addf8.d (47 kB)File Description: SPPACK file
File Extension: Commonly .d
File Byte Order: Big-endian or little-endian
Prof. Peter Kabal, MMSP Lab, ECE, McGill University: Last update: 2017-01-20
SPPACK files were in use at AT&T Bell Laboratories. In addition to sampled data, they can store frequency domain and quefrency domain data. Peter Kroon (now with Intel Mobile Communications) maintained a signal processing library and promoted the use of this format.
The file header is 512 bytes long. SPPACK files contain single channel or stereo data. Normally, the data is in big-endian byte order, but there is some indication that little-endian SPPACK files have also been used.
| Offset | ength | Type | Contents |
|---|---|---|---|
| 0 | 80 | character | Comment string |
| 80 | 80 | character | Comment string |
| 160 | 80 | character | Command line |
| 240 | 2 | integer | Domain: 1 - Time;
2 - Frequency;
3 - Quefrency |
| 242 | 2 | integer | Frame size |
| 244 | 4 | float | Sampling frequency |
| 248 | 4 | character | - |
| 252 | 2 | character | File magic: 0x40C3 |
| 254 | 2 | integer | Data type: 0xFCOE
for sampled data |
| 256 | 2 | integer | Resolution: 8 or 16 |
| 258 | 2 | integer | Companding: 1 - 16-bit integer;
2 - µ-law;
3 - A-law |
| 260 | 80 | character | Text string |
| 340 | 80 | character | Text string |
| 420 | 80 | character | Text string |
| 500 | 2 | integer | DAT-Link information: Magic: 4567 |
| 502 | 2 | integer | Left-channel flag |
| 504 | 2 | integer | Right-channel flag |
| 506 | 6 | character | - |
| 512 | - | samples | Audio data |
addf8.d (47 kB)