examples : update vad support in stream example [no ci]

Author: danbev

examples/stream/README.md

@@ -1,51 +1,41 @@
-# whisper.cpp/examples/stream
-
-This is a naive example of performing real-time inference on audio from your microphone.
-The `whisper-stream` tool samples the audio every half a second and runs the transcription continously.
-More info is available in [issue #10](https://github.com/ggerganov/whisper.cpp/issues/10).
-
-```bash
-./build/bin/whisper-stream -m ./models/ggml-base.en.bin -t 8 --step 500 --length 5000
-```
-
-https://user-images.githubusercontent.com/1991296/194935793-76afede7-cfa8-48d8-a80f-28ba83be7d09.mp4
-
-## Sliding window mode with VAD
-
-Setting the `--step` argument to `0` enables the sliding window mode:
-
-```bash
- ./build/bin/whisper-stream -m ./models/ggml-base.en.bin -t 6 --step 0 --length 30000 -vth 0.6
-```
-
-In this mode, the tool will transcribe only after some speech activity is detected. A very
-basic VAD detector is used, but in theory a more sophisticated approach can be added. The
-`-vth` argument determines the VAD threshold - higher values will make it detect silence more often.
-It's best to tune it to the specific use case, but a value around `0.6` should be OK in general.
-When silence is detected, it will transcribe the last `--length` milliseconds of audio and output
-a transcription block that is suitable for parsing.
-
-## Building
-
-The `whisper-stream` tool depends on SDL2 library to capture audio from the microphone. You can build it like this:
-
-```bash
-# Install SDL2
-# On Debian based linux distributions:
-sudo apt-get install libsdl2-dev
-
-# On Fedora Linux:
-sudo dnf install SDL2 SDL2-devel
-
-# Install SDL2 on Mac OS
-brew install sdl2
-
-cmake -B build -DWHISPER_SDL2=ON
-cmake --build build --config Release
-
-./build/bin/whisper-stream
-```
-
-## Web version
-
-This tool can also run in the browser: [examples/stream.wasm](/examples/stream.wasm)
+# whisper.cpp/examples/stream
+
+This is a naive example of performing real-time inference on audio from your microphone.
+The `whisper-stream` tool samples the audio every half a second and runs the transcription continously.
+More info is available in [issue #10](https://github.com/ggerganov/whisper.cpp/issues/10).
+
+```bash
+./build/bin/whisper-stream -m ./models/ggml-base.en.bin -t 8 --step 500 --length 5000
+```
+
+https://user-images.githubusercontent.com/1991296/194935793-76afede7-cfa8-48d8-a80f-28ba83be7d09.mp4
+
+## VAD support
+
+VAD support can be enabled by specifying the `--vad` and optionally a `--vad-model` (by default
+`models/for-tests-silero-v5.1.2-ggml.bin` will be used).
+
+## Building
+
+The `whisper-stream` tool depends on SDL2 library to capture audio from the microphone. You can build it like this:
+
+```bash
+# Install SDL2
+# On Debian based linux distributions:
+sudo apt-get install libsdl2-dev
+
+# On Fedora Linux:
+sudo dnf install SDL2 SDL2-devel
+
+# Install SDL2 on Mac OS
+brew install sdl2
+
+cmake -B build -DWHISPER_SDL2=ON
+cmake --build build --config Release
+
+./build/bin/whisper-stream
+```
+
+## Web version
+
+This tool can also run in the browser: [examples/stream.wasm](/examples/stream.wasm)