Convert WTV to 3G2 — Free Online Tool
Convert WTV broadcast recordings from Windows Media Center into 3G2 files optimized for CDMA mobile networks. This tool re-encodes the video using H.264 (libx264) and audio using AAC — the native codecs for 3G2 — making DVR recordings compatible with older mobile devices and 3GPP2-based workflows.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your WTV file here
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Settings
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 Microsoft's proprietary DVR container used by Windows Vista and 7 Media Center, typically storing MPEG-2 or H.264 video alongside AC-3 or AAC audio with embedded broadcast metadata. During conversion, FFmpeg demuxes the WTV container and re-encodes the video stream to H.264 using libx264 with a CRF of 23, and transcodes the audio to AAC at 128k bitrate — both of which are the standard codecs for the 3G2 container. The -movflags +faststart flag reorganizes the MP4-family atom structure so the 3G2 file's metadata sits at the beginning of the file, enabling progressive playback on mobile networks. Note that WTV-specific features like subtitles, multiple audio tracks, and broadcast metadata will not carry over to 3G2, which has no support for those features.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary — the open-source multimedia processing engine running here via WebAssembly (FFmpeg.wasm) entirely in your browser, with no server upload required. |
-i input.wtv
|
Specifies the input file as a WTV container — FFmpeg will demux the proprietary Microsoft broadcast recording format, extracting its video, audio, and any subtitle or metadata streams for processing. |
-c:v libx264
|
Encodes the output video stream using libx264, the H.264 encoder. H.264 is the required video codec for 3G2 compatibility and provides efficient compression suited to the low-bitrate mobile streaming use case the format was designed for. |
-c:a aac
|
Transcodes the audio to AAC, which is the standard audio codec for 3G2 files. This is necessary because WTV recordings often contain AC-3 (Dolby Digital) audio from broadcast sources, which is not supported in the 3G2 container. |
-crf 23
|
Sets the H.264 Constant Rate Factor to 23, which is the FFmpeg default and represents a balanced quality-to-file-size tradeoff. For TV broadcast content, consider lowering this to 18 for higher fidelity, or raising it to 28 for smaller files. |
-b:a 128k
|
Sets the AAC audio bitrate to 128 kilobits per second, which provides acceptable stereo audio quality for speech and music from broadcast recordings while keeping the 3G2 file compact for mobile use. |
-movflags +faststart
|
Moves the MP4/3G2 moov metadata atom to the beginning of the output file, enabling the video to begin playing before the full download completes — a requirement for streaming 3G2 files over CDMA mobile networks. |
output.3g2
|
Specifies the output filename with the .3g2 extension, signaling to FFmpeg to write a 3GPP2-compliant container — the mobile video format developed for CDMA networks under the 3GPP2 standard. |
Common Use Cases
- Trimming down a recorded TV episode from Windows Media Center to share as a small 3G2 clip on an older CDMA-capable mobile device
- Archiving a short segment of a DVR-recorded broadcast in a format compatible with legacy 3GPP2 media players or feature phones
- Preparing a Windows Media Center recording for playback on embedded automotive or industrial systems that require the 3G2 container
- Reducing the file size of a WTV broadcast recording for transfer over slow or metered CDMA mobile data connections
- Converting a WTV sports or news clip into a mobile-friendly 3G2 file for playback in older Qualcomm-based media environments
- Extracting a usable video clip from a WTV DVR archive when only 3G2-compatible playback tools are available on the target device
Frequently Asked Questions
No. WTV files can carry subtitle and closed-caption streams from the original broadcast, but the 3G2 container format has no support for subtitle tracks. FFmpeg will silently drop any subtitle or caption data during this conversion. If preserving subtitles is important, consider converting to a format like MP4 or MKV instead, which support embedded subtitle tracks.
The 3G2 container does not support multiple audio tracks, so only the first (default) audio track from the WTV file will be included in the output. FFmpeg will transcode that primary track to AAC at 128k and discard the remaining audio streams. If you need to preserve a specific secondary audio track, you can add '-map 0:a:1' to the FFmpeg command to select it by index before converting.
WTV files from Windows Media Center are typically large — often recording at broadcast bitrates of 8–15 Mbps or higher. The 3G2 format was designed for low-bitrate mobile transmission, and the default CRF 23 H.264 encoding will significantly compress the output. A one-hour WTV recording that might be 6–8 GB could compress down to a few hundred megabytes, depending on the content's complexity. You can adjust the CRF value in the FFmpeg command to trade quality for size.
The '-crf 23' flag controls video quality using H.264's Constant Rate Factor scale. Lower values produce higher quality and larger files (0 is mathematically lossless, 18 is visually near-lossless), while higher values reduce quality and file size (35 and above becomes noticeably degraded for TV content). For broadcast recordings where detail matters, try '-crf 18' for higher fidelity, or '-crf 28' if you need a smaller file for mobile transfer. You can also raise the audio bitrate from '-b:a 128k' to '-b:a 192k' for better audio quality.
Yes. On Linux or macOS, you can use a shell loop: 'for f in *.wtv; do ffmpeg -i "$f" -c:v libx264 -c:a aac -crf 23 -b:a 128k -movflags +faststart "${f%.wtv}.3g2"; done'. On Windows Command Prompt, use 'for %f in (*.wtv) do ffmpeg -i "%f" -c:v libx264 -c:a aac -crf 23 -b:a 128k -movflags +faststart "%~nf.3g2"'. This is especially useful for processing large WTV archives from a Windows Media Center library, since the browser tool handles only one file at a time.
The 3G2 format is part of the MP4/ISOBMFF family and stores a metadata atom (moov) that describes the file's structure. By default, FFmpeg writes this atom at the end of the file after encoding completes. The '+faststart' flag moves the moov atom to the beginning of the file in a post-processing step, which is essential for streaming over CDMA mobile networks — the device can begin decoding the video before the entire file has been downloaded.
Technical Notes
WTV is a proprietary Microsoft container that wraps MPEG-2 Transport Stream data, and its internal video codec is typically MPEG-2 Video or H.264, depending on the broadcast source and tuner hardware. Audio is commonly AC-3 (Dolby Digital) from over-the-air recordings. Because FFmpeg must fully decode MPEG-2 video (or re-encode existing H.264) into a new H.264 stream for the 3G2 container, this is a full transcode — not a remux — and will take more time and CPU than a simple container swap. The 3G2 format is a strict subset of the MP4/3GP family and imposes limitations: no subtitle tracks, no chapter markers, no multiple audio streams, and a practical cap on audio bitrate (up to 256k AAC). Broadcast metadata embedded in the WTV file (program title, channel, recording time, episode info) will be lost entirely in the output. For archival purposes where metadata preservation matters, converting to MKV or MP4 is a better choice. The output 3G2 file will be compatible with 3GPP2-compliant players, older Qualcomm-based mobile devices, and any modern player that handles the MP4 family.