MP4 to AVCHD Converter

How to Convert MP4 to AVCHD Online

1. Upload Your MP4 File: Drag and drop or click "Add Files" to select MP4 sources — phone recordings, screen captures, edited NLE exports, GoPro clips, or pre-encoded H.264 / H.265 masters all work. Batch is supported, so drop in a folder of MP4s at once. The tool also accepts .m4v if that's what your editor wrote.
2. Pick a Quality Preset or CRF: AVCHD locks the video codec to H.264 (the only codec the spec allows) and the audio to AC-3 by default. Choose a Quality Preset (Highest → Lowest), target a percentage of the original size, set an exact file size in MB, or fine-tune with CRF (18 = visually lossless, 23 = default for camcorder playback, 28 = smaller MTS for archival). For Blu-ray-style disc authoring, Highest or CRF 18-20 keeps headroom for a clean master.
3. Set Resolution and Trim (Optional): AVCHD is an HD-only spec — pick a resolution preset (1920×1080, 1280×720, or 1440×1080) or scale by percentage. 4K MP4 sources must downscale to 1080p; AVCHD has no 4K mode. Use the trim section to enter a start time and duration in HH:MM:SS.sss to cut to just the segment you want on disc.
4. Convert and Download: Click Convert. Files process in your browser session — no sign-up, no watermark — and download as MTS / M2TS streams ready to drop into the AVCHD BDMV/STREAM/ folder structure.

Why Convert MP4 to AVCHD?

MP4 is the universal delivery container — the default output of phones, NLEs, screen recorders, and almost every "Export" button on the web. AVCHD (Advanced Video Coding High Definition) is the consumer HD camcorder spec developed by Sony and Panasonic in 2006: H.264 video plus AC-3 audio inside an MPEG-2 Transport Stream (.mts / .m2ts), arranged in a strict BDMV/ directory structure. MP4 and AVCHD often share the same H.264 video codec, but the container, audio codec, and folder structure differ — which is exactly why a conversion is needed for camcorder and disc workflows. The most common reasons to re-encode MP4 down to AVCHD:

• Re-importing edited footage into a Sony or Panasonic camcorder — Sony Handycam, FX-series, and Panasonic HC-X / AG-AC bodies will not re-ingest an MP4 file, even if its H.264 stream is identical to what they originally recorded. They only accept video that matches the AVCHD spec exactly. Converting to AVCHD lets you place an edit back on the camcorder's SD card under PRIVATE/AVCHD/BDMV/STREAM/ for tape-style archival.
• Authoring AVCHD discs that play on any Blu-ray player or PS4 / PS5 — Drop the resulting MTS into BDMV/STREAM/ on a regular DVD-R or BD-R and standalone Blu-ray players from 2008 onward, plus PS4 and PS5, will play the disc like a real Blu-ray. No Blu-ray burner required when the runtime fits a DVD.
• Feeding older AVCHD-only NLEs that reject MP4 — Sony Vegas (pre-13), Pinnacle Studio, and several Panasonic-bundled editors only accept native AVCHD MTS — they reject MP4 input outright, even when the underlying H.264 stream is compliant. Converting to AVCHD first lets the legacy NLE see the footage as a proper AVCHD clip.
• Swapping AAC audio for AC-3 — MP4 almost always carries AAC audio, which AVCHD camcorders and many older Blu-ray players will not decode. The conversion re-encodes the audio to AC-3, the AVCHD default that every consumer device in the chain handles cleanly.
• Sharing footage on TVs without a media server — Burn the BDMV folder to a USB stick, plug into a 2010-or-later Sony, Panasonic, or Sharp TV, and AVCHD plays natively from the disc/USB menu. The same MP4 sometimes plays, but file-system handling and audio support vary by TV model.
• Long-form storage that survives format obsolescence — AVCHD is a published spec from the Blu-ray Disc Association. Storing masters as MTS in BDMV folders means any computer, NAS, or future Blu-ray player will still read them, while MP4 playback depends on whatever codec combination you embedded.

If you want to keep the MP4 wrapper and only swap the codec or trim, use Trim MP4 or Compress MP4 instead — those keep the .mp4 container intact.

MP4 vs AVCHD — Format Comparison

Quality Preset / CRF Quick Guide

Note: AVCHD spec caps peak video bitrate at 24 Mbps for AVCHD 1.0 and 28 Mbps for AVCHD 2.0 (Progressive). If a downstream device rejects the file, drop the bitrate below 24 Mbps.

Frequently Asked Questions

My MP4 is already H.264 — why does it need to be re-encoded for AVCHD?

The video stream may be identical, but the container and audio aren't. AVCHD requires an MPEG-2 Transport Stream wrapper (.mts / .m2ts) and AC-3 audio; MP4 uses an ISO BMFF wrapper and AAC audio. Even an H.264 MP4 will be rejected by Sony / Panasonic camcorders and AVCHD-only NLEs because they parse the container, not just the video stream. The converter rewraps the H.264 video (without re-encoding when possible) and converts AAC to AC-3.

What's the difference between AVCHD, MTS, and M2TS?

They're closely related. MTS is the raw filename extension AVCHD camcorders write directly to SD card. M2TS is the same content used inside the AVCHD BDMV/STREAM/ folder structure on a disc. AVCHD is the overall spec — the folder structure plus the stream format. Our converter outputs the stream that both extensions wrap; pick the .mts or .m2ts variant if you need a specific extension, or stick with AVCHD for the folder-ready file.

What if my MP4 is 4K — can I keep the resolution?

No. AVCHD caps at 1080p (1920×1080 progressive, 1440×1080 interlaced). The converter downscales 4K MP4 sources to 1080p when AVCHD is selected. If you need to keep 4K, output to MP4 or MKV instead.

My MP4 is HEVC / H.265 — will it convert?

Yes. HEVC MP4 sources (the iPhone "High Efficiency" default since iOS 11) decode on input and re-encode to AVCHD-compliant H.264. Expect the output MTS to be 30-50% larger than the source HEVC at the same visible quality, because H.264 is less efficient. Drop the CRF to 25-28 or pick the Low preset to claw the size back.

Will the file work on my Sony or Panasonic camcorder?

If the camcorder supports AVCHD ingest (most Sony Handycam, HDR-CX/PJ, FX, and Panasonic HC-V / HC-X models do), yes — copy the converted MTS file into the PRIVATE/AVCHD/BDMV/STREAM/ folder on the SD card and the camcorder will see it. Older bodies may also need the index files refreshed; some manufacturer utilities rebuild that automatically.

Can I burn the converted file to DVD and play it on a Blu-ray player?

Yes — that's one of AVCHD's main use cases. Place the MTS file inside BDMV/STREAM/ on a regular DVD-R, add the standard BDMV/ index files (most disc-burning apps add these automatically when you select "AVCHD disc"), and any Blu-ray player from 2008 onward, plus PS4 and PS5, will play it as a Blu-ray-style disc — no Blu-ray burner needed.

Will my multiple audio tracks transfer?

Only the primary audio track converts (re-encoded to AC-3, the AVCHD default). MP4s carrying multiple language tracks or commentary tracks will see only the first stream survive — AVCHD consumer devices expect a single primary audio stream. If you need every track preserved, keep the source MP4 or use MKV instead.

Why does AVCHD lock me to H.264?

The AVCHD spec is a strict subset of Blu-ray, written in 2006 when H.264 was the only HD codec consumer hardware decoders supported. Adding H.265 or AV1 would break compatibility with every AVCHD camcorder, Blu-ray player, and PS4 ever made. If you need H.265 inside a more flexible container, output to MP4 or MKV instead.

Does the file include the BDMV folder structure I need for a disc?

The converter outputs the stream file (the .mts content). The surrounding BDMV/INDEX.BDM, BDMV/MOVIEOBJ.BDM, and BDMV/PLAYLIST/00000.MPL index files are generated by your disc-authoring app (multiAVCHD, tsMuxeR, ImgBurn with AVCHD template, or built-in tools in Vegas / EDIUS). Drop the converted .mts into the authoring app's input list and it builds the folder structure for you.