STREAM LABS Alarms of Stream MultiScreen monitoring system Version 1.0, June 2013.
Version history Version Author Comments 1.0 Krupkin V. Initial version of document. Alarms for MPEG2 TS, RTMP, HLS, MMS, HD- SDI/SDI, CVBS streams and signals. 1
Content Alarms of Stream MultiScreen monitoring system... 4 Common parameters of alarms... 4 Parameters of alarms and logging... 4 Visualization parameters... 5 MPEG2 stream TS and HTTP Live Streaming... 7 HLS Transport error... 7 Low throughput... 7 Sync loss... 7 TR-290 Sync loss... 8 TR-290 sync byte error... 8 TR-290 transport error... 8 TR-290 PAT sections loss... 8 TR-290 PAT sections error... 9 Service lost... 9 TR290 PMT sections loss... 9 TR-290 PMT sections error... 10 TR-290 PCR discontinuity indicator... 10 PID Lost... 10 TR-290 continuity counter error... 10 PID Scrambled... 10 Decoder runtime error... 11 Black video... 11 Frozen video... 11 Audio signal level: overload... 11 Audio signal level: silence... 12 Transport stream bit rate... 12 Service bit rate... 12 RTMP streams... 13 Signal loss... 13 PID Lost... 13 Decoder runtime error... 13 Black video... 14 Frozen video... 14 2
Audio signal level: overload... 14 Audio signal level: silence... 14 Transport stream bit rate... 15 MMS streams... 15 Low throughput... 15 Signal loss... 16 PID Lost... 16 Black video... 16 Frozen video... 17 Audio signal level: overload... 17 Audio signal level: silence... 17 Transport stream bit rate... 18 SDI/HD-SDI and CVBS signals... 18 Signal loss... 18 Black video... 19 Frozen video... 19 Audio signal level: overload... 19 Audio signal level: silence... 20 3
Alarms of Stream MultiScreen system Stream MultiScreen is able to signal when alarms detected. Visual and audio signals are supported. All reports with alarms are being saved into database. Depending on type of input signal the system detects various events. Table below shows these dependencies. Event Data streams MPEG2 TS RTMP HLS MMS SDI/HD-SDI CVBS HLS Transport error X Low throughput X X Sync loss X X TR-290 TS sync loss X X Signal loss X X X X TR-290 sync byte error X X TR-290 transport error X X TR-290 PAT sections loss X X TR-290 PAT sections error X X Service lost X X TR290 PMT sections loss X X TR-290 PMT sections error X X TR-290 PCR discontinuity X X indicator PID lost X X X X TR-290 continuity counter error X X PID Scrambled X X Decoder runtime error X X X Black video X X X X X X Frozen video X X X X X X Audio signal level: overload X X X X X X Audio signal level: silence X X X X X X Transport stream bit rate X X X X Service bit rate X X Common parameters of alarms Parameters of alarms and logs Stream MultiScreen supports following signals about detected alarms: Visualization of alarms on monitoring composition of MultiScreen server; Logging of events in database; Visualization of alarms in MultiMonitor monitoring system; Email notification about alarms; SNMP notifications. 4
Stream MultiScreen allows excluding from monitoring unneeded alarms. Parameters for control of alarms and logs are in a table below: Table 1. Parameters of alarms and logs Description Default value Comment Database logging True Turns logging into database ON and OFF. DB Accumulation 120 Sets time interval (in sec) for placing records into DB. During period this interval records are being accumulated in cash memory. Visualization True Turns alarm visualization on Stream MultiScreen server ON and OFF. Monitoring True Turns On and OFF notifications, sent to Stream MultiMonitor via SNMP protocol. Send e-mail False Turns email notifications ON and OFF. Target mail Email distribution list. ; is a default delimiter. Note: «MultiScreen SNMP Agent» module has to be installed for correct delivery of SNMP notifications. Note: settings for SMTP server in «Mail robot» setup have to be done for correct email notifications. Visualization parameters Visualization of alarm on Stream MultiScreen server is represented by text box with alarm and framed video or/and audio indicators as shown on Fig. 1. Fig. 1 Alarm visualization Monitoring system allows changing events visualization settings. Table 2 presents visualization parameters and their description. 5
Table 2. Visualization parameters Parameter Description Opacity Transparency of box. Could be from 0 to 1. Background Background color in a box. Foreground Font color. Border color Color of frame. Border thickness Thickness of frame. Could be from 0 to 10. Blink Blinking of frame is ON/OFF. Note: «MultiScreen SNMP Agent» module has to be installed for correct delivery of SNMP notifications. 6
MPEG2 TS streams and HTTP Live Streaming HLS Transport error This error reports a problem with delivery of data packet in HLS stream. It occurs when response on HTTP request is not OK. Reasons could be, for instance, incorrect stream address, incorrect settings for proxy server, insufficient broad band, etc. For detailed diagnostics of error it is recommended to launch «Stream MultiMonitor» application in design mode, establish connection with server, which generates an error and open «Output» window. «Output» window will display error message with detailed description upon for occurrence of «HLS Transport error». Note: this alarm is being generated only by HTTP Live Streaming. Low throughput This error reports insufficient broad band of input channel. During formation of HLS stream an input transport stream is being buffered, gets split on fragments and every fragment is being saved on broadcast server as a separate file. Duration of each fragment is being saved too. MultiScreen server in its turn receives from broadcast server current list of fragments in form of HTTP URLs along with information about duration of each fragment. According to spec, duration of each fragment is about 10 seconds. «Low throughput» error is being generated if load time of fragment exceeds duration of fragment, meaning, that server does not keep up with download speed. Note: if download speed of MultiScreen server is constantly lower than speed of broadcast (server), then delay of load of fragments on MultiScreen side will be increasing. On other hand, lifespan of storage on a server is limited and fragments are being removed from server upon expiration. Eventually it comes to the point, when MultiScreen server requests fragment which does not already exist on broadcast server. Interruption in data flow occurs, what could lead to reception, decoding and play back errors and «HLS Transport error» is being generated. Note: this type of alarm is being set only for HTTP Live Streaming. Sync loss This error reports missing input data during designated period of time. Among the reasons could be parameters, which have been set incorrectly for the stream, problems with data delivery, missing ASI input data. As for HTTP Live Streaming, the reason could be parameters, incorrectly set for proxy server. In this case «HLS Transport error» will be generated. 7
Table 3. Parameters of «Sync loss» alarm Parameter Default value Description Timeout 1000 Minimal time interval (in Millisecond), during which data is not received by server. TR-290 Sync loss This error reports loss of synchronization with MPEG-2 transport stream. With every occurrence of this error, events counter increments. Standard ISO/IEC 13818-1, chapter G.01 states, that synchronization is considered successful upon synchronization of 5 bytes in succession in MPEG-2 transport packets. Error can be caused by poor signal reception, problem with the source of signal or if MultiScreen receives signal, which is distinct from MPEG2-TS. TR-290 sync byte error This error reports reception of transport packet with incorrect synchronization byte. Error appears, if after reception of 188 or 204 bytes of transport stream, synchronization byte (0x47) is missing. On contrary to «TR-290 Sync loss», this error indicates single interruption in reception of transport packets. Error can be caused by poor signal reception, problem with the source of signal. TR-290 transport error This error reports, that packet with flag «transport_error_indicator» has been received. Flag «transport_error_indicator» could be set by receiver, if error in data reception has been detected. In this case server increments alarm counter and stops further processing of this packet. Error can be caused by poor signal reception, problem with the source of signal. TR-290 PAT sections loss This error reports absence of some PAT sections in the stream during designated time interval. This interval in defined by «Timeout» parameter. Transport stream carries PAT, which lists all services, included in a stream. If table is missing, none of the services could be decoded. Error can be caused by incorrect transport stream, poor signal reception, problem with the source of signal. 8
Table 4. Parameters of «TR-290 PAT sections loss» alarm Parameter Default value Description Timeout 500 Minimal time interval for missing PAT (in milliseconds). Note: In order to avoid false alarms for HTTP Live Streaming it is recommended to set «Timeout» to 10-12 seconds (default value for MPEG-2 is 500 milliseconds). According to the spec, PAT and PMT tables are transmitted only in the beginning of data chunk with duration around 10 seconds. TR-290 PAT sections error This error reports incorrect section of PAT. Transport stream carries PAT, which lists all services, included in a stream. Error is generated if table is encrypted; or sections include incorrect program IDs. Error can be caused by incorrect transport stream, poor signal reception, problem with the source of signal. Service lost This error reports that required service is missing from PAT. After every update of PAT, MultiScreen server checks presence of all services, which have been added for monitoring. Error is generated if any service is not found. Error can be caused by changes in a list of services, incorrect transport stream, poor signal reception, problem with the source of signal. TR-290 PMT sections loss This error reports absence of some PMT sections in the stream during designated time interval. This interval in defined by «Timeout» parameter. Transport stream carries PMT, which lists all elementary streams, included in a service. If table is missing, the services cannot be decoded. Error can be caused by incorrect transport stream, poor signal reception, problem with the source of signal. Table 5. Parameters of «TR290 PMT sections loss» alarm Parameter Default value Description Timeout 500 Minimal time interval for missing PAT (in milliseconds). Note: In order to avoid false alarms for HTTP Live Streaming it is recommended to set «Timeout» to 10-12 seconds (default value for MPEG-2 is 500 milliseconds). According to the spec, PAT and PMT tables are transmitted only in the beginning of data chunk with duration around 10 seconds. TR-290 PMT sections error This error reports incorrect section of PMT. Transport stream carries PMT, which lists all elementary streams, included in a service. Error is generated if table is encrypted; or sections include incorrect IDs. 9
Error can be caused by incorrect transport stream, poor signal reception, problem with the source of signal. TR-290 PCR discontinuity indicator This error reports incorrect time markers during reception of the stream. Every stream carries time markers (PCR) of base marker, used for playback of elementary streams. Error is generated if time interval between two markers in succession is greater than designated range; and header of stream does not carry discontinuity_indicator flag. This error can be caused by incorrect transport stream, poor signal reception, problem with the source of signal. Table 6. Parameters of «TR-290 PCR discontinuity indicator» alarm Parameter Default value Description Threshold 100 Maximal time interval between two markers in succession with NO discontinuity_indicator (in milliseconds). PID Lost Error reports, that elementary stream is missing from PMT. After every update of PMT, MultiScreen server checks presence of elementary streams, which have been added for monitoring. Error is generated if required elementary stream is not found. Error can be caused by changes in a structure of service, incorrect transport stream, poor signal reception, incorrect settings for multiplexor. TR-290 continuity counter error This error reports incorrect sequence of packets in elementary stream. Error is generated if there are detected repetitions, loss or incorrect sequence of transport packets. Error can be caused by poor reception, incorrect network settings or incorrect settings for source of stream. PID Scrambled This error reports, that elementary stream is encrypted or scrambled. Error can be caused by either malfunction or missing CA module in equipment for source of stream. Table 7. Parameters of «PID Scrambled» alarm Parameter Default value Description Timeout 0 Minimal time interval for reception of scrambled packets (in milliseconds). If value is equal 0, then reception of one scrambled packet is sufficient for error generation. 10
Decoder runtime error This error reports about problem with decoding of elementary stream. Stream MultiScreen server decodes input audio/video streams for analyzing and displaying on a screen. If, for any reason, decoder cannot decode frame, «Decoder runtime error» is being generated. Error can be caused by poor reception, loss of packets, problem with decoders, which are part of MultiScreen server. Black video This error reports, that input stream contains black frame during designated time interval. Error can be caused by black frame in broadcast stream, malfunction in equipment, transmitting signal. Table 8. Parameters of «Black video» alarm Parameter Default value Description Black period 12 seconds Minimal duration of black frame, sufficient for error generation. Black level 16 Level of brightness. Values from 0 to 255. Black threshold 0.01 Lower value corresponds to higher sensitivity of algorithm for processing of noise, present in analyzed stream. Note: default parameters can be defined for any video stream. In order to do that, select decoder from Frozen video This error reports still picture in input stream during designated time interval. Error can be caused either by static picture in input signal; by malfunction in equipment, transmitting signal. Table 9. Parameters of «Frozen video» alarm Parameter Default value Description Frozen period 12 seconds Minimal duration of still picture, sufficient for error generation Frozen threshold 0.03 Lower value corresponds to higher sensitivity of algorithm for processing of noise, present in analyzed stream. Note: default parameters can be defined for any video stream. In order to do that, select decoder from Audio signal level: overload This error reports, that audio level in input stream exceeded designated threshold. Error can be caused by over amplification; by errors in decoding. Table 10. Parameters of «Audio signal level: overload» alarm Overload threshold, dbfs -0.1 Allowed threshold for audio level. Values from -90 to 0 Note: default parameters can be defined for any audio stream. In order to do that, select decoder from 11
Audio signal level: silence This error reports, that audio level in input stream HAS NOT exceeded designated threshold during designated time interval. Error can be caused by silence during broadcast; by malfunction in equipment, which is source of audio. Table 11. Parameters of «Audio signal level: silence» alarm Silence period 12 Time interval when audio level is below designated threshold (in seconds). Silence threshold, -0.1 Audio level (in dbfs). Values from -90 to 0. dbfs Note: default parameters can be defined for any audio stream. In order to do that, select decoder from Transport stream bit rate This error reports, that bit rate of input stream is beyond of predefined range. MultiScreen server computes average bit rate and compares it with preset threshold values. Error is generated if bit rate of input stream is beyond of predefined range. Error can be caused by problems with broadband; by malfunction in equipment, which is source of audio. Table 12. Parameters of «Transport stream bit rate» alarm Parameters Default Description value Bit rate False Turn event detection ON/OFF. enabled Bit rate period 8 seconds Time interval for computation of average bit rate (in seconds). Threshold, high 0 Top threshold (in kbit/sec). Error is generated if it is exceeded. It is disabled if value set to 0. Threshold, low 0 Bottom threshold (in kbit/sec). Error is generated is it is not reached. It is disabled if value set to 0. Note: parameters for this alarm are being set in properties for the stream. By default, detection is disabled. Service bit rate This error reports, that bit rate of input stream of given service is beyond of predefined range. MultiScreen server computes average bit rate across all streams, included in a service, and compares it with preset threshold values. Error is generated if bit rate of input stream is beyond of predefined range. Error can be caused by problems with broadband; by malfunction in equipment, which is source of audio. 12
Table 13. Parameters of Service bit rate» alarm Bit rate False Detection is ON/OFF. enabled Bit rate 8 seconds Time interval for computation of average bit rate (in seconds). period Threshold, high 0 Top threshold (in kbit/sec). Error is generated if it is exceeded. It is disabled if value set to 0. Threshold, low 0 Bottom threshold (in kbit/sec). Error is generated is it is not reached. It is disabled if value set to 0. Note: parameters for this alarm are being set in properties for the stream. By default, detection is disabled. RTMP Streams Signal loss This error reports missing input data during predefined time interval. Parameter «Timeout» sets the value. Cause for this error for RTMP streams could be incorrect address of the stream, corporate security systems, problem with access to broadcast server. Also, it could be caused by timed out connection session between MultiScreen and broadcast servers. «Output» window of Stream MultiMonitor displays all error messages. Table 14. Parameters of «Signal loss» alarm Timeout 1000 Minimal time interval for missing data (in milliseconds). PID Lost This error reports missing elementary data stream (audio or video) during predefined time period. Cause can be change of broadcast format, issues with broadcasting server. Table 15. Parameters of «PID loss» alarm Timeout 1000 Minimal time interval for missing data (in milliseconds). Decoder runtime error This error reports about problem with decoding of elementary stream. Stream MultiScreen server decodes input audio/video streams for analyzing and displaying on a screen. If, for any reason, decoder cannot decode frame, «Decoder runtime error» is being generated. Error can be caused by poor reception, loss of packets, problem with decoders, which are part of MultiScreen server. 13
Black video This error reports, that input stream contains black frame during designated time interval. Error can be caused by black frame in broadcast stream, malfunction in equipment, transmitting signal. Table 16. Parameters of «Black video» alarm Black period 12 seconds Minimal duration of black frame, sufficient for error generation. Black level 16 Level of brightness. Values from 0 to 255. Black threshold 0.01 Lower value corresponds to higher sensitivity of algorithm for processing of noise, present in analyzed stream. Note: default parameters can be defined for any video stream. In order to do that, select decoder from Frozen video This error reports still picture in input stream during designated time interval. Error can be caused either by static picture in input signal; by malfunction in equipment, transmitting signal. Table 17. Parameters of «Frozen video» alarm Frozen period 12 seconds Minimal duration of still picture, sufficient for error generation Frozen threshold 0.03 Lower value corresponds to higher sensitivity of algorithm for processing of noise, present in analyzed stream. Note: default parameters can be defined for any video stream. In order to do that, select decoder from Audio signal level: overload This error reports, that audio level in input stream exceeded designated threshold. Error can be caused by over amplification; by errors in decoding. Table 18. Parameters of «Audio signal level: overload» alarm Overload threshold, dbfs -0.1 Allowed threshold for audio level. Values from -90 to 0 Note: default parameters can be defined for any audio stream. In order to do that, select decoder from Audio signal level: silence This error reports, that audio level in input stream HAS NOT exceeded designated threshold during designated time interval. Error can be caused by silence during broadcast; by malfunction in equipment, which is source of audio. 14
Table 19. Parameters of «Audio signal level: silence» alarm Silence period 12 Time interval when audio level is below designated threshold (in seconds). Silence threshold -0.1 Audio level (in dbfs). Values from -90 to 0. Note: default parameters can be defined for any audio stream. In order to do that, select decoder from Transport stream bit rate This error reports, that bit rate of input stream is beyond of predefined range. MultiScreen server computes average bit rate and compares it with preset threshold values. Error is generated if bit rate of input stream is beyond of predefined range. Error can be caused by problems with broadband; by malfunction in equipment, which is source of audio. Table 20. Parameters of «Transport stream bit rate» alarm Bit rate False Detection is ON/OFF. enabled Bit rate 8 Time interval for computation of average bit rate (in seconds). period Threshold, high 0 Top threshold (in kbit/sec). Error is generated if it is exceeded. It is disabled if value set to 0. Threshold, low 0 Bottom threshold (in kbit/sec). Error is generated is it is not reached. It is disabled if value set to 0. Note: parameters for this alarm are being set in properties for the stream. By default, detection is disabled. MMS Streams Low throughput This error reports insufficient broad band of input channel. MMS broadcast server periodically (usually every second) transmits Optimal Bit rate, which quantifies optimal bit rate for broadcast without delays, caused by buffering, and without skipping frames on a client side. MultiScreen server, in its turn, computes actual current bit rate and if actual is lower than Optimal Bit rate, error «Low throughput» is being generated. Error can be caused by broadband channel or some specific settings on broadcast server - for instance use of VBR or MBR coding. 15
Table 21. Parameters of «Low throughput» alarm Throughput False Detection is ON/OFF. enabled Threshold 90 Parameter allows decrease sensitivity of detector to fluctuations of difference between actual and optimal bit rates (in % points). Note: parameters for this alarm are being set in properties for MMS stream. By default, detection is disabled Signal loss This error reports missing input data during predefined time interval. Parameter «Timeout» sets the value. Cause for this error for RTMP streams could be incorrect address of the stream, corporate security systems, problem with access to broadcast server. Also, it could be caused by timed out connection session between MultiScreen and broadcast servers. «Output» window of Stream MultiMonitor displays all error messages. Table 22. Parameters of «Signal loss» alarms Timeout 1000 Minimal time interval for missing data (in milliseconds). Note: since connecting to MMS server may take considerable amount of time (30 seconds and up), it is recommended setting value to increasingly substantial values. PID Lost This error reports missing elementary stream (audio or video) during predefined time interval. Error can be caused change in broadcast format, malfunction of broadcasting server. Table 23. Parameters of «PID loss» alarm Timeout 1000 Minimal time interval for missing input data (in milliseconds). Black video This error reports, that input stream contains black frame during designated time interval. Error can be caused by black frame in broadcast stream, malfunction in equipment, transmitting signal. 16
Table 24. Parameters of «Black video» alarm Black period 12 Minimal duration of black frame, sufficient for error generation. Black level 16 Level of brightness. Values from 0 to 255. Black threshold 0.01 Lower value corresponds to higher sensitivity of algorithm for processing of noise, present in analyzed stream. Note: default parameters can be defined for any video stream. In order to do that, select decoder from Frozen video This error reports still picture in input stream during designated time interval. Error can be caused either by static picture in input signal; by malfunction in equipment, transmitting signal. Table 25. Parameters of «Frozen video» alarm Frozen period 12 Minimal duration of still picture, sufficient for error generation Frozen threshold 0.03 Lower value corresponds to higher sensitivity of algorithm for processing of noise, present in analyzed stream. Note: default parameters can be defined for any video stream. In order to do that, select decoder from Audio signal level: overload This error reports, that audio level in input stream exceeded designated threshold. Error can be caused by over amplification; by errors in decoding. Table 26. Parameters of «Audio signal level: overload» alarm Overload threshold -0.1 Allowed threshold for audio level. Values from -90 to 0 Note: default parameters can be defined for any audio stream. In order to do that, select decoder from Audio signal level: silence This error reports, that audio level in input stream HAS NOT exceeded designated threshold during designated time interval. Error can be caused by silence during broadcast; by malfunction in equipment, which is source of audio. 17
Table 27. Parameters of «Audio signal level: silence» alarm Silence period 12 Time interval when audio level is below designated threshold (in seconds). Silence threshold -0.1 Audio level (in dbfs). Values from -90 to 0. Note: default parameters can be defined for any audio stream. In order to do that, select decoder from Transport stream bit rate This error reports, that bit rate of input stream is beyond of predefined range. MultiScreen server computes average bit rate and compares it with preset threshold values. Error is generated if bit rate of input stream is beyond of predefined range. Error can be caused by problems with broadband; by malfunction in equipment, which is source of audio. Table 28. Parameters of «Transport stream bit rate» alarm Bit rate enabled False Detection is ON/OFF. Bit rate period 8 Time interval for computation of average bit rate (in seconds). Threshold, high 0 Top threshold (in kbit/sec). Error is generated if it is exceeded. It is disabled if value set to 0. Threshold, low 0 Bottom threshold (in kbit/sec). Error is generated is it is not reached. It is disabled if value set to 0. Note: parameters for this alarm are being set in properties for MMS stream. By default, detection is disabled. SDI/HD-SDI and CVBS signals Signal loss This error reports missing input data during predefined time interval. Parameter «Timeout» sets the value. Error can be caused by missing data at the card input; problems with drivers installation; hardware related problem with SDI card. Note: For CVBS sources error can caused only either with derivers installation or hardware related problem with CVBS card. 18
Table 29. Parameters of «Signal loss» alarm Timeout 1000 Minimal time interval for missing input data (in milliseconds). Black video This error reports, that input stream contains black frame during designated time interval. Error can be caused by missing signal at CVBS input, malfunction in equipment, transmitting signal. Table 30. Parameters of «Black video» alarm Black 12 sec. Minimal duration of black frame, sufficient for error generation. period Black level 16 Level of brightness. Values from 0 to 255. Black threshold 0.01 Lower value corresponds to higher sensitivity of algorithm for processing of noise, present in analyzed stream. Note: default parameters can be defined for any video stream. In order to do that, select decoder from Frozen video This error reports still picture in input stream during designated time interval. Error can be caused either by static picture in input signal; by malfunction in equipment, transmitting signal. Table 31. Parameters of «Frozen video» alarm Frozen period 12 sec. Minimal duration of still picture, sufficient for error generation Frozen threshold 0.03 Lower value corresponds to higher sensitivity of algorithm for processing of noise, present in analyzed stream. Note: default parameters can be defined for any video stream. In order to do that, select decoder from Audio signal level: overload This error reports, that audio level in input stream exceeded designated threshold. Error can be caused by over amplification; by errors in decoding. Table 32. Parameters of «Audio signal level: overload» alarm Overload threshold -0.1 Allowed threshold for audio level. Values from -90 to 0 Note: default parameters can be defined for any audio stream. In order to do that, select decoder from 19
Audio signal level: silence This error reports, that audio level in input stream HAS NOT exceeded designated threshold during designated time interval. Error can be caused by silence during broadcast; by malfunction in equipment, which is source of audio. Table 33. Parameters of «Audio signal level: silence» alarm Silence period 12 Time interval when audio level is below designated threshold (in seconds). Silence threshold -0.1 Audio level (in dbfs). Values from -90 to 0. Note: default parameters can be defined for any audio stream. In order to do that, select decoder from 20