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After downloading DAT files, you need to process them to organize and prepare them for use with emulators and ROM managers. This guide covers the complete processing workflow.

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Understanding DAT Processing

Processing transforms raw DAT files into an organized structure by:
  • Loading and validating DAT file contents
  • Applying filters to select specific DATs
  • Executing actions (copy, deduplicate, merge)
  • Saving to your configured destination
  • Updating the internal database

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Basic Processing Workflow

1

Fetch DATs First

Ensure you have downloaded DATs before processing:
datoso redump --fetch
2

Process All DATs

Process all downloaded DATs from a seed:
datoso redump --process
This processes all DAT files from ~/.datoso/tmp/redump/dats/ and copies them to your configured destination.
3

Review Results

Datoso displays the status of each processed file:
==============================
Processing seed redump
------------------------------
Processed Sony - PlayStation.dat ['Created']
Processed Nintendo - GameCube.dat ['Updated']
Processed Sega - Dreamcast.dat ['Exists']
...
Finished processing redump

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Filtering DATs

Use filters to process only specific DAT files by name pattern: 
# Process only PlayStation DATs
datoso redump --process --filter PlayStation

# Process only Nintendo systems
datoso nointro --process --filter Nintendo

# Process only IBM PC DATs
datoso redump --process --filter "IBM"
The --filter parameter matches against the DAT filename, processing only files containing that string.

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Combined Fetch and Process

Fetch and process in one command: 
# Fetch then process all DATs
datoso redump --fetch --process

# Fetch then process with filter
datoso redump --fetch --process --filter Sony

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Processing Actions

Datoso executes a series of actions when processing each DAT. The default action pipeline includes:

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Standard Actions

  1. LoadDatFile - Loads and parses the DAT file
  2. DeleteOld - Removes outdated versions
  3. Copy - Copies to destination with proper organization
  4. SaveToDatabase - Updates internal database
  5. MarkMias - Marks missing-in-action ROMs (if enabled)

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Optional Actions

Additional actions can be enabled via configuration: 
# Enable automatic deduplication during processing
datoso config --set PROCESS.ParentMergeEnabled=True

# Enable auto-merge for DATs with automerge property
datoso config --set PROCESS.AutoMergeEnabled=True

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Processing Multiple Seeds

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Process All Seeds

Process DATs from all installed seeds: 
datoso all --process

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Selective Processing

# Process only specific seeds
datoso all --process --only redump fbneo

# Process all except certain seeds
datoso all --process --exclude nointro

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Advanced Processing Options

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Specify Custom Actions

Execute only specific actions during processing: 
# Only load and deduplicate, skip copying
datoso redump --process --actions LoadDatFile,Deduplicate

# Multiple actions
datoso redump --process --actions "LoadDatFile,Copy,SaveToDatabase"
Available actions:
  • LoadDatFile - Parse DAT file
  • DeleteOld - Remove old versions
  • Copy - Copy to destination
  • SaveToDatabase - Update database
  • MarkMias - Mark MIA ROMs
  • AutoMerge - Auto-merge duplicates
  • Deduplicate - Remove parent duplicates

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Verbose Output

See detailed processing information: 
# Enable verbose mode
datoso redump --process -v

# Quiet mode (minimal output)
datoso redump --process -q

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Processing Status Messages

Understanding the output:
StatusMeaning
CreatedNew DAT file created
UpdatedExisting DAT file updated with new version
ExistsDAT already exists and is current
OverwrittenDAT overwritten (when Overwrite=True)
DisabledDAT is disabled, not processed
DedupedDuplicates removed via parent merge
AutomergedInternal duplicates merged
No Action Taken, Newer FoundDatabase has newer version
ErrorProcessing error occurred

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Configuration Options

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Essential Processing Settings

# Set destination for processed DATs
datoso config --set PATHS.DatPath=/path/to/organized/dats

# Overwrite existing files even if same date
datoso config --set PROCESS.Overwrite=True

# Enable parent-based deduplication
datoso config --set PROCESS.ParentMergeEnabled=True

# Enable auto-merge for applicable DATs
datoso config --set PROCESS.AutoMergeEnabled=True

# Process Missing-in-Action ROMs
datoso config --set PROCESS.ProcessMissingInAction=True

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Ignore Patterns

Skip processing certain DATs with regex patterns: 
# Ignore DATs matching pattern
datoso config --set PROCESS.DatIgnoreRegEx="(Beta|Proto)"

# Ignore certain seeds
datoso config --set PROCESS.SeedIgnoreRegEx="deprecated"

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Output Directory Structure

Processed DATs are organized based on each seed’s rules: 
{DatPath}/
├── Redump/
│   ├── Sony - PlayStation/
│   │   └── Sony - PlayStation.dat
│   ├── Nintendo - GameCube/
│   │   └── Nintendo - GameCube.dat
│   └── ...
├── No-Intro/
│   ├── Nintendo - Game Boy/
│   │   └── Nintendo - Game Boy.dat
│   └── ...
└── ...
Each seed plugin defines its own folder structure rules. The structure above is simplified - actual organization may vary by seed.

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Troubleshooting

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Processing Fails

If processing encounters errors:
1

Enable verbose logging

datoso redump --process -v
2

Check log file

datoso log
3

Verify seed health

datoso doctor redump
4

Check file permissions

Ensure write permissions on the destination directory:
ls -ld ~/.datoso/DatRoot/

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Common Issues

“No Action Taken, Newer Found”
  • Your database already has a newer version
  • To force reprocess: datoso config --set PROCESS.Overwrite=True
“Disabled” Status
  • The DAT has been disabled in the database
  • Re-enable with: datoso dat -d seed:datname --set enabled=True
Filter Not Working
  • Ensure filter string matches part of the filename
  • Use quotes for filters with spaces: --filter "Sony - PlayStation"
Files Not Appearing
  • Check PATHS.DatPath configuration
  • Verify the seed’s action rules with verbose mode

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Example Workflows

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Complete Workflow for New Seed

# 1. Install seed
pip install datoso[redump]

# 2. Configure paths
datoso config --set PATHS.DatPath=/path/to/roms/dats

# 3. Fetch and process
datoso redump --fetch --process

# 4. Verify results
ls -R /path/to/roms/dats/

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Update Existing DATs

# Fetch updates
datoso redump --fetch

# Process only updated files
datoso redump --process

# Files with "Exists" status are already current

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Process Specific System

# Fetch all, process only PlayStation
datoso redump --fetch
datoso redump --process --filter PlayStation

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Next Steps

After processing, you may want to:
  1. Deduplicate DATs to remove redundant entries
  2. Manage DAT properties to enable/disable or configure specific DATs
  3. Work with seeds to install additional sources
Processing does not download ROMs - it only organizes DAT files that describe ROM collections. Use the processed DATs with ROM managers like ROMVault or CLRMamePro.

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