CoreTrim formats
Every format, and exactly what CoreTrim does with it.
CoreTrim exports only the media your timeline actually uses — plus the handles you choose — and relinks your Final Cut Pro project to the new, smaller files. The formats below are trimmed without re-encoding (except where noted), so quality is identical to your originals.
Anything not listed here is copied in full and relinked into your trimmed project. You lose the space saving on that file, never the file.
Video — QuickTime & MP4
.mov · .mp4 · .m4v
| Format | How it trims | Precision |
|---|---|---|
| Apple ProRes422 · 422 HQ · 422 LT · 4444 · 4444 XQ · RAW · RAW HQ | Lossless | Frame-exact |
| Avid DNxHD / DNxHR | Lossless | Frame-exact |
| H.264 / AVC | Lossless | Keyframe-aligned |
| HEVC / H.265 | Lossless | Keyframe-aligned |
| MPEG-2 (Long-GOP)Sony XDCAM in QuickTime | Lossless | Keyframe-aligned |
Other video that Final Cut Pro can read is also trimmable by re-encoding to ProRes — offered only with your approval, never automatically.
Video — Professional MXF
.mxf — broadcast & cinema cameras
| Format | How it trims | Precision |
|---|---|---|
| Avid DNxHD / DNxHR | Lossless | Frame-exact |
| Apple ProResMXF-wrapped, e.g. ARRI | Lossless | Frame-exact |
| MPEG-2 (Long-GOP)Sony XDCAM · Canon XF | Lossless | Keyframe-aligned |
| DV / DVCPROMXF-wrapped | Lossless | Frame-exact |
| UncompressedMXF-wrapped | Lossless | Frame-exact |
| PCM audioMXF-wrapped | Lossless | Sample-accurate |
Video — AVCHD / camcorder
.mts · .m2ts
| Format | How it trims | Precision |
|---|---|---|
| MPEG-2 (HDV-era .mts) | Lossless | Keyframe-aligned |
| H.264 (AVCHD) | Copied in full | Not trimmed |
AVCHD camcorder footage is copied rather than trimmed, by design. Its recordings place true random-access frames roughly eight seconds apart, and trimming to anything less exact risks a clip that starts on the wrong frame — so CoreTrim copies these files intact instead. You lose the space saving on that footage, never the footage.
Audio
.wav · .aif · .aiff · .caf · .m4a · .mp3
| Format | How it trims | Precision |
|---|---|---|
| PCMWAV · AIFF · CAF | Lossless | Sample-accurate |
| AAC (M4A) · MP3 | Re-encoded to AAC | Sample-accurate |
What the terms mean
Five words, used precisely, throughout this page
- Lossless
- No re-encoding — the trimmed media is bit-for-bit the same quality as your original.
- Frame-exact
- Trimmed precisely to your edit points.
- Keyframe-aligned
- Long-GOP formats start at the nearest keyframe just before your edit (a fraction of a second). Still lossless, and your clip plays correctly from its exact in-point.
- Sample-accurate
- Audio is trimmed to the exact sample.
- Re-encoded
- Compressed audio is re-encoded to AAC (the only quality-affecting case above).
Cameras that trim
Common cameras & the formats CoreTrim trims from them
| ARRI | ProRes (MXF & QuickTime)ARRIRAW is copied in full |
| Sony | XDCAM MPEG-2 (MXF & QuickTime) · α7 / FX mirrorless H.264 & HEVCX-OCN is copied in full |
| Canon | XF MPEG-2 (MXF) · EOS DSLR & mirrorless H.264 & HEVCCinema RAW Light is copied in full |
| Panasonic | Lumix H.264 & HEVCV-RAW and P2 are copied in full |
| Blackmagic · RED | ProRes (QuickTime)BRAW and REDCODE RAW are copied in full |
| GoPro · DJI · drones · iPhone | H.264 & HEVC |
Timelines & multicam
CoreTrim trims your media however your timeline uses it
| Multicam | By default only the angles your cut actually uses are trimmed — or keep every angle complete for future re-editing, or skip multicam entirely. Your choice, and the projected saving updates as you change it. |
| Compound & synchronized clips | Trimmed — CoreTrim looks inside them, at any nesting depth. |
| Auditions | Every take is trimmed — the one you picked and the alternatives you parked — so you can still switch takes after importing. |
| Connected clips, lanes & transitions | Kept in place — timing, keyframes, markers and split edits are preserved. |
When a clip is copied instead of trimmed
All safe — the clip is copied in full, never altered
- The clip is offline, or CoreTrim doesn't have permission to read it.
- Your timeline already uses the whole clip — there's nothing to trim away.
- It's a still image, or camera RAW from a manufacturer's own format — ARRIRAW, Canon Cinema RAW Light, Sony X-OCN, RED, Blackmagic BRAW, Panasonic V-RAW. These need the manufacturer's own software to open, so CoreTrim copies them untouched. Apple ProRes RAW is the exception — it trims like any other ProRes.
- It's a specialized or unsupported source format, or AVCHD camcorder footage (see above).
And if a file can be neither trimmed nor copied — a damaged or unreadable source — CoreTrim leaves it out of the export and says so plainly in the report, rather than quietly linking your new project back to the original media.
Any format not listed on this page is copied in full and relinked into your trimmed project — intact, never altered, never lost. CoreTrim never modifies your original media. Updated August 2026 · CoreTrim 1.0.3