[remote_base] Add zero-copy packed sint32 decoder for #12985 (#13093)

esphome/components/remote_base/remote_base.cpp

@@ -128,6 +128,39 @@ void RemoteReceiverBase::call_dumpers_() {
 
 void RemoteReceiverBinarySensorBase::dump_config() { LOG_BINARY_SENSOR("", "Remote Receiver Binary Sensor", this); }
 
+/* RemoteTransmitData */
+
+void RemoteTransmitData::set_data_from_packed_sint32(const uint8_t *data, size_t len, size_t count) {
+  this->data_.clear();
+  this->data_.reserve(count);
+
+  while (len > 0) {
+    // Parse varint (inline, no dependency on api component)
+    uint32_t raw = 0;
+    uint32_t shift = 0;
+    uint32_t consumed = 0;
+    for (; consumed < len && consumed < 5; consumed++) {
+      uint8_t byte = data[consumed];
+      raw |= (byte & 0x7F) << shift;
+      if ((byte & 0x80) == 0) {
+        consumed++;
+        break;
+      }
+      shift += 7;
+    }
+    if (consumed == 0)
+      break;  // Parse error
+
+    // Zigzag decode: (n >> 1) ^ -(n & 1)
+    int32_t decoded = static_cast<int32_t>((raw >> 1) ^ (~(raw & 1) + 1));
+    this->data_.push_back(decoded);
+    data += consumed;
+    len -= consumed;
+  }
+}
+
+/* RemoteTransmitterBase */
+
 void RemoteTransmitterBase::send_(uint32_t send_times, uint32_t send_wait) {
 #ifdef ESPHOME_LOG_HAS_VERY_VERBOSE
   const auto &vec = this->temp_.get_data();

esphome/components/remote_base/remote_base.h

@@ -31,6 +31,11 @@ class RemoteTransmitData {
   uint32_t get_carrier_frequency() const { return this->carrier_frequency_; }
   const RawTimings &get_data() const { return this->data_; }
   void set_data(const RawTimings &data) { this->data_ = data; }
+  /// Set data from packed protobuf sint32 buffer (zigzag + varint encoded)
+  /// @param data Pointer to packed zigzag-varint-encoded sint32 values
+  /// @param len Length of the buffer in bytes
+  /// @param count Number of values (for reserve optimization)
+  void set_data_from_packed_sint32(const uint8_t *data, size_t len, size_t count);
   void reset() {
     this->data_.clear();
     this->carrier_frequency_ = 0;