What's New in 3.5.1

Released: 2026-09-02

Changed

chdman is now the primary encoder. Conversions run on the bundled chdman, the reference MAME CHD encoder. If chdman fails on a file, the conversion automatically falls back to CHDSharp.exe — the managed encoder whose output is byte-identical to chdman. The fallback reuses the already-prepared cue work directory and ASCII staging, so a cue's work set stays valid and nothing is re-prepared.
A batch is no longer blocked when only one encoder is present. If chdman.exe is missing but CHDSharp.exe is available, every file is converted with CHDSharp; if CHDSharp is missing, chdman carries the batch alone. The startup notice now shows a critical error only when both encoders are missing.
Duplicate output targets are skipped, not overwritten. When two inputs in the same batch would produce the same .chd (for example Game.7z and Game.iso sitting side by side), the redundant input is skipped up front and the resolution is logged — the first non-archive input wins, and the redundant archive is no longer extracted and converted just to be overwritten.

PSP .pbp extraction now uses the reference-compatible SharpZipLib inflater for PSAR block decompression, so images that the stricter .NET DeflateStream rejected with InvalidDataException extract correctly. The bundled CHDSharp was updated as part of this fix.
A bare .bin with no cue and no readable sector header (for example a console BIOS dropped into the input folder) is again treated as informational only — it logs guidance instead of triggering a bug report.
Live write-speed (MB/s) stat card now updates during CHDSharp-driven conversions (it previously froze at 0.0 MB/s), and the elapsed-time card ticks every second during long single-file conversions.
chdman Input/output error messages now include actionable guidance (failing or disconnected drive, antivirus/cloud-sync file locks, damaged image).

Bug reports are de-duplicated: an identical warning repeated inside a 10-minute window (a failing batch retrying the same input, a loop logging the same warning per file) is sent once.
Alcohol 120% (.mds/.mdf) and UltraISO (.isz) support moved into standalone. No functional change.

Analyzers upgraded: Meziantou.Analyzer 3.0.200, Roslynator.Analyzers 5.0.0 added, with analyzer fixes applied across the solution.
Removed the internal CHDBattleTest battleground project (its parity results live on in the CHDSharp documentation); updated the bundled 7-Zip binaries.
Test suite grown to 813 passing tests, including new coverage for duplicate-output resolution and ISZ header sizing.

Full Changelog: release_3.5.0...release_3.5.1