MyMediaTools

Convert J2B to AIFC — Free Online Tool

Convert J2B game audio files from Jazz Jackrabbit 2 into AIFC format, decoding the ASYLUM Music Format module and re-encoding it as uncompressed PCM audio (pcm_s16be) in Apple's extended AIFF container — ideal for preserving the audio in a professional, lossless format compatible with macOS and pro audio tools.

FFmpeg Command

Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg

Free — no uploads, no signups. Your files never leave your browser.

Estimated output:

Conversion Complete!

Download

How It Works

J2B files contain ASYLUM Music Format (AMF) module music wrapped in a custom Jazz Jackrabbit 2 header. During conversion, FFmpeg strips the J2B header, interprets the module music data, and synthesizes it into a linear PCM audio stream. That stream is then encoded as 16-bit big-endian PCM (pcm_s16be) and written into an AIFC container — Apple's compressed/uncompressed AIFF extension. Because module music is procedurally generated rather than stored as raw waveform data, FFmpeg must render the tracked notes and instrument samples into a continuous audio stream before writing to AIFC. The result is a standard, uncompressed audio file rather than a tracker module.

What Each Flag Does

Flag What it does
ffmpeg Invokes the FFmpeg program, which handles the J2B header parsing, ASYLUM module synthesis, PCM encoding, and AIFC container writing in a single pipeline.
-i input.j2b Specifies the input J2B file — FFmpeg detects the Jazz Jackrabbit 2 wrapper, strips its custom header, and hands the embedded ASYLUM module data to the appropriate decoder for synthesis.
-c:a pcm_s16be Sets the audio codec to 16-bit signed big-endian PCM, which is the standard uncompressed audio codec for AIFC and AIFF containers and ensures lossless, universally compatible output.
-b:a 128k Specifies an audio bitrate of 128k; for uncompressed PCM codecs like pcm_s16be this parameter has no effect on encoding quality (PCM bitrate is fixed by sample rate and bit depth), but it is passed as a default parameter by the tool.
output.aifc Defines the output filename and signals FFmpeg to write the result in AIFC container format, which supports both compressed and uncompressed PCM audio and is natively compatible with macOS and professional audio applications.

Common Use Cases

  • Archiving Jazz Jackrabbit 2 level music in an uncompressed, lossless format for long-term preservation without lossy degradation
  • Importing synthesized J2B game music into Logic Pro, GarageBand, or other macOS-native DAWs that natively support AIFC files
  • Preparing Jazz Jackrabbit 2 music tracks for use in video editing timelines on macOS, where AIFC is a well-supported professional audio format
  • Extracting and converting J2B music for use as sound effects or background audio in a new project, where uncompressed PCM gives maximum flexibility for further editing
  • Studying or remixing the synthesized audio output of ASYLUM module music by converting it to a format that exposes the raw PCM waveform for analysis in audio editors
  • Creating high-quality audio assets from retro game soundtracks for use in fan projects, tributes, or game-related video content

Frequently Asked Questions

The conversion from J2B to AIFC using pcm_s16be is effectively lossless at the PCM level. J2B files store music as tracker module data (instrument samples and note sequences), and FFmpeg renders this into a 16-bit big-endian PCM stream — the same bit depth used on audio CDs. There is no lossy compression applied in the AIFC output. The only caveat is that the original tracker format encodes music as instructions rather than waveform data, so the rendered output depends on FFmpeg's module synthesis quality.
AIFC (also called AIFF-C) is an extension of Apple's AIFF format that was designed to support both uncompressed PCM and compressed audio codecs. AIFF only supports uncompressed PCM. In practice, when using the pcm_s16be codec (uncompressed 16-bit big-endian PCM), the audio data in AIFC is identical to what AIFF would store — the difference is just the container header. Both formats are widely supported on macOS and in professional audio software, and most tools that open AIFF will also open AIFC.
Yes. AIFC supports several PCM codecs beyond pcm_s16be, including pcm_s24be (24-bit), pcm_s32be (32-bit integer), pcm_f32be (32-bit float), and pcm_f64be (64-bit float). To use a higher bit depth, you would change the -c:a flag in the FFmpeg command — for example, replace '-c:a pcm_s16be' with '-c:a pcm_s24be'. However, since J2B module audio is typically synthesized from relatively low-resolution sample data, increasing bit depth beyond 16-bit may not yield perceptible quality improvements for this specific source format.
J2B files carry minimal metadata — primarily the custom Jazz Jackrabbit 2 header data and whatever is embedded in the underlying ASYLUM module. FFmpeg does not reliably extract or map this internal module metadata to AIFC tags during conversion. You should expect the output AIFC file to have little to no embedded metadata, and you may need to add title, artist, or album information manually using an audio tag editor after conversion.
Because pcm_s16be is an uncompressed codec, the -b:a bitrate flag in this command has no meaningful effect on quality — PCM bitrate is determined entirely by sample rate and bit depth. To control the output sample rate, add '-ar 44100' (for CD quality) or '-ar 48000' (for broadcast standard) to the command before the output filename. For example: ffmpeg -i input.j2b -c:a pcm_s16be -ar 44100 output.aifc. The bit depth is controlled by your choice of PCM codec (pcm_s16be, pcm_s24be, etc.).
Yes, you can batch process J2B files on your desktop using a shell loop. On Linux or macOS, run: for f in *.j2b; do ffmpeg -i "$f" -c:a pcm_s16be "${f%.j2b}.aifc"; done. On Windows (PowerShell), use: Get-ChildItem *.j2b | ForEach-Object { ffmpeg -i $_.FullName -c:a pcm_s16be ($_.BaseName + '.aifc') }. The in-browser tool on this page processes one file at a time, so the FFmpeg command is especially useful for bulk conversion of a full Jazz Jackrabbit 2 music library.

Technical Notes

J2B is a proprietary wrapper format specific to Jazz Jackrabbit 2, enclosing an ASYLUM Music Format (AMF) tracker module inside a simple custom header. FFmpeg identifies and decodes the AMF data by synthesizing the module's tracked note sequences and instrument samples into a rendered PCM stream. This synthesis process means the output is a static audio rendering, not a losslessly re-encoded version of the original data — the tracker instructions themselves are not preserved in AIFC, only the rendered waveform. The output codec, pcm_s16be, is 16-bit signed big-endian PCM, which is the native byte order for both AIFF and AIFC on big-endian Apple hardware and is widely readable by professional audio software on all platforms. AIFC supports optional codec markers in its header, and when using uncompressed PCM the AIFC file will be essentially identical in audio content to an AIFF file of the same bit depth. File sizes will be substantially larger than the source J2B, since a short module file can render into several minutes of uncompressed PCM audio. AIFC does not support subtitles, chapters, or multiple audio tracks, so this is a straightforward single-stream audio conversion.

Related Tools

Convert J2B to DSS Convert J2B to ALAC Convert J2B to OGG Convert CAVS to AIFC Convert M2TS to AIFC Convert AIFF to AIFC Compress J2B Trim Video or Audio J2B