JP2015167345A - Device and method for catv monitoring - Google Patents

Device and method for catv monitoring Download PDF

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JP2015167345A
JP2015167345A JP2014152462A JP2014152462A JP2015167345A JP 2015167345 A JP2015167345 A JP 2015167345A JP 2014152462 A JP2014152462 A JP 2014152462A JP 2014152462 A JP2014152462 A JP 2014152462A JP 2015167345 A JP2015167345 A JP 2015167345A
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video
means
step
program
monitoring
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毅 尾花
Takeshi Obana
毅 尾花
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ミハル通信株式会社
Miharu Communications Co Ltd
古河電気工業株式会社
Furukawa Electric Co Ltd:The
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Abstract

PROBLEM TO BE SOLVED: To improve reliability in the switchover of an N+M redundant configuration by objectively monitoring the final output of a head end.SOLUTION: A CATV monitoring device includes: selection means (TS DEMUX DESCR 14) for sequentially selecting a plurality of programs superposed on a carrier wave; demodulation means (MPEG-2 DECODER 15) for demodulating a program selected by the selection means; extraction means (video monitoring unit 17) for extracting a frame which configures a video from the program demodulated by the demodulation means; and detection means (resolution monitoring unit 17) for comparing all image data in at least two frames or partial image data having the same positional relationship belonging to the same program extracted by the extraction means in different timings, to detect an abnormality in the video.

Description

  The present invention relates to a CATV monitoring apparatus and a CATV monitoring method.

  For example, as disclosed in Patent Document 1, a conventional system for monitoring and switching to a spare machine in CATV sends its own abnormal state determined by the unit itself to the controller, and the spare machine is triggered by the information. It was an N + 1 redundant system that switches to.

JP-A-11-215150

  By the way, in the technique disclosed in Patent Document 1, only the abnormal state assumed in advance by the unit can be detected, and depending on the type of abnormal state, switching to the spare machine may not be performed normally. .

  The present invention has been made in view of the above points, and by using the CATV monitoring apparatus and CATV monitoring method according to the present invention to objectively monitor the final output of the head end, the reliability of N + M redundant configuration switching can be improved. The purpose is to improve the performance.

In order to solve the above-described problems, the present invention provides a CATV monitoring apparatus that monitors a CATV system that broadcasts a plurality of programs having audio and video on a carrier wave, the plurality of programs superimposed on the carrier wave. Selection means for selecting sequentially, demodulation means for demodulating a program selected by the selection means, extraction means for extracting a frame constituting the video from the program demodulated by the demodulation means, and the extraction means Detecting means for detecting an abnormality of the video by comparing all image data of at least two frames belonging to the same program extracted at timing or a part of image data having the same positional relationship. To do.
According to such a configuration, the reliability of N + M redundant configuration switching can be improved by objectively monitoring the final output of the head end.

In the invention, it is preferable that the detection unit has a difference value of a value reflecting each information of a plurality of pixels belonging to all image data of at least two frames or a part of image data having the same positional relationship. When it is less than the first threshold, it is determined that a freeze has occurred.
According to such a configuration, the freeze can be detected easily and efficiently.

According to the present invention, the detection means determines that a freeze has occurred when the difference value belonging to the same program is continuously less than the first predetermined threshold for a first predetermined time or longer. It is characterized by doing.
According to such a configuration, the freeze can be detected easily and efficiently, and the detection accuracy can be improved.

In the invention, it is preferable that the detection unit has a difference value of a value reflecting each information of a plurality of pixels belonging to all image data of at least two frames or a part of image data having the same positional relationship. When it is less than the first threshold and the value reflecting the luminance information of the pixel is less than the second threshold, it is determined that blackout has occurred.
According to such a configuration, blackout can be detected easily and efficiently.

In the invention, it is preferable that the detection unit has a value in which luminance information of the plurality of pixels belonging to the same program is reflected is less than a second predetermined threshold for a second predetermined time or longer. Is characterized by determining that a blackout has occurred.
According to such a configuration, blackout can be detected easily and efficiently, and detection accuracy can be improved.

Further, the present invention is characterized in that the extracting means extracts an I frame from a frame group included in the video of the program.
According to such a configuration, since the decoding process can be executed by using only the I frame, the decoding process can be executed more efficiently.

The present invention further includes storage means for storing all image data of the frame extracted by the extraction means or part of image data having the same positional relationship, and the detection means is stored in the storage means. The abnormality is detected by comparing the current image data and the image data extracted by the extracting means.
According to such a configuration, by storing videos of a plurality of programs in the storage means, it is possible to reliably detect an abnormality even when the number of programs is large.

Further, the present invention is characterized in that the extraction means extracts sound from the program, and the detection means detects presence or absence of sound abnormality from the signal level of the sound extracted by the extraction means. .
According to such a configuration, it is possible to detect not only video but also abnormal audio.

According to the present invention, the detecting means is a personal computer that realizes a function of detecting an abnormality of a video by comparing all image data of at least two frames or a part of image data having the same positional relationship by a program. It is characterized by being configured.
According to such a configuration, a part of the functions is realized by a personal computer, so that processing is performed at a high speed and the display form on the display is devised to reliably notify the occurrence of an abnormality to the monitor. be able to.

Further, the present invention is characterized in that a plurality of the demodulation means are provided, and the program selected by the selection means is sequentially assigned to the demodulation means for which demodulation processing has been completed and demodulated.
According to such a configuration, the processing can be efficiently allocated to the demodulating means to speed up the processing, and even when the demodulating means fails, it is possible to cope without adding any special processing.

In the present invention, the demodulation means has a descrambling unit for releasing the scramble process applied to the program, and has a plurality of cards storing scramble keys necessary for executing the descrambling. When a descrambling key request is made from the descrambling unit, the scrambling key is sequentially extracted from the card after the scrambling key extraction process is completed.
According to such a configuration, it is possible to speed up the processing by efficiently extracting the scramble key, and to deal with a card failure without adding any special processing.

According to another aspect of the present invention, there is provided a CATV monitoring method for monitoring a CATV system that broadcasts a plurality of programs having audio and video on a carrier wave, a selection step of sequentially selecting the plurality of programs superimposed on the carrier wave; A demodulation step for demodulating the program selected in the selection step, an extraction step for extracting a frame constituting the video from the program demodulated in the demodulation step, and the same extracted at different timings in the extraction step A detection step of detecting an abnormality of the video by comparing all image data of at least two frames belonging to the program or a part of the image data having the same positional relationship.
According to such a method, the reliability of N + M redundant configuration switching can be improved by objectively monitoring the final output of the head end.

  According to the present invention, the reliability of N + M redundant configuration switching can be improved by objectively monitoring the final output of the headend.

It is a system block diagram. It is a polling mode monitoring flow. It is an internal block diagram of a CATV monitoring apparatus. It is the structure of the conventional image monitoring system. This is the configuration of the monitoring system. It is an image monitoring process flow. It is a monitoring application. This is a monitoring target hierarchy display function. This is a monitoring target service still image display function. RF status display. TS hierarchy display. It is a block diagram which shows the structural example of 2nd Embodiment of this invention. It is a flowchart for demonstrating an example of the process performed in 2nd Embodiment shown in FIG. It is a flowchart for demonstrating the detail of step S14 shown in FIG. It is a flowchart for demonstrating the detail of step S15 shown in FIG. It is a figure which shows the deformation | transformation embodiment of this invention. It is a flowchart for demonstrating an example of the process performed in the polling management part shown in FIG. It is a flowchart for demonstrating an example of the process performed in the CAS card management part shown in FIG. It is a figure which shows the deformation | transformation embodiment of FIG. It is a figure which shows the deformation | transformation embodiment of FIG.

(A) Description of the First Embodiment This monitoring apparatus is a BS tramoji, a terrestrial digital tramoji, a QAM modulated wave output from a remax system, an OFDM modulated wave and FM output from a terrestrial digital broadcast pass-through system (including terrestrial digital independent broadcasting). The FM modulated wave output from the signal processor is sequentially monitored by polling.

In addition to monitoring the status of RF such as the modulation wave level, BER, and MER, and status of the demodulated transport stream, the status of the video signal (freeze, blackout) is also monitored at the same time, so abnormalities in the encoder and multiplexer It is a system that can also detect faults in which no change is seen in the RF state.
The single device can monitor the modulation state of the QAM modulated wave, OFDM modulated wave, and FM modulated wave.
In addition to the modulated wave status, it is possible to monitor the video status (freeze / blackout) of all services included in the carrier.

By using a plurality of monitoring units, the monitoring interval for each service can be shortened. For example, in the first embodiment, since four QAM monitoring units, two OFDM monitoring units, and two FM monitoring units are provided, the sequential monitoring interval by polling can be shortened. In order to detect a failure that can be recovered instantaneously, each monitoring circuit can be set to a constant monitoring mode by setting.
Although the initial setting of this monitoring device and the display of monitoring results are performed by application software that runs on a Windows (registered trademark) personal computer, even if the application software is not running due to a failure of the personal computer, etc. It is possible to continue.
N + M spare machine switching can be executed in cooperation with controller software such as a tramoji controller and SP controller.

  This apparatus monitors the state of modulated waves output from various headend apparatuses and the state of video and audio of services (programs) included therein. In addition to monitoring the signal level, it is possible to monitor the quality of modulation by demodulating a QAM or OFDM modulated signal and measuring BER, MER, etc. It is also possible to descramble the service (program) included in the demodulated TS and monitor the video state. Since these monitoring operations are performed by sequential monitoring by frequency polling using a plurality of monitoring units in the device, it is possible to monitor all modulated waves with a single device. By using a plurality of this apparatus, the monitoring interval can be shortened. When an abnormality is detected, a function that prevents erroneous detection of the abnormality is implemented by reconfirming the abnormality with another monitoring unit that has multiple systems in consideration of malfunction or failure of the monitoring unit.

In addition, by setting one of a plurality of monitoring circuits to be in a constant monitoring mode (multiple settings are possible), it is possible to observe a level and BER fluctuation in a short cycle. When this mode is set, the demodulated TS can be output from the TS output terminal of the apparatus main body, and the demodulated TS can be continuously output from the IP port using TS over IP.
The CATV monitoring device uses application software that runs on a Windows (registered trademark) PC to display the monitoring target settings and monitoring results. Even when the software is not running due to a PC failure or the like, the monitoring device alone Monitoring can be continued.

  This apparatus is provided with four QAM monitoring units, two OFDM monitoring units, and one FM monitoring unit. Each monitoring unit can be operated in a polling mode or a continuous monitoring mode. By monitoring the remaining carriers in a distributed manner by the monitoring unit that is not set to always monitor, the monitoring interval by polling is shortened.

The 4-carrier QAM monitoring unit, the 2-system OFDM monitoring unit, and the 2-system FM monitoring unit are efficiently used to monitor the set carriers to be monitored in order. The measurement time per carrier varies depending on the set monitoring item and the service (number of programs) included in one TS.
By setting one of a plurality of monitoring units mounted in the continuous monitoring mode, the set carrier state can be continuously monitored.

The status of the QAM modulated wave, OFDM modulated wave, and FM modulated wave transmitted from the CATV head end can be monitored by one apparatus. The state of all carriers set by sequential monitoring by polling is monitored in order. In order to shorten the monitoring interval, parallel monitoring is performed with four QAM monitoring units, two OFDM monitoring units, and two FM monitoring units. When an abnormality is detected, the polling operation is temporarily stopped, and the monitoring unit other than the monitoring unit that detected the abnormality is tuned again and the carrier that has detected the abnormality is reconfirmed (preventing malfunction of the monitoring unit).
Monitoring items QAM, OFDM, RF level, BER
・ MER
-Constellation FM-RF level-Silence detection The content of TS demodulated by the RF monitoring unit can be monitored.
TS monitoring item / TS SYNC
・ PAT (timeout, CRC check)
・ PMT (timeout, CRC check)
・ Video / audio ES (timeout)
・ Video / audio continuity counter check ・ ECM (timeout)
・ PCR (timeout / jitter simple measurement)
・ TOT (timeout ・ difference comparison with time acquired from NTP server)

This monitoring system realizes a simple video / audio anomaly detection function in order to minimize two-hour or more wave-breaking accidents that require reporting to the Ministry of Internal Affairs and Communications. Faults that do not appear in the deterioration of RF carrier characteristics, such as baseband system errors and encoder errors, are detected.
An abnormal state of video (not image quality) usually appears as the following symptoms.
A1: Block noise generation A2: Freeze state A3: Black state Among these, the abnormal state of A1 is considered to be caused by the deterioration of the RF signal due to rain attenuation or abnormal modulation state, and the RF monitoring unit lowers the carrier level, BER deterioration, etc. Is detected.
The abnormal states A2 and A3 are caused by an SDI transmission line abnormality from the program supply company to the head end device where the encoder is placed, a video server failure, an encoder failure, a multiplexing device failure, and the like. When these faults occur, there is a high possibility that they will not be directly related to the deterioration of the RF signal, so it cannot be detected only by monitoring the state of the RF signal. In this system, in all services (programs) output from the head end, the detection that the freeze state or the black state continues is detected by a single device.

In broadcast video, there are many scenes in which still images continue to flow for several tens of seconds, so it is very difficult to determine the freeze state in a short time. Since this system monitors a maximum of 200 programs (provisional) in order with one device, the monitoring interval for each service takes several minutes.
This system uses this time for image determination. In the apparatus, after the carrier to be monitored is demodulated, the image monitoring process operates in parallel with the RF state monitoring.

Device internal processing S111: PAT and PMT are acquired from the demodulated TS, and in the case of video / audio packets of services and scrambled services included therein, the ECM is extracted.
S112: The ECM is transferred to the CAS card, Ks (scramble key) is taken out, and the video / audio packet is unscrambled.
S113: Only the TS packet including the I frame arranged at the head of the GOP is extracted from the descrambled TS packet (the I frame can be decoded only with the I frame because of intra-frame coding).
S114: The voice packet cuts out a packet for one audio frame (1024 samples) including the AAU header.
S115: Information necessary for the monitoring application, such as service ID, PID, and time stamp, is added to the video packet including only the extracted I frame and the audio packet for one frame, and directed to the monitoring application using the UDP / FLUTE protocol. And send it out.

Monitoring application process S121: A TS file (only I frame) transmitted by UDP (assuming FLUTE protocol) is received.
S122: The video ES (I frame only) included therein is decoded and encoded into a JPEG file.
S123: The previous file of the service is read from the hard disk and JPEG decoded.
S124: An image obtained by decoding the I frame sent this time is compared with the previous image, and if there is a difference, it is determined that there is a difference, and if there is no difference (a difference error can be set to some extent), it is determined that the image is frozen. When it is determined that the image is frozen, the luminance level of the image is determined.
S125: Rewrite the still image of the corresponding service part of the multi-screen of the application, JPEG encode the image, add a time stamp, and save it on the hard disk as the next comparison file.

The stored JPEG file can be stored for 90 days, for example.
Depending on the processing speed of the application, the thread for image processing is operated in parallel.
The monitoring unit set to the continuous monitoring mode continuously monitors only a modulated wave having a specific frequency. The monitoring items are the same as those that can be monitored in the polling mode, but the following functions are enabled by setting the continuous mode.
TS output function device It is possible to output the demodulated TS in ASI format from the TS output terminal (BNC) mounted on the rear panel.
TS capture function The demodulated TS is always buffered in the memory, and TS data including the moment when abnormality is detected can be stored in the SDXC card.
TS over IP function One service out of the services included in the demodulated TS can be descrambled and transmitted to the monitoring application using TS over IP. The video can be confirmed using a software decoder on the surveillance application.

Coordination with various unit controllers C1: The IP address of the PC on which the various controllers are installed and the port number of each controller are set in the CATV monitoring device (maximum 3).
C2: When the CATV monitoring apparatus detects an abnormality, information including [abnormal frequency / abnormal content] is transmitted by UDP to the controller set as the notification destination controller.
At the same time, a Trap is issued to the SNMP manager.
C3: The controller that has received the abnormality notification determines whether the information is abnormal for the unit it is controlling, and if it is the corresponding unit, sets the spare machine to the abnormal frequency and receives the spare machine. Check if there are any abnormalities in the signal (is there any rain attenuation, pause, etc.).
C4: When the signal received by the spare machine is normal and the abnormal content is the spare machine switch target, the switch to the spare machine is executed.

Monitoring target setting T1: Transmission frequency T2: Modulation type (QAM / OFDM / FM)
T3: RF monitoring item setting T3-1: Monitoring item selection T3-2: Abnormal judgment threshold setting T4 TS monitoring item setting T4-1: Monitoring item selection T4-2: Abnormality judgment threshold setting T5: Image monitoring item setting T5-1 Target service selection T5-2: Freeze determination time setting T5-3: Black determination luminance level setting

Monitoring target hierarchy display function Information on carriers registered as monitoring targets can be displayed in a hierarchy.
D1: Network layer display A network can be displayed as a top layer.
D1-1: Terrestrial digital pass-through (including independent broadcasting)
D1-2: Terrestrial digital tramology D1-3: BS tramology D1-4: CATV multi-channel (Remax, JDS, JC-HITS)
D1-5: FM
D2: Clicking on the network at the top of the frequency layer display displays a list of carrier frequencies included in that network.
D3: Service layer display When the carrier frequency is clicked, the service ID and service name included in the carrier (TS) are displayed.

  A still image obtained by decoding an I frame sent from the monitoring device can be displayed. Each time image data is sent from the device, the still image of the corresponding service is rewritten. Also, waveform data obtained by decoding audio data (1024 samples per frame) is displayed below the image.

Clicking on the frequency in the network tree displays the RF status of the carrier and the status of the demodulated TS. In the case of terrestrial digital OFDM, in addition to constellation, it is also possible to display delay profiles and in-band frequency characteristics (selected by tabs).
Clicking on a frequency in the network tree displays the hierarchical state of the TS included in that carrier. Services included in the TS, video, audio, data, etc. PID, VerNo. Can be displayed.

(B) Description of Second Embodiment Next, a second embodiment of the present invention will be described. FIG. 12 is a block diagram showing a configuration example of the second embodiment of the present invention. As shown in this figure, the CATV monitoring apparatus 1 according to the second embodiment of the present invention includes an input terminal 10, an RF DIV 11, a QAM (Quadrature Amplitude Modulation) demodulator 12, an OFDM (Orthogonal Frequency Division Multiplexing) demodulator 13, TS (Transport Stream) DEMUX (Demultiplexing) DESCR (Descramble) 14, MPEG (Moving Picture Experts Group) 2 DECODER 15, Advanced Audio Coding (AAC) DECODER 16, Video monitoring unit 17, Audio monitoring unit 18, Video DAC (Digital to Analog Converter) ) 19, an audio DAC 20, a video output terminal 21, audio output terminals 22, 23, a CPU (Central Processing Unit) 24, and an Ethernet (registered trademark) 25. The TS DEMUX DESCR 14 has a C-CAS (Conditional Access System) card 30 and a B-CAS card 31.

  Here, the input terminal 10 inputs an RF signal output from the head end of the CATV. The RF DIV 11 receives an RF signal, distributes it into two, and supplies it to the QAM demodulator 12 and the OFDM demodulator 13.

  The QAM demodulator 12 QAM-demodulates the RF signal supplied from the RF DIV 11 to generate and output a TS (Transport Stream). The OFDM demodulator 13 performs OFDM demodulation on the RF signal supplied from the RF DIV 11 to generate and output a TS.

  The TS DEMUX DESCR 14 obtains the scramble key stored in the C-CAS card 30, and descrambles the CS digital broadcast TS based on the scramble key, and separates it into a video packet and an audio packet. The signals are supplied to MPEG2 DECODER 15 and AAC DECODER 16, respectively. Also, the TS DEMUX DESCR 14 acquires the scramble key stored in the B-CAS card 31, and based on this scramble key, descrambles the BS digital broadcast TS and separates it into a video packet and an audio packet. Are supplied to MPEG2 DECODER 15 and AAC DECODER 16, respectively.

  The MPEG2 DECODER 15 performs a decoding process based on MPEG2 on the video packet supplied from the TS DEMUX DESCR 14 and supplies the obtained video data to the video monitoring unit 17.

  The AAC DECODER 16 performs a decoding process based on AAC on the voice packet supplied from the TS DEMUX DESCR 14 and supplies the obtained voice data to the voice monitoring unit 18.

  The video monitoring unit 17 acquires an I frame included in the video data supplied from the MPEG2 DECODER 15. Here, the I (Intra) frame is one of the frames constituting the MPEG GOP (Group of Picture), and the P (Predictive) frame and B (Bidirectionally Predictive), which are other frames that also constitute the GOP. Unlike a frame, it is an independent frame encoded within a frame and can be decoded without the presence of other B and P frames. The image of a predetermined area of this I frame (all or a part of the I frame) is sampled and stored as image sampling data, and compared with the image sampling data of the same program stored in the past, It is determined whether or not out or freeze has occurred. If it has occurred, a warning is issued. Otherwise, similar processing is repeated.

  The voice monitoring unit 18 samples the voice data supplied from the AAC DECODER 16 and stores it as voice sampling data, and compares it with the voice sampling data of the same program stored in the past, and silent or mute that is abnormal in voice occurs. If it has occurred, a warning is issued. Otherwise, similar processing is repeated.

  The video DAC 19 converts the video data monitored by the video monitoring unit 17 into a video signal that is an analog signal, and outputs the video signal from the video output terminal 21. The video output terminal 21 is connected to a display, for example, and supplies a video signal output from the video DAC 19 to the display. The audio DAC 20 converts the audio data monitored by the audio monitoring unit 18 into an audio signal that is an analog signal and outputs the audio signal from the audio output terminals 22 and 23. The audio output terminals 22 and 23 are connected to a speaker through an amplifier, for example, and emit an audio signal output from the audio DAC 20 from the speaker.

  The CPU 24 controls each part of the apparatus and is connected to, for example, a personal computer (not shown) via the Ethernet (registered trademark) 25 and notifies the personal computer of the monitoring results of the video monitoring unit 17 and the audio monitoring unit 18.

(C) Description of Operation of Second Embodiment Next, the operation of the second embodiment will be described. In the following, after describing the operation principle of the second embodiment, detailed operations will be described with reference to the flowcharts shown in FIGS.

  When the CATV monitoring apparatus 1 starts operation, the CPU 24 controls the TS DEMUX DESCR 14 to select a signal having a predetermined frequency included in the RF signal. Since the RF signal includes signals having a plurality of frequencies as shown in FIG. 8, for example, the TS DEMUX DESCR 14 selects a signal having a predetermined frequency, and the desired signal included in the signal having the selected frequency is selected. These programs are descrambled by the scramble key stored in the C-CAS card 30 or the B-CAS card 31, and the video packet and the audio packet are separated and output.

  The MPEG2 DECODER 15 decodes the video packet supplied from the TS DEMUX DESCR 14 based on MPEG2 and outputs the obtained video data to the video monitoring unit 17. The AAC DECODER 16 decodes the voice packet supplied from the TS DEMUX DESCR 14 based on the AAC, and outputs the obtained voice data to the voice monitoring unit 18.

  The video monitoring unit 17 acquires an I frame included in the video data. The video monitoring unit 17 samples, for example, pixels of predetermined image data (all or part of the image data of the field) from the first field and the second field of the I frame and stores them in a memory (not shown), for example, a program (service ) Information such as ID, PID, and time stamp is attached and stored as image sampling data.

The video monitoring unit 17 acquires the image sampling data stored in the previous process and compares it with the image sampling data acquired this time. For example, the R, G, B plane pixel data constituting the image sampling data acquired this time is R1 ij , G1 ij , B1 ij , respectively, and the R, G, B plane pixel data of the stored image sampling data is Let R2 ij , G2 ij , and B2 ij respectively. Here, i and j indicate pixel positions x and y in the R, G, and B planes. For example, when the image of the R, G, B plane of the image sampling data is composed of nx × ny pixels in the horizontal and vertical directions, i and j are in the range of 1 ≦ i ≦ nx, 1 ≦ j ≦ ny. Is a variable that can take Then, the difference values ΔR ij , ΔG ij , ΔB ij of the pixels existing at positions i, j on the R, G, B plane are obtained by the following equations (1) to (3). Note that || indicates that the absolute value in parentheses is calculated. Each pixel is preferably 8 bits or 10 bits, but the present invention is not limited to the above values.

ΔR ij = | R1 ij −R2 ij | (1)
ΔG ij = | G1 ij −G2 ij | (2)
ΔB ij = | B1 ij −B2 ij | (3)

Then, an average value ΔAv ij of ΔR ij , ΔG ij , and ΔB ij is obtained based on the following formula (4).

ΔAv ij = (ΔR ij + ΔG ij + ΔB ij ) / 3 (4)

For example, 70% or more of ΔAv ij (1 ≦ i ≦ nx, 1 ≦ j ≦ ny) obtained by Expression (4) is less than the threshold Th1 (for example, the value “10” when expressed in 8 bits). It is determined that an abnormality has occurred. Here, ΔR ij , ΔG ij , and ΔB ij indicate the amount of change in the pixels at positions i and j in the previous sampling and the current sampling. That is, ΔR ij , ΔG ij , and ΔB ij do not become zero when the video has changed between the previous sampling and the current sampling (when the video is normal). However, for example, when the image is frozen, the video does not change, so ΔR ij , ΔG ij , and ΔB ij are 0 or a value close to 0. Also in the case of blackout, since the video hardly changes, these values are 0 or a value close to 0. Note that a value close to 0 is included because there are cases where the value does not become 0 due to the influence of noise or the like even when the image does not change at all.

In order to eliminate bias due to color, [Delta] R ij, .DELTA.G ij, the average value DerutaAv ij of .DELTA.B ij, the average value DerutaAv ij threshold Th1 (e.g., the value "10") pixel image sampling data is less than If it is 70% or more, it is determined as abnormal (freeze or blackout), otherwise it is determined as normal. Note that freeze and blackout are determined to be blackout when, for example, the luminance information of the pixels of the image sampling data is acquired, and 70% or more of the pixels whose luminance information is less than the threshold Th2 exist. In other cases, it can be distinguished by determining as freeze.

In the above embodiment, the abnormality is determined based on the difference values ΔR ij , ΔG ij , ΔB ij of the pixels existing at the positions i, j of the R, G, B planes. You may make it determine abnormality based on the numerical value obtained from data. For example, abnormality is determined for luminance data (Y), color difference data (Cb), and color difference data (Cr) based on the difference values ΔY ij , ΔCb ij , and ΔCr ij of pixels existing at positions i and j. Also good.

The voice monitoring unit 18 samples, for example, a predetermined number m (for example, 1024) of voice data from the voice data supplied from the AAC DECODER 16 at a predetermined interval (for example, 60 seconds when monitoring 100 services). Then, it is stored in a memory (not shown) as audio sampling data. The voice monitoring unit 18 determines whether or not the voice is normal based on the voice sampling data acquired by the current sampling. Specifically, the audio sampling data acquired this time is set as X1 i (i = 1 to m (m> 1)), and the total value X = Σ | X1 i | is obtained. Here, Σ indicates that calculation is performed for all of i = 1 to m, and indicates an operation such as taking the sum or average of all of i = 1 to n. || indicates that the absolute value in parentheses is calculated. Then, it is determined whether or not the value of X is less than a predetermined threshold Th3. If the value of X is less than the predetermined threshold Th3, it is determined that the silent state is set. When the value of X is 0, it is determined that the mute state is set. The larger the predetermined number m, the more reliably the silent state or the mute state can be detected. However, the larger the predetermined number m, the heavier the processing. It is desirable to set to.

  When an abnormality is detected by either the video monitoring unit 17 or the audio monitoring unit 18, the CPU 24 does not show information for identifying the program in which the abnormality has occurred via the Ethernet (registered trademark). Notify the personal computer. For example, the personal computer is notified of the occurrence of an abnormality through a screen shown in FIG.

  When monitoring of all programs having a predetermined frequency is completed, the same process is executed by changing the frequency. When monitoring for all frequencies is completed, the same processing is repeated after returning to the same frequency as the first. In order to perform monitoring for all frequencies, a time corresponding to the number of frequencies (for example, several minutes) is required. Since the video broadcast by CATV includes a still image that continues for a certain time (for example, several tens of seconds), for example, in order to accurately determine whether or not a freeze has occurred, a certain time is required. It is necessary to continue monitoring. For this reason, if a service of a specific frequency is continuously monitored for a certain time or longer, it takes a very long time to monitor all the services. However, in the second embodiment, it is necessary to monitor continuously for a long time by sequentially acquiring the video of each program by the polling operation, storing it in the memory, and comparing the previous video with the current video. Disappear.

  Next, a more detailed processing flow will be described with reference to FIGS. When the process shown in FIG. 13 is started, the following steps are executed.

  In step S10, the CPU 24 controls the TM DEMUX DSCR 14 to tune any one of a plurality of frequency signals included in the RF signal. For example, when signals having a plurality of frequencies as shown in FIG. 8 are included, as an example, tuning is performed in ascending order of frequency.

  In step S11, the CPU 24 controls the TM DEMUX DSCR 14 to acquire a PAT (Program Association Table) included in the TS of the selected frequency. Here, the PAT is a table that stores a list of programs included in the TS.

  In step S12, the CPU 24 controls the TM DEMUX DSCR 14 to acquire a PMT (Program Map Table). Here, the PMT is a table storing PIDs such as images and sounds included in a certain program. If PIDs such as images and sounds can be obtained from the PMT, the program can be reproduced by extracting TS packets with those PIDs.

  In step S13, the CPU 24 controls the TM DEMUX DSCR 14, acquires a scramble key from the C-CAS card 30 or the B-CAS card 31, and executes descrambling processing on a predetermined service using this key.

  In step S14, the CPU 24 executes a process of monitoring the video of the program (program) that has been descrambled by the process of step S13. Details of this processing will be described later with reference to FIG.

  In step S15, the CPU 24 executes a process of monitoring the sound of the program that has been descrambled by the process of step S13. Details of this processing will be described later with reference to FIG.

  In step S16, the CPU 24 determines whether or not the video and audio of the program to be monitored are normal based on the results of the processing in steps S14 and S15, and determines that the video and audio are normal (step S16). : Yes), the process proceeds to step S18, and otherwise (step S16: No), the process proceeds to step S17. For example, if it is determined that at least one of video and audio is abnormal, the process proceeds to step S17.

  In step S <b> 17, the CPU 24 notifies the occurrence of an abnormality to a personal computer (not shown) via, for example, the Ethernet (registered trademark) 25. More specifically, the CPU 24 transmits information for specifying a program in which an abnormality is detected and information indicating the type of abnormality (for example, freeze, blackout, silent, or mute) to the personal computer. As a result, the personal computer can specify the program in which the abnormality has occurred and the type of abnormality.

  In step S18, the CPU 24 determines whether or not monitoring for all the programs in the TS to be monitored has been completed, and determines that monitoring for all programs has not been completed (step S18: No). ), The process returns to step S12, and the same processing as described above is repeated. Otherwise (step S18: Yes), the process proceeds to step S19.

  In step S19, the CPU 24 determines whether or not to end the monitoring process. If it is determined to continue the monitoring process (step S19: No), the CPU 24 returns to step S10 and repeats the same process as described above. In other cases (step S19: Yes), the process ends.

  Through the above processing, a plurality of frequency signals included in the RF signal input from the input terminal 10 are sequentially selected, and the program video and audio included in each frequency signal are monitored, and normal If not, the occurrence of an abnormality is notified so that a plurality of programs can be monitored reliably.

  Next, details of the process shown in step S14 of FIG. 13 will be described with reference to FIG. When the process of FIG. 14 is started, the following steps are executed.

  In step S30, the video monitoring unit 17 acquires the I frame of the video included in the program descrambled in step S13 of FIG.

  In step S31, the video monitoring unit 17 decodes the I frame acquired in step S30. As a result, a still image is obtained.

  In step S32, the video monitoring unit 17 samples a plurality of pixels of an image in a predetermined area from the still image obtained in step S31. For example, when an image is composed of two fields, an image of a predetermined area is sampled from each of the first field and the second field. As a sampling place, there are a method of sampling an image of all regions, a method of sampling from a portion where the video changes frequently (for example, a region near the center of the screen), and the like. Further, at this time, the ratio of the pixels to be sampled with respect to the pixels of the image in all regions may be appropriately set according to the use environment or the like. As an example, it is preferable to sample 70% or more of the pixels of the image, and more preferably 90% or more of the pixels. However, the present invention is not limited to the above values. Absent.

  In step S33, the video monitoring unit 17 assigns an ID for specifying a frequency and a program to the image sampling data obtained in step S32 and stores it in the memory. For example, information such as a program (service) ID, PID, and time stamp is stored in the memory.

  In step S34, the video monitoring unit 17 acquires the image sampling data of the same frequency and the same program sampled and stored in the memory by the previous processing with reference to the ID described above.

In step S35, the video monitoring unit 17 calculates the difference values ΔR ij , ΔG ij , and ΔB ij of the R, G, and B planes of the image sampling data obtained in step S32 and the past image sampling data obtained in step S34. (1) with determined based on to (3), the average value DerutaAv ij based on equation (4). More specifically, when the image sampling data acquired in step S32 is R1 ij , G1 ij , B1 ij, and the image sampling data stored in the memory is R2 ij , G2 ij , B2 ij , The difference values ΔR ij , ΔG ij , and ΔB ij are obtained based on the equations (1) to (3), and the average value ΔAv ij is obtained based on the equation (4). Thereby, the average value ΔAv ij (1 ≦ i ≦ nx, 1 ≦ j ≦ ny) of all the pixels constituting the image sampling data can be obtained.

In step S36, the video monitoring unit 17 determines whether or not ΔAv ij obtained in step S35 is less than a predetermined threshold Th1 with respect to pixels of a% or more, and determines that it is satisfied (step S36). : Yes), the process proceeds to step S38, and otherwise (step S36: No), the process proceeds to step S37. More specifically, for example, if ΔAv ij <10 is established in 70% or more of the entire pixels, the process proceeds to step S38, and otherwise, the process proceeds to step S37. More preferably, when ΔAv ij <3 is established at 90% or more of the whole, the process may proceed to step S38, and otherwise, the process may proceed to step S37.

  In step S37, the video monitoring unit 17 determines that the video of the monitoring target program is normal.

In step S38, the video monitoring unit 17 acquires a plurality of luminance data Y ij (1 ≦ i ≦ nx, 1 ≦ j ≦ ny) from the image sampling data. Here, the luminance indicates the degree of brightness of the image. For example, when blackout occurs, the luminance data is 0 or a value close to 0 in many pixels.

In step S39, the video monitoring unit 17 determines whether or not the plurality of luminance data Y ij acquired in step S38 is less than the predetermined threshold value Th2 is equal to or greater than b% of all pixels, and is determined to be satisfied. If so (step S39: Yes), the process proceeds to step S40. Otherwise (step S39: No), the process proceeds to step S41. More specifically, it can be determined whether or not Y ij <10 is satisfied in 70% or more of the whole. More preferably, it may be determined whether or not Y ij <3 is satisfied in 90% or more of the whole. The determination may be made based on past image sampling data stored in the memory.

In step S40, the video monitoring unit 17 establishes that the difference value ΔAv ij <Th1 of the image sampling data sampled at a predetermined time is equal to or greater than a% of all the pixels, and the luminance data Y ij <Th2 is all Since it is established at b% or more of the pixels, it is determined that blackout (a phenomenon in which the screen turns black) has occurred, and the process returns (returns) to the processing of FIG.

In step S41, the video monitoring unit 17 establishes that the difference value ΔAv ij <Th1 of the image sampling data sampled at a predetermined time is equal to or greater than a% of all pixels, and the luminance data Y ij <Th2 is all Since it does not hold at more than b% of the pixels, it is determined that a freeze (a phenomenon in which the same image is continuously displayed) has occurred, and the processing returns to (returns to) the processing in FIG.

  According to the above process, it is possible to detect the presence or absence of an abnormality occurring in the video of the program to be monitored.

  In addition, about the program by which the abnormality of the image | video was detected in step S40 or S41, it is made to monitor a video again after predetermined time (for example, 30 second) progress, or every progress, and the abnormality detection of the image | video several times is carried out, It may be determined that an abnormality has occurred in the video of the program. With such a configuration, erroneous determination of abnormality can be reduced.

  Note that when monitoring the sequential program by polling operation, if the number of programs to be monitored is small, the polling interval will be shortened, so the video that has not been intentionally changed or has little change among the programs. May erroneously determine that an abnormality has occurred. In such a case, for example, if an abnormality is detected in video monitoring after a predetermined time (for example, 60 seconds) has elapsed since the detection of the video abnormality in the same program, It may be determined that an abnormality such as blackout has occurred. By adopting such a configuration, it is possible to reduce erroneous determination of abnormality, particularly when the number of programs to be monitored is small.

  Next, details of the process shown in step S15 of FIG. 13 will be described with reference to FIG. When the process of FIG. 15 is started, the following steps are executed.

  In step S50, the voice monitoring unit 18 acquires voice data to be monitored.

  In step S51, the voice monitoring unit 18 decodes the voice data acquired in step S50.

  In step S52, the voice monitoring unit 18 samples a predetermined number of data from the voice data obtained by the decoding in step S51. At this time, for example, 1024 samples per one ADTS (Audio Data Transport Stream) can be acquired by one decoding.

  Further, a predetermined number (for example, 1024) of voices in a state of jumping at predetermined intervals (for example, 60 seconds) may be acquired from continuous sound data by sampling. Note that the reason for sampling at a predetermined interval is to prevent sampling of such silent portions because there may be silent portions in the voice.

  In step S53, the voice monitoring unit 18 assigns an ID for specifying a frequency and a program to the voice data acquired in step S52 and stores it in the memory. For example, information such as a program (service) ID, PID, and time stamp is stored in the memory.

In step S54, the voice monitoring unit 18 determines whether or not the total value of the voice data obtained in step S52 is less than a predetermined threshold Th3, and determines that it is less than the threshold Th3 (step S54: Yes). The process proceeds to step S56, and otherwise (step S54: No), the process proceeds to step S55. More specifically, the audio sampling data obtained in step S52 is set as X1 i (i = 1 to m (m> 1, m = 1024 in the present embodiment)), and the total value X = Σ | X1 i | is obtained. . Here, as in the case described above, Σ indicates that calculation is performed for all i = 1 to m, and || indicates that the absolute value in parentheses is calculated. Then, it is determined whether or not the value of X is less than a predetermined threshold Th3. If it is less than the threshold Th3, the process proceeds to step S56. Note that the determination may also be made using the audio data stored in the memory in step S53. For example, the audio sampling data stored in step S53 is set to X2 i (i = 1 to m (m> 1)), and a total value X = Σ | X1 i | + | X2 i | is obtained, and based on this total value X You may make it judge.

  In step S55, the voice monitoring unit 18 determines that the voice is normal, and returns (returns) to the process illustrated in FIG.

In step S56, the voice monitoring unit 18 determines whether all of the voice data or the total value is 0. If all of the voice data or the total value is 0 (step S56: Yes), step S57 is performed. In other cases (step S56: No), the process proceeds to step S58. More specifically, for example, when the total value X = Σ | X1 i | obtained in step S54 is 0, the determination is Yes and the process proceeds to step S57.

  In step S57, the voice monitoring unit 18 determines that mute, which is a silent state, has occurred, and returns (returns) to the process shown in FIG.

  In step S58, the voice monitoring unit 18 determines that silent, which is a weak sound, has occurred, and returns (returns) to the process illustrated in FIG.

  According to the processing shown in FIG. 15, it is possible to detect an abnormality in the sound included in each program.

  In addition, about the program in which the audio | voice abnormality was detected in step S57 or S58, it is made to monitor an audio | voice again after predetermined time (for example, 30 second) progress, or every progress, and by detecting abnormality of an audio | voice several times, It may be determined that an abnormality has occurred in the sound of the program. With such a configuration, erroneous determination of abnormality can be reduced.

  Note that when monitoring programs sequentially by polling operation, if the number of programs to be monitored is small, the polling interval will be shortened. It may be erroneously determined that an abnormality has occurred. In such a case, for example, in the same program, when an abnormality is detected even in audio monitoring after a predetermined time (for example, 60 seconds) has elapsed since the detection of the audio abnormality, It may be determined that an abnormality such as a weak sound has occurred. By adopting such a configuration, it is possible to reduce erroneous determination of abnormality, particularly when the number of programs to be monitored is small.

  In the above configuration, for example, for a program in which an abnormality is detected, the detection result of the abnormality and the determined time may be stored. More specifically, for example, step S53 is omitted, and the abnormality detection result such as silent or mute and the time when the abnormality is detected are stored together with the ID for the program in which the abnormality is detected in step S57 or S58. By adopting such a configuration, it is possible to perform voice monitoring of a program in which an abnormality is detected based on the storage, and to reduce erroneous determination of abnormality.

  As described above, according to the second embodiment of the present invention, the images included in the program included in the RF signal are sequentially acquired, decoded, and stored in the memory. Then, freezes and blackouts are detected by comparing the previously stored video with the current video. For this reason, when detecting a freeze, it is not necessary to continuously monitor a specific program, so that the monitoring time can be shortened.

  In addition, since the I frame of the video is selected and used, it can be decoded independently as compared with the P and B frames, so that the processing load can be reduced. Further, since the I frame can be decoded by, for example, the same processing as JPEG, the hardware configuration of the video monitoring unit 17 can be simplified. In addition, since not all of the video is stored, but a part of the video is sampled and stored, the required storage area of the memory can be reduced.

  Further, since the voice is sampled and monitored, it is possible to prevent erroneous determination from being caused by a partial silent part.

(E) Description of Modified Embodiment Each of the above embodiments is an example, and it is needless to say that the present invention is not limited to the case described above. For example, in the second embodiment shown in FIG. 12, video and audio tuning, descrambling, decoding, and monitoring are executed by the same hardware, but these may be executed by different hardware. Good. For example, the process up to descrambling is executed by the same hardware, and the obtained video and audio are transferred to other hardware (for example, a personal computer). Audio may be monitored. Further, it may be divided into three or more hardware.

  Further, a part or all of the configuration shown in the second embodiment shown in FIG. 12 may be provided in plural, and video and audio may be monitored in parallel by these multiple configurations. According to such an embodiment, since the time required for monitoring can be shortened, an abnormality can be detected in a short time. FIG. 16 shows a specific configuration example in the case where a plurality of digital broadcast demodulation units and CAS cards are provided. 16 includes an input terminal 110, an RF distribution unit 111, digital broadcast demodulation units 112-1 to 112-3, ECM extraction units 113-1 to 113-3, descrambling units 114-1 to 114-3, It has a monitoring unit 115, a control unit 120, and CAS cards 130-1 to 130-3. The control unit 120 includes tuner control units 121-1 to 121-3, a polling management unit 122, a CAS card management unit 123, and card control units 124-1 to 124-3.

  Here, the input terminal 110 inputs an RF signal output from the head end of the CATV. The RF distribution unit 111 receives an RF signal, distributes it into three, and supplies them to the digital broadcast demodulation units 112-1 to 112-3, respectively. The digital broadcast demodulation units 112-1 to 112-3 select signals of predetermined frequencies (channels) designated by the tuner control units 121-1 to 121-3 from the RF signals supplied from the RF distribution unit 111. , QAM demodulation or OFDM demodulation to generate and output TS.

  The ECM extraction units 113-1 to 113-3 analyze the PAT and PMT included in the demodulated transport stream, extract ECM data necessary for descrambling, and supply the ECM data to the CAS card management unit 123. The descrambling units 114-1 to 114-3 execute descrambling processing based on the scramble key supplied from the CAS card management unit 123. The monitoring unit 115 monitors the stream that has been descrambled by the descrambling units 114-1 to 114-3. The control unit 120 includes digital broadcast demodulation units 112-1 to 112-3, ECM extraction units 113-1 to 113-3, descrambling units 114-1 to 114-3, and CAS cards 130-1 to 130-3. Control etc. Here, the tuner control units 121-1 to 121-3 control the digital broadcast demodulation units 112-1 to 112-3 in order to demodulate the channel (frequency) designated by the polling management unit 122. The polling management unit 122 efficiently demodulates a plurality of channels by controlling the tuner control units 121-1 to 121-3 and appropriately selecting a frequency to be demodulated by the digital broadcast demodulation units 112-1 to 112-3. . The CAS card management unit 123 supplies the ECM data extracted by the ECM extraction units 113-1 to 113-3 to the CAS cards 130-1 to 130-3 via the card control units 124-1 to 124-3. The scramble key is acquired and supplied to the descrambling units 114-1 to 114-3. The card control units 124-1 to 124-3 supply the ECM data supplied from the CAS card management unit 123 to the CAS cards 130-1 to 130-3, receive scramble keys, and supply them to the CAS card management unit 123. . When the ECM data is supplied, the CAS cards 130-1 to 130-3 read and supply the stored scramble key.

  Next, the operation of the embodiment shown in FIG. 16 will be described. In the embodiment illustrated in FIG. 16, the polling management unit 122 sequentially assigns channels to be monitored to the digital broadcast demodulation units 112-1 to 112-3 that have been processed and are in an empty state. For example, when monitoring in the order of CH1 to CH6, first, CH1 to CH3 are respectively assigned to the digital broadcast demodulation units 112-1 to 112-3. When the processing of the digital broadcast demodulator 112-3 is completed first, CH4 is assigned to the digital broadcast demodulator 112-3. Subsequently, when the process of the digital broadcast demodulator 112-2 is completed, CH5 is assigned to the digital broadcast demodulator 112-2. Next, when the process of the digital broadcast demodulator 112-1 is completed, the digital broadcast is demodulated. CH6 is assigned to the demodulator 112-1. In this way, by sequentially assigning channels to the digital broadcast demodulation units 112-1 to 112-3 in which processing vacancies have occurred, for example, channels assigned to the digital broadcast demodulation units 112-1 to 112-3 Compared with the case where the signal is fixed, the processing speed can be increased by preventing the digital broadcast demodulation units 112-1 to 112-3 from becoming empty. In addition, for example, even when any of the digital broadcast demodulation units 112-1 to 112-3 fails, by performing the same processing excluding the failed digital broadcast demodulation unit, Can be handled without a special control program. Furthermore, when an abnormality in the program is detected, the detection accuracy can be improved by checking again with another digital broadcast demodulator.

  Further, the scramble key can be extracted from the CAS cards 130-1 to 130-3 by the same processing. More specifically, when the ECM data is extracted by any one of the ECM extraction units 113-1 to 113-3 and supplied to the CAS card management unit 123, the CAS card management unit 123 causes the CAS cards 130-1 to 130. -3, the scramble key is acquired by supplying ECM data to the vacant CAS cards 130-1 to 130-3 that are not in the process of extracting the scramble key. According to such a process, for example, the process is distributed as compared with the case where the CAS cards 130-1 to 130-3 are exclusively assigned to the descramble units 114-1 to 114-3. In addition, it is possible to realize a high speed, and even when the CAS cards 130-1 to 130-3 break down, it is possible to easily cope with them without using a special processing program.

  Next, detailed operations of the embodiment shown in FIG. 16 will be described with reference to FIGS. 17 and 18. FIG. 17 is a flowchart for explaining an example of processing executed in the polling management unit 122 shown in FIG. When the flowchart shown in FIG. 17 is started, the following steps are executed.

  In step S70, the polling management unit 122 determines a frequency (channel) to be monitored. For example, when monitoring CH10 to CH20, CH10 is selected as the CH to be monitored.

  In step S71, the polling management unit 122 makes an inquiry to the tuner control units 121-1 to 121-3, and determines whether there is a digital broadcast demodulation unit that is in an empty state after the demodulation process is completed. If it is determined that it is present (step S71: Yes), the process proceeds to step S72. Otherwise (step S71: No), the same process is repeated. For example, if the digital broadcast demodulation unit 112-2 is in an empty state, the determination is Yes and the process proceeds to step S72.

  In step S72, the polling manager 122 assigns the frequency determined in step S70 to the tuner controller that manages the digital broadcast demodulator determined to be free in step S71. For example, if it is determined in step S71 that the digital broadcast demodulation unit 112-2 is free, the CH10 frequency determined in step S70 is assigned.

  In step S73, it is determined whether or not the process is to be ended. If it is determined that the process is not to be ended (step S73: No), the process returns to step S70 and the same process as described above is repeated. In step S73: Yes, the process ends.

  According to the above processing, it is possible to assign the demodulation processing to the digital broadcast demodulating unit which has been vacated after the processing.

  Next, processing executed in the CAS card management unit 123 shown in FIG. 16 will be described with reference to FIG. When the flowchart shown in FIG. 18 is started, the following steps are executed.

  In step S90, the CAS card management unit 123 determines whether or not ECM data has been extracted by the ECM extraction units 113-1 to 113-3. If it is determined that the ECM data has been extracted (step S90: Yes), step S91 is performed. In other cases (step S90: No), the same processing is repeated. For example, if the ECM data is extracted by the ECM extraction unit 113-1, the determination is Yes and the process proceeds to step S91.

  In step S91, the CAS card management unit 123 makes an inquiry to the card control units 124-1 to 124-3, and determines whether or not there is a vacant CAS card that is not executing the scramble key extraction process. If it is determined that it exists (step S91: Yes), the process proceeds to step S92. Otherwise (step S91: No), the same process is repeated. For example, if the CAS card 130-1 is empty, it is determined Yes and the process proceeds to step S92.

  In step S92, the CAS card management unit 123 supplies the ECM data acquired in step S90 to the CAS card determined to be empty in step S91. For example, when the CAS card 130-1 is in an empty state, the ECM data acquired by the ECM extraction unit 113-1 in step S90 is supplied to the card control unit 124-1.

  In step S93, the CAS card management unit 123 acquires a scramble key from the CAS card that has supplied the ECM data in step S92. For example, in this example, a scramble key is acquired from the CAS card 130-1 via the card control unit 124-1.

  In step S94, the CAS card management unit 123 supplies the scramble key acquired in step S93 to the descrambling unit corresponding to the ECM extraction unit that extracted the ECM data. Thereby, the descrambling process is executed in the descrambling unit. In this example, the scramble key is supplied to the descrambling unit 114-1 corresponding to the ECM extraction unit 113-1 that has extracted the ECM data.

  In step S95, it is determined whether or not to end the process. If it is determined not to end the process (step S95: No), the process returns to step S90 and the same process as described above is repeated. In (Step S95: Yes), the process ends.

  According to the above process, the scramble key can be requested to be extracted from the CAS card that is in an empty state after the process is completed.

  In the processing shown in FIG. 13, the case of tuning in ascending order of frequency has been described as an example. However, for example, the order of increasing frequency may be used, or a predetermined order (for example, high importance) may be used. You may make it tune in order. Further, when the occurrence of an abnormality is detected, the frequency may be preferentially monitored.

  In the process shown in FIG. 14, the previous and current two videos are compared. However, for example, three or more videos may be compared and determined. According to such a configuration, although the time required for detection becomes longer, an abnormality can be detected more accurately.

  In the processing shown in FIG. 14, the blackout is determined based on the luminance data. For example, in the case of RGB data, the blackout is performed when all the RGB data or the total value is substantially zero. May be determined. That is, it is only necessary to determine from the data that the entire image is black.

Further, in the embodiment shown in FIG. 14, it is determined that there is an abnormality when there are a% or more pixels where ΔAv ij <Th1 is satisfied, and there is black when there are b% or more pixels where Y ij <Th2 is satisfied. Although it is determined to be out, optimum values can be set for the values of Th1 and a% and Th2 and b% according to the device to be used, the purpose of use of the user, and the like. In addition, the ratio of the pixels for which ΔAv ij <Th1 is satisfied or the pixels for which Y ij <Th2 is satisfied is the ratio of all the image data constituting the frame to the pixels of the image, for example, a portion having a lot of motion (for example, The pixel of the image data near the center of the video may be determined as a target. Further, instead of determining each pixel, for example, ΔR ij , ΔG ij , and ΔB ij of all the target pixels are cumulatively added, and the obtained value is compared with the threshold value for determination. Also good. More specifically, ΔT = Σ (ΔR ij + ΔG ij + ΔB ij ) may be calculated, and the obtained ΔT may be compared with a predetermined threshold Th4. Of course, the same for Y ij, the motion is large portion in the video (e.g., near the center of the image) or so as to determine the target pixel regions, obtained by cumulatively adding the Y ij values May be compared with a threshold Th5. In addition, as the calculation for obtaining ΔR ij , ΔG ij , and ΔB ij , subtraction is used as shown in equations (1) to (3), but it is only necessary to detect the presence or absence of data change. (For example, exclusive OR) may be used. In the above embodiment, the determination is made by using all the R, G, and B planes. However, for example, the determination can be made by using at least one of them. For example, the determination may be made using any one of R, G, and B or any combination of these two. Further, instead of using R, G, and B data, for example, luminance data (Y), color difference data (Cb), color difference data (Cr), or the like may be used.

  Further, in the process shown in FIG. 15, the abnormality is determined from the sound sampling data only for the current time, but the sound abnormality is determined from the sound sampling data for the previous time and the current time, or for three times. The determination may be made from the above audio sampling data.

  In the second embodiment, only the abnormality is detected. However, when an abnormality is detected, the active system and the standby system of the multiplexed head end may be switched.

  2 and 6, the stream descrambled in the monitoring device is transferred to the monitoring application by UDP / RTP. However, as shown in FIGS. 19 and 20, file delivery in the IP multicast environment is performed. It may be transferred to the monitoring application via the IP network by the UDP / FLUTE protocol. According to such a configuration, an arbitrary file can be transmitted. More specifically, in FIG. 19, an image monitoring file is generated from the separated I picture and audio packet, and this file is packetized based on the FLUTE protocol and transmitted to the monitoring application via the IP network.

  In the second embodiment, the video of each program is sequentially acquired and stored in the memory, and the abnormality is detected by comparing with the previous video. However, the video stored in the memory before this time is used. You may make it compare with.

  In the second embodiment, the freeze state, the blackout state, the silent state, and the mute state are detected. However, an alarm may be issued when these states are detected. With this configuration, the administrator of the CATV system can quickly detect an abnormality. A configuration may be adopted in which it is determined that a broadcast accident has occurred when either the freeze state or the blackout state and either the silent state or the mute state are detected at the same time, and an alarm is issued. With such a configuration, it is possible to reduce false alarm occurrences, since it reduces the misjudgment of the occurrence of a broadcast accident and at the same time issues an alarm only when an abnormality is detected in the video and audio at the same time. .

  Further, when an abnormality is detected, the state may be notified to the SNMP manager by the SNMP protocol.

1 CATV monitoring device 10 Input terminal 11 RF DIV
12 QAM demodulator 13 OFDM demodulator 14 TS DEMUX DESCR
15 MPEG2 DECODER
16 AAC DECODER
17 Video monitoring unit 18 Audio monitoring unit 19 Video DAC
20 Audio DAC
21 Video output terminal 22, 23 Audio output terminal 24 CPU
25 Ethernet (registered trademark)
30 C-CAS Card 31 B-CAS Card 110 Input Terminal 111 RF Distribution Unit 112-1 to 112-3 Digital Broadcast Demodulation Unit 113-1 to 113-3 ECM Extraction Unit 114-1 to 114-3 Descramble Unit 115 Monitoring Unit 120 control unit 121-1 to 121-3 tuner control unit 122 polling management unit 123 CAS card management unit 124-1 to 124-3 card control unit 130-1 to 130-3 CAS card

Claims (12)

  1. In a CATV monitoring apparatus that monitors a CATV system that broadcasts a plurality of programs having audio and video superimposed on a carrier wave,
    Selecting means for sequentially selecting the plurality of programs superimposed on the carrier;
    Demodulating means for demodulating the program selected by the selecting means;
    Extraction means for extracting frames constituting the video from the program demodulated by the demodulation means;
    Detecting means for detecting abnormality of the video by comparing all image data of at least two frames belonging to the same program extracted at different timings by the extracting means or a part of image data having the same positional relationship;
    A CATV monitoring apparatus characterized by comprising:
  2.   The detection means has a difference value of a value reflecting each information of a plurality of pixels belonging to all of the image data of at least two frames or a part of the image data having the same positional relationship being less than the first threshold value. 2. The CATV monitoring apparatus according to claim 1, wherein it is determined that a freeze has occurred in some cases.
  3.   The detection means determines that a freeze has occurred when the difference value belonging to the same program is continuously less than the first predetermined threshold for a first predetermined time or longer. The CATV monitoring apparatus according to claim 2.
  4.   The detection unit is configured such that a difference value of a value reflecting each information of a plurality of pixels belonging to all image data of at least two frames or a part of image data having the same positional relationship is less than the first threshold value. 4. The CATV monitoring apparatus according to claim 2, further comprising: determining that a blackout has occurred when a value reflecting luminance information of the pixel is less than a second threshold value. 5.
  5.   The detection means generates a blackout when the value reflecting the luminance information of the plurality of pixels belonging to the same program is less than a second predetermined threshold for a second predetermined time or longer. The CATV monitoring apparatus according to claim 4, wherein the CATV monitoring apparatus is determined to be present.
  6.   The CATV monitoring apparatus according to claim 1, wherein the extraction unit extracts an I frame from a group of frames included in the video of the program.
  7. Storage means for storing all the image data of the frame extracted by the extraction means or a part of the image data having the same positional relationship;
    The detection means detects an abnormality by comparing the image data stored in the storage means with the image data extracted by the extraction means;
    The CATV monitoring apparatus according to any one of claims 1 to 6, wherein
  8. The extraction means extracts voice from the program,
    The detecting means detects the presence or absence of a sound abnormality from the signal level of the sound extracted by the extracting means;
    The CATV monitoring apparatus according to any one of claims 1 to 7, wherein
  9.   The detection means is constituted by a personal computer that realizes a function of detecting an abnormality of a video by comparing all image data of at least two frames or a part of image data having the same positional relationship by a program. The CATV monitoring apparatus according to any one of claims 1 to 8.
  10.   10. The method according to claim 1, comprising a plurality of the demodulation means, wherein the program selected by the selection means is sequentially assigned to the demodulation means for which demodulation processing has been completed and demodulated. CATV monitoring device.
  11. The demodulation means has a descrambling unit for releasing the scramble process applied to the program,
    When there are a plurality of cards storing scramble keys necessary for executing the descrambling, and when a descrambling key request is made from the descrambling unit, a scrambling key is extracted from the card after the scrambling key extraction process is completed. The CATV monitoring apparatus according to any one of claims 1 to 10, wherein the CATV monitoring apparatus is sequentially taken out.
  12. In a CATV monitoring method for monitoring a CATV system that broadcasts a plurality of programs having audio and video superimposed on a carrier wave,
    A selection step of sequentially selecting the plurality of programs superimposed on the carrier wave;
    A demodulation step for demodulating the program selected in the selection step;
    An extraction step of extracting frames constituting the video from the program demodulated in the demodulation step;
    A detection step of detecting an abnormality of the video by comparing all image data of at least two frames belonging to the same program extracted at different timings in the extraction step or a part of image data having the same positional relationship;
    A CATV monitoring method comprising:
JP2014152462A 2014-02-14 2014-07-27 Device and method for catv monitoring Pending JP2015167345A (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0946733A (en) * 1995-07-25 1997-02-14 Nippon Hoso Kyokai <Nhk> Video automatic monitoring device
JP2001339702A (en) * 2000-05-30 2001-12-07 Maspro Denkoh Corp Head-end for catv system
JP2003204562A (en) * 2001-07-19 2003-07-18 Kdd Media Will Corp Signal monitoring system
JP2004260308A (en) * 2003-02-24 2004-09-16 Sony Corp Channel selector and channel selection method
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