Using the Video Capture Connector and Adapter

Using the Video Capture Connector

Overview

The Video Capture connector enables SAS Event Stream Processing (ESP) to stream video frames into or out of an ESP model. The connector uses third-party libraries from FFmpeg to read and decode the input, supporting publish and subscribe operations. As a publisher, the Video Capture connector reads video from an external source and publishes each extracted image frame into a Source window as a unique event that contains a binary blob field.

As a subscriber, the Video Capture connector subscribes to a window and reads output events that contain image data. The output can represent a real-time streaming protocol (RTSP) stream, a video file, or another stream type that is supported by FFmpeg.

The following parameters enable you to set values in the AVOption data structure. FFmpeg uses this data structure to set parameters that control audio-video codecs, formats, and filters.

inputformat
avoptions

The AVOption data structure enables you to customize the behavior of FFmpeg during encoding, decoding, and processing of multimedia streams. For more information about the parameters that you can set, see FFmpeg documentation.

Source Window Schema Requirements

The Source window schema must contain at least two fields: a key field of type int64 for a unique ID and one of type blob for a video frame. The video frame is encoded in JPEG format, TIFF format, SAS wide format (uncompressed), or PNG format.

<schema>
   <fields>
      <field name="ID" type="int64" key="true"/>
      <field name="image" type="blob"/>
   </fields>
</schema>

<schema>
   <fields>
      <field name="ID" type="int64" key="true"/>
      <field name="image" type="blob"/>
   </fields>
</schema>

In addition to these required fields, the Source window schema can contain a third field of type stamp. When specified, this field contains the time that the frame is received.

<schema>
   <fields>
      <field name="ID" type="int64" key="true"/>
      <field name="image" type="blob"/>
      <field name="image_time" type="stamp"/>
   </fields>
</schema>

<schema>
   <fields>
      <field name="ID" type="int64" key="true"/>
      <field name="image" type="blob"/>
      <field name="image_time" type="stamp"/>
   </fields>
</schema>

The schema can contain a different third field of type string that, when specified, contains the string configured in the cameraid configuration parameter.

<schema>
   <fields>
      <field name="ID" type="int64" key="true"/>
      <field name="image" type="blob"/>
      <field name="cameraid" type="string"/>
   </fields>
</schema>

<schema>
   <fields>
      <field name="ID" type="int64" key="true"/>
      <field name="image" type="blob"/>
      <field name="cameraid" type="string"/>
   </fields>
</schema>

The schema can contain both the time that the frame is received and the string configured in the cameraid configuration parameter. When both are specified, the time must precede the cameraid.

<schema>
   <fields>
      <field name="ID" type="int64" key="true"/>
      <field name="image" type="blob"/>
      <field name="image_time" type="stamp"/>
      <field name="cameraid" type="string"/>
   </fields>
</schema>

<schema>
   <fields>
      <field name="ID" type="int64" key="true"/>
      <field name="image" type="blob"/>
      <field name="image_time" type="stamp"/>
      <field name="cameraid" type="string"/>
   </fields>
</schema>

If the schema contains both the time that the frame is received and the string configured in the cameraid configuration parameter, it can contain an additional field of type string or rstring. When specified, this field contains a JSON string containing metadata coming from FFmpeg related to the input stream and frame.

<schema>
   <fields>
      <field name="ID" type="int64" key="true"/>
      <field name="image" type="blob"/>
      <field name="image_time" type="stamp"/>
      <field name="cameraid" type="string"/>
      <field name="metadata" type="string"/>
   </fields>
</schema>

<schema>
   <fields>
      <field name="ID" type="int64" key="true"/>
      <field name="image" type="blob"/>
      <field name="image_time" type="stamp"/>
      <field name="cameraid" type="string"/>
      <field name="metadata" type="string"/>
   </fields>
</schema>

Subscriber Usage

Required Parameters for Subscriber Video Capture Connector
Parameter	Description
`filename`	Specifies the output file name or stream name.
`outputformat`	Specifies the output format. Supported formats include `rtsp`, `mpeg`, `mp4`, and `hls`. For more information, see FFmpeg formats.
`imagefieldname`	Specifies the field from the output event that contains the image to output.

Optional Parameters for Subscriber Video Capture Connector
Parameter	Description
`outputtimebase`	Specifies the denominator of the time base for the output.
`outputcodec`	Specifies the output codec. The default value depends on `outputformat`.
`bitrate`	Specifies the output bit rate in megabits per second. The default value is `4`.
`avoptions`	Specifies any additional FFmpeg AVoption as a comma-separated list (for example, `"pixel_format="mjpeg",video_size="640x480",timeout=10000000"`). Note: String values must be enclosed in double quotation marks.
`resize_x`	Specifies the horizontal size of published images. The default value is the original size.
`resize_y`	Specifies the vertical size of published images. The default value is the original size.
`cameraidfieldname`	Specifies the subscribed window field that contains the value to compare to the ID that is configured in `cameraid`. If the values do not match, the frame is suppressed. By default, no frames are suppressed. This parameter is not allowed unless `cameraid` is also configured.
`cameraid`	Specifies the camera ID to compare to the value in the event field that is specified by `cameraidfieldname`. If the values do not match, the frame is suppressed. By default, no frames are suppressed. This parameter is not allowed unless `cameraidfieldname` is also configured.
`maxreconnectretries`	Specifies the number of times the connector attempts to reconnect. A value of `-1` enables unlimited retries. The default value is `0`, which disables retries. This parameter applies only to streaming input or output (for example, real-time streaming protocol) and is ignored when the input or output is a file.
`reconnectdelay`	Specifies the delay between retry attempts in milliseconds. When the value is `0` or less, the delay increases incrementally from `0` seconds up to a maximum of `256` seconds. The default value is `0`. When the connector runs in subscriber mode, events that are generated between retries are discarded.
`gopsize`	Specifies the group of pictures (GOP) value as an integer. The default value is `12`.
`filters`	Specifies the FFmpeg filters to apply to received frames as a string. Valid filters include `crop`, `rotate`, `vflip`, `hflip`, and `scale`. Multiple filters can be used together in a single line as a FFmpeg filtergraph (for example, `<property name="filters"><![CDATA[rotate=90*PI/180 , hflip]]></property>`). You can reference incoming event field values in a filtergraph by using the FFmpeg metadata definition with the key `esp.event.<fieldname>`. For example, `%{metadata\:esp.event.camera_id}` is replaced with the value of `camera_id` for the corresponding event or frame. For more information, see FFmpeg documentation. Note: If you specify the `resize_x` and `resize_y` parameters, the connector applies resizing after the filtergraph runs. To resize frames before or within the filtergraph, use the `scale` filter. For more information, see Filtergraph documentation.
`restartonerror`	Specifies whether to restart the connector when it stops due to an error. The connector restarts only if the error occurs after the connector reaches the running state.

Publisher Usage

Required Parameters for Publisher Video Capture Connector
Parameter	Description
`type`	Specifies publisher connector. The value must be set to `pub`.
`filename`	Specifies a real-time streaming protocol URL to read a stream from or the file system path to read a file from (for example, `rtsp://167.21.72.35:554/live/NCAM065.stream` or `/devs/videoStream/small_bunny_1080p_60fps.mp4`).
`publishformat`	Specifies the output format of published images. Valid values include `jpeg`, `wide`, `tiff`, and `png`.

Optional Parameters for Publisher Video Capture Connector
Parameter	Description
`transactional`	Sets the event block type to transactional. The default event block type is `normal`.
`blocksize`	Specifies the number of events to include in a published event block. Specify an integer value. The default value is `1`.
`configfilesection`	Specifies the name of the section in /opt/sas/viya/config/etc/SASEventStreamProcessingEngine/default/connectors.config to parse for configuration parameters. Specify the value as `[configfilesection]`.
`publishwithupsert`	Specifies to build events with `opcode = Upsert` instead of `opcode = Insert`.
`inputrate`	Specifies the input video frame rate. The default value is the rate that is extracted from the input stream.
`publishrate`	Specifies the publish rate in frames per second. Specify `0` to match the input video frame rate or `-1` to publish at the maximum rate. The default value is `0`.
`publishcolor`	Specifies the order of color layers for published images. Valid values are `bgr` (default) and `rgb`.
`resize_x`	Specifies the horizontal size of published images. The default value is the original size.
`resize_y`	Specifies the vertical size of published images. The default value is the original size.
`qscale`	Specifies the desired image quality for `jpeg` or `tiff`. Valid values are integers from `1` to `31`, with `1` specifying the highest quality and largest file size and `31` specifying the lowest. The normal range for `jpeg` is `2` through `31`. The default value is `3`.
`repeatcount`	Specifies the number of times to repeat reading and processing the file received from the path specified by the `filename` parameter. The default value is `0`.
`inputformat`	Specifies the value of the FFmpeg AVoption parameter `input_format`, which sets the preferred pixel format (for raw video) or codec name.
`avoptions`	Specifies any additional FFmpeg AVoption as a comma separated list (for example, `"pixel_format="mjpeg",video_size="640x480",timeout=10000000"`). Note: String values must be enclosed in double quotation marks.
`cameraid`	Specifies an arbitrary string that is copied into the corresponding string field in the Source window. This value can be used by the model to identify the source camera.
`extendedframeinfo`	Specifies whether to include additional metadata in the source window field containing the FFmpeg metadata. This value is ignored if that field is not present in the source window schema.
`maxreconnectretries`	Specifies the number of times the connector attempts to reconnect. A value of `-1` enables unlimited retries. The default value is `0`, which disables retries.This parameter applies only to streaming input or output (for example, real-time streaming protocol) and is ignored when the input or output is a file.
`reconnectdelay`	Specifies the delay between retry attempts in milliseconds. When the value is `0` or less, the delay increases incrementally from `0` seconds up to a maximum of `256` seconds. The default value is `0`. When the connector runs in subscriber mode, the events that are generated between retries are discarded.
`filters`	Specifies the FFmpeg filters to apply to received frames as a string. Valid values include `crop`, `rotate`, `vflip`, `hflip`, and `scale`. Multiple filters can be used together in a single line as a FFmpeg filtergraph (for example, `<property name="filters"><![CDATA[rotate=90*PI/180 , hflip]]></property>`). For more information, see FFmpeg documentation. Note: If you specify the `resize_x` and `resize_y` parameters, the connector applies resizing after the filtergraph runs. To resize frames before or within the filtergraph, use the `scale` filter. For more information, see Filtergraph documentation.
`restartonerror`	Specifies whether to restart the connector when it stops due to an error. The connector restarts only if the error occurs after the connector reaches the running state.
`frameratemethod`	Specifies the method that is used for sampling the published events. This parameter is effective only for stream-type input, such as RTSP streams. Valid values include `last`, `pts`, or `closest`. When `last`, the connector publishes the latest frame before the tick time. When `pts`, the connector calculates the frame presentation time stamp (PTS) interval based on the publish period and publishes the first image with a PTS greater than or equal to the calculated PTS. When `closest`, the connector publishes the closest frame to the tick time. The default value is `closest`.

Using the Video Capture Adapter

Overview

The Video Capture adapter reads input video streams and extracts each image frame. Components that use the adapter can process the frame as a binary blob field. The adapter uses third-party libraries from FFmpeg to read and decode the input, supporting publish and subscribe operations. The information in Source Window Schema Requirements also applies to the Video Capture adapter.

As a publisher, the Video Capture adapter reads video from an external source and publishes each extracted image frame into a Source window as a unique event that contains a binary blob field. As a subscriber, the Video Capture adapter subscribes to a window and reads output events that contain image data. The output can represent a real-time streaming protocol (RTSP) stream, a video file, or another stream type that is supported by FFmpeg.

The following parameters enable you to set values in the AVOption data structure. FFmpeg uses this data structure to set parameters that control audio-video codecs, formats, and filters.

inputformat
avoptions

The AVOption data structure enables you to customize the behavior of FFmpeg during encoding, decoding, and processing of multimedia streams. For more information, see FFmpeg documentation.

Subscriber Usage

Required Parameters for Subscriber Video Capture Adapter
Parameter	Description
`type=sub`	Specifies a subscriber adapter.
`url=pubsubURL`	Specifies the standard URL in the form dfESP://host :pubsubport/ project/continuousquery /window. Users append the following strings for subscribers:`?snapshot=false`. When `?snapshot=true`, the subscriber receives a collection of Insert events that are contained in the window at that point in time. The subscriber then receives a stream of events produced from the time of the snapshot onward. Those subsequent events can be Inserts, Updates, or Deletes. Note: `?snapshot=true` is invalid. Users append `?collapse=true \| false` or `?rmretdel=true \| false` for subscribers if needed.
`filename=url`	Specifies the real-time streaming protocol URL to write the stream to or specifies the path to write an output file to (for example, `rtsp://167.21.72.35:554/live/NCAM065.stream` or `/devs/videoStream/small_bunny_1080p_60fps.mp4`).
`imagefieldname=field`	Specifies the subscribed window field that contains the image data.

Optional Parameters for Subscriber Video Capture Adapter
Parameter	Description
`restartonerror= true \| false`	When `true`, specifies to restart the adapter if a fatal error is reported.
`transportconfigfile=file`	Specifies the publish/subscribe transport configuration file. For `rabbitmq`, the default is ./rabbitmq.cfg. For `kafka`, the default is ./kafka.cfg. Note: No transport configuration file is required for native transport.
`cameraid=id`	Specifies the camera ID to compare to the value in the event field that is specified by `cameraidfieldname`. If the values do not match, the frame is suppressed. By default, no frames are suppressed. This parameter is not allowed unless `cameraidfieldname` is also configured.
`cameraidfieldname=field`	Specifies the subscribed window field that contains the value to compare to the ID that is configured in `cameraid`. If the values do not match, the frame is suppressed. By default, no frames are suppressed. This parameter is not allowed unless `cameraid` is also configured.
`resize_x=size`	Specifies the horizontal size of produced images. The default value is the original size.
`resize_y=size`	Specifies the vertical size of produced images. The default value is the original size.
`avoptions=options`	Specifies any additional FFmpeg AVoption as a comma-separated list (for example, `"pixel_format="mjpeg",video_size="640x480",timeout=10000000"`). Note: String values must be enclosed in double quotation marks.
`maxreconnectretries=number`	Specifies the number of times the connector attempts to reconnect. A value of `-1` enables unlimited retries. The default value is `0`, which disables retries. This parameter applies only to streaming input or output (for example, real-time streaming protocol) and is ignored when the input or output is a file.
`reconnectdelay=milliseconds`	Specifies the delay between retry attempts in milliseconds. When the value is `0` or less, the delay increases incrementally from `0` seconds up to a maximum of `256` seconds. The default value is `0`. When the connector runs in subscriber mode, the events that are generated between retries are discarded.
`outputtimebase=time base`	Specifies the time base of the output stream. The default value is `30`.
`outputformat=format`	Specifies the output format. Supported formats include `rtsp`, `mpeg`, `mp4`, and `hls`. For more information, see FFmpeg formats.
`bitrate=mbps`	Specifies the bit rate of the output stream. The default value is `4`.
`gopsize=integer`	Specifies the group of pictures (GOP) value. The default value is `12`.
`outputcodec=codec`	Specifies the output codec. The default value depends on `outputformat`.
`filters=<value>`	Specifies the FFmpeg filters to apply to received frames as a string. Valid filters include `crop`, `rotate`, `vflip`, `hflip`, and `scale`. Multiple filters can be used together in a single line as a FFmpeg filtergraph (for example, `<property name="filters"><![CDATA[rotate=90*PI/180 , hflip]]></property>`). You can reference incoming event field values in a filtergraph by using the FFmpeg metadata definition with the key `esp.event.<fieldname>`. For example, `%{metadata\:esp.event.camera_id}` is replaced with the value of `camera_id` for the corresponding event or frame. For more information, see FFmpeg documentation. Note: If you specify the `resize_x` and `resize_y` parameters, the connector applies resizing after the filtergraph runs. To resize frames before or within the filtergraph, use the `scale` filter. For more information, see Filtergraph documentation.

Publisher Usage

Required Keys
Key-Value Pair	Description
`url= pubsubURL`	Specifies the standard URL in the form dfESP://host:pubsubport/ project/continuousquery /window.
`filename= name`	Specifies a real-time streaming protocol URL to read a stream from or specifies the file system path to read a file from (for example, `rtsp://167.21.72.35:554/live/NCAM065.stream` or `/devs/videoStream/small_bunny_1080p_60fps.mp4`).
`publishformat= jpeg \| wide \| tiff \| png`	Specifies the output format of published images.

Optional Keys
Key-Value Pair	Description
`gdconfig= file`	Specifies the guaranteed delivery configuration file.
`transport=native \| rabbitmq \| kafka`	Specifies the transport type. If you specify `rabbitmq` or `kafka` transports instead of the default `native` transport, then use the required client configuration files that are specified in the description of the C++ `C_dfESPpubsubSetPubsubLib()` API call.
`loglevel=trace \| debug \| info \| warn \| error \| fatal \| off`	Sets the logging level for the adapter. This is the same range of logging levels that you can set in the `C_dfESPpubsubInit()` publish/subscribe API call and in the engine `initialize()` call. The default level is `warn`.
`logconfigfile= file`	Specifies the log configuration file.
`tokenlocation= location`	Specifies the location of the file in the local file system that contains the OAuth token that is required for authentication by the publish/subscribe server.
`configfilesection=[ section]`	Specifies the name of the section in /opt/sas/viya/config/etc/SASEventStreamProcessingEngine/default/connectors.config to parse for configuration parameters. Specify the value as `[configfilesection]`..
`blocksize= size`	Sets the block size. The default value is `1`.
`transactional=true \| false`	When `true`, event blocks are transactional. By default, event blocks are normal.
`publishwithupsert=true \| false`	When `true`, build events with `opcode = Upsert` instead of `Insert`.
`restartonerror=true \| false`	When `true`, specifies to restart the adapter if a fatal error is reported.
`transportconfigfile= file`	Specifies the publish/subscribe transport configuration file. For `rabbitmq`, the default is ./rabbitmq.cfg. For `kafka`, the default is ./kafka.cfg. Note: No transport configuration file is required for native transport.
`quiesceproject=true \| false`	When `true`, quiesces the project after all events are injected into the Source window.
`inputrate=rate`	Specifies the input video frame rate. The default value is the rate that is extracted from the input stream.
`publishrate=rate`	Specifies the publish rate in frames per second. Specify `0` to match the input video frame rate or `-1` to publish at the maximum rate. The default value is `0`.
`publishcolor= bgr \| rgb`	Specifies the order of color layers for published images. Valid values are `bgr` (default) and `rgb`.
`resize_x=size`	Specifies the horizontal size of published images. The default value is the original size.
`resize_y=size`	Specifies the vertical size of published images. The default value is the original size.
`qscale=scale`	Specifies the desired image quality for `jpeg` or `tiff`. Valid values are integers from `1` to `31`, with `1` specifying the highest quality and largest file size and `31` specifying the lowest. The normal range for `jpeg` is `2` through `31`. The default value is `3`.
`repeatcount=count`	Specifies the number of times to repeat reading and processing the file received from the path specified by the `filename` parameter. The default value is `0`.
`inputformat=format`	Specifies the value of the FFmpeg AVoption parameter `input_format`, which sets the preferred pixel format (for raw video) or codec name.
`avoptions=options`	Specifies any additional FFmpeg AVoption as a comma-separated list (for example, `"pixel_format="mjpeg",video_size="640x480",timeout=10000000"`). Note: String values must be enclosed in double quotation marks.
`cameraid=id`	Specifies an arbitrary string that is copied into the corresponding string field in the Source window. This value can be used by the model to identify the source camera.
`extendedframeinfo=true \| false`	When `true`, specifies to include additional metadata in the source window field containing the FFmpeg metadata. This value is ignored if that field is not present in the source window schema.
`maxreconnectretries=number`	Specifies the number of times the connector attempts to reconnect. A value of `-1` enables unlimited retries. The default value is `0`, which disables retries.This parameter applies only to streaming input or output (for example, real-time streaming protocol) and is ignored when the input or output is a file.
`reconnectdelay=milliseconds`	Specifies the delay between retry attempts. When the value is `0` or less, the delay increases incrementally from `0` seconds up to a maximum of `256` seconds. The default value is `0`. When the connector runs in subscriber mode, the events that are generated between retries are discarded.
`filters=crop \| rotate \| vflip \| hflip \| scale`	Specifies the FFmpeg filters to apply to received frames as a string. Multiple filters can be used together in a single line as a FFmpeg filtergraph (for example, `<property name="filters"><![CDATA[rotate=90*PI/180 , hflip]]></property>`). For more information, see FFmpeg documentation. Note: If you specify the `resize_x` and `resize_y` parameters, the connector applies resizing after the filtergraph runs. To resize frames before or within the filtergraph, use the `scale` filter. For more information, see Filtergraph documentation.

Output Examples

Here is an example of an RTSP stream output:

<connector class="videocap" name="video_out" active="true">
<properties>
<property name="type"><![CDATA[sub]]></property>
<property name="snapshot"><![CDATA[false]]></property>
<property name="outputtimebase"><![CDATA[30]]></property>
<property name="imagefieldname"><![CDATA[image]]></property>
<property name="filename"><![CDATA[rtsp://127.0.0.1:8554/stream]]></property>
<property name="outputformat"><![CDATA[rtsp]]></property>
</properties>
</connector>

<connector class="videocap" name="video_out" active="true">
<properties>
<property name="type"><![CDATA[sub]]></property>
<property name="snapshot"><![CDATA[false]]></property>
<property name="outputtimebase"><![CDATA[30]]></property>
<property name="imagefieldname"><![CDATA[image]]></property>
<property name="filename"><![CDATA[rtsp://127.0.0.1:8554/stream]]></property>
<property name="outputformat"><![CDATA[rtsp]]></property>
</properties>
</connector>

Here is an example of an MP4 file output:

<connector class="videocap" name="video_out" active="true">
<properties>
<property name="type"><![CDATA[sub]]></property>
<property name="snapshot"><![CDATA[false]]></property>
<property name="outputtimebase"><![CDATA[30]]></property>
<property name="imagefieldname"><![CDATA[image]]></property>
<property name="filename"><![CDATA[output/file.mp4]]></property>
<property name="outputformat"><![CDATA[mp4]]></property>
<property name="outputcodec"><![CDATA[h264]]></property>
<property name="bitrate"><![CDATA[4.5]]></property>
</properties>
</connector>

<connector class="videocap" name="video_out" active="true">
<properties>
<property name="type"><![CDATA[sub]]></property>
<property name="snapshot"><![CDATA[false]]></property>
<property name="outputtimebase"><![CDATA[30]]></property>
<property name="imagefieldname"><![CDATA[image]]></property>
<property name="filename"><![CDATA[output/file.mp4]]></property>
<property name="outputformat"><![CDATA[mp4]]></property>
<property name="outputcodec"><![CDATA[h264]]></property>
<property name="bitrate"><![CDATA[4.5]]></property>
</properties>
</connector>

Here is an example of an HLS output:

<connector class="videocap" name="video_out" active="true">
<properties>
<property name="type"><![CDATA[sub]]></property>
<property name="snapshot"><![CDATA[false]]></property>
<property name="outputtimebase"><![CDATA[30]]></property>
<property name="imagefieldname"><![CDATA[image]]></property>
<property name="filename"><![CDATA[output/stream.m3u8]]></property>
<property name="outputformat"><![CDATA[hls]]></property>
<property name="avoptions"><![CDATA[timeout=2000,strftime=1,hls_init_time=5,hls_time=5,hls_list_size=5,hls_flags="+split_by_time+round_durations",hls_segment_filename="output/clip_%Y%m%d_%H%M%S.ts"]]></property>
</properties>
</connector>

<connector class="videocap" name="video_out" active="true">
<properties>
<property name="type"><![CDATA[sub]]></property>
<property name="snapshot"><![CDATA[false]]></property>
<property name="outputtimebase"><![CDATA[30]]></property>
<property name="imagefieldname"><![CDATA[image]]></property>
<property name="filename"><![CDATA[output/stream.m3u8]]></property>
<property name="outputformat"><![CDATA[hls]]></property>
<property name="avoptions"><![CDATA[timeout=2000,strftime=1,hls_init_time=5,hls_time=5,hls_list_size=5,hls_flags="+split_by_time+round_durations",hls_segment_filename="output/clip_%Y%m%d_%H%M%S.ts"]]></property>
</properties>
</connector>

Here is an example of a JPEG output:

<connector class="videocap" name="sub_alert_image">
<properties>
<property name="type"><![CDATA[sub]]></property>
<property name="cameraid"><![CDATA[pub_video_1]]></property>
<property name="cameraidfieldname"><![CDATA[camera_id]]></property>
        <property name="outputformat"><![CDATA[image2]]></property>
<property name="bitrate"><![CDATA[4]]></property>
<property name="outputcodec"><![CDATA[mjpeg]]></property>
<property name="snapshot"><![CDATA[false]]></property>
<property name="imagefieldname"><![CDATA[image]]></property>
<property name="filename"><![CDATA[@ESP_PROJECT_OUTPUT@/alert_%06d.jpg]]></property>
</properties>
</connector>

<connector class="videocap" name="sub_alert_image">
<properties>
<property name="type"><![CDATA[sub]]></property>
<property name="cameraid"><![CDATA[pub_video_1]]></property>
<property name="cameraidfieldname"><![CDATA[camera_id]]></property>
        <property name="outputformat"><![CDATA[image2]]></property>
<property name="bitrate"><![CDATA[4]]></property>
<property name="outputcodec"><![CDATA[mjpeg]]></property>
<property name="snapshot"><![CDATA[false]]></property>
<property name="imagefieldname"><![CDATA[image]]></property>
<property name="filename"><![CDATA[@ESP_PROJECT_OUTPUT@/alert_%06d.jpg]]></property>
</properties>
</connector>

Last updated: October 9, 2026