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fix(es) from chris cannam for rb_effect mistakes

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git-svn-id: svn://localhost/ardour2/branches/2.0-ongoing@3424 d708f5d6-7413-0410-9779-e7cbd77b26cf
This commit is contained in:
Paul Davis 2008-05-29 14:45:13 +00:00
parent e1475964e5
commit 5fc24b7f01
2 changed files with 111 additions and 39 deletions
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138
libs/ardour/rb_effect.cc
View file

@ -74,37 +74,102 @@ RBEffect::run (boost::shared_ptr<AudioRegion> region)
nframes_t pos = 0;
int avail = 0;
// note: this_time_fraction is a ratio of original length. 1.0 = no change,
// 0.5 is half as long, 2.0 is twice as long, etc.
cerr << "RBEffect: source region: position = " << region->position()
<< ", start = " << region->start()
<< ", length = " << region->length()
<< ", ancestral_start = " << region->ancestral_start()
<< ", ancestral_length = " << region->ancestral_length()
<< ", stretch " << region->stretch()
<< ", shift " << region->shift() << endl;
double this_time_fraction = tsr.time_fraction * region->stretch ();
double this_pitch_fraction = tsr.pitch_fraction * region->shift ();
/*
We have two cases to consider:
1. The region has not been stretched before.
In this case, we just want to read region->length() frames
from region->start().
We will create a new region of region->length() *
tsr.time_fraction frames. The new region will have its
start set to 0 (because it has a new audio file that begins
at the start of the stretched area) and its ancestral_start
set to region->start() (so that we know where to begin
reading if we want to stretch it again).
2. The region has been stretched before.
The region starts at region->start() frames into its
(possibly previously stretched) source file. But we don't
want to read from its source file; we want to read from the
file it was originally stretched from.
The region's source begins at region->ancestral_start()
frames into its master source file. Thus, we need to start
reading at region->ancestral_start() + (region->start() /
region->stretch()) frames into the master source. This
value will also become the ancestral_start for the new
region.
We cannot use region->ancestral_length() to establish how
many frames to read, because it won't be up to date if the
region has been trimmed since it was last stretched. We
must read region->length() / region->stretch() frames and
stretch them by tsr.time_fraction * region->stretch(), for
a new region of region->length() * tsr.time_fraction
frames.
Case 1 is of course a special case of 2, where
region->ancestral_start() == 0 and region->stretch() == 1.
When we ask to read from a region, we supply a position on
the global timeline. The read function calculates the
offset into the source as (position - region->position()) +
region->start(). This calculation is used regardless of
whether we are reading from a master or
previously-stretched region. In order to read from a point
n frames into the master source, we need to provide n -
region->start() + region->position() as our position
argument to master_read_at().
Note that region->ancestral_length() is not used.
I hope this is clear.
*/
RubberBandStretcher stretcher (session.frame_rate(), region->n_channels(),
(RubberBandStretcher::Options) tsr.opts,
this_time_fraction, this_pitch_fraction);
double stretch = region->stretch() * tsr.time_fraction;
double shift = region->shift() * tsr.pitch_fraction;
nframes_t read_start = region->ancestral_start() +
nframes_t(region->start() / (double)region->stretch());
nframes_t read_duration =
nframes_t(region->length() / (double)region->stretch());
uint32_t channels = region->n_channels();
RubberBandStretcher stretcher
(session.frame_rate(), channels,
(RubberBandStretcher::Options) tsr.opts, stretch, shift);
tsr.progress = 0.0f;
tsr.done = false;
uint32_t channels = region->n_channels();
nframes_t duration = region->ancestral_length();
stretcher.setExpectedInputDuration(duration);
stretcher.setExpectedInputDuration(read_duration);
stretcher.setDebugLevel(1);
/* the name doesn't need to be super-precise, but allow for 2 fractional
digits just to disambiguate close but not identical FX
*/
if (this_time_fraction == 1.0) {
snprintf (suffix, sizeof (suffix), "@%d", (int) floor (this_pitch_fraction * 100.0f));
} else if (this_pitch_fraction == 1.0) {
snprintf (suffix, sizeof (suffix), "@%d", (int) floor (this_time_fraction * 100.0f));
if (stretch == 1.0) {
snprintf (suffix, sizeof (suffix), "@%d", (int) floor (shift * 100.0f));
} else if (shift == 1.0) {
snprintf (suffix, sizeof (suffix), "@%d", (int) floor (stretch * 100.0f));
} else {
snprintf (suffix, sizeof (suffix), "@%d-%d",
(int) floor (this_time_fraction * 100.0f),
(int) floor (this_pitch_fraction * 100.0f));
(int) floor (stretch * 100.0f),
(int) floor (shift * 100.0f));
}
/* create new sources */
@ -131,22 +196,26 @@ RBEffect::run (boost::shared_ptr<AudioRegion> region)
done = 0;
try {
while (pos < duration && !tsr.cancel) {
while (pos < read_duration && !tsr.cancel) {
nframes_t this_read = 0;
for (uint32_t i = 0; i < channels; ++i) {
this_read = 0;
nframes_t this_time;
this_time = min(bufsize, read_duration - pos);
this_time = min(bufsize, duration - pos);
nframes_t this_position;
this_position = read_start + pos -
region->start() + region->position();
this_read = region->master_read_at
(buffers[i],
buffers[i],
gain_buffer,
pos + region->position(),
this_position,
this_time,
i);
@ -161,15 +230,15 @@ RBEffect::run (boost::shared_ptr<AudioRegion> region)
pos += this_read;
done += this_read;
tsr.progress = ((float) done / duration) * 0.25;
tsr.progress = ((float) done / read_duration) * 0.25;
stretcher.study(buffers, this_read, pos == duration);
stretcher.study(buffers, this_read, pos == read_duration);
}
done = 0;
pos = 0;
while (pos < duration && !tsr.cancel) {
while (pos < read_duration && !tsr.cancel) {
nframes_t this_read = 0;
@ -177,14 +246,17 @@ RBEffect::run (boost::shared_ptr<AudioRegion> region)
this_read = 0;
nframes_t this_time;
this_time = min(bufsize, duration - pos);
this_time = min(bufsize, read_duration - pos);
nframes_t this_position;
this_position = read_start + pos -
region->start() + region->position();
this_read = region->master_read_at
(buffers[i],
buffers[i],
gain_buffer,
pos + region->position(),
this_position,
this_time,
i);
@ -199,9 +271,9 @@ RBEffect::run (boost::shared_ptr<AudioRegion> region)
pos += this_read;
done += this_read;
tsr.progress = 0.25 + ((float) done / duration) * 0.75;
tsr.progress = 0.25 + ((float) done / read_duration) * 0.75;
stretcher.process(buffers, this_read, pos == duration);
stretcher.process(buffers, this_read, pos == read_duration);
int avail = 0;
@ -261,10 +333,10 @@ RBEffect::run (boost::shared_ptr<AudioRegion> region)
for (vector<boost::shared_ptr<AudioRegion> >::iterator x = results.begin(); x != results.end(); ++x) {
(*x)->set_ancestral_data (region->ancestral_start(),
region->ancestral_length(),
this_time_fraction,
this_pitch_fraction );
(*x)->set_ancestral_data (read_start,
read_duration,
stretch,
shift);
(*x)->set_master_sources (region->get_master_sources());
}

12
libs/ardour/region.cc
View file

@ -95,10 +95,10 @@ Region::Region (boost::shared_ptr<const Region> other, nframes_t offset, nframes
}
_length = length;
_last_length = length;
_ancestral_start = other->_ancestral_start + offset;
_ancestral_length = length;
_stretch = 1.0;
_shift = 1.0;
_ancestral_start = other->_ancestral_start;
_ancestral_length = other->_ancestral_length;
_stretch = other->_stretch;
_shift = other->_shift;
_name = name;
_last_position = 0;
_position = 0;
@ -133,8 +133,8 @@ Region::Region (boost::shared_ptr<const Region> other)
_last_length = other->_length;
_ancestral_start = _start;
_ancestral_length = _length;
_stretch = 1.0;
_shift = 1.0;
_stretch = other->_stretch;
_shift = other->_shift;
_name = other->_name;
_last_position = other->_position;
_position = other->_position;