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__
25 #include "evoral/EventRingBuffer.hpp"
27 #include "ardour/types.h"
28 #include "ardour/midi_state_tracker.h"
34 /** A RingBuffer for (MIDI) events.
36 * This is simply a wrapper around a raw ringbuffer which writes/reads events
37 * as flat placked blobs.
38 * The buffer looks like this:
40 * [timestamp][type][size][size bytes of raw MIDI][timestamp][type][size](etc...)
43 class MidiRingBuffer : public Evoral::EventRingBuffer<T> {
45 /** @param size Size in bytes.
47 MidiRingBuffer(size_t size)
48 : Evoral::EventRingBuffer<T>(size)
49 , _channel_mask(0x0000FFFF)
52 inline bool read_prefix(T* time, Evoral::EventType* type, uint32_t* size);
53 inline bool read_contents(uint32_t size, uint8_t* buf);
55 size_t read(MidiBuffer& dst, framepos_t start, framepos_t end, framecnt_t offset=0, bool stop_on_overflow_in_destination=false);
56 inline uint32_t write(T time, Evoral::EventType type, uint32_t size, const uint8_t* buf);
58 void dump(std::ostream& dst);
59 void flush (framepos_t start, framepos_t end);
61 /** Set the channel filtering mode.
62 * @param mask If mode is FilterChannels, each bit represents a midi channel:
63 * bit 0 = channel 0, bit 1 = channel 1 etc. the read and write methods will only
64 * process events whose channel bit is 1.
65 * If mode is ForceChannel, mask is simply a channel number which all events will
66 * be forced to while reading.
68 void set_channel_mode(ChannelMode mode, uint16_t mask) {
69 g_atomic_int_set(&_channel_mask, (uint32_t(mode) << 16) | uint32_t(mask));
72 ChannelMode get_channel_mode() const {
73 return static_cast<ChannelMode>((g_atomic_int_get(&_channel_mask) & 0xFFFF0000) >> 16);
76 uint16_t get_channel_mask() const {
77 return g_atomic_int_get(&_channel_mask) & 0x0000FFFF;
80 void reset_tracker ();
81 void loop_resolve (MidiBuffer& dst, framepos_t);
84 inline bool is_channel_event(uint8_t event_type_byte) {
85 // mask out channel information
86 event_type_byte &= 0xF0;
87 // midi channel events range from 0x80 to 0xE0
88 return (0x80 <= event_type_byte) && (event_type_byte <= 0xE0);
91 inline bool is_note_on(uint8_t event_type_byte) {
92 // mask out channel information
93 return (event_type_byte & 0xF0) == MIDI_CMD_NOTE_ON;
96 inline bool is_note_off(uint8_t event_type_byte) {
97 // mask out channel information
98 return (event_type_byte & 0xF0) == MIDI_CMD_NOTE_OFF;
102 volatile uint32_t _channel_mask; // 16 bits mode, 16 bits mask
103 MidiStateTracker _tracker;
107 /** Read the time and size of an event. This call MUST be immediately proceeded
108 * by a call to read_contents (or the read pointer will be garbage).
112 MidiRingBuffer<T>::read_prefix(T* time, Evoral::EventType* type, uint32_t* size)
114 if (PBD::RingBufferNPT<uint8_t>::read((uint8_t*)time, sizeof(T)) != sizeof (T)) {
118 if (PBD::RingBufferNPT<uint8_t>::read((uint8_t*)type, sizeof(Evoral::EventType)) != sizeof (Evoral::EventType)) {
122 if (PBD::RingBufferNPT<uint8_t>::read((uint8_t*)size, sizeof(uint32_t)) != sizeof (uint32_t)) {
130 /** Read the content of an event. This call MUST be immediately preceded
131 * by a call to read_prefix (or the returned even will be garbage).
135 MidiRingBuffer<T>::read_contents(uint32_t size, uint8_t* buf)
137 return PBD::RingBufferNPT<uint8_t>::read(buf, size) == size;
142 MidiRingBuffer<T>::write(T time, Evoral::EventType type, uint32_t size, const uint8_t* buf)
145 uint8_t status = buf[0];
147 // Ignore event if it doesn't match channel filter
148 if (is_channel_event(status)) {
149 ChannelMode mode = get_channel_mode();
150 if (mode == FilterChannels) {
151 const uint8_t channel = status & 0x0F;
152 if (!(get_channel_mask() & (1L << channel))) {
155 } else if (mode == ForceChannel) {
156 uint8_t* tmpbuf = (uint8_t*) malloc(size);
158 memcpy(tmpbuf, buf, size);
160 tmpbuf[0] = (tmpbuf[0] & 0xF0) | (get_channel_mask() & 0x0F);
162 uint32_t bytes_written = Evoral::EventRingBuffer<T>::write(time, type, size, tmpbuf);
164 return bytes_written;
168 return Evoral::EventRingBuffer<T>::write(time, type, size, buf);
172 } // namespace ARDOUR
174 #endif // __ardour_midi_ring_buffer_h__