Added functions to detect SysEx packets

CHANGELOG.md

@@ -22,6 +22,9 @@ This release focuses on:
 - `UsbMidiEventPacket::as_raw_bytes` function.
 - `UsbMidiEventPacket::to_raw_bytes` function.
 - `UsbMidiEventPacket::try_from_payload_bytes` function.
+- `UsbMidiEventPacket::is_sysex` function.
+- `UsbMidiEventPacket::is_sysex_start` function.
+- `UsbMidiEventPacket::is_sysex_end` function.
 - `TryFrom<&UsbMidiEventPacket>` implementation for `Message` type.
 - `Message::into_packet` function.
 - `Message::code_index_number` function.

examples/example-esp32s3/Cargo.toml

@@ -14,3 +14,4 @@ esp-println = { version = "0.12.0", features = ["esp32s3", "log"] }
 usb-device = { version = "0.3.2", features = ["control-buffer-256"] }
 usbd-midi = { path = "../../" }
 midi-convert = "0.2.0"
+heapless = "0.8.0"

examples/example-esp32s3/src/main.rs

@@ -8,6 +8,7 @@ use core::ptr::addr_of_mut;
 use esp_backtrace as _;
 use esp_hal::{clock, gpio, otg_fs, xtensa_lx_rt, Config};
 use esp_println::println;
+use heapless::Vec;
 use midi_convert::midi_types::{Channel, MidiMessage, Note, Value7};
 use midi_convert::{parse::MidiTryParseSlice, render_slice::MidiRenderSlice};
 use usb_device::prelude::*;
@@ -41,17 +42,41 @@ fn main() -> ! {
     let button = gpio::Input::new(peripherals.GPIO0, gpio::Pull::Up);
     let mut last_button_level = button.level();
 
+    let mut sysex_buffer = Vec::<u8, 64>::new();
+
     loop {
         if usb_dev.poll(&mut [&mut midi_class]) {
             // Receive messages.
             let mut buffer = [0; 64];
 
             if let Ok(size) = midi_class.read(&mut buffer) {
                 let buffer_reader = MidiPacketBufferReader::new(&buffer, size);
-                for packet in buffer_reader.into_iter() {
-                    if let Ok(packet) = packet {
+                for packet in buffer_reader.into_iter().flatten() {
+                    if !packet.is_sysex() {
                         let message = MidiMessage::try_parse_slice(packet.payload_bytes());
-                        println!("Cable: {:?}, Message: {:?}", packet.cable_number(), message);
+                        println!(
+                            "Regular Message, cable: {:?}, message: {:?}",
+                            packet.cable_number(),
+                            message
+                        );
+                    } else {
+                        if packet.is_sysex_start() {
+                            println!("SysEx message start");
+                            sysex_buffer.clear();
+                        }
+
+                        match sysex_buffer.extend_from_slice(packet.payload_bytes()) {
+                            Ok(_) => {
+                                if packet.is_sysex_end() {
+                                    println!("SysEx message end");
+                                    println!("Buffered SysEx message: {:?}", sysex_buffer);
+                                }
+                            }
+                            Err(_) => {
+                                println!("SysEx buffer overflow.");
+                                break;
+                            }
+                        }
                     }
                 }
             }

src/packet/mod.rs

@@ -115,4 +115,30 @@ impl UsbMidiEventPacket {
 
         Ok(Self { raw })
     }
+
+    /// Returns if the packet payload is part of a SysEx message.
+    pub fn is_sysex(&self) -> bool {
+        let Ok(cin) = CodeIndexNumber::try_from(self.raw[0] & 0x0F) else {
+            return false;
+        };
+
+        match cin {
+            CodeIndexNumber::SysexStartsOrContinues
+            | CodeIndexNumber::SysexEnds2Bytes
+            | CodeIndexNumber::SysexEnds3Bytes => true,
+            CodeIndexNumber::SystemCommon1Byte => self.raw[1] == 0xF7,
+            CodeIndexNumber::SingleByte => self.raw[1] < 0x80,
+            _ => false,
+        }
+    }
+
+    /// Returns if the packet payload contains the start of a SysEx message.
+    pub fn is_sysex_start(&self) -> bool {
+        self.is_sysex() && self.raw[1] == 0xF0
+    }
+
+    /// Returns if the packet payload contains the end of a SysEx message.
+    pub fn is_sysex_end(&self) -> bool {
+        self.is_sysex() && (self.raw[1] == 0xF7 || self.raw[2] == 0xF7 || self.raw[3] == 0xF7)
+    }
 }