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The header command displays information about disc image files, including game metadata, compression settings, and format-specific details.

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Usage

dolphin-tool header [options]

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Options

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-i FILE, --input=FILE
string
required
Path to the disc image file to inspect.
dolphin-tool header -i game.iso
Supported formats:
  • ISO/GCM
  • GCZ
  • WIA
  • RVZ
  • WBFS
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-j, --json
flag
Output information as JSON format, then exit.
dolphin-tool header -i game.iso --json
Overrides other print options (-b, -c, -l).
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-b, --block_size
flag
Print only the block size of GCZ/WIA/RVZ formats, then exit.
dolphin-tool header -i game.rvz --block_size
Output: 131072 (or N/A for formats without block size)
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-c, --compression
flag
Print only the compression method of GCZ/WIA/RVZ formats, then exit.
dolphin-tool header -i game.rvz --compression
Output: Zstandard (or N/A for uncompressed formats)
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-l, --compression_level
flag
Print only the compression level for WIA/RVZ formats, then exit.
dolphin-tool header -i game.rvz --compression_level
Output: 5 (or N/A for formats without compression levels)

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Output Formats

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Default Human-Readable Output

Without flags, displays all available information: 
dolphin-tool header -i game.rvz
Example output: 
Block Size: 131072
Compression Method: Zstandard
Compression Level: 5
Internal Name: Super Smash Bros. Melee
Revision: 2
Game ID: GALE01
Title ID: 0000000000000000
Region: NTSC-U
Country: United States

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JSON Output

dolphin-tool header -i game.rvz --json
Example output: 
{
  "block_size": 131072,
  "compression_method": "Zstandard",
  "compression_level": 5,
  "internal_name": "Super Smash Bros. Melee",
  "revision": 2,
  "game_id": "GALE01",
  "title_id": 0,
  "region": "NTSC-U",
  "country": "United States"
}

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Single Value Output

For scripting, use specific flags: 
# Block size
dolphin-tool header -i game.rvz -b
# Output: 131072

# Compression method
dolphin-tool header -i game.rvz -c
# Output: Zstandard

# Compression level
dolphin-tool header -i game.rvz -l
# Output: 5

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Information Fields

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File Format Information

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Block Size

The block size used for compression (GCZ/WIA/RVZ only).
  • Measured in bytes
  • Common values: 16384, 32768, 65536, 131072, 262144
  • Larger blocks = better compression, slower random access

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Compression Method

The algorithm used for compression:
  • None - Uncompressed (ISO)
  • Deflate - GCZ compression
  • Bzip2 - Bzip2 compression (WIA/RVZ)
  • LZMA - LZMA compression (WIA/RVZ)
  • LZMA2 - LZMA2 compression (WIA/RVZ)
  • Zstandard - Zstandard compression (RVZ only)
  • Purge - Purge mode (WIA only)

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Compression Level

The compression level (WIA/RVZ only):
  • Range depends on compression method
  • Higher = better compression, slower
  • WIA/RVZ only; not applicable to GCZ

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Game Metadata

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Internal Name

The game’s internal title as stored on the disc: 
Internal Name: Super Smash Bros. Melee

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Game ID

The 6-character game identifier: 
Game ID: GALE01
Format: GALE01 where:
  • G - Platform (G=GameCube, R=Wii)
  • ALE - Game code
  • 01 - Region/version

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Title ID

The 64-bit title ID (Wii games only): 
Title ID: 0001000248414c45
GameCube games show 0.

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Revision

The disc revision number: 
Revision: 2
Higher numbers indicate later releases.

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Region

The disc region:
  • NTSC-U - North America
  • NTSC-J - Japan
  • NTSC-K - South Korea
  • PAL - Europe/Australia

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Country

Specific country/region:
  • United States
  • Japan
  • Europe
  • South Korea
  • etc.

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Examples

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Inspect ISO File

dolphin-tool header -i game.iso
Output: 
Internal Name: The Legend of Zelda Twilight Princess
Revision: 0
Game ID: RZDE01
Title ID: 0001000052524445
Region: NTSC-U
Country: United States
Note: No compression information for ISO files.

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Inspect RVZ File

dolphin-tool header -i game.rvz
Output: 
Block Size: 131072
Compression Method: Zstandard
Compression Level: 5
Internal Name: Mario Kart Wii
Revision: 1
Game ID: RMCE01
Title ID: 0001000052534245
Region: NTSC-U
Country: United States

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Get JSON Output

dolphin-tool header -i game.rvz --json
Useful for parsing with jq or other JSON tools: 
dolphin-tool header -i game.rvz --json | jq '.game_id'
# Output: "RMCE01"

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Check Block Size

dolphin-tool header -i game.rvz -b
Output: 
131072

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Check Compression Method

dolphin-tool header -i game.rvz -c
Output: 
Zstandard

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Check Compression Level

dolphin-tool header -i game.rvz -l
Output: 
5

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Scripting Examples

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List All Game IDs

#!/bin/bash

for file in *.{iso,rvz,gcz}; do
  [ -f "$file" ] || continue
  game_id=$(dolphin-tool header -i "$file" --json | jq -r '.game_id')
  echo "$file: $game_id"
done

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Check Compression Settings

#!/bin/bash

for rvz in *.rvz; do
  echo "File: $rvz"
  echo "  Block Size: $(dolphin-tool header -i "$rvz" -b)"
  echo "  Compression: $(dolphin-tool header -i "$rvz" -c)"
  echo "  Level: $(dolphin-tool header -i "$rvz" -l)"
done

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Identify Game by Title ID

#!/bin/bash

target_id="0001000052534245"  # Mario Kart Wii

for file in *.{iso,rvz}; do
  [ -f "$file" ] || continue
  title_id=$(dolphin-tool header -i "$file" --json | jq -r '.title_id')
  
  if [ "$title_id" = "$target_id" ]; then
    echo "Found: $file"
  fi
done

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Generate CSV Database

#!/bin/bash

echo "Filename,Game ID,Internal Name,Region" > games.csv

for file in *.iso; do
  json=$(dolphin-tool header -i "$file" --json)
  filename=$(basename "$file")
  game_id=$(echo "$json" | jq -r '.game_id')
  name=$(echo "$json" | jq -r '.internal_name')
  region=$(echo "$json" | jq -r '.region')
  
  echo "$filename,$game_id,$name,$region" >> games.csv
done

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Compare Compression Settings

#!/bin/bash

for file1 in *.rvz; do
  for file2 in *.rvz; do
    [ "$file1" = "$file2" ] && continue
    
    level1=$(dolphin-tool header -i "$file1" -l)
    level2=$(dolphin-tool header -i "$file2" -l)
    
    if [ "$level1" != "$level2" ]; then
      echo "$file1 (level $level1) vs $file2 (level $level2)"
    fi
  done
done

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Integration with jq

The JSON output works well with jq for advanced queries: 
# Extract specific field
dolphin-tool header -i game.rvz --json | jq '.internal_name'

# Filter by region
for file in *.iso; do
  region=$(dolphin-tool header -i "$file" --json | jq -r '.region')
  if [ "$region" = "NTSC-U" ]; then
    echo "$file is NTSC-U"
  fi
done

# Format custom output
dolphin-tool header -i game.rvz --json | \
  jq -r '"\(.game_id): \(.internal_name) [\(.region)]"'

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Use Cases

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Identify Unknown Images

Quickly identify what game an image contains: 
dolphin-tool header -i unknown.iso

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Verify Compression Settings

Check if images are compressed optimally: 
for rvz in *.rvz; do
  level=$(dolphin-tool header -i "$rvz" -l)
  if [ "$level" -lt 5 ]; then
    echo "$rvz: Low compression (level $level)"
  fi
done

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Organize Game Library

Sort games by region, ID, or name using metadata.

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Quality Control

Verify converted images have expected settings: 
block_size=$(dolphin-tool header -i game.rvz -b)
if [ "$block_size" != "131072" ]; then
  echo "Warning: Unexpected block size"
fi

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Error Messages

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”Error: No input set”

Missing -i option. Specify input file: 
dolphin-tool header -i game.iso

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“Error: Unable to open disc image”

Check:
  • File exists and path is correct
  • File is a valid disc image
  • You have read permissions

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Performance

Header inspection is very fast (< 1 second) as it only reads metadata, not the entire file.

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See Also