toolversion 2.6Windows, Linux and macOS
JoltCracker
A free C++ jolt cracker that finds cuts in Minecraft videos. It reads the game's tick counter from the way the hunger bar shakes and compares it with the video's own clock. Where the game counted more time than the video shows, footage was removed or sped up.
1,000+ downloads · 2 hours scanned in 59 s · the most trusted jolt cracker out there
Jolt is free and open source. If it helped you, star it on GitHub, it helps other people find it.
What jolt cracking is
Minecraft shakes the icons on its HUD with random numbers it takes from the game's tick counter. The counter starts at 0 when the game opens and goes up 20 times a second, and a tick shakes the icons the same way every time it comes round. That shake is a jolt, and working back from the jolts to the tick is jolt cracking.
The hunger bar jolts once saturation has run out, on ticks that are a multiple of food level × 3 + 1. At 2 hearts or less the hearts jolt on every tick. One jolt fits many ticks, so a jolt cracker pins the tick down with the jolts around it and the time between them.
In a video with no cuts, the tick counter and the video clock go up together. Checking that by hand means stepping through the video a frame at a time and typing every jolt in. JoltCracker reads every jolt in the whole video by itself, cracks the ticks and marks each place where the two clocks part: 2 hours of footage in 59 seconds.
How to use it
On Windows, unzip it and put jolt.exe in a folder of its own, then double click it. On Linux, unzip it and run Jolt-x86_64.AppImage. On a Mac, drag Jolt.app into Applications and open it; the first time, macOS asks you to allow it under System Settings, Privacy & Security, Open Anyway. Drop a video on the window or paste a YouTube link, and press Start.
Jolt needs ffmpeg, and yt-dlp for YouTube links. On Windows, if you do not have them, Jolt offers to download them for you on the first run and keeps them next to jolt.exe. On Linux, install them with your package manager, and on a Mac with Homebrew; the README in the zip has the line to paste. If YouTube refuses the download, save the video yourself and give Jolt the file.
When it finishes, it writes a report page next to the video and opens it in your browser. Every cut is numbered in red on the graph. Click one to see the last frame before it, the first frame after it and how much time is missing. The report is a single html file, so you can send it to anyone as it is.
It still works from a terminal too: jolt.exe "my video.mp4" --open. The guide has every setting and option.
You only download Jolt once. When a newer version is out, Jolt says so when it starts and updates itself if you press OK. On Linux that needs curl and unzip, and the AppImage in a folder you can write to. On a Mac, keep Jolt.app in a folder you can write to, like Applications.
Two things to know
The hunger bar has to be visible, and it only shakes once saturation has run out, so the first minute or so of a run and the time right after eating cannot be checked. At two hearts or less the hearts shake on every tick, and Jolt reads those as well.
If Jolt cannot find the bar, or you only want to check part of a video, the settings for that are in the window.
Questions
Is JoltCracker free?
Yes. It is free and open source, the code is on GitHub. There is no account and nothing to pay for.
How fast is it?
2 hours of footage scanned in 59 seconds. It depends on the processor and the video, and a graphics card can take a share of the decoding.
Does it work with YouTube and Twitch videos?
Yes. Paste the link and Jolt downloads the video before it scans. A video file on your PC works too.
Can it tell if a speedrun or a manhunt was edited?
It shows every place where the game's tick counter and the video's clock disagree, which is what a cut or sped up footage leaves behind. The report has the frames either side of each one, so you can judge it yourself. Parts where neither the hunger bar nor the hearts jolt cannot be checked.
Do I have to read the jolts myself?
No. The scan reads every jolt in the video by itself. If it misses one you can see, Manual at the top of the window cracks a jolt code typed in by hand.
What about videos that show more than one player?
Jolt finds every hunger bar in the video, even when another player's game is drawn at a different size, and treats each player's screen as its own game.
Is it safe to run?
The Windows build is not signed, so Windows warns the first time. Click More info, then Run anyway. The source is on GitHub and the sha256 of jolt.exe is at the bottom of this page.
Versions
Version 2.6
- Games left open for days. When 20 or more jolts fit no tick in the 24 hours Jolt looks through, it looks through a whole week by itself, with no second scan. A 23 minute run from a game that had been open for 26 hours went from no readings to 485.
- The report counts heart jolts and hunger jolts apart, with the total under them: at the top of the page, on each reading and in the summary at the end of a scan.
- Opened without unzipping. Windows runs a program opened from inside a zip out of a temp folder and deletes what it saves there, like ffmpeg and downloaded videos. Jolt now says so and can put itself in Downloads\Jolt and start from there.
- When an update fails on Linux or a Mac, the log says why and the download page opens.
Version 2.5
- Low health in the dark. When the empty hearts are too faint to make out, Jolt follows the hearts it can see from one tick to the next, even a single red one. On a 2.2 hour manhunt spent at half a heart in a cave, the first nine minutes have 4,087 readings where 2.4 had 48, all on the right tick, and the stretch of almost six minutes with none is gone.
- Hunger jolts at low health are read when only 6 or 7 shanks can be made out, as long as they come at the time the food level says.
- Delete downloaded videos, a new tick next to Read every frame. Once the report is written, the video Jolt downloaded from a link is deleted. A file you picked yourself is never touched, and the download stays when a scan is stopped or fails. Off unless you tick it. In a terminal it is --delete-download.
- When the window is too narrow for all four ticks, they wrap onto a second row.
Version 2.4
- Faster scans, with exactly the same results as 2.3. Jolt's own work on each frame takes half the time it did, so more of the processor goes to decoding: a 44 minute video with 132 cuts went from 67 to 60 seconds.
- Videos that show more than one player's screen are much faster. Each frame is decoded once for all the screens instead of once per screen: a 2.6 hour video with two screens went from 4 min 21 s to 2 min 36 s, one with three screens from 54 to 42 seconds.
- Saving the frames around each cut is about a quarter faster, and long videos start reading sooner: listing the frames of a 4 hour video went from 7 seconds to 1.5.
- Intel graphics take a bigger share of the decoding. The chip cuts the hunger bar's strip out of each frame itself and sends back only that, three times as many frames as before.
- On a Mac the window is sharp on Retina screens, Browse opens the Finder's own panel, and downloaded videos go to Jolt's folder instead of wherever the app was started from.
- Jolt on Linux updates itself from now on, like on Windows and the Mac. When yt-dlp is too old for Jolt it says so and how to update it.
Version 2.3
- Jolt runs on Linux now, and the window there is the same as on Windows down to the pixel.
- Better heart detection. For about a second after taking damage or healing the hearts blink white, and Jolt used to lose those ticks. It reads them now: on a 48 minute video the heart jolts it missed at low health went from 188 to 107, with the same cuts found.
- Faster scans. Finding the hunger bar and saving the frames either side of each cut both take less time.
- Manual, at the top of the window: when the scan misses a jolt you can see in the video, type its code and Jolt finds the tick.
- Sharper text in the window, with no coloured edges around the letters.
Version 2.2
- Videos that cut to another player's screen are read in full. When that player's game is drawn at a different size, their hunger bar sits in another place, and Jolt used to see nothing there. It now finds every hunger bar in the video and reads them all.
- Each player's screen counts as its own game. A cut to another player is listed as a change of screen, not as missing footage.
- What Jolt finds on the main screen is exactly what 2.1 found.
Version 2.1
- A small fix for heart detection: hearts that are low for less than a second, like the moment before a death, are read now.
- Jolt tells you when a newer version is out and updates itself if you let it, with nothing to download by hand.
- The version is shown at the bottom of the window and of every report.
Version 2
- A window, so you do not need a terminal. Every setting is in it, and what you set is remembered.
- Your graphics card can take a share of the decoding: NVIDIA through CUDA, AMD and Intel through Direct3D 11. It can make a scan faster or slower depending on the PC. What the scan finds stays the same, a card is only used after it gave the exact frames the processor gives.
- Matching the jolts to ticks is more than ten times faster.
- When something goes wrong, Jolt says what and how to fix it, with a code you can pass on. Check this PC, top right in the window, tests everything Jolt needs.
- File and folder names in any alphabet work.
Version 1
- The first release: reads the hunger bar and the hearts from a video file or a YouTube link and writes the report page.
For reversers
For the more technically inclined, here is the PDB that goes with this build (2.6 MB). The sha256 of jolt.exe is 723355c466e0cc261f73eee652aec4c1269678b3d7ce32e250315d68ec40ec52.