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Fix issues when delay-buffers are re-allocated

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Previously buffers were dropped, and data was not copied to
newly allocated buffers. As side-effect the read-offset was not
adjusted either.

The distance between read and write-pointer needs to be maintained
(delay does not change). This needs to be accounted for, when the
buffer increases while read->write wraps around the old (smaller)
buffer. Previously this triggered an assert (in line 180)
This commit is contained in:
Robin Gareus 2019-09-29 16:10:51 +02:00
parent e3fc2614f7
commit cd5f70e69a
Signed by: rgareus
GPG Key ID: A090BCE02CF57F04
1 changed files with 16 additions and 7 deletions
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23
libs/ardour/delayline.cc
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@ -28,6 +28,8 @@
#include "ardour/midi_buffer.h"
#include "ardour/runtime_functions.h"
#define MAX_BUFFER_SIZE 8192
using namespace std;
using namespace PBD;
using namespace ARDOUR;
@ -62,6 +64,7 @@ DelayLine::run (BufferSet& bufs, samplepos_t /* start_sample */, samplepos_t /*
Glib::Threads::Mutex::Lock lm (_set_delay_mutex, Glib::Threads::TRY_LOCK);
assert (lm.locked ());
#endif
assert (n_samples <= MAX_BUFFER_SIZE);
const sampleoffset_t pending_delay = _pending_delay;
sampleoffset_t delay_diff = _delay - pending_delay;
@ -300,7 +303,7 @@ DelayLine::set_delay (samplecnt_t signal_delay)
string_compose ("%1 set_delay to %2 samples for %3 channels\n",
name (), signal_delay, _configured_output.n_audio ()));
if (signal_delay + 8192 + 1 > _bsiz) {
if (signal_delay + MAX_BUFFER_SIZE + 1 > _bsiz) {
allocate_pending_buffers (signal_delay, _configured_output);
}
@ -319,7 +322,8 @@ void
DelayLine::allocate_pending_buffers (samplecnt_t signal_delay, ChanCount const& cc)
{
assert (signal_delay >= 0);
samplecnt_t rbs = signal_delay + 8192 + 1;
assert (signal_delay >= _pending_delay);
samplecnt_t rbs = signal_delay + MAX_BUFFER_SIZE + 1;
rbs = std::max (_bsiz, rbs);
uint64_t power_of_two;
@ -330,7 +334,6 @@ DelayLine::allocate_pending_buffers (samplecnt_t signal_delay, ChanCount const&
return;
}
_buf.clear ();
if (cc.n_audio () == 0) {
return;
}
@ -345,23 +348,29 @@ DelayLine::allocate_pending_buffers (samplecnt_t signal_delay, ChanCount const&
AudioDlyBuf::iterator bo = _buf.begin ();
AudioDlyBuf::iterator bn = pending_buf.begin ();
sampleoffset_t offset = (_roff <= _woff) ? 0 : rbs - _bsiz;
for (; bo != _buf.end () && bn != pending_buf.end(); ++bo, ++bn) {
Sample* rbo = (*bo).get ();
Sample* rbn = (*bn).get ();
if (_roff < _woff) {
if (_roff == _woff) {
continue;
} else if (_roff < _woff) {
/* copy data between _roff .. _woff to new buffer */
copy_vector (&rbn[_roff], &rbo[_roff], _woff - _roff);
} else {
/* copy data between _roff .. old_size to end of new buffer, increment _roff
* copy data from 0.._woff to beginning of new buffer
*/
sampleoffset_t offset = rbs - _bsiz;
copy_vector (&rbn[_roff + offset], &rbo[_roff], _bsiz - _roff);
copy_vector (rbn, rbo, _woff);
_roff += offset;
assert (_roff < rbs);
}
}
assert ((_roff <= (_woff + signal_delay - _pending_delay) & (rbs -1)) || offset > 0);
_roff += offset;
assert (_roff < rbs);
_bsiz = rbs;
_bsiz_mask = _bsiz - 1;
_buf.swap (pending_buf);