JP2008028554A - Signal transmission/reception system, signal transmitter, signal receiver, signal transmission/reception method, signal transmission method, and signal reception method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a signal transmission/reception system or the like that minimizes temporary distortion of a displayed video image occurring during switching of video signal formats. <P>SOLUTION: Information regarding a format after switching and information regarding timing of switching the formats are inserted into a blanking section of the video signal to be transmitted. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a signal transmission / reception system, a signal transmission device, a signal reception device, a signal transmission / reception method, a signal transmission method, and a signal reception method that can minimize a temporary display video disturbance.

  In recent years, with the development of TV broadcasting systems and the advancement of video display devices, video display devices can receive video signals in a wide variety of formats and display images in those formats. Along with this, an increasing number of devices such as camcorders and video recorders that can supply video signals in a wide variety of formats are also increasing.

  Many of these devices can switch the format of the video signal during the transmission of the video signal, for example, by the user inputting a key, and continuously transmit the video signal in the switched format. can do.

  Here, in the conventional signal transmission / reception system, when the format of the video signal transmitted from the transmission-side device is switched to a different format, the synchronization is suddenly switched in the reception-side device. There was a problem that.

  In view of such problems, various measures have been taken so far. For example, in Patent Document 1, reception is performed by inserting additional information including a signal for determining the format of a video signal in a vertical blanking interval of a plurality of video signals having different formats in a video signal to be transmitted. For the video display device on the side, a technology is disclosed that can easily determine the format of a video signal that is difficult to determine only by the frequency of the synchronization signal.

JP-A-11-196393

  By the way, the conventional signal transmission / reception system has a procedure for switching the synchronization of the display video after the reception side video display device detects the discontinuity of the synchronization of the video signal transmitted by the transmission side device. The delay and unsightly display could not be improved.

  On the other hand, for example, in Patent Document 1, since the format of the video signal can be easily discriminated, it is possible to shorten the time until the format switching is detected. However, since a predetermined time is required, temporary display is performed. It has been difficult to minimize image disturbance.

  Therefore, the present invention has been made in view of such circumstances, and a signal transmission / reception system, a signal transmission device, and a signal that can minimize the temporary disturbance of a display image that occurs when the format of a video signal is switched. It is an object of the present invention to provide a receiving apparatus, a signal transmitting / receiving method, a signal transmitting method, and a signal receiving method.

  Other objects of the present invention and specific advantages obtained by the present invention will become more apparent from the description of embodiments described below.

  In order to solve the above problems, a signal transmission / reception system according to the present invention is a signal transmission / reception system capable of transmitting a video signal from a signal transmission apparatus to a signal reception apparatus, and the signal transmission apparatus generates a video signal. Based on the video signal generation means and the control signal for switching the format of the video signal to a different format, blanking of the video signal generated by the signal generation means includes information relating to the format after switching and information relating to switching timing. An information insertion means for inserting into the section; and a signal transmission means for transmitting the video signal into which the information is inserted by the information insertion means, wherein the signal receiving device receives the video signal transmitted by the signal transmission means. After the switching from the video signal received by the receiving means and the signal receiving means Information retrieving means for retrieving information relating to the format and information relating to the switching timing, information relating to the format after switching retrieved by the information retrieving means, and information relating to the switching timing, and reproduction switching means for switching the video reproduction, Is provided.

  In order to solve the above problem, the signal transmission device according to the present invention switches based on a video signal generating means for generating a video signal and a control signal for switching the format of the video signal to a different format. Information insertion means for inserting information relating to the later format and information relating to switching timing into the blanking interval of the video signal generated by the signal generation means, and signal transmission for transmitting the video signal in which the information is inserted by the information insertion means Means.

  In order to solve the above-described problem, a signal receiving apparatus according to the present invention includes a signal receiving unit that receives a video signal, information on a format after switching from the video signal received by the signal receiving unit, and a switching timing. Information retrieving means for retrieving information relating to the information, and reproduction switching means for switching video reproduction based on the information relating to the format after switching taken out by the information extracting means and the information relating to the switching timing.

  In order to solve the above problems, a signal transmission / reception method according to the present invention includes a signal generation step for generating a video signal and a control signal for switching the format of the video signal to a different format. Information insertion step for inserting information on the format of the video and information on timing for switching into the blanking interval of the video signal generated by the signal generation step, and a signal transmission step for transmitting the video signal having the information inserted by the information insertion step A signal receiving step for receiving the video signal transmitted in the signal transmitting step, an information extracting step for extracting information on the format after the switching and information on the switching timing from the video signal received in the signal receiving step; Above information Information about the format of the switched taken out by take-out means, based on the information about the switching timing, and a playback switching step of switching the video playback.

  In order to solve the above problems, a signal transmission method according to the present invention includes a signal generation step for generating a video signal and a switching signal based on a control signal for switching the format of the video signal to a different format. Information insertion step for inserting information on the format of the video and information on timing for switching into the blanking interval of the video signal generated by the signal generation step, and a signal transmission step for transmitting the video signal having the information inserted by the information insertion step And comprising.

  Furthermore, in order to solve the above problems, a signal receiving method according to the present invention includes a signal receiving step for receiving a video signal, information on a format after switching from the video signal received by the signal receiving step, and a switching timing. An information extraction step for extracting information related to the information, a reproduction switching step for switching video reproduction based on the information regarding the format after switching extracted by the information extraction step, and the information regarding the switching timing.

  According to the present invention, since information related to the format after switching and information related to timing for switching the format are inserted into the blanking interval of the video signal to be transmitted, timing for switching the format and format after switching in the receiving device. It is possible to know in advance, and it is possible to minimize the temporary disturbance of the display video that occurs when the video signal format is switched.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. The present invention is applied to, for example, a signal transmission / reception system 1 configured as shown in FIG.

  This signal transmission / reception system 1 includes a signal transmission device 10 constituting a part of a video signal transmission device (camcorder 2 in FIG. 1) such as a camcorder and a video recorder, and a video such as a TV (television) and a monitor. A signal receiving device 20 constituting a part of a device (TV 3 in FIG. 1) on the signal receiving side, and the signal transmitting device 10 and the signal receiving device 20 are connected by a wired or wireless interface 4. is there.

  In the signal transmission / reception system 1, the signal transmission device 10 includes, for example, a video signal generation block 11, an audio signal generation block 12, a control microcomputer block 13, and a signal multiplexing processing block 14 as shown in the block diagram of FIG. 2. And a parallel / serial conversion block 15, a transmission encoding processing block 16, and a driver 17.

  The video signal generation block 11 generates a video signal of a predetermined format based on the control signal of the control microcomputer block 13 and outputs it to the signal multiplexing processing block 14. For example, a video signal may be generated by photoelectrically converting a subject image using an image sensor such as a CCD or CMOS, or a video signal may be generated by a video playback device. Here, the format of the video signal indicates the frequency and angle of view of the horizontal / vertical synchronizing signal of the video signal, but is not limited thereto, for example, settings related to the number of quantization bits of the signal and the color space of the color signal, etc. May be included. FIG. 3 shows an example of the format of the video signal generated by the video signal generation block 11. For example, the frequency of the horizontal / vertical synchronizing signal of the format in the device having the D4 terminal has variations such as 480 / 60i, 480 / 60p, 720 / 60p, 1080 / 60i.

  The audio signal generation block 12 generates an audio signal of a predetermined format based on the control signal of the control microcomputer block 13 and outputs it to the signal multiplexing processing block 14. For example, an audio signal may be generated by a microphone, or an audio signal may be generated by an audio playback device. Here, the format of the audio signal indicates, for example, a sampling frequency.

  The control microcomputer block 13 performs overall control of each unit of the signal transmission device, generates auxiliary data, and outputs the auxiliary data to the signal multiplex processing block 14. The control microcomputer block 13 receives, for example, a control signal for switching the format of the video signal by a key input from the user, outputs a control signal for switching the format to the video signal generation block 11, and is selected by the user. The information regarding the format of the switched video signal and the information indicating how many frames the format is to be switched to are output to the signal multiplex processing block 14 as auxiliary data.

  The control microcomputer block 13 receives a control signal for switching the format of the audio signal, for example, by a key input from the user, and outputs a control signal for switching the format to the audio signal generation block 12. The information about the format of the audio signal after switching selected by the above and the information about how many frames later the format is switched to are output to the signal multiplexing processing block 14 as auxiliary data.

  The signal multiplex processing block 14 stores the audio signal and auxiliary data in the blanking interval of the video signal.

  The parallel / serial conversion block 15 converts the signal superimposed in the signal multiplexing processing block 14 from a parallel signal into a serial signal.

  The transmission encoding processing block 16 performs an encoding process for transmitting the video signal converted into the serial signal in the parallel / serial conversion block 15.

  The driver 17 amplifies and transmits the video signal processed in the transmission encoding processing block 16. In the embodiment, the description will be made assuming that the video signal to be transmitted conforms to the SDI standard which is a standard serial transmission method of the baseband video signal, but the present invention is not limited to this. The serial transmission method is not limited to the SDI standard, and a parallel transmission method may be used.

  This SDI standard is defined by the Society of Motion Picture and Television Engineers (SMPTE), which converts digital data including video data and audio data into serial data for transmission. Stipulate.

  In the signal transmission / reception system 1, the signal receiving device 20 includes, for example, a receiver 21, a waveform equivalent processing block 22, a data detection processing block 23, and a serial / parallel conversion block, as shown in the block diagram of FIG. 24, a signal separation processing block 25, and a control microcomputer 26.

  The receiver 21 receives and amplifies the transmitted video signal, and then outputs it to the waveform equivalent processing block 22.

  The waveform equivalent processing block 22 corrects the waveform distortion at the time of transmission and outputs it to the data detection block 23.

  The data detection block 23 detects the signal subjected to the waveform distortion correction as a 0/1 digital data series and outputs it to the serial / parallel conversion block 24.

  The serial / parallel conversion block 24 converts a serial signal detected as a digital data series into a parallel signal and outputs the parallel signal to the signal separation processing block 25.

  The signal separation processing block 25 separates the audio data and auxiliary data from the digital data series, and outputs them as independent data together with the video data as the main data.

  The control microcomputer block 26 performs overall control of each part of the signal receiving device and, for example, mutes when switching the video playback (audio playback) format based on the auxiliary data separated in the signal separation processing block 25. Control each part to apply.

  Here, serial digital data transmitted according to the SDI standard will be described. The serial digital data has a structure as shown in FIG. One line of pixels in the horizontal direction of the video signal is one unit, and valid video data is sandwiched between timing reference signals called SAV (Start of Active Video) and EAV (End of Active Video).

  Arbitrary auxiliary data can be stored in the section between EAV and SAV. The present invention stores the format of the video signal to be output next in this auxiliary data storage area and the number of frames until the video signal is output in that format, and transmits it to the receiving device. On the other hand, it tries to inform the stream format as soon as possible. Note that a section between EAV and SAV in the SDI standard corresponds to a blanking section of the video signal before sampling.

  Here, with reference to FIG. 6, the structure of the auxiliary data defined by the SDI standard will be described. Auxiliary data consists of an ancillary data flag of 3 words, an data ID of 1 word, a data block number / secondary data ID, and a data count. , User data words (User Data Words), and check sum data (Check Sum). One word can store 8-bit or 10-bit data. In one word of the user data word of the auxiliary data, for example, the format of the video signal to be output next in the format shown in FIG. 7 and the number of frames until output can be stored.

  Regarding the data to be stored, as the format of the video signal, an appropriate number is assigned to the format specified by the SDI standard, for example, as shown in FIG. 3, and the number corresponding to the format to be output next is assigned to the user data word. Is stored in the lower 4 bits. As for the number of frames until the switching, after receiving the switching instruction from the user, the control microcomputer block 13 determines the state of the device, and then gives a margin of several frames before executing the format switching. The number of minutes is stored in the upper 4 bits of the user data word.

  Next, the operation of the signal transmission / reception system 1 when the video signal format is switched will be described.

  First, the operation of the signal transmission device 10 will be described. For example, when the transmitting device is a video camera, the format of the video signal is determined by the setting of the internal signal processing circuit, and the control microcomputer block 13 of the system generally performs the setting. The first trigger is a key input by the user, thereby starting a series of switching operations.

  With reference to FIG. 8, the format switching timing in the signal transmission apparatus will be described.

  First, the control microcomputer block 13 receives a control signal for switching the format by a user key input or the like. In the embodiment, the user switches from the SD signal of 480i to the HD signal of 1080i at the timing shown in the “user setting mode” in FIG. Even when the control microcomputer block 13 receives the control signal, the control microcomputer block 13 does not immediately execute the setting change, and deliberately delays the setting change to the system in order to allow the receiving device to have a processing margin. In the embodiment, the video signal generation block 11 delays the video signal by 5 frames from the user setting mode based on the control signal of the control microcomputer block 13 as shown in the “microcomputer setting mode” in FIG. As a result, the switching of “video signal output” is also delayed by 5 frames.

  Further, the control microcomputer block 13 inserts the additional data defined in FIG. 7 into the blanking interval of the video signal. As shown in “frame count” in FIG. 8, the additional data “frame count” counts down to 5, 4, 3, 2, and 1 for each frame from the frame immediately after switching by the user. ", 5 (1080i, 1.485 Gbps), which is the number of the next format specified as shown in FIG. 3, is stored as a value. Note that two types of values to be stored store 0 as a default value, and as long as signals of the same format continue, no value other than 0 is entered.

  Next, the operation of the signal receiving device 20 will be described with reference to FIG. The receiving device is assumed to be a general display device (monitor). The control microcomputer block 26 of the signal receiving device 20 always monitors the “frame count” and “next format” of the additional data in the stream, and if the “frame count” and “next format” are the default values of 0. Do nothing.

  If the value of the “frame count” is other than 0, the control microcomputer block 26 can know in advance that the format is switched in the frames after the value of the “frame count” (for example, 5).

  The control microcomputer block 26 can prepare for switching using this interval. For example, muting (display OFF) is performed at the timing shown in “Mute control signal” in FIG. Further, for example, the clock and the horizontal or vertical synchronizing signal are switched without showing any disturbance in the state where the display is OFF. In addition, a clock generation circuit on the receiving side that uses VCXO generally requires time to pull in when the frequency changes greatly due to its characteristics, but it is possible to earn that time.

  In the embodiment shown in FIG. 9, when the “frame count” changes from 3 to 2, the “mute control signal” is turned on and the “display signal output” mute is turned on. Four months after the mute is turned on, the “mute control signal” is turned off, and the “display signal output” mute is turned off.

  In the “microcomputer setting mode” shown in FIG. 9, the control microcomputer block 26 changes the format when the “frame count” changes from 1 to 0. As a result, the display on the monitor looks like the “display signal output” shown in FIG. 9, and it is possible to hide the disturbance of the video due to the switching of the synchronous system.

  The numerical values given here are merely examples, and can be set at an appropriate timing according to the convenience of the system. In addition, the “frame count” of the additional data transmitted by the signal transmission device 10 indicates the minimum value of the time until the format is switched. Therefore, if the switching is in time, the internal setting including the mute in the signal reception device 20 is performed. You can choose the timing freely. For example, if time is required until the system is stabilized after the synchronization is set, the timing for turning mute off may be delayed.

  In this embodiment, an example in which information regarding the horizontal and vertical synchronization signals of the video signal and information regarding the angle of view is stored as auxiliary data is shown as the format. However, the format is not limited thereto, for example, signal quantization It is also possible to store information relating to the number of bits and settings relating to the color space of the color signal as auxiliary data.

  Further, taking the SDI standard as an example, the audio signal is multiplexed and transmitted in the blanking interval of the video signal, but information related to the next audio signal to be subsequently transmitted can be stored in the auxiliary data as well. Is possible. For example, when the sampling frequency is different, muting is required at the switching unit. However, by using this method, it is possible to notify the receiving side device of an accurate mute timing.

  When this method is used, tracking of the system on the transmission side is slightly delayed with respect to key input on the transmission side, but if this processing is not supported on the reception side, the transmission side If this function can be turned ON / OFF, this can be avoided.

It is a figure which shows one Embodiment of a signal transmission / reception system. It is a block diagram of the signal transmitter in one embodiment of the present invention. It is a figure which shows one Embodiment of the format of a video signal. It is a block diagram of the signal receiver in one embodiment of the present invention. It is a figure which shows the structure of the video signal of a SDI standard. It is a figure which shows the structure of the auxiliary data of the video signal of a SDI standard. It is a figure which shows the structure of the additional data in one Embodiment of this invention. It is a figure for demonstrating the operation | movement at the time of the format switch in a signal transmitter. It is a figure for demonstrating the operation | movement at the time of the format switch in a signal receiver.

Explanation of symbols

1 signal transmission / reception system, 2 camcorder, 3 TV (television), 4 interface, 10 signal transmission device, 11 video signal generation block, 12 audio signal generation block, 13 control microcomputer block, 14 signal multiplex processing block, 15 parallel serial Conversion block, 16 Transmission encoding processing block, 17 Driver, 20 Signal reception device, 21 Receiver, 22 Waveform equivalent processing block, 23 Data detection processing block, 24 Serial / parallel conversion block, 25 Signal separation processing block, 26 Control microcomputer block

Claims (14)

A signal transmission / reception system capable of transmitting a video signal from a signal transmission device to a signal reception device,
The signal transmission device is
Video signal generating means for generating a video signal;
Information insertion for inserting information on the format after switching and information on timing for switching into the blanking interval of the video signal generated by the signal generation unit based on a control signal for switching the format of the video signal to a different format Means,
Signal transmitting means for transmitting a video signal into which information is inserted by the information inserting means;
With
The signal receiving device is
Signal receiving means for receiving the video signal transmitted by the signal transmitting means;
Information extracting means for extracting information on the switched format and information on switching timing from the video signal received by the signal receiving means;
Reproduction switching means for switching video reproduction based on information on the format after switching taken out by the information extracting means and information on timing to switch;
A signal transmission / reception system comprising:   2. The signal transmission / reception system according to claim 1, wherein the video signal transmitted by the signal transmission means conforms to an SDI (Serial Digital Interface) standard.   2. The signal transmission / reception system according to claim 1, wherein the playback switching means mutes playback when switching video playback. The signal transmission device includes an audio signal generation means for generating an audio signal,
In the information insertion means, the video signal generated by the signal generation means is information relating to the audio signal format after switching and information relating to the switching timing based on a control signal for switching the format of the audio signal to a different format. In the blanking section, the information extracting means extracts information relating to the format of the audio signal after switching and information relating to the switching timing from the video signal received by the signal receiving means, and the reproduction switching means Then, based on the information regarding the format of the switched audio signal extracted by the information extracting means and the information regarding the switching timing, the reproduction is muted when switching the audio reproduction. Signal transmitting and receiving system 2 according. Video signal generating means for generating a video signal;
Information insertion for inserting information on the format after switching and information on timing for switching into the blanking interval of the video signal generated by the signal generation unit based on a control signal for switching the format of the video signal to a different format Means,
Signal transmitting means for transmitting a video signal into which information is inserted by the information inserting means;
A signal transmission device comprising:   6. The signal transmission apparatus according to claim 5, wherein the video signal transmitted by the signal transmission means conforms to an SDI (Serial Digital Interface) standard. Audio signal generating means for generating an audio signal;
In the information insertion means, the video signal generated by the signal generation means is information relating to the format of the audio signal after switching and information relating to the switching timing based on a control signal for switching the format of the audio signal to a different format. The signal transmitting apparatus according to claim 6, wherein the signal transmitting apparatus is inserted into a blanking section of Signal receiving means for receiving a video signal;
Information extracting means for extracting information relating to the format after switching and information relating to the switching timing from the video signal received by the signal receiving means;
Reproduction switching means for switching video reproduction based on information on the format after switching taken out by the information extracting means and information on timing to switch;
A signal receiving device.   9. The signal receiving apparatus according to claim 8, wherein the video signal received by the signal receiving means conforms to an SDI (Serial Digital Interface) standard.   9. The signal receiving apparatus according to claim 8, wherein the playback switching means mutes playback when switching video playback.   In the information extraction means, information related to the format of the audio signal after switching and information related to the switching timing are extracted from the video signal received by the signal reception means, and in the reproduction switching means, the information extraction means extracts the information. 10. The signal receiving apparatus according to claim 9, wherein the reproduction is muted when the audio reproduction is switched based on the information on the format of the audio signal after the switching and the information on the switching timing. A signal generating step for generating a video signal;
Information insertion for inserting information on the format after switching and information on timing for switching into the blanking interval of the video signal generated by the signal generation step based on a control signal for switching the format of the video signal to a different format Steps,
A signal transmission step of transmitting the video signal into which the information is inserted by the information insertion step;
A signal receiving step for receiving the video signal transmitted by the signal transmitting step;
An information extracting step for extracting information on the switched format and information on switching timing from the video signal received in the signal receiving step;
A reproduction switching step for switching video reproduction based on the information related to the switched format extracted by the information extraction means and the information related to the switching timing;
A signal transmission / reception method comprising: A signal generating step for generating a video signal;
An information insertion step of inserting information relating to the format after switching and information relating to the switching timing into a blanking interval of the video signal generated by the signal step based on a control signal for switching the format of the video signal to a different format. When,
A signal transmission step of transmitting the video signal into which the information is inserted by the information insertion step;
A signal transmission method comprising: A signal receiving step for receiving a video signal;
An information extracting step for extracting information relating to the format after switching and information relating to switching timing from the video signal received in the signal receiving step;
A reproduction switching step for switching video reproduction based on the information on the format after switching extracted in the information extraction step and the information on the switching timing;
A signal receiving method comprising:

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