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/*
* Copyright (C) 2016 Robin Gareus <robin@gareus.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#ifndef __ardour_fixed_delay_h__
#define __ardour_fixed_delay_h__
#include <vector>
#include "ardour/buffer.h"
namespace ARDOUR {
class ChanCount;
/** Multichannel Audio/Midi Delay Line
*
* This is an efficient delay line operating directly on Ardour buffers.
* The drawback is that there is no thread safety:
* All calls need to be executed in the same thread.
*
* After configuration, the delay can be changed safely up to the maximum
* configured delay but doing so flushes the buffer. There is no de-clicking
* (see ARDOUR::Delayline for those cases).
*
* Increasing the delay above the max configured or requesting more
* buffers will allocate the required space (not realtime safe).
*
* All buffers part of the set are treated separately.
*/
class LIBARDOUR_API FixedDelay
{
public:
FixedDelay ();
~FixedDelay ();
/** initial configuration, usually done after instantiation
*
* @param count Channel Count (audio+midi)
* @param max_delay the maximum number of samples to delay
* @param shrink when false already allocated buffers are kept if both channel-count and max-delay requirements are satisified
*/
void configure (const ChanCount& count, framecnt_t max_delay, bool shrink = true);
/** set delay time and update active process buffers
*
* This calls configure with shrink = false and sets the current delay time
* if the delay time mismatches, the buffers are silenced (zeroed).
*
* @param count channels to be processed
* @param delay number of audio samples to delay
*/
void set (const ChanCount& count, framecnt_t delay);
/** process a channel
*
* Read N samples from the input buffer, delay them by the configured delay-time and write
* the delayed samples to the output buffer at the given offset.
*
* @param dt datatype
* @param id buffer number (starting at 0)
* @param out output buffer to write data to
* @param in input buffer to read data from
* @param n_samples number of samples to process (must be <= 8192)
* @param dst_offset offset in output buffer to start writing to
* @param src_offset offset in input buffer to start reading from
*/
void delay (ARDOUR::DataType dt, uint32_t id, Buffer& out, const Buffer& in, pframes_t n_samples, framecnt_t dst_offset = 0, framecnt_t src_offset = 0);
/** zero all buffers */
void flush();
private:
framecnt_t _max_delay;
framecnt_t _buf_size;
framecnt_t _delay;
ChanCount _count;
struct DelayBuffer {
public:
DelayBuffer () : buf (0), pos (0) {}
DelayBuffer (DataType dt, size_t capacity)
: buf (Buffer::create (dt, capacity)), pos (0) {}
~DelayBuffer () { delete buf; }
Buffer * buf;
framepos_t pos;
};
typedef std::vector<DelayBuffer*> BufferVec;
// Vector of vectors, indexed by DataType
std::vector<BufferVec> _buffers;
void ensure_buffers(DataType type, size_t num_buffers, size_t buffer_capacity);
void clear ();
};
} // namespace ARDOUR
#endif // __ardour_fixed_delay_h__
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