2 Copyright (C) 2006 Paul Davis
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 #ifndef __ardour_midi_ring_buffer_h__
20 #define __ardour_midi_ring_buffer_h__
24 #include "ardour/types.h"
25 #include "ardour/buffer.h"
26 #include "evoral/EventRingBuffer.hpp"
32 /** A RingBuffer for (MIDI) events.
34 * This is simply a wrapper around a raw ringbuffer which writes/reads events
35 * as flat placked blobs.
36 * The buffer looks like this:
38 * [timestamp][type][size][size bytes of raw MIDI][timestamp][type][size](etc...)
41 class MidiRingBuffer : public Evoral::EventRingBuffer<T> {
43 /** @param size Size in bytes.
45 MidiRingBuffer(size_t size)
46 : Evoral::EventRingBuffer<T>(size)
47 , _channel_mask(0x0000FFFF)
50 inline bool read_prefix(T* time, Evoral::EventType* type, uint32_t* size);
51 inline bool read_contents(uint32_t size, uint8_t* buf);
53 size_t read(MidiBuffer& dst, nframes_t start, nframes_t end, nframes_t offset=0);
55 /** Set the channel filtering mode.
56 * @param mask If mode is FilterChannels, each bit represents a midi channel:
57 * bit 0 = channel 0, bit 1 = channel 1 etc. the read and write methods will only
58 * process events whose channel bit is 1.
59 * If mode is ForceChannel, mask is simply a channel number which all events will
60 * be forced to while reading.
62 void set_channel_mode(ChannelMode mode, uint16_t mask) {
63 g_atomic_int_set(&_channel_mask, (uint32_t(mode) << 16) | uint32_t(mask));
66 ChannelMode get_channel_mode() const {
67 return static_cast<ChannelMode>((g_atomic_int_get(&_channel_mask) & 0xFFFF0000) >> 16);
70 uint16_t get_channel_mask() const {
71 return g_atomic_int_get(&_channel_mask) & 0x0000FFFF;
75 inline bool is_channel_event(uint8_t event_type_byte) {
76 // mask out channel information
77 event_type_byte &= 0xF0;
78 // midi channel events range from 0x80 to 0xE0
79 return (0x80 <= event_type_byte) && (event_type_byte <= 0xE0);
83 volatile uint32_t _channel_mask; // 16 bits mode, 16 bits mask
87 /** Read the time and size of an event. This call MUST be immediately proceeded
88 * by a call to read_contents (or the read pointer will be garbage).
92 MidiRingBuffer<T>::read_prefix(T* time, Evoral::EventType* type, uint32_t* size)
94 bool success = Evoral::EventRingBuffer<T>::full_read(sizeof(T), (uint8_t*)time);
96 success = Evoral::EventRingBuffer<T>::full_read(sizeof(Evoral::EventType), (uint8_t*)type);
98 success = Evoral::EventRingBuffer<T>::full_read(sizeof(uint32_t), (uint8_t*)size);
104 /** Read the content of an event. This call MUST be immediately preceded
105 * by a call to read_prefix (or the returned even will be garbage).
109 MidiRingBuffer<T>::read_contents(uint32_t size, uint8_t* buf)
111 return Evoral::EventRingBuffer<T>::full_read(size, buf);
115 } // namespace ARDOUR
117 #endif // __ardour_midi_ring_buffer_h__