Convert Y4M to AIF — Free Online Tool
Convert Y4M video files to AIF audio by extracting and encoding the raw PCM audio stream into Apple's lossless Audio Interchange File Format. Since Y4M is an uncompressed intermediate format and AIF stores uncompressed PCM audio, this conversion preserves full audio fidelity with no quality loss.
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FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
Y4M (YUV4MPEG2) is a headerless, uncompressed video container primarily used as a pipe format between tools like x264, FFmpeg, and VapourSynth — it carries raw YUV video frames and, when present, uncompressed audio. During this conversion, FFmpeg discards the raw YUV video stream entirely and extracts the audio, encoding it as 16-bit big-endian PCM (pcm_s16be) into an AIF container. Because both the source audio in Y4M and the destination AIF format are uncompressed PCM, this is essentially a lossless remux of the audio data into an Apple-compatible wrapper. No re-encoding degradation occurs; the only transformation is packaging the audio into the AIF container structure with proper headers that Mac applications and professional audio tools can read natively.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool. In the browser-based version of this tool, this runs via FFmpeg.wasm compiled to WebAssembly, executing entirely in your browser with no server involvement. |
-i input.y4m
|
Specifies the input Y4M file. FFmpeg reads the raw YUV video frames and any embedded PCM audio from this uncompressed intermediate format file. |
-c:a pcm_s16be
|
Sets the audio codec to 16-bit signed big-endian PCM, which is the standard uncompressed audio encoding used in AIF files. This matches the byte-order convention Apple's AIF format requires and ensures compatibility with Logic Pro, Final Cut Pro, QuickTime, and other macOS audio applications. |
output.aif
|
Defines the output file as an AIF container. FFmpeg infers the AIF format from the .aif extension and writes the pcm_s16be audio stream into it, discarding the Y4M video stream entirely since AIF is an audio-only format. |
Common Use Cases
- Extracting reference audio from a Y4M intermediate file produced during a lossless video encoding pipeline to archive or review the audio track separately in a Mac-native format
- Pulling audio from a Y4M file generated by a VapourSynth or AviSynth script to import into Logic Pro or GarageBand, which natively support AIF
- Converting Y4M test sequences used in codec benchmarking to AIF so the audio component can be evaluated independently in professional audio analysis tools on macOS
- Archiving the audio track from a Y4M master file in AIF format for long-term preservation, taking advantage of AIF's well-documented, lossless PCM structure
- Preparing audio from a Y4M capture or transcoding pipeline for delivery to a Mac-based post-production workflow that requires AIF rather than WAV or FLAC
Frequently Asked Questions
No. Y4M stores audio as raw uncompressed PCM, and AIF also stores audio as uncompressed PCM — in this case 16-bit big-endian PCM (pcm_s16be). The conversion is a lossless remux: the audio sample data is repackaged into the AIF container without any re-encoding, compression, or degradation. The only change is the addition of the AIF file headers and metadata structure.
The raw YUV video stream in the Y4M file is completely discarded. FFmpeg reads the input but only maps the audio track to the output AIF file. AIF is a pure audio format and has no capacity to store video, so this conversion is strictly an audio extraction operation. If you need to keep the video, you would need to convert to a video container like MKV or MP4 instead.
Y4M files frequently have no audio at all, especially when generated by video processing tools like VapourSynth, x264, or ffmpeg piping workflows that only output raw video frames. If your Y4M file contains no audio stream, FFmpeg will throw an error and no AIF file will be produced. You can verify whether your Y4M file contains audio by running 'ffprobe input.y4m' and checking for an audio stream in the output before attempting the conversion.
Yes. AIF supports multiple PCM bit depths, and you can change the codec flag in the FFmpeg command to use pcm_s24be for 24-bit, pcm_s32be for 32-bit integer, or pcm_f32be / pcm_f64be for 32-bit and 64-bit floating point. For example, replace '-c:a pcm_s16be' with '-c:a pcm_s24be' to produce a 24-bit AIF file, which is the standard for professional audio and mastering workflows. Choose a bit depth that matches or exceeds the source audio's original bit depth to avoid unnecessary truncation or upscaling.
You can batch process Y4M files on the command line using a shell loop. On Linux or macOS, run: 'for f in *.y4m; do ffmpeg -i "$f" -c:a pcm_s16be "${f%.y4m}.aif"; done'. On Windows Command Prompt, use: 'for %f in (*.y4m) do ffmpeg -i "%f" -c:a pcm_s16be "%~nf.aif"'. Note that each Y4M file must contain an audio stream for the conversion to succeed. The in-browser tool on this page processes one file at a time, so the FFmpeg command is particularly useful for bulk operations on files you already have locally.
AIF (Audio Interchange File Format) was developed by Apple in the late 1980s as a Mac-native counterpart to Microsoft's WAV format. Both store uncompressed PCM audio, but AIF uses big-endian byte ordering while WAV uses little-endian — which is why the codec here is pcm_s16be (big-endian) rather than pcm_s16le. Functionally both formats offer identical audio quality at the same bit depth and sample rate; the difference is purely structural. AIF integrates natively with macOS applications like Logic Pro, Final Cut Pro, and QuickTime, making it the preferred delivery format in Apple-centric audio and video workflows.
Technical Notes
Y4M files rarely carry audio in practice — the format was designed primarily as a raw video pipe format, and most Y4M generators (VapourSynth, AviSynth, x264 piping) do not embed audio at all. When audio is present, it is stored as raw PCM with no compression. The default output codec, pcm_s16be, produces standard CD-quality 16-bit big-endian PCM, which is the most universally compatible AIF variant across all Apple software. AIF does not support metadata fields beyond basic markers and instrument chunks, so any extended metadata embedded in the Y4M source will not be preserved in the output. The output AIF file size will be determined solely by audio duration, sample rate, and bit depth — roughly 10 MB per minute for 16-bit stereo at 44.1 kHz. Because Y4M video frames are not transcoded but simply ignored, conversion speed is very fast and CPU usage is minimal. One known limitation: AIF has a theoretical 4 GB file size cap due to its 32-bit chunk size field, though in practice audio files rarely approach this limit.