Add prebuilt C++ shared library SDK (libopenwakeword_ax) + header for secondary development

- cpp/lib/ax650|ax630c/libopenwakeword_ax.so: prebuilt shared libraries
- cpp/include/openwakeword_ax.hpp: public API (WakeWordDetector::ProcessFrame)
- cpp/README.md: shared-library usage section
- README.md: 二次开发 section with link snippet

README.md

@@ -108,6 +108,28 @@ THRESHOLD=0.5 bash cpp/run_batch_openwakeword_ax630c.sh  # AX630C
 结果分别写入 `outputs/cpp_ax650_batch/` 和 `outputs/cpp_ax630c_batch/`。
 详细 C++ 说明见 `cpp/README.md`。
 
+### 共享库（二次开发）
+
+```text
+cpp/lib/ax650/libopenwakeword_ax.so      # AX650 共享库
+cpp/lib/ax630c/libopenwakeword_ax.so     # AX630C 共享库
+cpp/include/openwakeword_ax.hpp          # 公共 API 头文件
+```
+
+```cpp
+#include "openwakeword_ax.hpp"
+
+openwakeword::WakeWordDetector detector(
+    "models/650",                                 // axmodel 目录
+    "config/openwakeword_mel_weights.bin",        // CPU mel 权重
+    0.5f);                                        // 阈值
+openwakeword::FrameResult result = detector.ProcessFrame(pcm_frame); // 1280 samples
+// result.names / result.max_scores / result.any_triggered
+```
+
+板端运行时需提供 BSP 动态库路径（AX650 通常为 `/soc/lib`，AX630C 为
+`/opt/lib`）。共享库源码与构建脚本在 GitHub 仓库。
+
 ## 参考
 
 - [openWakeWord](https://github.com/dscripka/openWakeWord)

cpp/README.md

@@ -88,9 +88,49 @@ THRESHOLD=0.6 AUDIO=audio/openwakeword/hey_mycroft_test.wav \
 bash cpp/run_openwakeword_ax630c.sh
 ```
 
-## 源码
+## 二次开发（共享库）
 
-C++ 源码、构建脚本与 BSP 下载脚本在 GitHub 仓库：
-https://github.com/AXERA-TECH/openWakeWord.AXERA
-（HuggingFace 仅发布预编译二进制。）
+编译产物除可执行文件外，还包含共享库：
 
+```text
+cpp/lib/ax650/libopenwakeword_ax.so      # AX650
+cpp/lib/ax630c/libopenwakeword_ax.so     # AX630C
+cpp/include/openwakeword_ax.hpp          # 公共 API 头文件
+```
+
+在自己的 CMake 工程中链接：
+
+```cmake
+add_library(openwakeword_ax SHARED IMPORTED)
+set_target_properties(openwakeword_ax PROPERTIES
+  IMPORTED_LOCATION "${CMAKE_CURRENT_SOURCE_DIR}/cpp/lib/ax650/libopenwakeword_ax.so")
+target_include_directories(your_app PRIVATE cpp/include)
+target_link_libraries(your_app PRIVATE openwakeword_ax)
+```
+
+最小使用示例：
+
+```cpp
+#include "openwakeword_ax.hpp"
+
+openwakeword::WakeWordDetector detector(
+    "models/650",                    // axmodel 目录
+    "config/openwakeword_mel_weights.bin",  // CPU mel 权重
+    0.5f);                            // 阈值
+
+// 每 80ms 喂一帧 1280 个 int16 样本（16 kHz）
+openwakeword::FrameResult result = detector.ProcessFrame(pcm_frame);
+for (std::size_t i = 0; i < result.names.size(); ++i) {
+    printf("%s max_score=%.4f\n", result.names[i].c_str(),
+           result.max_scores[i]);
+}
+if (result.any_triggered) { /* 唤醒 */ }
+detector.Reset();  // 新会话时清空流式状态
+```
+
+板端运行时需提供 BSP 动态库路径（AX650 通常为 `/soc/lib`，AX630C 为
+`/opt/lib`）：
+
+```bash
+export LD_LIBRARY_PATH=/soc/lib:${LD_LIBRARY_PATH}
+```

cpp/include/openwakeword_ax.hpp

@@ -0,0 +1,45 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+namespace openwakeword {
+
+// 单帧（80ms）推理结果：6 个官方唤醒词的逐类 logits 与汇总。
+struct FrameResult {
+    std::vector<std::string> names;            // 分类器名（alexa_v0.1 ...）
+    std::vector<std::vector<float>> logits;    // 每个分类器的逐类 logit
+    std::vector<float> max_scores;             // 每个分类器的最大 logit
+    bool any_triggered = false;                // 任一 max_score > threshold
+};
+
+// 流式唤醒词检测器：mel 在 CPU 计算，embedding + 6 个分类器在 NPU 执行。
+class WakeWordDetector {
+public:
+    // models_dir：包含 openwakeword__*.axmodel 的目录（models/650 或 models/630C）
+    // mel_weights：openwakeword_mel_weights.bin（CPU mel 权重）
+    WakeWordDetector(const std::string& models_dir,
+                     const std::string& mel_weights,
+                     float threshold = 0.5f);
+    ~WakeWordDetector();
+
+    WakeWordDetector(const WakeWordDetector&) = delete;
+    WakeWordDetector& operator=(const WakeWordDetector&) = delete;
+
+    // 清空流式状态（新会话/断句后调用）
+    void Reset();
+
+    // 处理一帧 1280 个 int16 样本（80ms @16kHz），返回 6 个分类器的得分。
+    // 前 5 帧为预热窗口（返回 0），与 openwakeword 官方行为一致。
+    FrameResult ProcessFrame(const int16_t* samples);
+
+    float threshold() const { return threshold_; }
+
+private:
+    struct Impl;
+    Impl* impl_;
+    float threshold_;
+};
+
+}  // namespace openwakeword

cpp/lib/ax630c/libopenwakeword_ax.so

@@ -0,0 +1 @@
+libopenwakeword_ax.so.0

cpp/lib/ax630c/libopenwakeword_ax.so.0

@@ -0,0 +1 @@
+libopenwakeword_ax.so.0.1.0

cpp/lib/ax650/libopenwakeword_ax.so

@@ -0,0 +1 @@
+libopenwakeword_ax.so.0

cpp/lib/ax650/libopenwakeword_ax.so.0

@@ -0,0 +1 @@
+libopenwakeword_ax.so.0.1.0