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/*
Copyright (C) 2006 Paul Davis
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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef __ardour_midi_ring_buffer_h__
#define __ardour_midi_ring_buffer_h__
#include <iostream>
#include <algorithm>
#include "evoral/EventRingBuffer.hpp"
#include "ardour/types.h"
#include "ardour/buffer.h"
#include "ardour/midi_state_tracker.h"
namespace ARDOUR {
class MidiBuffer;
/** A RingBuffer for (MIDI) events.
*
* This is simply a wrapper around a raw ringbuffer which writes/reads events
* as flat placked blobs.
* The buffer looks like this:
*
* [timestamp][type][size][size bytes of raw MIDI][timestamp][type][size](etc...)
*/
template<typename T>
class MidiRingBuffer : public Evoral::EventRingBuffer<T> {
public:
/** @param size Size in bytes.
*/
MidiRingBuffer(size_t size)
: Evoral::EventRingBuffer<T>(size)
, _channel_mask(0x0000FFFF)
{}
inline bool read_prefix(T* time, Evoral::EventType* type, uint32_t* size);
inline bool read_contents(uint32_t size, uint8_t* buf);
size_t read(MidiBuffer& dst, framepos_t start, framepos_t end, framecnt_t offset=0, bool stop_on_overflow_in_destination=false);
inline uint32_t write(T time, Evoral::EventType type, uint32_t size, const uint8_t* buf);
void dump(std::ostream& dst);
void flush (framepos_t start, framepos_t end);
/** Set the channel filtering mode.
* @param mask If mode is FilterChannels, each bit represents a midi channel:
* bit 0 = channel 0, bit 1 = channel 1 etc. the read and write methods will only
* process events whose channel bit is 1.
* If mode is ForceChannel, mask is simply a channel number which all events will
* be forced to while reading.
*/
void set_channel_mode(ChannelMode mode, uint16_t mask) {
g_atomic_int_set(&_channel_mask, (uint32_t(mode) << 16) | uint32_t(mask));
}
ChannelMode get_channel_mode() const {
return static_cast<ChannelMode>((g_atomic_int_get(&_channel_mask) & 0xFFFF0000) >> 16);
}
uint16_t get_channel_mask() const {
return g_atomic_int_get(&_channel_mask) & 0x0000FFFF;
}
void reset_tracker ();
void loop_resolve (MidiBuffer& dst, framepos_t);
protected:
inline bool is_channel_event(uint8_t event_type_byte) {
// mask out channel information
event_type_byte &= 0xF0;
// midi channel events range from 0x80 to 0xE0
return (0x80 <= event_type_byte) && (event_type_byte <= 0xE0);
}
inline bool is_note_on(uint8_t event_type_byte) {
// mask out channel information
return (event_type_byte & 0xF0) == MIDI_CMD_NOTE_ON;
}
inline bool is_note_off(uint8_t event_type_byte) {
// mask out channel information
return (event_type_byte & 0xF0) == MIDI_CMD_NOTE_OFF;
}
private:
volatile uint32_t _channel_mask; // 16 bits mode, 16 bits mask
MidiStateTracker _tracker;
};
/** Read the time and size of an event. This call MUST be immediately proceeded
* by a call to read_contents (or the read pointer will be garbage).
*/
template<typename T>
inline bool
MidiRingBuffer<T>::read_prefix(T* time, Evoral::EventType* type, uint32_t* size)
{
if (PBD::RingBufferNPT<uint8_t>::read((uint8_t*)time, sizeof(T)) != sizeof (T)) {
return false;
}
if (PBD::RingBufferNPT<uint8_t>::read((uint8_t*)type, sizeof(Evoral::EventType)) != sizeof (Evoral::EventType)) {
return false;
}
if (PBD::RingBufferNPT<uint8_t>::read((uint8_t*)size, sizeof(uint32_t)) != sizeof (uint32_t)) {
return false;
}
return true;
}
/** Read the content of an event. This call MUST be immediately preceded
* by a call to read_prefix (or the returned even will be garbage).
*/
template<typename T>
inline bool
MidiRingBuffer<T>::read_contents(uint32_t size, uint8_t* buf)
{
return PBD::RingBufferNPT<uint8_t>::read(buf, size) == size;
}
template<typename T>
inline uint32_t
MidiRingBuffer<T>::write(T time, Evoral::EventType type, uint32_t size, const uint8_t* buf)
{
assert(size > 0);
uint8_t status = buf[0];
// Ignore event if it doesn't match channel filter
if (is_channel_event(status)) {
ChannelMode mode = get_channel_mode();
if (mode == FilterChannels) {
const uint8_t channel = status & 0x0F;
if (!(get_channel_mask() & (1L << channel))) {
return 0;
}
} else if (mode == ForceChannel) {
uint8_t* tmpbuf = (uint8_t*) malloc(size);
assert(tmpbuf);
memcpy(tmpbuf, buf, size);
tmpbuf[0] = (tmpbuf[0] & 0xF0) | (get_channel_mask() & 0x0F);
uint32_t bytes_written = Evoral::EventRingBuffer<T>::write(time, type, size, tmpbuf);
free(tmpbuf);
return bytes_written;
}
}
return Evoral::EventRingBuffer<T>::write(time, type, size, buf);
}
} // namespace ARDOUR
#endif // __ardour_midi_ring_buffer_h__
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