Subprocesses and dependencies
Local programs used by Synthezia
Section titled “Local programs used by Synthezia”| Program or dependency | Role in the current application | Data it handles |
|---|---|---|
| FFmpeg | Converts selected media or recorded audio into a normalized local WAV file. | Local source media and generated WAV files. |
| FFprobe | Reads media duration for the selected local audio path. | Local media path and metadata returned by the probe. |
| whisper.cpp command-line program | Transcribes normalized audio with a local Whisper model. | Local WAV path, local model path, and resulting transcript segments. |
| Bundled Ollama runtime | Serves local summary, chat, embedding, model-list, model-pull, and model-delete requests over loopback HTTP. | Local transcript/context requests, local embedding input, and local models. |
| cpal and ScreenCaptureKit | Capture microphone and supported macOS system-audio paths for live recording. | Live audio obtained after the relevant macOS permission is granted. |
The release bundle configuration lists whisper-cli, ffmpeg, ffprobe, and ollama as external binaries. In development builds, the runtime can use a compatible system-installed binary as a fallback; do not treat that development behavior as evidence of release compatibility.
How the runtimes are started
Section titled “How the runtimes are started”Synthezia invokes FFmpeg, FFprobe, and whisper.cpp with local paths during the applicable media workflow. It starts the bundled Ollama runtime as a child process when a reachable local instance is not already available, configures its model directory under Synthezia application data, and communicates with it through a loopback address.
Ollama model pulls are initiated through that loopback service, but the runtime contacts the registry configured for Ollama. Whisper model downloads are a separate application request to the configured Hugging Face source.
Security review implications
Section titled “Security review implications”- A release review should verify the exact binary provenance, code signatures, and runtime behavior of the shipped artifact.
- Local subprocesses process sensitive local content; protect the device account and application data accordingly.
- Model download, provider, and subprocess behavior can change with the shipped versions. Review the exact release rather than relying on this page as a supply-chain guarantee.