Dynamic information storage or retrieval – Condition indicating – monitoring – or testing – Including radiation storage or retrieval
Reexamination Certificate
2000-06-22
2004-07-06
Tran, Thang V. (Department: 2653)
Dynamic information storage or retrieval
Condition indicating, monitoring, or testing
Including radiation storage or retrieval
C369S259000, C369S047300
Reexamination Certificate
active
06760292
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a disc recorder which records coded data to be reproduced in a real time (hereafter, referred to as a real time reproduction data) on a recordable disc-like recording medium and a method of recording the coded data. More particularly, the present invention relates to a disc recorder which records the real time reproduction data having a variable transfer rate, for example, as a result of a compressing and encoding operation, together with another data, on a recordable disc-like recording medium, and a method of recording the data.
2. Description of the Related Art
Conventionally, coded data to be reproduced in a real time(real time reproduction data), for example, such as an audio data, a video data and the like, has been popularly recorded on a recordable disc-like recording medium (hereafter, merely referred to as a disc medium).
Here, in the real time reproduction data, its transfer rate is made variable, for example, as a result of a compressing and encoding operation, in many cases. One of the real time reproduction data having the variable transfer rate is picture data which are compressed and coded by so-called MPEG system.
MPEG will be described below.
The MPEG is detailed in ISO-IEC 11172-2, ITU-T H.262/ISO-IEC 13818-2. Here, it is schematically explained. The MPEG is an abbreviation of a name of an organization (Moving Picture Experts Group) for investigating a moving picture coding standard, which was established in ISO/IEC JTC1/SC2 (International Organization for Standardization/International Electro-technical Commission Joint Technical Commission 1/Special Commission 2, namely, a current SC29), in 1988. This MPEG system prescribes a compression method referred to as MPEG 1 (MPEG Phase 1) or MPEG 2 (MPEG Phase 2). The MPEG 1 (MPEG Phase 1) is a standard targeted for a storage medium of about 1.5 Mbps, and inherits the basic techniques of JPEG intended to encode a still picture and H.261 (standardized in accordance with CCITT, SGXV and a current ITU-T SG15) intended to compress a moving picture having a low transfer rate for a video conference and a video telephone in ISDN, thereby introducing new technology for the storage medium. They are established as ISO/IEC 11172 in August, 1993.
The MPEG is prepared by the combination of several techniques. In the MPEG, basically, a picture signal decoded by a motion compensation and prediction is subtracted from an input picture signal to thereby reduce a portion of a temporal redundancy.
There are three modes of direction of prediction as basic modes, namely, a mode to carry out a prediction from a previous picture, a mode to carry out a prediction from a future picture, and a mode to carry out a prediction from both previous and future pictures. Also, these modes can be switched and used for each macro block (MB) of 16 pixels×16 pixels. The direction of prediction is determined in accordance with a picture type (Picture_Type) given to an input picture. There are three picture types, namely, Predictive-coded picture (P-picture), Bidirectionally predictive-coded picture (B-picture), and Intra-coded picture (I-picture). With regard to the P-picture (Predictive-coded picture), there are two modes of a mode to encode a current macro block by predicting based on a previous picture and a mode to independently encode a current macro block without the prediction. With regard to the B-picture (Bidirectionally predictive-coded picture), there are four modes, namely, a mode to carry out the prediction based on the future picture, a mode to carry out the prediction based on the previous picture, a mode to carry out the prediction based on both the previous and future pictures and a mode to independently encode without the prediction. With regard to the I-picture (Intra-coded picture), all macro blocks are independently coded. Since the I-picture stands for intra-coded picture, the Predictive-coded picture and the Bidirectionally predictive-coded picture can be called as non-intra-coded picture.
In motion compensation, a pattern matching is performed on motion areas for each macro block to thereby detect motion vectors at a half pel accuracy. Then, the prediction is done after the macro block is shifted by an amount corresponding to the size of the detected motion vector. The motion vectors contain a motion vector in horizontal direction and a motion vector in vertical direction. The motion vectors are transmitted as an addition information for a macro block together with a MC (Motion Compensation) mode indicative of a basement of the prediction.
Pictures between an I-picture and the next I-picture are referred to as GOP (Group Of Picture). One GOP typically includes about 15 pictures, when the abbreviation GOP is used in a field of storage medium.,
FIG. 1
shows the basic configuration of a video encoder for compressing and encoding video data, among MPEG encoders for compressing and encoding video data and audio data by using the MPEG system.
In
FIG. 1
, an input digital picture signal is sent to an input terminal
101
. This input picture signal is sent to an arithmetic unit
102
and a motion compensation/prediction unit
111
as described later.
The arithmetic unit
102
calculates a difference between a picture signal decoded by the motion compensation/prediction unit
111
and the input picture signal. The differential picture signal is sent to a DCT(Discrete Cosine Transform) unit
103
.
The DCT unit
103
performs an orthogonal transform on the sent differential picture signal. Here, DCT (Discrete Cosine Transform) implies an orthogonal transform in which an integral transform with a cosine function as an integral core is converted into a discrete transform to finite space. In the MPEG, a two-dimensional DCT is performed on a DCT block of 8×8 obtained by dividing the macro block into 4 sections. Typically, the video signal includes a large amount of low frequency components and a little amount of high frequency components. Therefore, the execution of DCT causes coefficients to be concentrated on the low frequency area. The data (DCT coefficients) obtained by the DCT unit
103
are sent to a quantizing unit
104
.
The quantizing unit
104
quantizes the DCT coefficients from the DCT unit
103
. In this quantization in the quantizing unit
104
, the DCT coefficients are divided by quantization values, which are obtained by weighting a two-dimensional frequency of 8×8 referred to as a quantization matrix in accordance with visual characteristic and then scalar-multiplying the weighted values by a quantization scale. Meanwhile, when the coded data encoded by this video encoder are decoded and inversely quantized by a decoder (expanding and decoding apparatus) in future, values approximating to the original DCT coefficients can be obtained by multiplying the coded data by the quantization values used in the video encoder. The data quantized by the quantizing unit
104
are sent to a variable-length encoding (VLC) unit
105
.
The VLC unit
105
performs variable length encoding on the quantized data from the quantizing unit
104
. The VLC
105
encodes by using DPCM (Differential Pulse Code Modulation) that is one of predictive encodings, for direct current (DC) components of the quantized values. On the other hand, the VLC unit
105
performs on an alternating current (AC) components the so-called Huffman encode, which carries out a so-called zigzag scan from the low frequency area to the high frequency area, and then uses a run length of zero and values of effective coefficients as one event, and further assigns the events having higher occurrence possibilities with codes having shorter length. Also, information of a prediction mode and motion vectors is sent from the motion compensation/prediction unit
111
to the VLC
105
. The VLC unit
105
outputs the information of the prediction mode and the motion vectors together with the variable-length coded data as the addition information of the macro block. The data after the ex
Nath & Associates PLLC
Tran Thang V.
Victor Company of Japan , Limited
LandOfFree
Disc recorder for recording coded data to be reproduced in... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Disc recorder for recording coded data to be reproduced in..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Disc recorder for recording coded data to be reproduced in... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3190271