KR100268489B1 - Method and apparatus of recording and playing video data and digital video cassette recorder - Google Patents

Abstract

PURPOSE: Recording and reproducing method and device for video information, and a DVCR(Digital Video Cassette Recorder) thereof are provided to record the video information according to an MPEG(Moving Picture Experts Group)-2 coding method and to edit recorded video information by frame unit. CONSTITUTION: A pre-process unit(102) outputs Y:Cb:Cr of 4:2:0 format to a complexity degree calculate unit(108) and a DCT(Discrete Cosine Transform) unit(104). The DCT unit performs DCT by macro block unit. The calculate unit calculates complexity degree for inputting to a macro block quantization step decide unit(112). A quantization unit(106) quantizes an output of the DCT unit by a slice unit for a variable length coding unit(114) by variably length coding the output of the quantization unit. Thus, the coding unit outputs a video stream to a trick play data sampling unit(116), a transport stream packet encoder(118), and a quantization step adjusting unit(110). The encoder forms a transport stream for a track arrange unit(120) to arranges the transport stream by synchronizing block unit. Output of the track arrange unit is inputted to an error correcting encoder(122) for adding an error correcting code. Output of the encoder is inputted to a 24/25 modulator(124) for being channel coded and recorded on a tape.

Description

METHOD AND APPARATUS OF RECORDING AND PLAYING VIDEO DATA AND DIGITAL VIDEO CASSETTE RECORDER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video recording apparatus, and more particularly, to a method and apparatus for compressing and encoding video information using an MPEG (Motion Picture Expert Group) -2 encoding method.

Conventional Digital Video Cassette (DVC) recorders, Advanced Television (ATV) video cassette recorders, etc., record video information on a recording medium after compressing and encoding the video information according to the Amppe-2 coding method.

The Ampl-2 encoding method uses an intra frame encoding method and an inter frame encoding method. The intra frame coding method consists of a series of processes of quantizing the frame after DCT (Discrete Cosine Transform) and variable length coding the result, and a frame encoded with the intra frame coding method is called an I frame. The inter-frame coding method is divided into two types, one of which is a P-frame coding method, which predictively encodes a frame based on the I frame, and compresses a frame encoded according to the P frame coding method. This is called a P frame. The B frame coding method, which is another of the inter frame coding methods, performs predictive coding based on the I frame and the P frame. A frame encoded according to the B frame coding method is called a B frame. Here, the prediction encoding includes a series of processes for detecting a motion vector by detecting interframe activity and encoding the motion vector, and a quantization scale factor is determined by a buffer control. Configure the feedback loop to be adjusted. This predictive encoding process increases the complexity of hardware. This caused the cost of the DVC recorder to the ATV video cassette recorder to increase.

Since the Ampec-2 coding method employs the inter frame coding method as described above, video information compressed with the Amppe-2 coding method cannot be edited in units of frames. Accordingly, in editing the video information recorded through the DVC recorder or the ATV video cassette recorder, it cannot be edited frame by frame.

In addition, compatibility between the DVC recorder and the ATV video cassette recorder, which encodes and records video data in the MPEG-2 encoding method, has been required in the related art.

As described above, the conventional DVC recorder or the ATV video cassette recorder compresses and records video information using the Amppe-2 coding method including the interframe coding method. This caused a cost increase of the DVC recorder to the ATV video cassette recorder and caused the video information recorded through the DVC recorder to the ATV video cassette recorder not to be edited frame by frame.

There was also a need for compatibility between the DVC recorder and the ATV video cassette recorder.

Accordingly, an object of the present invention is to provide a method for compressing and recording video information according to the Amppe-2 coding method, so that the recorded video information can be edited frame by frame, and the video information recording and reproducing method can reduce the cost. And in providing a device.

Another object of the present invention is to provide a DVC recorder that provides compatibility between a DVC recorder and an ATV video cassette recorder among apparatuses for compressing and recording video information according to the Amppe-2 coding scheme.

1 is a block diagram of a video information recording unit of a digital video cassette recorder according to a preferred embodiment of the present invention;

2 is a configuration diagram of 4: 2: 2 video information;

3 is a configuration diagram of 4: 2: 0 video information;

4 is a diagram illustrating an example of dividing video information into slices;

5 illustrates a macroblock of video information;

6 is a diagram illustrating a process of constructing a transport stream;

7 is a configuration diagram of a transport stream packet;

8 is a diagram illustrating an example of arranging two transport stream packets in five sync blocks;

9 is a track arrangement diagram of a tape in a conventional ATV video tape recorder.

10 is a track arrangement diagram of a tape according to a preferred embodiment of the present invention;

Fig. 11 is a block diagram of a video information reproducing unit of a digital video cassette recorder in accordance with a preferred embodiment of the present invention.

According to an aspect of the present invention, there is provided a recording method comprising: receiving an intra frame encoding video information, transforming the intra frame encoded video information into a transport stream, and transforming the transport stream into a transport stream; The process of recording the stream on the recording medium.

A reproduction method of the present invention for achieving the above object is a process of reading the video information from a recording medium on which a transport stream for intra frame encoded video information is recorded, and transporting the read video information to a transport stream. Decoding and converting the intra frame encoded video information into intra frame encoded video information; and performing intra frame decoding on the intra frame encoded video information.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description and the annexed drawings, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent to those skilled in the art that the present invention may be practiced without these specific details. And a detailed description of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

According to the present invention, an apparatus for compressing and encoding video information using an MPEG-2 coding method and then recording the video information onto a recording medium, wherein the video information is compressed and encoded only using the intra frame coding method. In other words, the inter frame encoding method for inter-frame prediction encoding is not used. Accordingly, the video information recorded by the device can be edited frame by frame, and the hardware is simplified.

An example in which the present invention is applied to a DVC recorder will be described. In particular, the DVC recorder records video information on a tape according to the tape format employed by the ATV video recorder for compatibility with the ATV video cassette recorder.

The DVC recorder receives a video information according to a National Television System Committee (NTSC), and encodes the data using an intra frame encoding method, and records the data on a tape, and decodes the recorded information by intra frame decoding. And a video information reproducing unit which outputs the video information according to NTSC later.

Referring to FIG. 1, which shows a block diagram of the video information recording unit 100, the preprocessing unit 102 is a video signal according to NTSC, that is, a luminance signal of 4: 2: 2 format Y: red minus luminance chrominance signal Cb : Blue negative luminance color difference signal Cr is input, and is downsampled 1/2 in the vertical direction with respect to the color difference signals Cb and Cr, and output in 4: 2: 0 format.

Here, the format of the video signal according to the NTSC will be described. First, referring to Fig. 2 showing the 4: 2: 2 format, the luminance Y is 720 [pixel] x 480 [pixel], and the color difference signals Cb and Cr are 360 [pixel] x 480 [pixel], respectively. This 4: 2: 2 format video signal is converted into 4: 2: 0 format by the preprocessor 102. Referring to FIG. 3, which shows the 4: 2: 0 format, the luminance Y is 720 [pixels]. ] 480 [pixels], and the color difference signals Cb and Cr are downsampled in the vertical direction, respectively, to 360 [pixels] x 240 [pixels]. The 4: 2: 0 format is divided into first slice to Nth slice as shown in FIG. The slice becomes its unit when quantized. The slice is divided into a plurality of macroblocks, which are composed of four luminance signal Y blocks each consisting of 8 [pixels] × 8 [pixels], one color difference signal Cb, and one color difference signal Cr. do. Referring to FIG. 5 showing the macroblock, the macroblock includes four blocks Y1, Y2, Y3, Y4 for the luminance signal Y, one block Cb for the color difference signal Cb, and one block Cr for the color difference signal Cr. It consists of. The macro block becomes its unit at the time of DCT.

The output of the preprocessor 102, that is, Y: Cb: Cr in 4: 2: 0 format, is input to the complexity calculator 108 and the DCT unit 104. The DCT unit 104 receives the Y: Cb: Cr in the 4: 2: 0 format and performs DCT in macroblock units. In particular, the DCT unit 104 employs the DCT proposed in the amplifier 2. Y: Cb: Cr DCT DCT in macroblock units is input to the quantization unit 106.

The complexity calculator 108 receives the output of the preprocessor 102, that is, Y: Cb: Cr in 4: 2: 0 format, calculates the complexity, and normalizes the calculated complexity. The normalized complexity is input to the macroblock quantization step determiner 112. The macroblock quantization step determination unit 112 determines the initial quantization step for the entire frame based on the normalized complexity. Herein, the Y: Cb: Cr of the 4: 2: 2 format should be fixed-length coded in units of one frame. Accordingly, according to the complexity of the macro block, a target bit to which the macro block should be compressed and allocated is allocated. As described above, the quantization step adjusting unit 110 adjusts the quantization step according to the difference between the allocated target bit and the amount of bits actually generated, and the quantization step adjusting unit 110 is the output bit of the variable length encoder 114. The macroblock quantization step determination unit 112 is controlled according to the difference of the target bit. The macroblock quantization step determiner 112 determines the initial quantization step according to the normalized complexity provided by the complexity calculator 108, and adjusts the quantization step according to the control of the quantization step adjuster 110.

The quantization unit 106 quantizes the output of the DCT unit 104 in units of slices according to the quantization step provided by the quantization step adjustment unit 110. The quantization method adopts the quantization method proposed by the amplifier 2. In particular, the quantization unit 106 processes the two slices separately, and the generation bits of the two slices do not exceed 1.848 [Mbps]. The variable length encoder 114 performs variable length encoding on the output of the quantization unit 106. The table used in the variable length encoding uses a table proposed by the amplifier. The output of the variable length encoder 114 is called a video stream, and the video stream is composed of consecutive I frames. This is because the frames are DCT, quantized, and variable length coded according to the I frame coding scheme. The video stream is input to the trick play data extractor 116, the transport stream packet encoder 118, and the quantization step adjuster 110.

The trick play data extractor 116 extracts only an I frame corresponding to a frame for trick play from an I frame output by the variable length encoder 114. Here, the trick play is largely divided into TPH (Trick Play High Speed) and TPL (Trick Play Low Speed). The TPH is reproduced at -8.5 to 8.5 or -17.5 to 17.5 times. For this purpose, one I frame is repeatedly recorded 18 or 36 times. The TPL is reproduced at 4 times speed, and for this purpose, one I frame is repeatedly recorded twice. The trick play data extractor 116 extracts the I frames for the TPH or TPL and provides them to the transport packet encoder 118 as a video stream.

The transport packet encoder 118 is a video stream composed of I frames for TPH or TPL provided by the trick play data extractor 116 or an I frame during normal play provided by the variable length encoder 114. The video stream and the audio data are muxed to form a transport stream, and the header of the transport stream is configured according to the syntax of the amplifier 2. Referring to FIG. 6 showing the construction of the transport stream of the transport stream packet encoder 118 and FIG. 7 showing the packet construction of the transport stream, first, the I frame of the video stream of FIG. Or I frame in normal play or TPL. The audio stream is configured in units of frames. The I frames are composed of transport streams in combination with audio frames. One transport stream packet of the transport stream is composed of 188 bytes as a header of 4 bytes, an option portion of N bytes, and a payload of 184-N bytes as shown in FIG. The configuration of the transport stream packet is the same regardless of TPH, TPL, and normal play. Such a transport stream can be reproduced through a conventional ATV.

The track arrangement unit 120 receives the transport stream and arranges it in sync blocks, wherein the sync blocks follow the SD format. That is, the track arrangement unit 120 locates two transport stream packets in five sync blocks. Referring to FIG. 8, in which the first and second transport stream packets are disposed in the first to fifth sink blocks SB1 to SB5, each sink block is 90 bytes, of which 2 bytes are sinks. 3 bytes is an ID, 1 byte is a sync block extra header, and a transport stream packet is located in the other part. In FIG. 7, the first transport stream packet is located in the first to third sink blocks SB1 to SB3 including the transport stream packet extra header, and the second transport stream packet includes the transport stream packet extra header. Located in the third to fifth sink blocks SB3 to SB5.

The track arrangement unit 120 indicates information included in the sync block in the sync block extra header. Table 1 shows an example of configuring the sync block extra header according to the preferred embodiment of the present invention.

beat Sync Block 31 ~ Sync Block 155 Sync Block 21 ~ Sync Block 30 7th bit Normal play '0' TPH, TPL '1' ECC3 area '0' Else '1' 6th bit Data / stuffing '0' Toggle Frame '1' Reserved area Reserved area 5th bit Reserved area Sync Block Order 4th bit Third bit 2nd bit 1st bit Reserved area 0th bit

As shown in Table 1, the seventh bit of the sync block extra header for sync block 155 in sync block 31 indicates whether the video transport stream of the sync block is for TPH, TPL or normal play. That is, the track arrangement unit 120 corresponds to the sync block 155 in the sync block 31 and the video transport stream of the sync block is TPH and TPL, and the sync block 31 corresponds to the sync block 31 to the sync block 155. The seventh bit of the extra header is set to 1, and the seventh bit of the sync block extra header is reset to 0 if it is for normal play. The sixth bit of the sync block extra header for the sync block 155 in the sync block 31 indicates whether data or stuffing is located in the sync block or whether a new frame is started and toggled. The second to fifth bits of the sync block extra header for the sync block 155 in the sync block 31 indicate the order of five sync blocks. The seventh bit of the sync block extra header for sync block 30 in sync block 21 indicates whether data for ECC3 or other data is recorded in sync block 30 in sync block 21. In particular, in the preferred embodiment of the present invention, since the video stream is recorded in the sync block 30 in the sync block 21, the most significant bit of the sync block extra header for the sync block 30 in the sync block 21 is represented by '1' to indicate the sync block. In 21, it indicates that the sync block 30 contains no data for ECC3. Here, the bit rate of the sync block 21 to the sync block 30 is 1.848 [Mbps]. Therefore, in the sync block 21, the sync block 30 may store video streams for two slices of the I frames of the normal play.

After the two transport streams are positioned in five sync blocks as described above, the track arrangement unit 120 arranges the transport streams according to a tape format. Here, referring to FIG. 9 showing a tape format of a conventional ATV video cassette recorder and FIG. 10 showing a tape format according to a preferred embodiment of the present invention, the tape formats of the conventional ATV video cassette recorder are F0, F1, It is classified into the format of F2 and has the order of F0, F1, F0, F2, F0, F1, F0, F2, and F0. F0, F1, and F2 represent an ECC2 region of 11 [sink block], a VAUX region of 1 [sink block], a video transport stream packet region of 135 [sink block], and an ECC3 region of 10 [sink block]. And a VAUX area of 2 [sink block], an ECC2 area of 5 [sink block], an audio transport stream packet area of 8 [sink block], an ITI area and the like. In the video transport stream packet region of F0, a TPL video transport stream packet including five sync blocks in which transport stream packets according to TPH are located between sync blocks in which transport stream packets for normal play data are located. Six areas are interspersed. In the video transport stream packet region of F1, a TLH video transport stream packet including 25 sync blocks in which transport stream packets according to TPL are located between sync blocks in which transport stream packets for normal play are located. The area is located. The video transport stream packet region of the F2 includes only a sync block in which a transport stream packet according to normal play is located.

Here, the recording rate of the transport stream packet of the TPH recorded in F0 is 1.122 [Mbps], which is based on Equation 1-A. The recording rate of the transport stream packet of the TPL recorded in F1 is 2.6928 [Mbps], which is based on Equation 1-B.

...(1-A)

... (1-A)

...(1-B)

... (1-B)

The recording rate of the maximum transport stream packet recorded in the video transport stream packet region is 24.948 [Mbps], which is based on Equation (2).

In this way, the transport stream packet recording rate of the TPH and TPL is subtracted from the maximum recording rate of 24.948 [Mbps] in the video transport stream packet area to 21.13 [Mbps], which is the recording rate for normal play data.

Referring to FIG. 10 showing a tape format according to a preferred embodiment of the present invention, the ECC3 region of FIG. 9 is replaced with a video stream region for storing a video stream of a normal play. This is to improve the recording rate for the normal play data and to improve the image quality in the normal play. The video stream area may record video streams for two slices as 10 (sink block). Here, the video stream is an output of the variable length encoder 114.

In the present invention, a video stream corresponding to 448 [pixel] × 720 [pixel] among video data of one frame composed of 480 [pixel] × 720 [pixel] is encoded into a transport stream packet to be encoded as F0, F1, F2. To the video transport stream packet area. The remaining video stream corresponding to 32 [pixels] × 720 [pixels] is recorded in the video stream area without encoding the transport stream packet. When the tape thus recorded is reproduced on an ATV, only a portion corresponding to 448 [pixel] × 720 [pixel] is reproduced in a frame composed of 480 [pixel] × 720 [pixel]. In the case of playback in the DVC recorder according to the preferred embodiment of the present invention, one frame composed of 480 [pixels] × 720 [pixels] is completely played back.

The output of the track arrangement unit 120 is input to the error correction encoder 122. The error correction encoder 112 adds an error correction code presented by the SD to the output of the track arrangement 120. The output of the error correction encoder 112 is input to the 24/25 modulator 124 and channel coded by the SD. The channel coded data is recorded on the tape through a tape recorder (not shown).

Referring to FIG. 11, which shows a block diagram of a video information reproducing unit 200 for intraframe decoding, reproducing and outputting information read from the tape, a reproduction signal provided from a tape reproducing apparatus (not shown) Input to the 24/25 demodulator 202 is channel decoded. The output of the 24/25 demodulator 202 is input to an error correction decoder 204. The error correction decoder 204 error corrects and decodes the output of the 24/25 demodulator 202, and removes and outputs error correction information added during the error correction encoding. The output of the error correction decoder 204 is provided to the track data extracting unit 206. The track data extracting unit 206 extracts the information recorded in the video stream area during normal play and multiplexer 210. Information in which the transport stream packet for normal play is recorded in the video transport stream packet region is extracted and provided to the transport packet decoder 208. The track data extracting unit 206 transmits the information recorded in the TPH transport stream packet region to the transport packet decoder 208 at the time of TPH, and transmits the information recorded in the TPL transport stream packet region to the TPL. To the port packet decoder 208. And such data is also output to the outside for external output.

The transport packet decoder 208 transmits the received information to the multiplexer 210 by decoding the transport packet. In the normal play, the multiplexer 210 muxes the output of the transport packet decoder 208 and the data provided by the track data extractor 206 and provides it to the variable length decoder 21, and the TPH or In TPL, the output of the transport stream decoder 208 is directly provided to the variable length decoder 212. The variable length decoder 212 performs variable length decoding using a table used by the variable length encoder 114 of FIG. 1. The output of the variable length decoder 212 is provided to the inverse quantizer 214. The inverse quantization unit 214 inversely quantizes the output of the variable length decoder 212 and provides the inverse DCT unit 216. The inverse DCT unit 216 takes inverse DCT with respect to the output of the inverse quantization unit 214 and outputs Y: Cb: Cr in 4: 2: 0 format. The 4: 2: 0 format Y: Cb: Cr is input to the post processor 218 and output as Y: Cb, Cr in 4: 2: 2 format.

As described above, according to the present invention, in the apparatus for compressing and recording video information using the MPEG-2 encoding method, the video information is compressed and encoded only using the intra frame encoding method. Therefore, the interframe coding method is not used, and thus hardware can be simplified and frame-by-frame editing can be performed. Further, in recording the video information, recording is made according to the ATV tape format in order to be reproducible to a conventional ATV.

As described above, the present invention has the advantage that the video information can be edited frame by frame even if the video information is compressed and recorded according to the Amppe-2 coding method. In addition, there is an advantage of reducing the cost of the product by omitting inter-frame coding. In addition, there is an advantage that video information recorded by the DVC recorder of the present invention can be reproduced in an ATV video cassette recorder.

Claims (8)

In the video information recording method, Receiving the video information and performing intra frame encoding; Converting the intra frame encoded video information into a transport stream by transport stream encoding; And recording the transport stream on a recording medium. In the video information playback method, Reading the video information from a recording medium on which a transport stream for the intra frame encoded video information is recorded; Transport-stream decoding the read video information and converting the read video information into intra-frame coded video information; And performing intra frame decoding on the intra frame encoded video information to reproduce the intra frame encoded video information. In the video information recording and playback apparatus, An intra frame encoder for intra frame encoding the input video information and outputting the same as a video stream; A transport stream encoder for receiving an output of the intra frame encoder and encoding the output stream into a transport stream; A recording and reading device for recording the output of the transport stream encoder on a recording medium or reading and outputting information recorded on the recording medium; A transport stream decoder configured to receive information read from the recording medium by the recording and reading device and to decode the transport stream; And a transport stream decoder configured to intraframe decode and output the output of the transport stream decoder. In a digital video cassette recorder, A preprocessing unit which receives video information including luminance information and color difference information and vertically downsamples the color difference information; An intra frame encoder for receiving an output of the preprocessor and performing intra frame encoding; A transport stream encoder for receiving an output of the intra frame encoder and audio data and encoding the transport stream; A track arrangement unit arranged in accordance with the format for recording the output of the transport stream encoder on a track of a tape; An error correction decoder for error correcting the output of the track arrangement; A channel coding unit for channel coding the output of the error correction decoder; A recording and reading apparatus for recording the output from the channel coding section onto a tape and reading out information recorded on the tape; A channel decoder for channel decoding the output of the recording and reading device; An error correction decoder for error correction decoding the output of the channel decoding unit; A track data extraction unit for extracting only video information from an output of the error correction decoder; A transport stream decoder for receiving the output of the track data extracting unit and decoding the transport stream; An intra frame decoder for receiving an output of the transport stream decoder and performing intra frame decoding; And a post-processing unit which receives the output of the intra frame decoder and post-processes and outputs the post-processing unit. The apparatus of claim 4, wherein the intra frame encoder; A discrete cosine transforming unit for converting the output of the preprocessing unit in macroblock units; A complexity calculator for calculating the complexity by receiving the output of the preprocessor; A macroblock quantization step determination unit for determining a quantization step as an output of the complexity calculator; A quantization unit for quantizing the output of the discrete cosine transform unit according to the quantization step determined by the macroblock quantization step determination unit; A variable length encoder for variable length encoding the output of the quantizer, And a quantization step adjuster which controls the macroblock quantization step determiner to receive the output of the variable coder and determine the quantization step. The apparatus of claim 4, wherein the intra frame decoder comprises: an intra frame decoder; A variable length decoder for variable length decoding receiving the output of the transport stream decoder; An inverse quantizer for receiving the output of the variable length decoder and inverse quantization; And an inverse discrete cosine converting unit configured to receive an output of the inverse quantization unit and perform inverse discrete cosine transform. The method of claim 4, wherein the format is; A digital video cassette recorder characterized by being a tape recording format of an advanced television video cassette recorder. In a digital video cassette recorder, A preprocessing unit which receives video information including luminance information and color difference information and vertically downsamples the color difference information; An intra frame encoder which receives an output of the preprocessor and outputs an I frame consisting of a normal play I frame and a trick play I frame by performing intra frame encoding; A trick play data extraction unit for extracting a trick play I frame from the I frame; A transport stream encoder for encoding a video stream and a trick play I frame for a predetermined portion of the normal play I frame into a transport stream; A track arrangement unit arranged to record the transport stream for the normal play I frame and the transport stream for the trick play I frame on a track of a tape; An error correction decoder for error correcting the output of the track arrangement; A channel coding unit for channel coding the output of the error correction decoder; A recording and reading apparatus for recording the output from the channel coding section onto a tape and reading out information recorded on the tape; A channel decoder for channel decoding the output of the recording and reading device; An error correction decoder for error correction decoding the output of the channel decoding unit; From the output of the error correction decoder, a transport stream for a predetermined portion of the normal play I frame, a transport stream for the trick play I frame, and a video stream for a portion other than the predetermined portion of the normal play I frame are extracted. A track data extraction section, In the normal play, the track data extracting unit receives a transport stream for a predetermined portion of the normal play I frames from the track data extracting unit, and decodes the transport stream. A transport stream decoder for receiving a transport stream for the transport stream and decoding the transport stream; In normal play, the transport stream decoder muxes and outputs a video stream for a predetermined portion of the normal play I frame and a video stream for a portion other than a predetermined portion of the normal play I frame. A multiplexer for receiving and outputting a trick play I frame from the transport stream decoder; An intra frame decoder which receives the output of the multiplexer and decodes the intra frame; And a post-processing unit which receives the output of the intra frame decoder and post-processes and outputs the post-processing unit.

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