Abir DeolandDaniel Bevenius
d5d6e59bfa
* docs(stream): clarify VAD mode timestamps and CWD model path errors AI use: I found this while building against the library and used an AI assistant to help verify the relevant source (file/line refs above). The report and the documentation wording are mine, and I've checked every claim against the source myself. * Update examples/stream/README.md Co-authored-by: Daniel Bevenius <daniel.bevenius@gmail.com> --------- Co-authored-by: Daniel Bevenius <daniel.bevenius@gmail.com>
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 continuously.
More info is available in issue #10.
./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:
./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.
Output format
The output format depends on --step, and there is no flag to override it.
Default (--step > 0): one rolling segment, no timestamps, rewritten in place with ANSI erase-line escapes. Fine for a terminal, wrong for a pipe.
VAD mode (--step 0): timestamped blocks meant for parsing.
### Transcription 0 START | t0 = 0 ms | t1 = 4000 ms
[00:00:00.000 --> 00:00:03.480] Hello there.
### Transcription 0 END
- timestamps are enabled implicitly by --step 0; there is no -nt here
- strip the [t0 --> t1] prefix; don't discard those lines as log noise
- -tdrz appends [SPEAKER_TURN] on a speaker change
- the ### markers and [Start speaking] are on stdout
Model path
-m is relative to the process CWD and defaults to models/ggml-base.en.bin. Spawning whisper-stream from a parent with a different CWD needs an absolute path, or you get:
error: failed to initialize whisper context
which is also what a corrupt model prints, so check the path first.
Building
The whisper-stream tool depends on SDL2 library to capture audio from the microphone. You can build it like this:
# 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