summaryrefslogtreecommitdiff
path: root/src/music/extmidi.cpp
blob: c532e9d44674a55f78ef9783741aa151d614d9d9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
/* $Id$ */

/*
 * This file is part of OpenTTD.
 * OpenTTD 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, version 2.
 * OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file extmidi.cpp Playing music via an external player. */

#include "../stdafx.h"
#include "../debug.h"
#include "../string_func.h"
#include "../core/alloc_func.hpp"
#include "../sound/sound_driver.hpp"
#include "../video/video_driver.hpp"
#include "../gfx_func.h"
#include "extmidi.h"
#include "../base_media_base.h"
#include <fcntl.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <signal.h>
#include <sys/stat.h>
#include <errno.h>

#include "../safeguards.h"

#ifndef EXTERNAL_PLAYER
/** The default external midi player. */
#define EXTERNAL_PLAYER "timidity"
#endif

/** Factory for the midi player that uses external players. */
static FMusicDriver_ExtMidi iFMusicDriver_ExtMidi;

const char *MusicDriver_ExtMidi::Start(const char * const * parm)
{
	if (strcmp(VideoDriver::GetInstance()->GetName(), "allegro") == 0 ||
			strcmp(SoundDriver::GetInstance()->GetName(), "allegro") == 0) {
		return "the extmidi driver does not work when Allegro is loaded.";
	}

	const char *command = GetDriverParam(parm, "cmd");
#ifndef MIDI_ARG
	if (StrEmpty(command)) command = EXTERNAL_PLAYER;
#else
	if (StrEmpty(command)) command = EXTERNAL_PLAYER " " MIDI_ARG;
#endif

	/* Count number of arguments, but include 3 extra slots: 1st for command, 2nd for song title, and 3rd for terminating NULL. */
	uint num_args = 3;
	for (const char *t = command; *t != '\0'; t++) if (*t == ' ') num_args++;

	this->params = CallocT<char *>(num_args);
	this->params[0] = stredup(command);

	/* Replace space with \0 and add next arg to params */
	uint p = 1;
	while (true) {
		this->params[p] = strchr(this->params[p - 1], ' ');
		if (this->params[p] == NULL) break;

		this->params[p][0] = '\0';
		this->params[p]++;
		p++;
	}

	/* Last parameter is the song file. */
	this->params[p] = this->song;

	this->song[0] = '\0';
	this->pid = -1;
	return NULL;
}

void MusicDriver_ExtMidi::Stop()
{
	free(params[0]);
	free(params);
	this->song[0] = '\0';
	this->DoStop();
}

void MusicDriver_ExtMidi::PlaySong(const MusicSongInfo &song)
{
	if (song.filetype != MTT_STANDARDMIDI) return;

	strecpy(this->song, song.filename, lastof(this->song));
	this->DoStop();
}

void MusicDriver_ExtMidi::StopSong()
{
	this->song[0] = '\0';
	this->DoStop();
}

bool MusicDriver_ExtMidi::IsSongPlaying()
{
	if (this->pid != -1 && waitpid(this->pid, NULL, WNOHANG) == this->pid) {
		this->pid = -1;
	}
	if (this->pid == -1 && this->song[0] != '\0') this->DoPlay();
	return this->pid != -1;
}

void MusicDriver_ExtMidi::SetVolume(byte vol)
{
	DEBUG(driver, 1, "extmidi: set volume not implemented");
}

void MusicDriver_ExtMidi::DoPlay()
{
	this->pid = fork();
	switch (this->pid) {
		case 0: {
			close(0);
			int d = open("/dev/null", O_RDONLY);
			if (d != -1 && dup2(d, 1) != -1 && dup2(d, 2) != -1) {
				execvp(this->params[0], this->params);
			}
			_exit(1);
		}

		case -1:
			DEBUG(driver, 0, "extmidi: couldn't fork: %s", strerror(errno));
			FALLTHROUGH;

		default:
			this->song[0] = '\0';
			break;
	}
}

void MusicDriver_ExtMidi::DoStop()
{
	if (this->pid <= 0) return;

	/* First try to gracefully stop for about five seconds;
	 * 5 seconds = 5000 milliseconds, 10 ms per cycle => 500 cycles. */
	for (int i = 0; i < 500; i++) {
		kill(this->pid, SIGTERM);
		if (waitpid(this->pid, NULL, WNOHANG) == this->pid) {
			/* It has shut down, so we are done */
			this->pid = -1;
			return;
		}
		/* Wait 10 milliseconds. */
		CSleep(10);
	}

	DEBUG(driver, 0, "extmidi: gracefully stopping failed, trying the hard way");
	/* Gracefully stopping failed. Do it the hard way
	 * and wait till the process finally died. */
	kill(this->pid, SIGKILL);
	waitpid(this->pid, NULL, 0);
	this->pid = -1;
}