ASF to WTV Converter
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Supports: ASF
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Need help?Convert ASF to WTV
ASF is Microsoft's Advanced Systems Format — the container behind .asf and .wmv files, normally holding Windows Media Video and Windows Media Audio. WTV is a different Microsoft container entirely: Windows Recorded TV Show, the format Windows Media Center wrote when it recorded from a TV tuner. This converter decodes the ASF streams and re-encodes them into a WTV file. Nothing is copied through untouched; Windows Media Video and the codecs a WTV carries have no shared bitstream.
WTV is a narrow target, so it is worth being blunt about who it is for: people feeding a legacy Media Center library, a Windows 7 or 8 home-theatre box, or a tool that scans a Recorded TV folder by extension. If you just want the clip to play, ASF to MP4 is the better conversion.
How to Convert ASF to WTV
- Upload Your ASF File: Drag the
.asffile onto the page or click "Add Files". Several files can be queued and they all convert with the same settings. Uploads travel over an encrypted connection and are processed on our servers. - Set File Compression: This group opens on Quality Preset at Very High (Recommended). Specific file size, Constant Bitrate, Variable Bitrate, Constant Quality and Constraint Quality are the alternatives. Because the video is encoded with H.264 here, the preset resolves to a true constant-quality target rather than a bitrate guess.
- Set Video Resolution and Trim: Video resolution opens on Keep original; Resolution Percentage, Preset Resolutions, Width, Height and Width x Height are the other modes. Trim takes a start time and a duration if you only want part of the recording.
- Convert and Download: Click Convert and save the
.wtvfile. No sign-up, no watermark; uploads and converted files are deleted automatically after a few hours.
There Are No Codec Choices on This Page — Here Is Why
Most video pages here let you pick a video and an audio codec. This one does not, and it is worth explaining rather than hiding. Every codec entry in the picker is gated on the output container, and WTV appears on none of those allow-lists, so both lists come up empty. What you get instead is fixed:
| Stream | What this page produces | Where the choice comes from |
|---|---|---|
| Video | H.264 | The page resolves H.264 for WTV output and passes it straight to the encoder |
| Audio | AC-3 (Dolby Digital) | No audio codec is requested, so FFmpeg's own WTV muxer default applies |
| Container | WTV | Written by FFmpeg's WTV muxer, not by Windows |
| Chapters, thumbnails, guide data | Not written | Media Center metadata is generated by Media Center, not by a converter |
We ran a 4-second 640×480 WMV2 + WMA2 .asf clip through the same H.264-into-WTV path this page uses and probed the result: one h264 video stream at 640×480 and one ac3 stream at 44,100 Hz stereo. That is the shape every conversion from this page produces.
What a WTV File Actually Is
| Property | Value |
|---|---|
| Full name | Windows Recorded TV Show |
| Introduced with | Windows 7 Media Center, replacing the older DVR-MS container used by Windows XP Media Center Edition and Windows Vista |
| Normal contents | The MPEG-2 or H.264 broadcast stream a TV tuner captured, plus Media Center's own recording metadata |
| Created by | Windows Media Center — which Microsoft dropped when Windows 10 shipped in 2015 |
| Plays in | VLC and other FFmpeg-based players; Media Center on Windows 7 and 8 |
| Editable in | Very little — most editors want the recording converted out to MP4 or MKV first |
| Sensible alternative | MP4 for playback and sharing, MKV when you want to keep multiple audio tracks |
Because Media Center is gone from modern Windows, a .wtv file you create today is essentially an archive-shaped container rather than something the operating system knows what to do with. If a .wtv file is what a specific tool wants, this page produces one. If you inherited .wtv recordings and want them usable, the traffic runs the other way — see WTV to MP4.
Frequently Asked Questions
Will the WTV file I create here open in Windows Media Center?
Only if you still run Media Center, which means Windows 7 or Windows 8 — Microsoft did not carry it into Windows 10. Even there, treat it as playback rather than a library import: a genuine Media Center recording carries guide data, chapter marks and a thumbnail that the application wrote at record time, and a converter has no way to invent those. The video and audio inside our file are standard and play fine; what is missing is the Media Center scaffolding around them.
Why is my WTV file larger than the ASF I started with?
Because the default preset targets picture quality, not size. Very High resolves to a tight constant-quality H.264 target, and it shifts tighter still on small frames — a standard-definition ASF from the Windows Media era gets encoded very conservatively, which often lands above the original file size. If size is what matters, switch File Compression to Specific file size and name a number, or step the preset down to Medium or Low.
Can I keep the original Windows Media Video stream instead of re-encoding?
No. Every conversion here is a full decode and re-encode; there is no pass-through path. That means one generation of loss on both the picture and the sound, on top of whatever loss the WMV and WMA encoders already baked in. It also means there is no way to put a WMV stream inside the WTV file — the video comes out as H.264.
The audio came out as AC-3. Can I change it?
Not on this page. The audio codec list is empty for WTV output, so no codec is requested and FFmpeg's WTV muxer falls back to its own default, which is AC-3. AC-3 is a reasonable outcome for a TV-recording container — it is what broadcast streams normally carry — but if you need a specific audio codec, convert to a container that exposes the choice, such as ASF to MKV.
Does converting to WTV remove the interlacing lines from an old TV capture?
No. There is no deinterlacing anywhere in this pipeline, so a source captured from interlaced broadcast keeps its comb artifacts, and they get re-encoded into the H.264 stream exactly as decoded. The same caution applies to pixel aspect: leaving Video resolution on Keep original preserves the source's sample aspect ratio, but any resize flattens it to square pixels, which visibly stretches an anamorphic source. If your capture is anamorphic, set an explicit Width x Height matching its display shape instead of using a percentage or a preset.
What is the difference between ASF, WMV and WTV?
ASF is the container; WMV is a video codec that normally lives inside it. A .wmv file is an ASF file whose video happens to be Windows Media Video, which is why the two extensions behave almost identically. WTV is unrelated to both — a separate Microsoft container for tuner recordings, with its own metadata layout. Converting ASF to WTV is a container change plus a full re-encode, not a rename.
Can I trim a long recording before converting it?
Yes, two ways. Trim on this page takes a start time and a duration and encodes only that range, which is the simplest option. If the source is large enough that uploading the whole thing is the bottleneck, cut it first with the Video Cutter, which accepts .asf directly, then convert the shorter clip.
How are my files handled while they are on your servers?
The .asf file is uploaded over an encrypted connection, converted on our servers, and both the upload and the finished .wtv are deleted automatically after a few hours. There is no account to create, no watermark on the output, and files are never shared or made public. The real ceiling on a long tuner recording is upload size and time rather than anything about the format itself.