Op 1 Application Chunk format
The Application Specific chunk of an Op1 aiff contains:
| Chunk field | Type | Description |
|---|---|---|
| chunkId | ID | the string "APPL" |
| chunkSize | long | the size of the chunk in bytes, not including the chunkId or chunkSize |
| applicationSignature | OSType | the string "op-1" |
| data | char[] | a JSON string |
For drum kits, the JSON string in "data" contains the following fields:
| Field name | Notes |
|---|---|
| drum_version | contains the value 1 in all drum kits I have seen |
| type | contains the value "drum" for a drum kit |
| name | I saw the string "user" in a drum kit I created with the Drum Utility. I saw a snapshot timestamp ("20450912_0849") for a drum kit I saved to the snapshots folder by pressing and holding one of the preset buttons. |
| octave | Which octave the kit was configured with. Suspect the values are -4 to +4 |
| pitch | A 24 element array of integers. |
| start | A 24 element array of integers. Possibly the number of the sample frame that the sample starts at (yet to be researched). After some experimentation, I think the numbers range from 0 (far left) to 231 (far right). |
| end | A 24 element array of integers. Possibly the number of the sample frame that the sample ends at (yet to be researched). After some experimentation, I think the numbers range from 0 (far left) to 231 (far right). |
| playmode | A 24 element array of integers. 4096 is the value for the playmode "->". 8192 is the value for the playmode "->|". 20480 is the value for the loop playmode. |
| reverse | A 24 element array of integers. Seems to contain the value 8192 to represent normal playback. Have seen both 18432 and 19968 represent reverse playback, needs more investigation. |
| volume | A 24 element array of integers. |
| dyna_env | An 8 element array of integers. |
| fx_active | True or False |
| fx_type | "cwo", "delay", "grid" |
| fx_params | An 8 element array of integers. |
| lfo_active | True or False |
| lfo_type | "bend", "random", "tremelo", "value" |
| lfo_params | An 8 element array of integers. |