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https://github.com/ad1217/python-scom7330

A tool to manipulate various data, including Audio Libraries (ex CustomAudioLib.bin) for the SCOM 7330 repeater
https://github.com/ad1217/python-scom7330

ham-radio hamradio scom scom-7330

Last synced: 3 months ago
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A tool to manipulate various data, including Audio Libraries (ex CustomAudioLib.bin) for the SCOM 7330 repeater

Host: GitHub
URL: https://github.com/ad1217/python-scom7330
Owner: ad1217
License: mit
Created: 2021-01-05T15:59:58.000Z (almost 4 years ago)
Default Branch: main
Last Pushed: 2021-03-05T23:20:12.000Z (almost 4 years ago)
Last Synced: 2024-09-17T05:51:21.817Z (4 months ago)
Topics: ham-radio, hamradio, scom, scom-7330
Language: Python
Homepage:
Size: 114 KB
Stars: 0
Watchers: 3
Forks: 0
Open Issues: 0
Metadata Files:
- Readme: README.md
- License: LICENSE

Awesome Lists containing this project

README

        # SCOM 7330 Speech Library Tool

![Unit Tests](https://github.com/ad1217/SCOM7330_SpeechLib_Tool/workflows/Unit%20Tests/badge.svg)

This is a tool to manipulate Audio Libraries (such as

`CustomAudioLib.bin`) for the SCOM 7330 repeater, reverse engineered

from the provided `BuildSpeechLib.exe`.

The official tool, as well as default audio libraries, manuals,

firmware, etc. can be found at

http://www.scomcontrollers.com/7330firmware .

## Speech Library Format

**Remember that this is reverse engineered (so not guaranteed to be

accurate), and subject to change with firmware updates**

**This was derived from firmware release V1.8b,

  BuildSpeechLib.exe V1.2.0 (built 5/13/2018)**

The speech library file is composed of 4 sections:

- [Header](#header) (`0x100` bytes)

- [Image Header](#image-header) (`0x100` bytes)

- [Word Index](#word-index) (variable length, rounded up to the nearest `0x100`)

- [Word Data](#word-data) (variable length)

The header and image header contain metadata and the word index is a

lookup table into the data. Unused space is filled with `0xff` instead

of `0x00`, for unclear reasons.

In the following sections, byte ranges are presented as

`inclusive:exclusive`, like in Python. For example, `0x00:0x05`

includes the bytes `0x00`, `0x01`, `0x02`, `0x03`, and `0x04`. All

addresses in tables are relative to the start of the section, unless

stated otherwise.

### Header

- Address: `0x00`

- Length: `0x100`

| Byte  | 0x00:0x05  | 0x05:0x15 | 0x15:0x21 | 0x21:0x38 | 0x38 | 0x39:0x3c | 0x3c:0x3d | 0x3d:0x100 |

|:------|:-----------|:----------|:----------|:----------|:-----|:----------|:----------|:-----------|

| Value | `SCOM\x00` | name      | version   | timestamp | mode | firstFree | zeros     | (empty)    |

- `name`, `version`, and `timestamp` are just ASCII strings, and have

  no apparent function beyond display.

- `mode` is 3 in `BuildSpeechLib.exe`'s normal mode, 2 in the extended

  arguments form. I am not sure what this means, exactly.

- `firstFree` is the size of the file minus `0x100`, presumably to

  account for this header's size. Unclear what this is used for, as it

  also occurs (with the `0x100` included) in the [Image Header](#image-header)

- `zeros` is two two-byte arguments to the function in

  `BuildSpeechLib.exe` which were passed in as literal zeros. Unclear

  function.

### Image Header

- Address: `0x100`

- Length: `0x100`

| Byte  | 0x00:0x03      | 0x03           | 0x04:0x06    | 0x06:0x09 | 0x09:0x100 |

|:------|:---------------|:---------------|:-------------|:----------|:-----------|

| Value | `\x00\x02\x00` | index_size_mid | max_word + 1 | firstFree | (empty)    |

- I'm not sure what the purpose of the constant in `0x00:0x03` is

- `index_size_mid` is the middle byte of the [Word Index](#word-index)

  size. Since that size is rounded to `0x100`, this is just the index

  size shifted down 1 byte.

- `max_word + 1` is the highest word file contained, plus one.

  Not really sure why it's plus one.

- `firstFree` is the length of the file.

  Seems to be redundant with the value in the [Header](#header).

### Word Index

- Address: `0x200`

- Length: 4 times the maximum word code, rounded up to the nearest `0x100`

| Byte  | (word code * 4):(word code * 4) + 3 |

|:------|:------------------------------------|

| Value | word data address                   |

This section is a lookup table mapping the word code to the address of

the entry in the [Word Data](#word-data) section, relative to the file

start. All un-used entries are blank (`0xff`). Each entry is 4 bytes

long, but the address is stored just in the first 3 bytes (with the

last one being `0xff`.

### Word Data

- Address: `0x200` plus the the length of the [Word Index](#word-index),

  as stored in the [Image Header](#image-header).

- Length: 3 times the number of files, plus the length of each file

For each entry:

| Byte  | 0x00:0x03                | 0x03:end of file |

|:------|:-------------------------|:-----------------|

| Value | end of file data address | file data        |

- `end of file data address` is the address of the end of the audio file data.

- `file data` is the contents of a raw file (as per

  [Audio Files](#audio-files)), but with every byte greater than 127 xor'ed

  with 127 for some unclear reason.

## Audio Files

The input/output audio files are in the format specified in the SCOM manual:

- 8000 Hertz sampling rate

- Single channel (mono) audio

- μ-law encoding

- Raw headerless file

You can convert wav files (for example) to this format with `sox`:

```sh

sox --type wav .wav --type ul --rate 8k .raw

```

or from this format to wav:

```sh

sox --type ul --rate 8k --channels 1 .raw --type wav .wav

```

## Disclaimer

I am not affiliated with S-COM in any way. I make no guarantees of the

correctness of the code. Don't break your stuff.