Beginning of code for the RSPduo + bugfix for the hackrf

core/src/dsp/utils/bitstream.h

@@ -0,0 +1,43 @@
+#pragma once
+
+namespace dsp {
+    inline uint64_t readBits(int offset, int length, uint8_t* buffer) {
+        uint64_t outputValue = 0;
+        
+        int lastBit = offset + (length - 1);
+
+        int firstWord = offset / 8;
+        int lastWord = lastBit / 8;
+        int firstOffset = offset - (firstWord * 8);
+        int lastOffset = lastBit - (lastWord * 8);
+
+        int wordCount = (lastWord - firstWord) + 1;
+
+        // If the data fits in a single byte, just get it
+        if (wordCount == 1) {
+            return (buffer[firstWord] & (0xFF >> firstOffset)) >> (7 - lastOffset);
+        }
+
+        int bitsRead = length;
+        for (int i = 0; i < wordCount; i++) {
+            // First word
+            if (i == 0) {
+                bitsRead -= 8 - firstOffset;
+                outputValue |= (uint64_t)(buffer[firstWord] & (0xFF >> firstOffset)) << bitsRead;
+                continue;
+            }
+
+            // Last word
+            if (i == (wordCount - 1)) {
+                outputValue |= (uint64_t)buffer[lastWord] >> (7 - lastOffset);
+                break;
+            }
+
+            // Just a normal byte
+            bitsRead -= 8;
+            outputValue |= (uint64_t)buffer[firstWord + i] << bitsRead;
+        }
+
+        return outputValue;
+    }
+}