feat(engine): 优化字幕引擎输出格式、准备合并两个字幕引擎

- 重构字幕引擎相关代码
- 准备合并两个字幕引擎

engine/audio2text/vosk.py

@@ -0,0 +1,59 @@
+import json
+from datetime import datetime
+
+from vosk import Model, KaldiRecognizer, SetLogLevel
+from utils import stdout_obj
+
+class VoskRecognizer:
+    """
+    使用 Vosk 引擎流式处理的音频数据，并在标准输出中输出与 Auto Caption 软件可读取的 JSON 字符串数据
+
+    初始化参数：
+        model_path: Vosk 识别模型路径
+    """
+    def __int__(self, model_path: str):
+        SetLogLevel(-1)
+        if model_path.startswith('"'):
+            model_path = model_path[1:]
+        if model_path.endswith('"'):
+            model_path = model_path[:-1]
+        self.model_path = model_path
+        self.time_str = ''
+        self.cur_id = 0
+        self.prev_content = ''
+
+        self.model = Model(self.model_path)
+        self.recognizer = KaldiRecognizer(self.model, 16000)
+    
+    def send_audio_frame(self, data: bytes):
+        """
+        发送音频帧给 Vosk 引擎，引擎将自动识别并将识别结果输出到标准输出中
+
+        Args:
+            data: 音频帧数据，采样率必须为 16000Hz
+        """
+        caption = {}
+        caption['command'] = 'caption'
+        caption['translation'] = ''
+
+        if self.recognizer.AcceptWaveform(data):
+            content = json.loads(self.recognizer.Result()).get('text', '')
+            caption['index'] = self.cur_id
+            caption['text'] = content
+            caption['time_s'] = self.time_str
+            caption['time_t'] = datetime.now().strftime('%H:%M:%S.%f')[:-3]
+            self.prev_content = ''
+            self.cur_id += 1
+        else:
+            content = json.loads(self.recognizer.PartialResult()).get('partial', '')
+            if content == '' or content == self.prev_content:
+                return
+            if self.prev_content == '':
+                self.time_str = datetime.now().strftime('%H:%M:%S.%f')[:-3]
+            caption['index'] = self.cur_id
+            caption['text'] = content
+            caption['time_s'] = self.time_str
+            caption['time_t'] = datetime.now().strftime('%H:%M:%S.%f')[:-3]
+            self.prev_content = content
+        
+        stdout_obj(caption)