JP2009071431A - Receiver and transmitter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a receiver and a transmitter having the improved customer satisfaction. <P>SOLUTION: The receiver 200 includes: a reception part 210 for receiving a block including a TS packet with determined reproduction order and an error correction packet; a reproduction control part 260 for controlling the reproduction of the TS packet; and a preprocessing part 220 for outputting the TS packet received by the reception part 210 to the side of the reproduction control part 260. The preprocessing part 220 has: a normal operation mode of outputting the TS packet subjected to error correction processing; and a high-speed operation mode of outputting the TS packet not subjected to the error correction processing. The block is constituted of a plurality of UDP packets with determined transmission order, the plurality of UDP packets are each constituted of the TS packets with continuous reproduction order, and the error correction packet is generated using the TS packets with discontinuous reproduction order. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a receiving apparatus and a transmitting apparatus that receive a data packet in which a reproduction order is determined.

  2. Description of the Related Art Conventionally, communication systems that distribute streaming content such as video data and audio data from a transmission device (for example, a broadcasting station) to a reception device are known. In such a communication system, for example, a protocol such as UDP (User Datagram Protocol) of TCP / IP (Transmission Control Protocol / Internet Protocol) is used. As an encoding technique, a technique (MPEG-2 Video / Audio) defined by MPEG (Moving Picture Expert Group) is used.

  The transmission apparatus packetizes the streaming content encoded by the above-described encoding technique, and acquires a plurality of data packets (for example, TS (Transport Stream) packets).

  Here, generally, in the distribution of streaming content, a multicast technique for distributing data packets from a transmitting device to a plurality of receiving devices is used. In the multicast technique, an automatic repeat request (ARQ: Automatic Repeat request) cannot be used. Therefore, an error correction technique and an interleaving technique are used to suppress reception errors of the receiving apparatus (for example, Patent Document 1).

  In the error correction technique, the transmission device generates an error correction packet using a plurality of data packets, and transmits the error correction packet together with the plurality of data packets. The receiving apparatus performs error correction of the data packet by using the error correction packet after receiving the error correction packet.

  In the interleaving technique, the transmitting apparatus rearranges the data packets in a transmission order different from the reproduction order determined for the data packets. The receiving apparatus rearranges the data packets in accordance with the reproduction order determined for the data packets after receiving a block (interleaved block) composed of a plurality of data packets.

Thus, in the background art, even when packet loss occurs in a burst manner, the receiving apparatus can restore the data packet by a combination of the error correction technique and the interleaving technique.
JP 2006-157636 A

  However, in the error correction technique described above, the receiving device cannot perform error correction until it receives the error correction packet, and therefore cannot reproduce the data packet. Similarly, in the above-described interleaving technique, the receiving apparatus cannot reproduce the data packet until all the data packets included in the interleave block are received.

  Therefore, it is necessary to store the data packet in a buffer or the like from when the receiving device starts receiving the data packet until the receiving device actually reproduces the data packet. In other words, there is a waiting time during which no information (image or sound) is played until the streaming content is actually played after the receiving device starts receiving the streaming content, resulting in a decrease in user satisfaction. End up.

  Therefore, the present invention has been made to solve the above-described problem, and an object of the present invention is to provide a receiving apparatus and a transmitting apparatus that can improve user satisfaction.

  In one aspect of the present invention, the receiving apparatus receives a block including a data packet (for example, a TS packet) in which a reproduction order is determined and an error correction packet for performing error correction of the data packet. (Reception unit 210), a reproduction unit (reproduction control unit 260, drawing unit 270, and audio output unit 280) that reproduces the data packet, and outputs the data packet received by the reception unit to the reproduction unit side A preprocessing unit (preprocessing unit 220), wherein the preprocessing unit outputs a first operation mode (normal operation mode) for outputting the data packet subjected to error correction after receiving the error correction packet; A second operation mode (high-speed operation mode) for outputting the data packet that has not been subjected to error correction before receiving the error correction packet. The packet is composed of a plurality of packet units (for example, UDP packets) whose transmission order is determined, and each of the plurality of packet units is composed of the data packets in which the reproduction order is continuous, The error correction packet is generated using the data packet in which the reproduction order is not continuous.

  According to this feature, the preprocessing unit has a first operation mode for outputting data packets that have been subjected to error correction, and a second operation mode for outputting data packets that have not been subjected to error correction.

  Therefore, the user satisfaction can be improved by reducing the waiting time during which no information is reproduced by operating the preprocessing unit in the second operation mode before receiving all the new blocks.

  Since the packet unit is composed of data packets whose reproduction order is continuous, the amount of information that can be reproduced in the second operation mode increases. Therefore, user satisfaction can be further increased.

  The error correction packet is generated using data packets whose reproduction order is not continuous. Therefore, even if the packet loss occurs in a burst manner and the operation mode is the first operation mode, the data packet is restored without performing the interleaving process for rearranging the data packets in the transmission order different from the reproduction order. Is possible.

  In the above-described feature, the reproduction unit performs static reproduction or slow-down of the data packet output by the preprocessing unit in the second operation mode until the operation mode is switched from the second operation mode to the first operation mode. It is preferable to reproduce by reproduction.

  In the above-described feature, the preprocessing unit operates in the second operation mode before all of the new blocks that are the blocks initially included in new streaming content are received, and all of the new blocks It is preferable to operate in the first operation mode after the signal is received.

  In the above-described feature, it is preferable that the pre-processing unit performs switching from the second operation mode to the first operation mode when the loss of the data packet is detected in the second operation mode.

  In one aspect of the present invention, the receiving device includes a first packet including a data packet with a reproduction order determined and an error correction packet for performing error correction of the data packet, and a data packet with a reproduction order determined. A reception unit that receives at least a second block, a reproduction unit that reproduces the data packet, and a preprocessing unit that outputs the data packet received by the reception unit to the reproduction unit. The processing unit includes: a first operation mode for outputting the data packet after performing error correction using the error correction packet; and a second operation mode for outputting the data packet without performing error correction using the error correction packet. And the receiving unit receives the first block via a first path (for example, path A) and corrects the error. The second block to which no packet is attached is received via the second route (for example, route B), and the preprocessing unit outputs the data packet included in the first block in the first operation mode. In the second operation mode, the data packet included in the second block is output, and the second block includes a plurality of packet units in which a transmission order is determined, and the plurality of packet units Are each constituted by the data packets in which the reproduction order is continuous.

  Preferably, the second block is transmitted after a predetermined time from the first block.

  In one aspect of the present invention, the receiving apparatus transmits the data packet in an error correction adding process for adding an error correction packet for performing error correction of a data packet in which a reproduction order is determined or in a transmission order different from the reproduction order. A receiving unit that receives the block including the data packet subjected to the interleaving process, a reproducing unit that reproduces the data packet, and outputs the data packet received by the receiving unit to the reproducing unit side A pre-processing unit, wherein the pre-processing unit performs an error correction process for correcting an error of the data packet by the error correction packet or a deinterleave process for rearranging the data packet according to the reproduction order. And the error correction process or the deinterleave process is performed. A second operation mode for outputting the data packet that has not been received, and the playback unit is configured so that the pre-processing unit performs the operation until the operation mode is switched from the second operation mode to the first operation mode. The data packet output in the second operation mode is reproduced by still reproduction or slow reproduction.

  In the above-described feature, the preprocessing unit operates in the second operation mode before all of the new blocks that are the blocks initially included in new streaming content are received, and all of the new blocks It is preferable to operate in the first operation mode after the signal is received.

  In the above-described feature, it is preferable that the pre-processing unit performs switching from the second operation mode to the first operation mode when the loss of the data packet is detected in the second operation mode.

  In one aspect of the present invention, the transmitting device adds an error correction packet for performing error correction of the data packet to a data packet with a reproduction order determined, and includes the data packet and the error correction packet. And an error correction giving unit (error correction giving unit 120) for generating the block, and a transmission unit (transmitting unit 130) for sending the block generated by the error correction giving unit, and the transmission order of the blocks is determined. A plurality of packet units, each of the plurality of packet units is configured by the data packets in which the reproduction order is continuous, and the error correction assigning unit is configured to store the data in which the reproduction order is not continuous. The error correction packet is generated using the packet.

  According to the present invention, it is possible to provide a receiving apparatus and a transmitting apparatus that can improve user satisfaction.

  Hereinafter, a communication system according to an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

  However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Therefore, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

[First Embodiment]
(Communications system)
Hereinafter, a communication system according to the first embodiment will be described with reference to the drawings. FIG. 1 is a schematic diagram illustrating a communication system according to the first embodiment. As illustrated in FIG. 1, the communication system includes a transmission device 100 and a reception device 200.

  The transmission device 100 transmits streaming content such as video data and audio data by multicast. For example, the transmission device 100 is a broadcasting station that transmits a plurality of types of streaming content for each channel. Here, the transmission device 100 packetizes the streaming content and transmits it. Details of the transmission device 100 will be described later (see FIG. 4).

  The receiving device 200 receives streaming content from the transmitting device 100. For example, the receiving device 200 is a mobile terminal such as a mobile phone or a PDA. The receiving device 200 may be a fixed terminal such as a PC. Details of the receiving device 200 will be described later (see FIG. 6).

(Protocol stack)
Hereinafter, an example of the protocol stack according to the first embodiment will be described. FIG. 2 is a diagram illustrating an example of a protocol stack according to the first embodiment. In the first embodiment, a case in which MPEG (MPEG-2) is used as an encoding method will be described, but the encoding method is not limited to this.

  As shown in FIG. 2, the protocol stack includes an MPEG Video layer, an MPEG Audio layer, an MPEG TS layer, a UDP layer, an IP layer, a MAC layer, and a physical layer in order from the upper layer.

  The MPEG Video layer is a layer that processes video data according to the content standardized by MPEG-2. For example, the MPEG Video layer performs encoding of video data and decoding of video data.

  The MPEG Audio layer is a layer that processes audio data according to the content standardized by MPEG-2. For example, the MPEG Audio layer performs encoding of audio data and decoding of audio data.

  The MPEG TS layer is a layer for processing encoded streaming content. For example, the MPEG TS layer multiplexes audio data and video data, and packetizes streaming content including audio data and video data. As a result, the MPEG TS layer obtains a TS (Transport Stream) packet (data packet).

  The UDP layer is a layer that adds a unique header and a UDP header to a TS packet. Specifically, the UDP layer adds a unique header to the TS packet as shown in FIG. The unique header includes a reproduction order determined for each TS packet, a sequence number continuously allocated to each TS packet, and the like.

  Subsequently, the UDP layer adds a UDP header to the TS packet to which the unique header is added according to a connectionless protocol (User Data Protocol). The UDP header includes a source port number, a destination port number, a UDP packet length, and the like. A UDP packet (packet unit) to which a UDP header is added is composed of a plurality of TS packets.

  The IP layer is a layer that processes UDP packets in accordance with a connectionless protocol (Internet Protocol). Specifically, as shown in FIG. 3, the IP layer adds an IP header to the UDP packet to which the UDP header is added. The IP header includes a source IP address, a destination IP address, an IP packet length, and the like. For example, the IP layer performs routing control, IP packet segmentation, IP packet reconfiguration, and the like.

  The MAC layer is a layer (Media Access Control Layer) that manages data transmission units (frames) in the physical layer. The frame includes a transmission source MAC address and a destination MAC address in addition to transmission data.

  The physical layer is a layer that transmits and receives frames in accordance with a physical connection method and a physical transmission method. The physical layer may transmit / receive a frame via a wired line or may transmit / receive a frame via a wireless line.

(Transmitter)
The configuration of the transmission apparatus according to the first embodiment will be described below with reference to the drawings. FIG. 4 is a block diagram illustrating a configuration of the transmission device 100 according to the first embodiment.

  As illustrated in FIG. 4, the transmission device 100 includes a streaming content DB 110, an error correction assignment unit 120, and a transmission unit 130. Note that FIG. 4 mainly describes the operations of the MPEG TS layer and the UDP layer.

  The streaming content DB 110 is a database that stores files including streaming content encoded by MPEG-2 Video / Audio. Note that the streaming content DB 110 may store a plurality of files respectively corresponding to a plurality of types of streaming content.

  Here, in order to simplify the description, the streaming content DB 110 will be described assuming that the streaming content is stored in the TS packet format in which the playback order is determined. Accordingly, the streaming content is output from the streaming content DB 110 to the error correction provision unit 120 in the form of TS packets.

  However, the first embodiment is not limited to this. For example, content is stored in the streaming content DB 110, and an encoding unit (not shown) that encodes the content, and a packetizing unit (not shown) that packetizes the content encoded by the encoding unit and obtains TS packets. Etc.) may be included in the transmitting apparatus 100. In such a case, a TS packet is output from the packetizing unit to the error correction adding unit 120.

  As shown in FIG. 5, the error correction assigning unit 120 generates a block including a plurality of TS packets acquired from the streaming content DB 110.

  Here, the block is composed of a plurality of UDP packets in which the transmission order (# 1 to # 16) is determined. The UDP packets are transmitted in ascending order of the numbers shown in FIG.

  Each UDP packet (UDP packet # 1 to UDP packet # 15) is composed of TS packets in which the reproduction order (# 1 to # 105) is continuous. For example, taking UDP packet # 1 as an example, UDP packet # 1 is composed of TS packet # 1 to TS packet # 7. TS packets are reproduced by receiving apparatus 200 in ascending order of numbers shown in FIG.

  The error correction assigning unit 120 generates an error correction packet for performing error correction of the TS packet, using TS packets whose reproduction order is not continuous. Specifically, the error correction giving unit 120 generates an error correction packet using TS packets having the same arrangement position in each UDP packet. For example, the error correction giving unit 120 uses the TS packet # 1, TS packet # 8, TS packet # 15... TS packet # 85, TS packet # 92, and TS packet # 99 to convert the error correction packet # 1. Generate. The UDP packet 16 is composed of error correction packet # 1 to error correction packet # 7.

  Here, the error correction packet is composed of, for example, parity bits. However, the error correction packet is not limited to this, and may be configured by a Reed-Solomon code. In the first embodiment, one error correction packet is assigned to 14 TS packets. However, the present invention is not limited to this.

  The transmission unit 130 transmits the streaming content to the reception device 200 by multicast. Specifically, the transmission unit 130 transmits a block (see FIG. 5) including a TS packet and an error correction packet.

  Taking FIG. 5 as an example, the transmission unit 130 transmits TS packet # 1, TS packet # 2,... TS packet # 104, TS packet # 105, error correction packet # 1,. In this order, TS packets and error correction packets are transmitted.

(Receiver)
Hereinafter, the configuration of the receiving apparatus according to the first embodiment will be described with reference to the drawings. FIG. 6 is a block diagram illustrating a configuration of the receiving device 200 according to the first embodiment.

  As illustrated in FIG. 6, the reception device 200 includes a reception unit 210, a preprocessing unit 220, a separation unit 230, a video decoding unit 240, an audio decoding unit 250, a reproduction control unit 260, and a drawing unit 270. And an audio output unit 280. Note that FIG. 6 mainly describes the operation of the upper layer above the UDP layer.

  The receiving unit 210 receives streaming content from the transmission device 100. Specifically, the reception unit 210 receives a block (see FIG. 5) including a TS packet and an error correction packet.

  Taking FIG. 5 as an example, the receiving unit 210 receives TS packet # 1, TS packet # 2,... TS packet # 104, TS packet # 105, error correction packet # 1,. In this order, TS packets and error correction packets are received.

  The pre-processing unit 220 performs pre-processing required before separating the video data and audio data. Specifically, the preprocessing unit 220 performs normal operation mode (first operation mode) in which a TS packet subjected to error correction after reception of the error correction packet is output, and performs error correction before reception of the error correction packet. And a high-speed operation mode (second operation mode) for outputting TS packets that are not transmitted. Details of the preprocessing unit 220 will be described later (see FIG. 7).

  The separation unit 230 separates data included in the TS packet acquired from the preprocessing unit 220 into video data and audio data (Demultiplex processing). The separation unit 230 outputs the video data to the video decoding unit 240 and outputs the audio data to the audio decoding unit 250.

  The video decoding unit 240 decodes video data based on MPEG-2 Video. The audio decoding unit 250 decodes audio data based on MPEG-2 Audio.

  The reproduction control unit 260 outputs the video data decoded by the video decoding unit 240 to the drawing unit 270, and outputs the audio data decoded by the audio decoding unit 250 to the audio output unit 280.

  Here, the playback control unit 260 performs still playback (still image) or TS packet output from the preprocessing unit 220 in the high speed operation mode until the operation mode of the preprocessing unit 220 is switched from the high speed operation mode to the normal operation mode. The drawing unit 270 is controlled to play back in slow playback (slow image). Specifically, the playback control unit 260 outputs video data acquired from the TS packet output from the preprocessing unit 220 in the high-speed operation mode to the drawing unit 270 and instructs to display a still image or a slow image. The signal is output to the drawing unit 270.

  The drawing unit 270 is connected to a display (not shown), and displays an image on the display using video data acquired from the reproduction control unit 260. Here, the drawing unit 270 displays an image as a still image or a slow image when a control signal for instructing a still image display or a slow image display is acquired.

  That is, the drawing unit 270 reproduces the TS packet output from the preprocessing unit 220 in the high speed operation mode as a still image or a slow image until the operation mode of the preprocessing unit 220 is switched from the high speed operation mode to the normal operation mode.

  The audio output unit 280 is connected to a speaker (not shown), and outputs audio from the speaker using audio data acquired from the reproduction control unit 260.

(Pre-processing section)
Below, the structure of the pre-processing part which concerns on 1st Embodiment is demonstrated, referring drawings. FIG. 7 is a block diagram illustrating a configuration of the preprocessing unit 220 according to the first embodiment.

  As illustrated in FIG. 7, the preprocessing unit 220 includes a buffer 221, a mode switching unit 222, and an error correction unit 223.

  The buffer 221 temporarily stores TS packets and error correction packets received by the receiving unit 210.

  The mode switching unit 222 switches the operation mode of the preprocessing unit 220. Specifically, the mode switching unit 222 changes the operation mode of the preprocessing unit 220 to the high-speed operation mode (second operation mode) when reception of a block (new block) that is initially included in the new streaming content is started. ). The mode switching unit 222 maintains the operation mode of the preprocessing unit 220 in the high-speed operation mode at least until the end of reception of all new blocks.

  On the other hand, the mode switching unit 222 switches the operation mode of the preprocessing unit 220 from the high-speed operation mode (second operation mode) to the normal operation mode (first operation mode) after completion of reception of all new blocks. Here, the mode switching unit 222 sets the operation mode of the preprocessing unit 220 to the high-speed operation mode when TS packets corresponding to a predetermined number of image frames are stored in the buffer 221 after the completion of reception of all the new blocks. May be switched to the normal operation mode.

  Note that the mode switching unit 222 outputs the TS packet to the error correction unit 223 when the operation mode is the normal operation mode. On the other hand, when the operation mode is the high-speed operation mode, the mode switching unit 222 outputs the TS packet directly to the separation unit 230 without passing through the error correction unit 223.

  In addition, when the operation mode is the normal operation mode, the mode switching unit 222 controls the buffer 221 so that all TS packets included in the block are output after completion of the block. On the other hand, when the operation mode is the high-speed operation mode, the mode switching unit 222 controls the buffer 221 so that TS packets are output one by one without waiting for completion of the block.

  The error correction unit 223 performs error correction of the TS packet using the error correction packet. Taking FIG. 5 as an example, the error correction unit 223 uses the error correction packet # 1, TS packet # 1, TS packet # 8, TS packet # 15... TS packet # 85, TS packet # 92, Any error correction of TS packet # 99 is performed.

(Function and effect)
According to the first embodiment, the preprocessing unit 220 outputs a TS mode in which error correction is performed after receiving an error correction packet (first operation mode) and an error before receiving the error correction packet. A high-speed operation mode (second operation mode) for outputting TS packets that have not been corrected.

  The pre-processing unit 220 operates at least in the high-speed operation mode (first operation mode) from the start of reception of a new block until reception of all the new blocks.

  Thus, the drawing unit 270 can display some image (or a part of the image) even before all the new blocks are received.

  Here, in the high-speed operation mode, since error correction is not performed, image distortion may occur. On the other hand, if the operation mode is switched from the high-speed operation mode to the normal operation mode, the image disturbance is eliminated.

  That is, in the first embodiment, even if the image quality is sacrificed to some extent, it is possible to improve user satisfaction by reducing the waiting time.

  According to the first embodiment, the UDP packet is composed of TS packets whose reproduction order is continuous. For example, as described above, the UDP packet # 1 includes the TS packet # 1 to the TS packet # 7. Therefore, when a UDP packet is received, the amount of images that can be displayed in the high-speed operation mode increases, and user satisfaction can be further increased.

  According to the first embodiment, error correction packets are generated using TS packets whose playback order is not continuous. Therefore, even when the packet loss occurs in a burst manner, the TS packet can be restored if the operation mode is the normal operation mode without performing the interleaving process for rearranging the TS packets in the transmission order different from the reproduction order. Is possible.

  According to the first embodiment, the drawing unit 270 displays the TS packet output by the preprocessing unit 220 in the high-speed operation mode as a still image or a slow image. Therefore, when the operation mode is switched from the high-speed operation mode to the normal operation mode, the unnaturalness of the image displayed on the drawing unit 270 can be reduced.

[Second Embodiment]
The second embodiment will be described below with reference to the drawings. In the following, differences between the first embodiment and the second embodiment described above will be mainly described.

  Specifically, in the first embodiment described above, the interleaving process for rearranging TS packets in a transmission order different from the playback order is not performed. On the other hand, in the second embodiment, the transmission device 100 performs an interleaving process in addition to the error correction providing process.

  In the second embodiment, the normal operation mode (first operation mode) is a mode for outputting TS packets subjected to error correction processing and deinterleaving processing, and the high-speed operation mode (second operation mode) is In this mode, TS packets that are not subjected to error correction processing and deinterleaving processing are output.

(Transmitter)
Hereinafter, the configuration of the transmission apparatus according to the second embodiment will be described with reference to the drawings. FIG. 8 is a block diagram illustrating a configuration of the transmission device 100 according to the second embodiment. In FIG. 8, it should be noted that the same components as those in FIG. 4 are denoted by the same reference numerals.

  As illustrated in FIG. 8, the transmission device 100 includes an interleave processing unit 140 in addition to the configuration illustrated in FIG. 4.

  Here, the error correction giving unit 120 described above generates an error correction packet using a plurality of TS packets acquired from the streaming content DB 110. Specifically, the error correction giving unit 120 generates an error correction packet using TS packets having the same arrangement position in each UDP packet. That is, as shown in FIG. 9, the error correction assigning unit 120 generates an error correction packet for performing error correction of the TS packet using a plurality of TS packets whose reproduction order is continuous. For example, the error correction assigning unit 120 generates the error correction packet # 1 using the TS packet # 1 to TS packet # 15.

  The interleaving processing unit 140 rearranges the TS packets in a transmission order different from the reproduction order (interleaving process). Subsequently, as illustrated in FIG. 9, the interleave processing unit 140 generates a block (interleave block) including a plurality of TS packets and error correction packets acquired from the error correction adding unit 120.

  Here, the block is configured by a plurality of UDP packets in which the transmission order (# 1 to # 16) is determined, as in FIG. Note that UDP packets are transmitted in ascending order of the numbers shown in FIG.

  Each UDP packet (UDP packet # 1 to UDP packet # 15) is composed of TS packets whose reproduction order (# 1 to # 105) is not continuous. For example, taking UDP packet # 1 as an example, UDP packet # 1 is composed of TS packet # 1, TS packet # 16... TS packet 76, and TS packet # 91. TS packets are reproduced by receiving apparatus 200 in ascending order of the numbers shown in FIG. The UDP packet 16 is composed of error correction packets # 1 to # 7 as in FIG.

  Taking FIG. 9 as an example, the transmission unit 130 transmits TS packet # 1, TS packet # 16... TS packet # 76, TS packet # 91... TS packet # 90, TS packet # 105, error. TS packet and error correction packet are transmitted in the order of correction packet # 1... Error correction packet # 7.

(Pre-processing section)
Below, the structure of the pre-processing part which concerns on 2nd Embodiment is demonstrated, referring drawings. FIG. 10 is a block diagram illustrating a configuration of the preprocessing unit 220 according to the second embodiment. In FIG. 10, it should be noted that the same components as those in FIG.

  As illustrated in FIG. 10, the preprocessing unit 220 includes a deinterleave processing unit 224 in addition to the configuration illustrated in FIG. 7.

  Here, the mode switching unit 222 described above switches the operation mode of the preprocessing unit 220 as in the first embodiment. Specifically, the mode switching unit 222 changes the operation mode of the preprocessing unit 220 to the high-speed operation mode (second operation mode) when reception of a block (new block) that is initially included in the new streaming content is started. ). The mode switching unit 222 maintains the operation mode of the preprocessing unit 220 in the high-speed operation mode at least until the end of reception of all new blocks.

  Further, the mode switching unit 222 outputs the TS packet to the deinterleave processing unit 224 when the operation mode is the normal operation mode. On the other hand, when the operation mode is the high-speed operation mode, the mode switching unit 222 outputs the TS packet directly to the separation unit 230 without passing through the deinterleave processing unit 224 and the error correction unit 223.

  In the second embodiment, the normal operation mode (first operation mode) is a mode for outputting TS packets subjected to error correction processing and deinterleaving processing, and the high-speed operation mode (second operation mode) is In this mode, TS packets that are not subjected to error correction processing and deinterleaving processing are output.

  In addition, when the operation mode is the normal operation mode, the mode switching unit 222 controls the buffer 221 so that all TS packets included in the block are output after completion of the block. On the other hand, when the operation mode is the high-speed operation mode, the mode switching unit 222 controls the buffer 221 so that a TS packet is output without waiting for completion of the block.

  Here, the mode switching unit 222 determines whether or not the TS packet can be output to the separation unit 230 when the operation mode is the high-speed operation mode. Specifically, it is determined whether or not there is a history in which the TS packet whose playback order is one before the TS packet to be output to the separation unit 230 (output target TS packet) is stored in the buffer 221.

  The mode switching unit 222 determines that the output target TS packet can be output to the separation unit 230 when there is a history in which the TS packet whose playback order is one before the output target TS packet is stored in the buffer 221. On the other hand, the mode switching unit 222 cannot output the output target TS packet to the separation unit 230 when there is no history in which the TS packet whose playback order is one before the output target TS packet is stored in the buffer 221. judge.

  For example, when the playback order of the output target TS packet is “1”, the mode switching unit 222 determines that the output target TS packet can be output to the separation unit 230 on the assumption that the previous block has been received. To do.

  When the playback order of the output target TS packet is “16”, the mode switching unit 222 selects the output target TS packet if there is a history in which the TS packet whose playback order is “15” is stored in the buffer 221. It is determined that the data can be output to the separation unit 230. On the other hand, the mode switching unit 222 determines that the output target TS packet cannot be output to the separation unit 230 if there is no history in which the TS packet whose reproduction order is “15” is stored in the buffer 221.

  As described above, since the mode switching unit 222 determines whether or not the output target TS packet can be output, the consistency of the content reproduced by the TS packet can be achieved even if deinterleaving is not performed. .

  The deinterleave processing unit 224 rearranges the TS packets according to the reproduction order determined for the TS packets (deinterleave processing).

  Note that the playback control unit 260 described above is the TS output from the preprocessing unit 220 in the high speed operation mode until the operation mode of the preprocessing unit 220 is switched from the high speed operation mode to the normal operation mode, as in the first embodiment. The drawing unit 270 is controlled to reproduce the packet as a still image or a slow image. Accordingly, the drawing unit 270 displays the TS packet output by the preprocessing unit 220 in the high speed operation mode as a still image or a slow image until the operation mode of the preprocessing unit 220 is switched from the high speed operation mode to the normal operation mode. Reproduce.

(Function and effect)
According to the second embodiment, the preprocessing unit 220 performs a normal operation mode (first operation mode) for outputting TS packets subjected to error correction processing and deinterleaving processing, and error correction processing and deinterleaving processing. And a high-speed operation mode (second operation mode) for outputting TS packets that are not transmitted.

  The pre-processing unit 220 operates at least in the high-speed operation mode (first operation mode) from the start of reception of a new block until reception of all the new blocks.

  Thus, the drawing unit 270 can display some image (or a part of the image) even before all the new blocks are received. Therefore, even if the quality of the image is sacrificed to some extent, it is possible to improve user satisfaction by reducing the waiting time.

  According to the second embodiment, the drawing unit 270 displays the TS packet output by the preprocessing unit 220 in the high-speed operation mode as a still image or a slow image. Therefore, when the operation mode is switched from the high-speed operation mode to the normal operation mode, the unnaturalness of the image displayed on the drawing unit 270 can be reduced.

[Third Embodiment]
Hereinafter, a third embodiment will be described with reference to the drawings. In the following, differences between the first embodiment, the second embodiment, and the third embodiment described above will be mainly described.

  Specifically, in the first embodiment and the second embodiment described above, streaming content is transmitted from the transmission device 100 to the reception device 200 via a single path. In contrast, in the third embodiment, streaming content is transmitted from the transmission device 100 to the reception device 200 via a plurality of paths.

(Communications system)
In the communication system according to the third embodiment, the transmission device 100 transmits the streaming content to the reception device 200 via the route A and the route B. In the route B, the streaming content is transmitted after a predetermined time from the route A.

  Specifically, the transmission apparatus 100 transmits the streaming content via the path B after delaying the streaming content by a delay buffer or the like for a predetermined time. On the other hand, the transmission device 100 transmits the streaming content via the path A without delaying the streaming content by a delay buffer or the like. Details of the transmission device 100 will be described later (see FIG. 11).

  Here, it is assumed that the streaming content transmitted via the route A and the streaming content transmitted via the route B are streaming corresponding to the same content.

  On the other hand, the receiving device 200 receives streaming content via the path A and receives streaming content via the path B.

(Transmitter)
Hereinafter, a transmission apparatus according to the third embodiment will be described with reference to the drawings. FIG. 11 is a block diagram illustrating a configuration of the transmission device 100 according to the third embodiment. In FIG. 11, it should be noted that the same components as those in FIG.

  As illustrated in FIG. 11, the transmission device 100 includes a first transmission unit 130 </ b> A and a second transmission unit 130 </ b> B instead of the transmission unit 130. The transmitting apparatus 100 includes a delay buffer 150 in addition to the configuration illustrated in FIG.

  The first transmission unit 130A transmits the streaming content to the reception device 200 via the path A. The second transmission unit 130B transmits the streaming content to the reception device 200 via the path B.

  Here, the streaming content transmitted via the path A is configured by a first block including a TS packet on which error correction providing processing and interleaving processing are performed. On the other hand, the streaming content transmitted via the path B is configured by a second block including a TS packet that has not been subjected to the error correction giving process and the interleaving process. That is, in the third embodiment, the route A is the first route, and the route B is the second route.

  The delay buffer 150 delays the streaming content acquired from the streaming content DB 110. That is, the delay buffer 150 delays the second block transmitted from the second transmission unit 130B.

  Here, the delay amount of the second block is preferably determined in consideration of the time during which the receiving apparatus 200 performs the deinterleaving process and the error correction process on the first block corresponding to the second block. Specifically, the timing at which the second block is output from the preprocessing unit 220 of the receiving apparatus 200 is aligned with the timing at which the first block corresponding to the second block is output from the preprocessing unit 220 of the receiving apparatus 200. The delay amount of the second block is preferably determined.

  Accordingly, when the operation mode of the preprocessing unit 220 is switched from the high-speed operation mode to the normal operation mode, the image displayed by the drawing unit 270 is smoothly switched. That is, switching from an image reproduced using the TS packet included in the second block to an image reproduced using the TS packet included in the first block is performed smoothly.

(Receiver)
Hereinafter, a receiving apparatus according to the third embodiment will be described with reference to the drawings. FIG. 12 is a block diagram illustrating a configuration of a receiving device 200 according to the third embodiment. In FIG. 12, it should be noted that the same components as those in FIG.

  As illustrated in FIG. 12, the reception device 200 includes a first reception unit 210 </ b> A and a second reception unit 210 </ b> B instead of the reception unit 210.

  The first reception unit 210A receives the streaming content from the transmission device 100 via the path A. That is, the first reception unit 210A receives the first block constituting the streaming content via the path A.

  The second reception unit 210B receives the streaming content from the transmission device 100 via the path B. That is, the second receiving unit 210B receives the second block constituting the streaming content via the path B.

  When the operation mode is the normal operation mode (first operation mode), the preprocessing unit 220 described above outputs the TS packet included in the first block received by the first reception unit 210A. On the other hand, when the operation mode is the high-speed operation mode (second operation mode), the preprocessing unit 220 outputs the TS packet included in the second block received by the first reception unit 210A.

  Here, as described above, the second block is delayed by the delay buffer 150 and transmitted after a predetermined time from the first block.

  Therefore, even when deinterleaving processing and error correction processing are performed on the first block, the timing at which the first block is output from the preprocessing unit 220 and the second block corresponding to the first block from the preprocessing unit 220 Is mitigated from the timing of output of.

(Function and effect)
According to the third embodiment, the streaming content is transmitted from the transmission device 100 to the reception device 200 via the route A and the route B. That is, the receiving apparatus 200 receives the first block on which the interleaving process and the error correction providing process have been performed via the path A, and the second block on which the interleaving process and the error correction providing process have not been performed via the path B. Receive.

  Therefore, in the high-speed operation mode, an image is reproduced using the TS packet included in the second block, so that it is possible to shorten the waiting time during which no image is displayed and to increase user satisfaction.

  On the other hand, in the normal operation mode, an image is reproduced using the TS packet included in the first block, so that it is possible to suppress deterioration in image quality due to bursty packet loss.

  According to the third embodiment, the second block is delayed by the delay buffer 150 and transmitted after a predetermined time from the first block. Accordingly, the difference between the timing at which the first block is output from the preprocessing unit 220 and the timing at which the second block corresponding to the first block is output from the preprocessing unit 220 is alleviated.

  That is, when the operation mode of the preprocessing unit 220 is switched from the high-speed operation mode to the normal operation mode, the image reproduced using the TS packet included in the second block is reproduced using the TS packet included in the first block. Switching to the image to be performed is performed smoothly.

[Other Embodiments]
Although the present invention has been described with reference to the above-described embodiments, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, a program that causes a computer to execute the operations of the transmission device 100 and the reception device 200 described above may be provided.

  In the above-described embodiment, the example of reproducing video data as a still image or a slow image in switching from the high-speed operation mode to the normal operation mode is illustrated, but the embodiment is not limited to this. Specifically, in switching from the high speed operation mode to the normal operation mode, the audio data may be reproduced by slow reproduction.

  Although not particularly mentioned in the above-described embodiment, there may be three or more routes through which streaming content is transmitted. Further, the route through which the streaming content is transmitted may be any route as long as the route (channel) can be identified. The route for transmitting the streaming content may be either a wired line or a wireless line.

  In the above-described embodiment, the first block includes a TS packet that has been subjected to the error correction giving process and the interleaving process, and the second block includes a TS packet that has not been subjected to the error correction giving process and the interleaving process. The present embodiment is not limited to this. Specifically, the first block includes a TS packet that has been subjected to either error correction providing processing or interleaving processing, and the second block is subjected to either error correction providing processing or interleaving processing. There may be no TS packet.

  Although not particularly mentioned in the above-described embodiment, the mode switching unit 222 may switch from the high-speed operation mode to the normal operation mode when a missing TS packet is detected in the high-speed operation mode.

  You may combine 1st Embodiment and 3rd Embodiment which were mentioned above. Specifically, the reception device 200 receives streaming content from the transmission device 100 via the path A. That is, the receiving apparatus 200 receives the first block on which the error correction providing process according to the first embodiment has been performed via the path A. The receiving device 200 receives streaming content from the transmitting device 100 via the path B. That is, the receiving apparatus 200 receives the second block that has not been subjected to the error correction imparting process according to the first embodiment via the path B.

  When the operation mode is the normal operation mode (first operation mode), the receiving apparatus 200 outputs the TS packet included in the first block. On the other hand, when the operation mode is the high-speed operation mode (second operation mode), the receiving apparatus 200 outputs the TS packet included in the second block.

  The second block may have a block configuration similar to that of the first embodiment. In this case, receiving apparatus 200 may ignore the error correction packet included in the second block and output the TS packet included in the second block without performing error correction in the high-speed operation mode.

1 is a schematic diagram showing a communication system according to a first embodiment. It is a figure which shows an example of the protocol stack which concerns on 1st Embodiment. It is a figure which shows an example of the block which concerns on 1st Embodiment. It is a block diagram which shows the structure of the transmitter 100 which concerns on 1st Embodiment. It is a figure which shows an example of the block which concerns on 1st Embodiment. It is a block diagram which shows the structure of the receiver 200 which concerns on 1st Embodiment. It is a block diagram which shows the structure of the pre-processing part 220 which concerns on 1st Embodiment. It is a block diagram which shows the structure of the transmitter which concerns on 2nd Embodiment. It is a figure which shows an example of the 1st block (interleave block) which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the pre-processing part 220 which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the transmitter which concerns on 3rd Embodiment. It is a block diagram which shows the structure of the receiver 200 which concerns on 3rd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... Transmission apparatus, 110 ... Streaming content DB, 120 ... Error correction provision part, 130 ... Transmission part, 140 ... Interleave processing part, 150 ... Delay buffer, 200 ... Receiving device, 210 ... receiving unit, 220 ... preprocessing unit, 221 ... buffer, 222 ... mode switching unit, 223 ... error correction unit, 224 ... deinterleave processing unit, 230 ... Separation unit, 240 ... Video decoding unit, 250 ... Audio decoding unit, 260 ... Playback control unit, 270 ... Drawing unit, 280 ... Audio output unit

Claims (10)

A receiving unit for receiving a block including a data packet in which a reproduction order is determined and an error correction packet for performing error correction of the data packet;
A reproducing unit for reproducing the data packet;
A pre-processing unit that outputs the data packet received by the receiving unit to the reproducing unit side,
The preprocessing unit outputs a first operation mode for outputting the data packet that has been subjected to error correction after reception of the error correction packet, and the data packet that has not been subjected to error correction before reception of the error correction packet. A second operation mode for outputting,
The block is composed of a plurality of packet units whose transmission order is determined,
Each of the plurality of packet units is configured by the data packets in which the reproduction order is continuous,
The receiving apparatus, wherein the error correction packet is generated using the data packet in which the reproduction order is not continuous.   The reproduction unit reproduces the data packet output by the preprocessing unit in the second operation mode by still reproduction or slow reproduction until the operation mode is switched from the second operation mode to the first operation mode. The receiving device according to claim 1.   The pre-processing unit operates in the second operation mode before all the new blocks that are the first blocks included in the new streaming content are received, and after all the new blocks are received. The receiving apparatus according to claim 1, wherein the receiving apparatus operates in the first operation mode.   The said pre-processing part switches from the said 2nd operation mode to the said 1st operation mode, when the loss of the said data packet is detected in the said 2nd operation mode. Receiver. A receiving unit for receiving a first packet including a data packet in which a reproduction order is determined and an error correction packet for performing error correction of the data packet; and a second block including at least a data packet in which the reproduction order is determined; ,
A reproducing unit for reproducing the data packet;
A pre-processing unit that outputs the data packet received by the receiving unit to the reproducing unit side,
The preprocessing unit includes a first operation mode for outputting the data packet after performing error correction using the error correction packet, and a second operation mode for outputting the data packet without performing error correction using the error correction packet. And
The receiving unit receives the first block via the first path, and receives the second block not provided with the error correction packet via the second path,
The preprocessing unit outputs the data packet included in the first block in the first operation mode, and outputs the data packet included in the second block in the second operation mode;
The second block is composed of a plurality of packet units whose transmission order is determined,
Each of the plurality of packet units is composed of the data packets in which the reproduction order is continuous.   The receiving apparatus according to claim 5, wherein the second block is transmitted with a delay of a predetermined time from the first block. The data packet that has been subjected to an error correction giving process for giving an error correction packet for performing error correction of a data packet for which a reproduction order is determined or an interleaving process for rearranging the data packets in a transmission order different from the reproduction order A receiving unit for receiving a block including:
A reproducing unit for reproducing the data packet;
A pre-processing unit that outputs the data packet received by the receiving unit to the reproducing unit side,
The pre-processing unit outputs the data packet that has been subjected to error correction processing for correcting an error of the data packet by the error correction packet or deinterleaving processing for rearranging the data packet according to the reproduction order. And a second operation mode for outputting the data packet not subjected to the error correction process or the deinterleave process,
The reproduction unit reproduces the data packet output by the preprocessing unit in the second operation mode by still reproduction or slow reproduction until the operation mode is switched from the second operation mode to the first operation mode. A receiving device.   The pre-processing unit operates in the second operation mode before all the new blocks that are the first blocks included in the new streaming content are received, and after all the new blocks are received. The receiving apparatus according to claim 7, wherein the receiving apparatus operates in the first operation mode.   The said pre-processing part performs the switch from the said 2nd operation mode to the said 1st operation mode, when the loss of the said data packet is detected in the said 2nd operation mode. Receiver. An error correction giving unit for giving an error correction packet for performing error correction of the data packet to a data packet in which a reproduction order is determined, and generating a block including the data packet and the error correction packet;
A transmission unit for transmitting the block generated by the error correction giving unit,
The block is composed of a plurality of packet units whose transmission order is determined,
Each of the plurality of packet units is configured by the data packets in which the reproduction order is continuous,
The transmission apparatus according to claim 1, wherein the error correction giving unit generates the error correction packet by using the data packets whose reproduction order is not continuous.

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