KR0181081B1 - Escr generator for system decoder - Google Patents

Abstract

The present invention relates to an apparatus for accurately extracting clock information (ESCR) from a received PES stream and restoring data on the basis of the decoding. In order to solve the problem, the present invention relates to a packet of a PES stream. A PES stream depacketizer and a PES stream depacketizer, each of which is separated into a header and a packet payload, PTS and ESCR are extracted from the PES stream depacketizer. A stream for decoding and storing the packet payload of the PES stream, which is the output of the PES stream depacketizer, and outputting the video signal stored on the basis of the playback pulse signal of the PES stream depacketizer. A decoder is provided to accurately restore video data from a received PES stream during system decoding. There is an effect that it is possible.

Description

ESCR playback device of system decoder

1 is a block diagram schematically illustrating an encoder of a transport stream in an MPEG-2 (ISO / IEC 13818) system.

2 is a diagram illustrating a relationship between an elementary stream, a packetizer, and a PES packet.

3 and 4 are diagrams illustrating a packet configuration and a configuration of a transport stream.

5 is a block diagram of an ESCR playback apparatus of a system decoder according to the present invention.

6 is a block diagram showing in detail the ESCR playback unit of the present invention.

* Explanation of symbols for the main parts of the drawings

500: PES stream depacketizer 600: playback signal generating means

610: decoder clock and divider 620: ESCR playback unit

630: RTS extractor 640: comparator

700: stream decoder 710: elementary stream buffer and decoder

720: Memory 730: D / A conversion and mixing processing unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system decoder, and more particularly, to an apparatus for reproducing an ESCR of a system decoder, which accurately extracts clock information (ESCR) from a received PES stream and restores data based on the same.

First, repeated terms will be described and existing techniques will be described.

ESCR refers to a bit string transmitted after formatting a system clock value in a system encoder in order to meet a time base for decoding a PES stream in the system decoder.

Program Clock Reference (PCR) is a value of the system clock transmitted from the system encoder to meet the time standard at the decoder.

PTS (Presention Time Stamp): A value indicating the playing time of a stream received from a decoder. Decoding Time Stamp (DTS): A value indicating a time for decoding a stream received from a decoder.

An MPEG transport stream is a transport stream that consists of a series of transport packets, each of which is constant at 188 bytes in length. This is a predetermined format for transmitting an elementary stream compressed by MPEG-1, MPEG-2 and other methods to a channel in which a transmission error exists.

Transport streams can be created in a number of ways, but their formats must conform to the system streams specified in ISO / IEC 13818-1 (MPEG-2), and the decoder / re-multiplexer is used for decoding streams, re-multiplexers, etc. It must be configured to operate efficiently. The structure of such a transport stream will be described later.

The MPEG-2 transport stream is known from MPEG-2 Internation Standand (IS), which is currently defined as an international standard, as the final technology for the MPEG system. The official name of MPEG-2 is ITU-T Rec.H.222.0 | ISO / IEC 13818.

There are three major parts of MPEG-2, which are divided into a first part system, a second part video, and a third part audio.

ITU-T Rec.H.222.0 | The system part of ISO / IEC 13818 is a recommendation for the overall field of system layer coding.

Here, system layer coding (hereinafter referred to as system coding) is suitable for transmission or storage by multiplexing not only an audio / video stream compressed by a data compression method of MPEG-1 or MPEG-2, but also user data, etc. as necessary. It relates to a technique for formatting.

The process of receiving multiple bit streams and formatting them into a series of streams is called a system encoder, and the process of unpacking the formatted stream into the original input stream is called a system decoder. .

The formatting rule is called syntax, and the semantics that define the meaning of each part in the process of creating this syntax are called semantics.

Since MPEG system IS prescribes syntax and semantics, which are formatting rules, bit streams should be created according to these rules when encoding at the system encoder, and the system decoder should be configured to decode streams created by these rules. do.

The system encoding is not only a function of combining and combining respective audio / video streams, but also some parameters are inserted in order to reproduce the buffer control and synchronization of each decoded stream in the system decoder in decoding the stream.

In the system encoding method, there are two types of transport stream encoding and program stream encoding. Program streams are primarily used for storage.

For reference, FIG. 1 is a diagram schematically illustrating an encoder of a transport stream in an MPEG-2 system, and a process of creating a transport stream from an audio / video stream through a packetizer.

As shown in the figure, audio and video encoders 11, 12 may assume MPEG-1 or MPEG-2, but MPEG-2 system encoding excludes streams encoded with encoders other than the MPEG family. Hence, it could be a H.261 video encoder, a CCITT G.721 audio encoder, or a unique audio / video encoder used only for specific limited users.

The data encoded by the video and audio encoders 11 and 12 are called elementary streams, which are primarily packetized through respective audio and video packetizers 13 and 14.

The data that has undergone this process is called packetized elementary stream (PES), and the packetizer which makes this PES packet is called PES packetizer.

That is, each audio PES packet made through the audio packetizer 13 and the video packetizer 14 and the video PES packet are input to the TS multiplexer 15 with the transport stream (or program stream). In (15), a program stream and a transport stream are generated and output.

In the end, system encoding is a process of receiving an elementary stream and generating a PES packetizing and transport stream. In other words, the system coding process can be divided into two functions, namely, PES packet and TS / PS multiplexing.

The PES packetizer creates elementary streams into PES packets, and the TS / PS multiplexing process corresponds to a process of generating TS / PS packets from PES packets.

In this MPEG-2 system recommendation, the spec, which is a data format for decoding, does not specify a special encoding process, and there is no separate provision for an application system that may occur from time to time.

Therefore, in the encoding system, the output stream needs to provide an accurate stream that meets the decoder specification specified by the MPEG-2 stream IS. In this encoding process, the method of constructing the encoder and the technique for making an efficient decoder are not standardized. .

In addition, since a method of configuring an encoding decoder or an efficient decoding method of an MPEG system stream format is at the discretion of the user, a technology related thereto is currently being actively studied in the world.

Referring to Figure 2, the configuration of the packet and the packetizer will be described.

All information encoded in the system encoder is transmitted in a packet unit format. As shown in FIG. 3, the basic packet structure includes a header and a payload.

The payload 32 section cuts and inserts the stream into a constant length, and other useful information (eg, time information, address, tag, etc.) is inserted into the header 31 section.

Here, a device for making a packet is called a packetizer, and a device for making a packet by receiving an elementary stream is called a PES packetizer (reference numeral 22 in FIG. 2).

The elementary stream in the system encoder refers to an input stream for performing packetizing (packet making process), and more broadly, a stream in which an encoded stream in any form is input to the system encoder. do.

The packetization of this elementary stream is called PES, and this packet is called a PES packet. This process is illustrated in Figure 2.

The system encoder process may be understood as a process of generating an PES packet by receiving an elementary stream, and then generating a transport stream packet or a program stream packet by receiving the PES packet.

The configuration of the transport stream is made up of transport packets as shown in FIG. 4. The length of the transport packet is always configured equally to 188 bytes.

If the packet length is the same and short, it is easy in multiplexing, re-multiplexing, demultiplexing, receiver fabrication, etc., and has the advantage of low loss in transmission error such as cell loss.

Overall, a transport stream composed of transport packets is suitable for broadcasting using a channel having a large transmission error.

Since the transport stream is composed of short packets of fixed length, it is easy to convert to another stream and minimize the effect of loss such as cellulose.

Referring to FIG. 4, a transport stream shows an example in which an audio PES stream and a video PES stream are configured as transport streams, in which each PES packet is recorded in a transport packet payload portion.

On the other hand, if a program is to be transmitted through a physical channel in which a transmission error exists, an error correction code may be added in units of packets having a fixed length so that a good performance can be applied in the case of terrestrial broadcasting / satellite broadcasting.

The present invention has a structure that can be organically connected to an ATM network applied to a high speed communication network, and the same header and short packet characteristics are easy to implement a receiving system.

The system clock (PCR) is a program clock reference (PCR) value representing the time information accompanying the system encoding. The PCR value is generated based on the system clock in the system encoder.

In this regard, the following describes the constraints of the system clock defined in the MPEG system as a conventional technology and the regulation describing the ESCR information in the MPEG system.

The system clock is a system clock frequency provided to all of the functional blocks constituting the system encoder and must satisfy a constraint such as the expression (a1, a2).

27 MHz-810 Hz ≤ system_clock_frequency ≤ 27 MHz + 810 Hz ---- (a1)

Rate of change in system clock frequency ≤ 75 0 ^-3 Hz / sec ---- (a2)

In the sense of the formula (a1), the system clock frequency allows an error of +,-810 Hz at 27 MHz, which corresponds to a range of +,-0.003% based on 27 MHz.

In addition, even when operating in the range of this error, the clock change should not occur suddenly, which is defined in equation (a2).

In other words, if a clock frequency of 27 MHz is allowed in one second, allowing a change of 0.075 Hz in one second, it means that one clock shifts from the 360 M clock.

In summary, the formulas (a1) and (a2) define the operating frequency range of the system clock and the rate of change of the operating frequency.

ESCR signal is defined in the MPEG system ESCR value is as follows. ESCR is a set of programs (elementary streams having the same reference time) consisting of only one elementary stream in a transport stream. Generally, an audio stream and a video stream are multiplexed so that the decoder can decode each other in synchronization. The reference value is calculated as shown in Equation (2) below.

A program consisting of only one such stream is called a PES stream. In the process of decoding such a PES stream by a decoder, a virtual decoder model is an abbreviation of PES-STD (Packetized Elementary Stream-System Target Decoder). ESCR is a value representing the time input to the model for decoding.

In Equation (2), i means the i th byte and t (i) means that the i th byte is a virtual decoder model in PES-STD (MPEG system). This time value is created by sampling the system_clock_frequency that satisfies the constraints of equations (a1, a2).

In this process, the ESCR consists of a 33-bit ESCR_base expressed in 90 KHz units (system clock frequency / 300) and 9-bit ESCR_ext expressed in 29 MHz units (system clock frequency).

I in ESCR (i) indicates the last byte of data of ESCR_base. As a result, ESCR (i) represents the time when the last byte of ESCR_base data is input to the PES-STD as a system_clock_frequency.

ESCR_base (i) = ((System_Clock_Frequency × t (i) DIV300)% 2 ³³

ESCR_ext (i) = ((System_Clock_Frequency × t (i) DIV1)% 300

ESCR (i) = ESCR_base (i) × 300 + ESCR_ext (i) ---- (2)

(DIV is a truncation operation that makes the remainder zero by an integer division operation, and% is an operation that takes the remainder by a Modulo operation.)

The ESCR data format, 48 bits of the ESCR data format defined in MPEG, is composed of the following fields.

reserved 2 bits ESCR_base [32..30] 3 bits

marker_bit 1 bit ESCR_base [29..15] 15 bits

marker_bit 1 bit ESCR_base [14..0] 15 bits

marker_bit 1 bit ESCR_extension [29..15] 9 bits

marker_bit 1 bit

As described above, the entire ESCR data is composed of 6 bytes, and 2 bits of reserved data and 4 marker_bits are meaningless values and the length of ESCR data having actual information is 42 bits.

On the basis of the above, the transmission timing of the ESCR data will be described. First, as recommended by MPEG, the ESCR data described in the prior art portion should be retransmitted within 0.7 seconds. However, if the time point for retransmission is set at any time within 0.7 seconds, the decoding time becomes long in the overall stream configuration.

In the process of starting the decoding operation in the decoder, the PCR value that receives the setting of the decoder system clock is used, and after stabilizing all clocks of the decoder system, the PES stream is decoded.

However, in the PES system decoder, even if the stream is in the buffer, the PES stream cannot be decoded unless ESCR data is received.

That is, in order for the PES stream to be decoded by the decoder, ESCR data must first be received to set the clock of the PES stream decoder, and then the PES stream must be decoded at a stable time point (after all clock values in the PES stream are stabilized).

Accordingly, an object of the present invention is to provide an apparatus for reproducing an ESCR of a system decoder which correctly decodes clock information (ESCR) so that video data can be restored from a received PES stream during system decoding.

According to the present invention for achieving the above object, in the apparatus for reproducing the ESCR data from the received stream during system decoding, PES for separating the encoded and received transport stream into a packet header and a packet payload of the PES stream, respectively A stream depacketizer 500; Reproduction signal generating means (600) for extracting a PTS and an ECSR from the PES from the PES stream depacketizer (500) and generating a reproduction pulse signal for display based on a comparison between the extracted PTS and the ESCR; Decodes and stores the packet payload of the PES stream, which is the output of the PES stream depacketizer 500, and displays the stored video signal based on the playback pulse signal of the playback signal generating means 600 on a monitor. It characterized in that it comprises a stream decoder 700 for outputting.

Hereinafter, the present invention will be described in detail with reference to the illustrated drawings.

5 is an ESCR playback apparatus diagram of a system decoder according to the present invention, and FIG. 6 is a block diagram illustrating the ESCR playback unit in detail.

5, the ESCR playback apparatus of the present invention comprises a PES stream depacketizer 500, a playback signal generating means 600, and a stream decoder 700.

The PES stream depacketizer 500 separates a transport stream encoded and received by a system encoder (not shown) into a packet header and a packet payload of the PES stream, and the packet header of the separated PES stream is It is provided to the reproduction signal generating means 600 to be described later, and the packet payload of the PES stream is provided to the stream decoder 700 to be described later.

The reproduction signal generating means 600 includes a decoder clock and divider 610, an ESCR reproduction unit 620, a PTS extraction unit 630 and a comparator 640.

The decoder clock and divider 610 is configured to generate a clock required for the decoder and supply it to the apparatus.

The ESCR playback unit 620 is based on the initial ESCR provided by the PES stream depacketizer 500 (particularly, the packet header) and the clock required for the decoder clock and the decoder provided from the divider 610. The ESCR, which is a system clock necessary for decoding, is provided to a comparator 640 to be described later.

The PTS extractor 630 is configured to extract a PTS (information indicating the reproduction time) from the packet header of the PES stream which is the output of the PES stream depacketizer 500 and provide the same to the comparator 640 which will be described later.

The comparator 640 compares the ESCR provided from the ESCR reproducing unit 620 and the PTS provided from the PTS extracting unit 630 to generate a reproduction pulse signal for display at a matched time, thereby generating a system decoder 700 to be described later. It is configured to provide.

In more detail, the ESCR reproducing unit 620 includes a decoder system clock 621, a modular 300 9-bit counter 622, a first comparator 623, a 33-bit counter 624, a combination processing unit 625, and the like. PES stream decoder 626.

The decoder system clock 621 is configured to provide the 27 MHz needed for the decoder to the apparatus of the present invention and the modular 300 9 bit counter 622 described below.

The modular 300 9-bit counter 622 counters the initial ESCR provided from the PES stream depacketizer 500 based on the clock (27 MHz) from the decoder system clock 621, the value being countered below. Configured to provide to the first comparator 623.

In addition, when the modular 300 9-bit counter 622 starts at 0 and reaches a value of 299, the modular 300 9-bit counter 622 sets the value to 0 again at the next clock.

The first comparator 623 compares the value counted from the modular 300 9-bit counter 622 with the reference value 299, and provides the carrier to the 33-bit counter 624 to be described later at the matching time point. It is configured to provide a value counted from the 9-bit counter 622 to the combination processing unit 625 described later.

In addition, the first comparator 623 is incremented by 1 while generating a carrier at the same time as compared with the output of the 100101011 and the 9-bit counter (9-bit previous value of 299).

The reason for this configuration is to calculate the ESCR value in synchronization with the encoder system and the clock.

The 33-bit counter 624 is configured to counter by incrementing the carrier provided from the first comparator 623 by one, and the counter value is provided to the combination processing unit 625 described later.

The combination processing unit 625 performs a PES stream decoder on 42 bits (33 bits _base + 9 bits exe ESCR data) obtained by performing a logical combination of the value counted from the first comparator 623 and the value counted from the 33 bit counter 624. 626 is provided to the comparator 640.

The stream decoder 700 includes an elementary stream buffer and decoder 710, a memory 720, a D / A conversion and mixing processor 730.

The elementary stream buffer and decoder 710 is configured to decode the packet payload of the PES stream, which is the output of the PES stream depacketizer 500, and provide the decoded image data to the memory 720 which will be described later.

The memory 720 stores the decoded image data provided from the elementary stream buffer and the decoder 710 and is configured to restore the stored image data to the D / A conversion and mixing processor 730 to be described later. .

The D / A conversion and mixing processing unit 730 converts the image data, which is a digital signal restored from the memory 720, into an analog signal, and the reproduced pulse signal is applied from the reproduced signal generating means 600 to the converted image signal. And display the video signal on a monitor at the time point.

The present invention configured as described above will be described in detail with reference to preferred embodiments.

First, in the ESCR data configuration, 33 bits of the ESCR_base part and 9 bits of ESCR_exe have a length of 42 bits. The middle 6 bits have 48 bits (6 bytes) by adding a meaningless reserved bit.

In the process of creating an ESCR, time is sampled at system_clock_frequency, so the time between samplings is the inverse of sampling_frequency.

Since this sampled time is represented by 42 bits, it means an integer value of one unit represented by 42 bits. This corresponds to the sampling interval and 42 bits determines the operating range, so the range of time that can be expressed as an ESCR is from 0 seconds to the time interval x maximum value (the maximum integer that can be taken by the ESCR represented by 42 bits).

However, when the maximum value is reached from the value of the ESCR, a modular operation is made to be zero again, so the maximum value of this time does not need to be greatly conscious.

That is, the ESCR value is calculated as frequency × time, so the value of the result is a unitless constant, where frequency is system_clock_frequency, and time is the time t (i) corresponding to the i th byte, and system_clock_ The term frequency means clock frequency as described above.

In Equation (2), t (i), that is, the time corresponding to the i-th byte, indicates the time corresponding to the i-th byte when the time of the 0th byte is 0 (that is, t (i) = 0).

The transmission rate (transmission rate of the transport stream) corresponds to (i / transmission-rate) seconds if it is a value expressed in bytes / second. In Equation (2), the ESCR value is calculated separately by ESCR_base and ESCR_ext, where ESCR_ext is expressed as ESCR_base and the remaining time value is expressed in units of system_clock_frequency (27MHz).

Therefore, if the ESCR value is calculated in units of system clock frequency, it is ESCR_base × 300 + ESCR_ext.

In this way, the ESCR is calculated by dividing the SCR (System_Clock_Frequency), which performs the same function as the MPEG-2 ESCR in the MPEG-1 (ISO / IEC 11172) system, at 90 KHz performed at 1/300 of the MPEG-2 system_clock_frequency. It is calculated to provide compatibility with this MPEG-1 system.

In other words, the MPEG-2 video elementary stream and the MPEG-2 audio elementary stream are transmitted through the MPEG-2 transport stream, and the receiver (decoder) uses the MPEG-1 system decoder and the MPEG-1 video / audio decoder. When decoding, the MPEG-1 system decoder sees only the ESCR_base portion of the ESCR portion of the MPEG-2 transport stream and regards it as SCR of MPEG-1.

In addition, since the MPEG-2 video / audio elementary stream is compatible with each MPEG-1 audio / video stream, the MPEG-2 stream can be decoded by the MPEG-1 decoder.

However, since the ESCR value representing the time input to the PES-STD for the PES stream is targeted to a PES packet consisting of only one elementary stream, the PES stream can be simply decoded by the MPEG-1 system decoder.

In equation (2), the stream_clock_frequency × t (i) is divided by 300 to take only integer values (DIV300 operation), and this is expressed as binary 33 bits by performing modular operation of 2 ^33. ESCR_ext is system_clock. After taking the value of frequency × t (i) (DIV 1 operation), the operation of modular 300 is performed and expressed as 9 bits. Eventually, the ESCR is calculated by the sum of these values, ESCR_base × 300 + ESCR_ext.

Referring to FIG. 5, the PES stream depacketizer 500 separates a transport stream encoded and received by a system encoder into a packet header and a packet payload of a PES stream, and the packet header of the PES stream is an ESCR playback unit. 620 and the PTS extractor 630, respectively, and provide a packet tieload of the PES stream to the elementary stream buffer and the decoder 710.

At this time, the initial ESCR and the RTS exist in the packet header of the PES stream.

The elementary stream buffer and decoder 710 receives the packet payload of the PES stream output from the PES stream depacketizer 500 and decodes the elementary stream into an elementary stream before encoding it, and decodes the decoded elementary stream. Until the reproduction pulse signal is applied from the (640) is stored in the memory (720).

At the same time, the ESCR playback unit 620 uses the initial ESCR value present in the packet header of the PES stream provided by the PES stream depacketizer 500 and the decoder clock and the clock synchronization signal of the divider 610. The ESCR required for the operation of the decoder is reproduced and provided to the comparator 640.

Referring to FIG. 6, in an initial operation, the modular 300 9-bit counter 622 and the 33-bit counter 624 have a value present in the packet header of the initial ESCR (PES stream) provided from the PES stream depacketizer 500. Subsequent operations after loading with a value of) will increase the 9-bit counter by one for each clock of the decoder system clock 621.

That is, in the modular 300 9-bit counter 622, the counter value is provided to the first comparator 623 based on the value of the loaded initial ESCR and the clock (27 MHz) of the decoder system clock 621. Here, the modular 300 9-bit counter 622 starts at 0 and becomes a value of 299, and the period is 300 as setting to 0 again at the next clock.

Accordingly, the first comparator 623 compares the value counted from the modular 300 9-bit counter 622 with the reference value 299, and generates a carrier at the matching time point to provide the 33-bit counter 624.

In addition, the value counted from the modular 300 9-bit counter 622 is provided to the combination processing unit 625. In this case, the value of the ESCR is calculated in synchronization with the encoder system and the clock.

Here, the 33-bit counter 624 counters the carriers provided from the first comparator 623 and provides this value to the combination processor 625. For example, the first comparator 623 compares 100101011 and the output of a 9-bit counter (a 9-bit binary value of 299) and increments by 1 while generating a carrier at the same point in time.

Therefore, in the combination processing unit 625, if the value countered by the first comparator 623 and the value countered by the 33-bit counter 624 are provided in a logical combination (42 bits (33 bits_base + 9 bits_exe)), Discard the previous value and load and save the new value in synchronization with every subsequent system clock.

If the ESCR request signal (detected from the received information) is input while performing this operation, the logically combined value of the combination processing unit 625 is provided to the comparator 640 via the PES stream recorder 626. .

Referring to FIG. 5, on the other hand, the PTS extractor 630 extracts a PTS (information indicating a playback time) from a packet header of a PES stream that is an output of the PES stream depacketizer 500, and extracts the PTS. To be provided to the comparator 640.

Accordingly, the comparator 640 generates a reproduction pulse signal for display at the time when the ESCR provided from the ESCR reproducing unit 620 and the PTS provided from the PTS extracting unit 630 coincide with each other. 730).

The decoded image data provided from the elementary stream buffer and the decoder 710 may be restored and provided to the D / A conversion and mixing processor 730.

Here, the decoded image data is reproduced according to the reproduction pulse signal, and the reproduction pulse signal at this time means to reproduce one frame data of the image signal.

Therefore, the D / A conversion and mixing processor 730 converts the image data, which is a digital signal restored from the memory 720, into an analog signal, and displays the converted image signal on a monitor.

As described above, the present invention has an effect of accurately reconstructing image data based on clock information (ESCR) in a received PES stream during system decoding.

Claims (4)

An apparatus for reproducing ESCR data from a received stream during system decoding, comprising: a PES stream depacketizer (500) for separating the encoded and received transport stream into packet headers and packet payloads of the PES stream; Playback signal generating means (600) for extracting PTS and ESCR from the PES from the PES stream depacketizer (500) and generating a playback pulse signal for display based on a comparison between the extracted PTS and ESCR; Decodes and stores the packet payload of the PES stream, which is the output of the PES stream depacketizer 500, and displays the stored video signal based on the playback pulse signal of the playback signal generating means 600 on a monitor. And a stream decoder (700) for outputting the ES decoder. The apparatus of claim 1, wherein the reproduction signal generating means (600) comprises: a decoder clock and divider (610) for generating and supplying a clock required for the decoder; A system clock for decoding based on an initial ESCR provided in a PES stream (particularly, a packet header) that is an output of the PES stream depacketizer 500, and a clock required for the decoder clock provided by the decoder clock and divider 610. An ESCR playback unit 620 for providing an ESCR; A PTS extraction unit (630) for extracting a PTS (information indicating a playback time) from a packet header of a PES stream which is an output of the PES stream depacketizer 500; Comparing the ECSR provided from the ESCR playback unit 620 and the PTS provided from the PTS extraction unit 630 and a comparator 640 for generating a reproduction pulse signal for display at a matching time point ESCR playback apparatus of a system decoder. 3. The apparatus of claim 2, wherein the ESCR playback section (620) comprises: a decoder system clock (621) for providing a clock (27 MHz) required for the decoder; Modular 300 9-bit counter 622 that counters an initial ESCR provided from PES stream depacketizer 500 based on a clock (27 MHz) from decoder system clock 621 and provides a counter value therefrom. Wow; A first comparator (623) for outputting a counter value from the modular 300 9-bit counter (622), and generating and outputting a carrier at a matching time point as a result of comparing the counter value with a reference value (299); A 33-bit counter 624 for countering the carrier provided from the first comparator 623 and outputting the counter value; A combination processing unit (625) for providing 42 bits (33 bits_base + 9 bits_exeESCR) obtained by performing a logical combination of the value counted from the first comparator (623) and the value counted from the 33 bit counter (624); And a PES stream decoder (626) for decoding and outputting the ESCR from the combination processing unit (625). The elementary stream buffer of claim 1, wherein the stream decoder 700 decodes a packet payload of a PES stream which is an output of the PES stream depacketizer 500, and provides the decoded video data. A decoder 710; A memory 720 for storing the decoded image data provided from the elementary stream buffer and the decoder 710 and reconstructing the stored image data; The image data, which is a digital signal restored from the memory 720, is converted into an analog signal, and the converted image signal is displayed on the monitor when the reproduction pulse signal is applied from the reproduction signal generating means 600. ESR playback apparatus of a system decoder, characterized in that it comprises a D / A conversion and mixing processing unit 730