WebM and Matroska files

macOS won’t open a WebM or MKV file directly, so Frame Job copies its video and sound into a QuickTime movie the first time you bring one in. Nothing is re-encoded, so no quality is lost, and your original stays where it is.

Menu: File ▸ Add Media…File ▸ Open…
Keys: ⇧⌘I⌘O
Where: Drag to the Media tab
Agent tools: import_mediaopen_projectrelink_media

How a file is rewrapped

Rewrapping means moving a file’s video and sound streams into a different container without changing them. Add, open or relink the file as you would any other. There’s no question to answer: the copy starts by itself, and the clip then plays from the copy.

Frame Job recognises these files by what’s inside them, not by their name, so a Matroska file with the wrong extension still imports when you drop it on the Media tab, unless that extension is a picture’s or .cube.

Stream	What the copy carries
Video	VP9, AV1, H.264 or HEVC
Sound	Opus, Vorbis or AAC

Only the first video track and the first audio track are copied. Any other track, such as a second language or subtitles, stays behind in the original.

If the end of the file is damaged or cut short, the copy holds everything up to that point.

Some video can’t come in because this Mac can’t decode it: VP8, AV1 on a Mac without a hardware decoder, and VP9 Profile 1 or 3. Nothing is copied, and the alert says why. See Codecs this Mac can’t decode.

The name in the Media tab

The media keeps the original’s name. Hover over its row in the Media tab and the tooltip gives the original’s path and says the file was copied into Frame Job’s Rewrapped folder.

The Copying Movie window

A copy that takes more than a second shows a small Copying Movie window, with a progress bar and how much has been copied, such as “412 MB of 1.2 GB”. It reads “Reading the file…” until the copy starts.

Choose Cancel to stop. The copy stops, nothing is added, no alert appears and no partial file is left behind. If you were opening the file with File ▸ Open…, no project opens. If you were adding several files, the others carry on.

The window never takes the keyboard from a Frame Job window, so you can keep editing while it runs. Copies happen one at a time.

Free space

Before copying, Frame Job checks that the disk has room. If it doesn’t, nothing is copied and the alert says what’s needed:

Not enough free space to open file: its video and sound need about size on “volume”, which has size free. Nothing was copied.

If Frame Job can’t read how much space the volume has, the copy goes ahead.

The Rewrapped folder

Copies live in ~/Library/Application Support/Frame Job/Rewrapped/, which all your projects share. Importing the same file again uses its copy instead of making another, even in a different project. If the original has changed, Frame Job makes a new copy.

Frame Job doesn’t clear this folder, so copies pile up. You can clear it yourself:

WebM and MKV copies are made again the next time a project that uses them opens, as long as the original is still there.
ffmpeg conversions live here too, and they aren’t made again. Their media stays missing until you relink it.

Consolidate Media copies the movie, not the WebM, into the package. The row’s tooltip then says it was copied into this project’s package.

Streams the copy can’t carry

If a stream is in a codec the copy can’t carry, the file isn’t added, and an alert names the stream, for example:

file has FLAC audio, which Frame Job cannot copy out of a WebM or Matroska file.

This applies to FLAC, MP3, MP2, AC-3, E-AC-3, DTS, TrueHD and PCM sound, Vorbis whose headers can’t be read, and MPEG-2, MPEG-4 Part 2, Theora and ProRes video. A codec without a familiar name appears under its Matroska codec ID. A compressed or encrypted track stops the import the same way: “file has a compressed or encrypted video track, which Frame Job cannot copy out of a WebM or Matroska file.”

If you have ffmpeg installed, Frame Job then offers to help. See Convert files with ffmpeg. Without it, the file isn’t added.

Colour is kept

The copy keeps the colour the file states: HLG, HDR10 (PQ), or a BT.709, BT.601 or BT.2020 SDR picture. Frame Job reads it from the file’s colour information or, for VP9, from the video itself. HDR10 metadata carries over.

A file that states no colour is shown as macOS reads it.

If a copy goes missing

If a copy is deleted or moved to the Trash, the project makes it again from the original the next time it opens. The Copying Movie window shows as usual.

This needs the original to be in place and still be a WebM or Matroska file. If that copy is cancelled or fails, a deleted copy shows as missing, with a slate, the missing badge and Relink…, and a copy in the Trash goes on playing from the Trash. The next open tries again.

With an agent

An agent’s import shows no window and waits for the copy to finish. import_media gives the copy as path and the file you asked for as original. If the copy can’t carry a stream, an agent doesn’t get the ffmpeg question: see Convert files with ffmpeg.