WTV to M4B Converter

How to Convert WTV to M4B Online

1. Upload Your WTV File: Drag and drop or click "+ Add Files" to load .wtv recordings exported from Windows Media Center's Users\Public\Recorded TV folder. Batch upload is supported — queue an entire recorded season or interview series and convert them in one pass. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared.
2. Pick a Quality Preset: Default is Highest (re-encodes the source MP2 or AC-3 track to AAC at roughly the original bitrate). Drop to High, Medium, Low, Very Low, or Lowest to shrink the audiobook file for phones or long drives. For exact control, switch to Custom Bitrate and pick Constant Bitrate (predictable size) or Variable Bitrate (better quality per MB), or use Specific file size to target an MB cap.
3. Set Audio Channel, Sample Rate, or Trim (Optional): Switch Audio Channel from Original/Stereo to Mono to halve the file for spoken-word recordings, change Audio Sample Rate (Original, 48000 Hz, 44100 Hz, 24000 Hz, 22050 Hz, 16000 Hz, etc.) to match your playback target, or use Trim to clip commercials, intros, and end-of-program padding before re-encoding.
4. Convert and Download: Click "Convert" and grab each .m4b individually or as a ZIP. No sign-up, no watermark, no email gating.

Why Convert WTV to M4B?

WTV is Microsoft's proprietary recorded-TV container — introduced with the Vista TV Pack 2008 (July 2008), used across Windows 7 Media Center, and effectively orphaned when Microsoft discontinued Windows Media Center in Windows 10 (May 2015). Each .wtv wraps an MPEG-2 video stream alongside an MPEG-1 Layer II or Dolby Digital AC-3 audio track, plus DRM hooks and EPG metadata that only Media Center natively understands. M4B (MPEG-4 Audiobook) keeps the audio and discards the video, packaging an AAC track inside an MP4 container with chapter-marker and bookmark support — the format Apple Books, Audible, and most modern audiobook apps treat as "remember my place." Common reasons to extract:

• Archive talk shows, news, and interview programs — A two-hour late-night interview block recorded as a 6–8 GB WTV becomes a 60–120 MB M4B at 128 kbps stereo AAC; the file fits on any phone and resumes where you left off.
• Move recordings off Windows Media Center — Since Media Center was removed in the Windows 10 upgrade path, surviving .wtv libraries can only be played in third-party tools (VLC plays them; many phones don't). Re-encoding to M4B makes the audio portable to iOS, Android, macOS, and any AAC-compatible player.
• Audiobook-style listening on Apple Books / Apple Podcasts — M4B is the only audiobook format Apple's apps auto-recognise for chapter navigation and last-position resume; MP3 and M4A restart from the top.
• Long-form material on the road — A multi-hour TV documentary or sermon series at 64 kbps mono AAC sounds clean on car speakers and fits dozens of hours per GB.
• Audible / iTunes-style library workflow — M4B drops straight into iTunes (or Music.app on macOS Catalina+) and is categorised under the Audiobooks library, separate from your music.
• Strip out DRM-free TV audio for transcription — Comedy specials, panel shows, and call-in radio simulcasts recorded over the air carry no broadcast flag; the extracted AAC track feeds straight into transcription tools.

Need a different audio target? Try WTV to MP3 for universal compatibility, WTV to M4A for plain AAC without audiobook metadata, or WTV to AAC for the raw codec. Keeping the video? Use WTV to MP4 first.

WTV vs M4B — Format Comparison

AAC Bitrate Guide for M4B Audiobooks

Sizes below assume a 1-hour recording. Stereo is appropriate for music-bearing content; mono halves the size for spoken word.

Frequently Asked Questions

Will my M4B remember its playback position in Apple Books?

Yes — that's the whole point of the .m4b extension. Apple Books, Apple Music's audiobooks library, Audible, and most third-party players (BookPlayer, Smart AudioBook Player, Bound, Listen Audiobook Player) inspect the file extension and treat anything ending in .m4b as an audiobook: the app saves the playback position when you stop, reopens to the same spot, and keeps the file in a separate library from music. The same AAC stream renamed to .m4a would not auto-bookmark in Apple's apps.

Does converting to M4B add chapter markers automatically?

No — the encoder writes a single continuous audio stream. Chapter markers in M4B are a separate metadata atom (chpl for legacy iTunes, plus a chap track) that you author after the fact with tools like mp4chaps, MP4Box, Audiobook Builder, or ChapterTool. If your WTV recording spans multiple shows you want as chapters, convert each segment separately and merge them with a chapter-aware tool.

Why is my WTV file so large compared to the M4B output?

WTV stores broadcast-quality MPEG-2 video (typically 4–8 GB per HD broadcast hour) plus an audio track that's usually 192–384 kbps MP2 or AC-3. M4B keeps only the AAC-encoded audio, so the resulting file is one or two orders of magnitude smaller — a one-hour 6 GB WTV typically becomes a 30–80 MB M4B depending on the bitrate you pick.

My WTV won't open — does Windows Media Center DRM block conversion?

Some .wtv files recorded from CableCARD-protected channels carry a broadcast flag that prevents playback (and conversion) outside the recording machine. Over-the-air ATSC recordings, cable channels not flagged "copy once," and most basic-tier programming carry no DRM and convert cleanly. If you get an immediate decode error, the file is likely DRM-locked; nothing on the open web can decrypt it.

Should I keep stereo or switch to mono?

For interview shows, news, sermons, lectures, and audiobooks, mono at 64 kbps AAC sounds identical to most listeners and halves the file size. Keep stereo when the broadcast contains music beds, applause, panel banter where stereo separation matters, or live performances. Stereo at 64 kbps splits the bit budget across two channels and can sound thinner than mono at the same rate.

Will my M4B play on Android and Windows, or only Apple devices?

The AAC stream itself plays everywhere AAC is supported — Android (native since 2.3), Windows 10/11, VLC, foobar2000, MPV, and any modern car stereo. The audiobook-specific behaviours (auto-bookmark, separate library, chapter UI) only fire in apps that look for the .m4b extension: Apple Books on iOS/macOS, Smart AudioBook Player and BookPlayer on Android, foobar2000 with the bookmark plugin on Windows. On apps that don't, the file plays as a regular AAC track.

Can I trim out commercials before converting?

Yes — open the Trim control to set a start time and end time in HH:MM:SS.mmm format before encoding. For multi-break removal across a single recording you'll need to split into segments and re-join; for one-shot intro/outro trims the Trim control here is the fastest option. After conversion you can also use Audio Cutter to slice the M4B further.

How do I get a 24-hour talk-radio archive into one M4B?

Convert each hourly WTV to M4B individually at 64 kbps mono AAC (~29 MB each, ~700 MB for the full day), then merge with an audiobook-aware tool like Audiobook Builder (macOS) or mp4box -cat so the resulting file carries 24 chapter markers — one per hour — and resumes correctly across the whole archive in Apple Books.

Is anything uploaded to your servers?

processing happens on our servers and files are removed after the session ends. No account is required and there are no watermarks, file-count caps, or hidden Pro tiers gating WTV-to-M4B conversion.