VQF

• Extensions: .vqf, .vql, .vqe
• Company: Nippon TT
• Samples: http://samples.mplayerhq.hu/vqf/

VQF files are used to store a stream of TwinVQ encoded audio data.

General Layout

• All (u)intxx fields are stored in big-endian order.

typedef struct vqf_file {
 char magic[4];                       /* "TWIN" */
 char version[8];                     /* e.g. "97012000" */
 uint32 subchunks_size;
 uint8 subchunks[subchunks_size];
 char datamarker[4];                  /* "DATA" */
 uint8 data[data_size];               /* data_size from DSIZ subchunk */
} vqf_file;

typedef struct subchunk {
 char subchunk_id[4];
 uint32 subchunk_size;
 uint8 data[subchunk_size-8];
} subchunk;

Standard Sub-chunks

• Strings are not zero-terminated. The length is defined by the subchunk_size field.

Chunk ID	Contents	Field	Description
COMM	Mandatory information	int32 channel_mode	0: mono, 1: stereo
		int32 bitrate	kbit/s
		int32 samplerate	44: 44100 Hz, 22: 22050 Hz, 11: 11025 Hz
		int32 security_level	always 0
NAME	Song title	char name[]
COMT	Comment	char comment[]
AUTH	Author	char author[]
(c)<space>	Copyright	char copyright[]
FILE	Filename	char filename[]
DSIZ	Data size	uint32 data_size	size of compressed audio data

Extension Sub-chunks

Chunk ID	Contents	Field	Description
ALBM	Album title	char album_title[]
YEAR	Recording date	int16 year	0 means unspecified
		char month	idem
ENCD	Compression date	int16 year	0 means unspecified
		char month	idem
		char day	idem
		char hour	idem
		char minute	idem
		char timeZone	idem
TRAC	Track number	int16 track_number
LYRC	Lyrics	char lyrics[]
GUID	Globally Unique Identifier	uchar guid[16]
ISRC	International Standard Record Code	char isrc[]	Identifier of CD
WORD	Words	char words[]
MUSC	Composer	char composer[]
ARNG	Arranger	char arranger[]
PROD	Producer	char producer[]
REMX	Remixer	char remixer[]
CDCT	Conductor	char conductor[]
SING	Singer	char singer[]
BAND	Band name	char band_name[]
PRSN	Personnel	char personnel[]
LABL	Record label	char record_label[]
NOTE	Liner notes	char liner_notes[]
SCND	Auxiliary information	char aux_info[]
EXTR	reserved
_ID3	Reserved for ID3v2 tags	char id3v2_data[]	Not sure if such files exist; priority for tags conflicting with previous chunks is undefined
_YMH	Reserved chunk
_NTT	Reserved chunk

Supported formats

The official encoder supports the following output formats:

1 channel (mono), 16 bits per sample
samplerate (Hz)	bitrate (kbit/s)	bits/frame
11025	8	371
11025	10	464
22050	20	928
22050	24	1114
22050	32	743
44100	40	1857
44100	48	2229

2 channels (stereo), 16 bits per sample
samplerate (Hz)	bitrate (kbit/s)	bits/frame
11025	16	743
11025	20	928
22050	40	1857
22050	48	2229
22050	64	1486
44100	80	3715
44100	96	4458