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The following 6 methods are used for export:

1. ListSessions - − is used to get a list of all export operations.
2. StartSession - − to start a new export operation.
3. GetSessionState - − to get the status of a specific operation.
4. StopSession - − to stop the operation.
5. DestroySession - − to delete the operation along with the export results.
6. DownloadFile - − to download the export results.

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The export operation starts on the node where the camera is located. If the export is started for several cameras, then the first node is used. Note that it is not necessary to connect to each node - − the tasks will be forwarded to them automatically.

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message Options
{
    oneof mode
    {
        LiveMode live = 1;
        ArchiveMode archive = 2;
    }
    oneof output_type
    {
        SnapshotType snapshot = 3;
        StreamType stream = 4;
    }
    repeated CommonSetting settings = 5;
    // Maximum size of output file.
    // New file will be created on reaching this value.
    uint64 max_file_size = 6;
    string export_agent_access_point = 100;
}

where,

• oneof - − implies the selection of one property that can be set in this operation.
• export_agent_access_point - − export agent id.

Using the combination of mode and output_type, you can create 4 export types:

1. LiveMode + SnapshotType - − export a frame from live video.
2. LiveMode + StreamType - − export a video clip from live video.
3. ArchiveMode + SnapshotType - − export a frame from archive.
4. ArchiveMode + StreamType - − export a video clip from archive.

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For each export type, there are timeouts after which the operation is stopped if the GetSessionState method was not executed.

The timeout is counted from the moment the export operation was started and/or from the moment the GetSessionState method was last executed.

The timeout for exporting for exporting a video clip from live video is 5 minutes, for all other export types - − 30 minutes.

The id of the export operation will be received as the response to this method.

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1. id of the export operation and its properties.

2. export status.

   Code Block
   enum EState { S_NONE = 0; S_RUNNING = 1; S_COMPLETED = 2; S_REMOVED = 3; }

   where the S_COMPLETED status does not guarantee that the export was successful.

3. If there are export operation results, then a Result message will be received.
   

   Code Block
   message Result { message File { string path = 1; uint64 size = 2; string min_timestamp = 3; string max_timestamp = 4; string mime_type = 5; } repeated File files = 1; bool succeeded = 2; }

   where,

   1. succeeded - − indicates that the export was successful;

   2. message File - − describes the list of files ready for download, including the conditional path to be used in the DownloadFile method and size.

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1. export operation id;
2. path to the file;
3. chunk_size_kb - − data block size;
4. start_from_chunk_index - − serial number of the data block.

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