Folder Scanning does not detect games in CHD format

I’m curious if it’s me and something I’ve done, or if the Import Content feature simply doesn’t know how to parse CHD files.

If I have a CHD “Crash Bandicoot” for PSX and run the import content feature, the file appears to be scanned, shows the scanning indicator on the lower left of the screen, and stops with no update to the (playlist) file.

If I extract the BIN/CUE from the CHD, then run import content, the scanning indicator displays, and Crash Bandicoot is added to the file.


Correct, CHDs don’t scan, unfortunately.

CHDs do scan, and have for some time.

In fact I just did a test with Sega CD and Playstation and it works fine.

[INFO] Comparing with known magic numbers...
[INFO] CHD 'D:\RetroArch\roms\Console\Disc\Sonic CD (USA).chd' crc: a6184e05
[INFO] Written to playlist file: D:\RetroArch\playlists\Sega - Mega-CD - Sega
[INFO] Comparing with known magic numbers...
[INFO] Found disk label 'SLUS-00493'
[INFO] Written to playlist file: D:\RetroArch\playlists\Sony -
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oops, my mistake! :slight_smile:

I dug into this more deeply and recognize where a prerequisite for proper recognition is installing a CHD-Compatible core. I can also understand if some of the images have unique identifiers that aren’t in the database.

In testing, I am getting different results between Windows, Lakka, and Android for the exact same content & cores. For 12 SegaCD discs where both PicoDrive (not CHD-compatible) & GenesisPlusGX (CHD-Compatible) cores were installed. With the exception of Lakka whose cores are installed in the OS image (you can’t update them online/within Lakka), Windows and Android’s cores were updated just prior to testing:

  Android - Retroarch 1.8.1                -  0 added to playlist
  Lakka   - Retroarch 2019-11-04/odroidXU3 - 12 added to playlist
  Windows - Retroarch 1.8.1                -  8 added to playlist

Android reports in the log “Comparing with known magic numbers…”, “Could not find compatible system”, no matches

Lakka reports in the log “Comparing with known magic numbers…” then matches 12 of 12.

Windows reports in the log “Comparing with known magic numbers…” then matches 8 of 12.

I converted all my PS1 ISOs to CHD. They play fine. But when I attempt to scan them to update my PS1 playlist, it always crashes Retroarch. 1.9.0, Playstation Classic. Any fix?

Manual Scan worked. Told it the playlist, to scan inside archives, and the chd file extension. No crash after doing so.

On some systems, manual scanning will work with chd and some will not.
These lists are based on Redump DATs or similar, and the image names are cue+bin, little by little the chd are included in the retroArch lists and updated, it is a matter of testing.

Oh neat. Nobody’s ever replied to me before. But won’t the checksums to compare with vary by compression level? I want to believe the CHD tool I used used the best compression, but I’ve seen CSO and EBOOT tools have as many as 9 levels to choose from. I suppose the original checksums are the only reliable indicator, making extraction necessary, however intense. To that I shudder after seeing take hours to extract on Vita’s RetroArch.

Side note: I have to keep an uncompressed copy of Mega Man X5 Improvement Project for hex editing. Because someone thought it was a great idea to remove the D-pad double-tap dash feature that’s been around since the 90s without any in-game configuration.

The chd is a compressed file, similar to a zip, the cue+bin content is intact inside. RetroArch reads what is inside, no matter what compressor you use, although, I recommend the native MAME compressor tool, it is an original format from them.