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Virtual CUE/BIN/ISO/WAV Exports

The library can present a CHD image as a virtual CUE sheet with BIN/ISO/WAV files — no conversion to disk required. Mount the image with a GenericCue* console type and the resulting .cue, .bin/.iso, and per-track .wav files appear as entries in the virtual file tree, readable through the normal ReadFile API.

Export modes

ConsoleType Output Data sector size Audio
GenericCueBin2352 .cue + .bin 2352 (raw) inside .bin
GenericCueBin2048 .cue + .bin 2048 (cooked) inside .bin (still 2352-byte sectors)
GenericCueIso2352 .cue + .iso 2352 inside .iso
GenericCueIso2048 .cue + .iso 2048 inside .iso
GenericCueBinWav2352 .cue + .bin + .wav per audio track 2352 separate .wav files
GenericCueBinWav2048 .cue + .bin + .wav per audio track 2048 separate .wav files
GenericCueIsoWav2352 .cue + .iso + .wav per audio track 2352 separate .wav files
GenericCueIsoWav2048 .cue + .iso + .wav per audio track 2048 separate .wav files

Special case: MountAndParse(ConsoleType.PcEngineCd) and ConsoleType.PcFx additionally build a virtual CUE/BIN export (2352 mode) alongside the parsed track files, so the raw disc can still be re-assembled.

Generated files

Mounting, for example, game.chd with GenericCueBinWav2352 produces:

Virtual file Contents
\game.cue CUE sheet with FILE/TRACK/INDEX statements for every track
\game.bin Data tracks (raw 2352-byte sectors)
\game_TrackNN.wav One WAV per audio track — game_Track01.wav, game_Track02.wav, ... (two-digit, zero-padded). 44-byte PCM header, 16-bit 44.1 kHz stereo

Names derive from the CHD file name (e.g. game.chd → game.cue).

Sector-size rules (important)

  • Data tracks use the mode's sector size: 2048 bytes for the *2048 variants, otherwise min(UnitBytes, 2352).
  • Audio tracks inside BINARY files always use 2352-byte sectors, even in the 2048-cooked variants — this keeps audio track boundaries exact on real CD hardware. (Only GenericCueBin2048-style cooked exports where the raw unit is below 2352 deviate.)
  • WAV exports contain exactly the audio frames of the track: the stored pregap silence is skipped and the file starts at INDEX 01 00:00:00. Each WAV has a standard 44-byte RIFF/PCM header.

CUE track modes

The CUE sheet writes MODE1/2352, MODE2/2352, MODE1/2048, MODE2/2048, etc. according to the actual sector size used for that track and the track type from the CHD metadata (MODE1/MODE2/CDI detection). Audio tracks are written as AUDIO.

Why use virtual exports?

  1. No conversion — a CHD stays a CHD on disk; the CUE/BIN/ISO/WAV materializes only when you read it.
  2. Emulator compatibility — many emulators accept CUE/BIN or CUE/ISO but not CHD. Mount + read the virtual files into a RAM disk or extract them to disk.
  3. Selective extraction — extract only the .cue + data file, or only a specific WAV track, without reading the whole image.
  4. PC Engine CD / PC-FX — get a standard CUE/BIN of the disc even though no file system exists.

Example: extract a CUE/BIN set to disk

using VideoGameFileSystemParser.Models;
using VideoGameFileSystemParser.Parsers;

using var container = new ChdContainer(@"C:\ROMs\game.chd");
if (!container.MountAndParse(ConsoleType.GenericCueBin2352))
{
    Console.WriteLine("Mount failed.");
    return;
}

foreach (var entry in container.Entries)
{
    if (entry.IsDirectory) continue;

    var outPath = Path.Combine(@"C:\out", entry.Name);
    using var fs = File.Create(outPath);
    var buffer = new byte[256 * 1024];
    ulong offset = 0;
    while (offset < entry.Size)
    {
        int read = container.ReadFile(entry, offset, buffer, 0, buffer.Length);
        if (read <= 0) break;
        fs.Write(buffer, 0, read);
        offset += (ulong)read;
    }
    Console.WriteLine($"Extracted {entry.Name} ({entry.Size:N0} bytes)");
}

Example: inspect the generated CUE sheet

container.MountAndParse(ConsoleType.GenericCueBinWav2352);

var cueFile = container.FindFile("\\game.cue");
if (cueFile is not null)
{
    var cueData = new byte[cueFile.Size];
    container.ReadFile(cueFile, 0, cueData, 0, cueData.Length);
    Console.WriteLine(Encoding.ASCII.GetString(cueData));
}

Behavior notes

  • MountAndParse with a GenericCue* type never touches a file system parser — the tree consists purely of the virtual export files.
  • Reading the .cue/.bin/.iso/.wav entries uses the same ReadFile API as real files; the bytes are generated on demand.
  • The virtual files honor TrackInfo layout: track order, pregaps/postgaps, and per-track sector modes come straight from the CHD's track metadata.
  • Extraction is byte-exact: a .bin extracted from a virtual export can be used with its .cue in any standards-compliant emulator or burning tool.

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