Convert WTV to CAF — Free Online Tool
Convert WTV recordings from Windows Media Center into CAF (Core Audio Format) files, extracting the audio track and encoding it as uncompressed PCM (pcm_s16le) — Apple's preferred lossless audio container for macOS and iOS workflows. This is ideal for pulling broadcast audio content into Apple-native audio tools without any lossy re-encoding artifacts.
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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
WTV files are DVR containers produced by Windows Vista/7/8 Media Center, typically holding H.264 video alongside AAC or MP3 audio captured from digital broadcast signals. During this conversion, FFmpeg strips the video stream entirely and extracts only the audio, re-encoding it into 16-bit signed little-endian PCM (pcm_s16le) — a lossless, uncompressed format — and wraps it in Apple's CAF container. Because CAF is audio-only, all video data and WTV-specific broadcast metadata (program guide info, channel data) are discarded. If the source WTV file contains multiple audio tracks (common with bilingual or SAP broadcasts), only the first track is extracted by default. The resulting CAF file is fully compatible with macOS Core Audio, GarageBand, Logic Pro, and other Apple ecosystem tools.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool, which handles reading the WTV container, demuxing its broadcast audio and video streams, decoding the compressed audio, and writing the new CAF output file. |
-i input.wtv
|
Specifies the input WTV file — a Windows Media Center DVR recording that typically contains an H.264 or MPEG-2 video stream alongside AAC or MP3 broadcast audio. |
-c:a pcm_s16le
|
Decodes the compressed broadcast audio from the WTV file (AAC or MP3) and re-encodes it as 16-bit signed little-endian uncompressed PCM — the default and most compatible audio codec for CAF files within Apple's Core Audio framework. |
-b:a 128k
|
Specifies a target audio bitrate of 128 kbps. This flag has no practical effect on pcm_s16le since uncompressed PCM does not use bitrate-based encoding — its bitrate is determined by sample rate and bit depth. This flag would become relevant if you switch the audio codec to AAC or Opus. |
output.caf
|
Defines the output file as a CAF (Core Audio Format) container. FFmpeg infers the container from the .caf extension and automatically drops the video stream from the WTV source since CAF is an audio-only format. |
Common Use Cases
- Extracting the audio from a recorded TV broadcast in WTV format to edit dialogue or commentary in Logic Pro or GarageBand on macOS
- Archiving the audio portion of a recorded over-the-air TV program as uncompressed PCM in a format natively supported by Apple's audio pipeline
- Pulling a recorded radio simulcast or broadcast interview from Windows Media Center into a macOS podcast production workflow
- Converting the audio track of a DVR-recorded educational program into CAF for use as source material in Apple's Compressor or Final Cut Pro audio editing
- Preparing broadcast audio content recorded via WTV for quality analysis or transcription on macOS without introducing additional lossy compression
- Transferring recorded TV audio from a Windows Media Center archive to an Apple Silicon Mac for further processing in Core Audio-based apps
Frequently Asked Questions
The output audio is encoded as pcm_s16le — 16-bit uncompressed PCM — which is a lossless format. However, if the original WTV file's audio was encoded in AAC or MP3 (as is typical for broadcast recordings), that source audio was already lossy. The conversion does not degrade it further; it simply decodes the lossy source and stores the result as uncompressed PCM. You will not lose any additional quality compared to what was captured during the original broadcast recording.
Both are discarded. CAF is a strictly audio-only container and cannot hold video streams, subtitles, or WTV-specific broadcast metadata such as EPG program guide data, channel information, or recording timestamps. Only the first audio track is extracted and placed into the CAF file. If preserving broadcast metadata is important, consider using an intermediate format like MKV or MP4 before archiving.
Yes, but you need to modify the FFmpeg command. WTV files from bilingual broadcasts often contain multiple audio streams. To select the second audio track, add '-map 0:a:1' to the command: 'ffmpeg -i input.wtv -map 0:a:1 -c:a pcm_s16le output.caf'. The index '0:a:1' refers to the second audio stream (zero-indexed). You can first run 'ffmpeg -i input.wtv' to list all streams and identify the correct track.
The WTV file stores audio in a compressed lossy format like AAC or MP3, while the output CAF file uses pcm_s16le — fully uncompressed audio. Uncompressed PCM at CD quality (44.1 kHz stereo, 16-bit) produces roughly 10 MB per minute, compared to AAC at 128k which is about 1 MB per minute. A one-hour TV recording could produce a CAF file of 600 MB or more. If file size is a concern, you can modify the command to use AAC encoding instead: 'ffmpeg -i input.wtv -c:a aac -b:a 192k output.caf'.
To use AAC instead of uncompressed PCM, replace '-c:a pcm_s16le' with '-c:a aac' and add '-b:a 192k' (or another bitrate) to control quality. For lossless FLAC within CAF, use '-c:a flac'. The CAF format supports AAC, FLAC, Opus, Vorbis, and several PCM variants — all valid options when running the command locally on your desktop. Note that the '-b:a 128k' flag in the default command has no effect on pcm_s16le since uncompressed PCM does not use bitrate-based encoding.
Yes. On macOS or Linux, you can run a shell loop: 'for f in *.wtv; do ffmpeg -i "$f" -c:a pcm_s16le "${f%.wtv}.caf"; done'. On Windows Command Prompt, use: 'for %f in (*.wtv) do ffmpeg -i "%f" -c:a pcm_s16le "%~nf.caf"'. This is especially useful for archiving a large Windows Media Center library, and since WTV files from DVR systems can easily exceed 1GB, running the command locally on your desktop is recommended for bulk processing.
Technical Notes
WTV (Windows Television) files are produced exclusively by Windows Media Center and carry a unique container structure with embedded broadcast-specific metadata not found in standard video containers. When demuxing, FFmpeg handles WTV reliably but may report non-fatal warnings about unknown metadata chunks — these can be ignored. The audio codec inside a WTV file is almost always AAC (from ATSC digital broadcasts) or occasionally MP3 (from analog or MPEG-2 sources), both of which FFmpeg decodes cleanly before writing to PCM. The output pcm_s16le encoding in CAF provides a 16-bit depth, which matches standard CD-quality audio; if the source broadcast was captured at higher bit depths (unusual for over-the-air TV), you may want to use pcm_s24le or pcm_s32le for better fidelity. CAF's audio-only nature means subtitle tracks embedded in WTV (such as CEA-608/708 closed captions) are fully lost in this conversion with no workaround. CAF files are not universally supported outside Apple's ecosystem — Windows and Linux tools may struggle to play them without additional codec support, so this output format is best suited for users working entirely within macOS or iOS environments.