Convert WTV to RMVB — Free Online Tool
Convert WTV recorded TV files from Windows Media Center into RMVB format using H.264 video and AAC audio. This tool re-encodes your broadcast recordings into the variable-bitrate RealMedia container, making them playable in legacy RealPlayer environments and compatible with older media software that doesn't support Microsoft's WTV format.
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FFmpeg Command
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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 produced by Windows Vista/7 Media Center typically contain MPEG-2 or H.264 video alongside AC-3 or AAC audio, wrapped in Microsoft's broadcast-oriented container. During this conversion, the video stream is re-encoded using the libx264 H.264 encoder (since RMVB does not support MPEG-2 or the full range of WTV's native codecs), and the audio is transcoded to AAC at 128k. The RMVB container is a variable-bitrate variant of RealNetworks' RealMedia format, so despite the .rmvb extension the actual encoded streams are standard H.264 and AAC — the container simply wraps them in RealMedia's packaging. Note that WTV-specific features such as multiple audio tracks, embedded EPG metadata, and subtitle streams are not carried over, as RMVB does not support these features.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg program, which handles all the demuxing, decoding, re-encoding, and muxing needed to transform the WTV broadcast recording into an RMVB file. |
-i input.wtv
|
Specifies the input WTV file — a Windows Media Center DVR recording that may contain MPEG-2 or H.264 video, AC-3 or AAC audio, and broadcast metadata. |
-c:v libx264
|
Re-encodes the video stream using the libx264 H.264 encoder. This is necessary because RMVB output via FFmpeg requires H.264, and WTV files may contain MPEG-2 video that cannot be directly copied into this container. |
-c:a aac
|
Transcodes the audio stream to AAC using FFmpeg's built-in AAC encoder. This replaces whatever audio codec was in the WTV file (commonly AC-3 from the broadcast signal), since RMVB output here uses AAC as the default audio codec. |
-crf 23
|
Sets the H.264 Constant Rate Factor to 23, the default quality level. For WTV files sourced from high-definition broadcasts, this typically produces a visually transparent result at a fraction of the original bitrate — lower values like 18 give higher quality at larger file sizes. |
-b:a 128k
|
Sets the AAC audio bitrate to 128 kilobits per second. This is adequate for stereo broadcast audio; if the original WTV contained AC-3 5.1 surround, consider increasing this to 192k or 256k to better represent the source audio. |
output.rmvb
|
Defines the output filename and instructs FFmpeg to mux the re-encoded H.264 video and AAC audio into the RMVB (RealMedia Variable Bitrate) container format. |
Common Use Cases
- Playing recorded TV broadcasts on older media players or set-top boxes that support RMVB but cannot open Microsoft's WTV format
- Archiving Windows Media Center recordings into a more compressed, distributable format for sharing over older file-sharing networks where RMVB was a de facto standard
- Converting recorded sports events or TV series from WTV to RMVB to store on devices with limited storage, taking advantage of H.264's efficient compression over the original MPEG-2 broadcast stream
- Preparing Windows Media Center recordings for playback on legacy Android media apps or Symbian-era devices that have built-in RMVB codec support but no WTV decoder
- Stripping out the DVR metadata and broadcast container overhead from WTV files to produce a clean, streamable video file for use with older RealPlayer-based kiosk or presentation systems
Frequently Asked Questions
Yes, some quality loss is expected. WTV recordings often contain a high-bitrate MPEG-2 broadcast stream, and this conversion re-encodes that video through libx264 at CRF 23, which is visually good but not lossless. The re-encoding introduces generation loss on top of the original broadcast compression. If you need the highest possible quality, lower the CRF value (e.g., CRF 18) in the FFmpeg command before converting.
They are not preserved. WTV supports multiple audio tracks (e.g., secondary language tracks from digital broadcasts) and subtitle streams, but RMVB supports neither. Only the first (default) audio track is transcoded to AAC and included in the output. If your recording contains closed captions or secondary audio, you should extract those separately before converting.
RMVB is a container format, similar to how .mkv or .mp4 are containers. Despite its RealNetworks origins, modern FFmpeg can mux standard codecs like H.264 and AAC into the RMVB wrapper. However, this means playback depends on whether the player can decode H.264 inside an RMVB container — some legacy RealPlayer versions may expect RealVideo codec streams instead, so compatibility is not guaranteed across all RMVB-capable players.
Adjust the -crf value in the command. CRF (Constant Rate Factor) ranges from 0 (lossless) to 51 (worst quality), with 23 as the default. For a higher-quality output — especially useful if your original WTV recording was a high-definition broadcast — try -crf 18. For a smaller file where quality is less critical, try -crf 28. Each change of 6 in CRF roughly halves or doubles the output file size.
Yes. On Linux or macOS, you can run a shell loop: `for f in *.wtv; do ffmpeg -i "$f" -c:v libx264 -c:a aac -crf 23 -b:a 128k "${f%.wtv}.rmvb"; 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 "%~nf.rmvb"`. This is particularly useful for archiving an entire season of recorded TV shows stored as separate WTV files.
WTV files store the raw digital broadcast stream, which is often MPEG-2 video at 15–20 Mbps or higher — a very high bitrate designed for quality, not storage efficiency. Re-encoding to H.264 at CRF 23 typically achieves the same or better perceived quality at 2–5 Mbps, resulting in files 4–8 times smaller. This size reduction is one of the primary practical reasons for this conversion.
Technical Notes
WTV is a Microsoft-proprietary DVR container that encapsulates broadcast transport streams, often containing MPEG-2 Video (from analog or digital tuners) or H.264 (from CableCARD or ATSC captures), along with AC-3 Dolby Digital audio from the broadcast signal. FFmpeg reads WTV well but the output RMVB container imposes significant limitations: no subtitle support, no multiple audio track support, and no chapter markers. The libx264 encoder used here will re-encode whatever video codec was in the WTV (including MPEG-2) into H.264, which is the only video codec supported in this tool's RMVB output. The AAC audio at 128k is a reasonable default for mono or stereo broadcast audio but may be insufficient for AC-3 5.1 surround content — consider raising it to 192k or 256k if the source had surround sound. EPG metadata embedded in WTV (program title, broadcast time, channel info) is entirely lost in the RMVB output, so rename or tag files before converting if that information is important. RMVB is considered a legacy format and is not recommended for new workflows; this conversion is best suited for compatibility with existing older systems rather than long-term archival.