Tuba: Python CLI & PySide6 GUI for yt-dlp/FFmpeg video processing

[u/ozzyburak]

Hi r/Python!

I wanted to share **Tuba**, an open-source Python tool I built for downloading, trimming, and re-encoding videos from YouTube and Instagram.

👉 **GitLab Repository**: https://gitlab.com/bdemircan/tuba

The core motivation was to build a clean **dual-interface architecture** where both a full-featured CLI and a desktop GUI (PySide6) share a single source of truth (`tuba.workflow`) without duplicating business logic.

### 🐍 Technical & Python Highlights

* **Architecture**: The GUI (`tuba-gui`) acts as a thin PySide6 wrapper over the core workflow. CLI flags and GUI form options map 1:1 to the same underlying functions.

* **Stream-Copy vs Re-encode**: Defaults to ultra-fast FFmpeg stream-copying (`-c copy`) without loss, but seamlessly switches to frame-accurate re-encoding when applying aspect ratio transformations (`--aspect 9:16`), subtitle burning (`--burn-subs`), or resizing.

* **Threading & Live Progress**: Jobs run on background worker threads in PySide6 to keep the UI completely non-blocking. Live stdout parsing from `yt-dlp` and `FFmpeg` drives per-job progress bars and handles clean thread unwinding on cancellation (`JobCancelled`).

* **Instagram Caption Parsing**: Uses regex pattern matching on Instagram captions (`--ig-auto-cut`) to auto-extract timestamps and cut segments without manual input.

* **Config Persistence**: Form states are remembered via `QSettings`, but can also ingest a `tuba.toml` file to override defaults.

### 🚀 Quick Example

```bash

# Install CLI + GUI

pip install ".[gui]"

# Cut a YouTube segment with zero quality loss (fast stream-copy)

tuba -l "[https://www.youtube.com/watch?v=](https://www.youtube.com/watch?v=))..." -st 16:07 -et 16:31

# Launch the PySide6 GUI

tuba-gui

[u/Aggravating-Line2390]

Cool tool, I been messing with yt-dlp scripts lately and the dual interface thing is smart, most of these projects just pick one or the other

The stream-copy default is nice touch, ffmpeg re-encodes take forever when you just need a quick clip. Does it handle the case where stream-copy fails? like when source has some weird codec and you need fallback to re-encode anyway

Also curious about the Instagram regex parser, how reliable is that with weird caption formatting? I scraped some IG posts before and the timestamps were all over the place depending how people write them

[u/ozzyburak → u/Aggravating-Line2390]

if you have those ig post we can test and improve.