> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/dolphin-emu/dolphin/llms.txt
> Use this file to discover all available pages before exploring further.

# convert - Format Conversion

> Convert GameCube and Wii disc images between different formats

The `convert` command converts disc images between ISO, GCZ, WIA, and RVZ formats with various compression options.

## Usage

```bash theme={null}
dolphin-tool convert [options]
```

## Options

<ParamField path="-i FILE, --input=FILE" type="string" required>
  Path to the source disc image file.

  ```bash theme={null}
  dolphin-tool convert -i game.iso
  ```

  Supported input formats:

  * ISO/GCM (uncompressed)
  * GCZ (Dolphin compressed)
  * WIA (Wii Image Archive)
  * RVZ (Revolutionary)
  * WBFS (Wii Backup File System)
</ParamField>

<ParamField path="-o FILE, --output=FILE" type="string" required>
  Path to the destination file.

  ```bash theme={null}
  dolphin-tool convert -i game.iso -o game.rvz
  ```

  The output extension should match the format specified with `-f`.
</ParamField>

<ParamField path="-f FORMAT, --format=FORMAT" type="string" default="rvz">
  Container format to use for the output file.

  ```bash theme={null}
  dolphin-tool convert -i game.iso -o game.rvz -f rvz
  ```

  Available formats:

  * `iso` - Uncompressed disc image
  * `gcz` - GameCube compressed format
  * `wia` - Wii Image Archive
  * `rvz` - Revolutionary (recommended)

  Default is `rvz` if not specified.
</ParamField>

<ParamField path="-b BLOCK_SIZE, --block_size=BLOCK_SIZE" type="integer">
  Block size for GCZ/WIA/RVZ formats, in bytes.

  ```bash theme={null}
  dolphin-tool convert -i game.iso -o game.rvz -f rvz -b 131072
  ```

  **Required** for GCZ, WIA, and RVZ formats.

  Recommended values:

  * **RVZ**: `131072` (128 KiB) - Best balance
  * **WIA**: `131072` (128 KiB)
  * **GCZ**: `16384` (16 KiB) - Legacy compatibility

  Valid range: Usually 32768 to 2097152 bytes
</ParamField>

<ParamField path="-c COMPRESSION, --compression=COMPRESSION" type="string">
  Compression method for WIA/RVZ formats.

  ```bash theme={null}
  dolphin-tool convert -i game.iso -o game.rvz -f rvz -c zstd
  ```

  **Required** for WIA and RVZ formats.

  Available methods:

  * `none` - No compression
  * `zstd` - Zstandard (RVZ only, **recommended**)
  * `bzip2` - Bzip2 compression
  * `lzma` - LZMA compression
  * `lzma2` - LZMA2 compression

  **Note**: WIA does not support `zstd`. RVZ does not support `purge`.
</ParamField>

<ParamField path="-l LEVEL, --compression_level=LEVEL" type="integer">
  Compression level for the selected method.

  ```bash theme={null}
  dolphin-tool convert -i game.iso -o game.rvz -f rvz -c zstd -l 5
  ```

  **Required** when compression is not `none`.

  Recommended values for Zstandard:

  * `5` - Good balance (recommended)
  * `1-9` - Fast compression
  * `10-19` - Better compression
  * `20-22` - Maximum compression (slow)

  Valid range depends on compression method:

  * **Zstandard**: 1-22
  * **Bzip2**: 1-9
  * **LZMA/LZMA2**: 0-9
</ParamField>

<ParamField path="-s, --scrub" type="flag">
  Remove junk data during conversion to reduce file size.

  ```bash theme={null}
  dolphin-tool convert -i game.iso -o game.rvz -f rvz -s
  ```

  Scrubbing:

  * Removes unused data from disc image
  * Reduces file size
  * May not work with all games
  * **Warning**: RVZ already has excellent compression; scrubbing provides minimal benefit

  Only supported for GameCube and Wii disc images. Cannot scrub Datel discs.
</ParamField>

<ParamField path="-u USER, --user=USER" type="string">
  User folder path for temporary processing files.

  ```bash theme={null}
  dolphin-tool convert -i game.iso -o game.rvz -u /tmp/dolphin
  ```

  Will be automatically created if not set. Used for temporary data during conversion.
</ParamField>

## Examples

### Convert ISO to RVZ (Recommended)

Best balance of size and speed:

```bash theme={null}
dolphin-tool convert \
  -i game.iso \
  -o game.rvz \
  -f rvz \
  -b 131072 \
  -c zstd \
  -l 5
```

### Maximum Compression

For archival purposes:

```bash theme={null}
dolphin-tool convert \
  -i game.iso \
  -o game.rvz \
  -f rvz \
  -b 131072 \
  -c zstd \
  -l 22
```

### Fast Conversion

Quicker processing with moderate compression:

```bash theme={null}
dolphin-tool convert \
  -i game.iso \
  -o game.rvz \
  -f rvz \
  -b 131072 \
  -c zstd \
  -l 1
```

### Convert to ISO (Decompress)

Extract to plain ISO format:

```bash theme={null}
dolphin-tool convert \
  -i game.rvz \
  -o game.iso \
  -f iso
```

Note: `-b`, `-c`, and `-l` are not needed for ISO output.

### Convert with Scrubbing

Remove junk data while converting:

```bash theme={null}
dolphin-tool convert \
  -i game.iso \
  -o game.rvz \
  -f rvz \
  -b 131072 \
  -c zstd \
  -l 5 \
  -s
```

### Legacy GCZ Format

For older Dolphin versions:

```bash theme={null}
dolphin-tool convert \
  -i game.iso \
  -o game.gcz \
  -f gcz \
  -b 16384
```

### WIA Format

Using LZMA2 compression:

```bash theme={null}
dolphin-tool convert \
  -i game.iso \
  -o game.wia \
  -f wia \
  -b 131072 \
  -c lzma2 \
  -l 5
```

## Compression Comparison

Typical compression ratios for a 4.3 GB Wii game:

| Format | Compression | Level | Size   | Time   |
| ------ | ----------- | ----- | ------ | ------ |
| ISO    | None        | -     | 4.3 GB | -      |
| GCZ    | Deflate     | -     | 2.1 GB | 5 min  |
| RVZ    | Zstandard   | 5     | 1.8 GB | 3 min  |
| RVZ    | Zstandard   | 22    | 1.6 GB | 15 min |
| RVZ    | LZMA2       | 5     | 1.7 GB | 12 min |

*Times are approximate on modern hardware*

## Format Recommendations

### For General Use: RVZ with Zstandard

```bash theme={null}
-f rvz -b 131072 -c zstd -l 5
```

**Pros**:

* Excellent compression ratio
* Fast compression/decompression
* Modern codec
* Best overall choice

### For Maximum Compatibility: ISO

```bash theme={null}
-f iso
```

**Pros**:

* Works everywhere
* No decompression overhead
* Easy to mount/modify

**Cons**:

* Very large file size
* Requires external compression for storage

### For Legacy Systems: GCZ

```bash theme={null}
-f gcz -b 16384
```

**Pros**:

* Compatible with older Dolphin versions
* Decent compression

**Cons**:

* Superseded by RVZ
* Larger than RVZ
* Not recommended for new conversions

## Warnings and Messages

DolphinTool may display warnings during conversion:

### Scrubbing RVZ Warning

```
Warning: Scrubbing an RVZ container does not offer significant space advantages.
```

RVZ compression is already very efficient. Scrubbing provides minimal additional benefit.

### Scrubbing ISO Warning

```
Warning: Scrubbing does not save space when converting to ISO unless using external compression.
```

Scrubbed ISOs are still uncompressed. Use RVZ for better results.

### Wii to GCZ Warning

```
Warning: Converting Wii disc images to GCZ without scrubbing may not offer space advantages over ISO.
```

GCZ works best with GameCube games. Use RVZ for Wii games.

### NKit Warning

```
Warning: Converting an NKit file, output will still be NKit!
```

NKit images remain in NKit format after conversion. This may affect compatibility.

### Block Size Compatibility

```
Warning: For GCZs to be compatible with Dolphin < 5.0-11893, the file size must be an integer multiple of the block size...
```

Older Dolphin versions have stricter GCZ requirements.

## Error Messages

### No input set

Missing `-i` option. Specify input file:

```bash theme={null}
-i game.iso
```

### No output set

Missing `-o` option. Specify output file:

```bash theme={null}
-o game.rvz
```

### No output format set

Missing or invalid `-f` option. Choose from: `iso`, `gcz`, `wia`, `rvz`

### Block size must be set for GCZ/RVZ/WIA

Compressed formats require `-b` option:

```bash theme={null}
-b 131072
```

### Compression method must be set for WIA or RVZ

WIA and RVZ require `-c` option:

```bash theme={null}
-c zstd
```

### Compression level must be set when compression type is not 'none'

Specify `-l` when using compression:

```bash theme={null}
-l 5
```

### The input file could not be opened

Check:

* File exists
* File path is correct
* You have read permissions
* File is not corrupted

### Conversion failed

General failure. Check:

* Sufficient disk space
* Valid input file
* Write permissions for output directory

## Performance Tips

1. **Use SSD storage** - Significantly faster than HDD
2. **Higher compression levels** - Slower but smaller files
3. **Larger block sizes** - Better compression ratio, slightly slower
4. **Zstandard compression** - Best speed/ratio balance

## Batch Conversion Script

Convert all ISOs in a directory:

```bash theme={null}
#!/bin/bash

INPUT_DIR="./games"
OUTPUT_DIR="./converted"

mkdir -p "$OUTPUT_DIR"

for iso in "$INPUT_DIR"/*.iso; do
  filename=$(basename "$iso" .iso)
  echo "Converting $filename..."
  
  dolphin-tool convert \
    -i "$iso" \
    -o "$OUTPUT_DIR/$filename.rvz" \
    -f rvz \
    -b 131072 \
    -c zstd \
    -l 5
  
  if [ $? -eq 0 ]; then
    echo "✓ Converted $filename"
  else
    echo "✗ Failed: $filename"
  fi
done
```

## See Also

* [Verify Command](/cli/dolphin-tool/verify) - Verify converted images
* [Header Command](/cli/dolphin-tool/header) - Inspect compression settings
* [DolphinTool Overview](/cli/dolphin-tool/overview) - Other utilities