2 Copyright (C) 2006-2008 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 #include "pbd/compose.h"
20 #include "pbd/error.h"
22 #include "ardour/debug.h"
23 #include "ardour/midi_ring_buffer.h"
24 #include "ardour/midi_buffer.h"
25 #include "ardour/event_type_map.h"
32 /** Read a block of MIDI events from this buffer into a MidiBuffer.
34 * Timestamps of events returned are relative to start (i.e. event with stamp 0
35 * occurred at start), with offset added.
39 MidiRingBuffer<T>::read(MidiBuffer& dst, framepos_t start, framepos_t end, framecnt_t offset, bool stop_on_overflow_in_dst)
41 if (this->read_space() == 0) {
46 Evoral::EventType ev_type;
49 /* If we see the end of a loop during this read, we must write the events after it
50 to the MidiBuffer with adjusted times. The situation is as follows:
52 session frames----------------------------->
55 start_of_loop start end_of_loop
57 The MidiDiskstream::read method which will have happened before this checks for
58 loops ending, and helpfully inserts a magic LoopEvent into the ringbuffer. After this,
59 the MidiDiskstream continues to write events with their proper session frame times,
60 so after the LoopEvent event times will go backwards (ie non-monotonically).
62 Once we hit end_of_loop, we need to fake it to make it look as though the loop has been
63 immediately repeated. Say that an event E after the end_of_loop in the ringbuffer
64 has time E_t, which is a time in session frames. Its offset from the start
65 of the loop will be E_t - start_of_loop. Its `faked' time will therefore be
66 end_of_loop + E_t - start_of_loop. And so its port-buffer-relative time (for
67 writing to the MidiBuffer) will be end_of_loop + E_t - start_of_loop - start.
69 The subtraction of start is already taken care of, so if we see a LoopEvent, we'll
70 set up loop_offset to equal end_of_loop - start_of_loop, so that given an event
71 time E_t in the ringbuffer we can get the port-buffer-relative time as
75 frameoffset_t loop_offset = 0;
79 const size_t prefix_size = sizeof(T) + sizeof(Evoral::EventType) + sizeof(uint32_t);
81 while (this->read_space() >= prefix_size) {
83 uint8_t peekbuf[prefix_size];
86 success = this->peek (peekbuf, prefix_size);
87 /* this cannot fail, because we've already verified that there
88 is prefix_space to read
92 ev_time = *((T*) peekbuf);
93 ev_type = *((Evoral::EventType*)(peekbuf + sizeof (T)));
94 ev_size = *((uint32_t*)(peekbuf + sizeof(T) + sizeof (Evoral::EventType)));
96 if (ev_time + loop_offset >= end) {
97 DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose ("MRB event @ %1 past end @ %2\n", ev_time, end));
99 } else if (ev_time + loop_offset < start) {
100 DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose ("MRB event @ %1 before start @ %2\n", ev_time, start));
103 DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose ("MRB event @ %1 in range %2 .. %3\n", ev_time, start, end));
106 assert(ev_time >= start);
111 // This event marks a loop end (i.e. the next event's timestamp
112 // will be non-monotonic). Don't write it into the buffer - the
113 // significance of this event ends here.
115 if (ev_type == LoopEventType) {
116 assert (ev_size == sizeof (framepos_t));
117 framepos_t loop_start;
118 read_contents (ev_size, (uint8_t *) &loop_start);
119 loop_offset = ev_time - loop_start;
120 _tracker.resolve_notes (dst, ev_time);
124 /* we're good to go ahead and read the data now but since we
125 * have the prefix data already, just skip over that
127 this->increment_read_ptr (prefix_size);
128 ev_time += loop_offset;
131 success = this->peek (&status, sizeof(uint8_t));
132 assert(success); // If this failed, buffer is corrupt, all hope is lost
134 // Ignore event if it doesn't match channel filter
135 if (is_channel_event(status) && get_channel_mode() == FilterChannels) {
136 const uint8_t channel = status & 0x0F;
137 if (!(get_channel_mask() & (1L << channel))) {
138 DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose ("MRB skipping event (%3 bytes) due to channel mask (mask = %1 chn = %2)\n",
139 get_channel_mask(), (int) channel, ev_size));
140 this->increment_read_ptr (ev_size); // Advance read pointer to next event
145 /* lets see if we are going to be able to write this event into dst.
147 uint8_t* write_loc = dst.reserve (ev_time, ev_size);
148 if (write_loc == 0) {
149 if (stop_on_overflow_in_dst) {
150 DEBUG_TRACE (DEBUG::MidiDiskstreamIO, string_compose ("MidiRingBuffer: overflow in destination MIDI buffer, stopped after %1 events\n", count));
153 error << "MRB: Unable to reserve space in buffer, event skipped" << endmsg;
154 this->increment_read_ptr (ev_size); // Advance read pointer to next event
158 // write MIDI buffer contents
159 success = read_contents (ev_size, write_loc);
162 if (DEBUG::MidiDiskstreamIO && PBD::debug_bits) {
164 DEBUG_STR_APPEND(a, string_compose ("wrote MidiEvent to Buffer (time=%1, start=%2 offset=%3)", ev_time, start, offset));
165 for (size_t i=0; i < ev_size; ++i) {
166 DEBUG_STR_APPEND(a,hex);
167 DEBUG_STR_APPEND(a,"0x");
168 DEBUG_STR_APPEND(a,(int)write_loc[i]);
169 DEBUG_STR_APPEND(a,' ');
171 DEBUG_STR_APPEND(a,'\n');
172 DEBUG_TRACE (DEBUG::MidiDiskstreamIO, DEBUG_STR(a).str());
178 if (is_note_on(write_loc[0]) ) {
179 _tracker.add (write_loc[1], write_loc[0] & 0xf);
180 } else if (is_note_off(write_loc[0])) {
181 _tracker.remove (write_loc[1], write_loc[0] & 0xf);
184 if (is_channel_event(status) && get_channel_mode() == ForceChannel) {
185 write_loc[0] = (write_loc[0] & 0xF0) | (get_channel_mask() & 0x0F);
189 cerr << "WARNING: error reading event contents from MIDI ring" << endl;
198 MidiRingBuffer<T>::dump(ostream& str)
202 if ((rspace = this->read_space()) == 0) {
203 str << "MRB::dump: empty\n";
208 Evoral::EventType ev_type;
211 RingBufferNPT<uint8_t>::rw_vector vec;
212 RingBufferNPT<uint8_t>::get_read_vector (&vec);
214 if (vec.len[0] == 0) {
218 str << this << ": Dump size = " << vec.len[0] + vec.len[1]
219 << " r@ " << RingBufferNPT<uint8_t>::get_read_ptr()
220 << " w@" << RingBufferNPT<uint8_t>::get_write_ptr() << endl;
223 uint8_t *buf = new uint8_t[vec.len[0] + vec.len[1]];
224 memcpy (buf, vec.buf[0], vec.len[0]);
227 memcpy (buf+vec.len[1], vec.buf[1], vec.len[1]);
231 const uint8_t* end = buf + vec.len[0] + vec.len[1];
235 memcpy (&ev_time, data, sizeof (T));
237 str << "\ttime " << ev_time;
240 str << "(incomplete)\n ";
244 memcpy (&ev_type, data, sizeof (ev_type));
245 data += sizeof (ev_type);
246 str << " type " << ev_type;
249 str << "(incomplete)\n";
253 memcpy (&ev_size, data, sizeof (ev_size));
254 data += sizeof (ev_size);
255 str << " size " << ev_size;
258 str << "(incomplete)\n";
262 for (uint32_t i = 0; i != ev_size && data < end; ++i) {
263 str << ' ' << hex << (int) data[i] << dec;
276 MidiRingBuffer<T>::reset_tracker ()
281 template class MidiRingBuffer<framepos_t>;
283 } // namespace ARDOUR