Nintendo 3DS Sound

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Nintendo 3DS Sound is the music playing and audio recording application that is included with all retail consoles.

Voice Recorder[edit]

Like its predecessor for the DSi, up to 10-second recordings can be stored, with limited integration of those with other software.

Practically speaking, the single page of internal storage is for DSi-mode software, and the 10 pages of SD card storage are for 3DS software (like Flipnote Studio 3D).

File naming pattern[edit]

   sdmc:/Nintendo 3DS/private/00020500/voice/01/V13303.m4a
  • 01: folder (page) number
  • 13: file number
  • 30: icon color
  • 3: icon shape

See the previous link about internal storage for more information about the numerical values in file names.

Music Player[edit]

It loads audio files from the SD card. It supports MP3 and AAC-encoded audio files and supports m3u playlists.

Playlist file format[edit]

The application allows for user created playlists. They are stored on the SD card.

Offset Size Description
0x00 0x04 Magic bytes, 'O', 'V', 'A', 'F' or "FAVO" endian corrected.
0x04 0x04 Always integer with value 16
0x08 0x04 File size (0x26730)
0x0C 0x04 Zero Padding
0x10 0x02 checksum (songs?)
0x12 0x02 Icon ID (0-44) if id==-1 then loads custom icon from end of playlist?
0x14 0x02 Song file count
0x16 0x02 Number of possible songs (usually 0x12C/300)
0x18 0x04 Some kind of timestamp, for encryption (doesn't change when editing)
0x1A 0x01 Checksum (icon?, header?) (doesn't change when editing)
0x1B 0x01 Checksum (name?) (doesn't change when editing)
0x1C 0x04 Always(?) integer with value 6
0x20 0x100 (avaiable 0x40) Playlist name stored in UTF-16
0x120+(n*0x20C) => n<300 692 (0x20C per song) File name stored in UTF-16, repeats for the rest of the file
0x2672F - End

Sample reader[edit]

This is a basic example of how to read a 3DS playlist.

/* This is free and unencumbered software released into the public domain.
/* Anyone is free to copy, modify, publish, use, compile, sell, or
/* distribute this software, either in source code form or as a compiled
/* binary, for any purpose, commercial or non-commercial, and by any
/* means.

/* In jurisdictions that recognize copyright laws, the author or authors
/* of this software dedicate any and all copyright interest in the
/* software to the public domain. We make this dedication for the benefit
/* of the public at large and to the detriment of our heirs and
/* successors. We intend this dedication to be an overt act of
/* relinquishment in perpetuity of all present and future rights to this
/* software under copyright law.
/* 
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
/* IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
/* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
/* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
/* OTHER DEALINGS IN THE SOFTWARE.
/*
/* For more information, please refer to <http://unlicense.org/> */

#include <stdio.h>
#include <stdint.h>

uint8_t buf[0x26730];
uint16_t checksum, icon, songCount;
uint32_t timestamp;
uint8_t playlistName[0x100];
uint8_t songName[0x20C][299];

void readUtf16AsAscii(uint8_t *input, uint8_t *output, uint16_t length, uint32_t offset) {
	uint16_t j=0;
	for (j=0; j<length; j++) {
		output[j] = input[(j*2)+offset];
	}
}

int main(int argc, char* argv[]) {
	uint16_t t=0;
	FILE *playlistFile;

	if (argc != 2) {
		printf("Usage: %s FILE\n", argv[0]);
		exit(1);
	}

	if ((playlistFile = fopen(argv[1], "rb")) == NULL) {
		printf("Could not open %s.\n", argv[1]);
		exit(1);
	}

	if (fread(buf, 1, 0x26730, playlistFile) != 0x26730) {
		printf("Could not 0x26730 bytes from %s.\n", argv[1]);
		exit(1);
	}

	if (!((buf[0] = 'O') && (buf[1] = 'V') && (buf[2] = 'F') && (buf[3] = 'A'))) {
		printf("%s is not a 3DS playlist file.\n", argv[1]);
		exit(1);
	}

	checksum  = (buf[0x11] << 8)  | buf[0x10];
	icon      = (buf[0x13] << 8)  | buf[0x12];
	songCount = (buf[0x15] << 8)  | buf[0x14];
	timestamp = (buf[0x17] << 24) | (buf[0x16] << 16) | (buf[0x19] << 8) | buf[0x18];
	readUtf16AsAscii(buf, playlistName, 0x100, 0x20);
	for (t=0; t<songCount; t++) readUtf16AsAscii(buf, songName[t], 0x20C, (0x120+(t*0x20C)));

	printf("Checksum:\t%04X\nIcon ID:\t%04X\nSong Count:\t%04X\nTimestamp:\t%08X\nPlaylist Name:\t\"%s\"\n",
	checksum, icon, songCount, timestamp, playlistName);

	for (t=0; t<songCount; t++) printf("Name of song %03i: %s\n", t, songName[t]);
}