JP2011259296A - Digital broadcast receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a digital broadcast receiver which can output video and sound at a display timing which a layer of the switching destination originally has, after completing the switching between multiple layers to be simultaneously broadcasted.SOLUTION: A digital broadcast receiver includes: a time-lag specification part to specify a time-lag between two layers to be simultaneously broadcasted; an adjustment period determination part to determine an adjustment period to output video and sound generated from encoded video and audio stream of a layer whose display timing is set earlier than another layer, based on the time-lag, according to a hierarchical switching indication; an adjustment output part to output video and sound data of the layer whose display timing is set earlier by a first adjustment speed, which is faster by a first adjustment width than the standard speed, or by a second adjustment speed, which is slower by a second adjustment width than the standard speed, as substitute for video and sound data of a layer of a switching source, in the adjustment period; and a switching output part to output video and sound data of a layer of a switching destination by the standard speed in response with the ending of the adjustment period.

Description

  The present invention relates to a digital broadcast receiving apparatus that selectively outputs video / audio corresponding to one stream of video / audio streams transmitted divided into a plurality of layers.

  In digital broadcasting technology including terrestrial digital broadcasting, one channel can be divided into 13 segments, and a layer including one or more segments can be transmitted simultaneously up to three layers. Among broadcasts based on transmission systems divided into such layers, when the same program is broadcasted by a plurality of layers, it is called simulcast. A typical example of simultaneous broadcasting is a digital terrestrial broadcasting system that broadcasts the same television program in a so-called one-segment broadcasting hierarchy and a full-segment broadcasting hierarchy.

  In the terrestrial digital broadcasting system, different modulation schemes are adopted for one-segment broadcasting and full-segment broadcasting. For this reason, on the transmission side, a stream for one-segment broadcasting and a stream for full-segment broadcasting are separately encoded and modulated. Then, in the digital broadcast receiving apparatus provided with two sets of demodulation processing units and decoding processing units respectively corresponding to the one-segment broadcasting and the full-segment broadcasting, two layers to be simultaneously broadcast are received, and video / Audio can be selectively output. In such a digital broadcast receiving apparatus, for example, the two layers of streams can be switched according to the reception level and used to generate a video / audio signal to be provided to the user.

  The above-described two-layer streams to be simulcast are separately demodulated and decoded by the digital broadcast receiver. Therefore, the delay time from when the packets included in each stream are separated until the video / audio corresponding to the separated packets is generated is different from the two layers.

  In a conventional digital broadcast receiving apparatus, a stream with a shorter delay time or a generated video / audio signal is held in the buffer for the delay time described above, thereby facilitating switching between layers. (See Patent Documents 1 and 2).

JP 2007-180702 A JP 2008-206015 A

  By the way, PCR (Program Clock Reference) for designating display timing is set for each stream of one-segment broadcasting and full-segment broadcasting to be simulcast. That is, the scheduled display timing is originally different between the one-segment broadcasting and the full-segment broadcasting.

  Therefore, in the digital broadcast receiving apparatus to which the above-described conventional technology is applied, the display timing is adjusted to the side of the stream for which the slow display timing is set when switching between layers. That is, even when the stream with the slow display timing is switched to the stream with the fast display timing, the video / audio signal is output according to the slow display timing. In the conventional technique described above, the state delayed from the original display timing is continued as it is even after the switching is completed.

  An object of the present disclosure is to provide a digital broadcast receiving apparatus capable of outputting video / audio at the original display timing of a switching destination layer after completion of switching between a plurality of layers to be simulcast.

  The above-described object can be achieved by a digital broadcast receiving apparatus disclosed below.

  A digital broadcast receiving apparatus according to one aspect includes a time lag specifying unit that specifies a difference in display timing set in two layers of encoded video / audio streams being simultaneously broadcast as a time lag of two layers, and a video・ Videos generated from encoded video / audio streams in a hierarchy that has a display timing earlier than the other based on the time lag when switching of the encoded video / audio streams used for audio output is instructed. An adjustment period determining unit that determines an adjustment period for outputting audio, and video / audio data generated from the stream of the switching source layer used for outputting video / audio when switching is instructed in the adjustment period Instead of the encoded video / audio stream of the layer with the fast display timing set An adjustment output unit that outputs image / sound data at a first adjustment speed that is faster than the standard speed by the first adjustment width or a second adjustment speed that is slower than the standard speed by the second adjustment width; and at the end of the adjustment period. And a switching output unit that outputs video / audio data generated from the encoded video / audio stream of the switching destination layer specified by the instruction at a standard speed.

  According to the apparatus of the present disclosure, video / audio can be output at the original display timing of the switching destination layer after completion of switching between the plurality of layers to be simulcast.

It is a figure which shows one Embodiment of a digital broadcast receiver. It is a figure explaining the switching operation | movement to the hierarchy in which the early display timing was set. It is a figure explaining the switching operation from the hierarchy in which the early display timing was set. It is a figure which shows another embodiment of a digital broadcast receiver. It is a figure which shows another embodiment of a digital broadcast receiver. It is a flowchart showing an adjustment period determination process. 10 is a flowchart showing a decoding control operation of an elementary stream of layer X as a switching source. 10 is a flowchart showing a decoding control operation of an elementary stream of layer Y as a switching destination. It is a figure explaining the hierarchy switching from 1seg to full segment. It is a figure explaining hierarchy switching from full segment to one segment. 3 is a flowchart showing an audio / video output operation. It is a figure which shows another embodiment of an audio | voice decoding process part.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an embodiment of a digital broadcast receiving apparatus. The digital broadcast receiver shown in FIG. 1 includes a first layer reception processing unit 101 that receives a first layer broadcast signal that is simultaneously broadcast, and a second layer reception processing unit 102 that receives a second layer broadcast signal. It has.

  In the first layer reception processing unit 101 and the second layer reception processing unit 102, demodulation of a broadcast signal and TS (Transport Stream) separation processing are performed, and the first layer PES (Packetize Elementary Stream) and the second layer PES, respectively. And are generated.

  Below, the case where the display timing earlier than PES produced | generated from the broadcast signal of the 2nd hierarchy is set to the direction of PES produced | generated from the broadcast signal of the 1st hierarchy is demonstrated. The difference between the display timings set for the first-layer broadcast signal and the second-layer broadcast signal is specified by the time lag specifying unit 111.

  The time lag TL specified by the time lag specifying unit 111 is passed to the adjustment period determining unit 112. Based on this time lag TL, the adjustment period determination unit 112 speeds up the video / audio generated from the broadcast signal of the first layer described above by the adjustment output unit 113 based on this time lag TL. Determine the adjustment period to be adjusted and output.

  The adjustment output unit 113 receives the first-layer video PES to be adjusted and output from the first-layer reception processing unit 101, and finely converts the video PES to be adjusted and output via the video decoding processing unit 103 and the video output unit 104. Output at high speed or very low speed. Also, the adjustment output unit 113 receives the first layer audio PES to be adjusted and output from the first layer reception processing unit 101, and the adjustment output target audio PES through the audio decoding processing unit 105 and the audio output unit 106. Output at very low speed or very low speed.

  Further, after the adjustment output by the adjustment output unit 113 is completed, the switching output unit 114 outputs the video PES of the switching destination layer at a normal speed via the video decoding processing unit 103 and the video output unit 104. . Similarly, the switching output unit 114 outputs the audio PES of the switching destination hierarchy at a normal speed via the audio decoding processing unit 105 and the audio output unit 105.

  Next, the hierarchy switching operation by the digital broadcast receiving apparatus having the configuration as shown in FIG. 1 will be described.

  FIG. 2 is a diagram illustrating an operation for switching to a hierarchy in which an early display timing is set. FIG. 3 is a diagram for explaining the switching operation from the hierarchy where the early display timing is set.

  In the example of FIG. 2, when the video / audio generated from the second level PES (A) is being output, switching to the first level is instructed by the switching instruction. In FIG. 2, the switching instruction is indicated by an arrow with a symbol (1).

  A display timing earlier than that of the second level PES is set in the first level PES. Accordingly, the second level PES (B) corresponding to the first level PES (B) that arrives first after the switching instruction is input is delayed by a time lag TL between the first level and the second level. To reach. Therefore, until the timing when the second level PES (B) arrives, the video / audio generated from the second level PES is output at the standard speed, and then from the first level PES in the adjustment period provided thereafter. The generated video / audio is output faster than the standard speed.

  In the adjustment output unit 113 illustrated in FIG. 1, for example, the adjustment period determination unit 112 determines M adjustment output target PESs including the first level PES (B) illustrated in FIG. During the adjusted period, output is performed at a first adjustment speed that is faster than the standard speed by a first adjustment width. In the following description, outputting video / audio at a first adjustment speed that is faster than the standard speed by a first adjustment width in the adjustment period is referred to as fine high-speed output. Further, outputting video / audio at a standard speed before and after the adjustment period is referred to as normal output.

  At this time, the adjustment period determination unit 112 determines the period from the arrival timing of the second layer PES (B) to the arrival timing of the PES (C) following the adjustment output target PES described above in the first layer PES. It can be an adjustment period.

  During the adjustment period set in this way, the adjustment output unit 113 outputs the PES just before the first level PES (C) used as the adjustment layer at a very high speed. In this way, by finely outputting the PES of the adjustment layer for which the early display timing is set, the video / audio output timing provided to the user is set to the early display timing of the first layer after switching. You can catch up. Then, when the catch-up is started, the switching output unit 114 starts normal output of the first layer of the switching destination from the above-described PES (C), and thereafter the video is displayed according to the display timing set in the PES of the first layer.・ Sound can be output.

  On the other hand, in the example of FIG. 3, when the video / audio generated from the PES of the first layer is being output, switching to the second layer is instructed by the switching instruction. In FIG. 3, the switching instruction is indicated by an arrow with a symbol (1).

  In this case, the adjustment output unit 113 shown in FIG. 1 uses the standard speed for the video / audio generated from the first layer PES in the adjustment period provided in response to the input of the switching instruction in the first layer PES. Output too late. In the example shown in FIG. 3, the adjustment period is set according to the arrival timing of the first layer PES (B) that arrives for the first time after the switching instruction is input.

  For example, the adjustment output unit 113 generates m adjustment output target PESs including the PES (B) illustrated in FIG. 3 and the PESs that reach the PES (B) in the adjustment period determined by the adjustment period determination unit 112 from the standard speed. Is also output at a second adjustment speed that is slower by the second adjustment width. In the following description, outputting video / audio at a second adjustment speed that is slower than the standard speed by a second adjustment width in the adjustment period is referred to as a very low speed output.

  At this time, the adjustment period determining unit 112 starts from the timing at which the first-level PES (B) arrives, and the second-level PES (corresponding to the first-level PES (C) following the adjustment output target PES described above. The period until the arrival timing of C) can be set as the adjustment period.

  In the adjustment period set in this way, the adjustment output unit 113 outputs the PES immediately before the above-described PES (C) included in the ES of the first hierarchy used as the adjustment hierarchy at a very low speed. In this way, by outputting the ES of the adjustment layer with the early display timing set at a very low speed, the video / audio output timing provided to the user is matched with the later display timing of the second layer after switching. Thus, the time lag between the two hierarchies can be eliminated. When the deviation is eliminated, the switching output unit 114 starts the normal output of the second layer of the switching destination from the PES (C) described above, and thereafter the display set in the PES of the second layer is performed. Video / audio can be output according to the timing.

  As described above, in the digital broadcast receiving apparatus having the configuration as shown in FIG. 1, after the switching between the two hierarchies to be simulcast is completed, the video / video is received according to the original display timing set in the post-switching hierarchy. Audio output can be continued. In addition, by appropriately setting the first adjustment speed and the second adjustment speed applied to the above-described fine high-speed output and fine low-speed output, the video / audio output generated from the two levels of the PES is smoothly connected. It is possible.

  The digital broadcast receiving apparatus having the configuration as shown in FIG. 1 can be applied to a digital broadcast receiving apparatus for viewing digital terrestrial broadcasts, for example.

  FIG. 4 shows another embodiment of the digital broadcast receiving apparatus. 4 that are the same as those shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted. In digital terrestrial broadcasting, full-segment broadcasting PES has a display timing earlier than that of one-segment broadcasting PES. Therefore, the hierarchy corresponding to full segment broadcasting corresponds to the first hierarchy described above, and the hierarchy corresponding to one segment broadcasting corresponds to the second hierarchy. A layer corresponding to full segment broadcasting is used as a layer for adjustment.

  The one-seg tuner unit 211, the one-seg demodulation unit 212, the one-segment TS separation unit 213, and the one-seg PCR analysis unit 214 illustrated in FIG. 4 correspond to the second layer reception processing unit 102. Further, the full segment tuner unit 215, the full segment demodulation unit 216, the full segment TS separation unit 217, and the full segment PCR analysis unit 218 correspond to the first layer reception processing unit 101.

  The one-segment video PES separated by the one-segment TS separation unit 213 is transferred to the video decoding processing unit 103 via the one-segment video PES analysis unit 221 and the one-segment video ES storage unit 222. On the other hand, the one-segment audio PES separated by the one-segment TS separation unit 213 is passed to the speech decoding processing unit 105 via the one-segment audio PES analysis unit 226 and the one-segment audio ES storage unit 227.

  The full segment video PES separated by the full segment TS separation unit 217 is transferred to the video decoding processing unit 103 via the full segment video PES analysis unit 224 and the full segment video ES storage unit 225. On the other hand, the full segment audio PES separated by the full segment TS separation unit 217 is passed to the speech decoding processing unit 105 via the full segment audio PES analysis unit 229 and the full segment audio ES storage unit 230.

  The decoding control unit 231 controls the output of the PES from the above-described one-segment video ES storage unit 222 and full-segment video ES recording unit 225 to the video decoding processing unit 103 via the video decoding control unit 223. Also, the decoding control unit 231 controls the output of the PES from the above-described one-segment audio ES storage unit 227 and full-segment audio ES recording unit 230 to the speech decoding processing unit 105 via the audio decoding control unit 228. For the control processing of the decoding control unit 231, analysis results by the one-segment PCR analysis unit 214 and the full-segment PCR analysis unit 218 are used.

  In addition, in the digital broadcast receiving apparatus shown in FIG. 4, the video decoding processing unit 103 includes a configuration for sending the decoding result by the video decoding unit 232 to the video output unit 104 via the decoded video storage unit 233. The audio decoding processing unit 105 includes a configuration for sending the decoding result by the audio decoding unit 236 to the audio output unit 106 via the decoded audio storage unit 237.

  Output of decoded video data and decoded audio data from the above-described decoded video storage unit 233 and decoded audio storage unit 237 to the video output unit 104 and audio output unit 106 is controlled by the output control unit 235.

  Next, a description will be given of a method for realizing switching between one-segment broadcasting and full-segment broadcasting that are simulcast in the digital terrestrial broadcasting viewing digital broadcasting receiving apparatus having the configuration shown in FIG.

  FIG. 5 shows another embodiment of the digital broadcast receiving apparatus. Note that among the components shown in FIG. 5, components equivalent to those shown in FIGS. 1 and 4 are denoted by the same reference numerals and description thereof is omitted.

  The decoding control unit 231 illustrated in FIG. 5 includes an adjustment period determination unit 112, a hierarchy switching instruction unit 238, a switching control unit 239, and a setting information holding unit 241. The adjustment period determining unit 112 includes a start point specifying unit 121 that determines the timing that is the start point of the adjustment period, and an end point specifying unit 122 that determines the timing that is the end point of the adjustment period.

  For example, the layer switching instruction unit 238 receives information indicating the reception state of each layer from the one-segment tuner unit 211 and the full-segment tuner unit 215, and instructs switching between one-segment and full-segment based on this information. For example, the layer switching instruction unit 238 instructs the layer switching to the one-segment broadcasting in response to the information that the reception state of the full-segment broadcasting has deteriorated, and detects the recovery of the reception state of the full-segment broadcasting. It is possible to instruct to switch to the next level.

  The setting information holding unit 241 holds the time lag between the display timings set for the full-segment broadcasting and the one-segment broadcasting, and the values of the first adjustment width and the second adjustment width applied to the adjustment period described above. ing. One of the values of the first adjustment width and the second adjustment width is selected according to the type of the layer after switching indicated by the layer switching instruction unit 238, and the selected value is used by the switching control unit 239. To be provided to the processing of the output control unit 235. Further, the time lag value held in the setting information holding unit 241 is passed to the end point specifying unit 122 when the hierarchy switching instruction unit 238 is instructed to switch the hierarchy, and is used to determine the end timing of the adjustment period. That is, in the digital broadcast receiving apparatus shown in FIG. 5, the setting information holding unit 241 corresponds to the time lag specifying unit 111 shown in FIG. The processing by the adjustment period determining unit 112 also uses the analysis result by the one-segment PCR analysis unit 214 and the analysis result by the full-seg PCR analysis unit 218.

  The switching control unit 239 controls the operations of the video decoding control unit 223 and the audio decoding control unit 228 based on the timing determined by the start point specifying unit 121 and the end point specifying unit 122. Accordingly, an appropriate decoding target video PES is passed from the one-segment video ES storage unit 222 or the full-segment video ES storage unit 225 to the video decoding unit 232 according to the layer switching stage. Similarly, the output of the audio PES from the one-segment video ES storage unit 222 or the full-segment video ES storage unit 225 is controlled, and an appropriate decoding target PES is passed to the audio decoding unit 236 according to the layer switching stage.

  As described above, in the digital broadcast receiving apparatus shown in FIG. 5, the configuration in which the switching control unit 239 controls the above-described units related to the video ES processing of both layers and the units related to the audio ES processing is shown in FIG. 1. This corresponds to the switching output unit 114.

  Also, the output control unit 235 illustrated in FIG. 5 decodes from the decoded video storage unit 233 and the decoded audio storage unit 237 based on the first adjustment width or the second adjustment width received via the switching control unit 239, for example. The speed at which data is output can be controlled. That is, in the digital broadcast receiving apparatus shown in FIG. 5, the configuration in which the output control unit 235 controls the decoded data output by the decoded video storage unit 233 and the decoded audio storage unit 237 based on information from the switching control unit 239. This corresponds to the adjustment output unit 113 shown in FIG.

  FIG. 6 is a flowchart showing the adjustment period determination process. Hereinafter, the process of determining the adjustment period will be described with reference to FIG.

  When the hierarchy switching instruction is received from the hierarchy switching instruction unit 238 (step 301), the adjustment width n selected corresponding to the time lag TL and the switching destination hierarchy is passed from the setting information holding unit 241 to the end point specifying unit 122. It is. For example, when switching from one segment to full segment is instructed, the setting information holding unit 241 passes the value of the first adjustment width for fine high-speed output to the end point specifying unit 122 as the adjustment width n. On the other hand, when switching from full segment to one segment is instructed, the setting information holding unit 241 passes the value of the second adjustment width for the low-speed output to the end point specifying unit 122 as the adjustment width n. For example, the end point specifying unit 122 can calculate the length L (= TL / n) of the adjustment period by dividing the time lag TL by the adjustment width n (step 302).

Further, the difference Tp is calculated by subtracting the PCRx of the switching source hierarchy X from the PCRy of the switching destination hierarchy Y designated by the hierarchy switching instruction (step 303). Also, the switching control unit 239, via the video decoding control unit 223, indicates a time indicated by a PTS (Presentation Time Stamp) set in the video PES that is separated for the first time after switching from the full-segment broadcasting TS used as the adjustment layer. T _a1 is received (step 304).

Next, the switching control unit 239 determines the type of hierarchy switching based on the hierarchy switching instruction (step 305). For example, when an instruction is given to switch from the full segment hierarchy with early display timing to the one segment hierarchy with late display timing (affirmative determination in step 305), the start point specifying unit 121 calculates the start point of the adjustment period according to step 306. At this time, the start point specifying unit 121 sets the above-described time _Ta1 as the start point _Tx1 of the adjustment period in the switching source hierarchy. Then, the difference Tp calculated in step 303 is added to the above-described time T _a1 to calculate the adjustment point start point T _y1 in the switching destination hierarchy.

On the other hand, when an instruction to switch from the one-segment layer with late display timing to the full-segment layer with early display timing is given (negative determination at step 305), the start point specifying unit 121 calculates the start point of the adjustment period according to step 307. At this time, the start point specifying unit 121 sets the value obtained by subtracting the PCR difference Tp from the time _Ta1 described above as the start point _Tx1 of the adjustment period in the switching source hierarchy. The time T _a1 described above is set as the start point T _y1 of the adjustment period in the switching destination hierarchy.

After the start point of the adjustment period is calculated in this way, the end point specifying unit 122 adds the length L of the adjustment period to the above-described start points T _x1 and T _y1 , respectively, in the switching source and switching destination hierarchies. The end points T _x2 and T _y2 of the adjustment period are calculated (step 308).

  The start point and end point of the adjustment period calculated in this way are notified to the video decoding control unit 223, the audio decoding control unit 228, and the output control unit 235 via the switching control unit 239 (step 309). Further, the adjustment width n described above is also notified to the output control unit 235 via the switching control unit 239 (step 310).

  In this way, in the full-segment hierarchy corresponding to the first hierarchy, the adjustment periods to be applied to the switching source hierarchy and the switching destination hierarchy based on the TPS set for the video PES that arrives for the first time after the hierarchy switching instruction is set. Can be set.

  Next, the decoding control operation for the elementary stream of each layer before and after layer switching will be described.

  FIG. 7 is a flowchart showing the decoding control operation of the elementary stream of layer X as a switching source. FIG. 8 is a flowchart showing the decoding control operation of the elementary stream of layer Y at the switching destination. Note that the control process associated with the layer switching is the same for the process for the video PES and the process for the audio PES. Therefore, FIGS. 7 and 8 show the control process for the video PES as a representative. It was.

  First, with reference to FIG. 7, the decoding control process for the PES of the switching source hierarchy X will be described.

  Every time the switching source layer X video PES separated from the TS in step 311 is received, the video decoding control unit 223 determines whether the layer X is a layer for which an early display timing is set (step 312). ).

  When switching from full segment to one segment is instructed, the full segment video PES separated by the full segment TS separation unit 217 and sequentially stored in the full segment video ES storage unit 225 becomes the video PES of the hierarchy X.

As described above, when the earlier display timing is set for the switching source hierarchy X (affirmative determination in step 312), the switching source hierarchy X becomes the adjustment hierarchy. In this case, the video decoding control unit 223 compares the scheduled display time Tsx indicated by the PTS set in this video PES with the end point T _x2 of the adjustment period of the hierarchy X described above (step 313).

When the scheduled display time Tsx of the video PES is before the end point T _{x2 of the} adjustment period (affirmative determination in step 313), the video PES is displayed in accordance with an instruction from the video decoding control unit 223. The data is passed to the decryption unit 232 (step 314). For example, the video decoding unit 223 can send the video PES to the video decoding unit 232 by instructing the full segment video ES storage unit 225 in which the video PES of the hierarchy X is stored to output the video PES. . On the contrary, when the scheduled display time Tsx of the video PES is after the end point T _{x2 of the} adjustment period (No determination in step 313), the video decoding control unit 223 displays the video ES storage unit corresponding to the video PES. (Step 316). Thereafter, the video decoding control unit 223 ends the processing for the video PES and waits for the arrival of the next video PES.

On the other hand, when switching from one seg to full seg is instructed, the one seg video PES separated by the one seg TS separation unit 213 and sequentially stored in the one seg video ES storage unit 222 becomes the video PES of the hierarchy X. As described above, when the later display timing is set for the switching source hierarchy X (No in Step 312), the switching destination hierarchy Y becomes the adjustment hierarchy. In this case, the video decoding control unit 223 compares the scheduled display time Tsx indicated by the PTS of the video PES with the start point T _x1 of the adjustment period for the hierarchy X (step 315). When the scheduled display time Tsx of this video PES is before the start point T _{x1 of the} adjustment period (affirmative determination in step 315), the PES in the hierarchy X is video according to an instruction from the video decoding control unit 223. The data is passed to the decryption unit 232 (step 314). On the other hand, when the scheduled display time Tsx of the video PES is after the start point T _{x1 of the} adjustment period (No determination in step 315), the video decoding control unit 223 displays the video PES corresponding to the video ES storage unit. (Step 316). Thereafter, the video decoding control unit 223 ends the processing for the video PES and waits for the arrival of the next video PES.

  Next, with reference to FIG. 8, the decoding control process for the PES of the switching destination hierarchy Y will be described.

  Each time the video PES of the switching destination layer Y separated from the TS in step 321 is received, the video decoding control unit 223 determines whether the layer Y is a layer for which an early display timing is set (step 322). ).

  When switching from one segment to full segment is instructed, the full segment video PES separated by the full segment TS separation unit 217 and stored in the full segment video ES storage unit 225 becomes the video PES of layer Y. As described above, when the earlier display timing is set for the switching destination hierarchy Y (affirmative determination in step 322), the switching destination hierarchy Y becomes the adjustment hierarchy. At this time, the video PES to be adjusted and output in the layer Y used as the adjustment layer is passed to the video decoding unit 232 after the last video PES to be output in the switching source layer X as follows. Can be controlled.

For example, the video decoding control unit 223 compares the scheduled display time Tsy indicated by the PTS set in the header of the video PES with the start point T _{y1 of} the layer Y adjustment period described above (step 323). Then, when the scheduled display time Tsy is after the start point T _{y1 of the} adjustment period (affirmative determination in step 323), the video decoding control unit 223 further performs a determination process in step 324. In step 324, the video decoding control unit 223 compares the scheduled display time Tsx indicated by the PTS of the PES separated from the TS of the switching source hierarchy X with the start point T _x1 of the adjustment period for the hierarchy X. When the scheduled display time Tsx described above is after the start point T _x1 of the adjustment period for the hierarchy X (affirmative determination in step 324), the video decoding control unit 223 determines that the PES corresponding to the start point of the adjustment period for the hierarchy X is Judge that it has reached. In this case, the video decoding control unit 223 instructs the video decoding unit 232 to output the video PES of the layer Y input in step 321 to the video ES storage unit corresponding to the layer Y. (Step 325).

In addition, when the scheduled display time Tsx of the PES on the layer X side is before the adjustment period start point T _x1 (negative determination in step 324), the video decoding control unit 223 reaches the PES corresponding to the start point of the adjustment period of the layer X. Then, the process proceeds to step 325. For example, the video decoding control unit 232 instructs the video ES storage unit corresponding to the layer Y to store the PES of the layer Y, and after the affirmative determination is made in step 324, the stored PES is output collectively. You can also. Thereafter, the video decoding control unit 223 ends the processing for the video PES and waits for the arrival of the next video PES.

When the scheduled display time Tsy of the PES in the hierarchy Y is before the start point T _{y1 of the} adjustment period (No determination in step 323), the video decoding control unit 223 deletes the video PES received in step 321. May be.

  On the other hand, when switching from full segment to one segment is instructed, the one segment video PES separated by the one segment TS separation unit 213 and stored in the one segment video ES storage unit 222 becomes the video PES of the layer Y. As described above, when the later display timing is set for the switching destination hierarchy Y (No in Step 322), the switching source hierarchy X becomes the adjustment hierarchy. At this time, control is performed as follows so that the video PES of the switching destination layer Y is passed to the video decoding unit 232 after the video PES corresponding to the end point of the adjustment period of the layer X used as the adjustment layer. can do.

For example, the video decoding control unit 223 compares the scheduled display time Tsy indicated by the PTS of the received video PES with the end point T _y2 of the adjustment period for the layer Y (step 326). When the scheduled display time Tsy is after the end point T _{y2 of the} adjustment period (affirmative determination in step 326), the video decoding control unit 223 further performs a determination process in step 327. In step 327, the video decoding control unit 223 compares the scheduled display time Tsx indicated by the PTS of the PES separated from the TS of the switching source hierarchy X with the end point T _x2 of the adjustment period for the hierarchy X. When the above-described scheduled display time Tsx is after the end point T _x2 of the adjustment period of the hierarchy X (affirmative determination in step 327), the video decoding control unit 223 performs the adjustment output target included in the adjustment period of the hierarchy X It is determined that the PES has already been passed to the video decoding unit 232. In this case, the video decoding control unit 223 proceeds to step 325 and passes the video PES of the layer Y input at step 321 to the video decoding unit 232.

Further, when the scheduled display time Tsx of the PES on the layer X side is equal to or less than the end point T _{x2 of the} adjustment period (negative determination in step 327), the video decoding control unit 223 reaches the PES corresponding to the end point of the adjustment period of the layer X Then, the process proceeds to step 325. For example, the video decoding control unit 232 instructs the video ES storage unit corresponding to the layer Y to store the PES of the layer Y, and after the affirmative determination is made in step 324, the stored PES is output collectively. You can also. On the other hand, when the scheduled display time Tsy of the PES of the hierarchy Y described above is before the end point T _{y2 of the} adjustment period (No determination in step 326), the video decoding control unit 223 deletes the video PES received in step 321. (Step 328). Thereafter, the video decoding control unit 223 ends the processing for the video PES and waits for the arrival of the next video PES.

  As described above, depending on which of the switching source hierarchy X and the switching destination hierarchy Y is the adjustment hierarchy, an appropriate one of the PESs separated from the TSs of both hierarchies is selectively selected. It can be passed to the video decoder.

FIG. 9 is a diagram for explaining layer switching from one segment to full segment. FIG. 10 is a diagram for explaining layer switching from full segment to one segment. In FIGS. 9 and 10, the timing at which the hierarchy switching instruction is input is indicated by arrows. One-segment PES is indicated by a white rectangle, and full-segment PES is indicated by a shaded rectangle. Individual rectangular, hierarchy X, the starting point T _x1, T _y1 or end point T _x1, T _y1 adjustment period in the Y as a base point, given the ordinal number with a negative value in PES to reach before each On the contrary, the PES that arrives later is shown with an ordinal number having a positive value.

In the example shown in FIG. 9, the one-segment hierarchy is the switching source hierarchy X, and the full-segment hierarchy is the switching destination hierarchy Y. As described above, when the early display timing is set in the hierarchy Y after switching, the adjustment period is the timing when the one-segment PES (T _x1 ) corresponding to the start point of the adjustment period on the one-segment side of the switching source arrives. Be started. The full-segment PES that has arrived prior to the arrival of the one-segment PES (T _x1 ) described above and that arrives after the start of the adjustment period is held in the full-segment ES storage unit. These full-segment PES reaches the one-segment PES described above (T _x1), after which the immediately preceding one-segment PES seg _{PES (T x1) (T x1} -1) was passed to the audio-video decoding unit, sequentially It is passed to the audio / video decoding unit.

In the example of FIG. 9, the PES (T _y2 −1) immediately before the full segment PES (T _y2 ) corresponding to the end point of the adjustment period from the full segment PES (T _y1 ) corresponding to the start point of the adjustment period on the full segment side is described later. This is the PES to be output. On the other hand, one-segment PES (T _x1 -1) each Furusegu PES of each seg PES and Full Seg PES (T _y2) subsequent to the immediately preceding one-segment PES described above (T _x1) are respectively output at the standard speed.

On the other hand, in the example illustrated in FIG. 10, the full segment hierarchy is the switching source hierarchy X, and the one segment hierarchy is the switching destination hierarchy Y. In this way, when an early display timing is set in the switching source hierarchy X, the adjustment period is the timing when the full segment PES (T _x1 ) corresponding to the starting point of the adjustment period on the switching source full segment side arrives. Be started. Then, each PES up to the PES (T _x2 -1) immediately before the full segment PES (T _x2 ) corresponding to the end point of the adjustment period on the full segment side is connected to the audio / video via the full segment ES storage unit according to the arrival of each PES. Passed to the decryption unit. Thereafter, the one-segment PES (T _y2 ) corresponding to the end of the adjustment period on the one-segment side and each subsequent one-segment PES are sequentially transferred to the audio / video decoding unit via the one-segment ES storage unit.

In the example of FIG. 10, the PES (T _x2 −1) immediately before the full segment PES (T _x2 ) corresponding to the end point of the adjustment period from the above-described full segment PES (T _x1 ) is the adjustment output target PES. On the other hand, one-segment PES Full-Seg PES (T _x1 -1) each full-segment PES and Seg PES up (T _y2) since immediately before the full-segment PES described above (T _x1) are output at the standard speed.

  Next, the output operation of audio / video decoded data based on the full segment / one segment video PES and the full segment / one segment audio PES passed to the video decoder 232 and the audio decoder 236 as described above will be described.

  FIG. 11 is a flowchart showing the audio / video output operation. In the following description, audio decoded data and video decoded data are collectively referred to as decoded data.

The output control unit 235 outputs the count value CNT of the internal counter and the adjustment period in the switching source hierarchy X each time the decoded data generated from the audio / video PES of the switching source hierarchy X is output at the standard speed (step 331). _Is compared with the starting point T _x1 of the current (step 332). Then, while the count value CNT is less than the starting point T _x1 (negative determination at step 332), step 331 and step 332 are repeated.

Thereafter, when the count value CNT becomes _{equal to} or greater than the start point T _x1 (Yes determination at step 332), the process proceeds to step 333. At this time, the output control unit 235 determines whether or not the switching destination hierarchy Y is an early hierarchy for which an early display timing is set (step 333). Only in the case of an affirmative determination in step 333, the start point T _y1 of the adjustment period in the switching destination hierarchy Y is set to the count value CNT of the internal counter (step 334).

  Next, the output control unit 235 changes the count-up speed N of the internal counter using the adjustment width n notified from the switching control unit 239 in step 310 shown in FIG. 6 (step 335). At this time, for example, when a hierarchy switching from one segment to a full segment is instructed, the count-up speed is increased based on the first adjustment width notified as the adjustment width n corresponding to the switching to the earlier hierarchy. Will be changed as follows. On the other hand, when hierarchy switching from full segment to one segment is instructed, the count-up speed is changed to be reduced based on the second adjustment width notified as the adjustment width n corresponding to the switching from the earlier hierarchy Is done.

  Thereafter, the output control unit 235 outputs the decoded data of the early hierarchy used as the adjustment hierarchy according to the count value CNT of the internal counter counted up at the speed changed as described above (step 336). For example, the output control unit 235 compares the count value CNT of the internal counter with the scheduled display time indicated by the PTS set in the decoded data held in the decoded audio / video storage unit, and outputs the matched decoded data. be able to. Each time each piece of decoded data is output, the output control unit 235 determines whether or not the count value CNT is equal to or greater than the value corresponding to the end point of the adjustment period in the earlier hierarchy (step 337). In the case of negative determination in step 337, the output control unit 235 determines that the adjustment period has not ended yet, returns to step 336, and outputs the next decoded data.

When the count value CNT reaches a value corresponding to the end point of the adjustment period (affirmative determination in step 337), the output control unit 235 again sets an early display timing for the switching destination hierarchy Y. It is determined whether or not it is a hierarchy (step 338). Only in the case of negative determination in step 338, the end point T _y2 of the adjustment period in the switching destination hierarchy Y is set in the count value CNT of the internal counter (step 339).

  Next, the output control unit 235 changes the count-up speed N of the internal counter to 1 which is the standard value (step 340). Thereafter, the decoded data of the layer Y to be switched to is output as audio / video at the standard speed. (Step 341).

  In the example described above, the output control unit 235 controls the speed at which the decoded data is output from the decoded video data storage unit 233 and the decoded audio storage unit 237 to the video output unit 105 and the audio output unit 106. As a result, the section where the decoded data of the hierarchy X that is the switching source is normally output and the decoded data of the hierarchy Y after the switching are normally output across the adjustment period in which the decoded data of the early hierarchy for adjustment is output at the adjustment speed. It is possible to connect the sections to be output while maintaining the continuity of the scene.

  Note that the value held as the first adjustment width in the setting information holding unit 241 illustrated in FIG. 5 is, for example, an upper limit that is a value that gives a count-up speed equivalent to the maximum decoding speed of the video PES by the video decoding unit 232. It can be set in advance. By setting the first adjustment width according to such a condition, it is possible to realize a very high speed output within the range of the performance of the video decoding unit 232. On the other hand, the first adjustment width can be suppressed to such an extent that the very high-speed output during the adjustment period does not give the user an unnatural impression. Further, for example, the first adjustment width can be changed stepwise within the adjustment period so that the first adjustment speed becomes the highest near the center of the adjustment period.

  The value held as the second adjustment width in the setting information holding unit 241 can be set in advance in consideration of the amount of decoded video data that can be stored in the decoded video storage unit 233, for example. By setting the second adjustment width in accordance with such a condition, it is possible to realize a low-speed output within the capacity range of the decoded video storage unit 233. On the other hand, the second adjustment width can be suppressed to such an extent that the low-speed output during the adjustment period does not give the user an unnatural impression. Furthermore, for example, the second adjustment width can be changed stepwise within the adjustment period so that the second adjustment speed becomes the slowest near the center of the adjustment period.

  In addition, the audio decoding data stored in the decoded audio storage unit 237 can be adjusted in advance in consideration of the speed at which each audio decoding data is output in advance.

  FIG. 12 shows another embodiment of the speech decoding processing unit. Note that, among the components shown in FIG. 12, components equivalent to those shown in FIG. 5 are denoted by the same reference numerals and description thereof is omitted.

  The audio decoding unit 236 illustrated in FIG. 12 includes a silence insertion unit 131, a silence deletion unit 132, and an audio data generation unit 133. The output control unit 235 includes an editing control unit 242, a counter control unit 243, a counter 244, and an output instruction sending unit 245.

  The counter control unit 243 of the output control unit 235 controls the counting operation of the counter 244 based on the PTS value of each layer indicating the start point and end point of the adjustment period and the adjustment width n. The output instruction sending unit 245 instructs the decoded audio storage unit 237 and the decoded video storage unit (not shown) to output decoded data every time the count value CNT of the counter 244 is counted up.

  On the other hand, the edit control unit 242 receives the adjustment width n via the counter control unit 243, and the count value CNT of the counter 244 indicates a period during which the decoded data of the adjustment layer is output. An editing process based on the adjustment width n is instructed. For example, when the count-up speed N is increased by the adjustment width n, the edit control unit 242 corresponds to the adjustment width n from the decoded audio data generated by the audio data generation unit 133 with respect to the silence deletion unit 132. Instruct to delete the silent period of the length. On the other hand, when the count-up speed N is reduced by the adjustment width n, the edit control unit 242 corresponds to the adjustment width n for the decoded audio data generated by the audio data generation unit 133 with respect to the silence insertion unit 131. Instruct to insert a silent period of the desired length.

  In this way, the length of the decoded audio data stored in the decoded audio storage unit 237 can be adjusted according to the count-up speed when each decoded audio data is output. The decoded audio data whose length has been adjusted in this way is sequentially output in accordance with an instruction from the output instruction sending unit 245 and is passed to the audio output unit 106.

  The digital broadcast receiving device having the configuration as described above can be applied to a vehicle-mounted digital broadcast receiving device, a car navigation device having a digital broadcast receiving function, and the like. According to such a vehicle-mounted digital broadcast receiving device or a car navigation device having a digital broadcast receiving function, a hierarchy can be obtained without impairing the continuity of a scene in accordance with a change in the reception state of two layers that are simultaneously broadcast. Can be switched. Moreover, as described above, after the layer switching is completed, the video / audio can be output in accordance with the original display timing of the switching destination layer, so that the user can view the digital terrestrial broadcast more comfortably even while moving. be able to.

101 first layer reception processing unit 102 second layer reception processing unit 103 video decoding processing unit 104 video output unit 105 audio decoding processing unit 106 audio output unit 111 time lag specifying unit 112 adjustment period determining unit 113 adjustment output unit 114 switching output unit 121 Start point identification unit 122 End point identification unit 131 Silence insertion unit 132 Silence deletion unit 133 Audio data generation unit 211 One segment tuner unit 212 One segment demodulator 213 One segment TS separation unit 214 One segment PCR analysis unit 215 Full segment tuner unit 216 Full segment demodulator 217 Full segment TS separation Unit 218 full segment PCR separation unit 221 one segment video PES analysis unit 222 one segment video ES storage unit 223 video decoding control unit 224 full segment video PES analysis unit 225 full segment video ES storage unit 226 one segment O PES analysis unit 227 One segment audio ES storage unit 228 Audio decoding control unit 229 Full segment audio PES analysis unit 230 Full segment audio ES storage unit 231 Decoding control unit 232 Video decoding unit 233 Decoded video storage unit 235 Output control unit 236 Audio decoding unit 237 Decoding Audio storage unit 238 Hierarchy switching instruction unit 239 Switching control unit 241 Setting information holding unit 242 Editing control unit 243 Counter control unit 244 Counter 245 Output instruction sending unit

Claims (5)

A time lag specifying unit for specifying a difference between display timings set in the encoded video / audio streams of two layers being simulcast as a time lag of the two layers;
When an instruction to switch the encoded video / audio stream used for video / audio output is given, it is generated from the encoded video / audio stream of the layer in which earlier display timing is set based on the time lag. An adjustment period determining unit for determining an adjustment period for outputting video and audio;
In the adjustment period, the early display timing is set instead of the video / audio data generated from the stream of the switching source layer used for outputting the video / audio when the switching is instructed. The video / audio data generated from the encoded video / audio stream of the hierarchy is processed at the first adjustment speed that is faster than the standard speed by the first adjustment width or at the second adjustment speed that is slower than the standard speed by the second adjustment width. An adjustment output unit to output,
A switching output unit that outputs video / audio data generated from an encoded video / audio stream of a switching destination layer designated by the instruction at the standard speed according to the end of the adjustment period;
A digital broadcast receiver characterized by comprising: The digital broadcast receiver according to claim 1,
The adjustment period determination unit
In the encoded video / audio stream of the hierarchy in which the early display timing is set, the encoded video / audio of the switching source hierarchy is based on the order information indicating the position of the packet that has reached the time when the switching is instructed. A start point specifying unit that specifies a time point when a packet specified by the order information is output in an audio stream as a start point of the adjustment period;
An end point specifying unit that specifies the end point of the adjustment period based on a time point obtained by dividing the time lag by the first adjustment width or the second adjustment width from the start point;
A digital broadcast receiver characterized by comprising: The digital broadcast receiver according to claim 1,
The adjustment output unit includes:
When the video / audio data is output at the first adjustment speed in the adjustment period, the silent state included in the audio data generated from the encoded video / audio stream of the layer in which the fast display timing is set is shown. A silence deletion unit for deleting an audio data transmission unit according to a ratio between the standard speed and the first adjustment speed;
When the video / audio data is output at the second adjustment speed in the adjustment period, the standard speed and the audio data generated from the encoded video / audio stream of the layer in which the fast display timing is set are added. A silence insertion unit for inserting a voice data transmission unit indicating a silence state according to a ratio to the second adjustment speed;
A digital broadcast receiver characterized by comprising: The digital broadcast receiver according to claim 1,
The adjustment output unit determines the first adjustment width based on a processing speed of decoding video data used for output from one of the encoded video / audio streams of the two layers. A digital broadcast receiver. The digital broadcast receiver according to claim 1,
The adjustment output unit determines the second adjustment width based on a storage capacity that can be allocated to hold video data used for output from one of the encoded video / audio streams of the two layers. A digital broadcast receiver characterized by the above.

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