JP3109439B2 - Anomaly detection system for multimedia communication terminals - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multimedia communication terminal device for reproducing video data transmitted via a communication line, and more particularly to a multimedia communication device for detecting an abnormality occurring during video reproduction. The present invention relates to a terminal device abnormality detection system.

[0002]

2. Description of the Related Art With the diversification of personal or business requirements for image information, image reception services using communication lines such as cable television (CATV) have become widespread. In particular, in the communication system for image information using these communication lines, the technical development of an interactive television service called VOD (Video On Demand: television on demand) is active.

FIG. 9 shows an outline of a CATV system disclosed in Japanese Patent Application Laid-Open No. 4-324784. This system is for realizing a video service according to a request with a simple configuration. In this system, a recording medium or recording device for supplying and controlling the supply of multimedia, called a head-end device 11, is connected to one end of a transmission line 12, and the other end is installed in each subscriber's home. Connected to a set-top box (STB) 13. The set-top box 13 is a multimedia communication terminal device, and is connected to a television device or a television receiver 14 having a display and an interface.
The set-top box 13 has a channel selection mechanism (S
CS) 15 are arranged.

In the proposed CATV system, when a subscriber designates a specific television program in a specific time zone, a provider of the head end device 11 remotely controls a switching device (not shown) arranged at each subscriber position. Control to tune the set-top box 13 corresponding to that particular channel. By operating the channel selection mechanism 15 of the set-top box 13, the subscriber can watch a desired program on a specific television channel. Such systems are being developed in various fields, and are particularly expected to be used for entertainment and education.

[0005] In such a system, even if a device other than the multimedia communication terminal device as the user device is operating normally, an abnormality may occur in the multimedia communication terminal device due to an unexpected failure. . Therefore,
There have been proposals for detecting such abnormalities.
This includes an apparatus that detects an abnormality of an apparatus from an abnormality in a reproduced image, and an apparatus that determines an abnormality of an apparatus from an operation of software.

In JP-A-63-45698, an abnormality is detected by the former method. That is, in this proposal, one image captured from a moving image is subjected to A / D conversion (analog-to-digital conversion), and A / D conversion of an image similarly captured 0.5 to 1 second before this is performed. Compare the luminance with the later one. At this time, the luminance is compared at a certain level or higher with a threshold. In addition, before and after 2
Since it may not be possible to make an accurate judgment using only the screen,
During a certain period of time, similar comparison between two screens is continuously performed. As a result, when it is determined that no change in luminance is observed between the two screens in the luminance comparison during the predetermined time, it is determined that the multimedia communication terminal apparatus is abnormal.

[0007] Japanese Patent Application Laid-Open No. S60-51141 proposes, as the latter proposal, an abnormality of the apparatus from the operation of software. In this proposal, a software runaway monitoring program operated by a certain low-priority interrupt pulse is provided separately from the main program. When the software runaway monitoring program ends normally, an operation check pulse is generated, and an operation check pulse counter for counting operation check pulses counts the number of generated pulses. If the software runaway monitoring program does not end normally, no operation confirmation pulse will be generated. In this proposal, interrupts are made at fixed intervals, and the number of interrupts and the number of generated pulses counted by the operation confirmation pulse counter Compare with If the result satisfies a certain condition, it is determined that the software is out of control, and an abnormality of the multimedia communication terminal device is detected.

[0008]

In such a conventionally proposed abnormality detection system, two screens are continuously compared for a fixed time, or a software runaway monitoring program is periodically executed. In this case, the operation confirmation pulse is checked by using the terminal device. Therefore, it is very difficult to apply the device to a multimedia communication terminal device and incorporate them into the device because of the specialty of the device and the system scale. In addition, even if an abnormality is detected, there are some abnormalities that are not particularly noticeable to the user as a user, and it is often troublesome for the user to deal with them one by one.

[0009] An object of the present invention is to provide a multimedia communication terminal device that can reliably detect anomalies when the display of an image sent from the transmission side is stopped in consideration of an interface with a user who is a user. An object of the present invention is to provide an abnormality detection system for a multimedia communication terminal device that is frequently performed.

[0010]

According to the first aspect of the present invention, there are provided (a) video data decoding means for decoding video data transmitted via a communication line, and (b) video data decoding means for decoding the video data. A decode counter that counts each time data is decoded for one picture;
(C) The video data is one picture by the data decoding means.
Timer that periodically counts a predetermined time for decoding for more than minutes
And (d) every time this timer measures a predetermined time.
Read the count value of the code counter, and
Comparison means for comparing the und value and the count value read this time
And (e) an image when the comparison result of this comparison means matches
Count value of the stop counter to stop decoding
Stop counter stepping means for stepping by one in a fixed direction;
(F) Stop counter by this stop counter
Shows a change of two or more predetermined values,
Playback state error that detects that an error has occurred in the playback state
The abnormality detecting system of the multimedia communication terminal device is provided with the detecting means.

That is, according to the first aspect of the present invention, a decode counter that changes the count value each time video data sent via a communication line is decoded by one picture, and a video decoding unit that converts the video data into one picture.
Timer that periodically counts a predetermined time for decoding for more than minutes
And the timer measures the predetermined time as described above.
Read the count value of the decode counter
Compare the count value read this time with the count value read this time,
To stop image decoding when the comparison result of
The stop counter counts up by one.
Or let the counter down. And this stop counter
That the change in the count value has reached a predetermined value of 2 or more
Detects that an error has occurred in the video signal playback status
In short, even if anomalies occur temporarily, they will continue to some extent
If not, abnormalities are not finally detected.

According to the second aspect of the present invention, (a) video data decoding means for decoding video data transmitted via a communication line, and (b) video data for one picture by the video data decoding means. A decoding counter which counts each time decoding is performed, and (c) data decoding means
Video data is decoded by one or more pictures
A timer that periodically measures the time of
Each time the predetermined time is counted, the decoding
Counter value, read the previously read count value
And a comparing means for comparing the count value read this time with (e)
When the comparison result of the comparing means matches, the decoding of the image is stopped.
The count value of the stop counter for stopping is fixed at 1
Stop counter stepping means for stepping in the direction;
Stop counter Predetermined stop counter by stepping means
When the change of two or more values
Reproduction state abnormality detection means for detecting occurrence of abnormality
If, (g) the reproduction state abnormality detecting means image data transmission stop instruction means for stopping the transmission of the video data to the transmission source that transmits video data via the communication line when detecting the abnormality of the reproduction state of the image Are provided in the abnormality detection system of the multimedia communication terminal device.

In other words, according to the second aspect of the present invention, a decode counter for changing the count value every time the video data transmitted via the communication line is decoded for one picture, and the video data is converted to one picture by the data decoding means.
Timer that periodically counts a predetermined time for decoding for more than minutes
And the timer measures the predetermined time as described above.
Read the count value of the decode counter
Compare the count value read this time with the count value read this time,
To stop image decoding when the comparison result of
The stop counter counts up by one.
Or let the counter down. And this stop counter
That the change in the count value has reached a predetermined value of 2 or more
Detects that an error has occurred in the video signal playback status
In short, even if anomalies occur temporarily, they will continue to some extent
If not, abnormalities are not finally detected.
Then, when an abnormality is detected , the transmission of the video data to the transmission source that transmits the video data is stopped.

According to the third aspect of the present invention, (a) video data decoding means for decoding video data sent via a communication line, and (b) video data for one picture by the video data decoding means. A decoding counter that counts this every time it is decoded, and (c) decoding this data
Means for decoding one picture or more of video data
A timer for periodically measuring a predetermined time;
Each time Ima measures the above specified time,
Counter value, read the previously read count value
And a comparing means for comparing the count value read this time with (e)
When the comparison result of the comparing means matches, the decoding of the image is stopped.
The count value of the stop counter for stopping is fixed at 1
A stop counter step means for stepping in the direction;
Stop counter Predetermined stop counter by stepping means
When the change of two or more values
Reproduction state abnormality detection means for detecting occurrence of abnormality
And (g) the playback state abnormality detecting means is the video playback state.
Video data is sent via the communication line when
Video to stop sending video data to the
Means for instructing stop of image data transmission, and (h) detecting a reproduction state abnormality
Displayed when the unit detects an abnormality in the video playback status
Abnormality display means, and (i) the abnormality occurrence display means
Indicates that the abnormal condition has been resolved
Resume video data transmission to the destination when separated
And an abnormality detection system for the multimedia communication terminal device.

That is, according to the third aspect of the present invention, a decode counter that changes the count value each time the picture data transmitted via the communication line is decoded by one picture, and the picture data is converted to one picture by the data decoding means.
Timer that periodically counts a predetermined time for decoding for more than minutes
And the timer measures the predetermined time as described above.
Read the count value of the decode counter
Compare the count value read this time with the count value read this time,
To stop image decoding when the comparison result of
The stop counter counts up by one.
Or let the counter down. And this stop counter
That the change in the count value has reached a predetermined value of 2 or more
Detects that an error has occurred in the video signal playback status
In short, even if anomalies occur temporarily, they will continue to some extent
If not, abnormalities are not finally detected.
Then, when an abnormality is detected , the transmission of the video data to the transmission source that transmits the video data is stopped, and the fact that the abnormality has occurred is displayed so that the user of the device on the receiving side can understand. . The display may be performed visually using a display such as a monitor, or may be performed by sound such as sounding a buzzer. When the abnormal state is resolved by removing the cause of the abnormality by the user or the like, the apparatus side can determine that the abnormality has been resolved by, for example, pressing the predetermined key by the user.
When the abnormal state is eliminated in this way, the video data transmission restart instructing means restarts the transmission of the video data to the transmission destination.

According to a fourth aspect of the present invention, in the abnormality detection system for a multimedia communication terminal device according to the first to third aspects , the comparing means compares the previously read count value with the currently read count value.
It is characterized by comparing the count values . Sand
That is, when two consecutive read count values of the decode counter become equal, the stop counter is counted.
And this value reaches a predetermined value of 2 or more.
Detects that an error has occurred in the video signal playback status
Anyway, the trouble that the user can tolerate
As for, abnormalities are not particularly detected.

According to a fifth aspect of the present invention, in the abnormality detection system for a multimedia communication terminal device according to the first to third aspects, the comparing means includes a count value read two times before and two times before.
Compare the count values read this time with these three cows.
When the count values are equal, the stop counter is counted,
When this value reaches two or more predetermined values, the video signal
In order to detect that an abnormality has occurred in the playback state,
For troubles that the user can tolerate,
Not to detect abnormalities.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments.

FIG. 1 shows an outline of the configuration of an abnormality detection system for a multimedia communication terminal device according to an embodiment of the present invention. This system has a configuration in which a headend device 21 and a multimedia communication terminal device 22 are connected by a transmission line 23 and a control signal line 24. Here, as shown in FIG. 9, the multimedia communication terminal device 22 is configured by a recording medium or a recording device for supplying and controlling the supply of multimedia data, for example. The transmission line 23 is a line for transmitting multimedia data such as video data, and the control signal line 24 is a line for transmitting and receiving a control signal for this transmission.

FIG. 2 shows a configuration of a multimedia communication terminal device according to the present embodiment. The multimedia communication terminal device 22 includes a video data input terminal 31 and a control signal input / output terminal 32. The video data input terminal 31 is connected to the transmission line 23 shown in FIG. 1, and receives the video data sent from the head end device 21 shown in FIG. The control signal input / output terminal 23 inputs and outputs a control signal to and from the head end device 21 via the control signal line 24 shown in FIG.

The multimedia data 33 input from the video data input terminal 31 is data for a plurality of channels. A desired channel is selected by a tuner 34 and input to an input signal system processing circuit 35. . The input signal system processing circuit 35 separates the input multimedia data into video data, audio data, and other data. The control signal input / output terminal 32 is connected to a communication circuit 36,
The control signal 37 is input / output via the control signal input / output terminal 32.

The input signal system processing circuit 35 and the communication circuit 36 are connected to a bus 39. Bus 3
9 includes a CPU (central processing unit) 41 for controlling the entire multimedia communication terminal device 22, a video data processing unit 42 for processing video data separated by the input signal system processing circuit 35, A display circuit 44 for displaying the processed video data on the monitor 43 and an audio data processing unit 45 for processing the audio data separated by the input signal system processing circuit 35 are connected. The video data processing unit 42 includes a video data buffer memory 47 for temporarily storing video data output from the input signal system processing circuit 35, and a video data decoding unit 48 for decoding video data output from the video data buffer memory 47. The decoded video data is input to the display circuit 44. The video data decoding section 48 includes a decode counter 49. The decode counter 49 counts up each time one picture, that is, one picture, is decoded, and the count value is supplied to this via the bus 39 when requested by the CPU 41. It is supposed to be.

On the other hand, the audio data output from the input signal system processing circuit 35 is
The data is input to the audio data buffer memory 51 and temporarily stored. Then, the audio data is input to the audio data decoding unit 52, decoded, amplified by an amplifier circuit 53 provided outside the audio data processing unit 45, and output from the speaker 54. A bus (not shown) storing a program for controlling the CPU 41 is provided on the bus 39.
Memory) and a RAM (random access memory), not shown, for temporarily storing data processed in the course of executing the program. Also, the CPU 41
Necessary instructions are input from an input device 56 constituted by a keyboard or the like.

FIG. 3 shows how the multimedia communication terminal having the above-described configuration performs interrupt control upon detection of an abnormality. The state of this interrupt processing will be described with reference to FIGS. The setting of the abnormality detection timing by this device is realized by periodically interrupting the CPU 41 using a software timer that counts a clock signal (not shown). The cycle of the interrupt by this software timer is
It is necessary to have a length sufficient to decode more than one picture, that is, one picture or more. In the present embodiment, for a reason to be described later, the head end device 21 retransmits the multimedia data 33 from the multimedia communication terminal device 22 after requesting the retransmission, and the head end device 21 retransmits the multimedia data 33 until the video is reproduced. Length time is required.

When the reproduction of the multimedia data starts, the software timer starts counting. As a result, when there is an interrupt input to the CPU 41 (start), the CPU 41 confirms this interrupt input (step S101). Then, it is determined whether or not the interruption is the first interruption after the start of reproduction (step S10).
2). The management of the number of interrupts is performed, for example, by clearing the numerical value related to the number of interrupts stored in the RAM at the start of playback, reading out this value each time an interrupt occurs, and counting up by "1" to store in the RAM. It can be realized by storing.

If it is the first interrupt (Y), C
The PU 41 reads the count value of the decode counter 49 (step S103), and stores the count value in the R
It is stored in a predetermined area of the AM (step S104), and this interrupt processing is ended (END). Then, the apparatus enters a standby state until the next interrupt processing. At this stage, there is no target for comparing the count value of the decode counter 49 yet.

If it is determined in step S102 that the interrupt is not the first interrupt (N), the decode counter 4
The value of 9 is read (step S105). This read value is read when an interrupt from the software timer occurs two times before and is overwritten on the previously stored count value in the RAM and stored (step S10).
6). Then, the value of the decode counter 49 read and overwritten when the current interrupt occurs and the value of the RA read and
It is determined whether or not the count value stored in M (this one has not been overwritten yet) is equal (step S107). Here, when it is determined that the count values are not equal (N), one or more pictures, that is, one or a plurality of pictures have been decoded, and the reproduction of the image has not been stopped. Therefore, since no abnormality is detected at this stage, the interrupt processing itself ends, and the abnormality detection is in a standby state until the next interrupt processing (end).

If it is determined in step S107 that the count values are the same (Y), the CPU 41 determines that an abnormality has occurred due to the stop of image decoding. Then, the video data decoding unit 48 is made to perform a process of blue-backing the video signal sent to the display circuit 44 (step S108). Then, mask processing is performed on the abnormal reproduced image output to the monitor 43. Thereafter, the CPU 41 notifies the head end device 21 as an upper device that an abnormality has occurred by an abnormality detection message (step S109). This abnormality detection message is output from the communication circuit 36 as a control signal 37 and transmitted to the head end device 21 via the control signal line 24 shown in FIG. Further, the CPU 41 performs processing for stopping the software timer (step S110),
This interrupt processing is terminated (END). The reason why the software timer is stopped is to prevent a situation in which abnormality is continuously detected in the subsequent interrupt processing.

FIG. 4 shows a flow of processing of the head-end device which has received the message of the abnormality detection from the multimedia communication terminal device. This processing will be described with reference to FIGS. Although not shown, the head end device 21 as a higher-level device includes a storage medium such as a magnetic disk storing a CPU and a program, and a working memory such as a RAM, and performs various controls by executing the program by the CPU. ing. When the head-end device 21 receives the error detection message (step S202; Y), the CPU in the device stops transmitting the multimedia data 33 to the multimedia communication terminal device 22 (step S202). Then, a response to the effect that transmission of the multimedia data 33 has been stopped is transmitted to the control signal line 24, and a series of processing for data transmission is completed (END).

FIG. 5 shows a flow of processing of the multimedia communication terminal device after transmitting an abnormality detection message to the head end device. This processing will be described with reference to FIGS. The CPU 41 in the multimedia communication terminal device 22 sends an abnormality detection message to the head-end device 21 and then proceeds to step S20.
3 (step S301). Then, when a response is received from the head end device 21 (Y), an instruction to display the abnormality detection confirmation information on the monitor 43 is given to the display circuit 44 (step S3).
02). This is for notifying the user who is the operator of the current state of the multimedia communication terminal device 22.

By receiving the abnormality detection confirmation information via the monitor 43, the user can grasp the current state of the multimedia communication system. Further, as the abnormality detection confirmation information, it is possible to display a cause that is likely to cause an abnormality and prompt the user to confirm the cause. For example, by prompting the user to confirm the connection state of the wiring, the user can confirm that the wiring of the transmission line 23 or the like is loose or disconnected. In the present embodiment, the processing does not proceed to the next step until the user performs these confirmations and performs a key input indicating that confirmation has been performed from the input device 56 (step S303; Y).

When the user performs a key input indicating that the confirmation has been made, the CPU 41 executes an initialization process of a portion for processing the input data of the multimedia communication terminal device 22 (step S304), and reproduces the video data decoding unit 48. The state is set (step S305). As a result, the image can be reproduced, and at this time, the CPU 41 starts the clocking operation of the software timer again (step S30).
6). Then, a request is made to the head end device 21 as a higher-level device to retransmit the multimedia data 33 (step S307).

FIG. 6 shows the processing sequence leading to abnormality detection and recovery between the multimedia communication terminal device and the head-end device according to the present embodiment. (Software).
The symbols for the processing steps already described with reference to FIGS. When the retransmission of the multimedia data 33 is requested in step S307 in FIG. 5, the head end device 21 responds to the request (step S401 in FIG. 6), and sends the multimedia data 33 to the multimedia communication terminal device 22 again. 33 is transmitted (step S402).

As described above, in the abnormality detection system for the multimedia communication terminal device of the present embodiment, the abnormality of the multimedia communication terminal device 22 is detected by detecting the image stop on the side of the multimedia communication terminal device 22 using the software counter. In addition, the reproduction of the multimedia data 33 is started again after the recovery processing is performed. In this embodiment, the description has been made on the assumption that reproduction is performed at a normal speed. However, the same processing sequence can be applied to an abnormality that occurs in a state where special reproduction such as slow reproduction is performed.

Modification

FIG. 7 shows the first half of a process as a modification of the interrupt process described in the embodiment. The state of this interrupt processing will be described with reference to FIGS. The setting of the abnormality detection timing by this device
CPU 4 using the software timer described in the embodiment
This is realized by periodically interrupting 1.

When the reproduction of the multimedia data starts, the software timer starts counting. As a result, when there is an interrupt input to the CPU 41 (start), the CPU 41 confirms this interrupt input (step S501). Then, it is determined whether or not the interruption is the first interruption after the start of reproduction (step S50).
2). The management of the number of interrupts is performed, for example, by clearing the numerical value related to the number of interrupts stored in the RAM at the start of playback, reading out this value each time an interrupt occurs, and counting up by "1" to store in the RAM. It can be realized by storing.

If it is the first interrupt (Y), C
The PU 41 reads the count value of the decode counter 49 (step S503), and stores the count value in the R
It is stored in a predetermined area of the AM (step S504), and this interrupt processing is terminated (END). Then, the apparatus enters a standby state until the next interrupt processing. At this stage, there is no target for comparing the count value of the decode counter 49 yet.

If it is determined in step S102 that the interrupt is not the first interrupt (N), it is determined whether the interrupt input is the second interrupt (step S505).
If it is the second interrupt (Y), the value of the decode counter 49 is read (step S505), and this count value is stored in another predetermined area of the RAM (step S507). Then, similarly, the apparatus enters a standby state until the next interrupt processing.

FIG. 8 shows the flow of subsequent processing when it is determined in step S505 in FIG. 7 that the interrupt is the second or later interrupt. If it is determined that the interrupt is the second or later interrupt (step S505; N),
The count value of the decode counter 49 is read (step S508), and this is read when an interrupt from the software timer occurs two times before and is overwritten and stored on the already stored count value on the RAM (step S509). ). Then, the value of the decode counter 49 read and overwritten at the time of the occurrence of the current interrupt is compared with the count value read and stored in the RAM at the time of the occurrence of the interrupt from the previous software timer. And compares the count value read and stored in the RAM with the count value read and stored in the RAM two times before the occurrence of the interrupt from the software timer (step S51).
0). Then, it is determined whether or not all three values of the decode counter 49 at the time of the last and last two interrupts are equal (step S511).

If any one of these values is different (N), a software counter (hereinafter referred to as an image decoding stop counter) stored in a count value storage area newly provided in the RAM described above. Is set to "0" (step S512). In this state, since the number of times of capturing the video changes with time, there is a high possibility that the decoding of the image has not completely stopped. Therefore, the content of the image decoding stop counter is cleared, the interrupt processing is terminated, and a standby state for interruption by the software timer is set (end).

On the other hand, when the three count values counted by the decode counter 49 are all equal (step S511; Y), the count value of the image decoding stop counter is incremented by "1" (step S511).
513). Then, it is checked whether or not this count value is a predetermined integer of 2 or more (step S5).
14). In this embodiment, this integer is set to “10”. If it has not reached “10” (N), it is quicker to determine that image decoding has been completely stopped due to the occurrence of an abnormality. Therefore, in this case, the interrupt processing ends, and a standby state for interruption by the software timer is set (end).

On the other hand, when the count value of the image decoding stop counter becomes "10" (step S514;
Y), the CPU 41 determines that the apparatus is abnormal due to the stop of image decoding. Then, the video data decoding unit 48 is caused to perform a process of blue-backing the video signal sent to the display circuit 44 (step S515).
Then, mask processing is performed on the abnormal reproduced image output to the monitor 43. Thereafter, the CPU 41 notifies the head end device 21 as an upper device of the occurrence of the abnormality with an abnormality detection message (step S).
516). This abnormality detection message is output from the communication circuit 36 as a control signal 37 and transmitted to the head end device 21 via the control signal line 24 shown in FIG. Further, the CPU 41 performs processing for stopping the software timer (step S517), and terminates this interrupt processing (end).

The reason why the software timer is stopped is to prevent the count value from increasing forever. In step S514, since the abnormality is detected only when the count value of the image decoding stop counter becomes "10", the abnormality is not continuously detected in the subsequent interrupt processing. However, if it is determined in step S514 whether or not the count value of the image decoding stop counter is “10” or more, the processing in step S517 is abnormal in the subsequent interrupt processing as in the previous embodiment. Has the meaning of preventing the detection of from being performed continuously.

As described above, there is a slight difference in the interrupt processing between the embodiment and the modification. The interrupt processing described in the embodiment is particularly preferable when the interrupt timing is relatively long.
For example, assuming that 30 images are decoded per second when the interrupt occurrence timing is 10 seconds, the multimedia communication terminal device 22 needs to decode 300 images during the 10 seconds. If there is no change in the count value of the decode counter 49 during these 10 seconds, it can be clearly determined that there is an abnormality.

On the other hand, when the interrupt timing is relatively short, the interrupt process of the modified example is often suitable. For example, it is assumed that the interrupt timing is 0.5 seconds and a momentary line disconnection occurs in the transmission line 23. Thereafter, assuming that the transmission line 23 normally transmits the multimedia data 33, the user recognizes an instantaneous stop of the image, but after that, normal reproduction is performed. Performing the display gives an unnatural impression to the user. In order to avoid such inconvenience, it is not sufficient to determine the abnormality detection by comparing only the two front and rear screens in addition to the short detection timing. Therefore, in the modified example, comparison for three screens is performed, and for a certain period of time (in the embodiment, the count value of the image decoding stop counter is set to “1”.
Until it becomes 0 ”or more), the abnormality detection determination is continued. With this, even in the multimedia communication terminal device 22 whose interrupt timing is relatively short,
Abnormality can be detected with sufficient accuracy.

In the interrupt processing of this modified example, when the decode counter 49 operates on the basis of the vertical synchronizing signal (V-SYNC) generated at the time of reproducing a video, the following contents are dealt with. can do. That is,
When the decoding of the image is normally performed, the counting is not performed. When the counting is performed at the generation timing of the vertical synchronization signal when the image is stopped, the determination criterion in step S511 is set to “3 times”. Are all the values different? "

[0049]

As described in detail above, according to the first aspect of the present invention , a stop counter is provided in addition to a decode counter.
And the stop counter detects a change of two or more predetermined values.
Indicates that an error has occurred in the playback status of the video signal.
Since we decided to detect it,
Make sure not to detect any abnormalities
Advantage of not complicating user processing
There is.

[0050] Also, according to claim according to the invention of claim 2, wherein
In addition to obtaining the same effects as the invention described in Item 1,
Is detected, the transmission of the video data is stopped for the transmission source of the video data. Therefore, the data transmission side of multimedia data etc. must also detect that an abnormality has occurred on the reception side. Can work together with the receiving user to restore the system,
The abnormal situation can be recovered more quickly.

According to the third aspect of the present invention, the first aspect is provided.
In addition to obtaining the same effects as the described invention,
When the detection is detected , the transmission of the video data to the transmission source of the video data is stopped, and the fact that an abnormality has occurred is displayed on the receiving device so that the user can recognize it. It is possible to make the user take an appropriate measure even for such an abnormality. Also, when the abnormal situation is resolved, it can be detected, and at this time, the video data transmission restart instruction for restarting the transmission of the video data to the transmission destination is performed. Further, the time until the display of the image is restarted can be reduced.

According to the invention described in claim 4 or 5, the comparing means compares the previously read count value with the current read value.
Two counts, or the cow read twice before
Count value, last read count value, and current read count value
Since the three values of the default value are to be compared,
In addition to the counter count, the user side
It is possible to determine what is better by simple data processing
Simplifies the equipment configuration and ensures reliable detection
The result can be obtained.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of an abnormality detection system of a multimedia communication terminal device according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a multimedia communication terminal device according to the present embodiment.

FIG. 3 is a flowchart showing how the multimedia communication terminal device of the present embodiment performs interrupt control when an abnormality is detected.

FIG. 4 is a flowchart showing a processing flow of a head-end device which has received a message of abnormality detection from a multimedia communication terminal device.

FIG. 5 is a flowchart illustrating a process flow of the multimedia communication terminal device after transmitting an abnormality detection message to the head end device.

FIG. 6 is an explanatory diagram showing a processing sequence leading to abnormality detection and recovery, focusing on a relationship between hardware on the multimedia communication terminal device side and a processing function of a CPU;

FIG. 7 is a flowchart showing a first half of an interrupt process according to a modified example of the present invention.

FIG. 8 is a flowchart showing a latter half of an interrupt process according to a modified example of the present invention.

FIG. 9 is a system configuration diagram showing an outline of a conventionally proposed CATV system.

[Explanation of symbols]

 Reference Signs List 21 head end device 22 multimedia communication terminal device 23 control signal input / output terminal 33 multimedia data 41 CPU 42 video data processing unit 43 monitor 44 display circuit 48 video data decoding unit 49 decode counter 56 input device

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N ⁷ /16-7/173 H04L 29/14 H04N ⁷ /24-7/68

Claims (5)

(57) [Claims] 1. A video data decoding means for decoding video data sent via a communication line, a decode counter for counting the video data each time one picture is decoded by the video data decoding means, and , Video data for one picture by the data decoding means.
Timer for periodically counting the predetermined time for decoding
When the deco this timer each time it counts a predetermined time
Read the count value of the
Means for comparing the count value with the count value read this time, and stops decoding the image when the comparison result of the comparison means matches.
The count value of the stop counter for stopping is fixed at 1
A stop counter incremented means for stepping direction, said stop counter by the stop counter increment means
When a change of two or more predetermined values is shown, the video signal
Playback state error detection that detects that an error has occurred in the raw state
An abnormality detection system for a multimedia communication terminal device, comprising: an output unit . 2. A video data decoding means for decoding video data transmitted via a communication line, a decode counter for counting the video data each time one picture is decoded by the video data decoding means, and , Video data for one picture by the data decoding means.
Timer for periodically counting the predetermined time for decoding
When the deco this timer each time it counts a predetermined time
Read the count value of the
Means for comparing the count value with the count value read this time, and stops decoding the image when the comparison result of the comparison means matches.
The count value of the stop counter for stopping is fixed at 1
A stop counter incremented means for stepping direction, said stop counter by the stop counter increment means
When a change of two or more predetermined values is shown, the video signal
Playback state error detection that detects that an error has occurred in the raw state
Means out, the reproduction state abnormality detecting means abnormalities in reproduction state of the image search
Abnormality detection system of the multimedia communication terminal apparatus characterized by comprising the image data transmission stop instruction means for stopping the transmission of the video data to the transmission source that transmits video data via the communication line when the output . 3. A video data decoding means for decoding video data sent via a communication line, a decode counter for counting the video data every time one picture is decoded by the video data decoding means, and , Video data for one picture by the data decoding means.
Timer for periodically counting the predetermined time for decoding
When the deco this timer each time it counts a predetermined time
Read the count value of the
Means for comparing the count value with the count value read this time, and stops decoding the image when the comparison result of the comparison means matches.
The count value of the stop counter for stopping is fixed at 1
A stop counter incremented means for stepping direction, said stop counter by the stop counter increment means
When a change of two or more predetermined values is shown, the video signal
Playback state error detection that detects that an error has occurred in the raw state
Means out, the reproduction state abnormality detecting means abnormalities in reproduction state of the image search
Detection and image data transmission stop instruction means for stopping the transmission of the video data to the transmission source that transmits video data via the communication line when out, the reproduction state abnormality detecting means abnormalities in reproduction state of the image
When leaving the error occurrence display means for displaying this video to restart the delivery of the video data to the destination when the abnormal state after the abnormality occurrence display means displaying the abnormality is judged that it has eliminated An abnormality detection system for a multimedia communication terminal device, comprising: data transmission restart instruction means. 4. The comparison means according to claim 1, wherein
4. The abnormality detection system for a multimedia communication terminal device according to claim 1 , wherein the count values read this time are compared . 5. The method according to claim 1, wherein the comparing means reads the count value read two times before.
Of the previously read count value and the current read count value
Comparing the three count values, the stop counter increment means
Stops when all three count values match.
4. The abnormality detection system for a multimedia communication terminal device according to claim 1, wherein the count value of the stop counter is changed by one .