libretro / libretro/libretro-database

Sega-CD: incorrect dB match: "Silpheed (USA)" is wrongly identified as "Double Switch (USA)"

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Description

This repros on RetroArch 1.19.1 (stable) for both Windows and Android. This also happens even with CRC-deduping of discs with identical serial numbers is enabled.

The checksum-verified title Silpheed (USA) is found by RetroArch's content importer, and the correct thumbnails are found for it by the online updater... but RetroArch wrongly displays the game's title in the playlist as Double Switch (USA).

Here are the actual checksums (per command-line tools) and serials (per hex editor) of the files I have. All the checksums match the redump dat file, but there's a serial number problem:

  • Silpheed (USA) (Track 1).bin:

    • CRC32: BDDB8612
    • SHA1: 3bcaeabf76ae76435091325275d831f50af08521
    • MD5: 1f342e85e6fbafa98e3ddc4619c02807
    • Serial: 4419 (NOTE: the redump dat wrongly lists this one as 4423)
  • Double Switch (USA):

    • CRC32: C9011B75
    • SHA1: 54898d3fcebcffede1896f51ebea2ac8f34b96ce
    • MD5: 6e2c0e2519cca290c7aa860ee56fd8c0
    • Serial: 4419 (Note: the redump dat has this one correct)

So here's what's happening:

  • The two titles actually have identical serials.
  • Sega-CD detection function correctly reads the Silpheed (USA) (Track 1).bin serial as 4419.
  • The dB check for duplicates doesn't return any, because these two titles wrongly do not have the same serial listed in the dB.
  • So the detection concludes that Silpheed (USA) (Track 1).bin must be Double Switch (USA).

Contributor guide

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First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Inspect metadat/redump/Sega - Mega-CD - Sega CD.dat around line 2890 and compare the Silpheed and Double Switch serial entries with the checksums and serials reported here. Confirm that the metadata represents Silpheed with serial 4419 while preserving the correct Double Switch entry, then verify that content detection no longer identifies Silpheed as Double Switch.

Written by the indexing model from the issue text.

Assessment

Domain
databases
Issue type
Bug
Difficulty
2/5
Estimated time
1-3 hours
Activity status
Stale
Clarity
Clearly specified
Newbie friendliness
42/100

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