audacia/src/effects/SimpleMono.cpp
Paul Licameli 5e7d41ec07 Each .cpp/.mm file includes corresponding header before any other...
... except Audacity.h

This forces us to make each header contain all forward declarations or nested
headers that it requires, rather than depend on context.
2019-03-17 22:54:52 -04:00

129 lines
4.0 KiB
C++

/**********************************************************************
Audacity: A Digital Audio Editor
SimpleMono.cpp
Dominic Mazzoni
*******************************************************************//**
\class EffectSimpleMono
\brief An abstract Effect class that simplifies the implementation of a basic
monaural effect. Inherit from it if your effect just modifies
a single track in place and doesn't care how many samples
it gets at a time.
Your derived class only needs to implement
GetSymbol, GetEffectAction, and ProcessSimpleMono.
*//*******************************************************************/
#include "../Audacity.h"
#include "SimpleMono.h"
#include "../WaveTrack.h"
#include <math.h>
bool EffectSimpleMono::Process()
{
//Iterate over each track
this->CopyInputTracks(); // Set up mOutputTracks.
bool bGoodResult = true;
mCurTrackNum = 0;
for( auto pOutWaveTrack : mOutputTracks->Selected< WaveTrack >() )
{
//Get start and end times from track
double trackStart = pOutWaveTrack->GetStartTime();
double trackEnd = pOutWaveTrack->GetEndTime();
//Set the current bounds to whichever left marker is
//greater and whichever right marker is less:
mCurT0 = mT0 < trackStart? trackStart: mT0;
mCurT1 = mT1 > trackEnd? trackEnd: mT1;
// Process only if the right marker is to the right of the left marker
if (mCurT1 > mCurT0) {
//Transform the marker timepoints to samples
auto start = pOutWaveTrack->TimeToLongSamples(mCurT0);
auto end = pOutWaveTrack->TimeToLongSamples(mCurT1);
//Get the track rate and samples
mCurRate = pOutWaveTrack->GetRate();
mCurChannel = pOutWaveTrack->GetChannel();
//NewTrackSimpleMono() will returns true by default
//ProcessOne() processes a single track
if (!NewTrackSimpleMono() || !ProcessOne(pOutWaveTrack, start, end))
{
bGoodResult = false;
break;
}
}
mCurTrackNum++;
}
this->ReplaceProcessedTracks(bGoodResult);
return bGoodResult;
}
//ProcessOne() takes a track, transforms it to bunch of buffer-blocks,
//and executes ProcessSimpleMono on these blocks
bool EffectSimpleMono::ProcessOne(WaveTrack * track,
sampleCount start, sampleCount end)
{
//Get the length of the buffer (as double). len is
//used simple to calculate a progress meter, so it is easier
//to make it a double now than it is to do it later
auto len = (end - start).as_double();
//Initiate a processing buffer. This buffer will (most likely)
//be shorter than the length of the track being processed.
Floats buffer{ track->GetMaxBlockSize() };
//Go through the track one buffer at a time. s counts which
//sample the current buffer starts at.
auto s = start;
while (s < end) {
//Get a block of samples (smaller than the size of the buffer)
//Adjust the block size if it is the final block in the track
const auto block =
limitSampleBufferSize( track->GetBestBlockSize(s), end - s );
//Get the samples from the track and put them in the buffer
track->Get((samplePtr) buffer.get(), floatSample, s, block);
//Process the buffer. If it fails, clean up and exit.
if (!ProcessSimpleMono(buffer.get(), block))
//Return false because the effect failed.
return false;
//Processing succeeded. copy the newly-changed samples back
//onto the track.
track->Set((samplePtr) buffer.get(), floatSample, s, block);
//Increment s one blockfull of samples
s += block;
//Update the Progress meter
if (TrackProgress(mCurTrackNum,
(s - start).as_double() /
len))
return false;
}
//Return true because the effect processing succeeded.
return true;
}
//null implementation of NewTrackSimpleMono
bool EffectSimpleMono::NewTrackSimpleMono()
{
return true;
}