Monday, July 19, 2010

I'll be gone for a while...

I'm going to a scouts camp in Denmark for 10 days, so i won't be able to work on my projects... :(
I'll be back the 29'th!

Friday, July 2, 2010

Progress on PPM.py + a preview on a Flipnote player

I have learned a bit about how the sound works in the PPM file.
I have documented what i found out in the sound header here: http://www.dsibrew.org/wiki/Flipnote_Files/PPM#Sound_data_section
I have also been able to extract all the sounds, but their all very static sounding.

I'll give you a little taste of how far i've come:

Original Flipnote:
http://flipnote.hatena.com/930EDBE0CC6FF483@DSi/movie/6FF483_0948E7A5F44D5_000
Extracted sound, only multiplied every byte by 16(RAW-ish):
http://www.mediafire.com/?dgxd20yqmjd
Extracted sound, how far i've come so far(See below for details)
http://www.mediafire.com/?omuyjwyxbog

I have found out that if you multiply each byte by 16, and play it as a 32000Hz PCM data, you get about the correct speed.

And here is my decoder in Python:
Output = []
for i in Input:
    i1 = ord(i)&0xF
    i2 = (ord(i)>>4)&0xF
    if  (i1&0x8): i1 = 0xF-(i1&0x7)
    if  (i2&0x8): i2 = 0xF-(i2&0x7)
    Output.append(chr(i1 * 0x10 + i2 )*16)
Output = "".join(Output)


And here is the preview of the Flipnote player I'm also making:


Update: Project discontinued(PPM.py,and PPMplayer)