DSiBrew

Flipnote Files/PPM: Difference between revisions

← Older edit
Pbsds (talk | contribs)
104 edits
Pbsds (talk | contribs)
104 edits
 
(11 intermediate revisions by 5 users not shown)
Line 2: Line 2:


/private/ds/app/4B475556/001 - European location
/private/ds/app/4B475556/001 - European location
/private/ds/app/4B475545/001 - North American location


You can save your images in a user folder as long as it's on the same level as the 001 folder.  Clicking on the Choose Folder icon on the top of the View Flipnote / SD Card option gives you a list of normal folders, and you can swap to user folders by selecting the normal button again.  This could possibly be to overcome a limitation in one of the files (possibly the dirmemo2.lst file).
You can save your images in a user folder as long as it's on the same level as the 001 folder.  Clicking on the Choose Folder icon on the top of the View Flipnote / SD Card option gives you a list of normal folders, and you can swap to user folders by selecting the normal button again.  This could possibly be to overcome a limitation in one of the files (possibly the dirmemo2.lst file).
Line 206: Line 207:
|-
|-
| 0000
| 0000
| 4
| 2
| Size of the offset table
| Size of the offset table
|-
| 0002
| 2
| Padding
|-
|-
| 0004
| 0004
Line 310: Line 315:


if( useByte == 0 ) // Set the full line to the current paper colour
if( useByte == 0 ) // Set the full line to the current paper colour
        {
memset( outB, paper, 256 );
memset( outB, paper, 256 );
        }
else // Bytes in this line, read and deal with them
else // Bytes in this line, read and deal with them
{
{
Line 323: Line 330:
{
{
if( ( data & 0x01 ) == 0x01 )
if( ( data & 0x01 ) == 0x01 )
                                        {
outB[ x ] = invflag == 0 ? pen : paper;
outB[ x ] = invflag == 0 ? pen : paper;
                                        }
else
else
                                        {
outB[ x ] = invflag == 0 ? paper : pen;
outB[ x ] = invflag == 0 ? paper : pen;
 
                                        }
x ++;
x ++;


Line 342: Line 352:


if( x < 256 )
if( x < 256 )
                {
memset( &outB[ x ], paper, 256 - x );
memset( &outB[ x ], paper, 256 - x );
                }
}
}


Line 358: Line 370:
|- style="background-color: #ddd;"
|- style="background-color: #ddd;"
! Length
! Length
! Function
! Description
! Description
|-
|-
| Frame count
| Framecount
| Sound effect usage. Each byte represents a frame, and bit #1 represents Sound effect 1, bit #2 represents Sound effect 2 and bit #3 represents Sound effect 3.
| Sound effect usage.
| Each byte represents a frame. bit #1(from Right to Left) represents Sound effect 1, bit #2 represents Sound effect 2 and bit #3 represents Sound effect 3. the last 5 bits is padding.
|-
|-
| 0 - 3
| 0 - 3
| Padding - Makes the offset to the next four bytes dividable by 4
| Padding
| 0x00 * (0 to 3). Makes the offset to the next value dividable by 4.
|-
|-
| 4
| 4
| Size of Background music(0x0000000 if not used)
| Size of the background music.
| The size of the background music in bytes in the audio data below. 0x0 if not used/empty.
|-
|-
| 4
| 4
| Size of Sound effect 1(0x0000000 if not used)
| Size of sound effect #1
| The size of the sound effect #1 in bytes in the audio data below, max size is 0x2000. 0x0 if not used/empty.
|-
|-
| 4
| 4
| Size of Sound effect 2(0x0000000 if not used)
| Size of sound effect #2
| The size of the sound effect #3 in bytes in the audio data below, max size is 0x2000. 0x0 if not used/empty.
|-
|-
| 4
| 4
| Size of Sound effect 3(0x000000 if not used)
| Size of sound effect #3
| The size of the sound effect #3 in bytes in the audio data below, max size is 0x2000. 0x0 if not used/empty.
|-
| 1
| Current Framespeed.
| This is the speed of the flipnote. It's in the range of 1-8. To get the correct value, you must take 8, and subtract the decimal value of this byte.
|-
|-
| 1
| 1
| Framerate. To get the correct value, you must take 8, and subtract the decimal value of this byte.
| Given Framespeed when BGM was recorded.
| This is the speed of the flipnote when the BGM was recorded/modified. It's in the range of 1-8. This is used to resample the sound to the new speed. To get the correct value, you must take 8, and subtract the decimal value of this byte.
|-
|-
| 15
| 14
| Unknown - Used for sound decoding? (samplerate, compression, etc)
| Padding
| 0x00 * 14
|}
|}


I have yet to figure out the sound decoding...--[[User:Pbsds|pbsds]] 17:38, 6 June 2010 (UTC)
Then comes the audio data.
 
*First comes the BGM(if used)
 
*Then comes sound effect #1(if used)
 
*Then comes sound effect #2(if used)
 
*Then comes sound effect #3(if used)
 
 
The sound data is 4bit ADPCM with reversed nibbles @ 8kHz.
 
You can decode the sound yourself with "sox -t ima -N [input] [output]"
 
==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.
Retrieved from "https://dsibrew.org/wiki/Flipnote_Files/PPM"