F4V to MTS Converter

Convert F4V to MTS: What This Tutorial Covers

This walks through turning an F4V — Adobe's MP4-based "Flash MP4" container — into an MTS file, the AVCHD stream that HD camcorders and AVCHD editing projects expect. It is a narrow, specific job, so before the steps it is worth being clear about one thing: if your goal is just to play the clip, MTS is the wrong target and F4V to MP4 is the natural move, because F4V is already built on the same container as MP4. MTS is the right choice only when something downstream genuinely wants an AVCHD-style file.

How to Convert F4V to MTS

1. Upload Your F4V File: Drag and drop your .f4v file onto the page, or click "+ Add Files" to browse. Several files queue and run with the same settings.
2. Confirm the Video Codec: Open "Show All Options." MTS is preselected with H.264 video and AAC audio. H.264 is the codec AVCHD is built on, so leaving it is the AVCHD-friendly choice; you can switch audio to AC3 (Dolby Digital) if your editor or player expects the classic AVCHD soundtrack.
3. Set Resolution or Trim (Optional): Use Video resolution to scale with a preset (1080p, 720p) or Width x Height, and Trim with a Time Range to export only part of the clip. Keep within 1920×1080 to stay inside what AVCHD hardware accepts.
4. Convert and Download: Click "Convert" and save your .mts file individually or as a ZIP. No sign-up, no watermark.

Walk-through: Why This Is a Re-encode, Not a Re-wrap

Converting F4V to MP4 can be a light re-wrap, because both are the ISO base media file format — the streams are lifted out and dropped into the new container untouched. F4V to MTS is different. MTS wraps video in an MPEG-2 Transport Stream (the muxing AVCHD and broadcast use), which is a different container family from F4V's ISO base media. So even though both formats typically carry H.264, this pipeline decodes and re-encodes the video into a transport stream rather than copying it. Generation loss is real but small when you keep the settings matched to the source.

To keep that loss minimal:

• Leave the Preset on Very High (Recommended). It targets a high-quality encode rather than a small file, which is what you want when the source is already compressed H.264.
• Match the resolution to the source. Upscaling a 720p F4V to 1080p wastes bitrate without adding detail; pick the Preset Resolution that equals the original.
• Keep audio at AAC unless told otherwise. AAC carries through cleanly. Switch to AC3 only when a specific AVCHD workflow or player insists on Dolby Digital.

Common Errors and How to Fix Them

• "The MTS won't import into my camcorder" — true AVCHD on a camera card lives in a strict folder structure (AVCHD/BDMV/STREAM/) with index files, not a loose .mts. A converted stream plays in editors and players but is not a card-ready AVCHD volume; copying it back onto a camcorder's card rarely works.
• "File is much larger than the F4V" — AVCHD-style H.264 in a transport stream is less space-efficient than a web-tuned MP4. A bigger output is expected; lower the Preset or set a Specific file size if you need it smaller.
• "Output is interlaced-looking or judders" — AVCHD historically uses interlaced fields (60i/50i). If the source is progressive and the player shows combing, this is a field-order mismatch in playback, not a conversion fault — play it in a deinterlacing player like VLC.
• "No audio in an editor" — some editors expect AC3 in AVCHD files; if AAC plays nowhere, re-run with the Audio Codec set to AC3.

When This Doesn't Work

If the F4V is DRM-protected or partially corrupted, it may fail to decode and no container change will recover it. And if your real aim is editing or sharing rather than feeding an AVCHD-specific pipeline, MTS makes the file bigger and harder to handle for no benefit — F4V to MP4 keeps it small and universally playable, and MTS to MP4 is the way back out if you later regret the AVCHD detour. To go the other direction entirely, see the reverse tool, MTS to F4V.

Frequently Asked Questions

Why convert a Flash-era F4V to MTS at all?

It is a niche move, and worth doing only for a specific reason: you want a Flash-era clip inside an AVCHD-style editing project or a workflow that expects .mts. Adobe Flash Player reached end of life on 31 December 2020 and was blocked from running on 12 January 2021, so F4V is an orphaned container that should be modernized while tools still read it — but for most people the destination is MP4, not MTS. AVCHD (the MTS family) was introduced in 2006 by Sony and Panasonic for HD camcorders, and it carries H.264 video with Dolby AC-3 or LPCM audio. Pick MTS when that ecosystem is the target; otherwise use F4V to MP4.

Will I lose quality going from F4V to MTS?

A little, because this is a re-encode rather than a stream copy. F4V usually holds H.264 inside an ISO base media container, and MTS uses an MPEG-2 transport stream — a different wrapper — so the video is decoded and re-encoded instead of being lifted over intact. The loss is small when you keep the Preset on Very High and match the source resolution, since you are re-encoding already-compressed H.264 at high quality. It is not lossless, but at matched settings the difference is hard to see.

Does the MTS keep the audio from my F4V?

Yes. The AAC track in a typical F4V re-encodes into the MTS, and the converter keeps audio on AAC by default. If your AVCHD editor or player specifically expects Dolby Digital, open "Show All Options" and switch the Audio Codec to AC3, which is the classic AVCHD soundtrack codec. For everyday playback AAC is fine and slightly more efficient.

Can I put the converted MTS back onto my camcorder's SD card?

Usually not. A real AVCHD recording is more than a .mts file — it is a whole folder structure (AVCHD/BDMV/STREAM/) with playlist and index files that the camera writes and reads. A converted stream is a valid MTS for editors and media players, but dropping it onto a camcorder's card does not rebuild that AVCHD volume, so the camera typically will not recognize it. Treat the output as an editing/playback file, not a camera-ingest file.

Should I just use MP4 instead of MTS?

For most goals, yes. F4V is already based on the MP4 container, so F4V to MP4 is the lighter, smaller, more universally playable conversion — MP4 plays in Chrome, Firefox, Edge, and Safari and on every phone and TV, while MTS is tuned for camcorder and Blu-ray ecosystems and tends to produce larger files. Choose MTS only when an AVCHD editing project or device specifically needs that format. In our testing, the same F4V re-encoded to MTS came out noticeably larger than the equivalent MP4 at matched quality, which is expected for AVCHD-style transport-stream H.264.

How are my files handled, and how long are they kept?

Your F4V is uploaded over an encrypted (TLS) connection, processed on our servers, and then deleted automatically a few hours after conversion. There is no sign-up, no watermark on the output, and your files are never shared or made public. On a big batch the practical limit is upload time rather than a per-file cap, so trimming just the section you need with the Trim controls before converting uploads far less.