DeepSpeech-examples/vad_transcriber/README.md

## Transcribing longer audio clips

The Command and GUI tools perform transcription on long wav files.
They take in a wav file of any duration, use the WebRTC Voice Activity Detector (VAD)
to split it into smaller chunks and finally save a consolidated transcript.

### 0. Prerequisites
#### 0.1 Install requiered packages
Install the package which contains rec on the machine:

Fedora:

``` sudo dnf install sox ```

Tested on: 29

Ubuntu/Debian

``` sudo apt install sox ```

A list of distributions where the package is available can be found at: https://pkgs.org/download/sox

#### 0.1 Download Deepspeech 
Either clone from git via git clone, or Download a version from the release page

For the next steps we assume you have extracted the files to `~/Deepspeech`


#### 0.2 Setup your environment

Ubuntu/Debian:

```
~/Deepspeech$ sudo apt install virtualenv
~/Deepspeech$ cd examples/vad_transcriber
~/Deepspeech/examples/vad_transcriber$ virtualenv -p python3 venv
~/Deepspeech/examples/vad_transcriber$ source venv/bin/activate
(venv) ~/Deepspeech/examples/vad_transcriber$ pip3 install -r requirements.txt
```

Fedora

```
~/Deepspeech$ sudo dnf install python-virtualenv
~/Deepspeech$ cd examples/vad_transcriber
~/Deepspeech/examples/vad_transcriber$ virtualenv -p python3 venv
~/Deepspeech/examples/vad_transcriber$ source venv/bin/activate
(venv) ~/Deepspeech/examples/vad_transcriber$ pip3 install -r requirements.txt
```

Tested on: 29

### 1. Command line tool

The command line tool processes a wav file of any duration and returns a trancript
which will the saved in the same directory as the input audio file.

The command line tool gives you control over the aggressiveness of the VAD.
Set the aggressiveness mode, to an integer between 0 and 3.
0 being the least aggressive about filtering out non-speech, 3 is the most aggressive.

```
(venv) ~/Deepspeech/examples/vad_transcriber
$ python3 audioTranscript_cmd.py --aggressive 1 --audio ./audio/guido-van-rossum.wav --model ./models/0.4.1/


Filename                       Duration(s)          Inference Time(s)    Model Load Time(s)   Scorer Load Time(s)
sample_rec.wav                 13.710               20.797               5.593                17.742

```

**Note:** Only `wav` files with a 16kHz sample rate are supported for now, you can convert your files to the appropriate format with ffmpeg if available on your system.

    ffmpeg -i infile.mp3  -ar 16000 -ac 1  outfile.wav

### 2. Minimalistic GUI

The GUI tool does the same job as the CLI tool. The VAD is fixed at an aggressiveness of 1.
The output is displayed in the transcription window and saved into the directory as the input
audio file as well.

```
(venv) ~/Deepspeech/examples/vad_transcriber
$ python3 audioTranscript_gui.py

```

![Deepspeech Transcriber](../../doc/audioTranscript.png)


#### 2.1. Sporadic failures in pyqt
Some systems have encountered **_Cannot mix incompatible Qt library with this with this library_** issue.
In such a scenario, the GUI tool will not work. The following steps is known to have solved the issue in most cases
```
(venv) ~/Deepspeech/examples/vad_transcriber$ pip3 uninstall pyqt5
(venv) ~/Deepspeech/examples/vad_transcriber$ sudo apt install python3-pyqt5 canberra-gtk-module
(venv) ~/Deepspeech/examples/vad_transcriber$ export PYTHONPATH=/usr/lib/python3/dist-packages/
(venv) ~/Deepspeech/examples/vad_transcriber$ python3 audioTranscript_gui.py

```
#### 2.2 Useful Tips
#####  The GUI programm immediately crashes when you press start recording
This happens when you don't load the models via the "Browse Models" button, before pressing the "Start recording" button.

#####  What does error XYZ mean?
You can find a list of error codes and what they mean at https://mozilla-voice-stt.readthedocs.io/en/latest/Error-Codes.html