if (block > (numSamplesSilence+extra - j))
                   block = numSamplesSilence+extra - j;

               // generate silence and append
               memset(data, 0, sizeof(float)*block);
               tmp->Append((samplePtr)data, floatSample, block);
            }
            i += numSamplesSilence;
         }
         // flip flag
         isTone=!isTone;
//.........这里部分代码省略.........