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Reporting a bug

Most problems are disc-specific, and the disc is usually one nobody else has. What makes a report actionable is saying which build, which disc, and what happened — and, for anything to do with menus or audio tracks, attaching a small file that lets the problem be reproduced without the disc.

Open an issue →

Always include

  • The core version from the OSD — the v0.3.0 260901 line. It is the only thing that identifies a build. On a test build handed out before a release it names the feature instead, like dev-seekrealign 260903; quote whichever you see, exactly.
  • The disc title and region.
  • What happens, and where — does it boot, reach a menu, start the feature?
  • Any on-screen message.
  • Whether it is a physical disc, a decrypted image, or an encrypted image.
  • If it used to work, which version it last worked in.

A DVD keeps its navigation — every menu, button, title, chapter and audio-track assignment — in a handful of small .IFO files, separate from the film itself. On a typical disc they come to well under 100 KB, and they are all that is needed to reproduce:

  • menus that do nothing, jump somewhere wrong, or show LINK FAIL nn
  • the wrong title playing, or the disc not reaching the feature
  • a track that is silent, or the wrong language playing — which track maps to which soundtrack is decided in those same tables, so this is a navigation question even though it sounds like an audio one
  • chapters that are missing or in the wrong place

Download dvd_report.py and run it on a PC against your own rip of the disc. It needs Python 3 and nothing else, and it works on an encrypted rip too — the navigation tables are never encrypted, so no decryption step is involved:

python3 dvd_report.py MY_DISC.iso

It asks a few optional questions, writes a dvdreport-*.zip of around 40–100 KB, and verifies the bundle actually reproduces before telling you it is done. Attach that zip to the issue.

If the problem is specifically about menu buttons or highlights — the wrong button lit, the highlight in the wrong place, a press doing nothing — add --nav-packs so the button positions are captured too:

python3 dvd_report.py MY_DISC.iso --nav-packs

What is in the bundle, and what is not

Only the disc's unencrypted navigation structures: the directory records, the .IFO navigation tables, optionally the data describing menu buttons, and your answers. No video, no audio, and no decryption keys. It is not a copy of the film and cannot be used to watch anything.

That is enforced, not just intended — the tool checks every sector it has gathered and refuses to write a bundle if any of them carries picture or sound, reporting content audit: PASS when it finishes. It stores your image's filename but no other path from your computer. python3 dvd_report.py info <zip> prints back everything a bundle holds, any time.

This route needs a rip on a PC — encrypted or decrypted, either works. If you only ever play physical discs, the next section is for you.

Or make one on the MiSTer itself

Needs MiSTer_DVDcss

New in v0.4.0, and only with the custom Main installed.

While a disc is playing, hold Audio + Subtitle together for two seconds. The player writes a bundle to /media/fat/DVD_reports/ and tells you the filename on screen. Copy it off the SD card and attach it to the issue.

This works for physical discs as well as images, and it needs no PC. It also records something the PC route cannot: the exact point on the disc you were at when you pressed it, which for a menu problem is usually the whole answer.

Holding those two buttons also steps the audio track and the subtitle track once each — that is expected, and pressing them again puts things back.

The bundle it writes also records two things the PC route cannot: the core version, so you never have to read it off the OSD, and the exact point on the disc you were at when you pressed the chord.

Everything else: describe it

Picture and sound problems live in the video stream itself, which is far too large to share, so words are the right tool. What helps most:

Problem Worth saying
Stutter or judder Whether it is a busy scene, and whether it is film or video content
Lip sync out Whether it is wrong from the start or drifts; whether a chapter skip fixes it; your A/V Offset setting
Artefacts or wrong colours Whether it is constant or occasional, and which output — HDMI, analog, CRT
Analog or CRT trouble Your MiSTer.ini video lines, Analog Out mode, and what the display is
Passthrough or receiver trouble The receiver model, the codec, and whether optical or HDMI

Two questions are worth answering for almost any playback problem, because they separate whole classes of cause: does it happen from a cold load, or only after playing a while? And does a chapter skip clear it?

For lip sync in particular, a phone video with sound is genuinely useful — the offset can be measured from it directly.

What is expected to be broken

Interactive DVD games are known-incomplete, so reports about them are welcome but unsurprising. A film or TV disc that misbehaves is the more valuable report. See Compatibility for what is known not to work.