midi_buffer.cc

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/*
    Copyright (C) 2006-2007 Paul Davis
    Author: David Robillard

    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.
*/

#include <iostream>

#include "pbd/malign.h"
#include "pbd/compose.h"
#include "pbd/debug.h"
#include "pbd/stacktrace.h"

#include "ardour/debug.h"
#include "ardour/midi_buffer.h"

using namespace std;
using namespace ARDOUR;
using namespace PBD;

// FIXME: mirroring for MIDI buffers?
MidiBuffer::MidiBuffer(size_t capacity)
        : Buffer (DataType::MIDI)
        , _data (0)
{
        if (capacity) {
                resize (capacity);
                silence (capacity);
        }
}

MidiBuffer::~MidiBuffer()
{
        free(_data);
}

void
MidiBuffer::resize(size_t size)
{
        if (_data && size < _capacity) {

                if (_size < size) {
                        /* truncate */
                        _size = size;
                }

                return;
        }

        free (_data);

        cache_aligned_malloc ((void**) &_data, size);

        _size = 0;
        _capacity = size;

        assert(_data);
}

void
MidiBuffer::copy(const MidiBuffer& copy)
{
        assert(_capacity >= copy._size);
        _size = copy._size;
        memcpy(_data, copy._data, copy._size);
}


void
MidiBuffer::read_from (const Buffer& src, framecnt_t nframes, framecnt_t dst_offset, framecnt_t src_offset)
{
        assert (src.type() == DataType::MIDI);
        assert (&src != this);

        const MidiBuffer& msrc = (const MidiBuffer&) src;

        assert (_capacity >= msrc.size());

        if (dst_offset == 0) {
                clear ();
                assert (_size == 0);
        }

        /* XXX use dst_offset somehow */

        for (MidiBuffer::const_iterator i = msrc.begin(); i != msrc.end(); ++i) {
                const Evoral::MIDIEvent<TimeType> ev(*i, false);
                if (ev.time() >= src_offset && ev.time() < (nframes+src_offset)) {
                        push_back (ev);
                } else {
                        cerr << "MIDI event @ " <<  ev.time() << " skipped, not within range "
                             << src_offset << " .. " << (nframes + src_offset) << endl;
                }
        }

        _silent = src.silent();
}

void
MidiBuffer::merge_from (const Buffer& src, framecnt_t /*nframes*/, framecnt_t /*dst_offset*/, framecnt_t /*src_offset*/)
{
        const MidiBuffer* mbuf = dynamic_cast<const MidiBuffer*>(&src);
        assert (mbuf);
        assert (mbuf != this);

        /* XXX use nframes, and possible offsets */
        merge_in_place (*mbuf);
}

bool
MidiBuffer::push_back(const Evoral::MIDIEvent<TimeType>& ev)
{
        const size_t stamp_size = sizeof(TimeType);

        if (_size + stamp_size + ev.size() >= _capacity) {
                cerr << "MidiBuffer::push_back failed (buffer is full)" << endl;
                PBD::stacktrace (cerr, 20);
                return false;
        }

        if (!Evoral::midi_event_is_valid(ev.buffer(), ev.size())) {
                cerr << "WARNING: MidiBuffer ignoring illegal MIDI event" << endl;
                return false;
        }

        push_back(ev.time(), ev.size(), ev.buffer());

        return true;
}


bool
MidiBuffer::push_back(TimeType time, size_t size, const uint8_t* data)
{
        const size_t stamp_size = sizeof(TimeType);

#ifndef NDEBUG
        if (DEBUG::MidiIO & PBD::debug_bits) {
                DEBUG_STR_DECL(a);
                DEBUG_STR_APPEND(a, string_compose ("midibuffer %1 push event @ %2 sz %3 ", this, time, size));
                for (size_t i=0; i < size; ++i) {
                        DEBUG_STR_APPEND(a,hex);
                        DEBUG_STR_APPEND(a,"0x");
                        DEBUG_STR_APPEND(a,(int)data[i]);
                        DEBUG_STR_APPEND(a,' ');
                }
                DEBUG_STR_APPEND(a,'\n');
                DEBUG_TRACE (DEBUG::MidiIO, DEBUG_STR(a).str());
        }
#endif

        if (_size + stamp_size + size >= _capacity) {
                cerr << "MidiBuffer::push_back2 failed (buffer is full; _size = " << _size << " capacity " 
                     << _capacity << " stamp " << stamp_size << " size = " << size << ")" << endl;
                PBD::stacktrace (cerr, 20);
                return false;
        }

        if (!Evoral::midi_event_is_valid(data, size)) {
                cerr << "WARNING: MidiBuffer ignoring illegal MIDI event" << endl;
                return false;
        }

        uint8_t* const write_loc = _data + _size;
        *(reinterpret_cast<TimeType*>((uintptr_t)write_loc)) = time;
        memcpy(write_loc + stamp_size, data, size);

        _size += stamp_size + size;
        _silent = false;

        return true;
}

bool
MidiBuffer::insert_event(const Evoral::MIDIEvent<TimeType>& ev)
{
        if (size() == 0) {
                return push_back(ev);
        }

        const size_t stamp_size = sizeof(TimeType);
        const size_t bytes_to_merge = stamp_size + ev.size();

        if (_size + bytes_to_merge >= _capacity) {
                cerr << "MidiBuffer::push_back failed (buffer is full)" << endl;
                PBD::stacktrace (cerr, 20);
                return false;
        }

        TimeType t = ev.time();

        ssize_t insert_offset = -1;
        for (MidiBuffer::iterator m = begin(); m != end(); ++m) {
                if ((*m).time() < t) {
                        continue;
                }
                if ((*m).time() == t) {
                        const uint8_t our_midi_status_byte = *(_data + m.offset + sizeof (TimeType));
                        if (second_simultaneous_midi_byte_is_first (ev.type(), our_midi_status_byte)) {
                                continue;
                        }
                }
                insert_offset = m.offset;
                break;
        }
        if (insert_offset == -1) {
                return push_back(ev);
        }

        // don't use memmove - it may use malloc(!)
        // memmove (_data + insert_offset + bytes_to_merge, _data + insert_offset, _size - insert_offset);
        for (ssize_t a = _size + bytes_to_merge - 1, b = _size - 1; b >= insert_offset; --b, --a) {
                _data[a] = _data[b];
        }

        uint8_t* const write_loc = _data + insert_offset;
        *(reinterpret_cast<TimeType*>((uintptr_t)write_loc)) = t;
        memcpy(write_loc + stamp_size, ev.buffer(), ev.size());

        _size += bytes_to_merge;

        return true;
}

uint32_t
MidiBuffer::write(TimeType time, Evoral::EventType type, uint32_t size, const uint8_t* buf)
{
        insert_event(Evoral::MIDIEvent<TimeType>(type, time, size, const_cast<uint8_t*>(buf)));
        return size;
}

uint8_t*
MidiBuffer::reserve(TimeType time, size_t size)
{
        const size_t stamp_size = sizeof(TimeType);
        if (_size + stamp_size + size >= _capacity) {
                return 0;
        }

        // write timestamp
        uint8_t* write_loc = _data + _size;
        *(reinterpret_cast<TimeType*>((uintptr_t)write_loc)) = time;

        // move write_loc to begin of MIDI buffer data to write to
        write_loc += stamp_size;

        _size += stamp_size + size;
        _silent = false;

        return write_loc;
}


void
MidiBuffer::silence (framecnt_t /*nframes*/, framecnt_t /*offset*/)
{
        /* XXX iterate over existing events, find all in range given by offset & nframes,
           and delete them.
        */

        _size = 0;
        _silent = true;
}

bool
MidiBuffer::second_simultaneous_midi_byte_is_first (uint8_t a, uint8_t b)
{
        bool b_first = false;

        /* two events at identical times. we need to determine
           the order in which they should occur.
           
           the rule is:
           
           Controller messages
           Program Change
           Note Off
           Note On
           Note Pressure
           Channel Pressure
           Pitch Bend
        */
        
        if ((a) >= 0xf0 || (b) >= 0xf0 || ((a & 0xf) != (b & 0xf))) {
                
                /* if either message is not a channel message, or if the channels are
                 * different, we don't care about the type.
                 */
                
                b_first = true;
                
        } else {
                
                switch (b & 0xf0) {
                case MIDI_CMD_CONTROL:
                        b_first = true;
                        break;
                        
                case MIDI_CMD_PGM_CHANGE:
                        switch (a & 0xf0) {
                        case MIDI_CMD_CONTROL:
                                break;
                        case MIDI_CMD_PGM_CHANGE:
                        case MIDI_CMD_NOTE_OFF:
                        case MIDI_CMD_NOTE_ON:
                        case MIDI_CMD_NOTE_PRESSURE:
                        case MIDI_CMD_CHANNEL_PRESSURE:
                        case MIDI_CMD_BENDER:
                                b_first = true;
                        }
                        break;
                        
                case MIDI_CMD_NOTE_OFF:
                        switch (a & 0xf0) {
                        case MIDI_CMD_CONTROL:
                        case MIDI_CMD_PGM_CHANGE:
                                break;
                        case MIDI_CMD_NOTE_OFF:
                        case MIDI_CMD_NOTE_ON:
                        case MIDI_CMD_NOTE_PRESSURE:
                        case MIDI_CMD_CHANNEL_PRESSURE:
                        case MIDI_CMD_BENDER:
                                b_first = true;
                        }
                        break;
                        
                case MIDI_CMD_NOTE_ON:
                        switch (a & 0xf0) {
                        case MIDI_CMD_CONTROL:
                        case MIDI_CMD_PGM_CHANGE:
                        case MIDI_CMD_NOTE_OFF:
                                break;
                        case MIDI_CMD_NOTE_ON:
                        case MIDI_CMD_NOTE_PRESSURE:
                        case MIDI_CMD_CHANNEL_PRESSURE:
                        case MIDI_CMD_BENDER:
                                b_first = true;
                        }
                        break;
                case MIDI_CMD_NOTE_PRESSURE:
                        switch (a & 0xf0) {
                        case MIDI_CMD_CONTROL:
                        case MIDI_CMD_PGM_CHANGE:
                        case MIDI_CMD_NOTE_OFF:
                        case MIDI_CMD_NOTE_ON:
                                break;
                        case MIDI_CMD_NOTE_PRESSURE:
                        case MIDI_CMD_CHANNEL_PRESSURE:
                        case MIDI_CMD_BENDER:
                                b_first = true;
                        }
                        break;
                        
                case MIDI_CMD_CHANNEL_PRESSURE:
                        switch (a & 0xf0) {
                        case MIDI_CMD_CONTROL:
                        case MIDI_CMD_PGM_CHANGE:
                        case MIDI_CMD_NOTE_OFF:
                        case MIDI_CMD_NOTE_ON:
                        case MIDI_CMD_NOTE_PRESSURE:
                                break;
                        case MIDI_CMD_CHANNEL_PRESSURE:
                        case MIDI_CMD_BENDER:
                                b_first = true;
                        }
                        break;
                case MIDI_CMD_BENDER:
                        switch (a & 0xf0) {
                        case MIDI_CMD_CONTROL:
                        case MIDI_CMD_PGM_CHANGE:
                        case MIDI_CMD_NOTE_OFF:
                        case MIDI_CMD_NOTE_ON:
                        case MIDI_CMD_NOTE_PRESSURE:
                        case MIDI_CMD_CHANNEL_PRESSURE:
                                break;
                        case MIDI_CMD_BENDER:
                                b_first = true;
                        }
                        break;
                }
        }
        
        return b_first;
}
        
bool
MidiBuffer::merge_in_place (const MidiBuffer &other)
{
        if (other.size() && size()) {
                DEBUG_TRACE (DEBUG::MidiIO, string_compose ("merge in place, sizes %1/%2\n", size(), other.size()));
        }

        if (other.size() == 0) {
                return true;
        }

        if (size() == 0) {
                copy (other);
                return true;
        }

        if (size() + other.size() > _capacity) {
                return false;
        }

        const_iterator them = other.begin();
        iterator us = begin();

        while (them != other.end()) {

                size_t bytes_to_merge;
                ssize_t merge_offset;

                /* gather up total size of events that are earlier than
                   the event referenced by "us"
                */

                merge_offset = -1;
                bytes_to_merge = 0;

                while (them != other.end() && (*them).time() < (*us).time()) {
                        if (merge_offset == -1) {
                                merge_offset = them.offset;
                        }
                        bytes_to_merge += sizeof (TimeType) + (*them).size();
                        ++them;
                }

                /* "them" now points to either:
                 *
                 * 1) an event that has the same or later timestamp than the
                 *        event pointed to by "us"
                 *
                 * OR
                 *
                 * 2) the end of the "other" buffer
                 *
                 * if "sz" is non-zero, there is data to be merged from "other"
                 * into this buffer before we do anything else, corresponding
                 * to the events from "other" that we skipped while advancing
                 * "them". 
                 */

                if (bytes_to_merge) {
                        assert(merge_offset >= 0);
                        /* move existing */
                        memmove (_data + us.offset + bytes_to_merge, _data + us.offset, _size - us.offset);
                        /* increase _size */
                        _size += bytes_to_merge;
                        assert (_size <= _capacity);
                        /* insert new stuff */
                        memcpy  (_data + us.offset, other._data + merge_offset, bytes_to_merge);
                        /* update iterator to our own events. this is a miserable hack */
                        us.offset += bytes_to_merge;
                } 

                /* if we're at the end of the other buffer, we're done */

                if (them == other.end()) {
                        break;
                }

                /* if we have two messages messages with the same timestamp. we
                 * must order them correctly.
                 */

                if ((*us).time() == (*them).time()) {

                        DEBUG_TRACE (DEBUG::MidiIO, 
                                     string_compose ("simultaneous MIDI events discovered during merge, times %1/%2 status %3/%4\n",
                                                     (*us).time(), (*them).time(),
                                                     (int) *(_data + us.offset + sizeof (TimeType)),
                                                     (int) *(other._data + them.offset + sizeof (TimeType))));
                        
                        uint8_t our_midi_status_byte = *(_data + us.offset + sizeof (TimeType));
                        uint8_t their_midi_status_byte = *(other._data + them.offset + sizeof (TimeType));
                        bool them_first = second_simultaneous_midi_byte_is_first (our_midi_status_byte, their_midi_status_byte);
                        
                        DEBUG_TRACE (DEBUG::MidiIO, string_compose ("other message came first ? %1\n", them_first));
                        
                        if (!them_first) {
                                /* skip past our own event */
                                ++us;
                        }
                                
                        bytes_to_merge = sizeof (TimeType) + (*them).size();
                        
                        /* move our remaining events later in the buffer by
                         * enough to fit the one message we're going to merge
                         */

                        memmove (_data + us.offset + bytes_to_merge, _data + us.offset, _size - us.offset);
                        /* increase _size */
                        _size += bytes_to_merge;
                        assert(_size <= _capacity);
                        /* insert new stuff */
                        memcpy  (_data + us.offset, other._data + them.offset, bytes_to_merge);
                        /* update iterator to our own events. this is a miserable hack */
                        us.offset += bytes_to_merge;
                        /* 'us' is now an iterator to the event right after the
                           new ones that we merged
                        */
                        if (them_first) {
                                /* need to skip the event pointed to by 'us'
                                   since its at the same time as 'them'
                                   (still), and we'll enter 
                                */

                                if (us != end()) {
                                        ++us;
                                }
                        }

                        /* we merged one event from the other buffer, so
                         * advance the iterator there.
                         */

                        ++them;

                } else {
                        
                        /* advance past our own events to get to the correct insertion
                           point for the next event(s) from "other"
                        */
                
                        while (us != end() && (*us).time() <= (*them).time()) {
                                ++us;
                        }
                }

                /* check to see if we reached the end of this buffer while
                 * looking for the insertion point.
                 */

                if (us == end()) {

                        /* just append the rest of other and we're done*/
                        
                        memcpy (_data + us.offset, other._data + them.offset, other._size - them.offset);
                        _size += other._size - them.offset;
                        assert(_size <= _capacity);
                        break;
                } 
        }

        return true;
}