Convert MOD to 3GP — Free Online Converter

MOD is the Amiga Module audio format, born in 1987 when Karsten Obarski created the Ultimate Soundtracker for the Commodore Amiga. Unlike conventional audio files that store a continuous waveform, MOD files contain short digitized instrument samples (typically 8-bit, 8363 Hz) alongside pattern data that sequences those samples into music — note pitches, volumes, and effects arranged on a grid of channels. The original format supported 4 channels, though later trackers like ProTracker and OctaMED extended this to 8, 16, or even 32 channels. This sample-plus-pattern architecture made MOD files remarkably compact, often fitting entire songs into 100KB-500KB, which was crucial on the Amiga's limited storage.

3GP is a mobile multimedia container standardized by the 3rd Generation Partnership Project for cellular network devices. Converting MOD to 3GP requires a fundamentally different process than typical audio transcoding: the tracker data must first be rendered (synthesized) into a continuous PCM audio stream by interpreting the pattern sequences and mixing the embedded samples at the correct pitches and volumes. Only then can the resulting waveform be encoded into a mobile-friendly codec within the 3GP container. This conversion bridges the gap between the demoscene era of the late 1980s and modern mobile playback.

MOD files are essentially unplayable on modern mobile devices without specialized tracker player apps. The format requires a rendering engine that understands pattern data, sample looping, effect commands (portamento, vibrato, arpeggio), and the Amiga's specific mixing characteristics. Converting to 3GP produces a standard audio file that any mobile phone can play natively, making classic demoscene and game music accessible to listeners who have never encountered a tracker.

Retro gaming enthusiasts and demoscene archivists who maintain collections of MOD files often need to share specific tracks with friends or collaborators who use basic smartphones. A 3GP file can be sent via MMS or messaging apps and plays instantly without requiring the recipient to install any special software. The conversion also captures a specific rendering of the MOD, preserving a particular interpretation of the tracker data for consistent playback.

FFmpeg handles MOD rendering through its libopenmpt or libmodplug decoder, which interprets the binary module structure: the 31 instrument sample slots (each with loop points, finetune, and volume), the pattern order table (up to 128 entries), and the pattern data itself (rows of note/instrument/effect triplets per channel). The renderer processes each row at the tempo defined by speed and BPM effect commands, mixing the 4+ channels with Amiga-style resampling. Effect commands like portamento (3xx), vibrato (4xx), tremolo (7xx), and sample offset (9xx) are applied per-tick. The resulting stereo PCM stream (typically 44100 Hz, 16-bit) is then encoded as AMR-NB or AAC-LC and muxed into the 3GP container conforming to 3GPP TS 26.244.