feat: support vad for addon.node (#3301)

Co-authored-by: linxiaodong <calm.lin@wukongsch.com>

examples/addon.node/README.md

@@ -1,8 +1,10 @@
-# addon
+# whisper.cpp Node.js addon
 
 This is an addon demo that can **perform whisper model reasoning in `node` and `electron` environments**, based on [cmake-js](https://github.com/cmake-js/cmake-js).
 It can be used as a reference for using the whisper.cpp project in other node projects.
 
+This addon now supports **Voice Activity Detection (VAD)** for improved transcription performance.
+
 ## Install
 
 ```shell
@@ -26,12 +28,88 @@ For Electron addon and cmake-js options, you can see [cmake-js](https://github.c
 
 ## Run
 
+### Basic Usage
+
 ```shell
 cd examples/addon.node
 
 node index.js --language='language' --model='model-path' --fname_inp='file-path'
 ```
 
-Because this is a simple Demo, only the above parameters are set in the node environment.
+### VAD (Voice Activity Detection) Usage
 
-Other parameters can also be specified in the node environment.
+Run the VAD example with performance comparison:
+
+```shell
+node vad-example.js
+```
+
+## Voice Activity Detection (VAD) Support
+
+VAD can significantly improve transcription performance by only processing speech segments, which is especially beneficial for audio files with long periods of silence.
+
+### VAD Model Setup
+
+Before using VAD, download a VAD model:
+
+```shell
+# From the whisper.cpp root directory
+./models/download-vad-model.sh silero-v5.1.2
+```
+
+### VAD Parameters
+
+All VAD parameters are optional and have sensible defaults:
+
+- `vad`: Enable VAD (default: false)
+- `vad_model`: Path to VAD model file (required when VAD enabled)
+- `vad_threshold`: Speech detection threshold 0.0-1.0 (default: 0.5)
+- `vad_min_speech_duration_ms`: Min speech duration in ms (default: 250)
+- `vad_min_silence_duration_ms`: Min silence duration in ms (default: 100)
+- `vad_max_speech_duration_s`: Max speech duration in seconds (default: FLT_MAX)
+- `vad_speech_pad_ms`: Speech padding in ms (default: 30)
+- `vad_samples_overlap`: Sample overlap 0.0-1.0 (default: 0.1)
+
+### JavaScript API Example
+
+```javascript
+const path = require("path");
+const { whisper } = require(path.join(__dirname, "../../build/Release/addon.node"));
+const { promisify } = require("util");
+
+const whisperAsync = promisify(whisper);
+
+// With VAD enabled
+const vadParams = {
+  language: "en",
+  model: path.join(__dirname, "../../models/ggml-base.en.bin"),
+  fname_inp: path.join(__dirname, "../../samples/jfk.wav"),
+  vad: true,
+  vad_model: path.join(__dirname, "../../models/ggml-silero-v5.1.2.bin"),
+  vad_threshold: 0.5,
+  progress_callback: (progress) => console.log(`Progress: ${progress}%`)
+};
+
+whisperAsync(vadParams).then(result => console.log(result));
+```
+
+## Supported Parameters
+
+Both traditional whisper.cpp parameters and new VAD parameters are supported:
+
+- `language`: Language code (e.g., "en", "es", "fr")
+- `model`: Path to whisper model file
+- `fname_inp`: Path to input audio file
+- `use_gpu`: Enable GPU acceleration (default: true)
+- `flash_attn`: Enable flash attention (default: false)
+- `no_prints`: Disable console output (default: false)
+- `no_timestamps`: Disable timestamps (default: false)
+- `detect_language`: Auto-detect language (default: false)
+- `audio_ctx`: Audio context size (default: 0)
+- `max_len`: Maximum segment length (default: 0)
+- `max_context`: Maximum context size (default: -1)
+- `prompt`: Initial prompt for decoder
+- `comma_in_time`: Use comma in timestamps (default: true)
+- `print_progress`: Print progress info (default: false)
+- `progress_callback`: Progress callback function
+- VAD parameters (see above section)