JP2005151308A - Receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To decode and reproduce voices of all displayed programs with a predetermined or less throughput by means of a microprocessor when a plurality of screens are displayed. <P>SOLUTION: A receiver can receive a plurality of television broadcast programs and display video images of the plurality of programs at a time on the same screen. The number of the broadcast programs to be displayed on the same screen and display screen sizes of the respective programs are specified. The number of channels of voice signals to be decoded for each program is determined based on the specified number of the programs and the sizes, and the voice signals are decoded depending on the determined channels. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a receiving apparatus, and more particularly to an apparatus that displays a plurality of screens simultaneously, that is, a so-called multi-screen display apparatus that reproduces sound of all displayed screens with a constant processing amount.

  In recent years, distribution of television programs by BS broadcasting and CS broadcasting has been performed, and the number of channels has been rapidly increasing. For this reason, there has been proposed a digital television capable of so-called multi-screen display, in which a plurality of programs are input and decoded from a plurality of tuners and a plurality of screens are simultaneously displayed.

  When multi-screen display is performed, the sound of the main screen, which is generally displayed with the largest sound, is reproduced. As disclosed in Patent Document 1, it has been proposed to detect a line of sight and decode the sound of the screen that the user is viewing, but basically the sound of one screen is reproduced. In this case, the sound other than the main screen is not reproduced and can only be used for auxiliary purposes.

As a proposal to simultaneously reproduce the sound of a plurality of screens, the main screen is output by a television speaker as in Patent Document 2 and the sub screen is output to headphones, and both the main screen and the sub screen are disclosed in Patent Document 3. It has been proposed to synthesize monaural sound and output the sound of the main screen from the right speaker and the sound of the sub-screen from the left speaker. These technologies are for conventional analog broadcasting, but can be applied to digital broadcasting as they are.
JP 2000-278626 A JP-A-9-9166 Japanese Patent Laid-Open No. 9-322094

  However, when the technique of the above-mentioned patent document is applied to the reception of digital broadcasting, it is necessary to decode all the sounds on a plurality of screens. In the case of digital broadcasting, since the audio is compressed and takes more time to decode than the conventional analog broadcasting, and the number of channels is a maximum of 6 channels, it is not efficient to decode all the audio. In particular, when audio processing is performed by software using a microprocessor at the same time as other processing, if all channels are decoded, the audio processing may press on other processing, or in real time. May not be in time for playback.

  To solve the above-mentioned problems of the present invention and to decode and reproduce the audio of all displayed programs using a microprocessor with a certain processing amount or less when displaying multiple screens. Objective.

  The present invention is a receiving device that can receive a plurality of television broadcast programs and simultaneously display the videos of the plurality of broadcast programs on the same screen, and the number of broadcast programs to be displayed on the same screen and each Setting means for setting a display screen size of the broadcast program, a video decoding unit for decoding the encoded video signals related to the plurality of broadcast programs, and a decoding of the encoded audio signal related to the plurality of broadcast programs An audio decoding unit, display control means for synthesizing the video signals of the plurality of broadcast programs decoded by the video decoding unit and outputting them to a display device, and the audio signal decoded by the audio decoding unit to an audio output device Based on the audio output means to output, the number of broadcast programs set by the setting means and the display screen size, the number of channels of the audio signal to be decoded for each broadcast program is determined and determined. And a control means for controlling the audio decoding unit to decode an audio signal according to the channel.

  Even when a plurality of programs are displayed on the same screen, the sound of all the displayed programs can be decoded and reproduced using a microprocessor with a predetermined processing amount or less.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a receiving apparatus according to the first embodiment of the present invention.

  In FIG. 1, 101 is an antenna for receiving terrestrial broadcasting, BS broadcasting, CS broadcasting, etc., 102 is a tuner, 103 is a microprocessor for executing a program, 104 is a TS demultiplexer, 105 is a video decoder, and 106 is an audio decoder. , 107 is an image composition unit that synthesizes a plurality of images, 108 is an audio placement unit that determines the output position of sound on multiple screens, 109 is an input unit such as a remote controller and operation panel, 110 is a system control unit, and 111 is a video A display control unit that controls display of the signal, 112 is a D / A converter that converts a digital audio signal into analog information, 113 is a display device, and 114 is an audio output device.

  First, the operation of the digital television apparatus in normal one program viewing will be described. In normal viewing, the viewer operates the input unit 109 to instruct the tuner 102 to select a channel and select a program. The tuner 102 detects a TS (Transport Stream) including the channel of the selected program from the signals received from the antenna 101, and inputs it to the microprocessor 103. The system control unit 110 recognizes that viewing of one program has started from the operation of the input unit 109, instructs the microprocessor 103 to start decoding of one program, and instructs the audio decoder 106 to perform audio signals for all six channels. To decode. On the microprocessor 103, the demultiplexer 104 first demultiplexes the TS signal, and inputs the video signal of the selected program to the video decoder 105 and the audio signal to the audio decoder 106, respectively. In accordance with ARIB (Association of Radio Industries and Businesses) standards, the video signal is MPEG2 and the audio signal is AAC. The video signal decoded by the video decoder 105 is sent to the image synthesizer 107, but since it is output on one screen, the image synthesizer 107 sends the signal to the display controller 111 without any particular action, and the image for one screen is displayed on the display device. 113 is displayed. The audio decoder 106 receives an input from the system control unit 110, decodes all six channels, and outputs the decoded data to the audio placement unit 108. Since the voice placement unit 108 also has only one screen of voice, it does not operate and outputs the voice signal to the D / A converter 112 as it is. The D / A converter 112 converts the audio signal into an analog signal and outputs it from the audio output device 114.

  In the case of single screen display, the normal decoding process is not changed. In a digital television having such a configuration, the microprocessor is required to have a processing capacity capable of at least video decoding for one screen and audio decoding for six channels.

  Next, in the first embodiment, a case where two programs are received simultaneously and displayed on two screens will be described.

  FIG. 2 shows a block diagram when two programs are received simultaneously. The basic operation is the same as in FIG. 1, but a first tuner 115 and a second tuner 116 are prepared as tuner sections in order to receive two programs simultaneously. The system control unit 110 recognizes from the input unit 109 that two screens are simultaneously displayed, and instructs the microprocessor 103 to start two screen decoding. The microprocessor 103 receives an instruction from the system control unit 110 and receives the first demultiplexer 117 and the second demultiplexer 118, the first video decoder 119 and the second video decoder 121, the first audio decoder 120 and the first demultiplexer 118. The second audio decoder 122 is operated to decode the inputs from the first tuner 115 and the second tuner 116, respectively. Further, the system control unit 110 obtains the size of two screens from the input unit 109, determines that the number of channels to be decoded by the first audio decoder 120 and the second audio decoder 122 is a total of six channels, Notify the decoder. A method for determining the number of channels will be described later. The image signals decoded by the two video decoders are synthesized by the image synthesis unit 107 and output to the image display unit 113. Similarly, the signals decoded by the two audio decoders are synthesized by the voice synthesis unit 108 and output to the D / A converter 112.

  Since the video composition is not the gist of the present invention, it will be omitted.

  Next, the audio signal decoding process during two-screen display will be described.

  When the user operates the input unit 109 to perform multi-screen display, the system control unit 110 recognizes the ratio of the number and size of screens to be displayed from the input content. In the case of multi-screen display, it is normal to select several screen division patterns. For example, there is a pattern as shown in FIG. In this embodiment, it is assumed that the system has the pattern of FIG. The system control unit 110 notifies the first audio decoder 120 and the second audio decoder 122 of the number of channels to be decoded based on the ratio between the number of screens and the size. The number of channels to be decoded is determined so that the sum of all audio decoders is 6 channels. As a result, the processing amount of all audio decoders can be kept below a certain level, and it is possible to prevent the processor from performing processing more than necessary for an output device having only six channels.

  In the case of the pattern of FIG. 3, the number of channels to be decoded is determined in advance as shown in FIG.

  That is, when the size of the two screens is equal as shown in FIG. 3A, the sound of either screen is decoded by three channels, and when there is a difference in the screen size as shown in FIG. The screen (main screen) is 4-channel decoding, and the smaller screen (sub-screen) is 2-channel decoding.

  The first and second audio decoders 120 and 122 receive an instruction on the number of channels to be decoded from the system control unit 110 and decode the audio signal. Which channel is to be decoded is determined in advance according to the number of channels to be decoded. For example, as shown in FIG. Here, FC is a front center speaker, FL and FR are front left speakers, front right speakers, RL and RR are rear left speakers, rear right speakers, and LFE are woofers, respectively. An example of the arrangement of each speaker is shown in FIG.

  It is not difficult to distinguish which channel is output to which speaker in the input bit stream. According to the AAC standard, the arrangement in the bit stream and the arrangement of the speakers are basically determined by the number of channels, as shown in FIG. Here, SCE is an abbreviation for Single Channel Element, CPE is an abbreviation for Channel Pair Element, and LFE is an abbreviation for Low Frequency Enhancement. Therefore, if only 2 channels are decoded even if the input is 6 channels, it is only necessary to decode the audio that should be placed in the FL and FR according to FIG. 4, so the first CCE is not decoded and the next CPE is decoded. The subsequent streams can be ignored. The same applies when the number of channels is different. When PCE (Program Config Element) exists in the stream, the channel indicated by the PCE may be decoded.

  In this way, it is possible to decode the sound of a plurality of screens so that it can be recognized to some extent by the processing amount for 6 channels.

  The decoded audio is arranged by the audio arrangement unit 108. The audio placement unit 108 receives the audio output from each decoder, and outputs the output of the first audio decoder 120 as it is to the speaker to be originally output. Thereafter, the output of the second audio decoder 122 is assigned to an empty speaker. The actual data arrangement depends on the specifications of the D / A converter. FIG. 7 shows a connector for connecting the actual audio output device 114. FIG. 7 shows the case of main screen 4 audio and sub screen 2 audio. The main screen outputs sound from the FC, FL, FR, and RL connectors, and the sub screen outputs sound from the RR and LFE. A user who views the sub-screen can view it without being influenced by the main screen by switching the speaker to headphones. If the audio sampling frequency differs between the first audio decoder 120 and the second audio decoder 122, the audio arrangement unit appropriately thins out the data with the higher sampling frequency and outputs it in accordance with the lower sampling frequency. To do. Alternatively, some interpolation method may be used to output in accordance with the higher sampling frequency.

  In the case as shown in FIG. 3A, three-channel decoding is performed for both screens, but when the main screen sound and the sub-screen sound are heard separately, one of them often becomes headphones. In this case, with respect to the sound of either one of the screens, the sound is mixed down after stereo decoding and output in stereo.

  In this embodiment, the demultiplexer, the video decoder, and the audio decoder are operated by the microprocessor, but the present invention is not limited to this. If the audio decoder is operating on the microprocessor, it can be used.

  In the present embodiment, the input sound is 5.1 channels for any screen. However, the present invention is not limited to this, and any channel can be used if it is 5.1 channels or less. Although it can be applied with more than 5.1 channels, the ARIB standard does not make much sense because digital television broadcasting only broadcasts up to 5.1 channels.

  In this embodiment, the input is AAC compressed audio, but it may be uncompressed audio or an analog signal from an external device or the like. In this case, it is necessary for the user to input in advance how many channels are input from the external device.

  In this embodiment, the upper limit of the number of audio channels to be decoded is set to 6. This is because there are usually only 6 output devices, and the number of audio channels is a system having 6 or more outputs. The present invention can be applied even if the upper limit of the number is 6 or more.

  In the present embodiment, the case of two-screen display has been described, but the present invention is not limited to this. For example, in the case of simultaneous display of three screens, a screen pattern as shown in FIG. 8 can be considered, and the same effect can be obtained by performing 2-channel decoding for each screen. The present invention can cope with the case where the number of screens is six. If there are six or more output devices, the number of screens that can output sound can be further increased.

  Next, a second embodiment will be described with reference to the drawings.

  FIG. 9 is a block diagram showing a configuration of a receiving apparatus according to the second embodiment. In addition, the same code | symbol is attached | subjected about what performs the same operation | movement as 1st embodiment, and description is abbreviate | omitted.

  In FIG. 9, 201 recognizes the number of screens from user input, displays a screen for prompting input of a speaker to be used on each screen on the monitor, and displays the first audio decoder 120 and the second audio decoder 122 according to the user input. A system control unit 202 that notifies a channel to be decoded is a display control unit 202 that controls display of a normal screen and an input screen from the system control unit 201.

  Unlike the first embodiment, this embodiment is characterized in that the number of decoding channels and output speakers are determined by the user without automatically determining the number of decoding channels based on the number of screens and the screen size. .

  First, when the user operates the input unit 109 to display a plurality of screens, the system control unit 201 sends a screen as shown in FIG. 10 to the display control unit 202 to prompt the user to input. Although all the screens may be input or only the main screen may be input, the total number of channels to be decoded on all screens must be six. The user determines the number of channels to be decoded on each screen and the output speaker according to the instructions on the screen. The system control unit 201 instructs the first and second audio decoders 120 and 122 on the channel to be decoded based on the result. The audio decoders 120 and 122 decode the indicated channel as in the first embodiment. The audio arrangement unit 108 arranges the decoded audio so as to correspond to the user input, and outputs it to the D / A converter 112. Similarly to the first embodiment, when the sampling frequencies of the first audio decoder 120 and the second audio decoder 122 are different, the audio placement unit 108 performs processing for matching the sampling frequencies.

  In this embodiment, since the user can determine the channel to be decoded and the output speaker, audio output can be performed more in line with the user's intention, but there is also a disadvantage that the work of the user increases.

  Note that the present embodiment and the first embodiment may be combined so that the user can determine only when the user desires.

  Also in this embodiment, the present invention can be used as long as the audio decoder is operating on the microprocessor, as in the first embodiment.

  Also in this embodiment, as in the first embodiment, the present invention can be used as long as the input voice is 5.1 channels or less.

  Also in this embodiment, as in the first embodiment, the input may be uncompressed audio or an analog signal from an external device or the like.

  Also in this embodiment, as in the first embodiment, if the system has 6 or more outputs, the upper limit of the number of voice channels can be applied to 6 or more.

  Also in this embodiment, as in the first embodiment, if there are six or more output devices, the number of screens that can output sound can be increased.

It is a block diagram which shows 1st embodiment of the audio | voice reproduction apparatus which concerns on this invention. It is a block diagram which shows the operation | movement at the time of displaying two screens simultaneously in 1st embodiment. It is a figure explaining the operation | movement which determines the audio | voice decoding channel number in the case of a two-screen display. It is a figure explaining the correspondence of the channel number which the audio decoder decodes, and the channel which decodes. It is a name and arrangement | positioning of each speaker in 6 speaker system. It is a figure explaining the correspondence of the number of channels, a bit stream structure, and an output speaker in an AAC format. It is a figure explaining the output destination of an audio | voice. It is a figure explaining the operation | movement which determines the channel number of the audio | voice to decode in the case of a three-screen display. It is a block diagram which shows 2nd embodiment. It is a figure of the screen which prompts the user to select the number of audio channels to be decoded and the output speaker in the case of two-screen display.

Claims (5)

A receiving device capable of receiving a plurality of television broadcast programs and simultaneously displaying images of the plurality of broadcast programs on the same screen,
Setting means for setting the number of broadcast programs to be displayed on the same screen and the display screen size of each broadcast program;
A video decoding unit for decoding encoded video signals related to the plurality of broadcast programs;
An audio decoding unit for decoding encoded audio signals related to the plurality of broadcast programs;
Display control means for combining the video signals of the plurality of broadcast programs decoded by the video decoding unit and outputting them to a display device;
Audio output means for outputting the audio signal decoded by the audio decoding unit to an audio output device;
Based on the number of broadcast programs set by the setting means and the display screen size, the number of channels of the audio signal to be decoded is determined for each broadcast program, and the audio signal is decoded according to the determined channel. And a control unit that controls the speech decoding unit.   The control means determines the number of channels of the audio signal to be decoded so that the total number of channels of the audio signals of the plurality of broadcast programs to be decoded by the audio decoding unit does not exceed a predetermined number. The receiving device according to claim 1.   The control means determines the number of channels of the audio signal to be decoded so that the total number of channels of the audio signals of the plurality of broadcast programs to be decoded by the audio decoding unit does not exceed the processing capability of the audio decoding unit. The receiving apparatus according to claim 1.   2. The receiving apparatus according to claim 1, wherein the setting unit selects one of a plurality of predetermined combinations of the number of broadcast programs to be displayed on the same screen and a display screen size. 2. The receiving apparatus according to claim 1, wherein the setting unit arbitrarily sets the number of broadcast programs to be displayed on the same screen and a display screen size.

Images