JP2009258607A - Reproducing apparatus and receiving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reproducing apparatus, in which the time required from change of a reproducing channel to the start of reproduction is small. <P>SOLUTION: This reproducing apparatus includes: a receiving channel list for registering address information of a reproducing channel and one or two peripheral channels; a receiving means for receiving data of two or more broadcast channels; a plurality of buffer means; a receiving control means for storing data of the broadcast channel received by the receiving means in the buffer means; a determination means for determining the contents of a change when the reproducing channel is changed; and an updating means for updating the receiving channel list, wherein the updating means determines a peripheral channel according to the contents of a change, the address information on the peripheral channel is registered in the receiving channel list, and the receiving control means stores data of the broadcast channel registered in the receiving channel list among the data of the two or more broadcast channels received by the receiving means in the buffers different depending on every broadcast channel. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a playback apparatus, and more particularly to a playback apparatus that plays back a data stream that has been streamed via a network.

  In recent years, with the progress of digitization of broadcast waves and the development of broadband, services that provide streaming distribution of broadcast content in real time to each home via a network have been provided. For such services, for example, unicast technology of an IP (Internet Protocol) network or multicast technology as described in Patent Document 1 below, streaming delivery of broadcast content to a receiving terminal is realized. When streaming broadcast content, it is indispensable for a receiving device that receives the broadcast content to buffer the stream data regardless of whether it is unicast or multicast. Since an IP network is a network that has no guaranteed service quality and is predicated on best effort, it is inevitable that packet loss or arrival delay will occur due to increased load or congestion. As a result, sound interruption and reproduction interruption occur on the receiving terminal side. The next-generation network aims to realize QoS (Quality of Service) technology considering the priority order of packets from a low-reliability best-effort network, but has not yet been realized.

Therefore, in order to avoid problems such as sound interruption, the receiving terminal generally starts playback after buffering the stream data of the broadcast content to some extent. When the buffering size is, for example, one second, in the case of IP unicast, stream data is continuously transmitted, so the time required for buffering is determined according to the communication line speed. For example, when the receiving terminal buffers stream data with a sampling bit rate of 128 kbps via a line with a transfer rate of 10 Mbps, the time required to buffer the stream data for one second of playback is as short as 0.0125 seconds. It takes time. On the other hand, in the case of IP multicast, the server side transmits stream data at a predetermined transfer speed regardless of the communication line speed. For example, when stream data with a sampling bit rate of 128 kbps is transferred at a transfer speed of 128 kbps, playback is performed for 1 second. It takes 1 second to buffer. As described above, in the case of IP multicast, the time required for buffering is large. Therefore, at the start of playback that requires buffering or when the broadcast content is changed (when the broadcast channel is changed), until the playback of the stream data is started. There is a problem that waiting time occurs. In addition, if the buffering size is increased in consideration of the low-reliability network environment, there is a problem that the waiting time increases accordingly, and as a result, the usability is significantly reduced.
Japanese Patent Laying-Open No. 2005-086222

  The present invention has been made in order to solve the above-described conventional problems, and an object of the present invention is to provide a playback apparatus in which the time required from the change of the playback channel to the start of playback is small.

  A playback apparatus according to a preferred embodiment of the present invention includes: a reception channel list for registering address information of a first broadcast channel instructed to be played and address information of one or more second broadcast channels; The receiving means for receiving the data of the broadcast channel, a plurality of buffer means, the reception control means for storing the data of the broadcast channel received by the receiving means in the buffer means, and the first broadcast channel have been changed A determination means for determining the change contents of the first broadcast channel and an update means for updating the reception channel list; the update means selects the second broadcast channel according to the change contents. The address information of the determined second broadcast channel is registered in the reception channel list, and the reception control means receives it by the reception means. Of the data of a plurality of broadcast channels, the data of the broadcast channel whose address information is registered in the reception channel list is stored in a different buffer for each broadcast channel. The address information of the second broadcast channel determined according to the change contents of the first broadcast channel is registered in the reception channel list, and the second broadcast channel is buffered. That is, in accordance with the change contents of the first broadcast channel, a suitable second broadcast channel that may be changed as the first broadcast channel is predicted and buffered in advance. As a result, when the broadcast channel to be reproduced is changed, the reproduction can be started immediately.

  In a preferred embodiment, the reception channel list includes a first area in which address information of the first broadcast channel is registered and a plurality of second areas in which address information of the second broadcast channel is registered. The update means registers the address information of the broadcast channel on the first direction side from the first broadcast channel after the change when the change content is a channel change in the first direction. In the case where the second area is increased and the change content is a channel change in the second direction opposite to the first direction, the broadcast on the second direction side of the first broadcast channel after the change is performed. The second area for registering channel address information is increased.

  Since the broadcast channel to be played is generally changed continuously in the same direction, when the broadcast channel to be played is changed, the broadcast channel in the same direction as the changed direction is changed to the first one. More buffering as 2 broadcast channels. As a result, even if the reproduction channel is further changed in the same direction, it can be reproduced immediately.

  In a preferred embodiment, the reception channel list has a predetermined number of areas to which an index indicating a position in the reception channel list is assigned; and the update means increments the first broadcast channel. The first area is changed to one of the index areas smaller than the central area in the reception channel list, and the index area larger than the first area after the change is changed to the first area. When the address information of the second broadcast channel having a channel number larger than that of one broadcast channel is registered and the change content is a decrement of the first broadcast channel, the first area is designated as the central area. Change to one of the larger index areas, and smaller index than the first area after the change A region, a channel number than channels of the first to register the smaller the address information of the second broadcast channel.

  As a result, even if the number of areas in the reception channel list is limited, more broadcast channels on the same direction as the direction in which the broadcast channel to be reproduced is changed can be registered in the reception channel list as the second broadcast channel. .

  In a preferred embodiment, the second broadcast channel is a broadcast channel around the first broadcast channel.

  By making the second broadcast channel a broadcast channel around the first broadcast channel that is likely to be selected next by the user, the first broadcast channel after the change is immediately started to be played more reliably. can do.

  In a preferred embodiment, the plurality of broadcast channels are categorized, and the change content is a channel change from the first category to the second category, or channels equal to or greater than a predetermined number of broadcast channels. If it is a change, the updating means sets the central area in the reception channel list as the first area.

  Accordingly, for example, even when the category of the playback channel is changed or when the playback channel is greatly changed by a predetermined number of channels, the broadcasting channels around the first broadcasting channel can be buffered in a balanced manner. Therefore, it is possible to prepare for playback of a broadcast channel that may be changed next.

  In a preferred embodiment, it has a playlist in which address information of a plurality of broadcast channels is registered; when the first broadcast channel is selected from the playlist, the second broadcast channel is a playlist. In the vicinity of the first broadcast channel.

  Thus, even when the first broadcast channel is changed based on the playlist, broadcast channels around the first broadcast channel in the playlist can be buffered in advance, so that Even if another broadcast channel is selected, playback can be started immediately.

  In a preferred embodiment, the first broadcast channel after the change does not correspond to any of one or a plurality of second broadcast channels determined according to the first broadcast channel before the change. The reception control means stores the changed data of the first broadcast channel in the buffer, and after storing the changed first broadcast channel data in the buffer means by a predetermined amount, A buffer different from the buffer means in which the data of the first broadcast channel after the change is stored for the data of the one or more second broadcast channels determined according to the first broadcast channel after the change Start storing in the means.

  As a result, the first broadcast channel (playback channel) after the change is registered in one or a plurality of second broadcast channels (reception channel list before the update) determined according to the first broadcast channel before the change. If it does not fall into any of the peripheral channels), the playback channel packet is buffered first by waiting for buffering of the peripheral channel until the playback channel packet is buffered by a predetermined amount. , Playback of the playback channel is started quickly.

  In a preferred embodiment, after the updating means updates the reception channel list, the reception control means performs post-update before starting to store the changed data of the first broadcast channel in the buffer means. Stop receiving the broadcast channel data of the address information whose address information is not registered in the received channel list.

  If buffering of packets of broadcast channels whose addresses are not registered in the updated reception channel list is completed, it is possible to secure reception bands for buffering a plurality of broadcast channels.

  In another aspect of the present invention, a receiving method is provided. In the receiving method, when a first broadcast channel to be reproduced is changed in a reproducing apparatus including a receiving unit that receives data of a plurality of broadcast channels and a plurality of buffer units, the contents of the change of the first broadcast channel are changed. A receiving channel list including the address information of the first broadcast channel and the address information of one or more second broadcast channels, and the receiving means. The step of storing the data of the broadcast channels whose address information is registered in the reception channel list among the data of the plurality of broadcast channels received in the step S1 is stored in a different buffer for each broadcast channel.

  According to the present invention, the address information of the second broadcast channel determined according to the change contents of the first broadcast channel is registered in the reception channel list, and the second broadcast channel is buffered. That is, in accordance with the change contents of the first broadcast channel, a suitable second broadcast channel that may be changed as the first broadcast channel is predicted and buffered in advance. As a result, when the broadcast channel to be reproduced is changed, the reproduction can be started immediately.

  Hereinafter, the reproducing apparatus 2 according to preferred embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. In addition, the same code | symbol is attached | subjected to the same or an equivalent part in a figure, and the description is used.

  First, a streaming distribution system according to an embodiment of the present invention includes a plurality of streaming servers 1, 1, 1,. The streaming servers 1, 1, 1... And the playback apparatus 2 are connected via the network 3 and belong to the same multicast group. The streaming server 1 is managed by, for example, a broadcasting station that manages a music distribution service and is installed in a broadcasting station facility. The streaming server 1 multicast-distributes one or a plurality of broadcast contents (hereinafter referred to as “broadcast channels”) to which channel numbers are assigned to the playback devices 2 belonging to the same multicast group. The channel numbers are divided into categories. For example, channels A01 to A25 are divided into category A for music broadcasting, and channels B01 to B25 are divided into category B for advertising broadcasting. On the other hand, the playback device 2 is installed, for example, in the home of a user who has contracted for the use of a broadcast channel stream distribution service. The playback device 2 can receive a plurality of broadcast channels distributed from a desired streaming server 1 among a plurality of broadcast channels distributed from the streaming servers 1, 1, 1,... Belonging to the same multicast group. .

  The streaming server 1 accumulates content data of a plurality of broadcast channels and encodes the content data to generate a data stream. Then, the streaming server 1 cuts out the data stream for each fixed size to generate packets, and multicasts the generated packets to the playback device 2 with the group address as the destination. The group address is address information that identifies a multicast group. The streaming server 1 can transmit a packet to the playback device 2 belonging to the multicast group by designating this group address as a destination.

  The network 3 includes a router group corresponding to a router-host protocol such as MLDv2 and a router-to-router protocol such as PIM-SM / DM, and reproduces a packet of the streaming server 1 designated by the reproduction device 2 2 is transmitted.

  Next, the reproducing apparatus 2 will be described in more detail with reference to FIG. FIG. 2 is a schematic block diagram showing the playback device 2. The playback device 2 receives a plurality of broadcast channels at the same time, and plays back one broadcast channel. The playback device 2 includes a reception unit 21, a plurality of buffers 22a, 22b, 22c,..., A control unit 23, a playback unit 24, and a user interface 25.

  The receiving unit 21 notifies the group address of the multicast group and the source address of the streaming server 1 to the router group on the network 3, thereby specifying the designated streaming server among the streaming servers 1, 1, 1... Belonging to the same multicast group. 1 receives packets of a plurality of broadcast channels distributed by multicast. The source address is address information for identifying the streaming server 1. The receiving unit 21 notifies a group of routers and source addresses of a plurality of streaming servers 1 to a router group on the network 3 and receives packets of a plurality of broadcast channels distributed by multicast from the plurality of streaming servers 1. Can do. Then, the broadcast channel designated by the control unit 23 described later is output to the buffer 22.

  The buffer 22 temporarily stores the broadcast channel packets received by the receiving unit 21. That is, the packet received by the receiving unit 21 is buffered. The buffer 22 is a predetermined area allocated on a memory (not shown), and is, for example, a FIFO buffer.

  The control unit 23 receives an instruction from a user interface 25 described later, and controls the operation of the entire playback device 2. The control unit 23 includes a memory 231 and executes various processes of the playback device 2 based on an operation program stored in the memory 231. The control unit 23 controls simultaneous reception of a plurality of broadcast channels. Specifically, the control unit 23 buffers a plurality of broadcast channels received by the reception unit 21 in different buffers 22 for each broadcast channel.

  More specifically, the control unit 23 stores the reception channel list in the memory 231 as metadata. In this reception channel list, address information of broadcast channels to be buffered is registered. This address information includes a group address, a source address, and a port number. The port number is an identification number used in UDP (User Datagram Protocol), and here is for identifying a broadcast channel. The control unit 23 can identify which broadcast channel the packet received by the receiving unit 21 is based on this address information.

  When the broadcast channel (reproduction channel) to be reproduced is notified from the user interface 25, the control unit 23 registers the address information of the reproduction channel and the address information of the peripheral channels in the reception channel list (details will be described later). The peripheral channels are broadcast channels adjacent to the playback channel. For example, the peripheral channels of the playback channel A03 are the broadcast channels A01, A02, A04, and A05 adjacent in the channel number. Then, the control unit 23 buffers the broadcast channel packets whose address information is registered in the reception channel list among the broadcast channel packets received by the reception unit 21 in different buffers 22 for each broadcast channel. These processes are performed by the control unit 23 generating and executing a plurality of reception programs. For example, in each reception program, one broadcast channel to be received is designated, and a buffer 22 for buffering packets of the broadcast channel is designated. The designated broadcast channel is one of broadcast channels whose address information is registered in the reception channel list. The control unit 23 executes the reception program and buffers the designated broadcast channel packet in the designated buffer 22 among the broadcast channel packets received by the reception unit 21. Then, the control unit 23 instructs the reproduction unit 24 described later to reproduce the reproduction channel.

  The playback unit 24 reads the packet sequence from the buffer 22 in which packets of the playback channel are buffered, and converts the packet sequence into stream data. Then, the stream data is decoded and reproduced.

  The user interface 25 receives an instruction from the user and transmits the instruction to the control unit 23. For example, the user interface 25 includes an operation key for selecting a reproduction channel and a display for confirming various information such as a channel number and a broadcast name of the reproduction channel. A remote control device such as a remote controller may also be included.

[Receiving channel list]
Next, the reception channel list will be described in detail with reference to FIG. FIG. 3 is a diagram showing a reception channel list. The reception channel list has a plurality of channel areas to which an index S (S = 0, 1, 2,...) Is allocated, and address information of broadcast channels to be buffered is registered in this channel area. The number of channel regions in the reception channel list is determined by setting a parameter called size S in the reception channel list, and is S + 1. For example, when the size S of the reception channel list is set to 4, the reception channel list has five channel regions from index 0 to index 4. In other words, in this case, five pieces of broadcast channel address information to be buffered are registered in the channel list.

Then, a center channel region is set as a reference channel region among the channel regions from index 0 to index S determined by size S. This center channel area is set to the channel area of index C shown in the following equation 1, and the address information of the reproduction channel is registered. The width W1 in the equation 1 is a parameter determined by the size S as shown in the following equation 2. Also, address information of peripheral channels is registered in other channel areas. Hereinafter, a channel region in which peripheral channel address information is registered is defined as a peripheral channel region, a channel region having an index smaller than the index C of the center channel region is a low channel region, and a channel region having an index larger than the index C of the center channel region Is the high channel region. In the reception channel list set in this way, the center channel area is set in the center channel area from index 0 to index S, and the number of channel areas that are low channel areas and the number of channel areas that are high channel areas are the same. is there.
(Equation 1)
C = W1
(Equation 2)
S + 1 = 2 × W1 + 1

  In the low channel area, address information of peripheral channels on the first direction side from the reproduction channel is registered. For example, in the low channel area, address information of peripheral channels smaller than the channel number of the reproduction channel is registered. Specifically, when the reproduction channel is the broadcast channel A05, address information of the broadcast channels A04, A03,... Is registered in order in the low channel area. The broadcast channels A25, A24... Are registered after the broadcast channel A01. In the high channel area, address information of peripheral channels on the second direction side from the reproduction channel is registered. The second direction is opposite to the first direction. For example, address information of peripheral channels larger than the channel number of the reproduction channel is registered in the high channel area. Specifically, when the reproduction channel is the broadcast channel A05, address information of the broadcast channels A06, A07,... Is registered in order in the low channel area. The broadcast channels A01, A02,... Are registered after the broadcast channel A25 in a circulating manner.

  Further, when the playback channel is changed toward the first direction by the user interface 25 described later (or when the playback channel is changed toward the second direction opposite to the first direction), the same operation is performed. It is desirable to buffer many broadcast channels in the changed direction so that even if the playback channel is further changed in the direction, the playback channel can be immediately played back. Here, the change in the first direction means, for example, that the reproduction channel is decremented from the broadcast channel A05 to the broadcast channel A04, and the change in the second direction means that the reproduction channel is broadcast from the broadcast channel A04. Say to be incremented to channel A05.

Therefore, when the reproduction channel is incremented (or decremented), the number of channel regions in the high channel region (or low channel region) of the reception channel list is increased. Specifically, the index C of the channel area set as the center channel area in the reception channel list is reduced (or increased), and the number of high channel areas (or low channel areas) is increased. For example, the index C is set so as to satisfy the condition further including the weighting factor W2 as shown in the following formula 3. The weighting factor W2 is a parameter that is set so that, for example, the condition expressed by the following equation 4 is satisfied when the reproduction channel is incremented and the condition expressed by the following equation 5 is satisfied when the reproduction channel is decremented. is there. Accordingly, the number of low channel areas or the number of high channel areas can be increased by changing the area set as the center channel area in the reception channel list (details will be described later).
(Equation 3)
C = W1-W2
(Equation 4)
W2 ≦ S / 2 −1
(Equation 5)
W2 ≦ −S / 2−1

[Receive control processing]
Next, the operation of the content reproduction apparatus 2 having the above configuration will be described with reference to FIGS. FIG. 4 is a flowchart showing the reception control process of the control unit 23. FIG. 5 is a conceptual diagram showing a reception channel list. The initial state of the reception channel list will be described on the assumption that the size S is 4 and the reception channel list has five channel regions as shown in FIG. Further, the weighting factor W2 is 0, and the channel region of index 2 is set as the center channel region from the above equations 2 and 3.

  When the playback channel is changed by an instruction from the user interface 25, the control unit 23 updates the reception channel list (S101). Although details will be described later, the control unit 23 determines the change contents of the reproduction channel and updates the reception channel list according to the change contents. In step S101, for example, the address information of the broadcast channel A03 is registered in the center channel area of the reception channel list, the address information of channels A01 and A02 is registered in the low channel area, and the address information of channels A04 and A05 is registered in the high channel area. Is registered (FIG. 5).

  Next, the control unit 23 receives a reproduction channel (S102). Specifically, the control unit 23 buffers, in the buffer 22, a playback channel packet in which address information is registered in the center channel region of the reception channel list among a plurality of broadcast channel packets received by the reception unit 21. To do. For example, when the address information of the broadcast channel A03 is registered in the center channel area as described above, the control unit 23 generates and executes a reception program for buffering the broadcast channel A03 in the buffer 22a. Thereby, the packet of the broadcast channel A03 is buffered in the buffer 22a. Then, the control unit 23 instructs the reproduction unit 24 to reproduce the reproduction channel (S103). The reproducing unit 24 reads the packet sequence from the buffer 22a, converts it into stream data, decodes and reproduces the stream data.

  Next, the control unit 23 receives a peripheral channel (S104). Specifically, if there is a peripheral channel whose address information is registered in the reception channel list that is not currently being buffered, the control unit 23 starts buffering the packet of the peripheral channel. Further, the control unit 23 registers the address information of the peripheral channels that have started buffering in the receiving channel list. The receiving channel list is used to determine which broadcast channel is being buffered. Address information of the broadcast channel being buffered is registered and stored in the memory 231.

  For example, as shown in FIG. 5, the address information of the broadcast channels A01 to A05 is registered in the reception channel list, and the packet of the reproduction channel A03 and the packet of the peripheral channel A04 are being buffered in the buffers 22a and 22b. Then, the control unit 23 determines that the broadcast channels A01, A02, and A05 are not currently buffering. Then, the control unit 23 allocates the buffers 22c, 22d, and 22e to the memory area, and generates a plurality of reception programs for storing the packets of the broadcast channels A01, A02, and A05 in the different buffers 22c, 22d, and the buffer 22e, respectively. Run them. Accordingly, the packets of the broadcast channels A01, A02, and A05 are buffered in the buffers 22c, 22d, and 22e for each broadcast channel. The buffered broadcast channel continues to be buffered. When a broadcast channel buffered as a peripheral channel is changed as a playback channel, it is not necessary to buffer again, so that playback can be started immediately. Then, the control unit 23 registers the address information of the broadcast channels A01, A02, and A05 that have started buffering in the receiving channel list.

  Next, if a broadcast channel whose address information is not registered in the reception channel list is buffered, the control unit 23 ends the buffering of the broadcast channel (S105). Specifically, if a broadcast channel whose address information is not registered in the reception channel list is in the receiving channel list, the control unit 23 ends buffering of the broadcast channel. For example, if a broadcast channel A06 whose address information is not registered in the reception channel list is registered in the receiving channel list, a reception program for buffering the broadcast channel A06 is executed. The control unit 23 stops the reception program and erases the buffer 22f in which the packet of the broadcast channel A06 has been buffered.

  Through the reception control process described above, the broadcast channels whose address information is registered in the reception channel list are buffered in different buffers 22 for each broadcast channel.

[Reception channel list update processing]
Next, the above-described reception channel list update process (S101) will be described in detail. FIG. 6 is a flowchart showing the reception channel list update process of the control unit 23.

  First, the control unit 23 obtains the distance L between the reproduction channel instructed to be reproduced from the user interface 25 and the broadcast channel currently being reproduced (S201). For example, the control unit 23 obtains the difference between the channel number of the broadcast channel currently being reproduced and the channel number of the newly designated reproduction channel. Specifically, when the broadcast channel A02 is being reproduced and the broadcast channel A02 is newly designated as the reproduction channel, the control unit 23 sets the distance L to (02-01) = 1. Then, the control unit 23 sets the weight W2 for the reception channel list according to the distance L (S202).

  Specifically, the control unit 23 increases the weight W2 if the distance L obtained in step S201 is positive (S202a). More specifically, the control unit 23 sets the weight W2 to satisfy the above formula 4. For example, if channel A02 is newly selected while channel A01 is currently being played back, the distance L is 1 and positive, so weight W2 is 1 from equation (4). If the distance L is negative, the controller 23 decreases the weight W2 (S202c). More specifically, the control unit 23 sets the weight W2 to satisfy the above formula 5. For example, when the channel A02 is being reproduced and the channel A01 is newly selected, the distance L is -1 and negative, so the weight W2 is -1 from Equation 5. If the broadcast channel category is changed from the category A channel A01 to the group B channel B01, the control unit 23 determines that the distance L is 0 and resets the weight W2 (S202c). Here, the reset means setting the weight W2 to 0, and the index C substantially satisfies the condition of the above formula 1. Further, even when the category of the broadcast channel is not changed, the control unit 23 resets the weight W2 even when the absolute value of the distance L exceeds a predetermined value such as 10, for example.

  Next, the control unit 23 sets a center channel area for the reception channel list and registers address information of the reproduction channel (S203). Specifically, the control unit 23 obtains the index C based on the weight W2 set in step S202 and the above equation 3, and sets the channel area of the index C as the center channel area. Then, the control unit 23 registers the address of the reproduction channel instructed to be reproduced in the center channel area. Next, the control unit 23 registers the peripheral channels in the reception channel list (S204). Specifically, the control unit 23 registers, in descending order, broadcast channels having channel numbers smaller than the playback channel in the low channel area of the reception channel list, and ascending order of broadcast channels having channel numbers larger than the playback channel in the high channel area. Register with.

  The reception channel list update process will be described more specifically below. First, the reception channel list update process when the reproduction channel is incremented will be described in detail with reference to FIG. FIG. 7 is a conceptual diagram showing a reception channel list when the reproduction channel is incremented. Before the reproduction channel is incremented, as shown in FIG. 7 (a), the reception channel list has the size S of 4 and the center channel area is set to the channel area of index 2, and this center channel area is set as a reproduction channel. Assume that the address information of the broadcast channel A03 is registered. Also, address information of broadcast channels A01 and A02 are registered as peripheral channels in the low channel area, and address information of broadcast channels A04 and A05 are registered as peripheral channels in the high channel area.

  Here, when the reproduction channel is incremented to the broadcast channel A11, the control unit 23 obtains the distance L as 8 in step S201. In step S202, the control unit 23 determines that the distance L is positive, and sets the weight W2 to 1 based on the above equation 4 because the size S of the reception channel list is 4 (S203a). As a result, the index C of the center channel region is changed from 2 to 1 from the above equation 3, and the channel region of the index 1 is set as the center channel region (FIG. 7B). At this time, only index 0 is a low channel region, and three regions of indexes 2 to 4 are high channel regions. In step 204, the address of the broadcast channel A11 is registered in the center channel area. In step 205, the address of broadcast channel A10 is registered in the low channel area, and the addresses of broadcast channels A12, A13, and A14 are registered in ascending order in the high channel area. In other words, when the playback channel is incremented, the channel area set as the center channel area is changed to the one with a smaller index, so that a large number of broadcast channels with channel numbers larger than the playback channel are registered in the reception channel list. become. As a result, among the peripheral channels for which buffering is started in step S104 of the reception control process, the number of broadcast channels having a channel number larger than that of the playback channel increases, and even if the playback channel is further incremented, playback is immediately possible.

  Next, the reception channel list update process when the reproduction channel is decremented will be described in detail with reference to FIG. FIG. 8 is a conceptual diagram showing a reception channel list when the reproduction channel is decremented. Before the playback channel is decremented, as shown in FIG. 8A, the reception channel list has a size S of 4 and the center channel region is set to the channel region of index 2, and this center channel region is set as a playback channel. Assume that the address information of the broadcast channel A11 is registered. Also, address information of broadcast channels A09 and A10 are registered as peripheral channels in the low channel area, and address information of broadcast channels A12 and A13 are registered as peripheral channels in the high channel area.

  Here, when the playback channel is decremented to the broadcast channel A04, the control unit 23 obtains the distance L as -7 in step S201. In step S202, the control unit 23 determines that the distance L is negative, and since the size S of the reception channel list is 4, sets the weight W2 to −1 based on the above equation 5 (S203c). As a result, the index C of the center channel region is changed from 2 to 3 from the above formula 3, and the channel region of the index 3 is set as the center channel (FIG. 8B). At this time, the three areas of indexes 0 to 2 are low channel areas, and only index 4 is a high channel area. In step 204, address information of the broadcast channel A04 is registered in the center channel area. In step 205, the address information of the broadcast channels A01, A02, A03 is registered in descending order in the low channel area, and the address information of the broadcast channel A05 is registered in the high channel area. In other words, when the playback channel is decremented, the channel area set as the center channel area is changed to the higher index side, so that many broadcast channels with channel numbers smaller than the playback channel are registered in the reception channel list. become. As a result, among the peripheral channels for which buffering is started in step S104 of the reception control process, the number of broadcast channels having a channel number smaller than that of the reproduction channel increases, and even if the reproduction channel is further decremented, it can be reproduced immediately.

  Next, the reception channel list update processing when the reproduction channel is changed to a broadcast channel of another category will be described in detail with reference to FIG. FIG. 9 is a conceptual diagram showing a reception channel list when the reproduction channel is changed to a broadcast channel of another category. Before the playback channel is changed to a broadcast channel of another category, as shown in FIG. 9 (a), the reception channel list is set to a channel area of size S of 4 and a center channel area of index 2. It is assumed that broadcast channel A03 is registered as a playback channel in the center channel area. Also, address information of broadcast channels A01 and A02 are registered as peripheral channels in the low channel area, and address information of broadcast channels A04 and A05 are registered as peripheral channels in the high channel area.

  Here, when the reproduction channel is changed to the broadcast channel B11 of another category, the control unit 23 obtains the distance L as 0 in step S201, determines that the distance L is 0 in step S202, and sets the weight W2 to 0. Set (S202b). As a result, from the above equation 3, the index C remains 2 and the settings of the center channel region, the low channel region, and the high channel region are not changed (FIG. 9B). In steps S204 and S205, the address information of channel B11 is registered in the center channel area, the address information of broadcast channels B09 and B10 are registered in descending order in the low channel area, and the broadcast channels B12 and B13 are registered in the high channel area. Address information is registered. That is, when the playback channel is changed to a broadcast channel of another category, the center channel area is set as the center channel area in the reception channel list, so the same number of broadcast channels with the channel numbers around the playback channel are set. Will only be registered. As a result, among the peripheral channels for which buffering is started in step S104 of the reception control process, the broadcast channel having a channel number smaller than the reproduction channel and the broadcast channel having a channel number larger than the reproduction channel are buffered with the same balance. To prepare for the next broadcast channel change.

  Next, reception control for simultaneously receiving a plurality of broadcast channels registered in the playlist will be described. The playlist here is a list in which a plurality of broadcast channels frequently viewed by the user, user favorite channels, and the like are registered.

  FIG. 10 shows a play list. The playlist is stored in the memory 231 or the like, and for example, address information of a broadcast channel desired by the user as a favorite channel is registered. In the playlist, a playlist number assigned separately from the channel number is registered corresponding to the address information. In simultaneous reception of favorite channels, reception control processing and reception channel list update processing are executed based on the favorite channel number.

  Hereinafter, a reception control process for simultaneously receiving broadcast channels registered in a playlist will be described, but only points different from the above-described reception control process will be described with reference to FIGS. First, when a user selects a playlist channel that the user desires to play out of broadcast channels (playlist channels) whose address information is registered in the playlist, the playlist channel selected from the user interface 25 to the control unit 23 is selected. Notified as a playback channel. When receiving a playback channel instruction from the user interface 25, the control unit 23 updates the reception channel list with the playback channel as a center channel (S101).

  Next, the reception channel list update process of the control unit 23 when simultaneously receiving the broadcast channels registered in the playlist will be described with reference to FIG. 6 and only the differences from the above update process. First, in step S201, the control unit 23 obtains a distance L between the currently reproduced broadcast channel and the newly designated reproduction channel. Specifically, for example, when playback of the playlist channel 02 is instructed while the playlist channel 03 is being played back, the control unit 23 sets the distance L to (03− 02) = 1. Then, the control unit 23 sets the weight W2 for the reception channel list according to the distance L in the same manner as in Steps S202 and 203 in the above-described reception channel list update processing (S202), and the channel area of the index C Is set as the center channel area, and the address of the reproduction channel is registered in the center channel area (S203). Next, the control unit 23 sets a peripheral channel in the reception channel list (S204).

  The peripheral channel here is a playlist channel having a similar playlist number in the playlist. Specifically, playlist channels smaller than the playlist number of the playlist channel selected as the reproduction channel are registered in descending order in the low channel region. In the high channel area, playlist channels larger than the playlist number of the playlist channel selected as the playback channel are registered in ascending order. For example, when playlist channel 03 is selected as the playback channel, the address of playlist channel 03 is registered in the center channel area of the reception channel list, and the addresses of playlist channels 01 and 02 are registered in the low channel area. The addresses of the playlist channels 04 and 05 are registered in the high channel area. Thereafter, the control unit 23 returns to steps S102 to S105 of the reception control process, and among the plurality of broadcast channels received by the reception unit 21, the broadcast channel whose address is registered in the reception channel list is different for each broadcast channel. To buffer.

  As described above, even when the channel is changed based on the playlist, since the peripheral channels on the playlist are buffered, it is possible to immediately start reproducing the channel.

  Next, the reception control process in another preferred embodiment of the present invention will be described with reference to FIGS. 9, 11 and 12, but only the points different from the above-described reception control process will be described. FIG. 11 is a flowchart showing a reception control process in another preferred embodiment of the present invention. FIG. 12 is a conceptual diagram showing a reception channel list when the reproduction channel is incremented. In the above-described reception control process, by predicting a neighboring channel that may be changed next as a reproduction channel and buffering in advance, reproduction can be started immediately when the reproduction channel is changed. However, depending on the processing capability of the control unit 23, it takes time to process the reception program of the peripheral channel, and it is not possible to allocate sufficient time for the processing of the reception channel reception program. As a result, it may take time until the playback channel is played back. In particular, when the playback channel is changed to a broadcast channel of another category (for example, broadcast channel A03 to broadcast channel B11), or even if it is a broadcast channel in the same category, it is greatly incremented or decremented (for example, the broadcast channel). A03 to broadcast channel A11), the reproduction channel and the peripheral channel are all buffered from scratch, so that it takes time to process the reception program of the peripheral channel, and it takes time to buffer the reproduction channel. .

  Therefore, the control unit 23 determines whether or not the reproduction channel notified from the user interface 25 is a peripheral channel registered in the reception channel list before update. Specifically, the peripheral channel registered in the reception channel list before the update is being received, and the address information thereof is registered in the receiving channel list. Therefore, the address information of the reproduction channel is included in the receiving channel list. Determine if it is registered. If the address information of the reproduction channel notified from the user interface 25 is not registered in the receiving channel list, the packet of the reproduction channel is not buffered. Therefore, the control unit 23 should give the highest priority to buffering of the reproduction channel. And wait for buffering of peripheral channels until a predetermined amount of packets of the playback channel are buffered. If the address information of the playback channel notified from the user interface 25 is registered in the receiving channel, the playback channel packet is already buffered and playback of the playback channel can be started. Start buffering the channel. Hereinafter, the reception control process will be described in detail.

  First, when the reproduction channel is changed by an instruction from the user interface 25, the control unit 23 updates the reception channel list (S101). For example, when the reproduction channel is changed from the broadcast channel A11 to the broadcast channel B11 by an instruction from the user interface 25, the reception channel list before the reproduction channel is changed (before update) is as shown in FIG. In addition, address information of the broadcast channel A11 is registered in the center channel area as a reproduction channel, address information of the broadcast channels A09 and A10 is registered in the low channel area as peripheral channels, and address information of the broadcast channels A12 and A13 is registered in the high channel area. Suppose that Further, the packets of these broadcast channels A09 to A13 whose address information has been registered in the reception channel list before update are buffered in different buffers 22a to 22e, respectively, and the broadcast channels A09 to A13 of the broadcast channels A09 to A13 are included in the receiving channel list. Assume that address information is registered. Further, in the reception channel list updated by the process of step A101 after the reproduction channel is changed to the broadcast channel B11, as shown in FIG. 9B, the address information of the broadcast channel B11 is registered in the center channel area as the reproduction channel. Assume that the address information of broadcast channels B09 and B10 is registered in the low channel area and the address information of broadcast channels B12 and B13 are registered in the high channel area as peripheral channels.

  Next, if a broadcast channel not registered in the updated reception channel list is received, the control unit 23 ends the reception of the broadcast channel (S106). Specifically, the broadcast channels being received are broadcast channels A09 to A13 registered in the receive channel list, whereas the broadcast channels registered in the updated receive channel list are broadcast channels B09. Since it is ~ B13, the control unit 23 ends the reception of the broadcast channels A09 to A13 whose addresses are not registered in the updated reception channel list. This is because if reception of a broadcast channel whose address is not registered in the reception channel list is completed, a reception band for buffering a plurality of broadcast channels can be secured. Then, the control unit 23 receives the reproduction channel (S102), and instructs the reproduction unit 24 to reproduce the reproduction channel (S103).

  Next, the control unit 23 determines whether or not the address information of the reproduction channel notified from the user interface 25 is registered in the receiving channel list (S107). Here, since the playback channel B11 is not registered in the receiving channel list (S107: NO), and the packet of the playback channel B11 is not buffered in the buffer 22a, the control unit 23 gives the highest priority to reception of the playback channel. It is determined that it should be performed, and the reception of the peripheral channels B09, B10, B12 and B13 is waited until a predetermined amount of packets of the reproduction channel B11 are buffered in the buffer 22a (S108). When a predetermined amount of packets of the reproduction channel B11 are buffered in the buffer 22a, the control unit 23 receives the peripheral channels B09, B10, B12, and B13 (S104) and receives the broadcast channels B09 to B13 being received. Is registered in the receiving channel list (S109). As described above, when the playback channel notified from the user interface 25 is not a peripheral channel registered in the reception channel list before update (when the playback channel is not registered in the receiving channel list), the packet of the playback channel is By waiting for buffering of the peripheral channels until a predetermined amount is buffered, the control unit 23 can buffer the packets of the reproduction channel first, and can quickly start reproduction of the reproduction channel.

  In step S107, when the playback channel is registered in the receiving channel list, the playback channel is incremented or decremented to the broadcast channel received as the peripheral channel. For example, as shown in FIG. 12A, the reception channel list before the change of the reproduction channel is registered in the center channel area as the reproduction channel, and the broadcast channel A11 address information is broadcast as the peripheral channel in the low channel area. It is assumed that the address information of the channels A09 and A10 and the address information of the broadcast channels A12 and A13 are registered in the high channel area, and these broadcast channels A09 to A13 are received. Further, address information of these broadcast channels A09 to A13 is registered in the receiving channel list. When the playback channel is changed to the broadcast channel A12 received as a peripheral channel from the broadcast channel A11 by an instruction from the user interface 25, the playback channel is changed to the broadcast channel A12, and the received channel list is changed by the process of step A101. As shown in FIG. 12B, address information of the broadcast channel A12 is registered in the center channel area as a reproduction channel, broadcast channel A11 address information in the low channel area as peripheral channels, and broadcast channels A13 to A15 in the high channel area. Address information is registered.

  In this case, since the reproduction channel A12 is a peripheral channel registered in the reception channel list before update, that is, a broadcast channel registered in the receiving channel list (S107: YES), the control unit 23 Receives the broadcast channels A11 and A13 to A15, which are peripheral channels, assuming that the packet of the reproduction channel A12 has already been buffered in the buffer 22a (S104). Then, the control unit 23 registers the playback channel A12 being received and the peripheral channels A11, A13 to A15 in the channel list being received (S109). Thus, when the reproduction channel notified from the user interface 25 is a peripheral channel registered in the reception channel list before update (when the reproduction channel is registered in the receiving channel list), the control unit 23 It is possible to immediately start playback of the playback channel and start buffering of the peripheral channels.

  As mentioned above, although the example of preferable embodiment of the reproducing | regenerating apparatus based on this invention was demonstrated, embodiment mentioned above is only the illustration for implementing this invention. For example, in this embodiment, the peripheral channel of the reproduction channel is registered in the reception channel list as a channel to be simultaneously received. However, the present invention is not limited to this. For example, a state in which the designated broadcast channel is always received by designating a channel that the user desires to receive simultaneously and always registering address information of the designated broadcast channel in the reception channel list. Therefore, when the user instructs the reproduction of the channel, it can be reproduced immediately.

  The user interface 25 for selecting a broadcast channel that the user desires to reproduce is preferably an operation key such as a jog dial, an up / down key, or an input key capable of inputting a channel number. A jog dial or an up / down key is more preferable. Even more preferred is a jog dial. This is because, when the operation key for channel selection is the jog dial, the peripheral channel can be selected by rotating the jog dial small, and the desired channel can be selected quickly by rotating the jog dial small.

  In the above description, the playlist number includes the playlist number and the address information. However, as shown in FIG. 10, the channel number corresponding to the address information may also be included. This can be used for displaying the channel number of the broadcast channel being viewed on a display or the like and presenting it to the user.

  Furthermore, in the present embodiment, the description has been made based on the channel number, but the present invention is not limited thereto. For example, characters such as alphabets may be assigned such as broadcast channels AA, AB, AC. In this case, the broadcast channel increment and decrement definitions may be set arbitrarily. For example, the change of the broadcast channel in the ascending order (A, B, C...) Of the alphabet is incremented, and the change of the broadcast channel in the descending direction (Z, Y, X...) Is set as the decrement.

  The present invention is preferably used in a playback device that plays back a data stream that is streamed via a network, and can be particularly preferably used in a playback device that plays back a data stream that is distributed by IP multicast.

1 is a schematic configuration diagram illustrating a streaming system according to a preferred embodiment of the present invention. 1 is a block diagram illustrating a playback device according to a preferred embodiment of the present invention. It is a conceptual diagram which shows a receiving channel list. It is a flowchart which shows a reception control process. It is a conceptual diagram which shows a receiving channel list. It is a flowchart which shows the update process of a receiving channel list. It is a conceptual diagram which shows a receiving channel list when a reproduction | regeneration channel is incremented. It is a conceptual diagram which shows a receiving channel list | wrist when a reproduction | regeneration channel is decremented. It is a conceptual diagram which shows a receiving channel list | wrist when a reproduction | regeneration channel is changed into the broadcast channel of another group. It is a table which shows a play list. It is a flowchart which shows a reception control process. It is a conceptual diagram which shows a receiving channel list when a reproduction | regeneration channel is incremented.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Playback apparatus 21 Reception part 22 Buffer 23 Control part 231 Memory 24 Playback part 25 User interface 3 Network

Claims (9)

A reception channel list for registering address information of the first broadcast channel instructed to be reproduced and address information of one or more second broadcast channels;
Receiving means for receiving data of the plurality of broadcast channels;
A plurality of buffer means;
Receiving control means for storing the data of the broadcast channel received by the receiving means in the buffer means;
Determining means for determining the change contents of the first broadcast channel when the first broadcast channel is changed;
Updating means for updating the reception channel list;
The update means determines the second broadcast channel according to the changed content, registers the determined address information of the second broadcast channel in the reception channel list,
The reception control means stores the data of the broadcast channels whose address information is registered in the reception channel list among the data of the plurality of broadcast channels received by the reception means, and stores them in different buffers for each broadcast channel. apparatus. The reception channel list is
A first area in which address information of the first broadcast channel is registered;
A plurality of second areas in which address information of the second broadcast channel is registered;
The updating means
If the change is a channel change in the first direction, the second area for registering the address information of the broadcast channel on the first direction side than the first broadcast channel after the change is increased,
When the change content is a channel change in the second direction opposite to the first direction, the address information of the broadcast channel on the second direction side of the first broadcast channel after the change is registered. The playback apparatus according to claim 1, wherein the area of 2 is increased. The reception channel list is
A predetermined number of areas to which indices indicating positions in the reception channel list are assigned;
The updating means
When the change content is an increment of the first broadcast channel, the first area is changed to one of the index areas smaller than the central area in the reception channel list, and the first area after the change is changed. The address information of the second broadcast channel having the channel number larger than that of the first broadcast channel is registered in the index area larger than
When the change content is a decrement of the first broadcast channel, the first area is changed to one of the index areas larger than the central area, and the changed first area is changed. The reproducing apparatus according to claim 2, wherein address information of the second broadcast channel having a channel number smaller than that of the first broadcast channel is registered in a small index area.   The playback device according to claim 1, wherein the second broadcast channel is a broadcast channel around the first broadcast channel. The plurality of broadcast channels are categorized;
When the change content is a channel change from the first category to the second category, or a channel change that is equal to or greater than the predetermined number of broadcast channels,
5. The playback apparatus according to claim 4, wherein the updating unit sets a central area in the reception channel list as the first area. Having a playlist in which address information of a plurality of broadcast channels is registered;
When the first broadcast channel is selected from the playlist,
The playback device according to claim 1, wherein the second broadcast channel is a broadcast channel around the first broadcast channel in a playlist. When the first broadcast channel after the change does not correspond to any of one or a plurality of second broadcast channels determined according to the first broadcast channel before the change,
The reception control means is
Storing the changed data of the first broadcast channel in the buffer;
One or more second broadcast channels determined according to the changed first broadcast channel after storing a predetermined amount of data of the changed first broadcast channel in the buffer means 7. The reproduction apparatus according to claim 1, wherein the data is started to be stored in a buffer means different from the buffer means in which the data of the first broadcast channel after the change is stored. After the updating means updates the reception channel list,
Before the reception control means starts storing the changed data of the first broadcast channel in the buffer means, the data of the broadcast channel of the address information whose address information is not registered in the updated reception channel list The playback device according to any one of 1 to 7 above, wherein reception of the video is stopped. Receiving means for receiving data of a plurality of broadcast channels and a plurality of buffer means for registering address information of a first broadcast channel to be reproduced and address information of one or more second broadcast channels In a playback device having a reception channel list,
Determining the change contents of the first broadcast channel when the first broadcast channel is changed;
Determining the second broadcast channel according to the contents of the change, and registering the address information of the determined second broadcast channel in the reception channel list;
A receiving method comprising a step of storing data of broadcast channels whose address information is registered in the reception channel list among data of a plurality of broadcast channels received by the receiving means in different buffers for each broadcast channel.

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