JP4361340B2 - Digital tv receiver - Google Patents

Description

  The present invention relates to a digital television receiver that receives and demodulates a television broadcast transmitted by digital modulation.

  Conventionally, as the above-described digital television receiver, one that has improved reception performance in an environment where the influence of ghost is large has been proposed (for example, see Patent Document 1).

  FIG. 7 is a block diagram showing a schematic configuration of the digital television receiver disclosed in Patent Document 1. In FIG. A conventional digital television receiver 700 shown in this figure employs a diversity reception system having two systems of an antenna, a tuner, a demodulator, and an error correction circuit. In this case, the antenna 701, the tuner 702, the demodulator 703, and the error correction circuit 704 constitute a first system, and the antenna 801, the tuner 802, the demodulator 803, and the error correction circuit 804 constitute a second system. Each part of the first system and the second system has the same performance. The antenna 701 and the antenna 801 are spaced apart.

  The TSP error detector 705 determines the presence / absence of an error based on the error flag of the MPEG2 transport stream packet output from the error correction circuits 704 and 804, and switches the data selector 706 so that only the packet without error is passed. I do. An error-free packet is input to the MPEG decoding circuit 707, and MPEG2 which is a video and audio encoding method used in digital television broadcasting is decoded. The decoded video and audio signals are input to the video and audio output circuit 708, the video is displayed on a display such as a liquid crystal panel, and the audio is output from a speaker. By having two antennas, a tuner, a demodulator, and an error correction circuit, it is possible to select in real time whichever data is received by the two antennas 701 and 801 and which is in a good reception state, and a good reception state can always be maintained. Has the advantage.

JP 2001-136113 A (3rd page, 4th page, FIG. 1)

  However, the above-described conventional digital television receiver has an advantage that it can select in real time which of the data received by the two antennas is in a good reception state, but the antenna, the tuner, the demodulator, and the error correction circuit. Therefore, there is a problem that it is difficult to reduce the size and power consumption when realizing a digital television receiver that can be mounted on a moving body such as a vehicle. Further, since the effect of diversity reception cannot be obtained unless the two antennas are spatially separated, there is a problem that the entire apparatus becomes large if these antennas are included.

  The present invention has been made in view of the above points, and can always maintain a good reception state without having two systems of an antenna, a tuner, a demodulator, and an error correction circuit. An object of the present invention is to provide a digital television receiver that does not increase in size.

  In order to solve the above problems, a digital television receiver of the present invention includes a wireless communication means for acquiring a transport stream packet received by another digital television receiver by performing wireless communication with the other device, The packet identifiers included in the packet headers of the transport stream packets received by the own device and the transport stream packets received by the wireless communication means from the other device are compared. Selecting means for selecting one of the transport stream packet received by the device and the transport stream packet from the other device, and video data and audio data from the transport stream packet selected by the selecting device And a decoding means for separating and decoding A video and audio reproducing means for reproducing video and audio from the video signal and the audio signal, and a.

  According to this configuration, the same transport stream packet as the transport stream packet received by the own device is acquired by performing wireless communication from another digital television receiver, and these two transport systems are always acquired during the acquisition. Pseudo diversity for selecting one of the stream packets is performed. Thereby, it is possible to always maintain a good reception state. In addition, since one antenna, tuner, demodulator, and error correction circuit are required, the size and power consumption can be reduced.

  Moreover, even a conventional digital television receiver having only one system including an antenna, a tuner, a demodulator, and an error correction circuit and having no diversity reception function can realize a pseudo diversity reception function by adding a few circuits. It becomes possible to improve reception quality between digital television receivers.

  The digital television receiver of the present invention is the above-described digital television receiver, wherein the selection means is a transport stream packet received by the own device and the other device received by the wireless communication means. The transport stream packet received by each of the own device and the other device is synchronized using the continuity index information included in the packet header of each of the transport stream packets, and each transport stream packet is in that state. Any one of the transport stream packets may be selected based on the transport error index information included in the packet header.

  According to this configuration, since the transport stream packet received by the own device and the transport stream packet acquired from the other device are synchronized at the packet level, one of them is selected, so accurate diversity reception is possible. It is possible to enjoy video and audio with always good image quality and sound quality.

  In the digital television receiver of the present invention, in the digital television receiver described above, the wireless communication unit may transmit a transport stream packet received by the own device to the other device.

  According to this configuration, since the transport stream packet received by the own device is transmitted to the other device, when the other device has the same pseudo diversity function as the own device, the other device also performs the pseudo operation. It is possible to enjoy video and audio with always good image quality and sound quality by performing diversity reception.

  Also, in the digital television receiver of the present invention, in the digital television receiver described above, the wireless communication means uses a packet identifier included in a packet header of a transport stream packet containing information of a program desired by the user of the device. You may transmit toward the said other machine.

  According to this configuration, since the packet identifier of the transport stream packet received by the own device is notified to the other device, even if the program received by the own device is different from the program received by the other device, Diversity reception can be performed at the port stream packet level.

  In the digital television receiver of the present invention, in the digital television receiver described above, when the wireless communication means receives a packet identifier of a transport stream packet transmitted from the other device, the same packet identifier as the packet identifier is received. A transport stream packet having a packet header including an identifier may be transmitted to the other device.

  According to this configuration, by receiving the packet identifier of the transport stream packet transmitted from the other device, the other device that transmits the transport stream packet having the packet header including the same packet identifier as the packet identifier is transmitted to the other device. Therefore, even when the own device and the other device are receiving different programs, diversity reception can be performed at the transport stream packet level.

  In the digital television receiver according to the present invention, in the digital television receiver described above, the wireless communication unit may perform wireless communication with the other device by a wireless communication method based on a Bluetooth standard.

  According to this configuration, since the communication method using the Bluetooth standard (the used frequency is 2.4 GHz band) is used for wireless communication with the other device, the transport stream packet transmitted from the other device is received. The antenna can be miniaturized, and the influence of the antenna on the overall size of the device can be minimized.

  The digital television broadcast receiving method of the present invention includes a step of obtaining a transport stream packet received by another digital television receiver by performing wireless communication with the other device, and a step from the obtained other device. When the packet identifier included in the packet header of the transport dream packet is equal to the packet identifier included in the packet header of the transport stream packet received by the own device, the transport stream packet received by the own device And a step of selecting one of the transport stream packets from the other device, and a step of reproducing video and audio from the selected transport stream packet.

  According to this method, the same transport stream packet as the transport stream packet received by the own device is acquired from another digital television receiver by radio, and these two systems of transport are always acquired during the acquisition. Pseudo diversity for selecting one of the stream packets is performed, so that a good reception state can be maintained at all times, and the antenna, tuner, demodulator, and error correction circuit are only required for one system. In addition, low power consumption can be achieved.

  Moreover, even a conventional digital television receiver having only one system including an antenna, a tuner, a demodulator, and an error correction circuit and having no diversity reception function can realize a pseudo diversity reception function by adding a few circuits. It becomes possible to improve reception quality between digital television receivers.

  According to the present invention, instead of preparing two systems of an antenna, a tuner, a demodulator, and an error correction circuit, only one system is prepared, and the other system is used from another digital television receiver. Since the pseudo-diversity is performed by selecting the error-free transport stream packet transmitted from the machine and the transport stream packet received by the own machine, the reception condition is always good. In addition, since only one system is required for the antenna, tuner, demodulator, and error correction circuit, miniaturization and low power consumption can be achieved. Furthermore, even a conventional digital television receiver having only one system including an antenna, a tuner, a demodulator, and an error correction circuit and having no diversity reception function can realize a pseudo diversity reception function by adding only a few circuits. It becomes possible to improve reception quality between digital television receivers.

  In addition, according to the present invention, since the communication method using the Bluetooth standard (the used frequency is 2.4 GHz band) is used for wireless communication with another device, a transport stream packet transmitted from the other device is received. Therefore, it is possible to reduce the size of the antenna, and to minimize the influence of this antenna on the size of the entire device.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing a schematic configuration of a digital television receiver according to Embodiment 1 of the present invention.

  In FIG. 1, a digital television receiver 100 according to the present embodiment includes antennas 101 and 113, a tuner 102, a demodulator 103, an error correction circuit 104, a TS decoding circuit 105, and packet error detection circuits 106 and 108. A continuity index detection circuit 107 and 109, a TS selection circuit 110, a decoding circuit 111, a video and audio output circuit 112, and a wireless communication device 114. The wireless communication device 114 and a control microcomputer (not shown) constitute wireless communication means. The TS selection circuit 110 corresponds to the selection means, the decoding circuit 111 corresponds to the decoding means, and the video and audio output circuit 112 corresponds to the video and audio reproduction means.

  The tuner 102 selects a broadcast wave desired by the user of this apparatus, and inputs an OFDM (Orthogonal Frequency Division Multiplexing) signal of the selected broadcast wave to the demodulator 103. The demodulator 103 demodulates the OFDM signal obtained by channel selection (broadcast wave selection) by the tuner 102 and outputs a transport stream (hereinafter referred to as TS). The error correction circuit 104 performs error detection and error correction on the TS output from the demodulator 103 by error correction processing performed by a transmission apparatus (not shown) on the television broadcast station side.

  The TS decoding circuit 105 refers to a packet identifier (hereinafter referred to as PID) from the TS error-detected and error-corrected by the error correction circuit 104, and refers to a transport stream packet (hereinafter referred to as the service information desired by the user) TS packet) is extracted. Here, the TS is composed of a plurality of TS packets, and each TS packet is composed of a packet header, an adaptation field, and a payload. The packet header includes a PID for identifying the type of TS packet, transport error index information, and continuity index information. By referring to the PID, it is possible to extract a TS packet containing service information desired by this machine user.

  The packet error detection circuit 106 refers to the transport error indicator information included in the packet header of the TS packet extracted by the TS decoding circuit 105 (that is, the TS packet containing the service information desired by the user of the device). Detects whether there is an error in the packet. The continuity index information detection circuit 107 detects continuity index information included in the packet header of the TS packet extracted by the TS decode circuit 105.

  The packet error detection circuit 108 refers to the transport error index information included in the packet header of the TS packet received by the wireless communication device 114 (TS packet is transmitted from the wireless communication device of another digital television receiver). Then, the presence / absence of an error in the TS packet is detected. The continuity index information detection circuit 109 detects continuity index information included in the packet header of the TS packet received by the wireless communication device 114. The TS selection circuit 110 receives the TS packet output from the TS decode circuit 105 and the radio communication device 114 based on the continuity index information detected by the continuity index detection circuit 107 and the continuity index detection circuit 109, respectively. Synchronize the TS packets at the packet level. Then, the one with no error is selected based on the error detection result of the two synchronized TS packets.

  The decoding circuit 111 separates the audio data and the video data from the error-free TS packet selected by the TS selection circuit 110, further decodes the separated audio data and the video data, and outputs an analog audio signal. And play the video signal. The video and audio output circuit 112 includes a liquid crystal display (not shown) and a speaker. The video and audio output circuit 112 outputs audio from the speaker using the audio signal reproduced by the decoding circuit 111. Output.

  The wireless communication device 114 has a function of performing wireless communication using the Bluetooth standard, and reproduces an original signal by despreading a wireless signal modulated by spread spectrum. In this case, the wireless communication device 114 receives a wireless signal transmitted from a wireless communication device included in another digital television receiver, demodulates the TS packet from the received signal, and converts the demodulated TS packet into the packet error detection circuit 108, The data are input to the continuity index detection circuit 109 and the TS selection circuit 110, respectively.

  The packet error detection circuits 106 and 108, the continuity index detection circuits 107 and 109, the TS selection circuit 110, the antenna 113, and the wireless communication device 114 are the parts that characterize the present invention. The TS packet of the same PID as the TS packet of the PID desired by the user of this device is transmitted from another digital television receiver, and further, the packet error detection circuit 108 detects whether or not there is an error in the received TS packet, The continuity index information detection circuit 109 detects continuity index information in the packet header of the TS packet.

  The packet error detection circuit 106 detects whether there is an error in the TS packet output from the TS decode circuit 105, and the continuity index information detection circuit 107 detects the continuity index information of the packet header of the TS packet. . The TS packet output from the TS decode circuit 105 and the radio communication device 114 are output based on the continuity index information detected by the TS selection circuit 110 in the continuity index detection circuit 107 and the continuity index detection circuit 109, respectively. The TS packets to be synchronized are synchronized at the packet level, and the error detection result of the two synchronized TS packets is selected.

  That is, this unit (digital TV receiver) 100 transmits a TS packet of the same PID as the PID desired by this unit user received by another digital TV receiver within the range that can be received by this unit 100 to the wireless communication device. In 114, pseudo diversity reception is performed to select an error-free TS packet (TS packet of a PID desired by the user of the device) received by the device 100 and the TS packet received by the device 100. As a result, good reception can be performed without having two systems of the antenna 101, the tuner 102, the demodulator 103, and the error correction circuit 104 as in the prior art. In addition, since the antenna 101, the tuner 102, the demodulator 103, and the error correction circuit 104 are sufficient for one system, the size and power consumption of the apparatus 100 can be reduced. Of course, since the frequency used in the Bluetooth standard is the 2.4 GHz band, the antenna 113 can be miniaturized, so that the influence of the antenna 113 on the size of the entire device can be minimized.

  Next, a digital television receiver having a TS packet transmission function for assisting pseudo diversity reception of the digital television receiver 100 will be described. FIG. 2 is a block diagram showing a schematic configuration of the digital television receiver 200. In this figure, parts common to the digital television receiver 100 of FIG.

  As shown in FIG. 2, the digital television receiver 200 has one system including an antenna 101, a tuner 102, a demodulator 103, and an error correction circuit 104, and wireless communication using the Bluetooth standard with the digital television receiver 100. The antenna 201 and the wireless communication apparatus 202 for performing the transmission are converted into a radio signal by the spread spectrum modulation and transmitted from the TS packet output from the TS decoding circuit 105.

  Next, the operation of the digital television receiver 100 of this embodiment will be described. When the user selects a desired channel and performs a channel selection operation, frequency data for receiving the channel is input to the tuner 102 from a control microcomputer (not shown). As a result, the tuner 102 outputs an OFDM signal of a broadcast wave of a channel desired by the user of this apparatus. Then, the OFDM signal output from the tuner 102 is demodulated into digital data by the demodulator 103. Then, error detection and error correction are performed on the demodulated digital data by error correction processing performed on the transmission station side by the error correction circuit 104, and a TS is output in the MPEG2 transport stream format. At this time, if an error that cannot be corrected by the error correction circuit 104 occurs, a flag (transport error index) indicating that the packet contains an error is set in the packet header of the TS packet of the TS. Is done.

  The TS that has passed through the error correction circuit 104 is input to the TS decoding circuit 105, the PID included in the packet header is confirmed, and only the TS packet that transmits the channel desired by this machine user is selected. Then, the selected TS packet is input to the packet error detection circuit 106, the continuity index detection circuit 107, and the TS selection circuit 110, respectively. The packet error detection circuit 106 refers to the transport error index information included in the packet header of the input TS packet and detects the presence / absence of an error in the TS packet.

  The continuity index detection circuit 107 detects the break of the packet by detecting the synchronization byte of the TS packet, confirms the transport error index at a predetermined position, and sends the confirmed transport error index to the TS selection circuit 110. input. Further, the continuity index detection circuit 107 extracts a continuity index at a predetermined position of the TS packet and inputs it to the TS selection circuit 110. Here, since the continuity index designates the order of TS packets having the same PID value, the TS selection circuit 110 selects the PID selected based on the transport error index information and the continuity index information. It is possible to know in which position the packet has an error.

  On the other hand, PID TS packets received from the other digital television receivers 200 received by the wireless communication device 114 are input to the packet error detection circuit 108 and the continuity index detection circuit 109, respectively, and whether there is an error in the TS packets. At the same time, the continuity index information is detected, and the TS selection circuit 110 is notified of which position an error has occurred in the packet.

  When the channel selected by the digital television receiver 100 and the channel selected by the digital television receiver 200 are equal (that is, when the PID is equal), the TS selection circuit 110 of the digital television receiver 100 uses the digital television receiver 100 and the digital This means that two TS packets separated by the spatial distance of the antenna 101 of the television receiver 200 are received. The TS selection circuit 110 selects the TS packet with no error by referring to each transport error index and continuity index. For example, the transport error indicator flag of the TS packet of continuity index “5” received by the digital television receiver 100 is set, and the TS packet of the continuity indicator “5” received by the digital television receiver 200 is transcoded. If the port error indicator flag is not set, the digital television receiver 200 operates to select a TS packet.

  By performing such control, the TS circuit received by each of the digital television receiver 100 and the digital television receiver 200 is input to the decoding circuit 111 with no error. The decoding circuit 111 decodes video, audio data, etc., and inputs the decoded signal to the video and audio output circuit 112, where final video and audio are output.

  As described above, according to the digital television receiver 100 of the present embodiment, the TS packet transmitted from another digital television receiver 200 is received, and the TS packet and the TS packet received by the own device 100 are received. Therefore, it is possible to always maintain a good reception state with one system without requiring two systems for performing diversity reception. In addition, since only one system is required, the entire device can be downsized even if an antenna is included. In addition, power consumption can be reduced compared to the case of having two systems. In particular, by using a communication method using the Bluetooth standard for the wireless communication device 114 (used frequency is 2.4 GHz band), the antenna for receiving transport stream packets transmitted from other devices can be reduced in size, The effect of this antenna on the overall size of the device can be minimized.

  In addition, even a conventional digital television receiver without a diversity reception function can realize a pseudo diversity reception function with only a few additional circuits, and can improve reception quality among a plurality of terrestrial digital television receivers. It becomes possible.

  In the above-described embodiment, the digital television receiver 100 uses two systems of demodulated data, that is, the own device and another device (digital television receiver 200). However, from a plurality of digital television receivers. It is also possible to receive TS data through the wireless communication apparatus. In this case, the possibility of outputting a packet with further error is reduced, and the reception quality is further improved. Further, at this time, it is not necessary to have a plurality of wireless communication devices, and a configuration in which data is handled in a time division manner by a single short-range wireless data communication device may be used.

(Embodiment 2)
FIG. 3 is a block diagram showing a schematic configuration of the digital television receiver according to Embodiment 2 of the present invention. In this figure, portions common to the digital television receiver 100 of FIG. 1 are denoted by the same reference numerals, description thereof is omitted, and different portions are mainly described.

  The digital television receiver 300 of the present embodiment is different from the digital television receiver 100 of FIG. 1 in that the output of the TS decoding circuit 105A is output to the wireless communication device 114A in addition to the TS selection circuit 110. . Since the TS packet is input from the TS decoding circuit 105A, the wireless communication device 114A modulates the TS packet by the communication method according to the Bluetooth standard and transmits the modulated signal from the antenna 113.

  By adopting such a configuration, it is possible to exchange reception of TS packets between a plurality of digital television receivers adopting the same configuration using the wireless communication device 114A, so that all digital television receivers receive reception quality. Can be improved.

(Embodiment 3)
FIG. 4 is a block diagram showing a schematic configuration of the digital television receiver according to Embodiment 3 of the present invention. In this figure, portions common to the digital television receiver 100 of FIG. 1 are denoted by the same reference numerals, description thereof is omitted, and different portions are mainly described.

  The digital television receiver 400 of the present embodiment is provided with a PID transmission circuit 401 for notifying other digital television receiver 500 (see FIG. 5) of the received PID information in FIG. Different from the digital television receiver 100. In this case, needless to say, the PID from the PID transmission circuit 401 is transmitted from the wireless communication device 114B.

  On the other hand, FIG. 5 is a block diagram showing a schematic configuration of the other digital television receiver 500. The digital television receiver 500 has a function of transmitting the received PID TS packet and receiving the PID TS packet transmitted from the digital television receiver 400. This is performed by the communication device 202A. That is, the wireless communication apparatus 202A receives the PID TS packet transmitted from the digital television receiver 400 and inputs it to the TS decode circuit 105, while transmitting the PID TS packet received by the own device 500.

  By adopting such a configuration, it is possible to improve the reception quality of the digital television receiver 400 even when the reception frequencies of the digital television receiver 400 and the digital television receiver 500 are the same and channels are selected with different PIDs. Can do.

(Embodiment 4)
FIG. 6 is a block diagram showing a schematic configuration of a digital television receiver according to Embodiment 4 of the present invention. In this figure, parts common to those of the digital television receiver 400 of FIG. 4 are given the same reference numerals, description thereof is omitted, and different parts are mainly described.

  The digital television receiver 600 according to the present embodiment includes a PID transmission circuit 401 that transmits received PID information from the wireless communication device 114C, and a TS selection circuit that extracts a TS packet extracted from the TS that has passed through the error correction circuit 104. And a TS decode circuit 105C that inputs a TS packet of a PID extracted from a TS that has passed through the error correction circuit 104 based on information received by the wireless communication device 114C to the wireless communication device 114C. This is different from the digital television receiver 400 of FIG.

  By adopting such a configuration, even when the reception frequency is common among a plurality of digital television receivers adopting the same configuration, when a channel with a different PID is selected, the wireless communication device 114C is used to perform PID. By exchanging information and TS packets with each other, it is possible to improve reception quality in all digital television receivers.

  In each of the above-described embodiments, the communication between the own device and the other device is performed by the communication method using the Bluetooth standard. However, any wireless communication method capable of performing neighborhood distance communication may be used. For example, the communication method is not limited to the Bluetooth standard.

  INDUSTRIAL APPLICABILITY The present invention can maintain a good reception state at all times, has an effect of reducing the size and power consumption, and can be applied to a digital television receiver mounted on a vehicle or the like.

1 is a block diagram showing a schematic configuration of a digital television receiver according to a first embodiment of the present invention. 1 is a block diagram showing a schematic configuration of another digital television receiver according to Embodiment 1 of the present invention. FIG. 2 is a block diagram showing a schematic configuration of a digital television receiver according to a second embodiment of the present invention. FIG. 3 is a block diagram showing a schematic configuration of a digital television receiver according to a third embodiment of the present invention. The block diagram which shows schematic structure of the other digital television receiver in Embodiment 3 of this invention. FIG. 4 is a block diagram showing a schematic configuration of a digital television receiver according to a fourth embodiment of the present invention. The block diagram which shows schematic structure of the conventional digital television receiver

Explanation of symbols

100, 200, 300, 400, 500, 600 Digital TV receiver 101, 113, 201 Antenna 102 Tuner 103 Demodulator 104 Error correction circuit 105, 105A, 105C TS decoding circuit 106, 108 Packet error detection circuit 107, 109 Continuity Index detection circuit 110 TS selection circuit 111 Decoding circuit 112 Video and audio output circuit 114, 114A, 114B, 114C, 202, 202A Wireless communication device 401 PID transmission circuit

Claims (6)

A wireless communication means for transmitting a transport stream packet received by the own device to another device receiving a digital television broadcast, and receiving a transport stream packet transmitted from the other device;
Transport stream packet when the equal packet identifier included in the packet header of each transport stream packet from said another device that is receiving the transport stream packet at the wireless communication unit the apparatus itself is received Selecting means for selecting a packet having no error among the transport stream packet received by the own device and the transport stream packet from the other device;
Decoding means for separating and decoding video data and audio data from the transport stream packet selected by the selection means;
A digital television receiver comprising: a video and audio reproduction means for reproducing video and audio from the video signal and audio signal decoded by the decoding means.   The selection means uses continuity index information included in packet headers of the transport stream packet received by the own device and the transport stream packet received by the wireless communication means from the other device. The transport stream packet received by each of the own device and the other device is synchronized, and based on the information of the transport error index included in the packet header of each transport stream packet, the transport stream is The digital television receiver according to claim 1, wherein one of the packets is selected. 2. The digital television receiver according to claim 1 , wherein the wireless communication means transmits a packet identifier included in a packet header of a transport stream packet containing information of a program desired by the user of the own device to the other device. When the wireless communication means receives the packet identifier of the transport stream packet transmitted from the other device, the wireless communication means directs the transport stream packet having a packet header including the same packet identifier to the other device. The digital television receiver according to claim 1 for transmission. It said wireless communication means, the digital television receiver as claimed in any one of claims 1 to 4 performs wireless communication with the other apparatus in a wireless communication system according to the Bluetooth standard. Transmitting the transport stream packet received by the own device to the other device receiving the digital television broadcast, and receiving the transport stream packet transmitted from the other device ;
Determines that it has received the transport stream packet if the transport stream packets the packet identifier included in the packet header of each transport stream packet from receive and have the other machine own apparatus is receiving are equal Selecting a packet having no error from the transport stream packet received by the own device and the transport stream packet from the other device;
Separating and decoding video data and audio data from the selected transport stream packet;
A method for receiving a digital television broadcast, comprising: reproducing video and audio from the decoded video signal and audio signal .

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