# US 5,703,647 A · Apparatus for encoding/decoding a video signal

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- Number: US 5,703,647 A
- Document ID: US5703647A
- Status: Granted
- Kind: A
- Application number: 08/521,772
- Filed: 1995-08-31
- Granted: 1997-12-30
- Earliest claimed: 1994-08-31
- Assignees: Daewoo Electronics Co., Ltd.
- Inventors: Sang-Ho Kim
- Web page: https://patentgrep.com/patent/US5703647A

## CPC

- H04N 19/85: using pre-processing or post-processing specially adapted for video compression
- H04N 19/115: Selection of the code volume for a coding unit prior to coding
- H04N 19/137: Motion inside a coding unit, e.g. average field, frame or block difference
- H04N 19/152: by measuring the fullness of the transmission buffer
- H04N 19/172: the region being a picture, frame or field
- H04N 19/176: the region being a block, e.g. a macroblock
- H04N 19/44: Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
- H04N 19/60: using transform coding
- H04N 19/146: Data rate or code amount at the encoder output
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

A video signal encoding apparatus performs the quantization based on a predetermined quantizer scale, so the picture quality of an encoded video signal can be maintained. The video signal encoding apparatus sequentially stores an input video frame signals and converts a stored video frame signal from the spatial domain into the frequency domain to provide transform data and quantizes the transform data based on a predetermined quantizer scale to provide quantized transform data. The video signal encoding apparatus statistically codes the quantized transform data to produce an encoded video frame signal and temporarily stores the encoded video frame signal in order to transmit the encoded video frame signal at a constant transmission rate and provides a control signal to thereby enable a video frame signal, being stored at the moment when the transmission of the encoded video frame signal is completed, to be transformed.

## Claims

### Claim 1

An encoding apparatus, for use in a video signal encoder, for encoding an input video signal, the input video signal including a plurality of video frame signals, comprising:
first storage means for sequentially storing the video frame signals on a frame-by-frame basis and, in response to a control signal, for providing a stored video frame signal;
means for transforming the stored video frame signal from the spatial domain into the frequency domain to provide transform data;
means for quantizing the transform data based on a predetermined quantizer scale to provide quantized transform data;
means for statistically coding the quantized transform data to produce an encoded video frame signal;
second storage means for temporarily storing the encoded video frame signal in order to transmit the encoded video frame signal at a constant transmission rate; and
means for providing the control signal based on the encoded video frame signal to thereby enable a video frame signal, being stored in the first storing means at the moment when the transmission of the encoded video frame signal is completed, to be transformed at the transformation means.

### Claim 2 (depends on 1)

The encoding apparatus according to claim 1, wherein said control signal providing means includes:
means for counting the total number of bits of the encoded video frame signal; and
means for calculating the time of completing the transmission of the encoded video frame signal based on the total number of bits and the constant transmission rate and for providing the control signal based on the calculated time.

### Claim 3

An encoding apparatus, for use in a video signal encoder, for encoding an input video signal, the input video signal including a plurality of video frame signals, comprising:
frame grabber means arranged to sequentially store at least one unencoded video frame signal, and provide said at least one unencoded video frame signal in response to a control signal;
coding means arranged to receive said at least one unencoded video frame signal from said frame grabber means and convert it into an encoded video frame signal;
frame buffer means arranged to receive said encoded video frame signal from said coding means, and then transmit the encoded video frame signal at a constant transmission rate B;
controller means arranged to calculate a time T that it takes to transmit the encoded video frame signal from the frame buffer means; and
means for generating said control signal a time T after the frame buffer means begins transmission of the encoded video frame signal; wherein
encoding of a subsequent unencoded video frame signal in the frame grabber means is suspended during transmission of the encoded video frame signal from the frame buffer means.

### Claim 4 (depends on 3)

The encoding apparatus of claim 3, wherein said time T is calculated based on the number of bits in the encoded video frame signal, and the constant transmission rate B.

### Claim 5 (depends on 3)

The encoding apparatus of claim 3, wherein said coding block comprises:
means for transforming the unencoded video frame signal from the spatial domain into the frequency domain to provide transform data;
means for quantizing the transform data based on a predetermined quantizer scale to provide quantized transform data; and
means for statistically coding the quantized transform data to produce an encoded video frame signal.