JP2014060470A - Broadcast receiver, reproducing method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a broadcast receiver for achieving hierarchy switching reproduction without video disturbance and scene interruption and to provide a reproducing method and a program.SOLUTION: A broadcast receiver reads recorded weak hierarchy and strong hierarchy streams (31 and 32) during reproduction, refers to recorded position identification information (33) and reception quality information (34) and selects as a selection stream one of the weak hierarchy stream (31) and the strong hierarchy stream (32). If an I frame which can be synchronized with an I frame just before deterioration (f25) in the weak hierarchy stream (31) is not present in the strong hierarchy stream (32) while the weak hierarchy stream (31) is being selected, a switching I frame (f20) before the I frame just before deterioration (f25) of the weak hierarchy stream (31) is specified, and the selection stream is switched from the weak hierarchy stream (31) to the strong hierarchy stream (32) at timing of the switching I frame (f20).

Description

  The present invention relates to a broadcast receiving apparatus, a playback method, and a program for switching streams based on reception quality information.

  In digital terrestrial broadcasting, a broadcast wave including a weak layer stream that is a stream (program / content) transmitted in a weak layer and a strong layer stream that is a stream transmitted in a strong layer is received, and the weak layer stream and the strong layer stream are received. A technology that records a layered stream and a radio wave reception status representing a radio wave state when a broadcast wave is received, and switches from one of a weak layer stream and a strong layer stream to the other by referring to the radio wave reception status during playback. It has been known.

  In the technique described in Patent Document 1, when broadcast waves are received, the weak layer stream and the strong layer stream, the position information indicating the positions of a plurality of I frames of these streams, and the radio wave reception status are also combined. The reception quality information indicating the reception quality is recorded, and at the time of reproduction, the reception quality information and the position information are referred to and one of the weak layer stream and the strong layer stream is switched to the other.

Japanese Patent No. 4352976

  However, in digital terrestrial broadcasting, the encoding method differs depending on the bit rate that can be transmitted by the broadcast wave between the weak layer stream and the strong layer stream. For this reason, as shown in FIG. 9, the interval between I frames required for reproduction is also different. The weak hierarchical stream with a high bit rate is encoded with a high video frame rate and a short I-frame interval. On the other hand, in a strong hierarchical stream with a low bit rate, the I-frame interval is long because the video frame rate is low and encoding with high encoding efficiency is employed. For this reason, as shown in FIG. 10, the number of I frames (f10, f15, f20, f25, f30, f35,...) Of the weak layer stream is the number of I frames (f10, f20, f30,...) Of the strong layer stream. In the strong layer stream, there is a time when there is no I frame (f15, f25, f35,...) That can be scene-synchronized with the weak layer stream.

  In addition, the same program is broadcast in the form of simulcast on the weak layer stream and the strong layer stream. However, due to the difference in the encoding method described above, even in the same scene (identified by an I frame) in the weak layer stream and the strong layer stream, the strong layer stream has a predetermined time Δtab ( Generally, transmission is delayed by about 3 seconds).

  In this way, due to the difference in encoding method, as in Patent Document 1, when switching from one of the weak layer stream and the strong layer stream to the other only by referring to the reception quality information and the position information at the time of reproduction, Smooth playback of content cannot be realized because the video is disturbed or the scene is interrupted (a little jumps or goes back a little).

  The present invention has been made in view of the above points, and an object of the present invention is to provide a broadcast receiving apparatus, a reproducing method, and a program that enable hierarchical switching reproduction without image disturbance and scene interruption.

  The broadcast receiving apparatus of the present invention includes a broadcast receiving unit that receives a broadcast wave including a weak layer stream that is a stream transmitted in a weak layer and a strong layer stream that is a stream transmitted in a strong layer, and the weak layer stream And position identification information indicating the strong layer streams, positions of a plurality of I frames of these streams and an identifier for synchronizing the I frames, reception quality information indicating reception quality when the broadcast wave is received, Recorded in the broadcast recording unit, a reproduction control unit that reads the weak layer stream and the strong layer stream recorded in the broadcast recording unit during reproduction, the position identification information recorded in the broadcast recording unit, and the With reference to the reception quality information, one of the weak layer stream and the strong layer stream read by the reproduction control unit is selected and stored. A reproduction quality analysis unit that selects a frame as a selected stream, and the reproduction quality analysis unit receives, among the plurality of I frames of the weak layer stream, when the weak layer stream is selected as the selected stream. When an I frame that is synchronized with an I frame immediately before deterioration, which is an I frame immediately before quality deterioration, does not exist in the strong layer stream, an I frame before the I frame immediately before the deterioration of the weak layer stream is used as a switching I frame. The selected stream is switched from the weak layer stream to the strong layer stream at the timing of the switching I frame.

  The playback method using the broadcast receiving apparatus of the present invention includes receiving a broadcast wave including a weak layer stream that is a stream transmitted in a weak layer and a strong layer stream that is a stream transmitted in a strong layer, Position identification information indicating the weak layer stream and the strong layer stream, the positions of a plurality of I frames of these streams and an identifier for synchronizing the I frames, and reception indicating the reception quality when the broadcast wave is received Recording quality information in a broadcast recording unit, reading out the weak layer stream and the strong layer stream recorded in the broadcast recording unit during reproduction, and the position identification information recorded in the broadcast recording unit And referring to the reception quality information, one of the weak layer stream and the strong layer stream is selected as a selected stream. And when the weak layer stream is selected as the selected stream, it synchronizes with the I frame immediately before deterioration, which is the I frame immediately before the reception quality of the plurality of I frames of the weak layer stream deteriorates. If an I frame does not exist in the strong layer stream, the I frame before the I frame immediately before the deterioration of the weak layer stream is specified as a switching I frame, and the selected stream is detected at the timing of the switching I frame. Switching from a hierarchical stream to the strong hierarchical stream.

  The program of the present invention causes the broadcast receiving apparatus to execute each step of the reproduction method.

  According to the present invention, it is possible to perform hierarchical switching reproduction without image disturbance and scene interruption.

It is a schematic block diagram which shows the structure of the broadcast receiver which concerns on embodiment of this invention. It is a figure for demonstrating the information recorded on the broadcast recording part of the broadcast receiver which concerns on embodiment of this invention, and explaining the 1st reproduction | regeneration method. It is a figure for demonstrating the 2nd reproducing method which shows the information recorded on the broadcast recording part of the broadcast receiver which concerns on embodiment of this invention. In FIG. 3, it is a figure for demonstrating the application example of the 2nd reproduction | regeneration method. It is a figure for demonstrating the information recorded on the broadcast recording part of the broadcast receiver which concerns on embodiment of this invention, and explaining the 3rd reproduction | regeneration method. It is a figure for demonstrating the information recorded on the broadcast recording part of the broadcast receiver which concerns on embodiment of this invention, and explaining the 4th reproducing method. FIG. 6 is a diagram for explaining an application example of the fourth reproduction method. It is a flowchart which shows operation | movement (reproduction | regeneration method) of the broadcast receiver which concerns on embodiment of this invention. It is a figure which shows the weak layer stream and strong layer stream transmitted with a broadcast wave. It is a figure which shows the position of the I frame of the weak layer stream and strong layer stream transmitted with a broadcast wave.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. A broadcast receiving apparatus according to an embodiment of the present invention is applied to a mobile phone, a smartphone, a car navigation system, and the like.

  FIG. 1 is a schematic block diagram showing a configuration of a broadcast receiving apparatus according to an embodiment of the present invention. The broadcast receiving apparatus according to the embodiment of the present invention includes a broadcast receiving unit 21, a broadcast output unit 22, a main control unit 2, an information storage unit 7, an input unit 8, an earphone output unit 11, and a Bluetooth output unit. 12, a playback control unit 13, a recording control unit 14, a broadcast recording unit 15, and a playback quality analysis unit 16.

  The main control unit 2 includes a broadcast receiving unit 21, a broadcast output unit 22, an information storage unit 7, an input unit 8, an earphone output unit 11, a Bluetooth output unit 12, a playback control unit 13, a recording control unit 14, a broadcast recording unit 15, The reproduction quality analysis unit 16 is controlled. The main control unit 2 is composed of, for example, a CPU (Central Processing Unit).

  The broadcast receiving unit 21 includes an antenna 6 and a tuner unit 1. The broadcast output unit 22 includes a separation unit 3, a video decoding unit 4, an audio decoding unit 5, a display unit 9, and a speaker 10.

  The antenna 6 is an antenna that receives digital broadcasting such as multimedia broadcasting. The tuner unit 1 selects the frequency of the broadcasting station designated by the user from the digital broadcast received by the antenna 6, and separates the TS (Transport Stream) of the digital broadcast broadcast at that frequency, or the recording control unit 14 is a tuner that outputs the data to 14. The input unit 8 is an input device that accepts information input operations from the user, such as buttons, a touch panel, and a keyboard.

  The display unit 9 is a display device such as a liquid crystal display that displays digital broadcast video, data broadcast data, information provided to the user, and the like. The speaker 10 is a speaker that outputs digital broadcast sound and the like. The earphone output unit 11 is a processing unit that outputs digital broadcast sound or the like via an earphone jack included in the earphone output unit 11. The Bluetooth output unit 12 is a processing unit that outputs a digital broadcast sound or the like to another device through Bluetooth communication.

  The broadcast recording unit 15 and the information storage unit 7 are storage devices such as a nonvolatile memory and a hard disk device. The broadcast recording unit 15 records a digital broadcast TS. The information storage unit 7 is information obtained by receiving digital broadcasting, such as guidance information (for example, EPG or ECG; hereinafter referred to as stream guidance information) of a stream (program or content) to be broadcast, Information set by the user via the input unit 8, connected OFDM segment information, and the like are recorded. Here, the concatenated OFDM segment information is information on a segment used for broadcasting the stream guide information among the segments included in the concatenated OFDM segment.

  The playback quality analysis unit 16 selects which level of content to play based on the information recorded together with the stream in the broadcast recording unit 15 when the playback control unit 13 reads the stream from the broadcast recording unit 15 during playback. And output to the broadcast output unit 22. Information recorded in the broadcast recording unit 15 will be described.

  First, the broadcast receiving unit 21 receives a broadcast wave to be simulcast. The broadcast wave includes a weak layer stream that is a stream transmitted in the weak layer and a strong layer stream that is a stream transmitted in the strong layer. As shown in FIGS. 2 to 7, the recording control unit 14 broadcasts the weak layer stream and the strong layer stream as the weak layer stream 31 and the strong layer stream 32 at the time of recording during viewing or recording by reservation, respectively. Records in the recording unit 15.

  Here, due to the difference in the encoding method described above, the number of I frames (f10, f15, f20, f25, f30, f35,...) Of the weak layer stream 31 is the number of I frames (f10, f20,. More than f30,..., the strong layer stream 32 has a time when there is no I frame (f15, f25, f35,...) that can be scene-synchronized with the weak layer stream 31. Further, the strong layer stream 32 is transmitted with a delay of a predetermined time Δtab compared to the weak layer stream 31.

  Further, the recording control unit 14 records the position identification information 33 and the reception quality information 34 together with the weak layer stream 31 and the strong layer stream 32 in the broadcast recording unit 15.

  The position identification information 33 includes the positions of a plurality of I frames of the weak layer stream 31 and the strong layer stream 32 and an identifier for synchronizing the scene (I frame). Examples of the identifier include a counter value of a PCR packet.

  The reception quality information 34 includes a radio wave reception status and reception quality when the broadcast receiving unit 21 receives a broadcast wave. Examples of the reception quality information 34 include a carrier-to-noise ratio (CN ratio), a bit error rate (BER), a packet error rate (PER), and a signal reception strength (RSSI). For example, when the value of the CN ratio exceeds the set value of the CN ratio, the reception quality is good. When the values of BER and PER do not exceed the set values of BER and PER, respectively, the reception quality is good. When the RSSI value is within the setting range, the reception quality is good.

  FIG. 8 is a flowchart showing the operation (reproduction method) of the broadcast receiving apparatus according to the embodiment of the present invention. Here, each reproduction method will be described with an example.

(First playback method)
In the first reproduction method, when the weak layer stream 31 is being reproduced, an I frame that can be synchronized with the I frame immediately before the reception quality of the plurality of I frames of the weak layer stream 31 deteriorates becomes the strong layer stream 32. The case where it exists is demonstrated using FIG. 2 and FIG.

  The reproduction control unit 13 reads the weak layer stream 31 and the strong layer stream 32 recorded in the broadcast recording unit 15 during reproduction. The reproduction quality analysis unit 16 refers to the position identification information 33 and the reception quality information 34 recorded in the broadcast recording unit 15, and either one of the weak layer stream 31 and the strong layer stream 32 read by the reproduction control unit 13. As the selection stream. Here, the reproduction quality analysis unit 16 selects the weak layer stream 31 as the selected stream in a time zone in which the reception quality of the weak layer stream 31 is good (step S1-Yes).

  In this case, the broadcast output unit 22 makes the weak layer stream 31 at the reproduction time tα1 delayed by the set time Δtα longer than the predetermined time Δtab with respect to the read time tα2 at which the weak layer stream 31 is read by the reproduction control unit 13. Is output (step S2). Here, it is assumed that the read time tα2 is a time between times t6 and t7, and the reproduction time tα1 is a time between times t2 and t3.

  For example, the reproduction quality analysis unit 16 uses the I frame immediately before the deterioration that is the I frame immediately before the time ta (time between the time t4 and the time t5) when the reception quality of the plurality of I frames of the weak layer stream 31 deteriorates. f20 (I frame f20 at time t4) is detected (steps S3-Yes, S4).

  Here, when an I frame that can be scene-synchronized with the I frame f20 immediately before the deterioration of the weak layer stream 31 exists in the strong layer stream 32 at time t6, the reproduction quality analysis unit 16 changes the I frame f20 immediately before the deterioration to the switching I frame. (Step S5-Yes). The reproduction quality analysis unit 16 switches the selected stream from the weak layer stream 31 at time t4 to the strong layer stream 32 at time t6 at the timing of the switching I frame f20 (step S9).

(Second playback method)
In the second reproduction method, the time during which the reception quality deteriorates is different from that in the first reproduction method. In the second reproduction method, when the weak layer stream 31 is being reproduced, an I frame that can be synchronized with the I frame immediately before the reception quality of the plurality of I frames of the weak layer stream 31 deteriorates becomes the strong layer stream 32. The case where it does not exist is demonstrated using FIG. 3 and FIG. In the second reproduction method, even if there is no I frame that can be synchronized in the strong layer stream 32, it is possible to perform layer switching reproduction without video disturbance and scene interruption.

  The reproduction control unit 13 reads the weak layer stream 31 and the strong layer stream 32 recorded in the broadcast recording unit 15 during reproduction. The reproduction quality analysis unit 16 refers to the position identification information 33 and the reception quality information 34 recorded in the broadcast recording unit 15, and is read by the reproduction control unit 13 in a time zone in which the reception quality of the weak layer stream 31 is good. The weak layer stream 31 is selected as the selected stream from the weak layer stream 31 and the strong layer stream 32 (step S1-Yes).

  In this case, the broadcast output unit 22 reproduces the reproduction time tα1 delayed by the set time Δtα with respect to the read time tα2 (the time between the times t6 and t7) when the reproduction control unit 13 reads the weak hierarchical stream 31. The weak hierarchical stream 31 is output (time between time t2 and t3) (step S2).

  For example, the reproduction quality analysis unit 16 uses the I frame immediately before the deterioration that is the I frame immediately before the time ta (time between the time t6 and the time t7) when the reception quality of the plurality of I frames of the weak layer stream 31 deteriorates. f25 (I frame f25 at time t5) is detected (steps S3-Yes, S4).

  Here, when there is no I frame that can be scene-synchronized with the I frame f25 immediately before the deterioration of the weak layer stream 31 in the strong layer stream 32 (step S5-No), the reproduction quality analysis unit 16 The I frame f20 before the frame f25 is specified as the switching I frame, and it waits until time t4 indicating the position of the I frame f20 of the weak layer stream 31 (steps S6-No, S7). In this case, the reproduction quality analysis unit 16 switches the selected stream from the weak layer stream 31 at time t4 to the strong layer stream 32 at time t6 at the timing of the switching I frame f20 (step S9).

(Application example of the second reproduction method)
The application example of the second reproduction method is different from the second reproduction method in that an intermediate frame described later is generated in the strong layer stream 32. An application example of the second reproduction method will be described with reference to FIGS. Even in this case, it is possible to perform hierarchical switching reproduction without image disturbance and scene interruption.

  After step S4, when there is no I frame that can be scene-synchronized with the I frame f25 immediately before the deterioration of the weak layer stream 31 in the strong layer stream 32 (step S5-No), the reproduction quality analysis unit 16 Of I frames between the I frame f20 and the I frame f30 corresponding to the I frames before and after the I frame f25 immediately before the deterioration of the weak layer stream 31 can be synchronized with the I frame f25 immediately before the deterioration of the weak layer stream 31 A frame f25 ′ is generated (step S6-Yes).

  The reproduction quality analysis unit 16 specifies the I frame f25 immediately before the deterioration of the weak layer stream 31 as the switching I frame, and waits until time t5 indicating the position of the I frame f25 immediately before the deterioration of the weak layer stream 31 (step S8). In this case, the reproduction quality analysis unit 16 switches the selected stream from the weak layer stream 31 at time t5 to the strong layer stream 32 at time tc at the timing of the switching I frame f25 (step S9).

(Third playback method)
In the third reproduction method, when the strong layer stream 32 is being reproduced, the I layer that can be synchronized with the I frame immediately after the reception quality of the weak layer stream 31 is improved is present in the strong layer stream 32. 5 and FIG.

  The reproduction control unit 13 reads the weak layer stream 31 and the strong layer stream 32 recorded in the broadcast recording unit 15 during reproduction. The reproduction quality analysis unit 16 refers to the position identification information 33 and the reception quality information 34 recorded in the broadcast recording unit 15, and either one of the weak layer stream 31 and the strong layer stream 32 read by the reproduction control unit 13. As the selection stream. Here, the reproduction quality analysis unit 16 selects the strong layer stream 32 as the selected stream in the time zone in which the reception quality of the weak layer stream 31 deteriorates (step S1-No).

  In this case, the broadcast output unit 22 has the strong layer stream 32 at the reproduction time tβ1 delayed by the set time Δtβ longer than the predetermined time Δtab with respect to the read time tβ2 at which the reproduction control unit 13 has read the strong layer stream 32. Is output (step S10). Here, it is assumed that the read time tβ2 is a time between times t8 and t9, and the reproduction time tβ1 is a time between times t4 and t5.

  For example, the reproduction quality analysis unit 16 uses the I frame immediately after the improvement, which is the I frame immediately after the time ta (time between the time t5 and the time t6) when the reception quality is improved among the plurality of I frames of the weak layer stream 31. f30 (I frame f30 at time t7) is detected (step S11-Yes, S12).

  If an I frame that can be scene-synchronized with the I frame f30 immediately after improvement of the weak layer stream 31 is present in the strong layer stream 32 at time t9, the playback quality analysis unit 16 changes the I frame f30 immediately after improvement to the switching I frame. (Step S13-Yes). The reproduction quality analysis unit 16 switches the selected stream from the strong layer stream 32 at time t9 to the weak layer stream 31 at time t7 at the timing of the switching I frame f30 (step S17).

(Fourth playback method)
In the fourth reproduction method, the time during which the reception quality deteriorates is different from that in the third reproduction method. In the fourth reproduction method, when the strong layer stream 32 is being reproduced, the strong layer stream 32 has no I frame that can be synchronized with the I frame immediately after the reception quality of the weak layer stream 31 is improved. 6 and FIG. In the fourth reproduction method, even when there is no I frame that can be synchronized in the strong layer stream 32, it is possible to perform layer switching reproduction without image distortion and scene interruption.

  The reproduction control unit 13 reads the weak layer stream 31 and the strong layer stream 32 recorded in the broadcast recording unit 15 during reproduction. The reproduction quality analysis unit 16 refers to the position identification information 33 and the reception quality information 34 recorded in the broadcast recording unit 15, and is read out by the reproduction control unit 13 in a time zone in which the reception quality of the weak layer stream 31 is deteriorated. The strong layer stream 32 is selected as the selected stream from the weak layer stream 31 and the strong layer stream 32 (step S1-No).

  In this case, the broadcast output unit 22 reproduces the reproduction time tβ1 delayed by the set time Δtβ with respect to the read time tβ2 (the time between the times t8 and t9) when the reproduction control unit 13 reads the weak hierarchical stream 31. The strong layer stream 32 is output (time between time t4 and t5) (step S2).

  For example, the reproduction quality analysis unit 16 uses the I frame immediately after the improvement, which is the I frame immediately after the time ta (time between the time t4 and the time t5) when the reception quality is improved among the plurality of I frames of the weak layer stream 31. f25 (I frame f25 at time t5) is detected (step S11-Yes, S12).

  Here, when there is no I frame in the strong layer stream 32 that can be scene-synchronized with the I frame f25 immediately after the improvement of the weak layer stream 31 (step S13-No). The reproduction quality analysis unit 16 specifies the I frame f30 immediately after the improvement of the weak frame stream 31 after the I frame f25 as a switching I frame, and waits until time t9 indicating the position of the I frame f30 of the strong layer stream 32 ( Step S14-No, S15). In this case, the reproduction quality analysis unit 16 switches the selected stream from the strong layer stream 32 at time t9 to the weak layer stream 31 at time t7 at the timing of the switching I frame f30 (step S17).

(Application example of the fourth reproduction method)
The application example of the fourth reproduction method is different from the fourth reproduction method in that an intermediate frame described later is generated in the strong layer stream 32. An application example of the fourth reproduction method will be described with reference to FIGS. Even in this case, it is possible to perform hierarchical switching reproduction without image disturbance and scene interruption.

  After step S12, when there is no I frame that can be scene-synchronized with the I frame f25 immediately after the improvement of the weak layer stream 31 in the strong layer stream 32 (No in step S13), the reproduction quality analysis unit 16 Of the I frames, a scene synchronization can be made between the I frame f20 and the I frame f30 corresponding to the I frames immediately before and after the I frame f25 immediately after the improvement of the weak layer stream 31, and the I frame f25 immediately after the improvement of the weak layer stream 31. The intermediate frame f25 ′ is generated (step S14—Yes).

  The reproduction quality analysis unit 16 identifies the I frame f25 immediately after improvement of the weak layer stream 31 as a switching I frame, and a time tc indicating the position of the intermediate frame f25 ′ of the strong layer stream 32 synchronized with the I frame f25 immediately after improvement. (Step S8). In this case, the reproduction quality analysis unit 16 switches the selected stream from the strong layer stream 32 at time tc to the weak layer stream 31 at time t5 at the timing of the switching I frame f25 (step S17).

  As described above, in the broadcast receiving apparatus according to the embodiment of the present invention, broadcast waves including the weak layer stream 31 that is a stream transmitted in the weak layer and the strong layer stream 32 that is a stream transmitted in the strong layer are transmitted. Receiving broadcast receiving unit 21, weak layer stream 31 and strong layer stream 32, position information 33 indicating the position of each of the plurality of I frames of these streams 31 and 32, and reception quality when a broadcast wave is received The broadcast recording unit 15 in which the reception quality information 34 is recorded, the reproduction control unit 13 that reads the weak layer stream 31 and the strong layer stream 32 recorded in the broadcast recording unit 15 during reproduction, and the broadcast recording unit 15 are recorded. Referring to the position information 33 and the reception quality information 34, the weak layer stream 31 and the strong layer stream read by the reproduction control unit 13 32 and the reproduction quality analyzing unit 16 for selecting one as the selection stream and is provided with a. In the strong layer stream 32, there may be no I frame that can be synchronized with the I frame f25 immediately before deterioration, which is the I frame immediately before the reception quality of the plurality of I frames of the weak layer stream 31 deteriorates. In this case, even if the weak layer stream 31 is switched to the strong layer stream 32, the video is disturbed or the scene is interrupted (a little jumps or a little backwards), so that smooth content reproduction cannot be realized. Therefore, in the above-described second reproduction method (FIG. 3), the reproduction quality analysis unit 16 can synchronize with the I frame f25 immediately before the deterioration of the weak layer stream 31 when the weak layer stream 31 is selected as the selected stream. When the I frame does not exist in the strong layer stream 32, the I frame f20 before the I frame f25 immediately before the deterioration of the weak layer stream 31 is specified as the switching I frame, and the selected stream is weakly layered at the timing of the switching I frame f20. The stream 31 is switched to the strong hierarchy stream 32. As described above, according to the broadcast receiving apparatus according to the embodiment of the present invention, the detection of the stream reproduction position for each layer, the detection of the position of the I frame before and after the stream reading position, and the scene synchronization between the layers based on the I frame. By performing the above, it becomes possible to perform hierarchical switching playback without image disturbance and scene interruption.

  In the broadcast receiving apparatus according to the embodiment of the present invention, in the application example (FIG. 4) of the second reproduction method described above, the reproduction quality analysis unit 16 selects the weak hierarchical stream 31 as the selected stream. In addition, when there is no I frame synchronized with the I frame f25 immediately before the deterioration of the weak layer stream 31 in the strong layer stream 32, the I frame f25 immediately before the deterioration of the weak layer stream 31 among the plurality of I frames of the strong layer stream 32. An intermediate frame f25 ′ that can be synchronized with the I frame f25 immediately before the deterioration of the weak layer stream 31 is generated between the frames f20 and f30 corresponding to the preceding and subsequent I frames, and the I frame f25 immediately before the deterioration of the weak layer stream 31 is generated. Specified as a switching I frame, the selected stream is weak at the timing of switching I frame f20. Switching from stream 31 to the strength layer stream 32. As described above, in the broadcast receiving apparatus according to the embodiment of the present invention, by generating the intermediate frame f25 ′ that can be synchronized with the I frame f25 immediately before the deterioration of the weak layer stream 31, the user deteriorates the reception quality of the weak layer stream 31. It is possible to view with the weak hierarchical stream 31 until immediately before.

  In the broadcast receiving apparatus according to the embodiment of the present invention, the strong layer stream 32 is synchronized with the immediately improved I frame f25, which is the I frame immediately after the reception quality of the plurality of I frames of the weak layer stream 31 is improved. There may be no I frame that can be generated in the strong layer stream 32. In this case, even if the strong layer stream 32 is switched to the weak layer stream 31, the video is disturbed or the scene is interrupted (a little jumps or a little backwards), so that smooth content reproduction cannot be realized. Therefore, in the above-described fourth reproduction method (FIG. 6) or its application example (FIG. 7), the reproduction quality analysis unit 16 selects the strong layer stream 31 when the strong layer stream 32 is selected as the selected stream. When there is no I frame that can be synchronized with the I frame f25 immediately after the improvement in the strong layer stream 32, the I frame f25 immediately after the improvement of the weak layer stream 31 or the I frame f30 thereafter is specified as the switching I frame, and the selected stream is switched. The strong layer stream 32 is switched to the weak layer stream 31 at the timing of the I frame. As described above, according to the broadcast receiving apparatus according to the embodiment of the present invention, the detection of the stream reproduction position for each layer, the detection of the position of the I frame before and after the stream reading position, and the scene synchronization between the layers based on the I frame. By performing the above, it becomes possible to perform hierarchical switching playback without image disturbance and scene interruption.

  In the broadcast receiving apparatus according to the embodiment of the present invention, the strong layer stream 32 is transmitted in the strong layer with a delay of the predetermined time Δtab from the weak layer stream 31. Here, in the broadcast receiving apparatus according to the embodiment of the present invention, the set time Δtα (FIGS. 2 to 4) or Δtβ that is longer than the predetermined time Δtab with respect to the time when the selected stream is read by the reproduction control unit 13. It further includes a broadcast output unit 22 that outputs the selected stream with a delay of (FIGS. 5 to 7). Therefore, in the broadcast receiving apparatus according to the embodiment of the present invention, the reproduction quality analysis unit 16 detects the stream reproduction position for each layer and reads the stream while the reproduction control unit 13 prefetches the stream. It is possible to detect the positions of previous and subsequent I frames and to synchronize scenes between hierarchies using I frames.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the embodiment, and the design and the like within the scope of the present invention are within the scope of the claims. included. The present invention can be modified in various ways within the scope of the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention. It is. Moreover, it is the element described in the said embodiment, and the structure which substituted the element which has the same effect is also contained.

  A computer program (hereinafter referred to as a program) that operates in a broadcast receiving apparatus according to an embodiment of the present invention is a program that controls a CPU or the like (a computer is caused to function) so as to realize the functions of the above-described embodiment according to the present invention. Program). Information handled by these devices is temporarily accumulated in the RAM in terms of processing, then stored in various ROMs and HDDs, read out by the CPU, and corrected and written as necessary. As a recording medium for storing the program, a semiconductor medium (for example, ROM, nonvolatile memory card, etc.), an optical storage medium (for example, DVD, MO, MD, CD, BD, etc.), a magnetic recording medium (for example, magnetic tape, Any of a flexible disk etc. may be sufficient. Further, by executing the loaded program, not only the functions of the above-described embodiment are realized, but also by co-processing with the operating system or other application programs based on the instructions of the program, The functions of the invention may be realized.

  In the case of distribution in the market, the program can be stored and distributed in a portable recording medium, or transferred to a server computer connected via a network such as the Internet. In this case, the recording apparatus of the server computer is also included in the present invention. Further, a part or all of the transmitting station apparatus and the receiving station apparatus in the above-described embodiments may be individually converted into a processor, or a part or all of them may be integrated into a processor. Further, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. Further, when an integrated circuit technology that replaces LSI is realized by the advancement of semiconductor technology, an integrated circuit according to the technology can be used.

DESCRIPTION OF SYMBOLS 1 Tuner part 2 Main control part 3 Separation part 4 Video decoding part 5 Audio decoding part 6 Antenna 7 Information storage part 8 Input part 9 Display part 10 Speaker 11 Earphone output part 12 Bluetooth output part 13 Playback control part 14 Recording control part 15 Broadcasting Recording unit 16 Playback quality analysis unit 21 Broadcast receiving unit 22 Broadcast output unit

Claims (5)

A broadcast receiving unit that receives a broadcast wave including a weak layer stream that is a stream transmitted in a weak layer and a strong layer stream that is a stream transmitted in a strong layer;
Position identification information indicating the weak layer stream and the strong layer stream, positions of a plurality of I frames of these streams and identifiers for synchronizing the I frames, and reception quality when the broadcast wave is received A broadcast recording unit in which reception quality information is recorded;
A reproduction control unit that reads the weak layer stream and the strong layer stream recorded in the broadcast recording unit during reproduction;
Playback that selects one of the weak layer stream and the strong layer stream read by the playback control unit as a selected stream with reference to the position identification information and the reception quality information recorded in the broadcast recording unit The Quality Analysis Department,
Comprising
When the weak layer stream is selected as the selected stream, the reproduction quality analysis unit outputs an I frame immediately before deterioration, which is an I frame immediately before deterioration of reception quality among a plurality of I frames of the weak layer stream. When there is no synchronized I frame in the strong layer stream, the I frame before the deterioration-preceding I frame of the weak layer stream is specified as a switching I frame, and the selected stream is determined at the timing of the switching I frame. Switching from the weak layer stream to the strong layer stream;
A broadcast receiver characterized by that. The reproduction quality analysis unit selects the strong layer stream when the weak layer stream is selected as the selected stream and the strong layer stream does not have an I frame synchronized with the I frame immediately before the deterioration of the weak layer stream. The I frame immediately before the deterioration of the weak layer stream between the first frame and the second frame corresponding to the I frames before and after the I frame immediately before the deterioration of the weak layer stream among the plurality of I frames of the layer stream. An intermediate frame that can be synchronized to the weak layer stream, the I frame immediately before the deterioration of the weak layer stream is specified as the switching I frame, and the selected stream is synchronized with the strong layer from the weak layer stream at the timing of the switching I frame. Switch to stream,
The broadcast receiving apparatus according to claim 1. The reproduction quality analysis unit selects an I frame immediately after improvement, which is an I frame immediately after reception quality is improved, from among a plurality of I frames of the weak layer stream when the strong layer stream is selected as the selected stream. When there is no synchronized I frame in the strong layer stream, the I frame immediately after the improvement of the weak layer stream or the I frame immediately after the improvement is specified as the switching I frame, and the timing of the switching I frame is determined for the selected stream. To switch from the strong layer stream to the weak layer stream,
The broadcast receiving apparatus according to claim 1 or 2, characterized in that Receiving a broadcast wave including a weak layer stream that is a stream transmitted in a weak layer and a strong layer stream that is a stream transmitted in a strong layer;
Position identification information indicating the weak layer stream and the strong layer stream, positions of a plurality of I frames of these streams and identifiers for synchronizing the I frames, and reception quality when the broadcast wave is received Recording the reception quality information in the broadcast recording unit;
Reading the weak layer stream and the strong layer stream recorded in the broadcast recording unit during playback;
Selecting one of the weak layer stream and the strong layer stream as a selected stream with reference to the position identification information and the reception quality information recorded in the broadcast recording unit;
When the weak layer stream is selected as the selected stream, an I frame synchronized with an I frame immediately before deterioration, which is an I frame immediately before deterioration of reception quality, among the plurality of I frames of the weak layer stream is the strong frame. If it does not exist in the layer stream, the I frame before the I frame immediately before the deterioration of the weak layer stream is specified as the switching I frame, and the selected stream is identified from the weak layer stream at the timing of the switching I frame. Switching to a hierarchical stream;
A playback method using a broadcast receiving apparatus, comprising:   The program for making a broadcast receiver perform each step of the reproduction | regenerating method of Claim 4.

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