audacia/src/PlaybackSchedule.cpp

296 lines
8.2 KiB
C++

/**********************************************************************
Audacity: A Digital Audio Editor
PlaybackSchedule.cpp
Paul Licameli split from AudioIOBase.cpp
**********************************************************************/
#include "PlaybackSchedule.h"
#include "AudioIOBase.h"
#include "Envelope.h"
void PlaybackSchedule::Init(
const double t0, const double t1,
const AudioIOStartStreamOptions &options,
const RecordingSchedule *pRecordingSchedule )
{
if ( pRecordingSchedule )
// It does not make sense to apply the time warp during overdub recording,
// which defeats the purpose of making the recording synchronized with
// the existing audio. (Unless we figured out the inverse warp of the
// captured samples in real time.)
// So just quietly ignore the time track.
mEnvelope = nullptr;
else
mEnvelope = options.envelope;
mT0 = t0;
if (pRecordingSchedule)
mT0 -= pRecordingSchedule->mPreRoll;
mT1 = t1;
if (pRecordingSchedule)
// adjust mT1 so that we don't give paComplete too soon to fill up the
// desired length of recording
mT1 -= pRecordingSchedule->mLatencyCorrection;
// Main thread's initialization of mTime
SetTrackTime( mT0 );
mPlayMode = options.playLooped
? PlaybackSchedule::PLAY_LOOPED
: PlaybackSchedule::PLAY_STRAIGHT;
mCutPreviewGapStart = options.cutPreviewGapStart;
mCutPreviewGapLen = options.cutPreviewGapLen;
#ifdef EXPERIMENTAL_SCRUBBING_SUPPORT
bool scrubbing = (options.pScrubbingOptions != nullptr);
// Scrubbing is not compatible with looping or recording or a time track!
if (scrubbing)
{
const auto &scrubOptions = *options.pScrubbingOptions;
if (pRecordingSchedule ||
Looping() ||
mEnvelope ||
scrubOptions.maxSpeed < ScrubbingOptions::MinAllowedScrubSpeed()) {
wxASSERT(false);
scrubbing = false;
}
else {
if (scrubOptions.isPlayingAtSpeed)
mPlayMode = PLAY_AT_SPEED;
else if (scrubOptions.isKeyboardScrubbing)
mPlayMode = PLAY_KEYBOARD_SCRUB;
else
mPlayMode = PLAY_SCRUB;
}
}
#endif
mWarpedTime = 0.0;
#ifdef EXPERIMENTAL_SCRUBBING_SUPPORT
if (Scrubbing())
mWarpedLength = 0.0f;
else
#endif
mWarpedLength = RealDuration(mT1);
}
double PlaybackSchedule::LimitTrackTime() const
{
// Track time readout for the main thread
// Allows for forward or backward play
return ClampTrackTime( GetTrackTime() );
}
double PlaybackSchedule::ClampTrackTime( double trackTime ) const
{
if (ReversedTime())
return std::max(mT1, std::min(mT0, trackTime));
else
return std::max(mT0, std::min(mT1, trackTime));
}
double PlaybackSchedule::NormalizeTrackTime() const
{
// Track time readout for the main thread
// dmazzoni: This function is needed for two reasons:
// One is for looped-play mode - this function makes sure that the
// position indicator keeps wrapping around. The other reason is
// more subtle - it's because PortAudio can query the hardware for
// the current stream time, and this query is not always accurate.
// Sometimes it's a little behind or ahead, and so this function
// makes sure that at least we clip it to the selection.
//
// msmeyer: There is also the possibility that we are using "cut preview"
// mode. In this case, we should jump over a defined "gap" in the
// audio.
double absoluteTime;
#ifdef EXPERIMENTAL_SCRUBBING_SUPPORT
// Limit the time between t0 and t1 if not scrubbing.
// Should the limiting be necessary in any play mode if there are no bugs?
if (Interactive())
absoluteTime = GetTrackTime();
else
#endif
absoluteTime = LimitTrackTime();
if (mCutPreviewGapLen > 0)
{
// msmeyer: We're in cut preview mode, so if we are on the right
// side of the gap, we jump over it.
if (absoluteTime > mCutPreviewGapStart)
absoluteTime += mCutPreviewGapLen;
}
return absoluteTime;
}
bool PlaybackSchedule::PassIsComplete() const
{
// Test mTime within the PortAudio callback
if (Scrubbing())
return false; // but may be true if playing at speed
return Overruns( GetTrackTime() );
}
bool PlaybackSchedule::Overruns( double trackTime ) const
{
return (ReversedTime() ? trackTime <= mT1 : trackTime >= mT1);
}
namespace
{
/** @brief Compute the duration (in seconds at playback) of the specified region of the track.
*
* Takes a region of the time track (specified by the unwarped time points in the project), and
* calculates how long it will actually take to play this region back, taking the time track's
* warping effects into account.
* @param t0 unwarped time to start calculation from
* @param t1 unwarped time to stop calculation at
* @return the warped duration in seconds
*/
double ComputeWarpedLength(const Envelope &env, double t0, double t1)
{
return env.IntegralOfInverse(t0, t1);
}
/** @brief Compute how much unwarped time must have elapsed if length seconds of warped time has
* elapsed
*
* @param t0 The unwarped time (seconds from project start) at which to start
* @param length How many seconds of warped time went past.
* @return The end point (in seconds from project start) as unwarped time
*/
double SolveWarpedLength(const Envelope &env, double t0, double length)
{
return env.SolveIntegralOfInverse(t0, length);
}
}
double PlaybackSchedule::AdvancedTrackTime(
double time, double realElapsed, double speed ) const
{
if (ReversedTime())
realElapsed *= -1.0;
// Defense against cases that might cause loops not to terminate
if ( fabs(mT0 - mT1) < 1e-9 )
return mT0;
if (mEnvelope) {
wxASSERT( speed == 1.0 );
double total=0.0;
bool foundTotal = false;
do {
auto oldTime = time;
if (foundTotal && fabs(realElapsed) > fabs(total))
// Avoid SolveWarpedLength
time = mT1;
else
time = SolveWarpedLength(*mEnvelope, time, realElapsed);
if (!Looping() || !Overruns( time ))
break;
// Bug1922: The part of the time track outside the loop should not
// influence the result
double delta;
if (foundTotal && oldTime == mT0)
// Avoid integrating again
delta = total;
else {
delta = ComputeWarpedLength(*mEnvelope, oldTime, mT1);
if (oldTime == mT0)
foundTotal = true, total = delta;
}
realElapsed -= delta;
time = mT0;
} while ( true );
}
else {
time += realElapsed * fabs(speed);
// Wrap to start if looping
if (Looping()) {
while ( Overruns( time ) ) {
// LL: This is not exactly right, but I'm at my wits end trying to
// figure it out. Feel free to fix it. :-)
// MB: it's much easier than you think, mTime isn't warped at all!
time -= mT1 - mT0;
}
}
}
return time;
}
void PlaybackSchedule::TrackTimeUpdate(double realElapsed)
{
// Update mTime within the PortAudio callback
if (Interactive())
return;
auto time = GetTrackTime();
auto newTime = AdvancedTrackTime( time, realElapsed, 1.0 );
SetTrackTime( newTime );
}
double PlaybackSchedule::RealDuration(double trackTime1) const
{
double duration;
if (mEnvelope)
duration = ComputeWarpedLength(*mEnvelope, mT0, trackTime1);
else
duration = trackTime1 - mT0;
return fabs(duration);
}
double PlaybackSchedule::RealTimeRemaining() const
{
return mWarpedLength - mWarpedTime;
}
void PlaybackSchedule::RealTimeAdvance( double increment )
{
mWarpedTime += increment;
}
void PlaybackSchedule::RealTimeInit( double trackTime )
{
if (Scrubbing())
mWarpedTime = 0.0;
else
mWarpedTime = RealDuration( trackTime );
}
void PlaybackSchedule::RealTimeRestart()
{
mWarpedTime = 0;
}
double RecordingSchedule::ToConsume() const
{
return mDuration - Consumed();
}
double RecordingSchedule::Consumed() const
{
return std::max( 0.0, mPosition + TotalCorrection() );
}
double RecordingSchedule::ToDiscard() const
{
return std::max(0.0, -( mPosition + TotalCorrection() ) );
}