OSC Syntax of oscpkt

D300

Hey,

i´m trying to understand the OSC syntax of the osc library ( http://gruntthepeon.free.fr/oscpkt/html/index.html) on a ASCII String / HEX level to create a parser for another environment which cant have a OSC lib right now.
for testing I have the app, Packet Sender ( https://packetsender.com/ ) and as comparison;´: when receiving data from MAX CNMAT a ASCII string looks like this eg.:

#bundle\00\00\00\00\00\00\00\00\01\00\00\00\0c/voices\00,\00\00\00

right now I cant receive anything from Bela in the local PacketSender app.
so far PacketSender was the most reliable network monitor software to me.

it should be easy. is there anything I´m missing or do you know another way for finding out the osc syntax of the oscpkt lib?

#include <Bela.h>
#include <libraries/OscSender/OscSender.h>
#include <libraries/OscReceiver/OscReceiver.h>

OscReceiver oscReceiver;
OscSender oscSender;

int localPort = 7562;

const char* remoteIp = "192.168.2.125"; //
int remotePort = 51909; // this port is shown by PacketSender

// parse messages received by the OSC receiver
// msg is Message class of oscpkt: http://gruntthepeon.free.fr/oscpkt/

void on_receive(oscpkt::Message* msg, const char* addr, void* arg)
{
	printf("From %s\n", addr);
	if(msg->match("/voices"))
	{
		//int intArg;
		//float floatArg;
		//printf("received a message with int %i and float %f\n", intArg, floatArg);
	}
}

bool setup(BelaContext *context, void *userData)
{
	oscReceiver.setup(localPort, on_receive);
	oscSender.setup(remotePort, remoteIp);
	
	// test message
	oscSender.newMessage("/osc-acknowledge").add(4.2f).add(std::string("OSC message received")).send();

	return true;
}

void render(BelaContext *context, void *userData)
{
	// test message
	oscSender.newMessage("/osc-acknowledge").add(4.2f).add(std::string("OSC message received")).send();
}

void cleanup(BelaContext *context, void *userData)
{

}

giuliomoro

D300 const char* remoteIp = "192.168.2.125"; //

what is this IP? Is it on a network that Bela has access to? Would you mind describing the topology of your network, including the devices that are on it and what software is running on each?

D300

giuliomoro what is this IP?

this IP is from my macbook pro ( 2017 ), with macos Catalina. on this macbook runs PacketSender.app
in the moment i tested this, max msp was also running on the MBP2017. could it be that it blocked the port?

The BELA is attached to the MBP via USB. on the BELA runs the code posted above.

giuliomoro

right, so that may be the IP address of the macbook on a different network (e.g.: wifi, or ethernet), but Bela has no access to those: Bela is on a network with your macbook that has Bela on 192.168.7.2 and the macbook on 192.168.7.1 . So you should use

const char* remoteIp = "192.168.7.1";

and then some messages should start coming through.

D300

giuliomoro thanks for the fast reply. dude you are rocking this forum! love to work with bela <3

D300

Hey,
i´m digging deeper in the osc syntax and i´m wondering: eg. this string:
"/snd1-play, playState 1, volume 0.8"

/snd1-play\00\00,if\00\00\00\00\01?L\cc\cd

why the value of 0.8f is written in hex?

another question with this string:
/snd1-play, playState 1, volume 1.0
/snd-1-play\00\00,if\00\00\00\00\01?\80\00\00

0x80 = 128, is this the maximum value for the volume?
is the value ranged like a midi value?

giuliomoro

Can you show your code?

D300

giuliomoro what i´m doing is ... I´m sending osc messages to packetSender.app ( https://packetsender.com/ ) to monitor the osc syntax

this is the code in the render function

	for(unsigned int n = 0; n < context->audioFrames; n++)
	{
		if (count >= context->audioSampleRate && pingpong == false )
		{
			oscSender.newMessage("/snd1-play").add(1).add(1.0f).send();
			
			pingpong = true;
			count = 0;
		}
		else if (count >= context->audioSampleRate && pingpong == true )
		{
			oscSender.newMessage("/snd1-play").add(0).add(1.0f).send();
			
			pingpong = false;
			count = 0;
		}
		count++;
	}

my situation is that my client cannot integrate the osc library and only send strings via udp in the length of 90 bytes. thus I´m looking for a logic to be compatible with the osc lib syntax when sending strings via udp.

giuliomoro

D300 my situation is that my client cannot integrate the osc library and only send strings via udp in the length of 90 bytes.

What's your client? Why can it not use a osc library (oscpkt or other)? Why is the length fixed to 90? Does it have to be a string (i.e.: terminated by a null character)?

D300 as said, i need the 90 bytes message length, which shall be filled up with spaces (0x20). can you give me a hint where i could modify the osc lib to filter out all spaces?

What does it mean that it shall be filled up with spaces but have to filter out the spaces?

giuliomoro

/snd1-play\00\00,if\00\00\00\00\01?L\cc\cd

Where do you get these printouts from? If you were to print them as hex bytes alongside the string representation, it would be perhaps easier to parse them.
See the OSC packet specifications https://opensoundcontrol.stanford.edu/spec-1_0.html and keep in mind that floating point numbers are represented as IEEE754 single-precision https://www.h-schmidt.net/FloatConverter/IEEE754.html , so 1.0 is made up of the 0x3f, 0x80, 0x00 and 0x00 bytes.

D300

giuliomoro Where do you get these printouts from?

packetSender app. i also get the hex string.

as said, i need the 90 bytes message length, which shall be filled up with spaces (0x20). can you give me a hint where i could modify the osc lib to filter out all spaces?

D300

giuliomoro hey, i made an own little protocoll and now the boards are exchanging via UDP and it works 🙂