Trim AVCHD

How to Trim AVCHD Video Online

1. Upload Your AVCHD File: Drag and drop or click "Add Files" to select your camcorder recording. Both .mts (the on-camera filename) and .m2ts (the same stream after import to a computer) are accepted, since AVCHD uses the same MPEG transport stream container in either case. Batch trimming of multiple clips is supported.
2. Set Trim Points: Under "Trim," enter a Start time (default 0) and a Duration (default 10 seconds). Both fields accept plain seconds or HH:MM:SS.sss format down to the millisecond — for example, 00:01:23.500 selects starting at 1 minute 23.5 seconds.
3. Pick a Quality Preset (Optional): The Quality Preset (Highest, Very High, High, Medium, Low, Lowest — default Very High) controls the H.264 re-encode that produces the trimmed clip. Very High keeps the clip visually indistinguishable from the original camcorder source for typical viewing.
4. Adjust Resolution and Trim (Optional, then Run): Keep the original resolution (default), pick a fixed preset (144p through 4320p), or scale by a percentage (e.g. 80%). Click "Trim" — files process in your browser session and download individually or as a ZIP. No sign-up, no watermark.

Why Trim AVCHD Camcorder Clips?

AVCHD ("Advanced Video Coding High Definition") is the HD camcorder format jointly introduced by Sony and Panasonic in 2006, with consumer cameras shipping in spring 2007. It wraps H.264/AVC video and Dolby Digital (AC-3) audio inside an MPEG transport stream — that's why one continuous take comes off the SD card as a single .mts (or sometimes .m2ts after import). Cameras from Sony, Panasonic, Canon, JVC, Hitachi, and Leica all wrote to this format, and bitrates went up to 24 Mbit/s on AVCHD 1.0 and 28 Mbit/s on AVCHD 2.0 Progressive (1080p50/60). Source: Wikipedia: AVCHD.

That bitrate plus long takes makes raw camcorder clips heavy and unwieldy. Trimming is usually the first edit step:

• Pull a single scene out of a long take — A 45-minute recital recorded as one continuous file is 6-8 GB. Trimming to the 4-minute solo you actually want gets you to ~600 MB you can share, archive, or hand to the music teacher.
• Cut camera-on / camera-off junk — Camcorders typically capture a few seconds before you press record-stop and a few seconds of pan-down after. Trimming those off makes the clip ready to publish without opening a full NLE.
• Upload-cap fit for cloud and email — Gmail attachment cap is 25 MB, WeTransfer free 2 GB, iCloud free tier 5 GB total. A trimmed 90-second highlight from an event is small enough to email; the original 45-minute take is not.
• Prep clips for editors that don't open AVCHD natively — Apple's iMovie does not natively open .mts / .m2ts files; many users trim and re-export to MP4 first. See AVCHD to MP4 for the format change after trimming.
• Storage and backup hygiene — A wedding shoot fills a 64 GB card with raw AVCHD. Trimming to keepers before backup recovers tens of GB and shortens upload time to family cloud storage.
• Privacy and selective sharing — Cut the section before the awkward conversation, or the kid running across frame, before sending the clip on. Browser-based trimming means the unwanted footage never leaves your device.

AVCHD Format Quick Reference

Property	AVCHD 1.0	AVCHD 2.0 (Progressive / 3D)
Year introduced	2006 (cameras shipping 2007)	Amended 2011
Container	MPEG transport stream	MPEG transport stream
File extension on card	.mts	.mts
File extension after import	.m2ts	.m2ts
Video codec	H.264 / MPEG-4 AVC, Main or High Profile, Level 4.1	H.264 / AVC, Level 4.2
Max bitrate	24 Mbit/s (18 Mbit/s on DVD media)	28 Mbit/s
Audio codec	Dolby Digital AC-3 (64-640 kbit/s); Linear PCM on pro bodies	Dolby Digital AC-3; LPCM
Top resolution	1920×1080 (interlaced or 24p/25p)	1920×1080 at 50p/60p; stereoscopic 3D
Common manufacturers	Sony, Panasonic, Canon, JVC, Hitachi, Leica	Sony, Panasonic (later models)

.mts vs .m2ts — Are They the Same File?

Question	.mts	.m2ts
Underlying container	MPEG transport stream	MPEG transport stream
Video / audio codec	H.264 + AC-3 (or LPCM)	H.264 + AC-3 (or LPCM)
Where you see it	Direct from camcorder SD card / internal storage	After import via PMB / PlayMemories / Catalyst, or in a Blu-ray STREAM/ folder
Plays in VLC?	Yes	Yes
Plays in iMovie?	Not natively	Not natively
Bit-for-bit identical?	Often the same stream — only the wrapper / extension differs after import	Often the same stream — only the wrapper / extension differs after import

xconvert's trim tool accepts both. If your file came off the camcorder as .m2ts (Panasonic models, AVCHD 2.0 imports, or Blu-ray rips), upload it the same way.

Frequently Asked Questions

Why won't iMovie or Final Cut import my AVCHD .mts file directly?

Apple's consumer apps were built around QuickTime / MOV; AVCHD's MPEG transport stream isn't a native QuickTime container, so the .mts extension is invisible to iMovie's import dialog. The standard fix is to repackage the same H.264 stream into MP4 (which uses the same codec) before editing. Trim first to keep only the section you need, then convert with AVCHD to MP4 or AVCHD to MOV.

How precise can I cut — frame-accurate?

Yes. Both Start and Duration accept HH:MM:SS.sss to millisecond precision (e.g. 00:00:12.083 for the 12.083-second mark, roughly frame 362 at 29.97 fps). Whether the resulting clip is bit-perfect to the original frame depends on GOP alignment (see next question).

Is the trim "lossless" — no re-encode?

xconvert's trim re-encodes through the H.264 pipeline, which keeps quality high but is not bit-identical to the source. AVCHD uses long-GOP H.264, so true zero-re-encode trims are only possible at I-frame (keyframe) boundaries — typically every 0.5-2 seconds depending on camera. If you need frame-accurate cuts at any timecode (the common case), some re-encoding is unavoidable. Set Quality Preset to "Highest" if you want the smallest possible visible difference from the source.

Will my AC-3 audio be preserved?

The trimmed clip retains the full audio track aligned to the new start/end. The audio codec in the output follows the chosen output container; for AVCHD the audio path stays AC-3 / Dolby Digital. Multi-channel surround (5.1) tracks from prosumer Sony / Panasonic bodies remain multi-channel.

Can I batch-trim multiple AVCHD clips with different in / out points?

Yes. Drop in multiple .mts or .m2ts files; each file gets its own Start and Duration fields. Useful when extracting one keeper clip from each of, say, twenty soccer-game takes recorded across an afternoon. Output downloads individually or as a single ZIP.

Do you support 1080p60 / AVCHD Progressive and AVCHD 3D?

Yes — the AVCHD 2.0 amendment (2011) added 1080p50 / 1080p60 modes up to 28 Mbit/s and stereoscopic 3D, and both are H.264 inside the same MPEG transport stream container. The trim tool reads the stream regardless of profile / level. Stereoscopic clips remain stereoscopic in the output.

Should I trim the AVCHD file or just convert to MP4 first and trim that?

If you only need to cut the clip and keep AVCHD, trim here directly — one operation, one output. If you also want a format change (MP4 for editing, MOV for Final Cut, smaller file for sharing), trim first to discard footage you don't need, then convert. That order keeps the conversion fast — re-encoding 90 seconds is far cheaper than re-encoding the full 45-minute take. See AVCHD to MP4 and Compress AVCHD for the follow-up steps.

Why is my trimmed clip a slightly different file size than I expected from "(duration / total) × original size"?

Because AVCHD records at variable bitrate. A 30-second high-motion section (sports, panning shots) carries more bits than a 30-second static-tripod interview. Trimming preserves the actual bits of the kept section, so a "10% duration" trim from the high-motion middle of a take can yield 15-20% of the file size, while the same percentage from a static section yields 5-8%.

Does the trimmed file still play on my camcorder / Blu-ray player?

If the output container, codec profile, and resolution stay within AVCHD spec (H.264 High Profile L4.1, AC-3 audio, ≤ 24 Mbit/s for AVCHD 1.0 devices), most camcorder firmware will play the trimmed .mts back. Older 2007-2009 bodies are stricter — keep Quality Preset at Very High and resolution at original to maximize compatibility. For pure desktop / phone playback, convert to MP4 afterward and you'll get universal compatibility with no spec-policing.