Capturing Footage in Real-Time Without Additional Hardware from RetroPie’s Libretro Core Emulators

The following guide demonstrates how to enable the capture of real-time gameplay footage from various console systems available in the RetroPie emulator suite, a number of which can utilise the RetroArch framework to provide an integrated audio-video recording facility.

Implemented natively on a standard Raspberry Pi, this approach runs without the need for any external hardware (such as an Elgato capture-card).

Topics

• A Little Background Information
• A Note Before Proceeding
• Installing FFmpeg and Selected Codecs
• Rebuilding RetroArch to Enable FFmpeg Recording
• Checking FFmpeg has Been Enabled in RetroArch
• Activating the RetroArch Recording Features
  • An Overview of the Emulators.cfg File
  • Adding Recording Options to the RetroPie Runcommand Menu
  • Recording with the Custom RecordConfig Option
• Performance Enhancements
  • Custom FFmpeg Recording Configuration
  • Tuning the FFmpeg Recording Configuration
  • Recording to an External Storage Device
• Streaming to Twitch
• Related Posts
• External Links

A Little Background Information

My motivation to undertake what has become a sizeable research, development, and experimentation, project grew from a simple desire to obtain recordings of emulators running under RetroPie. I’d previously managed to enable the audio-video feature provided by the Atari ST emulator, Hatari, and was hopeful that a software-only solution was feasible for other systems.

Searching for other emulators offering recording, I found only the non-Libretro variant of Fuse to have in-built facilities; whilst serviceable for capturing ZX Spectrum games, the audio-video files generated by the emulator are of a decidedly non-standard format.

Fundamentally it was my experiments when attempting to transcode footage of Technician Ted captured from Fuse, first with avconv, and later with FFmpeg, and a subsequent enquiry on the RetroPie forum, which spawned the series of articles which form this how-to guide.

For reference, the system used whilst researching this project was a Raspberry Pi 3, overclocked to 1300mhz (please see Overclocking the Raspberry Pi 3: Thermal Limits and Optimising for Single vs Multicore Performance for specifics).

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