Diff: MIDIparser.cpp

Revision:

0:69cbdcd5d770

Child:

1:1c3f0c6ea0fb

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MIDIparser.cpp	Wed Aug 03 16:22:22 2016 +0000
@@ -0,0 +1,144 @@
+/**
+ * @file    MIDIparser.cpp
+ * @brief   MIDI parser - converts bytes into queued MIDI messages
+ * @author  Patrick Thomas
+ * @version 1.0
+ * @see     
+ *
+ * Copyright (c) 2016
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "MIDIparser.h"
+
+MIDIparser::MIDIparser() {
+
+}
+
+void MIDIparser::parse(uint8_t this_byte) {
+
+    // Data byte
+    if (this_byte < 128) {
+
+        // We expect the output buffer to be non-empty here
+        if (input_vector.available()) {
+
+            input_vector.put(this_byte);
+
+            // Dual condition - perform one more read after this
+            if (!sysex && dual) dual = false;
+
+            // Single condition - send two bytes now
+            else if (!sysex && !dual) {
+
+                output_queue.push(MIDIMessage(input_vector.head(), input_vector.size()));
+                input_vector.clear();
+            }
+        }
+    }
+
+    // System realtime byte
+    else if (this_byte > 243) {
+
+        switch (this_byte & 0xF) {
+
+        // Undefined
+        case 4:
+        case 5:
+            break;
+
+            // Sysex end
+        case 7:
+            // Only output valid Sysex data
+            if (sysex && !dual) output_queue.push(MIDIMessage(input_vector.head(), input_vector.size()));
+            input_vector.clear();
+            break;
+
+            // Realtime
+        default:
+            output_queue.push(MIDIMessage(&this_byte, 1));
+            break;
+        }
+    }
+
+    // Status byte
+    else {
+
+        // We expect the output buffer to be empty here
+        if (!input_vector.available()) {
+
+            input_vector.put(this_byte);
+
+            // Set flags
+            switch ((this_byte >> 4) & 7) {
+            case 0:
+            case 1:
+            case 2:
+            case 3:
+            case 6:
+                sysex = false;
+                dual = true;
+                break;
+
+            case 4:
+            case 5:
+                sysex = false;
+                dual = false;
+                break;
+
+            case 7:
+                switch (this_byte & 7) {
+                case 0:
+                    sysex = true;
+                    dual = false;
+                    break;
+
+                case 1:
+                case 3:
+                    sysex = false;
+                    dual = false;
+                    break;
+
+                case 2:
+                    sysex = false;
+                    dual = true;
+                    break;
+
+                default:
+                    break;
+                }
+                break;
+
+                default:
+                    break;
+            }
+        }
+
+        // Invalidate the output buffer by setting flags
+        else {
+            sysex = true;
+            dual = true;
+        }
+    }
+}
+
+bool MIDIparser::available() { return !output_queue.empty(); }
+
+MIDIMessage MIDIparser::grab() {
+
+    MIDIMessage output;
+    output = output_queue.front();
+    output_queue.pop();
+    return output;
+}