massscriber 0.3.3

Local, free, multilingual audio transcription app powered by faster-whisper.

Massscriber

Massscriber is a local-first audio transcription app built on top of faster-whisper. It is designed for people who want:

• no paid API dependency
• no upload requirement for private recordings
• unlimited local processing
• strong multilingual transcription quality
• both a simple UI and a scriptable CLI

Highlights

• Local transcription with faster-whisper
• Multilingual speech-to-text with automatic language detection
• Batch processing for multiple audio or video files
• Gradio UI for drag-and-drop use
• Local disk mode for direct file paths or folder scans without browser upload
• Configurable subtitle segmentation for cleaner srt and vtt exports
• Experimental speaker diarization with optional pyannote.audio support
• Folder watch CLI workflow for auto-transcribing new media files
• UI watch panel with live logs and history refresh
• Glossary-aware transcript cleanup for names, brands, and recurring corrections
• Saved workflow profiles for watch, glossary, and transcription presets
• Transcript library search with batch review status tracking
• Multi-provider transcription engine for local and hosted APIs
• OpenAI, Groq, Deepgram, AssemblyAI, and ElevenLabs integrations
• Provider-specific API key, timeout, polling, speaker-label, and smart-format controls
• JSON outputs with provider metadata and optional raw API responses
• Built-in system health panel plus doctor CLI command
• Live stage-by-stage progress for long-running transcriptions
• CLI mode for automation and power users
• Export formats: txt, srt, vtt, json
• Quality-first model option: large-v3
• Speed-first model option: turbo
• Installable in supported browsers as a PWA
• Windows desktop bundle build script and GitHub Actions artifact workflow

Supported Inputs

The UI currently accepts:

• .mp3
• .wav
• .m4a
• .flac
• .ogg
• .aac
• .wma
• .mp4
• .mkv

faster-whisper handles media decoding through its own stack, so a manual ffmpeg install is usually not required.

Model Guidance

Model	Best for	Notes
large-v3	Highest accuracy	Best default for serious transcription work
turbo	Fastest practical transcription	Great speed/quality balance
medium	Mid-range systems	Useful fallback for lower VRAM devices
small, base, tiny	Lightweight testing	Faster, but lower accuracy

Important note: no speech recognition model is perfectly error-free. For a fully free and local workflow, large-v3 is one of the strongest practical choices available today.

Providers

Massscriber now supports both local and hosted transcription engines through one shared UI and CLI.

Provider	Type	API key env	Notes
local	Free / local	none	Uses faster-whisper, unlimited runtime, best privacy
openai	Paid API	OPENAI_API_KEY	Supports transcription and translation
groq	Hosted API	GROQ_API_KEY	Very fast hosted Whisper-style transcription
deepgram	Hosted API	DEEPGRAM_API_KEY	Strong utterance and speaker metadata support
assemblyai	Hosted API	ASSEMBLYAI_API_KEY	Async transcription flow with rich review metadata
elevenlabs	Hosted API	ELEVENLABS_API_KEY	Hosted Scribe models with speaker-aware options

Massscriber normalizes all providers into the same downstream features:

• txt, srt, vtt, json
• glossary cleanup
• transcript library indexing
• review-state tracking
• workflow profiles
• folder watch automation

Provider Examples

OpenAI

$env:OPENAI_API_KEY="sk-..."
massscriber transcribe "C:\audio\meeting.mp3" --provider openai --model whisper-1 --formats txt srt json

Groq

$env:GROQ_API_KEY="gsk_..."
massscriber transcribe "C:\audio\episode.mp3" --provider groq --model whisper-large-v3-turbo --formats txt json

Deepgram

$env:DEEPGRAM_API_KEY="dg_..."
massscriber transcribe "C:\audio\call.wav" --provider deepgram --model nova-3 --provider-speaker-labels --formats txt srt json

AssemblyAI

$env:ASSEMBLYAI_API_KEY="..."
massscriber transcribe "C:\audio\interview.mp3" --provider assemblyai --provider-speaker-labels --provider-keywords "Massscriber`nOpenAI"

ElevenLabs

$env:ELEVENLABS_API_KEY="..."
massscriber transcribe "C:\audio\voice-note.m4a" --provider elevenlabs --model scribe_v1 --provider-speaker-labels

Quick Start

Windows helper scripts

install.bat
start_ui.bat

On Windows, install.bat now checks for nvidia-smi and, when an NVIDIA GPU is present, also installs the NVIDIA CUDA runtime Python packages that provide DLLs such as cublas64_12.dll and cudnn64_9.dll.

Manual setup

python -m venv .venv
.venv\Scripts\activate
python -m pip install --upgrade pip
python -m pip install -e .

Run the App

Launch the UI

.venv\Scripts\activate
python app.py

The default UI address is http://127.0.0.1:7860. In supported browsers, the app can also be installed as a PWA for quicker relaunching.

If browser upload becomes unreliable for very large media, use the local disk mode in the UI:

• paste one or more absolute file paths
• or point the app at a folder and let it scan supported media files

The UI also now includes:

• a live system status panel for CUDA/runtime health
• a watch panel for repeated folder scans
• glossary rules for post-transcription cleanup
• saved workflow profiles for repeatable presets
• a transcript library panel for search and batch review
• provider selection with API-aware hosted settings

API-aware settings

Provider mode adds these controls in both UI and CLI:

• provider selector
• provider model selection
• API key or env-var fallback
• base URL override for gateways and proxies
• timeout and polling controls
• smart formatting toggle
• speaker label toggle for supported APIs
• keyword / word-boost field
• optional raw response capture into JSON output

Use the CLI

.venv\Scripts\activate
python app.py transcribe "C:\audio\meeting.mp3" --model large-v3 --formats txt srt json

You can also use the installed console entry point:

massscriber transcribe "C:\audio\meeting.mp3" --model turbo --formats txt srt

Watch a folder for new files

massscriber watch "C:\audio\incoming" --model turbo --once

For a long-running workflow:

massscriber watch "C:\audio\incoming" --model turbo --archive-dir "C:\audio\done"

Check system health

massscriber doctor

Cloud transcription from the CLI

massscriber transcribe "C:\audio\sales-call.mp3" --provider deepgram --model nova-3 --provider-speaker-labels --formats txt srt json

Workflow Profiles

If you reuse the same combinations of model, glossary rules, watch folder, or subtitle settings, save them as a profile in the UI.

• Save the current form values into a named reusable preset
• Reload a preset with one click before starting a job
• Delete or refresh saved profile lists without leaving the app

This is useful for keeping separate setups like:

• podcast cleanup
• meeting transcription
• TV episode subtitle prep
• folder-watch automation for incoming recordings

Transcript Library and Batch Review

The UI now includes a transcript library panel that scans your output directory and builds a searchable review table.

• Search transcript text and metadata from previous runs
• Filter by review state: pending, reviewed, needs-edit, approved
• Preview transcript snippets before opening files manually
• Apply review status updates to selected transcript IDs
• Bulk-apply a review status to the visible filtered result set

This gives you a lightweight local review workflow without needing a separate database service.

Provider-backed transcripts also land in the same library, so your local and hosted runs stay in one searchable archive.

Recommended Settings

Best quality

• Provider: local
• Model: large-v3
• Beam size: 5
• VAD: enabled
• Word timestamps: enabled

Best speed

• Provider: groq or local
• Model: turbo
• Device: cuda when available
• Compute type: float16
• Batch size: 8 or 16

Hosted API workflows

• Use openai when you need OpenAI-hosted transcription and translation
• Use groq when you want very fast hosted Whisper-style transcription
• Use deepgram, assemblyai, or elevenlabs when you want hosted metadata and speaker-aware workflows
• For OpenAI and Groq, keep large files under the provider upload limit; use local, deepgram, or assemblyai for bigger media

Better subtitles

• Subtitle max chars: 36 to 48
• Subtitle max duration: 4.0 to 6.0
• Pause split: enabled

Glossary cleanup

• Use Source => Target format, one rule per line
• Great for names, brands, product terms, and repeated OCR-like mistakes
• Works in UI, CLI, and watch workflows

Example:

Open AI => OpenAI
Chat GPT => ChatGPT
Baris Mancho => Baris Manco

Experimental speaker diarization

• Enable only when you really need speaker labels
• Install the optional extra first:

python -m pip install -e ".[diarization]"

• Provide a Hugging Face token either through HUGGINGFACE_HUB_TOKEN or the UI/CLI field
• Default model: pyannote/speaker-diarization-3.1

Outputs

By default, transcripts are written to the outputs directory:

• txt
• srt
• json

You can also enable vtt from the UI or CLI.

SRT and VTT exports now use configurable subtitle regrouping, so long whisper segments can be re-cut into shorter subtitle cues. JSON outputs also include provider information, remote request identifiers, and optional raw API response metadata.

GPU Notes

If you use an NVIDIA GPU, faster-whisper may require CUDA runtime libraries on your machine. CPU mode works too; it is simply slower. If CUDA libraries such as cublas64_12.dll are missing, Massscriber now falls back to CPU automatically and logs a clear warning instead of stopping the job. On Windows, Massscriber also auto-registers NVIDIA runtime DLL folders from installed Python packages before loading ctranslate2, which helps GPU mode come up cleanly after install.bat.

According to the faster-whisper recommendations:

• int8 is a good default for CPU execution
• float16 or int8_float16 are good GPU options

If you hit CUDA DLL issues on Windows, follow the Windows notes in the official faster-whisper documentation.

Desktop Builds

To create a Windows desktop bundle locally:

build_desktop.bat

Or manually:

python -m pip install -e ".[desktop]"
python build_desktop.py

GitHub Actions also includes a Windows desktop build workflow that uploads a Massscriber-windows artifact for tagged releases and manual runs.

First Run Behavior

The selected model is downloaded automatically on first use. For large-v3, the first run can take a while because the model is large.

Development

Run tests

python -m unittest discover -s tests -v

Local verification

python -m py_compile app.py massscriber\__init__.py massscriber\types.py massscriber\exporters.py massscriber\transcriber.py massscriber\ui.py

Versioning and Releases

• Project version is defined in massscriber.__version__
• Packaging reads the version dynamically from the package
• Human-readable release history lives in CHANGELOG.md
• Release steps are documented in RELEASING.md
• Pushing a tag like v0.1.0 triggers the GitHub release workflow

Roadmap Progress

• Experimental speaker diarization support is now wired in as an optional extra.
• Subtitle exports now have configurable regrouping controls for better cue sizing.
• Folder watch and auto-transcribe workflows now exist in the CLI with persistent state and optional archiving.
• Folder watch is now available in the UI for repeated scan sessions.
• Glossary-aware cleanup and a built-in doctor/status surface are now part of the core app.
• Saved workflow profiles are now available for recurring transcription setups.
• Transcript library search and batch review are now built into the UI.
• Multi-provider hosted API transcription is now integrated across UI, CLI, watch mode, profiles, and exports.
• Desktop packaging now has a local build script and a Windows artifact workflow.

Next Roadmap

• Improve diarization with speaker-aware word-level subtitle cues
• Produce signed desktop installers instead of raw bundles
• Add project-level transcript libraries for large collections
• Add persistent batch actions such as export queues and review assignments
• Add richer transcript editing and glossary-assisted correction workflows
• Add provider failover chains and cost/performance routing presets
• Add remote URL ingestion for providers that support direct media fetch

License

This project is released under the MIT License. See LICENSE.

References

• SYSTRAN/faster-whisper
• openai/whisper
• OpenAI speech-to-text docs
• Groq speech-to-text docs
• Deepgram pre-recorded audio docs
• AssemblyAI speech-to-text docs
• ElevenLabs speech-to-text docs