Concat Files

Concat 0.2.5

The release where the picture pipeline moves onto the GPU end to end. Every picture effect, transition and colour tool is now a shader drawn in linear light; HDR footage keeps its light from the file through to an HDR export; a Scopes pane reads the picture; and a phone gets an editor of its own instead of a shrunken desktop. It is also the first release the app can update itself from: Settings › Version lists every release from this one on and installs the one you pick.

Colour and HDR

• A timeline has a colour: SDR (Rec. 709), HDR (HLG) or HDR (PQ), set in the Modify sheet. The first HDR clip dropped on an SDR timeline turns it HLG in the same undo step, and a notice says where to set it back.
• HDR clips - an iPhone's HLG, HDR10's PQ - are decoded at ten bits and converted on the GPU. 4K iPhone HLG previews about five times faster than in 0.2.4, where the CPU tone-mapped every frame.
• On an HDR timeline the clips keep their light above white. The monitor shows it tone-mapped for now; a true HDR preview is next.
• An HDR timeline exports as HDR - HEVC or AV1, ten bits, BT.2020 with HLG or PQ, a PQ file carrying its mastering-display, MaxCLL and MaxFALL metadata - or as tone-mapped SDR, chosen on a Colour row of the export sheet. The API takes hdr too.
• A proxy of an HDR file stays HDR (HEVC, ten bits), so a paused HDR timeline matches the original. The tone-mapped proxies earlier builds wrote of HDR files are made again.
• A Scopes pane: waveform, RGB parade, vectorscope and histogram, counted on the GPU from the picture before anything is clipped. It is in the pane switcher and docks like the others, scaled in percent on an SDR timeline and in nits on an HDR one.
• Adjust works in light. Exposure is in true stops, contrast is in stops about middle grey, white balance is a proper chromatic adaptation, and a highlight past white is carried on rather than clipped.
• Colour wheels (lift, gamma, gain) and RGB and luma curves, as sections of the Adjust tab and as Color Wheels and Curves effects for an adjustment layer. A wheel can be keyframed.
• Contrast, Saturation and White Balance as effects of their own.
• Import LUT reads a .cube saved with a byte-order mark and DaVinci Resolve's LUT_3D_INPUT_RANGE (#208, by theworker02). Tables are kept in float, and one named for ACEScct is read in log, so a graded sky does not band.

Effects

• Every picture effect and transition is drawn by its own shader on the GPU, in linear light. The FFmpeg chains for pictures are gone, and so is the CPU compositor: a machine without a GPU draws the same picture on a software adapter. Sound effects keep their FFmpeg chains.
• New: Chroma Key with spill suppression, Luma Key, Zoom Blur, Motion Blur with an angle, Color Wheels, Curves, Contrast, Saturation, White Balance and Exposure.
• Gaussian Blur is two to four times faster and no longer bleeds colour out of transparent pixels; glows and blooms draw at a quarter of the layer; Fisheye no longer leaves black holes at the edges.
• The effect cards in the library are drawn by each effect's own shader, so a card shows what the effect does. Before, nine effects had no preview and sixteen showed another effect's.
• Grain and glitch effects are the same on every GPU and in an export.
• Green Screen and Blue Screen open as Chroma Key keyed to that colour, and Box Blur as a Gaussian Blur of the same spread. The other old-format effects are retired; see Changes to note.

Compositing and playback

• The compositor blends in linear light at half-float precision: opacity, dissolves, fades, Screen and Add behave as light does, as in Resolve and Final Cut. A picture with nothing on it comes out exactly as it went in.
• Fades to black or white and wipes are drawn in the monitor as the export draws them. Before, the monitor showed a dissolve for a wipe and nothing for a fade.
• A packaged transition is drawn whole on the GPU, with no round trip through memory, and the GPU keeps the frames it uploaded, so a scrub back finds them there.
• Each stream is decoded by whichever of the CPU and the chip is faster for it: 8-bit H.264 on the CPU, everything else on the device. Hardware decode is on by default on Windows and Android now.

Phone

• Android and iOS get an editor shell of their own: the monitor over lanes that slide under a centred playhead, Play under the thumb, and a bar of tools that opens the inspector and the library as sheets over the lanes.
• The start screen keeps its heading clear of the top edge, and New project is a row in the accent colour.
• The Settings page column starts narrow on a phone, scrolls under a finger and drops the Remote page; on a desk it can be dragged to size.
• A ProMotion iPhone animates at 120 Hz.

Editing

• The playhead can follow a trimmed edge, so the monitor shows the frame the cut lands on: a toggle on the tray beside the hand tool, off by default (#194, by Raphael Bernardo).
• Reverse writes the clip's span backwards into the project's cache, sound included, so a reversed clip plays like any other. Freeze, Reverse, Mirror and a new Rotate - a quarter turn clockwise, keyable - sit behind one mark on the tray.
• A title can be set in any font on the machine, or in one of your own, imported from the Text inspector and kept for every project.
• Eleven frame rates to pick from on the launch sheet and the project sheet alike, 10 to 60 with the NTSC rates as exact fractions, plus a typed rate and a typed frame size up to 8192 (#199). A 23.976 project no longer opens the project sheet on 30 fps.
• "Render the sound as a file" is Export Audio: a save dialog asks where the file goes, and it comes into Media, selected.

Export

• A constant-bitrate export gets its bitrate: H.264 holds it, and a CBR HEVC export through libx265 no longer fails to open (#104).
• The export draws on the window's GPU device. On Windows laptops with NVIDIA chips, pressing Export could take the app down at the first frame (#202). The log names the adapter and API an export drew on.

Settings and updates

• Settings › Version says which release this is, checks GitHub for a newer one, and lists every stable release from 0.2.5 on. Install downloads the package for this machine, checks its SHA-256 and puts it in place: the installer runs on Windows, the app bundle is replaced on macOS, an AppImage is written over itself, and a .deb, .rpm or pacman package opens in the desktop's installer. Flatpaks and phones are told why the button is off.
• Speech voices run on CoreML on every Mac and fall back to the CPU on their own; the Engine switch is gone. Chatterbox's first load takes about eleven seconds longer per run while CoreML compiles it.
• The Timeline shortcuts section is gone: J no longer flips a clip. Flipping is on the inspector and the clip menu's Mirror.

Fixes

• Delete on a right-click menu over several selected clips left an empty menu standing (#160).
• The Captions and Speech sheets lose the stray note in their header's corner (#152).
• On Windows the launch sheet's Location came up empty, and a folder chosen with Choose... did not show (#203).
• The Traditional Chinese locale is revised (by Peter Dave Hello).

Changes to note

• Old-format effects are retired. Fifty-six built-in picture effects with no GPU twin are gone; a project that used one opens with a notice naming them and keeps the link, marked not installed. A picture effect package of your own written for format 1, or as an FFmpeg chain, is refused at load with a message saying why. Sound packages are unaffected.
• Exposure is in true stops. A project that pushed Exposure in an earlier release looks less pushed in this one.
• Dissolves, and the mixes inside spins, zooms and glitches, are brighter at the middle, as light is.
• Hardware decode is on by default on Windows and Android, and the Decoding switch is gone from Settings.
• The new Concat mark replaces the cat in every icon.
• Under the hood: Slint 1.18, wgpu 30, and locales keyed by ids rather than by the English (see TRANSLATING.md). The developer docs and the roadmap now live at https://concatenate.pages.dev.

Download

A self-contained build for every platform Concat ships on.

SHA256SUMS lists each file's checksum.