SlopCap 0.1.2

Downloads

File	For
slopcap-windows-x64.zip (27.3 MB)	Windows 10 / 11, 64-bit: slopcap.exe (the whole program in one file, camera drivers inside), a README and the guide (docs/)
slopcap-linux-x64.zip (64.5 MB)	Linux x64, Ubuntu 26.04 or newer: Qt, the camera drivers and their udev rules inside, a launcher, a README and the guide
slopcap-macos-arm64.zip (44.9 MB)	Mac with Apple silicon, macOS 27 or newer: SlopCap.app (Qt and the camera drivers inside), a README and the guide

SHA-256

3902c59f3f99ef5c55fb7ffb35b8f5b8ee441bcf6f66d3e3a8d77ab9fb58233c  slopcap-linux-x64.zip
b0766637bf37f44aac3759624e81e6c3ac2e9ebdef339c5544ce1fb7afa528a0  slopcap-windows-x64.zip
7d4e15ef47990d778b0f0caab6f55730581f11f58efc72221026add1c710c864  slopcap-macos-arm64.zip

SlopCap is free software under the GNU General Public License, version 3. Each zip has LICENSE (SlopCap's) and
licenses/, with the licenses of everything else inside it.

SlopCap isn't signed. Windows warns about an unknown app the first time: More info, then Run anyway. On a Mac,
drag SlopCap.app to Applications and open it; macOS refuses it the first time, so go to System Settings → Privacy &
Security and choose Open Anyway.

What's new in 0.1.2

Much less CPU on Windows, a recording buffer that rides out disk stalls, and fixes to recording lengths and 16-bit
files.

Less CPU on Windows

SlopCap 0.1.1 used about one CPU core at every frame size on a small Windows PC with Intel graphics (Core i5-8500T),
where SharpCap used a fifth of one at 640×480. Two causes:

• Intel's Windows OpenGL driver burns a core waiting for each screen refresh.
• SlopCap redid its display work for every frame the camera delivered.

Measured on that PC with a ZWO ASI585MC, recording 30 s at each size, CPU in cores:

	0.1.1	0.1.2	SharpCap 4.1
3840×2160, 8-bit	1.36	0.85	1.35
1920×1080	1.25	0.39	0.50
1024×768	1.16	0.28	0.30
640×480	1.14	0.28	0.20

(0.1.2's figures are from its release candidate before the last change below, which measured the same.)

What changed:

• The preview no longer waits for the screen's refresh on Windows; it paces itself instead.
• The display work (stretch, white balance, histograms) is done once per shown frame.
• The preview shows 30 frames a second unless you pick 15, 60 or the screen's rate on its toolbar.
• The window is redrawn once per shown frame, not again for each panel that changed in between. While the session
  driving these tests was watching the screen, the rest of the machine worked about 0.8 cores harder beside SlopCap
  than beside SharpCap; with this release that fell to under 0.1, most likely for this reason.
• The live focus score runs 15 times a second off the Focus tab (every frame on it, and during sweeps).

Recordings keep every frame. Focus, collimation and the other tools still work as before.

Recording

• A recording buffer sized for the format: about 8 seconds of frames, at most a quarter of the free memory (1 to
  4 GB). On a 16 GB PC that's about 450 MB at 640×480 and 2 GB at full frame, where 0.1.1 always took 1 GB. A
  filling SSD stalls for hundreds of milliseconds at a time: at full frame the old 1 GB lost frames to those stalls,
  and this one lost none until the SSD was nearly full (when no buffer keeps up).
• A warning before frames are lost: the bottom bar's buffer figure turns orange, then red, as the disk falls
  behind, and SlopCap says so.
• Recording lengths are the capture's own. "Saved N frames (X s)", the .txt file's duration and end, and the
  mid-recording time in the file name (WinJUPOS) used to include the time the disk took to catch up after the camera
  stopped. A 30 s full-frame recording said 36 s and was named up to 3 s late.
• 16-bit SER files say 16 bits. The values were always stored in the top bits of each 16 (a 12-bit camera's
  4095 as 65520), but the header said 12, which some programs read as values running to 4095 only. The .txt file now
  gives the camera's own depth (ADCBits=12). Older 16-bit recordings still say 12; SlopCap's own replay reads both
  kinds correctly.
• The session log gives each recording's CPU use, buffer size and drain time.

Fixes found by running every test on Windows

• Reading a recording that was still being written failed on Windows: the file size came from the directory, which
  Windows doesn't update while the file is open.
• The session log's output wasn't flushed, so a program reading it on Windows saw nothing until SlopCap quit.

Cameras and mounts

As in 0.1.1: ZWO, QHY, Player One, ToupTek and MallinCam cameras, with each vendor's driver inside; mounts through
INDI or SlopCap's own drivers (LX200 and OnStep, Celestron NexStar, Sky-Watcher SynScan and direct, the SynScan app).

Not yet tried on real hardware

• Player One, ToupTek and MallinCam cameras (tested against simulations of their SDKs)
• the built-in mount drivers (tested against simulations of each protocol)
• the Mac app on a screen
• these CPU changes on a Mac or Linux PC with a camera; they were measured on Windows, and the tests pass everywhere

SlopCap 0.1.1

SlopCap 0.1.1: the same program as 0.1.0, now packaged as zips that carry the license, and with a Mac build. SlopCap
is free software under the GNU General Public License, version 3.

Downloads

File	What
slopcap-windows-x64.zip	Windows 10 / 11, 64-bit: slopcap.exe (the whole program in one file, camera drivers inside), a README and the guide (docs/)
slopcap-linux-x64.zip	Linux x64, Ubuntu 26.04 or newer: Qt, the camera drivers and their udev rules inside, a launcher, a README and the guide
slopcap-macos-arm64.zip	Mac with Apple silicon, macOS 27 or newer: SlopCap.app (Qt and the camera drivers inside), a README and the guide

Each zip has LICENSE (SlopCap's, GPL-3.0) and licenses/, with the licenses of everything else inside it: the
camera drivers, Qt and the libraries that come with it, the compiler runtime (Windows) and the IBM Plex fonts.

SlopCap isn't signed. Windows warns about an unknown app the first time: More info, then Run anyway. On a Mac,
drag SlopCap.app to Applications, then the first time right-click it and choose Open, then Open again.

Cameras

ZWO, QHY, Player One, ToupTek and MallinCam, with each vendor's driver inside on all three systems. On Windows the exe
unpacks the driver on first use, and a newer DLL put next to slopcap.exe wins. The camera still needs the vendor's
USB driver on Windows, the one SharpCap uses.

Mounts

Through INDI, or with SlopCap's own drivers: LX200 and OnStep, Celestron NexStar, Sky-Watcher SynScan hand
controllers and direct (EQ6-R, HEQ5, EQ8, AZ-EQ, Star Adventurer GTi), and the SynScan app.

Not yet tried on real hardware

• Player One, ToupTek and MallinCam cameras (tested against simulations of their SDKs; on Windows each SDK loads and
  enumerates)
• the built-in mount drivers (tested against simulations of each protocol)
• the reworked focus sweep (it now follows the focuser and carries on past its range to the peak) at the telescope
• the Mac app on a screen: it's built and its tests pass on a Mac, but it hasn't been used there with a camera

ZWO and QHY capture and the INDI focuser have been used with real equipment, and the ADC tab under the real sky,
where it works well.

Changed since 0.1.0

• Releases are zips only, each with a README, LICENSE and the third-party licenses; there's no separate slopcap.exe
  download any more (it's inside the Windows zip).
• A Mac build.

SHA-256

75b995f59b2be36e9ea148a505f9760e9dfa955858f363ad2972e33210cd921b  slopcap-linux-x64.zip
13e7ac5cc08bf1342c086fcb452912ba2c3f51a0ef977e17e65857fe264f940c  slopcap-windows-x64.zip
4a4fcd3bbb738dd9163b9f0686f545d18ff317fd75e394a0c2febc8735187cfc  slopcap-macos-arm64.zip