Flipnote Files/PPM: Difference between revisions

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PCM to ADPCM
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The sound data seems to be a variant of VOX ADPCM @ around 8KHz.
The sound data is 4bit ADPCM with reversed nibbles @ 8kHz.


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You can decode the sound yourself with "sox -t ima -N [input] [output]"
 
I have yet to figure out how to get rid of the noice when decoding sound...--[[User:Pbsds|pbsds]] 17:38, 6 June 2010 (UTC)


==Signature==
==Signature==


The last 0x10-bytes in a PPM are all-zero. The 0x80 bytes before that is a RSA-1024 SHA-1 signature over the whole PPM, excluding the last 0x90 bytes with the signature.
The last 0x10-bytes in a PPM are all-zero. The 0x80 bytes before that is a RSA-1024 SHA-1 signature over the whole PPM, excluding the last 0x90 bytes with the signature.