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Update the implementation to make sense in a multi-clip environment.
Previously, a mix-and-rendered track always contained silence from time zero
until the time at which the first audio happened, as well as silence between
sections of rendered audio. Any audio before time zero was silently lost.
These changes mean that the single rendered clip now starts at the first sound in any of the tracks being mix-and-rendered and stops at the end of the last sound. This avoids a lot of unneccessary silence, and ensures that mix-and-rendering a single clip in a track leaves the clip the same length in the new, rendered, track. This is very useful.
These changes should also fix at least one bug in the case where a user-defined selection is being mix-and-rendered, although it is not currently possible to do this from the UI.
This commit is contained in:
richardash1981 2011-08-28 19:54:03 +00:00
parent 88c9e4720a
commit 819d13dc76
1 changed files with 40 additions and 15 deletions
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55
src/Mix.cpp
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@ -47,13 +47,7 @@ bool MixAndRender(TrackList *tracks, TrackFactory *trackFactory,
double startTime, double endTime,
WaveTrack **newLeft, WaveTrack **newRight)
{
// This function was formerly known as "Quick Mix". It takes one or
// more tracks as input; of all tracks that are selected, it mixes
// them together, applying any envelopes, amplitude gain, panning,
// and real-time effects in the process. The resulting pair of
// tracks (stereo) are "rendered" and have no effects, gain, panning,
// or envelopes.
// This function was formerly known as "Quick Mix".
WaveTrack **waveArray;
Track *t;
int numWaves = 0; /* number of wave tracks in the selection */
@ -79,22 +73,47 @@ bool MixAndRender(TrackList *tracks, TrackFactory *trackFactory,
if (numMono == numWaves)
mono = true;
double totalTime = 0.0;
/* the next loop will do two things at once:
* 1. build an array of all the wave tracks were are trying to process
* 2. determine when the set of WaveTracks starts and ends, in case we
* need to work out for ourselves when to start and stop rendering.
*/
double mixStartTime; /* start time of first track to start */
bool gotstart = false; // flag indicates we have found a start time
double mixEndTime = 0.0; /* end time of last track to end */
double tstart, tend; // start and end times for one track.
waveArray = new WaveTrack *[numWaves];
w = 0;
t = iter.First();
while (t) {
if (t->GetSelected() && t->GetKind() == Track::Wave) {
waveArray[w++] = (WaveTrack *) t;
if (t->GetEndTime() > totalTime)
totalTime = t->GetEndTime();
}
tstart = t->GetStartTime();
tend = t->GetEndTime();
if (tend > mixEndTime)
mixEndTime = tend;
// try and get the start time. If the track is empty we will get 0,
// which is ambiguous because it could just mean the track starts at
// the beginning of the project, as well as empty track. The give-away
// is that an empty track also ends at zero.
if (tstart != tend) {
// we don't get empty tracks here
if (!gotstart) {
// no previous start, use this one unconditionally
mixStartTime = tstart;
} else if (tstart < mixStartTime)
mixStartTime = tstart; // have a start, only make it smaller
} // end if start and end are different
} // end if track is a selected WaveTrack.
/** @TODO: could we not use a SelectedTrackListOfKindIterator here? */
t = iter.Next();
}
/* create the destination track (new track) */
if ((numWaves == 1) || ((numWaves == 2) && (iter.First()->GetLink() != NULL)))
oneinput = true;
// only one input track (either 1 mono or one linked stereo pair)
@ -104,6 +123,7 @@ bool MixAndRender(TrackList *tracks, TrackFactory *trackFactory,
mixLeft->SetName(iter.First()->GetName()); /* set name of output track to be the same as the sole input track */
else
mixLeft->SetName(_("Mix"));
mixLeft->SetOffset(mixStartTime);
WaveTrack *mixRight = 0;
if (mono) {
mixLeft->SetChannel(Track::MonoChannel);
@ -116,14 +136,19 @@ bool MixAndRender(TrackList *tracks, TrackFactory *trackFactory,
mixRight->SetName(_("Mix"));
mixLeft->SetChannel(Track::LeftChannel);
mixRight->SetChannel(Track::RightChannel);
mixRight->SetOffset(mixStartTime);
mixLeft->SetLinked(true);
}
int maxBlockLen = mixLeft->GetIdealBlockSize();
// If the caller didn't specify a time range, use the whole range in which
// any input track had clips in it.
if (startTime == endTime) {
startTime = 0.0;
endTime = totalTime;
startTime = mixStartTime;
endTime = mixEndTime;
}
Mixer *mixer = new Mixer(numWaves, waveArray, tracks->GetTimeTrack(),
@ -153,7 +178,7 @@ bool MixAndRender(TrackList *tracks, TrackFactory *trackFactory,
mixRight->Append(buffer, format, blockLen);
}
updateResult = progress->Update(mixer->MixGetCurrentTime(), totalTime);
updateResult = progress->Update(mixer->MixGetCurrentTime() - startTime, endTime - startTime);
}
delete progress;