JP2007329773A - Packet loss characteristic analysis apparatus, method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packet loss characteristic analysis apparatus, method, and program capable of accurately discriminating video image deterioration due to a burst packet loss. <P>SOLUTION: A video deterioration discrimination section 12 discriminates invalid packets which a receiver side application terminal 2B cannot normally receive among media packets on the basis of transmission quality information and received quality information and discriminates the presence/absence of the video deterioration from the invalid packets by each invalid packet detection time within a prescribed video deterioration discrimination period on the basis of an assumed burst discrimination condition 13 for denoting a production state of the invalid packets within an optional invalid packet detection time, and a burst discrimination condition determining section 15 calculates an accuracy rate of a result of the video deterioration discrimination obtained from the video deterioration discrimination section by each of different burst discrimination conditions on the basis of a result of a video deterioration evaluation from a quality evaluation acquisition section 14 and determines an assumed burst discrimination condition indicating the highest accuracy rate as a burst discrimination condition 17. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a communication quality estimation technique, and more particularly to a technique for analyzing a packet loss characteristic that affects a user experience quality of a real-time application.

  In recent years, with the rapid development of packet communication technology, packet networks are being used in real-time applications that communicate media (contents) such as audio and video one-to-one or between multiple points. In the in-service quality management of the packet network, quality management for such an application is also required. Especially in real-time applications, quality management using user experience quality such as subjective or objective quality at the user level that actually uses the application is regarded as important, and technology that estimates user experience quality from network quality Have also been proposed (see, for example, Non-Patent Document 1).

Conventionally, the inventors have, as a technique for estimating the subjective quality of real-time applications, for example, a quality monitoring technique that takes into account the environment in which bursty packet loss such as continuous packet loss occurs on the transmission path and terminal (For example, refer to Patent Document 1).
In this technique, a reduction amount of a user experience quality evaluation value for an application due to burst loss in which packets are lost in a burst manner is estimated, and a network quality management target value is calculated based on the reduction amount.

JP-A-2005-244609 A. Clark, "Modeling the effects of burst packet loss and recency on subjective voice quality", IP Telephony Workshop 2001, Apr. 2001 http://www.digitalfountain.com/technology/index.cfm

  In recent years, in video distribution services such as streaming, many services using an FEC function (Forward Error Correction / see Non-Patent Document 2 etc.) are provided as a technique for enhancing the packet loss system. When this FEC function is used, a packet including information for performing repair when a packet loss occurs is transmitted in parallel with the application packet. Therefore, when one packet is randomly lost, this technique is used. Is more likely to be repaired.

FIG. 15 is an explanatory diagram showing the effect of the FEC function, in which the horizontal axis represents the packet loss rate and the vertical axis represents the number of times of video degradation detection. Characteristic 61 shows a case of random loss in which the number of lost packets is 1 and a plurality of packets are not continuously lost. When the packet loss rate is low, the loss is repaired to some extent by the FEC function, and video degradation is not much. It turns out that it is not detected. On the other hand, the characteristic 62 shows a case of burst loss in which the number of lost packets varies from 1 to 6, and even when the packet loss is low, the loss may not be repaired by the FEC function, and video degradation is detected to some extent. I understand that.
As described above, in the video communication service to which the FEC function is applied, there is a high possibility that the video quality is deteriorated only when packet loss occurs in a burst manner.

On the other hand, even if an application packet is lost, it may not be perceived as video degradation. For example, when various types of frames obtained by encoding video are transferred as application packets, some application packets transfer information that cannot be perceived by humans.
Therefore, the loss resistance against such random packet loss is high, and the video communication with the quality degradation characteristic that the deterioration of the video quality is first seen due to the bursty packet loss is high considering the bursty packet loss. When estimating the user experience quality with accuracy, it is necessary to distinguish video degradation that has occurred without obtaining the effect of the FEC function from other video degradation such as video degradation that humans cannot perceive.

  However, the above-described prior art does not take into account video communication having a quality deterioration characteristic such that the loss resistance against such random packet loss is high and the video quality is first deteriorated due to bursty packet loss. Therefore, there has been a problem that video degradation due to bursty packet loss cannot be accurately determined.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a packet loss characteristic analysis apparatus, method, and program capable of accurately determining video degradation due to bursty packet loss. .

  In order to achieve such an object, the packet loss characteristic analysis apparatus according to the present invention provides a loss characteristic of media packets used for video communication between a transmission side and a reception side application terminal connected via a packet network. A packet loss characteristic analysis apparatus that outputs a burst determination condition for determining burst loss of a media packet that causes degradation of the video quality by analyzing the medium transmitted from the transmission-side application terminal Quality information acquisition unit for acquiring transmission quality information indicating the transmission status of the packet for use and reception quality information indicating the reception status of the media packet received by the reception-side application terminal; A quality evaluation acquisition unit that acquires evaluation results regarding degradation, transmission quality information, and reception Based on the quality information, determine the invalid packet that could not be normally received by the receiving application terminal among the media packets, and based on the assumed burst determination condition indicating the occurrence status of the invalid packet within any invalid packet detection time, Based on the video degradation assessment result from the video degradation assessment result from the quality assessment acquisition unit and the video degradation assessment unit that judges the presence or absence of video degradation from the invalid packet for each invalid packet detection time within the predetermined video degradation judgment period, A burst determination condition determination unit that calculates a correct answer rate of the video deterioration determination result obtained from the video deterioration determination unit and determines an assumed burst determination condition indicating the highest correct answer rate as a burst determination condition;

  At this time, as an assumed burst determination condition, a set of an assumed burst time for defining the period length of the invalid packet detection time and an assumed burst determination packet number for determining the number of invalid packets detected within the invalid packet detection time. In the video degradation determination unit, the invalid packet detection time having the period length of the assumed burst time is continuously provided within the video degradation determination period, and the number of invalid packets within the arbitrary invalid packet detection time and the assumed burst determination packet Based on the comparison result with the number of images, the presence / absence of video degradation in the invalid packet detection time is determined, and the burst determination condition determination unit determines the video for each assumed burst condition including a set of various assumed burst times and the number of assumed burst determination packets. Calculate the correct answer rate of the video deterioration judgment result obtained from the deterioration judgment unit, and the assumed burst time indicating the highest correct answer rate and The constant burst determination packet number set may be output as a burst determination condition.

  Alternatively, as an assumed burst determination condition, a set of an assumed burst time for defining the length of the invalid packet detection time and an assumed burst determination packet number for determining the number of invalid packets detected within the invalid packet detection time In the video degradation determination unit, an invalid packet detection time having a period length of an assumed burst time from the time of occurrence of an arbitrary invalid packet is provided, and the number of invalid packets within the invalid packet detection time and the number of assumed burst determination packets Based on the comparison result, the presence / absence of video degradation in the invalid packet detection time is determined, and the burst determination condition determination unit determines the video degradation determination unit for each hypothetical burst condition including a set of various assumed burst times and the number of assumed burst determination packets. Calculate the correct answer rate of the video deterioration judgment result obtained from the above and calculate the assumed burst time indicating the highest correct answer rate. Fine assumed burst determined number of packets set may be output as a burst determination condition.

  Alternatively, as an assumed burst determination condition, an assumed packet density determination amount that defines the number of invalid packet intervals used for determining the end of invalid packet detection time, and an assumed burst determination for determining the number of invalid packets detected within the invalid packet detection time Using the pair with the number of packets, the video degradation determination unit determines the invalid packet detection time from the time when any invalid packet occurs until the number of invalid packet intervals from the next invalid packet to the estimated packet density judgment amount or more. The presence / absence of video degradation at the invalid packet detection time is determined based on the comparison result between the number of invalid packets within the invalid packet detection time and the number of assumed burst determination packets. Video inferior for each assumed burst condition consisting of a set of decision amount and number of assumed burst decision packets. Calculating the accuracy rate of the video degradation determination result obtained from the determination unit, the highest assuming shows the accuracy rate packet density determination amount and assumptions bursts determining the number of packets set may be output as a burst determination condition.

  In addition, whether or not video degradation has been detected in each of the degradation time point determined as having video degradation by the video degradation judgment result and the degradation time point evaluated as having video degradation in the video degradation evaluation result by the burst judgment condition determination unit And the correct answer rate may be calculated based on the total value of the correct answer scores corresponding to the comparison results at the time of deterioration.

  Also, a determination target packet selection that determines a frame type of the video corresponding to the media packet based on the reception quality information, and selects a determination target packet that is a target of video degradation out of the media packet based on the frame type A video degradation determination unit may determine whether video degradation has occurred from an invalid packet selected as a determination target packet among invalid packets.

  In addition, the video degradation determination unit indicates the arrival interval of media packets whose reception quality information is not confirmed among the media packets whose transmission quality is confirmed by the transmission quality information, and each media packet of the reception quality information. A media packet whose delay fluctuation time exceeds the allowable packet delay time of the application may be determined as an invalid packet.

  Further, the video degradation determination unit may determine that a media packet in which the transmission order and the reception order of the media packet confirmed to be received by the reception quality information are inconsistent is an invalid packet.

  The packet loss characteristic analysis method according to the present invention analyzes the loss characteristics of media packets used for video communication between a transmission side and a reception side application terminal connected via a packet network, thereby obtaining the video quality. A packet loss characteristic analysis method used in a packet loss characteristic analysis apparatus that outputs a burst determination condition for determining burst loss of a media packet, which is a cause of degradation of a media packet. Quality information acquisition step for acquiring transmission quality information indicating the transmission status of media packets transmitted from the terminal and reception quality information indicating the reception status of media packets received by the receiving application terminal, and quality evaluation acquisition Part of the video that is played back on the receiving application terminal. A quality evaluation acquisition step for acquiring an evaluation result, and a video degradation determination unit to determine an invalid packet that could not be normally received by the receiving-side application terminal among media packets based on transmission quality information and reception quality information, Video degradation determination that determines the presence / absence of video degradation from invalid packets for each invalid packet detection time within a predetermined video degradation determination period based on an assumed burst judgment condition indicating the occurrence status of invalid packets within an arbitrary invalid packet detection time Based on the video degradation evaluation result from the quality evaluation acquisition unit, the correct rate of the video degradation determination result obtained from the video degradation determination unit for each different burst determination condition is calculated by the step and the burst determination condition determination unit, and the highest Burst judgment condition that determines hypothetical burst judgment condition indicating correct answer rate as burst judgment condition And a constant step.

  Further, the program according to the present invention causes degradation of the video quality by analyzing the loss characteristics of media packets used for communication between the transmission-side and reception-side application terminals connected via the packet network. Shows the transmission status of media packets transmitted from the application terminal on the transmission side by the quality information acquisition unit to the computer of the packet loss characteristic analysis device that calculates burst judgment conditions for judging burst loss of media packets. Quality information acquisition step for acquiring the transmission quality information and the reception quality information indicating the reception status of the media packet received by the receiving application terminal, and degradation of the video reproduced by the receiving application terminal by the quality evaluation acquisition unit A quality evaluation acquisition step for acquiring an evaluation result for Based on the transmission quality information and reception quality information, the image degradation determination unit determines invalid packets that could not be normally received by the receiving application terminal from among the media packets, and generation of invalid packets within any invalid packet detection time Based on an assumed burst determination condition indicating the situation, a video deterioration determination step for determining presence / absence of video deterioration from an invalid packet every invalid packet detection time within a predetermined video deterioration determination period, and a burst evaluation condition determination unit for quality evaluation Based on the video degradation evaluation result from the acquisition unit, the correct rate of the video degradation judgment result obtained from the video degradation judgment unit is calculated for each different burst judgment condition, and the assumed burst judgment condition indicating the highest accuracy rate is determined as the burst judgment condition. And a burst determination condition determination step determined as follows.

  According to the present invention, the video degradation determination unit determines invalid packets that could not be normally received by the receiving-side application terminal based on the transmission quality information and the reception quality information, and the invalid packet within an arbitrary invalid packet detection time is determined. Based on the assumed burst determination condition indicating the occurrence status, presence / absence of video deterioration is determined from the invalid packet for each invalid packet detection time within a predetermined video deterioration determination period, and the burst determination condition determination unit Based on the video degradation evaluation result, the correct rate of the video degradation determination result obtained from the video degradation determination unit is calculated for each different burst determination condition, and the assumed burst determination condition indicating the highest correct rate is output as the burst determination condition. .

As a result, it is possible to obtain a burst determination condition for accurately distinguishing video degradation that has occurred without obtaining the effect of the FEC function from other video degradation such as video degradation that cannot be perceived by humans.
Therefore, by determining the generation status of invalid packets within an arbitrary invalid packet detection time based on the burst determination condition obtained in the present invention, it is possible to determine whether or not video degradation has occurred without obtaining the effect of the FEC function. The corresponding video communication state can be accurately determined.

  For this reason, it is possible to use an appropriate quality estimation method according to the video communication state, such as selecting a different quality estimation model based on the video communication state, and the loss tolerance against random packet loss is high, and bursty It is possible to accurately estimate the user experience quality even for video communication having a quality degradation characteristic in which the video quality is first degraded due to packet loss.

Next, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
First, a packet loss characteristic analyzing apparatus according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of a packet loss characteristic analyzing apparatus according to a first embodiment of the present invention.

  The packet loss characteristic analysis device 1 includes an information processing device having a communication function, and a communication quality evaluation device 3 provided in an application terminal 2 (2A, 2B) or a reception-side application terminal 2B connected via a packet network 5. To determine the burst loss of media packets that cause degradation of the video quality by analyzing the loss characteristics of media packets used for video communication between these application terminals 2. Outputs burst judgment conditions.

  The packet loss characteristic analysis apparatus 1 includes a quality information acquisition unit 11, a video degradation determination unit 12, a quality evaluation acquisition unit 14, and a burst determination condition determination unit 15 as main functional units.

  In this embodiment, the video degradation determination unit 12 determines an invalid packet that could not be normally received by the reception-side application terminal 2B among media packets based on the transmission quality information and the reception quality information. Based on the assumed burst determination condition 13 indicating the occurrence state of invalid packets within the detection time, it is determined whether or not video degradation has occurred from invalid packets at each invalid packet detection time within a predetermined video degradation determination period, and a burst determination condition determination unit 15, based on the video degradation evaluation result from the quality evaluation acquisition unit 14, the correct burst rate of the video degradation determination result obtained from the video degradation determination unit is calculated for each different burst determination condition, and the assumed burst indicating the highest correct rate The determination condition is determined as the burst determination condition 17.

  Each functional unit of the packet loss characteristic analyzing apparatus 1 includes a dedicated circuit unit, an arithmetic processing unit, and a storage unit. In particular, the arithmetic processing unit (computer) includes a microprocessor such as a CPU and its peripheral circuits, and reads and executes a program stored in a memory or a storage unit in the peripheral circuit, whereby the hardware and program To realize each functional unit. The storage unit includes a storage device such as a memory and a hard disk, and stores various processing information used for processing in each functional unit.

  The quality information acquisition unit 11 has a function of acquiring transmission quality information indicating the transmission status of media packets transmitted from the transmission-side application terminal 2A from the transmission-side application terminal 2A, and a media packet received by the reception-side application terminal 2B. A reception quality information indicating the reception status of the application terminal 2B. It collects (captures) media packets of the video from a packet transfer device such as a hub (HUB) or terminal adapter (TAP) provided between the application terminal 2 (2A, 2B) and the packet network 5. Transmission quality information and reception quality information may be acquired from these media packets.

  The main quality information included in the acquired transmission quality information includes a sequence number indicating a transmission order, a video frame type, a video frame number, the number of transmission packets, and the number of transmission frames regarding each transmission media packet. The main quality information included in the reception quality information includes a sequence number indicating the transmission order and a delay fluctuation time indicating the arrival time difference from the immediately preceding media packet for each received media packet.

  The video degradation determination unit 12 has a function of determining an invalid packet that has not been normally received from media packets transmitted based on the transmission quality information and the reception quality information acquired by the quality information acquisition unit 11, and an arbitrary invalidity. A function of determining the presence / absence of video degradation from invalid packets for each invalid packet detection time within a predetermined video degradation judgment period based on an assumed burst judgment condition 13 indicating the occurrence state of invalid packets within the packet detection time. ing. The assumed burst determination condition 13 may be set in advance in a storage unit (not shown), or may be input at the start of the packet loss characteristic analysis process.

  An invalid packet is a packet that cannot be normally received by the receiving real-time application and cannot be reproduced as media among media packets that contain media (content) data sent from the sending real-time application. is there. Specifically, a packet lost on a transmission line connecting the transmission-side application terminal 2A and the reception-side application terminal 2B via the packet network 5, a delay arrival that the arrival interval could not be adjusted by the fluctuation absorbing buffer of the reception-side application Packets, and packets in which the arrival order of media packets is reversed in a real-time application in which the arrival order of media packets is specified are targeted.

  The quality evaluation acquisition unit 14 has a function of acquiring a video deterioration evaluation result related to a video received and reproduced by the reception-side application terminal 2B from the communication quality evaluation device 3 provided in the reception-side application terminal 2B. As the video degradation evaluation result, for example, information regarding the video degradation perceived by humans from the video reproduced by the reception-side application terminal 2B may be used.

  The burst determination condition determination unit 15 calculates the correct rate of the video degradation determination result obtained from the video degradation determination unit 12 for each of different burst determination conditions based on the video degradation evaluation result from the quality evaluation acquisition unit 14 and stores it. And a function for storing the assumed burst determination condition indicating the highest accuracy rate among the determination result information 16 as a desired burst determination condition 17.

[Video degradation judgment processing]
Next, with reference to FIG. 2 and FIG. 3, the video degradation determination process in the packet loss characteristic analysis apparatus according to the first exemplary embodiment of the present invention will be described in detail. FIG. 2 is a flowchart showing video degradation determination processing in the packet loss characteristic analysis apparatus according to the first exemplary embodiment of the present invention. FIG. 3 is an explanatory diagram illustrating a video degradation determination operation in the packet loss characteristic analysis apparatus according to the first embodiment of the present invention.

As the video degradation determination process executed by the video degradation determination unit 12 of the packet loss characteristic analysis apparatus 1, several specific processing methods can be considered as will be described later.
In the present embodiment, the assumed burst determination condition 13 includes an assumed burst time for defining the period length of the invalid packet detection time, and an assumed burst determination packet for determining the number of invalid packets detected within the invalid packet detection time. The invalid packet detection time having a period length of the assumed burst time is continuously provided in the video degradation determination period, and the number of invalid packets and the number of assumed burst determination packets in any invalid packet detection time. A case where the presence / absence of video degradation in the invalid packet detection time is determined based on the comparison result will be described as an example.

  At this time, the video deterioration determination process is executed every video deterioration determination period of, for example, about 3 minutes among the videos transmitted by the media packet exchanged between the transmission / reception application terminals 2A and 2B. Also, a plurality of invalid packet detection times are provided within the video degradation determination period, and the presence / absence of video degradation is determined from the invalid packets for each invalid packet detection time based on the assumed burst determination condition 13.

Here, an example in which the video encoded in each frame at the transmission side application terminal 2A is stored in each media packet and transmitted, and is received by the reception side application terminal 2B via the packet network 5 and reproduced. Will be described.
The transmission quality information and the reception quality information are acquired from the application terminals 2A and 2B by the quality information acquisition unit 11 using control packets such as RTCP XR (RTP Control Protocol) before starting the video deterioration determination process. It shall be.

The video deterioration determination unit 12 of the packet loss characteristic analysis device 1 can normally receive the media packet transmitted based on the transmission quality information and the reception quality information acquired by the quality information acquisition unit 11 at the reception-side application terminal 2B. Judge invalid packets that did not exist.
Thereafter, the video degradation determination unit 12 executes the video degradation determination process of FIG. 2 to perform predetermined video based on a hypothetical burst determination condition 13 indicating the generation status of invalid packets within an arbitrary invalid packet detection time. The presence / absence of video degradation is determined from invalid packets at each invalid packet detection time within the degradation determination period.

  In the video degradation determination process of FIG. 2, the video degradation determination unit 12 first acquires an arbitrary assumed burst determination condition 13 from the storage unit (step 100). The assumed burst determination condition 13 is information that is a candidate for the desired burst determination condition 17, and a plurality of assumed burst determination conditions 13 having different values are stored in the storage unit in advance.

  The hypothetical burst determination condition 13 includes information that defines the generation status of invalid packets within the invalid packet detection time. In the present embodiment, as shown in FIG. 3, the video is based on the assumed burst time having a value of about 10 ms, for example, which defines the length of the invalid packet detection time, and the number of invalid packets detected within the invalid packet detection time. For example, a combination with the assumed burst determination packet number having a value of about the number of packets = 3 is used as the assumed burst determination condition 13.

Next, the video deterioration determination unit 12 initializes a count value of the number of invalid packets detected within the invalid packet detection time (step 101), and starts measuring a new invalid packet detection time (step 102).
Subsequently, based on the reception quality information and the invalid packet determination result, the video degradation determination unit 12 can normally receive the packet successfully received by the reception-side application terminal 2B within the invalid packet detection time among the transmitted media packets. The processing packets including the invalid packets that have not existed are selected one by one in time order (step 103). Note that once selected processing packets are not selected again.

  Only when the selected processing packet is an invalid packet (step 103: YES), the number of invalid packets is counted (step 104), and steps 103 and 104 are performed until the invalid packet detection time has elapsed for the assumed burst time. Repeatedly execute (step 105: NO).

On the other hand, when the invalid packet detection time has elapsed for the assumed burst time in step 105 (step 105: YES), the number of invalid packets is compared with the assumed burst determination packet number (step 106).
Here, only when the number of invalid packets is equal to or greater than the number of assumed burst determination packets (step 106: YES), it is determined that there is video degradation in the invalid packet detection time, and the number of video degradation detections counted so far is 1 In addition, the start time of the invalid packet detection period is stored in the storage unit as the video degradation occurrence time (step 107).

  After this, if the video deterioration determination period has not ended (step 108: NO), the process returns to step 101 to repeatedly execute the video result determination process for the next invalid packet detection time, and according to the end of the video deterioration determination period. (Step 108: YES), a series of video deterioration determination processing is terminated.

  In the example of FIG. 3, although two invalid packets are detected within the first invalid packet detection time, the number of invalid packets “2” is smaller than the assumed burst determination packet number “3”, so it is determined that there is no video degradation. Is done. On the other hand, four invalid packets are detected within the next invalid packet detection time, and the number of invalid packets “4” is equal to or greater than the number of assumed burst determination packets “3”.

  Thus, in the present embodiment, as the assumed burst determination condition 13, the assumed burst time for defining the period length of the invalid packet detection time and the number of invalid packets detected within the invalid packet detection time are determined. Using the set with the number of assumed burst determination packets, the video degradation determination unit 12 continuously provides invalid packet detection times having a period length of the assumed burst time within the video degradation determination period, and within any arbitrary invalid packet detection time Based on the comparison result between the number of invalid packets and the assumed burst determination packet number, the presence / absence of video degradation at the invalid packet detection time is determined. Can be determined. Further, an average video deterioration determination result can be obtained for the video deterioration determination period.

[Operation of First Embodiment]
Next, the operation of the packet loss characteristic analysis apparatus according to the first exemplary embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a flowchart showing packet loss characteristic analysis processing in the packet loss characteristic analysis apparatus according to the first exemplary embodiment of the present invention. FIG. 5 is an explanatory diagram illustrating a correct rate calculation operation of the packet loss characteristic analysis apparatus according to the first embodiment of the present invention. FIG. 6 is an explanatory diagram showing a burst condition determining operation of the packet loss characteristic analyzing apparatus according to the first embodiment of the present invention.

  Here, an example in which the video encoded in each frame at the transmission side application terminal 2A is stored in each media packet and transmitted, and is received by the reception side application terminal 2B via the packet network 5 and reproduced. Will be described. The packet network 5 may be a packet network emulator that can arbitrarily change network characteristics such as packet loss rate, loss pattern, and delay fluctuation of packets. Thereby, various network characteristics can be easily set for the packet network 5, and the packet loss characteristics under an arbitrary packet behavior characteristic can be easily analyzed.

  The quality information acquisition unit 11 of the packet loss characteristic analysis apparatus 1 receives and acquires transmission quality information and reception quality information transmitted in a control packet such as RTCP XR (RTP Control Protocol) from the application terminals 2A and 2B. (Step 110). The quality information acquisition unit 11 collects media packets of the video from a packet transfer device such as a hub (HUB) or a terminal adapter (TAP) provided between the application terminals 2A and 2B and the packet network 5 ( The transmission quality information and the reception quality information may be acquired from these media packets.

  The main quality information included in the acquired transmission quality information includes a sequence number indicating a transmission order, a video frame type, a video frame number, the number of transmission packets, and the number of transmission frames regarding each transmission media packet. The main quality information included in the reception quality information includes a sequence number indicating the transmission order and a delay fluctuation time indicating the arrival time difference from the immediately preceding media packet for each received media packet.

  On the other hand, the quality evaluation acquisition unit 14 acquires a video deterioration evaluation result related to the video received and reproduced by the reception side application terminal 2B from the communication quality evaluation device 3 provided in the reception side application terminal 2B (step 111).

  Next, based on the transmission quality information and the reception quality information acquired by the quality information acquisition unit 11, the video degradation determination unit 12 uses the media application packet transmitted from the transmission application terminal 2A at the reception application terminal 2B. An invalid packet that could not be normally received is determined (step 112).

  Subsequently, the video degradation determination unit 12 executes the above-described video degradation determination process of FIG. 2, and based on the assumed burst determination condition 13 indicating the generation status of invalid packets within an arbitrary invalid packet detection time, The presence / absence of video degradation is determined from the invalid packet for each invalid packet detection time within the video degradation determination period, and the video degradation occurrence time and the number of video degradation detections are output as the video degradation judgment result (step 113).

Thereafter, the burst determination condition determination unit 15 calculates the correct rate of the video degradation determination result obtained from the video degradation determination unit 12 for each different burst determination condition based on the video degradation evaluation result from the quality evaluation acquisition unit 14. The determination result information 16 is stored in the storage unit (step 114).
At this time, the burst determination condition determination unit 15 compares the video degradation detection time and the number of video degradation detections for the video degradation evaluation result and the video degradation judgment result, and obtains a correct score for each video degradation.

  For example, as shown in FIG. 5, if video degradation is detected at the same time in both the video degradation evaluation result and the video degradation determination result, it is determined as “correct” and the correct score is set to “+1”, and the video degradation evaluation result If video degradation is detected as a result of video degradation determination at a time when video degradation is not detected in, it is determined as “false detection”, the correct score is set to “−1”, and video degradation is detected from the video degradation evaluation result. If no video degradation is detected in the video degradation determination result at that time, it is determined as “not detected” and the correct score is set to “0”.

  Then, the correct answer rate is calculated by adding the correct answer scores and dividing the sum by the number of video deterioration detection times of the video deterioration determination result to obtain an average value. In the example of FIG. 5, there are two “correct answers”, one “false detection”, and one “not detected”, so that the total correct score = 1-1 + 0 + 1 = 1, which is the number of detected video results. By dividing by = 3, the correct answer rate = 1/3 = 0.333 is obtained.

  As shown in FIG. 6, the burst determination condition determination unit 15 sets the assumed burst determination condition indicating the highest accuracy rate among the determination result information 16 including the accuracy rates obtained for the different burst determination conditions. The desired burst determination condition 17 is determined and output to the storage unit or the outside of the apparatus (step 115), and the series of packet loss characteristic analysis processing is terminated.

  As described above, in this embodiment, the video degradation determination unit 12 determines an invalid packet that has not been normally received from the media packets based on the transmission quality information and the reception quality information, and an arbitrary invalid packet detection time. On the basis of the assumed burst determination condition 13 indicating the occurrence of invalid packets in the network, the presence / absence of video degradation is determined from invalid packets at each invalid packet detection time within a predetermined video degradation determination period, and the burst determination condition determination unit 15 Based on the video degradation evaluation result from the quality evaluation acquisition unit 14, the correct rate of the video degradation determination result obtained from the video degradation determination unit is calculated for each different burst determination condition, and the assumed burst determination condition indicating the highest correct rate Is determined as the burst determination condition 17

As a result, it is possible to obtain a burst determination condition for accurately distinguishing video degradation that has occurred without obtaining the effect of the FEC function from other video degradation such as video degradation that cannot be perceived by humans.
Therefore, by determining the generation status of invalid packets within an arbitrary invalid packet detection time based on the burst determination condition obtained in the present invention, it is possible to determine whether or not video degradation has occurred without obtaining the effect of the FEC function. The corresponding video communication state can be accurately determined.

  For this reason, it is possible to use an appropriate quality estimation method according to the video communication state, such as selecting a different quality estimation model based on the video communication state, and the loss tolerance against random packet loss is high, and bursty It is possible to accurately estimate the user experience quality even for video communication having a quality degradation characteristic in which the video quality is first degraded due to packet loss.

  Further, in the present embodiment, as the assumed burst determination condition, an assumed burst time for defining the period length of the invalid packet detection time and an assumed burst determination for determining the number of invalid packets detected within the invalid packet detection time Using the pair with the number of packets, the video degradation determination unit 12 continuously provides invalid packet detection times having a period length of the assumed burst time within the video degradation determination period, and the invalid packet detection time within any invalid packet detection time is determined. Since the presence / absence of video deterioration in the invalid packet detection time is determined based on the comparison result between the number of packets and the assumed burst determination packet number, it is possible to determine the presence / absence of video deterioration by a simple process of counting and comparing the number of packets. . Further, an average video deterioration determination result can be obtained for the video deterioration determination period.

  Further, in the present embodiment, each of the deterioration time point determined by the burst determination condition determination unit 15 as having video deterioration by the video deterioration determination result and the deterioration time point evaluated by the video deterioration evaluation result as having video deterioration, Since the comparison of the presence / absence of detection of video degradation in the two is compared, and the correct answer rate is calculated based on the total value of the correct answers according to the comparison result at the time of degradation, the video degradation judgment obtained for each different burst judgment condition The results can be compared and evaluated easily and accurately with a simple process.

[Second Embodiment]
Next, a packet loss characteristic analyzing apparatus according to the second embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a flowchart showing video degradation determination processing in the packet loss characteristic analysis apparatus according to the second exemplary embodiment of the present invention. FIG. 8 is an explanatory diagram showing a video deterioration determination operation in the packet loss characteristic analysis apparatus according to the second embodiment of the present invention.

  In the first embodiment, the case where the invalid packet detection time is continuously provided within the video deterioration determination period has been described as an example of the video deterioration determination process of the packet loss characteristic analysis apparatus 1. In the present embodiment, an example will be described in which an invalid packet detection time is provided with an arbitrary invalid packet as the head within the video deterioration determination period. Note that the present embodiment is the same as the first embodiment in the configuration of the packet loss characteristic analysis apparatus 1 except that the video degradation determination process in the video degradation determination unit 12 is changed. Detailed description is omitted.

In the present embodiment, as an assumed burst determination condition, an assumed burst time for defining the length of the invalid packet detection time, and an assumed burst determination packet number for determining the number of invalid packets detected within the invalid packet detection time. And a pair.
The video degradation determination unit 12 provides an invalid packet detection time having a period length of an assumed burst time of, for example, about 3 minutes from the time of occurrence of an arbitrary invalid packet, and the number of invalid packets and the assumed burst within the invalid packet detection time. Based on the comparison result with the number of determination packets, the presence / absence of video degradation in the invalid packet detection time is determined.

[Operation of Second Embodiment]
In the video degradation determination process of FIG. 7, the video degradation determination unit 12 first acquires an arbitrary assumed burst determination condition 13 from the storage unit (step 120). The assumed burst determination condition 13 is information that is a candidate for the desired burst determination condition 17, and a plurality of assumed burst determination conditions 13 having different values are stored in the storage unit in advance.

  The hypothetical burst determination condition 13 includes information that defines the generation status of invalid packets within the invalid packet detection time. In the present embodiment, as shown in FIG. 8, the video is based on the assumed burst time having a value of, for example, about 10 ms that defines the length of the invalid packet detection time and the number of invalid packets detected within the invalid packet detection time. A combination with the number of assumed burst determination packets consisting of, for example, a value of about 3 packets is used as the assumed burst determination condition 13 for determining the presence or absence of deterioration.

Next, the video degradation determination unit 12 initializes the count value of the number of invalid packets detected within the invalid packet detection time (step 121).
Subsequently, based on the reception quality information and the invalid packet determination result, the video degradation determination unit 12 can normally receive the packet successfully received by the reception-side application terminal 2B within the invalid packet detection time among the transmitted media packets. The processing packets composed of the invalid packets that have not existed are selected one by one in time order. Note that once selected processing packets are not selected again.

Only when the selected processing packet is an invalid packet (step 122: YES), the number of invalid packets is counted (step 123). At this time, only when the number of invalid packets is “1” (step 124: YES), timing of a new invalid packet detection time is started (step 125).
In this way, the video degradation determination unit 12 repeatedly executes Steps 122 to 125 until the invalid packet detection time has elapsed for the assumed burst time (Step 126: NO).

On the other hand, when the invalid packet detection time has elapsed for the assumed burst time in step 126 (step 126: YES), the number of invalid packets is compared with the assumed burst determination packet number (step 127).
Here, only when the number of invalid packets is equal to or greater than the number of assumed burst determination packets (step 127: YES), it is determined that there is video degradation in the invalid packet detection time, and the number of video degradation detections counted so far is 1 At the same time, the start time of the invalid packet detection period is stored in the storage unit as the video degradation occurrence time (step 128).

  After this, if the video deterioration determination period has not ended (step 129: NO), the process returns to step 121 to repeatedly execute the video result determination process for the next invalid packet detection time, and according to the end of the video deterioration determination period. (Step 129: YES), a series of video deterioration determination processing is terminated.

  In the example of FIG. 8, although two invalid packets are detected within the first invalid packet detection time, the number of invalid packets “2” is smaller than the assumed burst determination packet number “T = 3”, so there is no video degradation. It is determined. On the other hand, four invalid packets are detected within the next invalid packet detection time, and the number of invalid packets “4” is equal to or greater than the assumed burst determination packet number “T = 3”, so it is determined that there is video degradation.

  Thus, in the present embodiment, as the assumed burst determination condition 13, the assumed burst time for defining the period length of the invalid packet detection time and the number of invalid packets detected within the invalid packet detection time are determined. Using the set with the number of assumed burst determination packets, the video degradation determination unit 12 provides an invalid packet detection time having a period length of an assumed burst time from the occurrence point of any invalid packet, and invalid packets within the invalid packet detection time. Based on the comparison result between the number of packets and the assumed burst determination packet number, the presence / absence of video degradation in the invalid packet detection time is determined, so the presence / absence of video degradation is determined by a simple process of counting and comparing the number of packets. it can.

  In addition, the invalid packet detection time of fixed length is always provided with the invalid packet as the head, so the invalid packet detection time can be efficiently set in the section where the continuous invalid packet is generated, and the video deterioration determination is performed with high accuracy. be able to.

[Third Embodiment]
Next, a packet loss characteristic analyzing apparatus according to the third embodiment of the present invention will be described with reference to FIG. 9 and FIG. FIG. 9 is a flowchart showing video degradation determination processing in the packet loss characteristic analysis apparatus according to the third exemplary embodiment of the present invention. FIG. 10 is an explanatory diagram showing a video deterioration determination operation in the packet loss characteristic analysis apparatus according to the third embodiment of the present invention.

  In the first embodiment, the case where the invalid packet detection time is continuously provided within the video deterioration determination period has been described as an example of the video deterioration determination process of the packet loss characteristic analysis apparatus 1. In this embodiment, the invalid packet detection time is provided within the video degradation determination period until the number of invalid packet intervals from the occurrence of any invalid packet to the next invalid packet exceeds the assumed packet density determination amount. An example will be described. Note that the present embodiment is the same as the first embodiment in the configuration of the packet loss characteristic analysis apparatus 1 except that the video degradation determination process in the video degradation determination unit 12 is changed. Detailed description is omitted.

In this embodiment, as an assumed burst determination condition, an assumed packet density determination amount that defines the number of invalid packet intervals used for determining the end of invalid packet detection time and the number of invalid packets detected within the invalid packet detection time are determined. A pair with the number of assumed burst decision packets is used.
The video degradation determination unit 12 provides an invalid packet detection time having a period length from the time when any invalid packet occurs to the time when the number of invalid packet intervals from the next invalid packet becomes equal to or greater than the assumed packet density determination amount. Based on the comparison result between the number of invalid packets within the invalid packet detection time and the assumed burst determination packet number, the presence / absence of video degradation in the invalid packet detection time is determined.

[Operation of Third Embodiment]
In the video degradation determination process of FIG. 9, the video degradation determination unit 12 first acquires an arbitrary assumed burst determination condition 13 from the storage unit (step 140). The assumed burst determination condition 13 is information that is a candidate for the desired burst determination condition 17, and a plurality of assumed burst determination conditions 13 having different values are stored in the storage unit in advance.

  The hypothetical burst determination condition 13 includes information that defines the generation status of invalid packets within the invalid packet detection time. In the present embodiment, as shown in FIG. 10, video based on an assumed packet density determination amount that defines the number of invalid packet intervals used for determining the end of invalid packet detection time and the number of invalid packets detected within the invalid packet detection time. A combination with the number of assumed burst determination packets consisting of, for example, a value of about 3 packets is used as the assumed burst determination condition 13 for determining the presence or absence of deterioration.

Next, the video degradation determination unit 12 initializes a count value of the number of invalid packets detected within the invalid packet detection time (step 141).
Subsequently, based on the reception quality information and the invalid packet determination result, the video degradation determination unit 12 can normally receive the packet successfully received by the reception-side application terminal 2B within the invalid packet detection time among the transmitted media packets. The processing packets composed of the invalid packets that have not existed are selected one by one in time order. Note that once selected processing packets are not selected again.

  Only when the selected processing packet is an invalid packet (step 142: YES), the number of invalid packets is counted (step 143). At this time, only when the number of invalid packets is “1” (step 144: YES), a new invalid packet detection time is started (step 145), and the number of invalid packet intervals is initialized (step 146). .

If the selected processing packet is not an invalid packet in step 142 (step 142: NO), and if the number of invalid packets is not “1” in step 144 (step 144: NO), the number of invalid packet intervals Is increased by one (step 147).
In this way, the video deterioration determination unit 12 repeatedly executes Steps 142 to 147 until the number of invalid packet intervals becomes equal to or greater than the assumed packet density determination amount (Step 148: NO).

On the other hand, when the number of invalid packet intervals becomes equal to or greater than the assumed packet density determination amount in step 148 (step 148: YES), the number of invalid packets is compared with the assumed burst determination packet number (step 149).
Here, only when the number of invalid packets is equal to or greater than the number of assumed burst determination packets (step 149: YES), it is determined that there is video degradation in the invalid packet detection time, and the number of video degradation detections counted so far is 1 In addition, the start time of the invalid packet detection period is stored in the storage unit as the video degradation occurrence time (step 150).

  Thereafter, if the video deterioration determination period has not ended (step 151: NO), the process returns to step 141 to repeatedly execute the video result determination process for the next invalid packet detection time, and according to the end of the video deterioration determination period. (Step 151: YES), a series of video deterioration determination processing is completed.

  In the example of FIG. 10, within the first invalid packet detection time, the number of invalid packet intervals until the next invalid packet becomes the assumed packet density determination amount “X = 5” and the invalid packet detection time ends. Since only one invalid packet is detected, and this invalid packet number “1” is smaller than the assumed burst determination packet number “T = 3”, it is determined that there is no video degradation. On the other hand, within the next invalid packet detection time, the number of invalid packet intervals up to the next invalid packet continues as “1”, “1”, “0”, respectively, and the last invalid packet interval number is the assumed packet density determination amount “ X = 5 "and the invalid packet detection time ends. During this time, a total of four invalid packets are detected, and the number of invalid packets “4” is equal to or greater than the assumed burst determination packet number “T = 3”, so that it is determined that there is video degradation.

  Thus, in this embodiment, as the assumed burst determination condition 13, the assumed packet density determination amount that defines the number of invalid packet intervals used for determining the end of the invalid packet detection time, and the invalid packet detected within the invalid packet detection time. The number of invalid packet intervals from the time of occurrence of any invalid packet to the next invalid packet is greater than or equal to the assumed packet density judgment amount by the video degradation determination unit 12 using a set of the assumed burst determination packet number for determining the number. The invalid packet detection time up to the point in time becomes the invalid packet detection time, and the presence or absence of video degradation at the invalid packet detection time is determined based on the comparison result between the number of invalid packets within the invalid packet detection time and the assumed burst determination packet number. Therefore, the presence / absence of video degradation can be determined by a simple process of counting and comparing the number of packets.

  In addition, since the end point of the invalid packet detection time is determined by the number of invalid packet intervals, it is possible to set a variable-length invalid packet detection time according to the occurrence state of invalid packets. As a result, compared to the case of using a fixed-length invalid packet detection time, it is possible to determine video degradation as a single group of consecutive invalid packets that are likely to be perceived as video degradation, with extremely high accuracy. The video degradation determination can be performed with.

[Fourth Embodiment]
Next, a packet loss characteristic analysis apparatus according to the fourth exemplary embodiment of the present invention will be described with reference to FIG. 11 and FIG. FIG. 11 is a block diagram showing a configuration of a packet loss characteristic analyzing apparatus according to the fourth embodiment of the present invention. The same or equivalent parts as those in FIG. FIG. 12 is an explanatory diagram illustrating a determination target packet selection operation in the packet loss characteristic analysis apparatus according to the fourth embodiment of the present invention.

  In the first embodiment, the case has been described as an example in which the video deterioration determination process is performed using all of the media packets and invalid packets normally received by the reception-side application terminal 2B as processing packets. In the present embodiment, a packet to be subjected to video degradation determination processing is selected as a determination target packet according to a frame type corresponding to each media packet, out of packets normally received by the reception-side application terminal 2B and invalid packets. The case will be described.

  Compared to the first embodiment, the packet loss characteristic analysis apparatus 1 according to the present embodiment includes a determination target packet selection unit 18 as a new functional unit. Other configurations in the packet loss characteristic analysis apparatus 1 according to the present embodiment are the same as those in the first embodiment, and a description thereof is omitted here.

  The determination target packet selection unit 18 has a function of determining the frame type of a frame corresponding to the media packet based on the reception quality information, and a determination target packet that is a target of video degradation determination among the media packets based on the frame type And a function of selecting. As for the frame type corresponding to each packet, for example, the frame type of the target frame can be acquired from the header information of the packet included in the transmission quality information.

  In general, when a video is encoded into various frames, the influence on the video quality due to deterioration of each frame differs depending on the content of encoded data included in the frame. For example, in the GOP (Group Of Pictures) configuration of the standard MPEG-2 (ISO / IEC 13818), an I frame including all image data of an image corresponding to the frame, or a past image such as this I frame is used. In the P frame generated by the directional interframe predictive coding, the influence on the video quality due to the deterioration is large. On the other hand, in the B frame generated by the bidirectional inter-frame predictive encoding from past and future images such as I and P frames, the influence on the video quality due to the degradation is relatively small.

In this embodiment, paying attention to the influence on the video quality that is different depending on the frame type, as shown in FIG. 12, the frame type of the frame corresponding to the media packet is determined, for example, I frame, P frame, etc. Only the media packet of the frame type that has a large influence on the video quality due to the degradation is selected as the determination target packet of the video degradation determination process.
As a result, only invalid packets that can be perceived by a human as video degradation can be used as video degradation determination processing, and video degradation determination can be performed with high accuracy.

[Operation of Fourth Embodiment]
Next, the operation of the packet loss characteristic analyzer according to the fourth exemplary embodiment of the present invention will be described with reference to FIG. FIG. 13 is a flowchart showing a video degradation determination process in the packet loss characteristic analysis apparatus according to the fourth embodiment of the present invention. The same or equivalent parts as those in FIG. .
Here, a case where the present embodiment is applied to the video deterioration determination process described in the second embodiment will be described as an example, but the present invention can be similarly applied to other embodiments.

  In the video degradation determination process of FIG. 13, the video degradation determination unit 12 first acquires an arbitrary assumed burst determination condition 13 from the storage unit (step 120). The assumed burst determination condition 13 is information that is a candidate for the desired burst determination condition 17, and a plurality of assumed burst determination conditions 13 having different values are stored in the storage unit in advance.

  The hypothetical burst determination condition 13 includes information that defines the generation status of invalid packets within the invalid packet detection time. In the present embodiment, the presence / absence of video degradation is determined based on a hypothetical burst time consisting of a value of about 10 ms, for example, and the number of invalid packets detected within the invalid packet detection time, which defines the length of the invalid packet detection time. For example, a combination with the assumed burst determination packet number having a value of about 3 packets is used as the assumed burst determination condition 13.

Next, the video degradation determination unit 12 initializes the count value of the number of invalid packets detected within the invalid packet detection time (step 121).
Subsequently, based on the reception quality information and the invalid packet determination result, the video degradation determination unit 12 can normally receive the packet successfully received by the reception-side application terminal 2B within the invalid packet detection time among the transmitted media packets. The processing packets composed of the invalid packets that have not existed are selected one by one in time order. Note that once selected processing packets are not selected again.

  If the selected processing packet is an invalid packet (step 122: YES), it is checked whether the invalid packet is a determination target packet based on the selection result in the determination target packet selection unit 18 to determine If it is not the target packet (step 130: NO), the process proceeds to step 129 described later.

When the invalid packet is a determination target packet (step 130: YES), the number of invalid packets is counted (step 123). At this time, only when the number of invalid packets is “1” (step 124: YES), timing of a new invalid packet detection time is started (step 125).
In this way, the video degradation determination unit 12 repeatedly executes Steps 122 to 125 until the invalid packet detection time has elapsed for the assumed burst time (Step 126: NO).

On the other hand, when the invalid packet detection time has elapsed for the assumed burst time in step 126 (step 126: YES), the number of invalid packets is compared with the assumed burst determination packet number (step 127).
Here, only when the number of invalid packets is equal to or greater than the number of assumed burst determination packets (step 127: YES), it is determined that there is video degradation in the invalid packet detection time, and the number of video degradation detections counted so far is 1 At the same time, the start time of the invalid packet detection period is stored in the storage unit as the video degradation occurrence time (step 128).

  After this, if the video deterioration determination period has not ended (step 129: NO), the process returns to step 121 to repeatedly execute the video result determination process for the next invalid packet detection time, and according to the end of the video deterioration determination period. (Step 129: YES), a series of video deterioration determination processing is terminated.

  As described above, in this embodiment, the determination target packet selection unit 18 determines the frame type of the frame corresponding to the media packet based on the reception quality information, and the video degradation of the media packet based on the frame type. Since the video degradation determination unit 12 determines the presence or absence of video degradation from the invalid packet selected as the judgment target packet among the invalid packets, the video degradation determination unit 12 determines that the video degradation has occurred. Only invalid packets that can be perceived can be used as video degradation determination processing, and video degradation determination can be performed with high accuracy.

[Fifth Embodiment]
Next, a packet loss characteristic analyzing apparatus according to the fifth embodiment of the present invention will be described with reference to FIG. FIG. 14 is a flowchart showing invalid packet determination processing in the packet loss characteristic analyzer according to the fifth exemplary embodiment of the present invention.

In the present embodiment, a specific example of invalid packet determination processing in the video deterioration determination unit 12 of the first embodiment described above will be described.
First, the video degradation determination unit 12 arbitrarily selects an undetermined transmission media packet from the transmission quality information (step 160), and confirms whether or not the same media packet as the sequence number is received with the reception quality information ( Step 161). Here, if the same media packet as the sequence number has not been received (step 161: NO), the media packet is an invalid packet because it can be determined that the media packet is a lost packet lost in the transmission path on the way. (Step 165).

  On the other hand, if the same media packet as the sequence number has been received (step 161: YES), the delay fluctuation time of the transmission media packet is confirmed with the reception quality information, and the allowable delay time of the real-time application Compare (step 162). Here, when the delay fluctuation time exceeds the allowable delay time (step 162: NO), it can be determined that the media packet is a late arrival packet that arrives with a delay in the transmission path or terminal. Therefore, it is determined that the packet is invalid (step 165).

  On the other hand, when the delay fluctuation time is equal to or shorter than the allowable delay time (step 162: YES), only when the real-time application considers the arrival order reversed packet as a loss (step 163: YES), and the media packet It is confirmed from the reception quality information whether the order of arrival and the sequence number match. If the packet cannot be confirmed and the arrival order is reversed (step 164: YES), it is determined that the packet is an invalid packet (step 165).

When the arrival order is not reversed (step 164: NO), or when the real-time application does not regard the arrival order reversed packet as a loss (step 163: NO), it is determined that the packet is not an invalid packet. (Step 166).
In this way, after the invalid packet determination is performed on the selected transmission media packet, if there is a transmission packet that has not been determined to be invalid (step 167: YES), the process returns to step 160 described above. The invalid packet determination for the remaining received media packets is repeated. On the other hand, when the invalid packet determination is completed for all the transmission media packets (step 167: NO), the series of invalid packet determination processing ends.

  Thus, in this embodiment, among the media packets whose transmission is confirmed by the transmission quality information by the video degradation determination unit 12, the media packets whose reception quality information is not confirmed, and the reception quality information Media packets whose arrival time difference from the previous media packet obtained from the arrival time of each media packet exceeds the allowable packet delay time of the application are judged as invalid packets. Packets lost due to arrival can also be determined as invalid packets, and packets that cannot be reproduced as media by the real-time application on the receiving side can be accurately determined.

  In addition, since the video degradation determination unit 12 determines that the media packet whose reception order is inconsistent with the transmission order of the media packet confirmed by the reception quality information is an invalid packet, the real-time application arrives. When it is considered that the order-reversed packet is a loss, it is possible to more accurately determine a packet that cannot be reproduced as media by the receiving-side real-time application.

[Extension of each embodiment]
In each of the above-described embodiments, the packet loss characteristic analysis device 1 sends transmission / reception quality information and video degradation evaluation results necessary for packet loss characteristic analysis processing from the application terminals 2A and 2B and the communication quality evaluation device 3 in real time during media transmission. Although the case where it acquires by (online) was demonstrated as an example, it is not limited to this. For example, transmission / reception quality information and video degradation evaluation results necessary for packet loss characteristic analysis processing are measured in advance by an arbitrary measurement system, and thereafter (offline) these data are input to the packet loss characteristic analysis apparatus 1. Also good.

  Further, when the packet loss characteristic analysis device 1 acquires transmission / reception quality information and video degradation evaluation results necessary for packet loss characteristic analysis processing in real time (online) at the time of media transmission, the video to be transmitted from the transmission-side application terminal 2A is obtained. The packet loss characteristic analysis apparatus 1 has a function of instructing selection, a function of instructing predetermined packet behavior characteristics to the packet network 5 including a packet network emulator, and a function of evaluating video degradation at the receiving-side application terminal 2B. You may prepare.

It is a block diagram which shows the structure of the packet loss characteristic analysis apparatus concerning the 1st Embodiment of this invention. It is a flowchart which shows the video degradation determination process in the packet loss characteristic analysis apparatus concerning the 1st Embodiment of this invention. It is explanatory drawing which shows the image | video degradation determination operation | movement of FIG. It is a flowchart which shows the packet loss characteristic analysis process in the packet loss characteristic analysis apparatus concerning the 1st Embodiment of this invention. It is explanatory drawing which shows correct rate calculation operation | movement. It is explanatory drawing which shows burst condition determination operation | movement. It is a flowchart which shows the video degradation determination process in the packet loss characteristic analysis apparatus concerning the 2nd Embodiment of this invention. It is explanatory drawing which shows the image | video degradation determination operation | movement of FIG. It is a flowchart which shows the video degradation determination process in the packet loss characteristic analyzer concerning the 3rd Embodiment of this invention. It is explanatory drawing which shows the image | video degradation determination operation | movement of FIG. It is a block diagram which shows the structure of the packet loss characteristic analyzer concerning the 4th Embodiment of this invention. It is explanatory drawing which shows determination object packet selection operation | movement. It is a flowchart which shows the video degradation determination process in the packet loss characteristic analysis apparatus concerning the 4th Embodiment of this invention. It is a flowchart which shows the invalid packet determination process in the packet loss characteristic analysis apparatus concerning the 5th Embodiment of this invention. It is explanatory drawing which shows the effect of a FEC function.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Packet loss characteristic analyzer, 11 ... Quality information acquisition part, 12 ... Image | video degradation determination part, 13 ... Assumed burst determination condition, 14 ... Quality evaluation acquisition part, 15 ... Burst determination condition determination part, 16 ... Determination result information, DESCRIPTION OF SYMBOLS 17 ... Burst determination conditions, 18 ... Determination object packet selection part, 2, 2A, 2B ... Application terminal, 3 ... Communication quality evaluation apparatus, 5 ... Packet network.

Claims (10)

By analyzing the loss characteristics of media packets used for video communication between the transmission side and reception side application terminals connected via the packet network, the burst of media packets that cause degradation of the video quality is analyzed. A packet loss characteristic analyzer that outputs a burst determination condition for determining loss,
Quality information for acquiring transmission quality information indicating the transmission status of the media packet transmitted from the transmission application terminal and reception quality information indicating the reception status of the media packet received by the reception application terminal An acquisition unit;
A quality evaluation acquisition unit for acquiring an evaluation result relating to deterioration of the video reproduced by the reception-side application terminal;
Based on the transmission quality information and the reception quality information, an invalid packet that cannot be normally received by the receiving application terminal among the media packets is determined, and an invalid packet occurrence status within an arbitrary invalid packet detection time is determined. A video degradation determination unit that determines the presence or absence of video degradation from the invalid packet for each invalid packet detection time within a predetermined video degradation determination period based on the assumed burst determination condition shown;
Based on the video degradation evaluation result from the quality assessment acquisition unit, the correct burst rate of the video degradation determination result obtained from the video degradation determination unit is calculated for each different burst determination condition, and the assumed burst determination condition indicating the highest correct rate A packet loss characteristic analyzing apparatus comprising: a burst determination condition determination unit that determines a burst determination condition as a burst determination condition. The packet loss characteristic analysis apparatus according to claim 1,
The assumed burst determination condition is a set of an assumed burst time for defining a period length of the invalid packet detection time and an assumed burst determination packet number for determining the number of invalid packets detected within the invalid packet detection time. Consists of
The video degradation determination unit continuously provides invalid packet detection times having a period length of the assumed burst time within the video degradation determination period, and the number of invalid packets within an arbitrary invalid packet detection time and the assumed burst determination. Based on the comparison result with the number of packets, determine the presence or absence of video degradation during the invalid packet detection time,
The burst determination condition determination unit calculates the correct rate of the video degradation determination result obtained from the video degradation determination unit for each assumed burst condition including a set of various assumed burst times and the number of assumed burst determination packets, and obtains the highest correct answer. A packet loss characteristic analyzing apparatus characterized in that a set of an assumed burst time indicating a rate and the number of assumed burst decision packets is output as the burst decision condition. The packet loss characteristic analysis apparatus according to claim 1,
The assumed burst determination condition is a set of an assumed burst time for defining a period length of the invalid packet detection time and an assumed burst determination packet number for determining the number of invalid packets detected within the invalid packet detection time. Consists of
The video degradation determination unit provides an invalid packet detection time having a period length of the assumed burst time from the occurrence point of any invalid packet, and the number of invalid packets within the invalid packet detection time and the number of assumed burst determination packets On the basis of the comparison result of whether or not there is video degradation in the invalid packet detection time,
The burst determination condition determination unit calculates the correct rate of the video degradation determination result obtained from the video degradation determination unit for each assumed burst condition including a set of various assumed burst times and the number of assumed burst determination packets, and obtains the highest correct answer. A packet loss characteristic analyzing apparatus characterized in that a set of an assumed burst time indicating a rate and the number of assumed burst decision packets is output as the burst decision condition. The packet loss characteristic analysis apparatus according to claim 1,
The assumed burst determination condition includes an assumed packet density determination amount that defines the number of invalid packet intervals used for determining the end of the invalid packet detection time, and an assumed burst for determining the number of invalid packets detected within the invalid packet detection time. It consists of a set with the number of judgment packets,
The video degradation determination unit sets an invalid packet detection time from an occurrence time of an arbitrary invalid packet to a time when the number of invalid packet intervals from the next invalid packet becomes equal to or greater than the assumed packet density determination amount, and the invalid packet detection time. Determining the presence or absence of video degradation in the invalid packet detection time based on the comparison result between the number of invalid packets in the assumed burst determination packet number,
The burst determination condition determination unit calculates a correct answer rate of the video degradation determination result obtained from the video degradation determination unit for each assumed burst condition including a set of various assumed packet density determination amounts and the number of assumed burst determination packets, A packet loss characteristic analysis apparatus characterized in that a set of a hypothetical packet density judgment amount and a hypothetical burst judgment packet number showing a high accuracy rate is output as the burst judgment condition. The packet loss characteristic analysis apparatus according to claim 1,
The burst determination condition determination unit is configured to detect video deterioration at both of a deterioration time point determined to be video deterioration based on the video deterioration determination result and a deterioration time point determined to be video deterioration based on the video deterioration evaluation result. A packet loss characteristic analyzing apparatus that compares presence / absence and calculates the correct answer rate based on a total value of correct answer scores according to the comparison result at the time of deterioration. The packet loss characteristic analysis apparatus according to claim 1,
A determination target packet that determines a frame type of a video corresponding to the media packet based on the reception quality information, and selects a determination target packet that is a target of video degradation determination among the media packets based on the frame type A selection unit,
The packet loss characteristic analysis apparatus, wherein the video deterioration determination unit determines presence / absence of video deterioration from an invalid packet selected as the determination target packet among the invalid packets. The packet loss characteristic analysis apparatus according to claim 1,
The video degradation determination unit is configured such that, among media packets whose transmission is confirmed with the transmission quality information, a media packet whose reception is not confirmed with the reception quality information, and an arrival interval of each media packet of the reception quality information A packet loss characteristic analyzing apparatus characterized in that a media packet whose delay fluctuation time indicates an allowable packet delay time of the application is determined as the invalid packet. The packet loss characteristic analysis apparatus according to claim 1,
The packet loss characteristic analysis device, wherein the video degradation determination unit determines that a media packet whose transmission order and reception order of media packets confirmed to be received by the reception quality information are inconsistent is the invalid packet. By analyzing the loss characteristics of media packets used for video communication between the transmission side and reception side application terminals connected via the packet network, the burst of media packets that cause degradation of the video quality is analyzed. A packet loss characteristic analysis method used in a packet loss characteristic analysis apparatus that outputs a burst determination condition for determining loss,
Transmission quality information indicating the transmission status of the media packet transmitted from the transmission-side application terminal by the quality information acquisition unit, and reception quality information indicating the reception status of the media packet received at the reception-side application terminal And a quality information acquisition step,
A quality evaluation acquisition step for acquiring an evaluation result related to deterioration of the video reproduced by the receiving application terminal by a quality evaluation acquisition unit;
Based on the transmission quality information and the reception quality information, the video degradation determination unit determines an invalid packet that could not be normally received by the receiving application terminal among the media packets, and within an arbitrary invalid packet detection time A video degradation determination step for determining presence / absence of video degradation from the invalid packet for each invalid packet detection time within a predetermined video degradation determination period based on an assumed burst determination condition indicating an occurrence state of invalid packets;
Based on the video deterioration evaluation result from the quality evaluation acquisition unit, the burst determination condition determination unit calculates the correct rate of the video deterioration determination result obtained from the video deterioration determination unit for each different burst determination condition, and the highest correct answer A packet loss characteristic analysis method comprising: a burst determination condition determination step for determining an assumed burst determination condition indicating a rate as the burst determination condition. By analyzing the loss characteristics of media packets used for video communication between the transmission side and reception side application terminals connected via the packet network, the burst of media packets that cause degradation of the video quality is analyzed. To the computer of the packet loss characteristic analyzer that calculates the burst judgment condition for judging the loss,
Transmission quality information indicating the transmission status of the media packet transmitted from the transmission-side application terminal by the quality information acquisition unit, and reception quality information indicating the reception status of the media packet received at the reception-side application terminal And a quality information acquisition step,
A quality evaluation acquisition step for acquiring an evaluation result related to deterioration of the video reproduced by the receiving application terminal by a quality evaluation acquisition unit;
Based on the transmission quality information and the reception quality information, the video degradation determination unit determines an invalid packet that could not be normally received by the receiving application terminal among the media packets, and within an arbitrary invalid packet detection time A video degradation determination step for determining presence / absence of video degradation from the invalid packet for each invalid packet detection time within a predetermined video degradation determination period based on an assumed burst determination condition indicating an occurrence state of invalid packets;
Based on the video deterioration evaluation result from the quality evaluation acquisition unit, the burst determination condition determination unit calculates the correct rate of the video deterioration determination result obtained from the video deterioration determination unit for each different burst determination condition, and the highest correct answer A burst determination condition determining step for determining an assumed burst determination condition indicating a rate as the burst determination condition.

Images