# Lapped transform

**discrete cosine transform with overlapping blocks**

In signal processing, a lapped transform is a type of linear discrete block transformation where the basis functions of the transformation overlap the block boundaries, yet the number of coefficients overall resulting from a series of overlapping block transforms remains the same as if a non-overlapping block transform had been used.wikipedia

20 Related Articles

### Modified discrete cosine transform

**MDCTModulated Lapped Transformtime-domain aliasing cancellation**

The best known example is the modified discrete cosine transform used in the MP3, Vorbis, AAC, and Opus audio codecs.

The modified discrete cosine transform (MDCT) is a lapped transform based on the type-IV discrete cosine transform (DCT-IV), with the additional property of being lapped: it is designed to be performed on consecutive blocks of a larger dataset,

### Daala

More recently, a form of lapped transform has also been used in the development of the Daala video coding format.

As a basic technology Daala uses an unconventional discrete cosine transform with overlapping blocks.

### Signal processing

**signal analysissignalsignal processor**

In signal processing, a lapped transform is a type of linear discrete block transformation where the basis functions of the transformation overlap the block boundaries, yet the number of coefficients overall resulting from a series of overlapping block transforms remains the same as if a non-overlapping block transform had been used.

### Linear map

**linear operatorlinear transformationlinear**

In signal processing, a lapped transform is a type of linear discrete block transformation where the basis functions of the transformation overlap the block boundaries, yet the number of coefficients overall resulting from a series of overlapping block transforms remains the same as if a non-overlapping block transform had been used.

### Discrete transform

**discrete block transformation**

In signal processing, a lapped transform is a type of linear discrete block transformation where the basis functions of the transformation overlap the block boundaries, yet the number of coefficients overall resulting from a series of overlapping block transforms remains the same as if a non-overlapping block transform had been used.

### Basis function

**basis functionsbasisbases**

### Discrete cosine transform

**DCTiDCTinverse discrete cosine transform**

Lapped transforms substantially reduce the blocking artifacts that otherwise occur with block transform coding techniques, in particular those using the discrete cosine transform.

### MP3

**.mp3MP3 downloadMP3 files**

The best known example is the modified discrete cosine transform used in the MP3, Vorbis, AAC, and Opus audio codecs.

### Vorbis

**Ogg VorbisOGGaoTuV**

The best known example is the modified discrete cosine transform used in the MP3, Vorbis, AAC, and Opus audio codecs.

### Advanced Audio Coding

**AACAAC-LCMPEG-4 AAC**

### Opus (audio format)

**OpusOpus audio format.opus**

### Audio codec

**audio codecscodecaudio**

### Video compression picture types

**B-frameP-frameB-frames**

They are used in video coding for coding I-frames in VC-1 and for image coding in the JPEG XR format.

### VC-1

**SMPTE VC1VC-1/WMV3VC1**

They are used in video coding for coding I-frames in VC-1 and for image coding in the JPEG XR format.

### JPEG XR

**HD PhotoJPEG XR / HD PhotoHD**

They are used in video coding for coding I-frames in VC-1 and for image coding in the JPEG XR format.

### Video coding format

**video coding standardsvideo codingvideo coding standard**

More recently, a form of lapped transform has also been used in the development of the Daala video coding format.

### Modulated complex lapped transform

The modulated complex lapped transform (MCLT) is a lapped transform, similar to the modified discrete cosine transform, that explicitly represents the phase (complex values) of the signal.

### G.722.1

**G.722**

The G.722.1 algorithm is based on lapped transform technology, using a Modulated Lapped Transform (MLT), a type of MDCT.

### Thor (video codec)

**ThorThor video codec**

As part of the NETVC work, the Constrained Low-Pass Filter (CLPF) and motion compensation techniques used in Thor were tested in conjunction with the lapped transform coding techniques from the Daala codec.

### Rico Malvar

**Henrique MalvarHenrique S. MalvarHenrique Sarmento Malvar**