Extract Audio from Y4M to WAV — Free Online Tool
Extract audio from a Y4M (YUV4MPEG2) video file and save it as a WAV file with uncompressed PCM audio. Since Y4M itself carries no audio, this tool is designed for workflows where Y4M is paired with an external audio stream — it strips the video track and delivers broadcast-ready 16-bit PCM WAV output.
to
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 is a raw, uncompressed video format used primarily as an intermediate format in video processing pipelines — it stores raw YUV pixel data with no compression, and crucially, it has no native audio codec support. When FFmpeg processes a Y4M file that does contain an associated audio stream (for example, when a Y4M file has been muxed with audio data), it discards the raw video stream entirely using the -vn flag and passes the audio through, encoding it as 16-bit signed little-endian PCM (pcm_s16le) inside a WAV container. No re-encoding of the video occurs since the video is simply dropped. The audio output is fully uncompressed, meaning there is no generation loss — every audio sample is preserved exactly as-is in the WAV file.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg command-line tool, which is the underlying engine powering this browser-based conversion via its WebAssembly (FFmpeg.wasm) build. |
-i input.y4m
|
Specifies the input file in Y4M (YUV4MPEG2) format — a raw, uncompressed video container commonly used as an intermediate format in lossless video processing pipelines and inter-application piping. |
-vn
|
Disables all video stream output, which is essential here because Y4M contains raw uncompressed video data that we want to completely discard — only the audio stream (if present) will be passed to the output. |
-c:a pcm_s16le
|
Encodes the output audio as 16-bit signed little-endian PCM, the standard uncompressed audio codec for WAV files. This ensures the output is fully lossless and universally compatible with broadcast systems, DAWs, and media players without requiring any decoder. |
output.wav
|
Defines the output file as a WAV container — a Microsoft/IBM format designed for uncompressed PCM audio that is broadcast-ready, widely supported, and ideal for preserving audio fidelity extracted from a lossless Y4M source. |
Common Use Cases
- Recovering audio from a Y4M intermediate file produced during a lossless video editing or transcoding pipeline where the audio needs to be archived or processed separately.
- Extracting a clean uncompressed audio track from a Y4M file generated by tools like ffmpeg pipe workflows or rav1e encoding setups, where Y4M is the standard inter-application video pipe format.
- Preparing a WAV audio file for import into a Digital Audio Workstation (DAW) after a video post-production workflow that used Y4M as the lossless intermediate format.
- Separating audio from video in a lossless encoding chain — for example, when encoding a Y4M source to AV1 or VP9, pulling the audio out first to process independently before remuxing.
- Archiving the audio component of a Y4M test sequence used in video codec benchmarking or quality evaluation, where the audio reference track is needed for A/V sync validation.
- Batch processing Y4M files produced by screen capture or scientific imaging tools to extract synchronized audio for transcription, analysis, or broadcast delivery.
Frequently Asked Questions
Standard Y4M (YUV4MPEG2) files do not have an official audio stream specification — the format was designed purely for raw video data. However, some tools do mux audio alongside Y4M video in non-standard ways, and FFmpeg can detect and extract that audio when present. If your Y4M file was generated by a pipeline that separates audio and video (which is the norm), this tool will produce an empty or silent WAV file because there is simply no audio stream in the source to extract.
Y4M stores raw, uncompressed YUV video data, which makes it extraordinarily large — a few seconds of 1080p Y4M footage can easily exceed several gigabytes. The WAV output contains only the audio track, which is orders of magnitude smaller. A 10-minute stereo audio track at 16-bit 44.1kHz PCM in WAV format is roughly 100MB, whereas the Y4M source for the same duration of 1080p video would be tens of gigabytes.
No. The output codec is pcm_s16le — 16-bit signed little-endian PCM — which is fully uncompressed and lossless. The audio data is copied into the WAV container without any encoding or decoding that would degrade quality. WAV with PCM audio is one of the highest-fidelity formats available, and it is the standard for broadcast and studio archival work.
Yes. WAV supports multiple PCM variants including pcm_s24le (24-bit) and pcm_s32le (32-bit). To change the bit depth in the FFmpeg command, replace pcm_s16le with your desired codec — for example: ffmpeg -i input.y4m -vn -c:a pcm_s24le output.wav. Only do this if your source audio was originally captured or stored at a higher bit depth, otherwise upsampling a 16-bit source to 24-bit adds no real quality benefit.
On Linux or macOS, you can use a shell loop: for f in *.y4m; do ffmpeg -i "$f" -vn -c:a pcm_s16le "${f%.y4m}.wav"; done. On Windows Command Prompt, use: for %f in (*.y4m) do ffmpeg -i "%f" -vn -c:a pcm_s16le "%~nf.wav". This will process each Y4M file in the current directory and produce a corresponding WAV file with the same base filename.
16-bit signed little-endian PCM (pcm_s16le) is the universal baseline for WAV audio compatibility — it is the format used by audio CDs, and it is natively readable by virtually every operating system, media player, and audio application without requiring any decoder. While WAV also supports 24-bit, 32-bit, float, and even compressed codecs like ADPCM or FLAC, pcm_s16le is the safest default for maximum interoperability and is more than sufficient for most broadcast and archival use cases.
Technical Notes
Y4M files conforming to the YUV4MPEG2 specification do not have a standardized audio stream — the format header describes frame rate, chroma subsampling, and interlacing, but has no audio fields. This means that in a typical Y4M-based lossless pipeline, audio is kept in a separate file (often WAV or FLAC) and only combined at the final output stage. If you are working with such a pipeline, this tool is most useful for extracting audio that has been non-standardly muxed into a Y4M container by a specific tool. The output WAV file uses pcm_s16le encoding, which produces files at approximately 10MB per minute per channel at 44.1kHz. WAV files do not support multiple audio tracks, chapters, or subtitle streams, but they are universally compatible with broadcast systems, DAWs, video editors, and scientific audio analysis tools. One known limitation is that metadata embedded in a Y4M audio stream (such as channel layout or sample rate tags) may not always transfer cleanly into the WAV container, so it is worth verifying playback in your target application after conversion.