JP4270136B2 - Video / audio receiver and television receiver - Google Patents

Description

  The present invention is a television receiver for displaying video and audio when information such as video and audio is input, a recording device such as a VTR and a DVD for recording video and audio, and re-outputting video and audio. The present invention relates to a video / audio receiving device such as a switcher.

  In the field of television broadcasting and devices for recording and reproducing the same, and in the field of package media such as movie software, digital broadcasting has started, and broadcast receiving devices (hereinafter referred to as STB; set-top-box) corresponding thereto, Digital recording / reproducing devices and HD (High Definition) compatible display devices are on the market. Package software used in playback devices will appear in the near future.

  As is well known, the information signal is subjected to processing such as data amount compression and time-division multiplexing in the course of transmission or recording / reproduction, but these are restored by the STB. Accordingly, at least video information is generally given to the display device in baseband even when it is delivered digitally.

  In a display device such as a television receiver, a broadcast signal and a reproduction signal such as a hard disk recorder / DVD (Digital Versatile Disc) / digital VTR are input via the STB. For this reason, a standard for passing these information signals to and from the STB must be determined.

  In North America, a standard called EIA / CEA861 was issued in January 2000 as a digital video baseband transmission standard for display devices for this purpose. Here, DVI 1.0 (Digital Visual Interface version 1.0), which is a connection standard between the main body of a PC (Personal Computer) and a display device, is used. The connection method between the main body of the PC and the display device is described in, for example, Japanese Patent Application Laid-Open No. 61-290529 or the digital monitor interface standard (JEIDA-59-1999) established by the Japan Electronics Industry Promotion Association. Mainly, the video information transmission method is defined in detail. In this case, the voice information is sent through another connection line. The audio information may be in either analog or digital format, and the other connection line may be any one of analog cable, digital coaxial cable, digital optical cable, and the like.

  However, considering usability, it is better to be able to transmit both video and audio over a set of cables. Therefore, various methods have been proposed for this purpose, such as superimposing a digital audio signal during a vertical or horizontal blanking period of a video signal.

  Therefore, a device having two interfaces, a system for transmitting a digital audio signal superimposed on a digital video signal and a system for transmitting an audio signal (either analog or digital format) independently of the video signal, is provided. There is a possibility of appearing. In the case of such a device, the user manually selects either a digital audio signal superimposed on the digital video signal or an audio signal transmitted by a system different from the video signal using a remote controller or the like. Become. Which one to select is determined by whether or not audio playback output is actually obtained from a speaker or the like. In that case, the user confirms from which system the audio is transmitted while performing the switching operation. It must be done and it is inconvenient.

  The object of the present invention has been made in view of the above problems, and the object is to improve the usability by making it possible to obtain an appropriate audio output without manual operation by the user as described above. The object is to provide a video / audio receiving device such as a television receiver. The video / audio receiving device referred to here includes not only television receivers but also video / audio recording / reproducing devices such as VTRs and DVDs, video / audio input switching devices, video / audio distributors, etc. .

In order to achieve the above object , the present invention provides:
A first input unit to which a first audio signal superimposed on the video signal is input, and a second input unit to which a second audio signal not superimposed on the video signal is input separately from the first audio signal When the audio playback, as an audio signal to be used for recording or output, a second sound input to the first audio signal or said second input to be input to the first input A switch for selecting one of the signals, an audio switching control circuit for determining whether or not the first audio signal is superimposed on the video signal, and the second audio signal at the second input unit. A sub-voice evaluation unit that determines whether the input is performed, and an OSD unit for displaying a message on the screen ,
The voice switching control circuit is
Controlling the switch to select the first audio signal when the first audio signal is superimposed on the video signal and the error rate of the first audio signal is smaller than a threshold ; When the first audio signal is not superimposed on the video signal, the switch is controlled to select the second audio signal, and the first audio signal is superimposed on the video signal. , When the error rate of the first audio signal is larger than a threshold, and when the sub audio evaluation unit determines that the second audio signal is not input to the second input unit, The switch is controlled to select the first audio signal, and the OSD unit is controlled to display a message related to the quality of the first audio signal on the screen.

  The first audio signal and the video signal may be digital signals, and the second audio signal may be an analog signal or a digital signal.

The voice switching control circuit may control the switch so as to supply a second voice signal to a speaker when an error rate of the digital voice signal exceeds a predetermined threshold. Further, when the error rate is larger than the threshold value and the second audio signal is not transmitted, the switch is controlled so as to select the first audio signal .

According to the present invention, since the audio signal is automatically switched, the usability is improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention, wherein 1 is a signal generator, and 2 is a video / audio receiver. Both are connected by at least two interfaces (cables, etc.) indicated by 41 and 42 in the figure. In the signal generator 1, 11 is a video signal source, 12 is an audio signal source, 13 is an audio superimposing circuit, 14 is a data transmission circuit, and 15 is a DAC (Digital Analogue Converter). Among the display devices 2, 21 is a data receiving circuit, 22 is an audio separation circuit, 23 is an adder circuit, 24 is a video display unit, 25 is an audio processing circuit with DAC, 26 is a switch, 27 is a speaker, and 28 is An audio switching control circuit, 29 is an OSD (On Screen Display) circuit, 210 is a sub audio evaluation circuit, 241 is a display recording unit, 242 is a display output, 271 is an audio recording unit, and 272 is an audio output.

  In the present invention, first, whether or not a digital audio signal is superimposed on a video signal is automatically determined so as not to require a troublesome switching operation by the user. In general, the quality of a digital signal transmitted is better than that transmitted in an analog format. If it is superimposed, the digital audio signal superimposed on the video signal is preferentially selected and output. To do. Depending on the result of the determination, the unused audio signal processing circuit may be turned off to save power. However, it is continuously determined whether or not a digital signal is superimposed.

  Furthermore, even with a digital audio signal, when the error rate increases, the quality deteriorates abruptly. Rather, it is preferable to output a signal connected in an analog format. Therefore, not only the presence / absence of the superimposition of the digital audio signal, but if it is present, either one may be selected and output depending on the error rate. Since the signal generator 1 and the display device 2 are assumed to be at a relatively short distance, even when transmitted in digital format, it is normal that error correction is not performed on video information. For voice information with strict specifications, error correction is often performed. Therefore, it is easy to realize the function of monitoring the error rate described above.

  In the future, more devices will be designed on the premise of superimposing digital audio signals on video signals, but even in this case, in order to maintain compatibility with conventional devices, Since the connection is considered to remain, the present invention can be applied.

  Also, it is convenient to issue a message to that effect when the output audio signal is switched, or when there are many errors due to the digital audio signal being superimposed and some sort of abnormality is considered. .

  With particular emphasis on the above matters, the operation will be described with reference to FIG. A digital video signal is generated from the video signal source 11, which is a component of the signal generator 1, and a digital audio signal is generated from the audio signal source 12. When the signal generator 1 is an STB, this is obtained, for example, by receiving a digital broadcast, and may be information reproduced from a hard disk recorder built in the STB. In the case of a DVD, a digital VTR, or the like, it is information reproduced from an attached recording medium, and may be package software, for example.

  The digital audio signal is superimposed on the digital video signal by the audio superimposing circuit 13. There are several possible methods. For example, there is a method of superimposing on a horizontal or vertical blanking period of an image. Since it is not necessary to transmit the video signal during the blanking period, it is conceivable to transmit a digital audio signal using the audio signal as an audio packet instead of the video signal during that period.

  The output of the audio superimposing circuit 13 is given to the data transmitting circuit 14, code-converted as necessary, power amplified, and given to the display device 2 via the interface 42. Further, the output of the previous audio signal source 12 is also given to the DAC 15 to become an analog audio signal, which is given to the video / audio receiving device 2 via the interface 41.

  Next, the operation of the video / audio receiver 2 will be described using the flowchart of FIG. 2 as necessary. The digital video signal input via the interface 42 is given to the data receiving circuit 21. If code conversion for transmission is applied to this, it is decoded here. Further, the signal is supplied to the sound separation circuit 22 where the above-described digital sound signal is separated and input to the sound processing circuit 25 with DAC and the sound switching control circuit 28. When the audio signal is not superimposed, dummy data is given to the audio processing circuit 25 with DAC, and information that the audio is not superimposed is given to the audio switching control circuit 28. Note that the audio separation circuit 22 and the audio switching control circuit 28 are not separated in circuit and may be integrated, but this case is also within the scope of the present invention. On the other hand, the digital video information is given to the adding circuit 23, and after adding the information from the OSD circuit 29 as will be described later, it is inputted to the display unit 24 and displayed. If there is a display recording unit 241, video is recorded there, and if there is a display output unit 242, video is output. The operation of the sound separation circuit 22 naturally varies depending on the method of multiplexing the digital sound signal. For example, if it is superimposed on the horizontal or vertical blanking of the video, it is separated by looking at the blanking timing.

  Next, the operation of the voice switching control circuit 28 will be described. FIG. 2 is a flowchart showing the operation of the voice switching control circuit 28, which is also used in the description together. In FIG. 2, a start 101 indicates a starting point of a series of operations. First, the audio superimposition determination unit 102 determines whether or not a digital audio signal is superimposed on a video signal. Several methods are known, such as determining from the format information included in the received data, or determining whether the clock of the audio signal is reproduced from the information separated by the audio separation circuit 22. If there is no superimposition of the digital audio signal, it goes down in FIG. 2 as it is to reach 103 and issues a command to the switch 26 to switch the connection in the direction opposite to that shown in the figure. As a result, the audio signal input via the interface 41 without being superimposed on the video signal is supplied to the speaker 27 to reproduce the audio. If there is an audio recording unit 271, audio is recorded here, and if there is an audio output 272, audio is output there.

  At this time, as indicated by reference numeral 104 in FIG. 2, power consumption may be reduced by not supplying power to unused circuit blocks such as the audio processing circuit 25 with DAC. Further, a command may be sent to the OSD circuit 29 to indicate that the audio signal supplied from the interface 41 side is output as a message on the display unit 24 as indicated by 105 in FIG. Of course, the display may be continued for a long time, or may be turned off after being displayed only for a short time. Thereafter, the process returns to the audio superimposition determination unit 102 to continue the determination. The discriminating operation is performed only once for the first time so that the situation can be changed during the process.

  In FIG. 1, an audio signal input via the interface 41 is described as an analog signal, but the present invention is not limited to this. The point is that it is sent through another interface without being superimposed on the video signal, and includes a case where the interface is a digital coaxial cable or digital optical cable and is supplied as a digital audio signal. In that case, the DAC 15 of the signal generator 1 is removed, and the DAC is placed between the interface 41 and the switch 26, or the DAC of the audio processing circuit 25 with the DAC is separated, and the switch 26 and the speaker 27 are separated. Placed.

  A case where the audio switching control circuit 28 determines that the digital audio signal is superimposed will be described below. The process moves from 102 in FIG. 2 to 111 for determining the error rate. Here, the error rate of the digital audio signal input by being superimposed on the video signal is determined. Of course, when there are many errors, the quality may be inferior to that input in analog form. If the error rate is small and a certain level of quality can be expected, go down from the right side of 111 in FIG. 2 and first supply power to the audio processing circuit 25 with DAC at 123 to compress the separated audio signal. If so, it performs decompression processing here to convert it to analog format. At 124, the switch 26 is also commanded and connected in the direction shown. Thereby, the audio signal input in the digital format is given to the speaker 26 to reproduce the audio. Further, a command may be sent to the OSD circuit 29 in 125 to indicate that the audio signal supplied from the interface 42 is being output on the display unit 24 as a message. If there are components in the portion from the interface 41 to the switch 26 in addition to the sub voice evaluation circuit 210, the supply of these power sources may be stopped. Thereafter, the process returns to the sound superimposition determination unit 102 to continue the determination.

  The case where it is determined that the error rate is large at 111 in FIG. 2 will be described below. Starting from the left side of 111, first, at 112, it is determined whether or not there is an audio signal from the interface 41. In FIG. 1, this is performed by the sub voice evaluation circuit 210. In many cases, this is given in analog form, but it may be a digital audio signal given without being superimposed on the video signal as described above. If there is, the signal goes from 112 to the left side, and the audio signal supplied from the interface 41 side is supplied to the speaker 27 through the same process as described above. This is done particularly when the error rate on the interface 42 side is poor and the audio signal from the interface 41 side is of better quality. If not, the audio signal from the interface 42 is output regardless of the quality. From 112, the power is supplied to the audio processing circuit 25 with DAC at 113, and the separated audio signal is decompressed and converted to an analog format. At 114, the switch 26 is also commanded and connected in the direction shown. Thereby, the audio signal input in the digital format is given to the speaker 26 to reproduce the audio. Further, in 115, a command is issued to the OSD circuit 29, and the audio signal supplied from the interface 42 side is output. However, there is a problem in quality, so check the looseness of the cable connection or replace the cable with a shorter one. The message may be displayed on the display unit 24 as a message. Also in this case, if there are components in the portion from the interface 41 to the switch 26 in addition to the sub voice evaluation circuit 210, the supply of these power sources may be stopped. Thereafter, the process returns to the sound superimposition determination unit 102 to continue the determination.

  The determination of the presence / absence of the voice in 112 of FIG. 2 is not only based on the presence / absence of the text, but also the sub voice evaluation circuit 210 evaluates the quality of the voice signal input from the interface 41, The determination may be made after confirming that the quality is better than the signal. Alternatively, a certain lower limit may be set for the quality of the audio signal input from the interface 41, and if it is inferior to this, the audio signal input from the interface 42 may be output even if the error rate is large.

  If it is determined at 111 that the error rate is large, the switching operation as described above is not performed immediately, but switching may be performed in consideration of the duration of the state. If there is a moment when the error rate deteriorates once in a long time, it is troublesome to switch each time. For example, it is better to switch for the first time when the same state continues for several seconds.

  As described above, it is possible to automatically select and output a digital audio signal that is superimposed on the video signal and a high-quality audio signal that is input separately from the digital audio signal. . If there is no one, the other party is automatically selected, but a warning can be displayed when there is a problem with the quality. In addition, it is possible to know which is selected on the display. Furthermore, the power supply of circuit blocks that are not used can be cut off to save power. There is an effect that the troublesomeness of frequent switching can be eliminated by increasing the error in a short time.

  Here, an example of the entire system to which the present invention is applied will be described. FIG. 3 is a block diagram showing an embodiment of the entire system used in the present invention, and shows an example in which information is transmitted / received and recorded / reproduced by broadcasting. This includes devices to which the present invention is applied. 1A is a broadcast receiving apparatus and corresponds to STB. 1B is a first recording / reproducing device, 1C is a second recording / reproducing device, 2A is a display device, 3 is an information providing station such as a broadcasting station, and 4 is a relay station. The first recording / reproducing apparatus 1B is built in the broadcast receiving apparatus 1A here, and for example, a hard disk recorder or the like is often used. The second recording / reproducing apparatus 1C is externally attached to the broadcast receiving apparatus 1A, and a DVD, a digital VTR, or the like is often used. Since 1B and 1C are recording / reproducing apparatuses, the present invention can be applied even if one or both of them are not present.

  The information providing station 3 such as a broadcasting station transmits a signal radio wave modulated by information via a relay station 4 such as a broadcasting satellite. Transmission by cable, transmission by telephone line, transmission by terrestrial broadcasting, and the like may be used. This signal radio wave received by the broadcast receiving device 1A on the receiving side is demodulated to become an information signal, and then suitable for recording on the first recording / reproducing device 1B and the second recording / reproducing device 1C as necessary. Recorded as a signal. Also, it is sent to the display device 2A. Information reproduced by the first recording / reproducing apparatus 1B and the second recording / reproducing apparatus 1C is given to the display device 2A via the broadcast receiving apparatus 1A. When a removable recording medium in which information is recorded in advance, for example, package software, is provided, the reproduction operation and the like in the second recording / reproducing apparatus 1C to which the information is attached is performed. When performing the above-described transmission, the data amount of the signal is often compressed, but this is decompressed immediately before the signal is given to the display device 2A and restored. When recording to the recording / reproducing apparatuses 1B and 1C, recording is generally performed in a compressed state. Therefore, when reproducing information from these, the information is once expanded through the broadcast receiving apparatus 1A and then given to the display apparatus 2A. In the portion where the signal is given from the broadcast receiving device 1A to the display device 2A, the compression is released and the amount of data is enormous, so it is difficult to record.

  The video / audio receiving device 2 shown in FIG. 1 corresponds to the display device 2A in FIG. The signal generator 1 in FIG. 1 corresponds to the broadcast receiver 1A alone in FIG. 3 or a combination of the broadcast receiver 1A and the second recording / reproducing device 1C. When viewing what is currently being broadcast on the display device 2A, the broadcast receiving device 1A other than the first recording / reproducing device 1B corresponds to the signal generating device 1. When displaying what is reproduced from the first recording / reproducing apparatus 1B, the entire broadcast receiving apparatus 1A including this corresponds to the signal generating apparatus 1. When displaying what is reproduced from the second recording / reproducing apparatus 1C, both the receiving apparatus 1A and the receiving apparatus 1A together correspond to the signal generating apparatus 1.

  Furthermore, a system application example to which the present invention is applied will be described.

  FIG. 4 is a block diagram showing an example of switching information transmitted / received by broadcasting and information reproduced from package software, etc., using a switcher as an example of the video / audio receiving apparatus of the present invention. 1D is a broadcast receiving apparatus and corresponds to STB. 1E is a playback device, 2B is a switcher, 5 is a display device, 42A and 42B are digital video signal line interfaces, and 41A is an audio-only interface.

  The switcher 2B switches between the video output of the broadcast receiving device 1D and the video output of the playback device 1E such as package software, and functions as the video / audio receiving device of the present invention, and can select good audio information for any input. By superimposing the audio information obtained in this manner on the video information again, there is an advantage that the video and audio information can be transmitted to the display device 5 connected to the output of the switcher 2B by connecting only the digital video interface 42C.

The circuit block diagram which shows the Example of this invention. FIG. 3 is an operation flowchart for explaining the operation of a voice switching control circuit 28 in FIG. 1. 1 is a block diagram showing an embodiment of an entire digital information transmission / reception recording system to which the present invention is applied. 1 is a system block diagram using a switcher as an embodiment of a video / audio receiving apparatus of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Signal generator, 11 ... Video signal source, 12 ... Audio signal source, 13 ... Audio superimposing circuit, 14 ... Data transmission circuit, 15 ... DAC (Digital Analogue Converter) DESCRIPTION OF SYMBOLS 1A, 1D ... Broadcast receiving device, 1B, 1C ... Recording / reproducing device, 1E ... Reproducing device, 2 ... Video / audio receiving device, 21 ... Data receiving circuit, 22 ... Audio separation circuit, 23 ... addition circuit, 24 ... video display unit, 25 ... audio processing circuit, 26 ... switch, 27 ... speaker, 28 ... audio switching control circuit, 29 ... OSD (On Screen Display) circuit, 2B ... Switcher, 210 ... Sub audio evaluation circuit, 241 ... Display recording unit, 271 ... Audio recording unit, 3 ... Broadcasting station, 4 ... Relay station, 5 ... Display device

Claims (8)

Audio reproduction, recording, or output is possible using one of the first audio signal superimposed on the video signal and the second audio signal that is input separately from the first audio signal and does not include the video signal. In a video / audio signal receiver,
A first input unit to which the first audio signal is input;
A second input unit to which the second audio signal is input;
Reproduction of the voice, as a voice signal to be used for recording or output, of the first the first input to the input portion of the second audio signal input to the audio signal or the second input unit A switch to select one,
An audio switching control circuit for determining whether or not the first audio signal is superimposed on the video signal ;
A sub voice evaluation unit for determining whether the second voice signal is input to the second input unit;
An OSD unit for displaying a message on the screen ,
The voice switching control circuit is
Controlling the switch to select the first audio signal when the first audio signal is superimposed on the video signal and the error rate of the first audio signal is smaller than a threshold ;
Controlling the switch to select the second audio signal when the first audio signal is not superimposed on the video signal ;
The first audio signal is superimposed on the video signal, and the error rate of the first audio signal is greater than a threshold, and the second audio evaluation unit inputs the second input unit to the second input unit. When it is determined that the second audio signal is not input, the switch is controlled to select the first audio signal and a message regarding the quality of the first audio signal is displayed on the screen. The video / audio signal receiving apparatus characterized by controlling the OSD unit . 2. The video / audio signal receiving device according to claim 1, wherein the first audio signal is superimposed on the video signal, and an error rate of the first audio signal is larger than a threshold value , and When the sub audio evaluation unit determines that the second audio signal is input to the second input unit, the switch is controlled to select the second audio signal. A video / audio signal receiver. 2. The video / audio signal receiving apparatus according to claim 1, wherein the first audio signal is a digital audio signal, the second audio signal is an analog audio signal, and the digital audio signal is converted into an analog signal. D / A converter
The switch selects one of the analog audio signal and an output signal from the D / A converter,
The audio switching control circuit outputs an output signal from the D / A converter when the digital audio signal is superimposed on the video signal and the error rate of the digital audio signal is smaller than a threshold value. The video / audio signal receiving apparatus, wherein the switch is controlled so as to be preferentially selected. The video / audio signal receiving device according to claim 2,
The video / audio signal reception characterized in that the message displayed by the OSD unit is a message related to a cable for transmitting the first audio signal superimposed on the video signal to the first input unit. apparatus.   4. The video / audio signal receiving device according to claim 3, wherein power supply to the D / A converter is stopped when the analog audio signal is selected by the audio switching control circuit. Video / audio signal receiver. A first audio signal to be superimposed on the video signal and a second audio signal not to be superimposed on the video signal are respectively input, and a video obtained by the video signal is displayed on a display device, and the first audio signal is displayed. In a television receiver capable of outputting sound obtained from an audio signal or a second audio signal from a speaker,
A first input unit to which the first audio signal is input;
A second input unit to which the second audio signal is input;
Reproduction of the voice, as a voice signal to be used for recording or output, of the first the first input to the input portion of the second audio signal input to the audio signal or the second input unit A switch to select one,
An audio switching control circuit for determining whether or not the first audio signal is superimposed on the video signal ;
A sub voice evaluation unit for determining whether the second voice signal is input to the second input unit;
An OSD unit for displaying a message on the display device ,
The voice switching control circuit is
Controlling the switch to select the first audio signal when the first audio signal is superimposed on the video signal and the error rate of the first audio signal is smaller than a threshold ;
Controlling the switch to select the second audio signal when the first audio signal is not superimposed on the video signal ;
The first audio signal is superimposed on the video signal, and the error rate of the first audio signal is greater than a threshold, and the second audio evaluation unit inputs the second input unit to the second input unit. When it is determined that the second audio signal is not input, the switch is controlled to select the first audio signal, and a message regarding the quality of the first audio signal is displayed on the display device. The television receiver is characterized in that the OSD unit is controlled . 7. The television receiver according to claim 6, wherein the first audio signal is superimposed on the video signal, the error rate of the first audio signal is greater than a threshold value , and the sub audio evaluation unit When it is determined that the second audio signal is input to the second input unit, the television receiver is configured to control the switch so as to select the second audio signal. 7. The television receiver according to claim 6, wherein the first audio signal is a digital audio signal, the second audio signal is an analog audio signal, and the digital audio signal is converted into an analog signal. / A converter,
The switch selects one of the analog audio signal and an output signal from the D / A converter,
The voice switching control circuit controls the switch to preferentially select an output signal from the D / A converter when an error rate of the digital voice signal is smaller than a threshold value. TV receiver.

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