mcap.exe FILE, with FILE first (as Explorer's Open with passes it), opens an .mcap, image, video or
.snagx (app/open_file.jai). With no mcap running, the app starts as usual: an .mcap in the library
opens in the Capture window, anything else in the Opened File window, which says where the library
has it already (by its hash in .import-index) or imports it into the library folder typed or chosen.
With mcap running, a second window opens in view mode: the file alone, with Import, and Open in mcap
/ Show in mcap, which hand it to the running copy (a new Open_File message) and close the view. The
library is not loaded or watched, no model loads, and it has no tray icon, no global hotkeys, and
writes no settings or layout.
Import takes a single file as its source too (and -import FILE DEST); an .mcap is copied in as it is,
while a folder's import still skips them. -open-import DEST imports the opened file as its Import
button does, then exits.
-h and --help open a Command Line window listing the options, also toggled from the Debug Panel; with
mcap running, that one comes forward with it (a Show_Help message).
Thumbnails: the "First preview shown" log line, put between creating a preview's texture and its
else, had every preview after the first marked failed. Once its texture was released (scrolled far
away, or the switch from WARP to the GPU at startup) it was never decoded again and showed "Cannot
read".
The catalog is kept in .catalog-cache in the library, each entry with the size and modified time of
the file it was read from; a start takes the entries whose file is unchanged from it and reads only
the rest. It is saved once the catalog is complete and has changed (at most every 30 s) and at
shutdown. After a reboot the catalog was complete 145 ms after launch, against 3.5 s reading every
file.
The catalog loads on the background Thread_Group, every worker of it, instead of the four preview
workers. rpmalloc (modules/Default_Allocator, 2.0.1-jai.16) takes the place of Jai's single locked
heap: entries from the cache 380 -> 50 ms, and reading the files now scales with threads.
thread_idle is called where workers idle. check_targets.jai checks other OSes with Jai's own
allocator, as rpmalloc runs at compile time with the target's OS layer.
-cold drops the library from the system's file cache first; -no-catalog-cache and -catalog-threads N
are for measuring. [startup] log lines time the listing, the first frame, the cache, the first
preview and the complete catalog.
- src/backends/unix_sdl3_gpu3.jai (macOS and Linux) brought all of ImGui into the app's scope,
where ImGui.Image collided with modules/Image_Decode's Image struct: both builds have failed
since 0.0.8 brought in Image_Decode. It now uses ImGui except Image, with a note to keep that
when the file is generated again.
- app.record_region (-record-region) was a Windows RECT in the shared App struct, from 0.1.6;
it and its parsing are Windows only now.
- jai check_targets.jai - linux passes. The macOS check needs a Mac: macOS shares the same
backend file and App struct, so both breaks applied there too.
- src/app/screen_record_win32.jai: while recording, a red frame just outside the region (one
window shaped by a window region, clicks let through) and a toolbar beside it (below the
region at its right, else above, else inside a whole screen's top right): a blinking dot,
the time less time paused, the size, frames dropped and screen losses, and Pause/Resume,
Stop, and Discard, confirmed in the toolbar itself ("Yes, discard / No"). GDI windows that
never take the focus, kept out of every capture (WDA_EXCLUDEFROMCAPTURE). Buttons only ask;
screen_record_frame acts on the next frame. On the shutdown thread they are hidden, not
destroyed.
- modules/Screen_Record: record_pause; while paused the source is drained but nothing is sent,
and frames' times leave the pause out, so the video has no gap. Record_Stats.paused_seconds;
Record_Testing.LOSE_DUPLICATION loses Desktop Duplication every 3 s.
- Recordings left in %TEMP%/mcap by a crash are offered at startup: into the library (no window
known; size from its frames, date from its name), deleted, or later.
- [video] in settings.config: fps (1-120, 30), cursor (true), capture (auto, dxgi, wgc); written
into existing files on the next launch.
- The Win32 GDI bindings move to src/base/platform/win32_gdi_bindings.jai, shared by the overlay
and the toolbar.
- -record-region X Y W H and -record-ui-visible for -record; -pause SECONDS and -lose for
record-probe. capture.json's Paused.
- Checked: the toolbar is not in a whole-screen recording's frame; a 10 s pause leaves a 6.2 s
video of a 16 s run at a steady 30 fps (DXGI and WGC); 3 simulated losses in 10 s recover with
no gap. Tests: a leftover's date and its write (22 checks in the recording group); all pass.
- Fixed on the way: a recording's path repeated the temporary folder ("%1" is the first argument).
- record_region, a new [global_hotkeys] action on Ctrl-PrintScreen (Windows only; none on
macOS): starts a recording, or stops the one running.
- The overlay's video mode (screen_capture_win32.jai): red outline and magnifier; the drag held
to the screen it began on; under 240 x 180 (record_size_allowed, in Screen_Record) the outline
is dashed, the label gives the minimum, and letting go takes nothing; a click or Enter takes
the whole screen; no pixels copied. With immediate, no overlay at all: the screen under the
cursor, for PrintScreen while recording.
- src/app/screen_record.jai: records with modules/Screen_Record to %TEMP%/mcap at 30 fps; a
recording that stops by itself keeps what it has, as does quitting (the shutdown step stops it).
The MP4 goes into the library through the stills' jobs: a video .mcap in Screen Captures, the
MP4 its original, a frame of it its rendered image, metadata.json as a still's, capture.json
with Duration, FrameRate, VideoCodec, PosterTime, Encoder, Capture and DroppedFrames; the MP4 is
deleted once it is in. The catalog reads a video's keys from capture.json too.
- The capture thread makes itself aware of each monitor's DPI: ImGui makes only the main thread
aware, and Desktop Duplication refused the app's capture thread with DXGI_ERROR_UNSUPPORTED
(the fallback recorded with Windows.Graphics.Capture, and the log said so).
- -record SECONDS records the screen under the cursor, puts it in the library and exits;
-record-quit quits while recording instead. Both pass on a scratch library.
- Tests: a "screen recording" group (the size rule; an MP4 from the module's encoder written as a
recording reads back, and the catalog takes it as a video). The segment overlay test no longer
depends on the colours chosen in the app's own data folder.
- README, the format's README and the plan describe it.
- capture_region, a new [global_hotkeys] action, on PrintScreen by default (Windows only; none on
macOS). Existing settings files get the line appended on the next launch. When the key cannot be
registered, the log names Snagit and Windows' "Print screen opens screen capture" setting.
- app/screen_capture_win32.jai: every screen copied the moment the key fires (BitBlt with
CAPTUREBLT over the virtual desktop), shown darkened in a topmost GDI window in a modal loop of its
own, so it works with mcap hidden in the tray. Dragging shows the region bright and outlined; a
magnifier shows the pixels under the cursor with its position or the selection's size; arrow keys
move a pixel (ten with Shift). A click or Enter takes the whole screen under the cursor; Escape,
a right click or losing the focus cancels. Only the parts that change are redrawn.
- app/screen_capture.jai: the region goes on the clipboard (CF_DIB) at once, then a thread writes it
into the library's "Screen Captures" folder as a PNG .mcap: metadata.json with the window under
the region's middle (its title as WindowName, its program's description as AppName) and
capture.json (where on the desktop, the program's path, the hash). mcap then comes to the front
showing it, and OCR, labels and segmentation read it as they read an import.
- A "screen capture" group in the import tests: the file written, its pixels, preview and Capture
Text read back. README and the format's README describe it.
- .library-folders in the library (src/app/library_folders.jai): each library folder's options,
starting with segment: true. Every folder starts off; unknown keys are kept when it is rewritten.
- The Segmentation window (Segments, above the grid): each folder's Segment checkbox, how many of
its images are segmented, and Erase per folder; a button to segment the folders set to segment.
- The segmentation scan (src/app/segment_ui.jai) runs on the OCR thread as its own task, with the
OCR scan's progress, pause and cancel: images only (never videos), not yet segmented, in folders
set to segment. The engine loads with the first scan (2.4 GB of GPU memory). Each image's segs and
mask are stored in one rewrite and its catalog entry loaded again.
- Importing into a folder set to segment segments the new images; the Import window's checkbox is
the folder's setting.
- -segment segments and exits; -erase segments, and -erase all now includes segments.
- The catalog reads each capture's segs (class list hash, segment count). The exit overlay names the
segmentation scan and model. segment_mcap_chunks moved into modules/Segment, shared with
segment-probe. The quoting helpers of Capture_File's text formats are public.
- Tests: .library-folders read and written back (quoted names, unknown keys, versions).
- Import window (and -import SOURCE DEST): every image under a folder (PNG, JPEG, HEIC, AVIF, WebP,
GIF, BMP, TIFF, camera RAW) becomes an .mcap holding the file as it was, a preview turned by its
EXIF orientation, and metadata.json and import.json Capture Text (date from EXIF, the file name or
its time; file name as title; camera as app). .snagx files become the same .mcap SnagitConverter
makes. Duplicates across the whole library are skipped by a hash index (.import-index); videos
and sidecars are skipped; source files are only read.
- modules/Image_Decode: stb_image, then WIC for everything else; EXIF; orientation; previews.
tools/image_probe.jai shows what it reads.
- modules/Snagx (and modules/jaison), copied from SnagitConverter.
- The library is a folder of folders: recursive scan, a folder filter, and a folder: search prefix.
- OCR, the viewer and ocr-bench decode any image format, turned the right way up.
- Rename D:\SnagitIndex to D:\McapIndex.