Midi controller for Ecasound

Justin Rosander <[email protected]> Wed, 13 Feb 2013 03:12:03 -0500

Newsgroups	gmane.comp.audio.ecasound.general
Message-ID	<CAOxgbvP1cw7nLqkW0SFCRKJfjW6EZeDauEUcuksGc+AJ4mCV6w@mail.gmail.com>

Hi there,
not sure if this would be an appropriate channel for this, but I am
currently writing a midi controller for the purpose of controlling ecasound
effects in real-time using a GUI.  It is working, but I am running into a
bit of a problem getting ecasound to connect to it automatically without
using aconnect.  I am using Elementary as the widget set from E17 (
enlightenment.org), and have attached the source code to this email.  It
can be built as follows:
gcc main.c -o slider -lasound `pkg-config elementary --cflags --libs`
It currently just sends CC events to channel 1, controller 1.

I am using the following ecasound command:

ecasound -i test.wav -o alsahw -ea:100 -km:1,1,200,1,1
-Md:alsaseq,midicontroller

I am grateful for any thoughts on what I am doing wrong in my code.

Justin

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main.c (text/x-csrc, 2.2 KB)

#include <Elementary.h>
#include <alsa/asoundlib.h>

static snd_seq_t *seq_handle;
static int out_port;

void midi_open(void)
{
    snd_seq_open(&seq_handle, "default", SND_SEQ_OPEN_OUTPUT, 0);

    snd_seq_set_client_name(seq_handle, "midcontroller");
    out_port = snd_seq_create_simple_port(seq_handle, "out",
                      SND_SEQ_PORT_CAP_READ|SND_SEQ_PORT_CAP_SUBS_READ,
                      SND_SEQ_PORT_TYPE_APPLICATION);
}



static void
on_done(void *data, Evas_Object *obj, void *event_info)
{
	// quit the mainloop (elm_run function will return)
	elm_exit();
}

static void
_changed_cb(void *data, Evas_Object *obj, void *event_info)
{
    double val = elm_slider_value_get(obj);
	snd_seq_event_t ev;
	snd_seq_ev_clear(&ev);
	snd_seq_ev_set_source(&ev, out_port);
	snd_seq_ev_set_subs(&ev);
	
	snd_seq_ev_set_controller(&ev, 1, 1, (int)val);
     snd_seq_ev_set_direct(&ev);
	snd_seq_event_output_direct(seq_handle, &ev);
	snd_seq_drain_output(seq_handle);
}


EAPI_MAIN int
elm_main(int argc, char **argv)
{

	midi_open();

	Evas_Object *win, *box, *sl;

	win = elm_win_util_standard_add("slider", "Slider");
	evas_object_smart_callback_add(win, "delete,request", on_done, NULL);
	

	box = elm_box_add(win);
	elm_box_horizontal_set(box, EINA_TRUE);
	elm_win_resize_object_add(win, box);
	evas_object_show(box);

	//add slider
	sl = elm_slider_add(win);
	elm_slider_horizontal_set(sl, EINA_FALSE);
	//set default text
	elm_object_text_set(sl, "Slide me");
	evas_object_size_hint_align_set(sl, EVAS_HINT_FILL, 0.5);
	evas_object_size_hint_weight_set(sl, EVAS_HINT_EXPAND, EVAS_HINT_EXPAND);
	//set initial value
	elm_slider_value_set(sl, 0.0);
	//span size of slider
	elm_slider_span_size_set(sl, 200);
	//show units label
	elm_slider_unit_format_set(sl, "%1.0f units");
	//min and max values
	elm_slider_min_max_set(sl, 0, 127);
	//show value on the slider knob
	elm_slider_indicator_format_set(sl, "%1.0f");
	//invert
	elm_slider_inverted_set(sl, EINA_TRUE);
	//pack at the end of the box
	elm_box_pack_end(box, sl);
	evas_object_show(sl);
	//callback to function returning value

	evas_object_smart_callback_add(sl, "changed", _changed_cb, NULL);
	evas_object_show(win);

	elm_run();
	elm_shutdown();
	return 0;

}
ELM_MAIN()