KR20070050708A - Method for processing image data in mpeg-2 ts in order to not occurring blue screen and digital multimedia broadcasting receiver thereof - Google Patents

Abstract

A method of decoding image data included in a transport stream received by a digital multimedia broadcasting receiver includes checking whether a decoding time stamp (DTS) value of a received transport stream packet is equal to or less than a presentation clock reference (PCR) value, If the DTS value is less than or equal to the PCR value, it is checked whether the continuity counter (CC) value for the received transport stream packet is increased by one more than the CC value for the transport stream packet having the same PID (Packet Identifier) value previously received. And if the CC value for the received transport stream packet is increased by one than the CC value for the previously received transport stream packet, based on an increase amount of DTS values for at least two or more image frames displayed previously. Estimate a new DTS value to estimate the DTS value for the received transport stream packet. Replacing with a DTS value, and decoding the video data included in the received transport stream packet when the PCR value becomes the replaced DTS value.

PCR, DTS, PTS, Digital Multimedia Broadcasting, MPEG-2 TS

Description

TECHNICAL FOR PROCESSING IMAGE DATA IN MPEG-2 TS IN ORDER TO NOT OCCURRING BLUE SCREEN AND DIGITAL MULTIMEDIA BROADCASTING RECEIVER THEREOF}

1 is a configuration diagram of a decoder system defined in ISO / IEC 13818-1;

2 is a block diagram showing the configuration of a digital multimedia broadcasting receiving apparatus according to a preferred embodiment of the present invention;

3 is a flowchart illustrating a process of decoding and displaying a received TS packet in the digital multimedia broadcasting receiving apparatus of FIG. 2.

The present invention relates to digital multimedia broadcasting, and more particularly, to a method for processing image data included in a transport stream, and a digital multimedia broadcasting receiving apparatus.

In satellite digital multimedia broadcasting, H.264 video compression technology efficiently compresses video data in a channel having a limited bandwidth and transmission speed, and MPEG-2 TS (Moving Picture Experts Group) for efficiently transmitting multimedia data. 2 Transport Stream) A transport technique is used. That is, the satellite digital multimedia broadcasting transmitter compresses the video data using H.264 video compression technology, encodes the data, and multiplexes the data using the MPEG-2 TS transmission technology to transmit the data to the satellite. The digital multimedia broadcasting receiver receiving the multiplexed MPEG-2 TS through the satellite demultiplexes it, decodes the image data extracted from the MPEG-2 TS for the desired program, and decompresses the H.264 compressed display. do. In terms of time, the process of decoding and displaying video data extracted from the MPEG-2 TS, the satellite digital multimedia broadcasting transmitter inserts a reference clock PCR (Program Clock Reference) value into the TS packet header, and decodes the time stamp. ) And PTS (Presentation Time Stamp) values are inserted into a packetized elementary stream (PES) packet header. The digital multimedia broadcasting receiving apparatus decodes corresponding video data when the PCR value becomes the DTS value and displays the decoded video data when the PCR value becomes the PTS value. For example, it is assumed that a PCR value of 100, a DTS value of 200, and a PTS value of 300 for a TS packet received by a digital multimedia broadcasting receiver are described with reference to the configuration diagram of FIG. 1.

1 is a block diagram of a decoder system defined in ISO / IEC 13818-1.

The TS stream depacketizer 10 of the decoder system included in the digital multimedia broadcasting receiving apparatus converts PES packets from the received TS stream to the video PES depacketizer 20. The PCR value inserted in the TS packet header is output to the PCR counter 30. The PCR counter 30 counts the PCR value 100 and outputs it to the comparator 60. The video PES depacketizer 20 outputs a header of a PES packet to a DTS / PTS extractor 40 and an elementary stream (ES), that is, image data to be displayed. Buffer the elementary stream buffer & decoder 50. The DTS / PTS extractor 40 extracts the DTS value and the PTS value from the PES packet header and outputs the DTS value and the PTS value to the comparator 60.

When the PCR value input from the PCR counter 30 becomes the DTS value 200 or the PCR value 100 becomes the PTS value 300, the comparator 60 decodes / displays the respective signals corresponding thereto. Block) (70). The decoding / display controller 70 decodes the image data buffered in the elementary stream butter & decoder 50 when receiving a signal from the comparator 60 about the PCR value as the DTS value. The decoded stream memory 80 is stored in the decoded stream memory 80. In addition, when the decoding / display controller 70 receives a signal from the comparator 60 about the PCR value as the PTS value, the decoding / display controller 70 displays the image data decoded and stored in the decoded stream memory 80. To display.

In general, satellite digital multimedia broadcasting is adapted to display a minimum of 15 image frames per second. If this is not satisfied, the viewer perceives a break in the screen. In order to provide seamless digital multimedia broadcasting, loss of video frames should be minimized. For this purpose, errors in video data should be minimized. However, even if there is no error in the image data, if an error occurs in the PCR value, the DTS value, and the PTS value, which are time information used when decoding and displaying the image data in the decoder system of FIG. In addition, errors in time information can result in the loss of at least one image frame or a larger number of successive image frames, which greatly affects the truncation phenomenon.

For example, a digital multimedia broadcasting transmitter transmits a TS packet with a PCR value of 100, a DTS value of 200, and a PTS value of 300, but an error occurs before the digital multimedia broadcasting receiver receives the DTS value. Suppose you got it. Since the received image data has a PCR value larger than the DTS value, the decoder system of FIG. 1 determines that the decoding time has passed and does not decode the image data. In addition, even in the case of the PTS value, if the above error occurs, the image data is not displayed and a screen break occurs.

Accordingly, an object of the present invention is to provide a method for processing video data included in a transport stream received in a digital multimedia broadcasting so that there is no screen dropping, and a digital multimedia broadcasting receiving device accordingly.

In the method for decoding the image data included in the transport stream received by the digital multimedia broadcasting receiver of the present invention for achieving the above object, the Decoding Time Stamp (DTS) value for the received transport stream packet is PCR (Presentation) Checking whether the value is equal to or less than a Clock Reference value, and if the DTS value is equal to or less than a PCR value, a transport stream having a continuity counter (CC) value for the received transport stream packet having the same PID (packet identifier) value previously received. Checking whether the CC value for the received transport stream packet is increased by one than the CC value for the previously received transport stream packet, if the CC value for the received transport stream packet is increased by one or more. Estimate the new DTS value based on the increase of the DTS values for the frame and Replacing the DTS value for the stream packet with the estimated DTS value, and if the PCR value becomes the replaced DTS value, decoding the image data included in the received transport stream packet. It features.

In addition, the method for displaying the video data included in the transport stream received by the digital multimedia broadcasting receiving apparatus checks whether the PTS (Presentation Time Stamp) value for the received transport stream packet is less than the DTS value, the PTS value is Checking whether the CC value for the received transport stream packet is increased by one more than the CC value for the transport stream packet having the same PID value as previously received, and for the received transport stream packet. If the CC value is increased by one than the CC value for the previously received transport stream packet, the received transport stream is estimated by estimating a new PTS value based on an increase amount of PTS values for at least two or more image frames displayed previously. Replacing the PTS value for the packet with the estimated PTS value, and receiving And if the PCR value for the transport stream packet is the replaced PTS value, displaying the video data included in the received transport stream packet and having been decoded.

In addition, the digital multimedia broadcasting reception apparatus, if any one of (a) cause of the PCR value of the received transport stream packet is less than the DTS value and (b) cause of the DTS value is less than the PTS value, the received transport Error determination unit for notifying the occurrence of an error if the CC value for the stream packet is increased by one than the CC value for the transport stream packet having the same PID value previously received, and the DTS for at least two or more image frames displayed before An estimator for estimating a new DTS value and a PTS value based on an increase amount of each of the values and the PTS values, and if the error occurrence is detected through the error determination unit, if the cause of the error is (a), the received transport stream packet Replace the DTS value with the new DTS value estimated through the estimator, and if the cause of error is (b), A control unit for replacing a PTS value for a stream stream packet with a new PTS value estimated through the estimator, and if the PCR value for the received transport stream packet becomes a DTS value replaced by the control unit, the received transport And a reproduction unit for decoding the image data included in the stream packet and displaying the decoded image data when the PCR value becomes the replaced PTS value.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

2 is a block diagram showing the configuration of a digital multimedia broadcasting receiving apparatus according to a preferred embodiment of the present invention.

2 is a block diagram of a decoder system included in a digital multimedia broadcasting receiving apparatus. The TS stream depacketizer 100 outputs a PES packet to a video PES depacketizer 110 in a received TS stream, and transmits a TS packet. The PCR value inserted in the header is output to the PCR counter 120. In addition, the TS stream depacketizer 100 outputs the CC (Continuity Counter) value inserted in the TS packet header to the error discriminating unit 130. The CC value is inserted into the TS packet header as a value that is sequentially increased by one for each TS packet having the same PID (Packet Identifier) value. The CC value does not increase in the case of a payload, that is, a TS packet without video data (when the adaptation_field_control value is 00 or 01). The PCR counter 120 counts the PCR values and outputs them to the error discriminating unit 130.

The video PES depacketizer 110 outputs the header of the PES packet to the DTS / PTS extractor 140, and transmits elementary stream (ES), that is, image data to be displayed, to the elementary stream buffer & decoder 150. Buffer to. The decoded stream memory 160 decodes and stores the image data buffered in the elementary stream buffer & decoder 150 and outputs the decoded image data to the display unit 180 under the control of the controller 170. To display. The elementary stream buffer & decoder 150 and the decoded stream memory 160 are included in the reproducing section in the present invention.

The DTS / PTS extractor 140 extracts the DTS value and the PTS value from the PES packet header and outputs the DTS value and the PTS value to the error discriminator 130. When the PCR value input from the PCR counter 120 becomes a DTS value or the PCR value becomes a PTS value, the error discrimination unit 130 outputs each signal corresponding thereto to the controller 170. In addition, when the PCR value is less than or equal to the DTS value, the error discrimination unit 130 determines that the CC value received from the TS stream depacketizer 100 is greater than the CC value for the TS packet having the same PID value previously received. Check to see if one has increased. The error discrimination unit 130 controls the control unit to signal that an error occurs when the CC value received from the TS stream depacketizer 100 increases by one than the CC value for the TS packet having the same PID value as previously received. Output to (170). The increase of one CC value indicates that the TS packets are received in the correct order. Therefore, the error determining unit 130 determines that there is no error in the TS packet itself, and that an error has occurred in the DTS value that is time information. It is to output to the control unit 170. In addition, the error discrimination unit 130, even when the PTS value is checked to be less than or equal to the DTS value, the CC for the TS packet having the same PID value as the CC value received from the TS stream depacketizer 100 previously received. Check that it is increased by one. The error discrimination unit 130 controls the control unit to signal that an error occurs when the CC value received from the TS stream depacketizer 100 increases by one than the CC value for the TS packet having the same PID value as previously received. Output to (170).

The estimator 190 estimates the new DTS value and the PTS value based on an increase amount of the DTS values and the PTS values for at least two or more image frames displayed previously. In order to estimate a new DTS value and a PTS value, a memory of a predetermined space is required, and the estimator 190 allocates a memory for estimating a new DTS value in the elementary stream buffer & decoder 150. In addition, the estimator 190 allocates a memory for estimating a new PTS value in the decoded stream memory 160. In general, according to the satellite digital multimedia broadcasting standard, the digital multimedia broadcasting receiver is configured to buffer at least three image frames before displaying the broadcasting. Therefore, the estimator 190 may estimate the new DTS value and the PTS value based on this. For example, for estimating a new DTS value, the estimator 190 is already decoded and buffered in the elementary stream buffer & decoder 150 before the received TS packet, that is, the currently received TS packet, is decoded. The DTS values inserted in the headers of the respective PES packets for the three image frames are checked. As a result of the check, if the DTS values are set to 100, 200, and 300, the estimator 190 determines the DTS for the currently received TS packet based on the increased amount of the confirmed DTS values, that is, on the basis of a numerical value increasing by 100. Assume the value is 400. The estimator 190 uses the same method even for the PTS value.

When the controller 170 receives a signal indicating that the PCR value becomes the DTS value from the error discriminator 130, the controller 170 decodes the image data buffered in the elementary stream buffer & decoder 150 to decode the decoded stream memory ( 160). In addition, when the controller 170 receives a signal indicating that the PCR value becomes the PTS value from the error discriminator 130, the controller 170 decodes the stored image data into the decoded stream memory 160. Display via.

In addition, when the controller 170 receives an error occurrence signal for the DTS value from the error discriminator 130, the controller 170 replaces the DTS value for the received TS packet with a new DTS value estimated through the estimator 190. do. Accordingly, when the PCR value counted through the PCR counter 120 becomes the replaced DTS value, the controller 170 decodes the image data buffered in the elementary stream buffer & decoder 150 to decode the decoded stream. It is stored in the memory 160. In addition, when the controller 170 receives an error occurrence signal for the PTS value from the error discriminator 130, the controller 170 replaces the PTS value for the received TS packet with a new PTS value estimated through the estimator 190. do. Accordingly, when the PCR value counted through the PCR counter 120 becomes the replaced PTS value, the controller 170 decodes the image data decoded and stored in the decoded stream memory 160 to the display unit 180. Display through.

3 is a flowchart illustrating a process of decoding and displaying a received TS packet in the digital multimedia broadcasting receiving apparatus of FIG. 2.

The error discriminating unit 130 of FIG. 2 checks whether the DTS value for the received TS packet is equal to or less than the PCR value (S10). As a result of the check, if the DTS value is less than or equal to the PCR value, the error discriminator 130 checks whether the CC value for the received TS packet is increased by one more than the CC value for the TS packet having the same PID value previously received. (S20). As a result of the check, if the CC value for the received TS packet is increased by one than the CC value for the previously received TS packet, the error discriminating unit 130 outputs a signal indicating the occurrence of an error to the controller 170.

Accordingly, the controller 170 estimates a new DTS value through the estimator 190 and replaces the DTS value for the received TS packet with the estimated DTS value (S30). The controller 170 checks whether the PCR value counted through the PCR counter 120 is a DTS value, that is, the replaced DTS value (S40). As a result of the check, if the counted PCR value is a DTS value, the controller 170 decodes the image data buffered in the elementary stream buffer & decoder 150, that is, the image data included in the received TS packet. The decoded stream is stored in the memory 160 (S50).

 On the other hand, when the DTS value is not equal to or less than the PCR value in step S10, when the control unit 170 receives a signal for the PCR value is the DTS value from the error discriminating unit 130, the elementary stream buffer The video data buffered by the decoder 150 is decoded and stored in the decoded stream memory 160.

Next, the error determination unit 130 checks whether the PTS value for the received TS packet is less than or equal to the DTS value (S60). As a result of the check, if the PTS value is less than or equal to the DTS value, the error discriminating unit 130 checks whether the CC value for the received TS packet is increased by one than the CC value for the TS packet having the same PID value previously received. (S70). As a result of the check, if the CC value for the received TS packet is increased by one than the CC value for the previously received TS packet, the error discriminating unit 130 outputs a signal indicating the occurrence of an error to the controller 170.

Accordingly, the controller 170 estimates a new PTS value through the estimator 190 and replaces the PTS value for the received TS packet with the estimated PTS value (S80). The controller 170 checks whether the PCR value counted through the PCR counter 120 is a PTS value, that is, the replaced PTS value (S90). As a result of the check, if the counted PCR value becomes the PTS value, the controller 170 displays the decoded and stored image data in the decoded stream memory 160 through the display unit 180 (S100). On the other hand, if the PTS value is not equal to or less than the DTS value in step S60, the control unit 170 receives a signal indicating that the PCR value is the PTS value from the error discriminating unit 130, the decoded stream memory ( The image data decoded and stored in the display unit 160 are displayed on the display unit 180.

In the above description of the present invention, specific embodiments have been described, but various modifications may be made without departing from the scope of the present invention. Therefore, the scope of the present invention should not be defined by the described embodiments, but should be determined not only by the claims but also by the equivalents of the claims.

According to the present invention as described above, by replacing the error time information in the image data received by the satellite digital multimedia broadcasting receiving apparatus to decode and display the image data in time, it is possible to minimize the loss of the image data There is.

In addition, by minimizing the loss of the image data, there is an effect that can provide a digital multimedia broadcasting without screen interruption or delay phenomenon.

Claims (3)

A method of processing video data included in a transport stream received by a digital multimedia broadcasting reception device, Checking whether a Decoding Time Stamp (DTS) value for the received transport stream packet is equal to or less than a Presentation Clock Reference (PCR) value; If the DTS value is less than or equal to the PCR value, it is checked whether the continuity counter (CC) value for the received transport stream packet is increased by one more than the CC value for the transport stream packet having the same PID (Packet Identifier) value previously received. Process of doing; If the CC value for the received transport stream packet is increased by one than the CC value for the previously received transport stream packet, the new DTS value is based on an increase amount of the DTS values for at least two or more image frames displayed previously. Estimating and replacing a DTS value for the received transport stream packet with the estimated DTS value; And And decoding the video data included in the received transport stream packet when the PCR value becomes the replaced DTS value. A method of processing video data included in a transport stream received by a digital multimedia broadcasting reception device, Checking whether a PTS (Presentation Time Stamp) value for the received transport stream packet is equal to or less than a DTS value; If the PTS value is less than or equal to the DTS value, checking whether the CC value for the received transport stream packet is increased by one than the CC value for the transport stream packet having the same PID value previously received; If the CC value for the received transport stream packet is increased by one than the CC value for the previously received transport stream packet, the new PTS value is based on an increase amount of PTS values for at least two or more image frames displayed previously. Estimating and replacing a PTS value for the received transport stream packet with the estimated PTS value; And And if the PCR value for the received transport stream packet is the replaced PTS value, displaying the decoded image data included in the received transport stream packet. . In the digital multimedia broadcasting receiver, If any one of (a) cause where the PCR value for the received transport stream packet is equal to or less than the DTS value and (b) cause that the DTS value is less than or equal to the PTS value occurs, the CC value for the received transport stream packet is An error determination unit for notifying an error occurrence when the same PID value previously received is increased by one than the CC value for the transport stream packet having a value; An estimator estimating a new DTS value and a PTS value based on an increase amount of each of the DTS values and the PTS values for at least two or more image frames displayed previously; If an error occurrence is detected through the error determination unit, if the cause of the error is (a), the DTS value for the received transport stream packet is replaced with a new DTS value estimated through the estimation unit, and the cause of the error occurrence. (B) a control unit for replacing the PTS value for the received transport stream packet with a new PTS value estimated through the estimator; And If the PCR value for the received transport stream packet is a DTS value replaced by the control unit, decode the image data included in the received transport stream packet, and if the PCR value is the replaced PTS value, decode it. And a playback unit for displaying the image data.

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