JP4266905B2 - Television receiver - Google Patents

Description

  The present invention relates to a television receiver that receives a television broadcast signal on which a video signal for a plurality of channels and an audio signal synchronized with the video are superimposed, and in particular, whether or not a selected channel is being commercial broadcasted. The present invention relates to a television receiver having a discrimination function.

In recent years, when a television broadcast channel is selected on a television receiver and the broadcast program is viewed, the broadcast signal of that channel is the main part of the program or inserted between the main parts. There has been proposed a television receiver that determines whether a commercial part (hereinafter referred to as a CM part) is present and performs output control of broadcast contents in accordance with the determination result.
For example, Patent Document 1 discloses a technique for performing a CM process such as reducing the output sound volume or performing a so-called CM skip when recording in a VTR apparatus when it is determined that the part is the CM part. . Here, when the CM portion is used, the output volume is generally reduced because an audio signal having a louder volume is set (broadcast) in the CM portion than in the main portion. This saves the viewer from having to adjust the volume each time the main part is switched.
Further, Patent Document 2 discloses a technique for reducing the contrast and brightness of a screen by one step when it is determined to be the CM portion.
By the way, it is known that the CM part is often a stereo audio broadcast, and the main part is often a monaural audio broadcast or multiple audio broadcast.
Therefore, Patent Document 1 discloses a technique for determining that the CM portion has been reached when the selected channel is switched from monaural audio broadcasting or multiplexed audio broadcasting to stereo audio broadcasting.
Patent Document 2 discloses a technique for determining that the CM portion has been reached when a multiplex audio broadcast such as a movie is switched to a stereo audio broadcast or a monaural audio broadcast.
Further, in Patent Document 3, when the audio signal is a stereo audio broadcast, it is determined that the CM part is being broadcast, whether the CM part is being broadcast, and the video of the selected channel. Is a letterbox type image (image with black strips at the top and bottom edges of the screen), and performs display control such as suppressing zoom control according to the results Is disclosed.
Japanese Patent Laid-Open No. 2002-77770 Japanese Utility Model Publication No. 5-74080 Japanese Patent Laid-Open No. 10-65988

However, in reality, there are cases where stereo audio broadcasting is performed in the main part, and in such a case, the CM discrimination techniques disclosed in Patent Documents 1 to 3 have a problem that erroneous discrimination occurs. .
Thus, the conventional CM discrimination is not perfect, and it is desired to perform the CM discrimination more reliably in order to make the control based on the CM discrimination result more effective.
Accordingly, the present invention has been made in view of the above circumstances, and the object of the present invention is to provide a CM discrimination function that can further improve the certainty of whether or not a television broadcast signal is a commercial broadcast part. It is to provide a television receiver provided.

In order to achieve the above object, the present invention inputs a video signal for a plurality of channels and a television broadcast signal on which an audio signal synchronized with the video is superimposed, and selects one specific channel selected from the plurality of channels. For each of the plurality of channels, whether or not the CM is being broadcast is individually determined based on the video signal and the audio signal, and the specific channel is finally being broadcast using the individual determination result. It is configured as a television receiver that determines whether or not.
In general, the time zone during which CM broadcasting is carried out often overlaps between a plurality of broadcasting stations (channels), and when a certain channel is being broadcast, other channels are also being broadcast. There is a high possibility. Therefore, if the final determination of whether or not a specific channel is being broadcasted is made with reference to the determination result of whether or not another channel is being broadcasted, the specific channel alone is determined. Compared to the above, it is possible to further increase the certainty of determining whether or not the CM broadcast is being performed.

Here, in the present invention, it is determined that the specific channel is being broadcasted by an audio signal or a video signal (individual determination), and further, at the time point or a time zone close to that point, another channel But if it is determined that the CM broadcast (individual discrimination), the specific channels you final determination that the broadcast CM.
As a result, it is possible to suppress the frequency of misjudgment that the CM is being broadcast, even though the CM is not actually being broadcast, and to improve the certainty of the CM discrimination.
In addition, as a method of individually determining whether each of the plurality of channels is under CM broadcasting, based on a determination result whether the video signal in the channel is a letterbox type video signal, or A case where the channel is determined based on the determination result as to whether the channel is a stereo broadcast or a case where the channel is determined based on both of them is considered.
In general, a CM audio broadcast is often a stereo audio broadcast, and a main audio broadcast is often a monaural audio broadcast or multiple audio broadcast. In many cases, the letterbox type video is a movie video (that is, the main video). Therefore, it is possible to individually determine whether or not each of the plurality of channels is being broadcasted on the basis of these pieces of information.

  According to the present invention, the final determination as to whether or not a specific channel is being broadcasted is made with reference to the determination result as to whether or not another channel is being broadcasted. CM broadcasts are often played simultaneously in the same time zone, and according to such a method for determining CM broadcasts, it is possible to determine whether or not CM broadcasts are being performed as compared to the case where the specific channel is determined alone. Certainty can be further increased.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that the present invention can be understood. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.
FIG. 1 is a schematic configuration diagram of a television receiver A according to an embodiment of the present invention, and FIG. 2 is a schematic configuration diagram of a television receiver B according to an embodiment of the present invention.
Hereinafter, the schematic configuration of the television receiver A according to the embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 1, the television receiver A includes a plurality of tuners 2, a plurality of detection circuits 3 corresponding to each tuner 2, a plurality of channel-by-channel CM discrimination circuits 4, a channel selection control circuit 5, and a video processing circuit. 6, a video output unit 7, an audio processing circuit 8, an audio output unit 9, a specific channel CM discrimination circuit 10, a control unit 11, an input unit 12, and the like.

The receiving antenna 1 receives a television broadcast signal on which video signals for a plurality of channels and an audio signal synchronized with the video are superimposed.
Each of the tuners 2 (an example of signal input means) receives the television broadcast signals for a plurality of channels received by the receiving antenna 1, and each selects one of the plurality of channels. .
Each of the detection circuits 3 extracts the video signal and the audio signal from the signals of the respective channels selected by the tuners 2 (signals for one channel extracted from the television broadcast signal).
The per-channel CM discriminating circuit 4 individually discriminates whether or not each channel is under CM broadcasting based on the audio signal extracted by each of the plurality of detection circuits 3. Hereinafter, the determination as to whether or not the CM is being broadcast for each channel is referred to as individual CM determination.
The channel selection control circuit 5 controls which of the plurality of tuners 2 is selected from among the plurality of channels received by the receiving antenna 1.
The video processing circuit 6 performs predetermined processing on the video signal (for example, separation of horizontal and vertical synchronization signals from the video signal, generation of a clock signal phase-synchronized with the synchronization signal, luminance signal and color signal from the video signal) Separation, predetermined image quality improvement processing, etc.).
The video output unit 7 is means for outputting the video signal such as a display.
The audio processing circuit 8 performs predetermined processing (volume adjustment processing, equalization processing according to the characteristics of the audio output unit 9, surround processing, etc.) on the audio signal.
The audio output unit 9 is means for outputting the audio signal such as a speaker.
The specific channel CM discriminating circuit 10 finally discriminates whether or not the specific channel is being broadcasted based on the result of individual discrimination by the channel-specific CM discriminating circuit 4.

The control unit 11 includes an MPU and its peripheral devices such as ROM and RAM, and performs overall control of the television receiver A by executing a control program stored in advance in the ROM. is there. The input unit 12 is a general term for a receiving unit for receiving an operation signal of the television receiver A by a remote controller or operation switches provided on the outer surface of the television receiver A, for example.
In the present embodiment, a target channel output from the video output unit 7 such as a display and the audio output unit 9 such as a speaker is referred to as a specific channel.
The specific channel is selected from a plurality of channels received by the receiving antenna 1 when an operation signal from the remote controller or the like is input to the control unit 11 through the input unit 12 (an example of channel selection means). And set (stored) in the control unit 11.

The channel selection control circuit 5 inputs the specific channel set in the control unit 11, and the specific channel is selected by a specific one of the plurality of tuners 2 (hereinafter referred to as a specific tuner 2a). As a result, the specific tuner 2a is controlled.
The channel selection control circuit 5 has a set of channels (a set of channels of private broadcasting stations, hereinafter referred to as a private broadcast channel group) that can be a target of individual CM discrimination by each of the plurality of channel-by-channel CM discrimination circuits 4 in advance. Set (stored) so that each of the specific tuner 2a and the remaining tuner 2 (hereinafter referred to as other tuner 2b) selects a different channel (extracts a channel signal) from the private channel group. The tuner 2 is controlled.
Here, the commercial channel group can be arbitrarily set by an input operation from the input unit 12.
Hereinafter, the detection circuit 3 and the channel-specific CM determination circuit 4 corresponding to the specific tuner 2a are referred to as a specific detection circuit 3a and a specific-channel CM determination circuit 4a, respectively, and the detection corresponding to the other tuner 2b. The circuit 3 and the per-channel CM discriminating circuit 4 are referred to as other detection circuit 3b and other per-channel CM discrimination circuit 4b, respectively.

The plurality of tuners 2 select a plurality of channels including the specific channel according to the control by the channel selection control circuit 5 as described above, and the video signals of the respective channels are transmitted to the detection circuits 3 respectively. .
The signal of each channel transmitted to the detection circuit 3 is subjected to video detection and audio detection (extraction of video signal and audio signal), respectively, and the audio signal is transmitted to the CM discrimination circuit 4 for each channel. Further, only the video signal and the audio signal (that is, the video signal and the audio signal of the specific channel) detected by the specific detection circuit 3a are transmitted to the video processing circuit 6 and the audio processing circuit 8, respectively. The
In this way, the plurality of tuners 2 and the detection circuits 3 (these configurations are an example of channel extraction means) allow the video signals and audio for a plurality of channels including the specific channel in the television broadcast signal. A signal is extracted.

Based on the audio signal transmitted from the corresponding detection circuit 3 (an example of a part of the channel extraction means), each of the CM discrimination circuits 4 for each channel determines whether or not a CM broadcast is being performed for each channel. Discriminating (discriminating individual CM).
In the present embodiment, the audio signal of each channel is analyzed by the per-channel CM discriminating means 4 and it is discriminated whether or not the channel to be discriminated is a stereo audio broadcasting channel. When it is determined that the channel is a stereo audio broadcast channel, the individual CM determination is made that the channel is being broadcasted.
Note that a method for determining whether or not the channel to be determined is a stereo audio broadcast channel is, for example, the frequency of the control signal included in the audio signal (no control signal for monaural broadcast, 982. It is sufficient to follow a conventionally known method such as detecting 5 Hz and 922.5 Hz for a multiplexed audio signal.
The result of the individual CM discrimination as to whether or not each of the plurality of channels is under CM broadcast by each channel discrimination circuit 4 is input to the specific channel CM discrimination circuit 10.

A channel information signal indicating which channel the specific channel set in the control unit 11 is transmitted to the specific channel CM discriminating circuit 10. Then, the specific channel CM discriminating circuit 10 finally discriminates whether or not the specific channel is being broadcasted as follows, for example, from the channel information signal and the result of the individual CM discrimination.
Based on the individual CM discrimination by the channel CM discriminating circuit 4, it is determined that the specific channel is being broadcasted as an individual CM, and one or more channels other than the specific channel are being broadcasted as a CM. If it is, it is finally determined that the specific channel is being broadcasted on the CM.
On the other hand, when there is no channel other than the specific channel determined to be CM broadcast by the individual CM determination, or when the specific channel is not determined to be CM broadcast, the specific channel is CM broadcast. If it is not in the middle, it is finally determined.

Here, only when it is determined by the individual CM determination that the specific channel is being broadcasted on the CM, and a plurality of channels other than the specific channel are determined on the CM broadcast. It may be finally determined that the specific channel is being broadcast on CM.
As for the channels other than the specific channel, even if the channel is switched to the main broadcast for a while after the result of determining that each of the plurality of channels is being broadcasted by the CM by the channel-by-channel CM discrimination circuit 4. It is conceivable to hold (for example, about several seconds).
In this way, even if the specific channel and a channel other than the specific channel are not determined to be strictly CM broadcast at the same time by the individual CM determination, for example, the specific channel is being CM broadcast by the individual CM determination. If it is determined that one or a plurality of channels other than the specific channel are being broadcasted in the CM in the time zone close to that, the specific channel is being broadcasted. It can be configured to be finally determined.
On the other hand, various conditions can be considered for releasing the state in which it is determined that the specific channel is being broadcasted (determined that the broadcast is switched from the CM broadcast to the main broadcast). For example, when it is determined by the individual CM determination that the specific channel is not being broadcast, or when it is determined that all channels other than the specific channel are not being broadcast, the specific channel is being broadcast. It may be possible to cancel the final determination result that there is (determine that the CM is not being broadcast).

While the specific channel is finally determined to be in CM broadcast by the above-described determination method, the specific channel CM determination circuit 10 transmits a predetermined CM signal to the control unit 11.
Here, the television receiver A according to the embodiment of the present invention has a switching setting function between a normal mode and an audio suppression mode, and these modes are switched according to an external operation by a remote controller or the like. It is done.
In the audio suppression mode, when it is finally determined that the specific channel is in a CM broadcast, the control unit 11 controls the audio processing circuit 8 to output the audio output unit 9. In this mode, the output volume of the audio signal is suppressed more than when it is determined that the main program is being broadcast (not being broadcasted). On the other hand, the normal mode is a mode in which the output volume is not adjusted based on the final determination result as to whether or not the CM is being broadcast.

In the state where the voice suppression mode is set, the following control is performed.
First, when it is finally determined that the specific channel is in a CM broadcast, when the user performs an operation for adjusting the volume (for example, an operation for decreasing the volume) through the input unit 12, an output volume is set according to the operation. The sound processing circuit 8 is controlled so as to adjust (decrease) the sound, and the volume after adjustment (decrease) is stored in a storage unit (not shown) built in the control unit 11. Thereafter, every time it is finally determined that the specific channel is being broadcasted again, the control unit 11 automatically controls the audio processing circuit 8 and is output from the audio output unit 9. The volume of the sound is adjusted according to the information on the volume during the CM broadcast stored in the storage unit (that is, the volume after being adjusted by the user during the CM broadcast).
In addition, when it is finally determined that the specific channel is not in a CM broadcast, when the user performs an operation for adjusting the volume through the input unit 12 (for example, an operation for increasing the volume), the output volume is adjusted according to the operation. The sound processing circuit 8 is controlled to adjust (increase), and the volume after adjustment (increase) is stored in a storage unit (not shown) built in the control unit 11. After that, every time it is finally determined that the specific channel is not being broadcasted in the CM (the main program is being broadcast), the control unit 11 automatically controls the audio processing circuit 8, The volume of the audio output from the audio output unit 9 is adjusted according to the volume information during the main program broadcast stored in the storage unit (that is, the volume after being adjusted by the user during the main program broadcast).
The volume information during the CM broadcast stored in the storage unit is set when the voice suppression mode is set, and when it is finally determined that the specific channel is during the CM broadcast, It is updated when the volume is adjusted again by the user. Similarly, the volume information stored in the storage unit during the main broadcast is the case where the audio suppression mode is set, and the specific channel is not being broadcasted in CM (the program main broadcast is being broadcast). Updated when the user adjusts the volume again.
By having such a control function, the user does not need to perform a special operation for storing information related to the volume during the CM broadcast or the volume during the main broadcast, and performs a natural operation that is normally performed. In the meantime, the information regarding the volume during the CM broadcast and the volume during the main broadcast is automatically stored in the apparatus, so that the operation is easy.

In the above-described embodiment, the individual CM discrimination for each of the plurality of channels is performed based on the audio signal of each channel (based on whether or not the channel is a stereo audio broadcast channel).
On the other hand, an embodiment in which the individual CM determination as to whether or not each of the plurality of channels is under CM broadcast is performed based on the video signal of each channel. Hereinafter, an embodiment for performing the individual CM discrimination based on the video signal will be described.
In the television receiver according to this embodiment, both the audio signal and the video signal detected by the detection circuit 3 are input to the channel-by-channel CM discrimination circuit 4.
Of the channels, for the channels on which the movie program is being broadcast, the channel-specific CM discriminating circuit 4 converts the video signal into a so-called letterbox type video signal (video signal having black strips above and below the video). It is determined whether or not the CM is being broadcast based on whether or not.

In the broadcast of a movie program, a letterbox type video signal is often used during the main movie broadcast, and a letterbox type video signal is rarely used during a CM broadcast. Therefore, for a channel that is broadcasting a movie program, the channel-by-channel CM discrimination circuit 4 analyzes the video signal to determine whether it is a letterbox type video signal. In the case of the box type, it may be determined that the channel is not being broadcasted (individually determined), and if it is not a letterbox type video signal, it is determined that the channel is being broadcasted (individually determined).
Here, whether or not each channel is broadcasting a movie program is automatically determined by, for example, an EPG (Electronic Program Guide) superimposed on the signal of each channel, or a user's operation input by the remote controller or the like. It is possible to set according to the above.
It is also conceivable that whether or not to perform the individual CM discrimination based on such a video signal can be selected by mode selection by the user.
For channels that are not being broadcasted in movie programs, the individual CM discrimination is performed by the channel-by-channel CM discrimination circuit 4 according to whether or not the discrimination target channel is a stereo broadcast, as in the above-described embodiment. You can do it.
In addition, as a method for determining whether or not the video signal is a letterbox type, a conventionally known method disclosed in Patent Document 3 or the like may be used, such as detecting a black belt portion of a display video.

An embodiment in which the individual determination is performed based on both the audio signal and the video signal is also conceivable.
For example, for a channel that is broadcasting a movie program, if the broadcast is a stereo audio broadcast and the video signal is not of the letterbox type, it is determined that the channel is a CM broadcast, and the channel is monaural. It may be possible to perform the individual determination processing such as determining that the channel is not in CM broadcast when the channel is an audio broadcast or multiple audio broadcast, or the video signal of the channel is not of the letterbox type. .

In the above-described embodiments and examples, an example is shown in which the output level (volume) of the audio signal in the specific channel is adjusted when it is finally determined that the specific channel is being broadcast on CM. Control based on the determination result is not limited to this. For example, when it is finally determined that the specific channel is in a CM broadcast, it is possible to switch to the multi-screen display of the specific channel and other channels.
FIG. 2 shows a schematic configuration of the television receiver B according to the embodiment of the present invention having such a function. The television receiver B includes a video composition circuit 13 for displaying two channels on a multi-screen when it is finally determined that the specific channel is being broadcast on a CM.
In the television receiver B, the specific channel and the specific channel when the control unit 11 finally determines that the specific channel and the specific channel are being broadcasted based on input information from the input unit 12 in advance. At the same time, subchannels to be displayed on the multi-screen are set, and the setting information is transmitted to the channel selection control circuit 5.

In the television receiver B, the channel selection control circuit 5 selects the specific channel by the specific tuner 2a and selects the subchannel by any one of the other tuners 2b. Each tuner 2 is controlled. Also, the video processing circuit 6 inputs the video signal from the specific detection circuit 3a and the video signal from the other detection circuit 3b corresponding to the other tuner 2b for selecting the subchannel. The signal is subjected to various processes and then transmitted to the video composition circuit 13.
When it is finally determined that the specific channel is being broadcasted on the CM, the control unit 11 transmits a video synthesis command signal to the video synthesis circuit 13. Then, while the video synthesis command signal is received in the video synthesis circuit 13, the video signal synthesis processing for each of the specific channel and the sub-channel is performed, and the synthesized video signal is displayed on the video display. Is output to the unit 7. As a result, the video screens of the two video signals are displayed on the multi-screen by the video output unit 7.
On the other hand, when it is finally determined that the specific channel is not being broadcasted in CM (the main part is being broadcast), only the video signal of the specific channel is left as it is by the video composition circuit 13 (no composition processing is performed). B) is output to the video display unit 7. As a result, the video screen of the specific channel is displayed on the single screen by the video output unit 7.
When it is determined by such a television receiver B that the specific channel is being broadcasted on the CM, the video of the subchannel is displayed on the multi-screen, so that the user can view the video of the subchannel. Can be grasped.
For example, if you are watching a movie on the specific channel and select a baseball broadcast channel or the like as the sub-channel in advance, the movie broadcast automatically changes from the main broadcast to the CM broadcast. Movie broadcast channels (specific channels) and baseball broadcast channels (sub-channels) are displayed on multiple screens, and the status of baseball broadcasts (whether or not the number of batting order of specific batters has come around during the CM broadcast of movie programs) ) Can be confirmed.

In the above-described embodiment, an example in which the result of the individual CM determination regarding a channel other than the specific channel (hereinafter referred to as another channel) is held for a certain period of time is shown. In this case, the timing at which the other channel is switched to CM broadcasting is shown. When the specific channel is slightly delayed from the timing of switching to the CM broadcast, the result of the individual CM determination for the other channel does not contribute to the determination that the specific channel is being CM broadcast.
Therefore, in addition to holding the result of the individual CM determination for the other channel for a certain time, the path of the video signal and audio signal of the specific channel, for example, the path from the video processing circuit 6 to the video output unit 7 , And a delay circuit is provided in each path from the audio processing circuit 8 to the audio output unit 9, and a timing at which the video signal and audio signal of the specific channel are output from the video output unit 7 and the audio output unit 9 Can be delayed for a predetermined time (for example, several seconds).
When such a delay circuit is provided, whether the signal of the specific channel output from the video output unit 7 and the audio output unit 9 at a certain time point (hereinafter referred to as an output time point) is a signal during CM broadcast. Including the result of the individual CM determination for the signal of the specific channel output at the output time point and the time point from the time point preceding the output time point to the predetermined time point (delay time). It is conceivable to perform the determination based on the result of the individual CM discrimination for the signal of the other channel in the band.
Note that the signal of the specific channel output at the output time is the signal at the output time when the individual CM determination is performed using the signal (audio signal or video signal) of the specific channel after delay processing. In the case where the individual CM determination is performed using the signal of the specific channel before delay processing, the signal at a time point before the predetermined time (delay time) before the output time point is indicated.

For example, when the result of the individual CM determination that the signal of the specific channel output at the output time point is a signal during CM broadcast comes out, the output time point from the predetermined time (delay time) before that If the result of the individual CM discrimination that the other channel is currently being broadcasted is obtained until the end, it is finally determined that the specific channel output after the delay process is being broadcasted. Output control (voice suppression, multi-screen display, etc.) is performed according to the final determination.
As a result, even when the timing at which the other channel is switched to the CM broadcast is slightly delayed (maximum, the predetermined time) from the timing at which the specific channel is switched to the CM broadcast, the result of the individual CM determination of the other channel. This is reflected in the fact that it is determined that the specific channel is being broadcast on CM.
In this way, by delaying the signal of the specific channel and holding the result of the individual CM discrimination for the other channel for a certain period of time, the specific channel is in a CM broadcast. If it is determined that the other one or more channels are determined to be being broadcasted by the channel-by-channel CM determination circuit 4 at both the current time point and the time zone before and after that time point, It is possible to configure a television receiver that finally determines that a channel is being commercial broadcast.

1 is a schematic configuration diagram of a television receiver A according to an embodiment of the present invention. The schematic block diagram of the television receiver B which concerns on the Example of this invention.

Explanation of symbols

A ... Television receiver B according to an embodiment of the present invention B ... Television receiver 1 according to an embodiment of the present invention ... Receiving antenna 2 ... Tuner 3 ... Detection circuit 4 ... CM discrimination circuit 5 for each channel ... Channel selection control Circuit 6 ... Video processing circuit 7 ... Video output unit 8 ... Audio processing circuit 9 ... Audio output unit 10 ... Specific channel CM discriminating circuit 11 ... Control unit 12 ... Input unit 13 ... Video composition circuit

Claims (2)

A signal input means for inputting a television broadcast signal on which a video signal for a plurality of channels and an audio signal synchronized with the video are superimposed;
Channel selection means for selecting one specific channel from a plurality of channels in the television broadcast signal;
Channel extraction means for extracting the video signal and / or the audio signal for a plurality of channels including the specific channel from the television broadcast signal;
For each of the plurality of channels extracted by the channel extracting means, a per-channel CM determining means for determining whether or not a commercial broadcast is being performed based on the video signal and / or the audio signal of each channel;
Specific channel CM discriminating means for discriminating whether or not the specific channel is under commercial broadcasting based on the discrimination result of the channel-by-channel CM discriminating means;
In Rute revision receiver such comprises a,
When the specific channel CM discriminating means discriminates that the specific channel is being commercial broadcast by the channel-by-channel CM discriminating means, one or more other channels at that time and / or a time zone close to that time The television receiver is characterized in that it is determined that the specific channel is being commercial broadcasted when it is determined that the commercial is being broadcast by the channel-by-channel CM determining means . The channel-by-channel CM discrimination means determines whether the video signal is a letterbox type video signal and whether or not the channel is a stereo broadcast channel based on one or both commercial broadcasts. The television receiver according to claim 1, wherein it is determined whether or not it is inside.

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