- modules/Screen_Record/audio_source.jai: WASAPI, in loopback from the default output device
(what the computer plays) and from the default input device (the microphone), asked for as
48 kHz stereo float, which Windows converts any device to; a device that will not convert is
taken as it is when it gives 48 kHz float. Packets carry the time they were heard. A device
lost (unplugged, default changed) is opened again from the new default once a second.
- An audio thread mixes them onto the video's own timeline: the same time 0, less the same
pauses (record_pause now keeps one account of time paused for both threads). A packet within
30 ms of where its source left off follows on exactly; a source that sends nothing is silence,
passed 200 ms late. Each 1024 samples every source has covered become an AAC frame.
- encoder.jai: an AAC stream (FFmpeg's aac, 160 kb/s) beside the video, written from the audio
thread; both threads' packets meet in the file under a lock. The remux keeps it.
- [video] system_audio (true) and microphone (false). capture.json: Audio, AudioSources. A toast
when a source asked for could not be opened.
- record-probe: -audio system|mic|both, the sound read back (length, level), and -sync-test,
which flashes a white square and beeps together every 2 s, then finds both in the file.
- Measured: 20 s, beeps 0-21 ms from their flashes, no drift; both sources mixed, 5-18 ms;
a 6 s pause cuts the same 6 s from sound and video; 3 min, 85 of 90 beeps within 3-24 ms and
-14 ms from first to last, with 5 outliers (53-147 ms) where two beeps went missing. Tests:
an MP4 with sound keeps its AAC stream through the remux into the library (30 checks).
- modules/Screen_Record/wgc_source.jai: the screen through Windows.Graphics.Capture, with
hand-written bindings for its WinRT interfaces (capture item interop, item, free-threaded frame
pool, frame, session 1-3, IDirect3DDxgiInterfaceAccess, IClosable). A small COM handler on
FrameArrived sets an event per frame; when Windows refuses it the pool is polled each
millisecond. The cursor is drawn by Windows; the yellow border is turned off where the system
allows (Windows 11). A screen that changes size makes the pool again. WinRT's own calls are
loaded from combase.dll at run time: runtimeobject.lib names no DLL for #library.
- capture_gpu.jai: what both sources share (the device on the screen's adapter, the region copy,
the staging ring), so each is only "the next image's region into a texture".
- Record_Options.capture: AUTO (Desktop Duplication, else Windows.Graphics.Capture when it says
fall_back), DXGI or WGC. Sources open on the capture thread, as WinRT objects belong to their
apartment; record_start waits for it to say how that went. Record_Options.testing simulates the
two-GPU failure, forces polling, or keeps the border, for record-probe.
- record-probe: -capture auto|dxgi|wgc, -simulate-unsupported, -poll, -border-test with
-keep-border as its control, -cursor-test; DPI awareness set already is no longer reported as
a failure.
- On the RTX 5080 laptop: auto falls back on the simulated failure; WGC records 4K at 60 fps with
nothing dropped; its cursor and the one cursor.jai draws for duplication are the same; the
border is off for an unpackaged app (0 yellow edge pixels, 14,214 with it kept);
WDA_EXCLUDEFROMCAPTURE is respected; polling holds 30 fps. The plan records the results.
- README: Screen_Record's line, which held a carriage return in place of "\r" since 0.1.3.
