JP6530292B2 - Broadcast receiving apparatus and broadcast receiving method - Google Patents

Description

  The present invention relates to a broadcast receiving apparatus and a broadcast receiving method.

  MPEG4-AAC (Moving Picture Experts Group 4-Advanced Audio Coding) (1ch, 2ch, 5.1ch, 7.1ch, 22.2ch) as a profile of Audio Stream in a digital television broadcasting system in advanced BS / highband CS broadcast. Adoption of MPEG4 ALS (Moving Picture Experts Group 4-Audio Lossless Coding) (2ch, 5.1ch) is planned. As a means for outputting these Audio Streams from the receiver to an external audio device (including an AV amplifier, a sound bar, etc.), an optical cable / coaxial cable compliant with the S / PDIF (Sony Philips Digital Interface) standard or HDMI ( It becomes transmission by the HDMI cable standardized by (registered trademark) -Forum (High-Definition Multimedia Interface-Forum). In either case, the transmission system of signals is standardized by IEC61937.

  However, the bit rate of Audio Stream that can be transmitted by the current S / PDIF standard is up to about 1.5 Mbps, and in the case of MPEG4-AAC, transmission can be performed by the current S / PDIF standard up to 7.1 ch. However, with the 22.2 ch, the bit rate is too low to transmit. For this reason, the IEC 61937 has been revised, and studies are underway to double the clock frequency during transmission to extend the transmission rate to about 3 Mbps. Furthermore, in the case of 5.1ch of MPEG4-ALS, since the maximum bit rate of Stream is about 7.3 Mbps, studies are also underway to support a transmission clock frequency up to 8x so that it can be transmitted.

ARIB STD-B 63 1.1 version revised on March 17, 2015, Radio Industries Association of Japan ARIB STD-B60 1.0 version July 31, 2014 formulated by the media transport method standard by MMT in digital broadcasting, The Japan Radio Industry Association

  By the way, when the double mode and the double mode of the transmission clock are defined in the above-mentioned IEC 61937, a broadcast receiving apparatus and an audio device capable of transmitting up to MPEG4-ALS 5.1 ch can be manufactured according to the standard. However, in order to operate the transmission clock at 2 × speed or 8 × speed, it is necessary to adopt a dedicated part or the like, which increases the cost of the product.

  Also, in the actual broadcasting, considering that most of the audio is MPEG4-AAC 2ch or 5.1ch, in the case of cost-effective audio equipment, up to 1.5 Mbps equivalent to the conventional one up to 1.5 Mbps can be supported. It is desirable that the distinction be made such that double-speed or 8-fold speed is supported only for high-end models that support MPEG4-AAC 22.2 ch or MPEG4-ALS. However, when an audio device is connected to the receiving device by an optical cable or coaxial cable, the means for the receiving device to know how many times the connected audio device supports (which profile corresponds to) Absent. Therefore, unless the receiver performs some setting by the user operation, the double-speed mode audio is output to the audio device not supporting the double-speed mode audio, and there is a problem that no sound is output during a certain broadcast program. It will occur.

  That is, in a broadcast receiving apparatus that receives a broadcast in which the first audio signal and the second audio signal are selectively transmitted, and outputs the received audio signal to an externally connected audio device, the broadcast receiving device with the externally connected audio device Between the first transmission clock frequency and the second transmission clock frequency as the transmission clock frequency of the audio signal transmission between them, and the first audio signal can be transmitted at both the first transmission clock frequency and the second transmission clock frequency If the second audio signal can be transmitted only at the second transmission clock frequency, the audio signal is output at the second transmission clock frequency to the audio device not compatible with the second transmission clock frequency. The problem is that there is no sound.

  The purpose of this embodiment is to use the first transmission clock frequency and the second transmission clock frequency as the transmission clock frequency of audio signal transmission to and from the externally connected audio device, and the first audio signal is the first transmission. Suitable for the corresponding transmission clock frequency of the connected audio device, if it can be transmitted at both the clock frequency and the second transmission clock frequency and the second audio signal can be transmitted only at the second transmission clock frequency It is an object of the present invention to provide a broadcast receiving apparatus and a broadcast receiving method capable of outputting an audio signal received in a form.

  An embodiment is a broadcast receiving apparatus that receives a broadcast in which a first audio signal and a second audio signal are selectively transmitted, and outputs the received audio signal to an externally connected audio device, the external connection being the external connection The first transmission clock frequency and the second transmission clock frequency are the transmission clock frequencies of the audio signal transmission to and from the audio device, and the first audio signal has the first transmission clock frequency and the second transmission clock frequency. When the second audio signal can be transmitted only at the second transmission clock frequency, the control unit may control the audio device to correspond to only the first transmission clock frequency. The audio device is classified into one mode and a second mode corresponding to both the first transmission clock frequency and the second transmission clock frequency, and the connected audio device is in the first mode. If the received audio signal is a first audio signal, the audio signal is output according to the first transmission clock frequency, and the connected audio device is received in a second mode. If the audio signal is a first audio signal, the transmission clock frequency is determined to output the audio signal according to the second transmission clock frequency.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which shows the structure of the broadcast reception apparatus in advanced BS / advanced wideband CS broadcast which concerns on embodiment. FIG. 2 is a block diagram for explaining switching of an audio profile when the broadcast receiving apparatus shown in FIG. 1 and an AV amplifier are connected. The figure which shows operation | movement at the time of receiving the broadcast which an audio | voice asset (audio | voice mode) changes from AAC 2ch to ALS 2ch in the broadcast receiving apparatus and external AV amplifier in a conventional system. The figure which shows operation | movement at the time of receiving the broadcast which audio | voice mode changes from MPEG4-AAC 2ch to MPEG4-AAC 5.1ch in the broadcast receiving apparatus and external AV amplifier in a conventional system. The figure which shows operation | movement at the time of receiving the broadcast in which the audio mode changes from MPEG4-AAC 2ch to MPEG4-AAC 22.2ch in the broadcast receiving apparatus and external AV amplifier in a conventional system. FIG. 7 is a diagram showing an operation when receiving a broadcast that changes from AAC 2 ch to AAC 22.2 ch when the profile is in the B connection mode in the broadcast receiving apparatus shown in FIG. 1. FIG. 7 is a diagram showing an operation when receiving a broadcast that changes from AAC 2 ch to AAC 22.2 ch when the profile is in the A connection mode in the broadcast receiving apparatus shown in FIG. 1. The flowchart for demonstrating the prior mode setting of a profile in the broadcast receiving apparatus shown in FIG. The flowchart for demonstrating the switching process at the time of broadcast reception in the broadcast receiving apparatus shown in FIG.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  The broadcast receiving apparatus according to the embodiment will be described below with reference to FIGS. 1 to 9.

  FIG. 1 is a block diagram showing the configuration of a broadcast receiving apparatus 1 in advanced BS / high-bandwidth CS broadcasting as an embodiment. This broadcast receiving apparatus receives a received signal of a broadcast wave obtained by a receiving antenna (not shown), and demodulates the TLV stream by performing demodulation processing and error correction decoding processing in the demodulation section 11, and the TLV / MMT separation section 12 Separate the video stream and the audio stream from this TLV stream.

  The TLV / MMT separation unit 12 separates TLV (Type Length Value) packets and MMT (MPEG Media Transport) packets from the audio stream and sends them to the audio selection control unit 13 respectively. The audio selection control unit 13 selects one asset to be applied to the AV amplifier 2 of the output destination from the plurality of audio assets based on the TLV information of the TLV packet and the MMT information of the MMT packet, Output to each external output system.

  In the internal reproduction system, the decoder 14 decodes the selected audio asset, and if the decoded output is 5.1 ch PCM data, the down mixer (DMIX) unit 15 converts it into 2 ch PCM data and sends it to the switching unit 16 If it is PCM data of 2ch, it will send to the switching part 16 directly. The switching unit 16 selects either 2ch from the down mixer unit 15 at the input or 2ch directly supplied from the decoder 14 based on the instruction from the audio selection control unit 13 and outputs at the output an internal reproduction system, an external Select one of the output systems.

  The PCM data of 2ch selected and output to the internal reproduction system by the switching unit 16 is converted to an analog audio signal by a DAC (Digital-Analog Converter) 17 and sent to an audio output unit 18 by an internal amplifier and a speaker to reproduce sound. Be done. Also, the PCM data of 2ch selected and output to the external output system is sent to the external output interface (I / F) 19. The external output interface 19 includes an HDMI output terminal, an S / PDIF optical digital audio output terminal, and an S / PDIF coaxial digital audio output terminal, and the external AV amplifier 2 and the HDMI cable, the S / PDIF optical digital cable, and the S / PDIF optical digital cable respectively. The audio asset selected by the audio selection control unit 13 is output to the externally connected AV amplifier 2 which can be connected by a PDIF coaxial digital cable. When the corresponding audio mode information of the externally connected AV amplifier 2 is not obtained, the PCM data of 2 ch from the switching unit 16 is selected and output to the AV amplifier 2.

  Here, when the corresponding audio mode information is obtained when the AV amplifier 2 is connected, the external output interface 19 sends the information to the audio selection control unit 13. When the corresponding audio mode information of the connected AV amplifier 2 is obtained from the external output interface 18, the audio selection control unit 13 registers the information, and when an audio asset of the corresponding audio mode arrives. , Switch to output the audio asset.

  On the other hand, the video stream obtained by the demodulator 11 is sent to the video processor 1A. The video processing unit 1A generates a video signal of a predetermined resolution from the input video stream and sends it to the display device 3 for display. Here, when the corresponding audio mode of the connected AV amplifier 2 can not be registered and set, the audio selection control unit 13 causes the GUI (Graphical User Interface) display unit 1B to perform a display for prompting an input operation of the mode selection. Send instructions to do. In response to the instruction, the GUI display unit 1B causes the display device 3 to display an input operation screen for mode selection through the video processing unit 1A. The user views the screen and performs an operation of selecting the corresponding audio mode of the AV amplifier 2 to the operation input unit 1C, thereby registering and setting the corresponding audio mode of the connected AV amplifier 2 in the audio selection control unit 13. be able to.

  FIG. 2 is a conceptual diagram for explaining a process of connecting an external AV amplifier 2 to the broadcast receiving apparatus 1 and transmitting an audio asset. In FIG. 2, the connection between the receiving device 1 and the external AV amplifier 2 is made by any one of an HDMI cable, an S / PDIF optical digital cable, and an S / PDIF coaxial digital cable.

  First, when the receiving device 1 is in the form of a set top box (STB), the HDMI output terminal of the receiving device 1 and the HDMI input terminal of the external AV amplifier 2 are connected by an HDMI cable. Thereby, the audio signal is transmitted from the receiving device 1 to the external AV amplifier 2 together with the video signal. On the other hand, in the case where the receiving device 1 is in the form of a television, the HDMI output terminal of the external AV amplifier 2 and the output terminal of the external AV amplifier 2 for the purpose of inputting video and audio signals reproduced by the external AV amplifier 2 The HDMI input terminal of the receiving apparatus (TV) 1 is connected by an HDMI cable. In this case, by using the function (HDMI-ARC: audio return channel) that transmits only the audio signal in the direction from the receiving device (television) 1 to the external AV amplifier 2 on the HDMI cable, the audio of the receiving device (television) A signal can be sent to the external AV amplifier 2. Note that the receiver 1 in the form of a television may be equipped with an HDMI output terminal, and may be equipped with a function of transmitting video and audio signals to the HDMI input terminal of the external AV amplifier 2.

  In the case of connection by the S / PDIF optical digital cable or the S / PDIF coaxial digital cable, the digital audio output terminal of the receiver 1 and the optical or coaxial digital audio input terminal of the external AV amplifier 2 are connected.

  Here, in the case of any connection of HDMI, HDMI-ARC and S / PDIF, the audio output from the receiving device 1 to the external AV amplifier 2 is only one audio asset. When a broadcast including a plurality of audio assets is received, the receiving device 1 selects and outputs one audio asset to be output to the external AV amplifier 2.

  Hereinafter, connection with the external AV amplifier 2 and processing required in the receiving device 1 will be described.

As shown in FIG. 2, the receiving apparatus 1 receives a broadcast wave (TLV stream) including a plurality of audio streams (maximum number of audio assets 4). For example, in the advanced wideband CS broadcast, seven types of voice modes can be operated (in the advanced BS digital broadcast, six types are used because the operation of AAC 1.0 ch is not performed). Among them, when broadcasting audio modes other than the three AAC 1.0 ch (not used in advanced BS), AAC 2.0 ch, and AAC 5.1 ch, which requires the receiving device 1 to be reproduced independently, are simultaneous. Audio is broadcast simultaneously. Table 1 shows a combination example of the voice mode and the simultaneous voice in broadcasting.

  The receiving device 1 selects one of the plurality of audio assets to be output and outputs the selected asset to the external AV amplifier 2. The asset to be output may be selected automatically if the user arbitrarily selects it, or if the audio mode compatible with the external AV amplifier 2 is known (previously set on the receiving device 1 side). In this case, as in the case of reproduction in the main body of the reception device 1, an asset with a small component tag value is prioritized. In addition, a function may be provided to decode the audio stream in the receiving device 1 and output the audio stream to the external AV amplifier 2 by linear PCM.

  The audio mode to be output to the outside is a combination according to the corresponding situation of the output destination device.

The audio mode and switching operation in stream output will be described.
First, the system of stream output to S / PDIF and HDMI is defined by IEC60958 and IEC61937. In the case of outputting each voice mode operated in advanced BS broadcast and advanced wideband CS broadcast, it is output according to the definition of Table 2 respectively.

When transmitting AAC 22.2 ch and ALS audio, the bit rate of the signal exceeds the transmittable range at the 48 kHz IEC 609 58 frame rate, so it is necessary to extend the frame rate to more than double speed. Currently, we are preparing for the revision of IEC60958 and IEC61937 corresponding to this.

  As an operation example when outputting a broadcast in which the audio mode changes to the external AV amplifier 2, the receiving device 1 and the external AV amplifier 2 in receiving a broadcast in which the audio mode changes from MPEG4-AAC 2 ch to MPEG 4-ALS 2 ch The operation of is shown in FIG.

  The receiving device 1 receives the asset of AAC 2ch which is the preceding voice (FIG. 3 (a)), and outputs it to the S / PDIF at a frame rate of 48 kHz (FIG. 3 (b)). The external AV amplifier 2 receives this stream, decodes it, and outputs it to the speaker (FIG. 3 (c)). In this state, when the preceding voice asset of the broadcast is stopped (FIG. 3 (a)), the receiving device 1 outputs the NULL data stream to S / PDIF for 50 msec or more according to IEC 60958-1 (FIG. 3 (b)). / Stop output to PDIF. The external AV amplifier 2 discharges the audio stream accumulated in the buffer by this NULL data stream.

  When the receiving device 1 receives the ALS 2ch asset that is the subsequent voice (FIG. 3 (a)), the receiving device 1 changes the S / PDIF frame rate to 96 kHz and outputs the ALS 2ch stream (FIG. b). The external AV amplifier 2 having received such a stream changing on the S / PDIF performs resynchronization processing by the PLL circuit with respect to the change of the frame rate. Thereafter, format detection of the audio stream and switching from AAC to ALS of the audio decoder are performed, and the delay time of the ALS decoding is passed, and the subsequent audio is output from the speaker (FIG. 3 (c)).

  Furthermore, in FIG. 4 and FIG. 5, when the stream in which the audio mode changes in the middle is broadcast in the advanced BS / high-bandwidth CS digital broadcast, the change of the audio mode in the broadcast signal and the S / PDIF from the receiver 1 And the audio data output from the AV amplifier 2.

  FIG. 4 shows the relationship when the audio mode changes from MPEG4-AAC 2 ch to MPEG 4-AAC 5.1 ch. The receiver 1 which has received AAC 2ch from the broadcast signal outputs the AAC 2ch audio stream to the S / PDIF with a transmission clock of 48 kHz (1 × speed). Also, in broadcasting, an MPT for notifying a change of the sound mode is sent out about 100 msec before the sound mode changes.

  When the receiving device 1 sees the contents of the MPT and learns that the audio changes from AAC 2 ch to 5.1 ch, the output of the audio stream to the S / PDIF is stopped. However, since it is known that the subsequent voice is 5.1 ch and can be transmitted with the same 48 kHz transmission clock, the transmission clock continues to be output. Thereafter, when a subsequent AAC 5.1 ch audio stream is received, the stream is output to S / PDIF.

  The AV amplifier 2 receiving such a signal from the S / PDIF outputs the AAC 2ch audio to the speaker while the AAC 2ch audio is being input, and stops the audio output when it enters the no audio section, Next, when an audio signal is input, processing is performed to detect what the audio is, and when it is determined that the AAC is 5.1ch, output is performed to the speaker.

  On the other hand, FIG. 5 shows the case where the audio mode changes from MPEG4-AAC 2 ch to MPEG 4-AAC 22.2 ch. The difference from the case of FIG. 4 is that the MPEG4-AAC 22.2ch can not transmit at a bit rate of 48 kHz for the S / PDIF transmission clock, and the transmission clock needs to be switched to 96 kHz (double speed). .

  The receiving device 1 which has grasped the change of the audio mode by updating the MPT stops the S / PDIF AAC 2ch audio output when knowing that the subsequent audio is MPEG4-AAC 22.2ch which needs transmission at 96 kHz. After that, the output of the 48 kHz transmission clock is also stopped. Thereafter, the voiceless data of the transmission clock of 96 kHz is outputted to the S / PDIF, and when the 22.2 ch voice stream is received, the voice is outputted to the S / PDIF.

  The AV amplifier 2 receiving such a signal from the S / PDIF is synchronized with the receiver 1 at a frequency of 96 kHz by the PLL when the signal of the transmission clock of 96 kHz is received after the signal of AAC 2 ch 48 kHz is disconnected. I do. After the time required for this synchronization (about 200 msec) has elapsed, an audio signal is received, and after knowing that it is AAC 22.2 ch, sound is output to the speaker. As described above, when voice mode changes with different transmission clocks occur, there is a problem that the time required for sound output becomes long. As shown in FIG. 3, the audio mode switching from the MPEG4-AAC 2 ch to the MPEG4-ALS also causes switching with different transmission clock frequencies, so the same problem occurs.

As described in the problem, in the advanced BS broadcasting, the voice mode is expanded. As a result, at the transmission clock frequency defined by the conventional S / PDIF standard, there is a voice mode in which the transmission rate is insufficient and transmission can not be performed. For this reason, S / PDIF standard revision work is performed to extend the S / PDIF standard and enable high-speed transmission. Table 3 shows the relationship between the voice mode and the transmission clock frequency in S / PDIF.

  It is not necessary to receive and output all the audio modes defined in the standard as shown in Table 3 as the AV amplifier (including devices such as a sound bar) 2 compatible with advanced BS broadcasting, and AAC 1ch / 2ch It is possible to commercialize a product corresponding to /5.1ch only. In this case, the transmission clock frequency of S / PDIF only needs to correspond to 48 kHz.

  On the other hand, when the AV amplifier 2 corresponds to MPEG4-AAC 22.2 ch, the transmission clock frequency of the S / PDIF corresponds to both 48 kHz and 96 kHz. When the AV amplifier 2 supports up to MPEG4-ALS 5.1 ch, it is necessary to further cope with the transmission clock frequency of 384 kHz.

In order to convey these distinctions to general consumers in an easy-to-understand manner, the AV amplifier product is classified into three profiles as shown in Table 4 in this embodiment.

  On the other hand, the broadcasting station switches the audio mode of the audio stream during broadcasting and transmits it. For example, the program main part is in the form of MPEG4-AAC 5.1 ch, and the CM part is in the form of MPEG4-AAC 2 ch.

  In advanced BS broadcasting, when such an audio stream is switched, the MPT is updated 100 msec before the switching, and the receiving apparatus 1 is notified in advance that the audio stream is switched.

  When the receiving device (TV) 1 that has received such a broadcast performs sound output with the built-in speaker, the receiving device (TV) 1 first outputs the audio on the preceding side if the switching of the audio mode is known in advance by updating the MPT. To mute the switch, change the setting of the decoder to match the audio mode to the subsequent audio stream, and perform the subsequent audio output to the speaker when the subsequent audio is received.

  On the other hand, when an audio stream is output from the receiving device (TV) 1 to the AV amplifier 2 and the sound is output to the speaker via the AV amplifier 2, as shown in FIG. Output MPEG4-AAC 2ch) to S / PDIF. When switching of the voice mode is detected by the MPT update, the output of the preceding voice to the S / PDIF is stopped. However, the S / PDIF transmission clock continues to be at 48 kHz. When the subsequent voice (MPEG4-AAC 5.1 ch) is received, the receiver (TV) 1 outputs the stream of the subsequent voice to the S / PDIF.

  Here, the S / PDIF has no means for transmitting information other than the audio stream from the receiver (TV) 1 to the AV amplifier 2. Therefore, the AV amplifier 2 checks the content of the received audio stream each time when switching the audio mode, and detects a change from AAC 2 ch to AAC 5.1 ch. For this reason, the subsequent sound is output from the speaker later by a certain amount of time than the point where the stream on S / PDIF is changed to AAC 5.1 ch. This time is a time for the AV amplifier 2 to detect audio mode switching.

  The above example describes the case where the S / PDIF transmission clock frequency changes within the range of transmittable audio modes at 48 kHz, that is, the change from MPEG4-AAC 2ch to MPEG4-AAC 5.1ch. . FIG. 5 shows audio mode switching that requires switching from different transmission clock frequencies, such as MPEG4-AAC 2 ch to MPEG 4-AAC 22.2 ch.

  The receiver (TV) 1 that has received the voice of MPEG4-AAC2ch that is the preceding voice transmits the stream of AAC2ch at a transmission clock frequency of 48 kHz when outputting the audio stream to the S / PDIF. The receiving apparatus (TV) 1 which has grasped that the subsequent audio is MPEG4-AAC 22.2 ch by the update of the MPT first stops the transmission of the preceding audio. Next, since the subsequent voice is a voice mode that can not be transmitted without a clock of 96 kHz, the transmission clock of 48 kHz is also stopped, and then the transmission clock of 96 kHz is output. After that, when the subsequent audio is received, the audio stream of MPEG4-AAC 22.2 ch is transmitted with a clock of 96 kHz.

  On the other hand, from the viewpoint of the AV amplifier 2 that receives this audio stream, the audio stream is first stopped while the audio of MPEG4-AAC 2ch 48 kHz which is the preceding audio is being output, and then the transmission clock of 48 kHz is also stopped. Subsequently, a 96 kHz transmission clock is input via the S / PDIF. Since the frequency of the transmission clock for communication has changed, synchronization processing of the transmission clocks of the receiver (TV) 1 and the AV amplifier 2 is performed by the PLL circuit.

  When the communication channel between the receiving device (TV) 1 and the AV amplifier 2 can be synchronized, the audio stream can be received again via the S / PDIF, the audio mode of the received audio stream is detected, and to the speaker The operation of emitting the sound of is performed. It is assumed that the time taken for the synchronization process by this PLL (PLL lock time) takes a relatively long time of about 200 msec. Therefore, there arises a problem that the leading portion of the subsequent voice is missing.

  In order to avoid this problem, to which transmission clock frequency the AV amplifier 2 connected to the receiving device (TV) 1 can support, that is, to which profile in Table 4 the receiving device (TV) 1 belongs. Whether the AV amplifier is connected is stored as the connection mode of the profile.

  When an HDMI cable is used for connection between the receiving device (TV) 1 and the AV amplifier 2, from HDMI's Extended Display Identification Data (EDID) or High Definition Multimedia Interface-Consumer Electronics Control (HDC-CEC) Based on the information that can be acquired, the receiving device (TV) 1 determines which profile the AV amplifier 2 belongs to, and stores the connection mode of the profile. For example, when an AV amplifier capable of supporting only MPEG2-AAC 2ch / 5.1ch is connected, the receiver (TV) 1 stores and sets "Profile-A connection mode". When an AV amplifier capable of supporting MPEG2-AAC 2ch / 5.1ch / 22.2ch is connected, the receiver (TV) 1 stores and sets "Profile-B connection mode".

  On the other hand, when the connection between the receiving apparatus (TV) 1 and the AV amplifier 2 is an S / PDIF optical cable or a coaxial cable, the receiving apparatus (TV) 1 can not obtain information on the AV amplifier 2. Therefore, a menu for inputting “profile of connected AV amplifier” is created by the GUI of the receiving device (TV) 1, and the user is made to input.

  By providing the receiving device (TV) 1 with a function of storing and setting a “profile connection mode” indicating which profile the AV amplifier 2 connected to the receiving device (TV) 1 belongs to, the receiving device (TV) 1 The audio stream output to S / PDIF is as shown in FIG. 6 and FIG. 6 and 7 show signals output from the receiver (TV) 1 for each mode to the S / PDIF when a broadcast in which an audio stream changes from MPEG4-AAC 2 ch to MPEG 4-AAC 22.2 ch is received. FIG.

  FIG. 6 is a diagram when a Profile-B AV amplifier capable of handling AAC 22.2 ch is connected. The receiver (TV) 1 set to “Profile-B connection mode” is 96 kHz even if it is an AAC 2 channel stream that is originally sufficient for 48 kHz when outputting MPEG 4 AAC 2 channel audio to S / PDIF. Output to S / PDIF. Thereafter, even if audio switching to MPEG4-AAC 22.2 ch occurs, it is possible to switch only the audio stream with the transmission clock remaining at 96 kHz. As a result, the PLL lock time as shown in FIG. 5 becomes unnecessary, and it is possible to reduce the loss of sound at the switching point from AAC 2 ch to 22.2 ch.

  On the other hand, FIG. 7 is a diagram when the Profile-A AV amplifier which can not handle MPEG4-AAC 22.2 ch is connected. The receiver (TV) 1 set in “Profile-A connection mode” can not use any clock other than 48 kHz when outputting MPEG4-AAC 2ch audio to S / PDIF. Since it is an output, the transmission clock of S / PDIF is set to 48 kHz and output.

  In the case of advanced BS broadcasting, the audio decoder that the receiving apparatus is required and must have is only MPEG4-AAC 1ch / 2ch / 5.1ch, and the other is optional. For this reason, when broadcasting AAC 22.2 ch or MPEG 4-ALS audio, the audio of AAC 2 ch or 5.1 ch is always broadcast as a simulcast.

  The Profile-A AV amplifier can not handle AAC 22.2ch audio. For this reason, the receiver (TV) 1 that recognizes that audio switching to MPEG4-AAC 22.2 ch occurs due to MPT update is simultaneous broadcast audio of AAC 2 ch or 5.1 ch that can be handled by the AV amplifier of Profile-A. The broadcast signal is searched, and the voice is output to the S / PDIF with the transmission clock kept at 48 kHz. In this case, since the AV amplifier 2 receives a stream in which the mode does not change with both the preceding voice and the subsequent voice as in MPEG4-AAC 2ch, the subsequent voice can be output without requiring the voice mode detection time.

  As described above, when the connection between the receiving apparatus (TV) 1 and the AV amplifier 2 is an S / PDIF optical cable or a coaxial cable, the receiving apparatus (TV) 1 can advance in advance the audio mode that can be received by the AV amplifier 2. Although it is not possible to automatically understand, it is necessary to output to the AV amplifier 2 a stream from which sound can be reproduced by allowing the user to register in advance in the GUI that "Profile-A connection mode" is set. Can.

  The MPEG4-AAC 22.2 ch of this embodiment can be read as the MPEG 4-ALS 2 ch. When handling MPEG4-ALS 5.1ch, a third profile and mode called Profile-C will be added.

  The above control process is performed by the voice selection control unit 13 shown in FIG. Specific processing procedures in the voice selection control unit 13 are shown in FIG. 8 and FIG.

  FIG. 8 is a flowchart showing the procedure of the voice mode registration setting process. First, in the connection of the external AV amplifier 2, it is judged whether or not it is a connection by the HDMI cable (step S1), and if it is the HDMI connection (NO), the user selects the profiles A to C by the GUI display (step S2). Is performed (step S3), and the selected profile is registered and set (step S4).

  In step S1, in the case of HDMI connection (YES), it is determined whether the EDID is available through the HDMI cable (step S5), and if the EDID is available (YES), the EDID is obtained (step S6) The physical address of the device is specified from the EDID to determine a compatible profile (step S7), and the process proceeds to step S4 to register and set the profile.

  In step S5, if the EDID is not obtained (NO), an HDMI-CEC command is obtained (step S8), and a compatible profile is determined from the HDMI-CEC command (step S9), and in step S4. Migrate and register the profile.

  FIG. 9 is a flow chart showing the procedure of processing after voice mode registration setting at the time of S / PDIF connection as an example. First, when MPT is detected during reception of an audio stream (steps S11 and S12), the registration profile of the AV amplifier 2 is determined (step S13), and if the profile connection mode is A, the clock speed is set to 48 kHz (step S14). If it is B, the clock speed is set to 96 kHz (step S15). If it is C, the clock speed is set to 384 kHz (step S16).

  Here, it is determined whether or not the double speed mode (96 kHz, 384 kHz) is selected in the above clock setting (step S17), and if it is not double speed mode, it is converted to voice mode of 1 double speed 48 kHz (step S18). To the S / PDIF in the corresponding voice mode (step S19).

  As described above, in the broadcast receiving apparatus according to the present embodiment, the connected audio device does not correspond to the audio mode of the profile of the double-speed mode when the audio of the non-double-speed mode and the audio of the double-speed mode are mixed and broadcast. In this case, when switching to voice in the double speed mode, it can be converted to voice in the non double speed mode and output.

  In addition, when the connected audio device is also compatible with the double-speed mode, the audio mode of the corresponding profile is grasped in advance and the clock is set not to be changed before and after the audio mode switching. The head loss of the output voice can be extremely reduced.

  In addition, even when it is not possible to grasp in advance the audio mode correspondence situation in the AV amplifier, the user can select the audio to be output by designating and inputting the mode by the GUI.

  While certain embodiments of the present invention have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and the gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

  DESCRIPTION OF SYMBOLS 1 ... Broadcast receiving apparatus, 11 ... Demodulation part, 12 ... TLV / MMT separation part, 13 ... Sound selection control part, 14 ... Decoder, 15 ... DMIX part, 16 ... Switching part, 17 ... DAC, 18 ... Sound output part, 19: external output interface, 1A: video processing unit, 1B: GUI display unit, 1C: operation input unit, 2: AV amplifier, 3: display device.

Claims (18)

A broadcast receiving apparatus that receives a broadcast in which a first audio signal and a second audio signal are selectively transmitted, and outputs the received audio signal to an externally connected audio device,
The first transmission clock frequency and the second transmission clock frequency are the transmission clock frequency of the audio signal transmission with the externally connected audio device, and the first audio signal has the first transmission clock frequency and the second transmission clock frequency. If transmission is possible at both of the transmission clock frequencies and the second audio signal can be transmitted only at the second transmission clock frequency,
The audio device is classified into a first mode corresponding only to the first transmission clock frequency, and a second mode corresponding to both the first transmission clock frequency and the second transmission clock frequency, When the connected audio device is in the first mode and the received audio signal is the first audio signal, the audio signal is output according to the first transmission clock frequency, and the connected audio device In the second mode, when the received voice signal is the first voice signal, the control unit determines the transmission clock frequency to output the voice signal according to the second transmission clock frequency. The broadcast receiving apparatus provided.   The broadcast receiving apparatus according to claim 1, wherein the first mode is a mode in which the transmission clock frequency of the output interface is available only at 48 kHz, and the second mode is a mode in which both 48 kHz and 96 kHz are available.   The broadcast receiving apparatus according to claim 1, further comprising a graphical user interface (GUI) processing unit for the user to select the first mode and the second mode.   When the control unit uses an HDMI (High Definition Multimedia Interface) for connection with the audio device, the control unit specifies an Extended Display Identification Data (EDID) defined by the HDMI or an HDMI-CEC (High Definition Multimedia Interface-Consumer Electronics Control). 2. The broadcast receiving apparatus according to claim 1, wherein it is automatically determined and switched from the information of (1) whether to adopt the first mode or the second mode.   The broadcast according to claim 4, wherein the control unit adopts the second mode when it is detected that the audio device can handle MPEG4-ALS from the information of the HDMI EDID or HDMI-CEC. Receiver.   The controller according to claim 4, wherein the control unit adopts the second mode when it is detected that the audio device can handle the MPEG4-AAC 22.2 ch from the information of the HDMI EDID or HDMI-CEC. Broadcast receiver. When the audio signal received from the broadcast is a first audio signal that can be transmitted at any of the first transmission clock frequency and the second transmission clock frequency, the control unit is configured to: Determining the transmission clock frequency to output the received first audio signal to the audio device using the second transmission clock frequency when a mode is selected;
The first mode is selected when the second mode is selected, when the second mode can not be transmitted except for the second transmission clock frequency after the first mode is broadcast. 2. The broadcast receiving apparatus according to claim 1, wherein the transmission clock frequency is determined so that the second audio signal is also output to the audio device at the second transmission clock frequency following the audio signal of.   When the audio signal received from the broadcast is a second audio signal that can not be transmitted at frequencies other than the second transmission clock frequency, the control unit receives from the broadcast when the first mode is selected. 2. The broadcast receiving apparatus according to claim 1, wherein another audio signal that can be transmitted at the first transmission clock frequency in the selected signal is selected and output to the audio device at the first transmission clock frequency.   In addition to a first mode in which only the first transmission clock frequency can be used, and a second mode in which the first and second transmission clock frequencies can be used, the control unit further includes first, second and second modes. When the transmission clock frequency of 3 has the available third mode, the relationship between the first mode and the second mode is the relationship between the first mode and the third mode, the second The broadcast receiving apparatus according to claim 1, which is applied to the relationship between the mode of and the third mode. A broadcast receiving method for receiving a broadcast in which a first audio signal and a second audio signal are selectively transmitted, and outputting the received audio signal to an externally connected audio device,
The first transmission clock frequency and the second transmission clock frequency are the transmission clock frequency of the audio signal transmission with the externally connected audio device, and the first audio signal has the first transmission clock frequency and the second transmission clock frequency. If transmission is possible at both of the transmission clock frequencies and the second audio signal can be transmitted only at the second transmission clock frequency,
The audio device is classified into a first mode corresponding only to the first transmission clock frequency, and a second mode corresponding to both the first transmission clock frequency and the second transmission clock frequency, When the connected audio device is in the first mode and the received audio signal is the first audio signal, the audio signal is output according to the first transmission clock frequency, and the connected audio device A broadcast receiving method for determining the transmission clock frequency to output the audio signal according to a second transmission clock frequency when the received audio signal is a first audio signal in a second mode;   The broadcast receiving method according to claim 10, wherein the first mode is a mode in which the transmission clock frequency of the output interface is available only at 48 kHz, and the second mode is a mode in which both 48 kHz and 96 kHz are available.   11. The broadcast receiving method according to claim 10, further comprising selecting the first mode and the second mode by a user's designated operation input.   When high definition multimedia interface (HDMI) is used for connection with the audio device, the information from extended display identification data (EDID) or high definition multimedia interface-consumer electronics control (HDCE) defined by the HDMI is used. The broadcast receiving method according to claim 10, wherein it is automatically determined and switched whether to adopt the first mode or the second mode.   The broadcast receiving method according to claim 13, wherein the second mode is adopted when it is detected that the audio device can handle MPEG4-ALS from the information of the HDMI EDID or HDMI-CEC.   The broadcast receiving method according to claim 13, wherein the second mode is adopted when it is detected from the information of the HDMI EDID or HDMI-CEC that the audio device can handle the MPEG4-AAC 22.2 ch. The second mode is selected when the audio signal received from the broadcast is a first audio signal that can be transmitted at any of the first transmission clock frequency and the second transmission clock frequency. Determining the transmission clock frequency to output the received first audio signal to the audio device using the second transmission clock frequency,
The first mode is selected when the second mode is selected, when the second mode can not be transmitted except for the second transmission clock frequency after the first mode is broadcast. 11. The broadcast receiving method according to claim 10, wherein the transmission clock frequency is determined such that the second audio stream is also output to the audio device at the second transmission clock frequency following the audio signal of.   When the audio signal received from the broadcast is a second audio signal that can not be transmitted other than the second transmission clock frequency, the above-mentioned signal in the signal received from the broadcast is selected when the first mode is selected. 11. The broadcast receiving method according to claim 10, wherein another audio signal that can be transmitted at a first transmission clock frequency is selected and output to the audio device at the first transmission clock frequency.   In addition to a first mode in which only the first transmission clock frequency is available, a second mode in which the first and second transmission clock frequencies are available, first, second and third transmission clock frequencies And the third mode, wherein the relationship between the first mode and the second mode is the relationship between the first mode and the third mode, the second mode and the third mode. The broadcast receiving method according to claim 10, which is applied to the relationship with the mode of.

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