Many of the registers in OV2640_JPEG_INIT[][2] are not mentioned in the manual of OV2640.

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For example:
SCCB write failure: 0xe5 0x3f
SCCB write failure: 0xc9 0x9d
SCCB write failure: 0x91 0x07
SCCB write failure: 0x93 0x68
SCCB write failure: 0x97 0x13