ASF to MTS Converter

Convert ASF to MTS: What This Tutorial Covers

This is a narrow, specific job: you have older Windows Media clips — .asf or .wmv files, Microsoft's Advanced Systems Format — and you need them as .mts, the AVCHD camcorder format, usually so a video editor that expects AVCHD footage will accept them alongside real camcorder clips. This walk-through covers how to set the codec and audio correctly, what quality you can honestly expect from the re-encode, and the cases where converting to MTS is the wrong move and ASF to MP4 is what you actually want.

How to Convert ASF to MTS

1. Upload Your ASF File: Drag and drop your .asf (or .wmv) file onto the page or click "+ Add Files." Queue several at once and they all run with the same settings.
2. Set the Video Codec: Open Show All Options and confirm Video Codec is H.264 — that is the AVCHD-standard codec for .mts and the default here. Leave it on H.264 unless an editor specifically asked for something else.
3. Set the Audio Codec and Quality (Optional): Under Audio Codec, the default is AAC; switch it to AC3 if your AVCHD editing project expects Dolby AC-3 audio. Under File Compression, leave the Preset on Very High (Recommended), or pick Constant Bitrate or Specific file size for tighter control. Use Video resolution and Trim only if you need to scale or cut.
4. Convert and Download: Click "Convert" and save your .mts file. No sign-up, no watermark.

Walk-through: Getting an MTS an AVCHD Editor Will Accept

The reason to convert to .mts at all is almost always an editing workflow. MTS is the on-camcorder file name for AVCHD — the format Sony and Panasonic introduced in 2006 — and it carries H.264/AVC video with Dolby AC-3 or linear PCM (LPCM) audio inside an MPEG transport stream. If your editor or project was built around AVCHD camcorder footage, feeding it a Windows Media .asf directly may be rejected; re-wrapping the video as H.264 inside an .mts is what makes the old clip sit next to the camcorder clips.

The settings that matter for that goal:

• Keep Video Codec on H.264. AVCHD is an H.264 format. The other codecs offered for .mts output (H.265, MPEG-2, Xvid, DivX) are not standard AVCHD and may not import cleanly into an AVCHD-aware editor.
• Match the audio codec to your project. xconvert defaults MTS audio to AAC, which most editors read fine; if a stricter AVCHD pipeline wants Dolby AC-3, set Audio Codec to AC3. Either way the audio is re-encoded from the source WMA, not copied.
• Do not raise the resolution. If your .asf is standard-definition, leave Video resolution on Keep original (or a preset at or below the source). Scaling an SD clip up to 1080p makes a bigger file with no extra real detail.
• Use a high quality Preset. Because this is a re-encode, start from Very High (Recommended) so the H.264 pass adds as little new loss as possible.

Common Errors and How to Fix Them

• "My editor still rejects the .mts" — confirm the Video Codec was H.264, not H.265 or MPEG-2. Some AVCHD-only import paths accept H.264 .mts only. If it still won't load, your editor likely wants plain MP4 — use ASF to MP4.
• "The output looks soft / no sharper than before" — expected. WMV is already lossy and standard ASF clips are often SD; re-encoding to H.264 cannot add detail, and upscaling does not create it.
• "Audio is missing or wrong after import" — the source WMA was re-encoded. If the project expects Dolby AC-3, set Audio Codec to AC3 and convert again.
• "Conversion fails or the file is silent" — the .asf may be DRM-protected (Windows Media DRM encrypts the stream) or only partially downloaded. A converter cannot decode a protected stream.
• "File is huge" — .mts/AVCHD uses high HD bitrates by design. Lower it with Constant Bitrate or Specific file size, or convert to ASF to MP4 for a much smaller file at similar quality.

When This Doesn't Work — and What to Use Instead

MTS is a narrow target. You should only convert ASF to MTS when something downstream genuinely expects AVCHD — most often a non-linear editor whose project was set up around camcorder footage. For almost everything else, MTS is the wrong format: it is a large, HD-camcorder container with patchy support outside dedicated camcorder and editing software, so general playback, sharing, and uploading all go better as MP4. If your goal is "make this old Windows Media clip play and share everywhere," convert to ASF to MP4 instead, or downsize it later with MTS to MP4. The conversion also cannot proceed on DRM-locked or corrupted .asf files. Going the other direction — pulling an .mts back into a Windows Media workflow — is MTS to ASF.

Frequently Asked Questions

Why would I convert ASF to MTS instead of MP4?

Only one real reason: an editing workflow that expects AVCHD camcorder footage. MTS is the on-camcorder name for AVCHD (H.264 video, AC-3 or LPCM audio in an MPEG transport stream), so some non-linear editors and AVCHD-specific import paths take .mts cleanly while balking at a Windows Media .asf. If you are not feeding an AVCHD-aware editor, MTS has no advantage over MP4 and several downsides — bigger files, narrower playback support — so ASF to MP4 is the better choice for playback, sharing, or uploading.

Will converting to MTS improve my video's quality?

No, and it cannot. ASF almost always holds WMV video, which is already lossy, and many .asf files are standard-definition. Re-encoding to H.264 inside an .mts is a lossy-to-lossy transcode: it re-wraps the picture in the AVCHD format but cannot rebuild detail the original WMV encoder discarded, and it cannot add real resolution by upscaling. The point of this conversion is format compatibility for editing, not a quality upgrade.

What video and audio codec does the MTS output use?

Video is H.264/AVC, the AVCHD standard, and it is the default here — keep it on H.264 for an AVCHD-compatible result. For audio, xconvert defaults the .mts output to AAC, which most editors accept; if your AVCHD project specifically expects Dolby AC-3 (the codec AVCHD camcorders typically record), switch Audio Codec to AC3. In both cases the audio is re-encoded from the source WMA rather than copied straight across.

Should I increase the resolution to 1080p when converting?

No. If your .asf is standard-definition, upscaling it to 1080p produces a larger file with no genuine extra detail — the missing sharpness was never in the source. Leave Video resolution on Keep original, or choose a preset at or below the source resolution. The AVCHD format supports 720p and 1080i HD, but only footage that was HD to begin with benefits from an HD setting.

Why won't my DRM-protected ASF file convert?

Some older Windows Media files carry Windows Media DRM, which encrypts the stream and ties playback to a license bound to the original device or account. A converter cannot legally or technically decode a protected stream, so the job will fail or produce a silent or black result. This is a property of the DRM, not a fault of the format — you would need an unprotected copy from the original source.

How are my uploaded ASF files handled?

Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically a few hours after conversion. There is no sign-up, no watermark, and your files are never shared or made public. In our testing, the practical limit on a large .asf is upload time rather than a per-file size cap.