diff options
author | Robin Gareus <robin@gareus.org> | 2017-11-04 16:39:08 +0100 |
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committer | Robin Gareus <robin@gareus.org> | 2017-11-04 16:39:08 +0100 |
commit | 8366fbaa62eb35224a9b0f0cfda09680ebed5cf2 (patch) | |
tree | 9b18278a6f797552214c04ab605e7645813fe400 /libs/ardour/delayline.cc | |
parent | 06abdee652d69a22ad7573d2392148c6fbe6d968 (diff) |
Change Delayline to use power-of-two size and bitmasking
Diffstat (limited to 'libs/ardour/delayline.cc')
-rw-r--r-- | libs/ardour/delayline.cc | 35 |
1 files changed, 20 insertions, 15 deletions
diff --git a/libs/ardour/delayline.cc b/libs/ardour/delayline.cc index 72ea208126..3f17dd05e7 100644 --- a/libs/ardour/delayline.cc +++ b/libs/ardour/delayline.cc @@ -93,7 +93,7 @@ DelayLine::run (BufferSet& bufs, samplepos_t /* start_sample */, samplepos_t /* Sample* rb = (*bi).get (); write_to_rb (rb, i->data (), add); } - _woff = (_woff + add) % _bsiz; + _woff = (_woff + add) & _bsiz_mask; delay_diff += add; } } else { @@ -104,18 +104,18 @@ DelayLine::run (BufferSet& bufs, samplepos_t /* start_sample */, samplepos_t /* for (AudioDlyBuf::iterator i = _buf.begin(); i != _buf.end (); ++i) { Sample* rb = (*i).get (); for (uint32_t s = 0; s < fade_out_len; ++s) { - sampleoffset_t off = (_woff + _bsiz - s) % _bsiz; + sampleoffset_t off = (_woff + _bsiz - s) & _bsiz_mask; rb[off] *= s / (float) fade_out_len; } /* clear data in rb */ // TODO optimize this using memset for (uint32_t s = 0; s < -delay_diff; ++s) { - sampleoffset_t off = (_woff + _bsiz + s) % _bsiz; + sampleoffset_t off = (_woff + _bsiz + s) & _bsiz_mask; rb[off] = 0.f; } } - _woff = (_woff - delay_diff) % _bsiz; + _woff = (_woff - delay_diff) & _bsiz_mask; /* fade-in, directly apply to input buffer */ for (BufferSet::audio_iterator i = bufs.audio_begin (); i != bufs.audio_end (); ++i) { @@ -138,7 +138,7 @@ DelayLine::run (BufferSet& bufs, samplepos_t /* start_sample */, samplepos_t /* // TODO consider handling fade_out & fade_in separately // if fade_out_len < fade_in_len. for (uint32_t s = 0; s < xfade_len; ++s) { - sampleoffset_t off = (_roff + s) % _bsiz; + sampleoffset_t off = (_roff + s) & _bsiz_mask; const gain_t g = s / (float) xfade_len; src[s] *= g; src[s] += (1.f - g) * rb[off]; @@ -146,9 +146,9 @@ DelayLine::run (BufferSet& bufs, samplepos_t /* start_sample */, samplepos_t /* } #ifndef NDEBUG - sampleoffset_t check = (_roff + delay_diff) % _bsiz; + sampleoffset_t check = (_roff + delay_diff) & _bsiz_mask; #endif - _roff = (_woff + _bsiz - pending_delay) % _bsiz; + _roff = (_woff + _bsiz - pending_delay) & _bsiz_mask; #ifndef NDEBUG assert (_roff == check); #endif @@ -165,20 +165,20 @@ DelayLine::run (BufferSet& bufs, samplepos_t /* start_sample */, samplepos_t /* Sample* rb = (*i).get (); uint32_t s = 0; for (; s < fade_out_len; ++s) { - sampleoffset_t off = (_roff + s) % _bsiz; + sampleoffset_t off = (_roff + s) & _bsiz_mask; rb[off] *= 1. - (s / (float) fade_out_len); } for (; s < _delay; ++s) { - sampleoffset_t off = (_roff + s) % _bsiz; + sampleoffset_t off = (_roff + s) & _bsiz_mask; rb[off] = 0; } - assert (_woff == ((_roff + s) % _bsiz)); + assert (_woff == ((_roff + s) & _bsiz_mask)); } // TODO consider adding a fade-in to bufs } /* delay audio buffers */ - assert (_delay == ((_woff - _roff + _bsiz) % _bsiz)); + assert (_delay == ((_woff - _roff + _bsiz) & _bsiz_mask)); AudioDlyBuf::iterator bi = _buf.begin (); if (_delay == 0) { /* do nothing */ @@ -189,8 +189,8 @@ DelayLine::run (BufferSet& bufs, samplepos_t /* start_sample */, samplepos_t /* write_to_rb (rb, i->data (), n_samples); read_from_rb (rb, i->data (), n_samples); } - _roff = (_roff + n_samples) % _bsiz; - _woff = (_woff + n_samples) % _bsiz; + _roff = (_roff + n_samples) & _bsiz_mask; + _woff = (_woff + n_samples) & _bsiz_mask; } else { /* only write _delay samples to ringbuffer, memmove buffer */ samplecnt_t tail = n_samples - _delay; @@ -201,8 +201,8 @@ DelayLine::run (BufferSet& bufs, samplepos_t /* start_sample */, samplepos_t /* memmove (&src[_delay], src, tail * sizeof(Sample)); read_from_rb (rb, src, _delay); } - _roff = (_roff + _delay) % _bsiz; - _woff = (_woff + _delay) % _bsiz; + _roff = (_roff + _delay) & _bsiz_mask; + _woff = (_woff + _delay) & _bsiz_mask; } } else { /* set new delay for MIDI only */ @@ -319,6 +319,10 @@ DelayLine::allocate_pending_buffers (samplecnt_t signal_delay, ChanCount const& samplecnt_t rbs = signal_delay + 8192 + 1; rbs = std::max (_bsiz, rbs); + uint64_t power_of_two; + for (power_of_two = 1; 1 << power_of_two < rbs; ++power_of_two) {} + rbs = 1 << power_of_two; + if (cc.n_audio () == _buf.size () && _bsiz == rbs) { return; } @@ -356,6 +360,7 @@ DelayLine::allocate_pending_buffers (samplecnt_t signal_delay, ChanCount const& } } _bsiz = rbs; + _bsiz_mask = _bsiz - 1; _buf.swap (pending_buf); } |