arecordmidi.c

ALSA驱动的一些调试测试工具

	/* ignore events without proper timestamps */
	if (ev->queue != queue || !snd_seq_ev_is_tick(ev))
		return;

	/* determine which track to record to */
	i = ev->dest.port;
	if (i == port_count) {
		if (ev->type == SND_SEQ_EVENT_USR0)
			metronome_pattern(ev->time.tick);
		return;
	}
	if (channel_split) {
		i *= TRACKS_PER_PORT;
		if (snd_seq_ev_is_channel_type(ev))
			i += 1 + (ev->data.note.channel & 0xf);
	}
	if (i >= num_tracks)
		return;
	track = &tracks[i];

	switch (ev->type) {
	case SND_SEQ_EVENT_NOTEON:
		delta_time(track, ev);
		command(track, MIDI_CMD_NOTE_ON | (ev->data.note.channel & 0xf));
		add_byte(track, ev->data.note.note & 0x7f);
		add_byte(track, ev->data.note.velocity & 0x7f);
		break;
	case SND_SEQ_EVENT_NOTEOFF:
		delta_time(track, ev);
		command(track, MIDI_CMD_NOTE_OFF | (ev->data.note.channel & 0xf));
		add_byte(track, ev->data.note.note & 0x7f);
		add_byte(track, ev->data.note.velocity & 0x7f);
		break;
	case SND_SEQ_EVENT_KEYPRESS:
		delta_time(track, ev);
		command(track, MIDI_CMD_NOTE_PRESSURE | (ev->data.note.channel & 0xf));
		add_byte(track, ev->data.note.note & 0x7f);
		add_byte(track, ev->data.note.velocity & 0x7f);
		break;
	case SND_SEQ_EVENT_CONTROLLER:
		delta_time(track, ev);
		command(track, MIDI_CMD_CONTROL | (ev->data.control.channel & 0xf));
		add_byte(track, ev->data.control.param & 0x7f);
		add_byte(track, ev->data.control.value & 0x7f);
		break;
	case SND_SEQ_EVENT_PGMCHANGE:
		delta_time(track, ev);
		command(track, MIDI_CMD_PGM_CHANGE | (ev->data.control.channel & 0xf));
		add_byte(track, ev->data.control.value & 0x7f);
		break;
	case SND_SEQ_EVENT_CHANPRESS:
		delta_time(track, ev);
		command(track, MIDI_CMD_CHANNEL_PRESSURE | (ev->data.control.channel & 0xf));
		add_byte(track, ev->data.control.value & 0x7f);
		break;
	case SND_SEQ_EVENT_PITCHBEND:
		delta_time(track, ev);
		command(track, MIDI_CMD_BENDER | (ev->data.control.channel & 0xf));
		add_byte(track, (ev->data.control.value + 8192) & 0x7f);
		add_byte(track, ((ev->data.control.value + 8192) >> 7) & 0x7f);
		break;
	case SND_SEQ_EVENT_CONTROL14:
		/* create two commands for MSB and LSB */
		delta_time(track, ev);
		command(track, MIDI_CMD_CONTROL | (ev->data.control.channel & 0xf));
		add_byte(track, ev->data.control.param & 0x7f);
		add_byte(track, (ev->data.control.value >> 7) & 0x7f);
		if ((ev->data.control.param & 0x7f) < 0x20) {
			delta_time(track, ev);
			/* running status */
			add_byte(track, (ev->data.control.param & 0x7f) + 0x20);
			add_byte(track, ev->data.control.value & 0x7f);
		}
		break;
	case SND_SEQ_EVENT_NONREGPARAM:
		delta_time(track, ev);
		command(track, MIDI_CMD_CONTROL | (ev->data.control.channel & 0xf));
		add_byte(track, MIDI_CTL_NONREG_PARM_NUM_LSB);
		add_byte(track, ev->data.control.param & 0x7f);
		delta_time(track, ev);
		add_byte(track, MIDI_CTL_NONREG_PARM_NUM_MSB);
		add_byte(track, (ev->data.control.param >> 7) & 0x7f);
		delta_time(track, ev);
		add_byte(track, MIDI_CTL_MSB_DATA_ENTRY);
		add_byte(track, (ev->data.control.value >> 7) & 0x7f);
		delta_time(track, ev);
		add_byte(track, MIDI_CTL_LSB_DATA_ENTRY);
		add_byte(track, ev->data.control.value & 0x7f);
		break;
	case SND_SEQ_EVENT_REGPARAM:
		delta_time(track, ev);
		command(track, MIDI_CMD_CONTROL | (ev->data.control.channel & 0xf));
		add_byte(track, MIDI_CTL_REGIST_PARM_NUM_LSB);
		add_byte(track, ev->data.control.param & 0x7f);
		delta_time(track, ev);
		add_byte(track, MIDI_CTL_REGIST_PARM_NUM_MSB);
		add_byte(track, (ev->data.control.param >> 7) & 0x7f);
		delta_time(track, ev);
		add_byte(track, MIDI_CTL_MSB_DATA_ENTRY);
		add_byte(track, (ev->data.control.value >> 7) & 0x7f);
		delta_time(track, ev);
		add_byte(track, MIDI_CTL_LSB_DATA_ENTRY);
		add_byte(track, ev->data.control.value & 0x7f);
		break;
#if 0	/* ignore */
	case SND_SEQ_EVENT_SONGPOS:
	case SND_SEQ_EVENT_SONGSEL:
	case SND_SEQ_EVENT_QFRAME:
	case SND_SEQ_EVENT_START:
	case SND_SEQ_EVENT_CONTINUE:
	case SND_SEQ_EVENT_STOP:
	case SND_SEQ_EVENT_TUNE_REQUEST:
	case SND_SEQ_EVENT_RESET:
	case SND_SEQ_EVENT_SENSING:
		break;
#endif
	case SND_SEQ_EVENT_SYSEX:
		if (ev->data.ext.len == 0)
			break;
		delta_time(track, ev);
		if (*(unsigned char*)ev->data.ext.ptr == 0xf0)
			command(track, 0xf0), i = 1;
		else
			command(track, 0xf7), i = 0;
		var_value(track, ev->data.ext.len - i);
		for (; i < ev->data.ext.len; ++i)
			add_byte(track, ((unsigned char*)ev->data.ext.ptr)[i]);
		break;
	default:
		return;
	}
	track->used = 1;
}

static void finish_tracks(void)
{
	snd_seq_queue_status_t *queue_status;
	int tick, i, err;

	snd_seq_queue_status_alloca(&queue_status);

	err = snd_seq_get_queue_status(seq, queue, queue_status);
	check_snd("get queue status", err);
	tick = snd_seq_queue_status_get_tick_time(queue_status);

	/* make length of first track the recording length */
	var_value(&tracks[0], tick - tracks[0].last_tick);
	add_byte(&tracks[0], 0xff);
	add_byte(&tracks[0], 0x2f);
	var_value(&tracks[0], 0);

	/* finish other tracks */
	for (i = 1; i < num_tracks; ++i) {
		var_value(&tracks[i], 0);
		add_byte(&tracks[i], 0xff);
		add_byte(&tracks[i], 0x2f);
		var_value(&tracks[i], 0);
	}
}

static void write_file(void)
{
	int used_tracks, time_division, i;
	struct buffer *buf;

	used_tracks = 0;
	for (i = 0; i < num_tracks; ++i)
		used_tracks += !!tracks[i].used;

	/* header id and length */
	fwrite("MThd\0\0\0\6", 1, 8, file);
	/* type 0 or 1 */
	fputc(0, file);
	fputc(used_tracks > 1, file);
	/* number of tracks */
	fputc((used_tracks >> 8) & 0xff, file);
	fputc(used_tracks & 0xff, file);
	/* time division */
	time_division = ticks;
	if (smpte_timing)
		time_division |= (0x100 - frames) << 8;
	fputc(time_division >> 8, file);
	fputc(time_division & 0xff, file);

	for (i = 0; i < num_tracks; ++i) {
		if (!tracks[i].used)
			continue;
		/* track id */
		fwrite("MTrk", 1, 4, file);
		/* data length */
		fputc((tracks[i].size >> 24) & 0xff, file);
		fputc((tracks[i].size >> 16) & 0xff, file);
		fputc((tracks[i].size >> 8) & 0xff, file);
		fputc(tracks[i].size & 0xff, file);
		/* track contents */
		for (buf = &tracks[i].first_buf; buf; buf = buf->next)
			fwrite(buf->buf, 1, buf == tracks[i].cur_buf
			       ? tracks[i].cur_buf_size : BUFFER_SIZE, file);
	}
}

static void list_ports(void)
{
	snd_seq_client_info_t *cinfo;
	snd_seq_port_info_t *pinfo;

	snd_seq_client_info_alloca(&cinfo);
	snd_seq_port_info_alloca(&pinfo);

	puts(" Port    Client name                      Port name");

	snd_seq_client_info_set_client(cinfo, -1);
	while (snd_seq_query_next_client(seq, cinfo) >= 0) {
		int client = snd_seq_client_info_get_client(cinfo);

		if (client == SND_SEQ_CLIENT_SYSTEM)
			continue; /* don't show system timer and announce ports */
		snd_seq_port_info_set_client(pinfo, client);
		snd_seq_port_info_set_port(pinfo, -1);
		while (snd_seq_query_next_port(seq, pinfo) >= 0) {
			/* port must understand MIDI messages */
			if (!(snd_seq_port_info_get_type(pinfo)
			      & SND_SEQ_PORT_TYPE_MIDI_GENERIC))
				continue;
			/* we need both READ and SUBS_READ */
			if ((snd_seq_port_info_get_capability(pinfo)
			     & (SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ))
			    != (SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ))
				continue;
			printf("%3d:%-3d  %-32.32s %s\n",
			       snd_seq_port_info_get_client(pinfo),
			       snd_seq_port_info_get_port(pinfo),
			       snd_seq_client_info_get_name(cinfo),
			       snd_seq_port_info_get_name(pinfo));
		}
	}
}

static void help(const char *argv0)
{
	fprintf(stderr, "Usage: %s [options] outputfile\n"
		"\nAvailable options:\n"
		"  -h,--help                  this help\n"
		"  -V,--version               show version\n"
		"  -l,--list                  list input ports\n"
		"  -p,--port=client:port,...  source port(s)\n"
		"  -b,--bpm=beats             tempo in beats per minute\n"
		"  -f,--fps=frames            resolution in frames per second (SMPTE)\n"
		"  -t,--ticks=ticks           resolution in ticks per beat or frame\n"
		"  -s,--split-channels        create a track for each channel\n"
		"  -m,--metronome=client:port play a metronome signal\n"
		"  -i,--timesig=nn:dd         time signature\n",
		argv0);
}

static void version(void)
{
	fputs("arecordmidi version " SND_UTIL_VERSION_STR "\n", stderr);
}

static void sighandler(int sig)
{
	stop = 1;
}

int main(int argc, char *argv[])
{
	static const char short_options[] = "hVlp:b:f:t:sdm:i:";
	static const struct option long_options[] = {
		{"help", 0, NULL, 'h'},
		{"version", 0, NULL, 'V'},
		{"list", 0, NULL, 'l'},
		{"port", 1, NULL, 'p'},
		{"bpm", 1, NULL, 'b'},
		{"fps", 1, NULL, 'f'},
		{"ticks", 1, NULL, 't'},
		{"split-channels", 0, NULL, 's'},
		{"dump", 0, NULL, 'd'},
		{"metronome", 1, NULL, 'm'},
		{"timesig", 1, NULL, 'i'},
		{ }
	};

	char *filename = NULL;
	int do_list = 0;
	struct pollfd *pfds;
	int npfds;
	int c, err;

	init_seq();

	while ((c = getopt_long(argc, argv, short_options,
				long_options, NULL)) != -1) {
		switch (c) {
		case 'h':
			help(argv[0]);
			return 0;
		case 'V':
			version();
			return 0;
		case 'l':
			do_list = 1;
			break;
		case 'p':
			parse_ports(optarg);
			break;
		case 'b':
			beats = atoi(optarg);
			if (beats < 4 || beats > 6000)
				fatal("Invalid tempo");
			smpte_timing = 0;
			break;
		case 'f':
			frames = atoi(optarg);
			if (frames != 24 && frames != 25 &&
			    frames != 29 && frames != 30)
				fatal("Invalid number of frames/s");
			smpte_timing = 1;
			break;
		case 't':
			ticks = atoi(optarg);
			if (ticks < 1 || ticks > 0x7fff)
				fatal("Invalid number of ticks");
			break;
		case 's':
			channel_split = 1;
			break;
		case 'd':
			fputs("The --dump option isn't supported anymore, use aseqdump instead.\n", stderr);
			break;
		case 'm':
			init_metronome(optarg);
			break;
		case 'i':
			time_signature(optarg);
			break;
		default:
			help(argv[0]);
			return 1;
		}
	}

	if (do_list) {
		list_ports();
		return 0;
	}

	if (port_count < 1) {
		fputs("Pleast specify a source port with --port.\n", stderr);
		return 1;
	}

	if (!ticks)
		ticks = smpte_timing ? 40 : 384;
	if (smpte_timing && ticks > 0xff)
		ticks = 0xff;

	if (optind >= argc) {
		fputs("Please specify a file to record to.\n", stderr);
		return 1;
	}
	filename = argv[optind];

	init_tracks();
	create_queue();
	create_ports();
	connect_ports();
	if (port_count > 1)
		record_port_numbers();

	/* record tempo */
	if (!smpte_timing) {
		int usecs_per_quarter = 60000000 / beats;
		var_value(&tracks[0], 0); /* delta time */
		add_byte(&tracks[0], 0xff);
		add_byte(&tracks[0], 0x51);
		var_value(&tracks[0], 3);
		add_byte(&tracks[0], usecs_per_quarter >> 16);
		add_byte(&tracks[0], usecs_per_quarter >> 8);
		add_byte(&tracks[0], usecs_per_quarter);

		/* time signature */
		var_value(&tracks[0], 0); /* delta time */
		add_byte(&tracks[0], 0xff);
		add_byte(&tracks[0], 0x58);
		var_value(&tracks[0], 4);
		add_byte(&tracks[0], ts_num);
		add_byte(&tracks[0], ts_dd);
		add_byte(&tracks[0], 24); /* MIDI clocks per metronome click */
		add_byte(&tracks[0], 8); /* notated 32nd-notes per MIDI quarter note */
	}
	
	/* always write at least one track */
	tracks[0].used = 1;

	file = fopen(filename, "wb");
	if (!file)
		fatal("Cannot open %s - %s", filename, strerror(errno));

	err = snd_seq_start_queue(seq, queue, NULL);
	check_snd("start queue", err);
	snd_seq_drain_output(seq);

	err = snd_seq_nonblock(seq, 1);
	check_snd("set nonblock mode", err);
	
	if (use_metronome) {
		metronome_set_program();
		metronome_pattern(0);
	}

	signal(SIGINT, sighandler);
	signal(SIGTERM, sighandler);

	npfds = snd_seq_poll_descriptors_count(seq, POLLIN);
	pfds = alloca(sizeof(*pfds) * npfds);
	for (;;) {
		snd_seq_poll_descriptors(seq, pfds, npfds, POLLIN);
		if (poll(pfds, npfds, -1) < 0)
			break;
		do {
			snd_seq_event_t *event;
			err = snd_seq_event_input(seq, &event);
			if (err < 0)
				break;
			if (event)
				record_event(event);
		} while (err > 0);
		if (stop)
			break;
	}

	finish_tracks();
	write_file();

	fclose(file);
	snd_seq_close(seq);
	return 0;
}