CHD (Gotcha Force)

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This article is about Gotcha Force CHD file format and ongoing researchs on it. See CHD (File format) for CHD file format description.

This section needs a lot of research.

Research on how the header works and how the file interacts is needed.

GCD of CHD lengths = 16

CHD files contains several blocks:

0x0 "Head" Header CHD

• 0x4 - 4 bytes uint - Prog block header offset.
• 0x8 - 4 bytes - Quantity?
• 0xC - 4 bytes uint - Total file length.
• 0x10 - 4 bytes - Unknown
• 0x14 - 4 bytes - Unknown
• 0x18 - 4 bytes uint - Smpl block header offset.
• 0x1C - 4 bytes uint - DSPi block header offset.

0x20 "Prog" It could describe audio datas or script.

• 0x24 - 4 bytes uint - data block length.
• 0x28 - 4 bytes - Quantity?
• 0x2C - 4 bytes - -1 ?

0x0 "Smpl" Samples ?

• 0x4 - 4 bytes uint - data block length.
• 0x8 - 4 bytes - Samples count? (In hexadecimal - Ex 0x68 = 104 + 1(0,1,2....104))
• 0xC - 4 bytes - -1 ?

0x0 "Dspi" DSP for DSPADPCM, idea for further investigations: List of DSP in DPK (Gotcha Force).

• 0x4 - 4 bytes uint - data block length.
• 0x8 - 4 bytes - DSP count? (In hexadecimal)
• 0xC - 4 bytes - -1 ?