Convert AVI to WTV — Free Online Tool
Convert AVI files to WTV format for use with Windows Media Center, re-encoding video with H.264 and audio with AAC — the codecs expected by the WTV container. This is useful for importing legacy AVI recordings into a Media Center library so they appear alongside recorded TV content with proper metadata support.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your AVI file here
or click to browse
Free — no uploads, no signups. Your files never leave your browser.
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
AVI is a legacy Microsoft container that typically wraps older video codecs such as DivX, Xvid, or MJPEG alongside MP3 audio. WTV, the Windows Television format used by Windows Vista and 7 Media Center, expects H.264 video and AAC audio in its container. Because the codecs almost never match between a typical AVI source and a WTV target, this conversion requires full re-encoding of both streams rather than a simple remux. FFmpeg decodes the AVI video stream and re-encodes it to H.264 using libx264 at CRF 23, and decodes the AVI audio (often MP3 or PCM) and re-encodes it to AAC at 128k bitrate. The resulting WTV file also gains the structural features of the format — including subtitle track support and metadata embedding fields used by Media Center — even though the original AVI carried no subtitle or chapter data.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool, which handles all decoding, re-encoding, and container muxing for this AVI-to-WTV conversion. |
-i input.avi
|
Specifies the input AVI file. FFmpeg reads the interleaved audio and video streams from the AVI container, detecting the specific codecs used (commonly DivX, Xvid, MJPEG for video and MP3 or PCM for audio). |
-c:v libx264
|
Re-encodes the video stream to H.264 using the libx264 encoder, which is the expected video codec in WTV files for Windows Media Center playback compatibility. |
-c:a aac
|
Re-encodes the audio stream to AAC, replacing whatever audio codec was present in the source AVI (typically MP3 or PCM) with the AAC format that WTV defaults to and Media Center handles natively. |
-crf 23
|
Sets the Constant Rate Factor for the libx264 video encode at 23, the default quality level, producing a good balance of visual quality and file size for typical AVI source material being converted to WTV. |
-b:a 128k
|
Sets the AAC audio bitrate to 128 kilobits per second, a standard quality level for AAC that is appropriate for stereo TV-style audio content stored in WTV recordings. |
output.wtv
|
Defines the output filename and tells FFmpeg to mux the re-encoded H.264 video and AAC audio into a WTV container, the Windows Television format used by Windows Media Center for DVR recordings. |
Common Use Cases
- Importing an old AVI home video or downloaded TV recording into a Windows Media Center library so it appears in the DVR section alongside actual broadcast recordings
- Archiving AVI-format TV recordings captured by older Hauppauge or Pinnacle tuner cards into WTV so they are managed by Media Center's metadata and resume-playback system
- Converting AVI files ripped from DVD or VHS digitization projects into WTV so they can be streamed from a Windows 7 Media Center PC to an Xbox 360 acting as an extender
- Preparing legacy AVI video content for playback through Windows Media Center's 'Recorded TV' interface, which filters by container format and expects WTV or DVR-MS
- Migrating a collection of AVI-format fan recordings or sports captures into WTV to take advantage of Media Center's genre tagging and series grouping metadata fields
Frequently Asked Questions
Yes, re-encoding always introduces some generation loss because the video is fully decoded and re-compressed. However, at the default CRF 23 setting with libx264, the quality is visually very close to the source for typical AVI content encoded with DivX, Xvid, or MJPEG. If your source AVI was already heavily compressed, the impact is minimal at normal viewing resolutions. Lower CRF values (e.g., 18) produce higher quality at larger file sizes if you want to preserve more detail.
Yes, as long as the video is H.264 and the audio is AAC or MP3, Windows Media Center on Vista and Windows 7 can play the resulting WTV file. FFmpeg produces a valid WTV container that Media Center recognizes. However, the file will not automatically populate broadcast metadata like episode descriptions or air dates unless you add that information separately, since the source AVI carries none of that data.
It is transcoded, not copied. AVI files commonly contain MP3 (libmp3lame), PCM, or AC3 audio, none of which are the WTV default. FFmpeg re-encodes the audio to AAC at 128k bitrate, which is the standard for WTV content. If your source AVI has multiple audio tracks, FFmpeg will by default select the first one; you can specify additional tracks manually in the command if needed, since WTV does support multiple audio tracks.
The browser-based tool supports files up to 1GB. For larger AVI files, you should copy the exact FFmpeg command displayed on this page and run it directly on your desktop with a locally installed version of FFmpeg. The command is identical — FFmpeg is free and available for Windows, macOS, and Linux from ffmpeg.org. Desktop processing also tends to be significantly faster for large files since it uses your CPU natively rather than WebAssembly.
Change the CRF value in the command. CRF 23 is the default and produces a good balance of quality and file size. Lower values like CRF 18 produce near-transparent quality but larger files; higher values like CRF 28 reduce file size at the cost of more visible compression artifacts. The valid range for libx264 is 0 (lossless) to 51 (worst quality). For example: ffmpeg -i input.avi -c:v libx264 -c:a aac -crf 18 -b:a 128k output.wtv
WTV supports subtitle tracks, but standard AVI files do not carry embedded subtitle streams — subtitles for AVI are typically stored in separate SRT or SSA files. This means the conversion from AVI to WTV will not automatically include subtitles. If you have a separate subtitle file, you can add it to the FFmpeg command manually using the -i flag for the subtitle source and mapping it into the output, since the WTV container is capable of storing the subtitle stream.
Technical Notes
AVI uses a legacy interleaved structure (Audio Video Interleave) with a fixed index at the end of the file, which makes seeking inefficient compared to modern containers and creates a hard 2GB size limit under the original RIFF specification. WTV, by contrast, is a structured binary format derived from the Advanced Systems Format (ASF) and is designed around broadcast DVR workflows — it stores metadata fields for channel, program name, genre, and air time that have no equivalent in AVI. During this conversion, FFmpeg writes an empty WTV metadata envelope since AVI carries none of that broadcast information. The libx264 encoder operates in its default two-pass-approximated CRF mode, which produces variable bitrate output sized to the complexity of the source content. One known limitation is that AVI's OpenDML extension (used for files over 2GB) is handled transparently by FFmpeg but may result in longer processing times as the entire index must be read. The output WTV file will not be recognized as a 'Recorded TV' entry by Media Center's EPG system without a matching XML metadata sidecar, but it will play correctly through the Videos or Recorded TV library sections.