Recording a Game

Since 1.33, ArcadeDMD records every game you play. One game, played normally, is enough to tune a game without the cabinet. Its file is fixed from the recording, the game is replayed in the HD scene to check every moment, and the recording is kept as a test so that nothing breaks later.

What is recorded

1. The values read, with their time, to runtime\captures\<game>-<date>.log. A few hundred KB for a match, with MAME as with RetroArch. Every coin press is in it too.
2. The whole memory of the game (RetroArch), four times a second as compressed differences, to runtime\captures\<game>-<date>.ram. A few MB for ten minutes. It shows where the game keeps what is not read yet, the life of a boss, the kind of a vehicle.
3. Screenshots asked of RetroArch (its SCREENSHOT network command) at the first read, every two seconds while somebody plays, and at once when a life, a mission, a vehicle or one of the game's flags changes. They land in RetroArch's screenshot folder, the time in their name.
4. The marker. A coin button held a good second during the game writes marker n in the capture with its time, takes a screenshot and adds a line to the log. Use it to say "here" when something to look at happens.

Settings

Where	Setting
top of config.json	"capture", "all" (every game, the default), "fights" (the fighting games only) or "off"
retroarch section	"ram_dump": {"enabled": true, "every": 0.25}
retroarch section	"screenshots": {"enabled": true, "every": 2.0, "dir": ""}. Set "dir" to RetroArch's screenshot folder (Settings, Directory, Screenshots) and the log says whether the first picture appeared

In RetroArch, turn off the screenshot notification and flash (Settings, On-Screen Display, On-Screen Notifications). Also turn off "GPU Screenshot" (Settings, Video, Output, an advanced setting), otherwise the pictures come out with the CRT shader at full size, 3 MB each, instead of the game's own 304 x 224.

Sending a game

For a game that is not tuned yet, or one that misbehaves, play a normal game of five to ten minutes. For a fighting game, a match is enough, two rounds won, one lost, a super move. For a Metal Slug, up to the first boss, with a few grenades, a life lost and a vehicle.

Then zip and attach to a GitHub issue.

• the .log and the .ram of the game from runtime\captures
• the zip of the screenshots
• runtime\arcadedmd.log

Tools for the curious

• python tools\replay_capture.py runtime\captures\<file> prints what the HD screen showed second by second, --frames 30,47 draws it at those seconds.
• python tools\ram_diff.py <file.ram> --down 120 160 lists the memory words that only go down between two moments (a life), --watch 0x1012AA follows one, --diff 118 121 shows what changed.

The recordings already received are kept in tests\captures and replayed as tests.