Stream structures

  • NB: last update for OpenViBE 1.0.0 (mar-2015).

Introduction

All the streams are defined using EBML (Extensible Binary Meta-Language). They are all structured in 3 sections:

  • HEADER: that part is the first ever sent and received on the stream, when the user presses “play” in a scenario. It usually contains the stream description used by the boxes and algorithms to initialize everything properly (e.g. size of an internal buffer)
  • BUFFERS: the number of buffers that may then transit through the stream is unlimited. Buffers contain the payload, e.g. the current signal matrix.
  • END: that last part is received once, when the user presses “stop” in a scenario. This mechanism is not concretely used in existing boxes, however everything is implemented to handle it.

Hierarchy

The stream hierarchy is displayed on figure 1 below. Every lower stream also contains the information specific to the upper stream. The color of the corresponding input and output in the Designer are also displayed.

Fig.1 The OpenViBE stream hierarchy.

As you can see every stream is an EBML stream. Then the EBML container is specialized in 3 streams : experiment information, stimulations or streamed matrices.

The Streamed Matrix stream can be used as is, or as one of its 4 derived streams : channel localisation, channel units, feature vector, signal or spectrum.

The corresponding OpenViBE identifiers are listed below.

 #define OVTK_TypeId_EBMLStream                                   OpenViBE::CIdentifier(0x434F6587, 0x2EFD2B7E)
 #define   OVTK_TypeId_ExperimentInformation                      OpenViBE::CIdentifier(0x403488E7, 0x565D70B6)
 #define   OVTK_TypeId_Stimulations                               OpenViBE::CIdentifier(0x6F752DD0, 0x082A321E)
 #define   OVTK_TypeId_StreamedMatrix                             OpenViBE::CIdentifier(0x544A003E, 0x6DCBA5F6)
 #define     OVTK_TypeId_FeatureVector                            OpenViBE::CIdentifier(0x17341935, 0x152FF448)
 #define     OVTK_TypeId_Signal                                   OpenViBE::CIdentifier(0x5BA36127, 0x195FEAE1)
 #define     OVTK_TypeId_Spectrum                                 OpenViBE::CIdentifier(0x1F261C0A, 0x593BF6BD)
 #define     OVTK_TypeId_ChannelLocalisation                      OpenViBE::CIdentifier(0x1E4C0D6E, 0x5204EEB2)
 #define     OVTK_TypeId_ChannelUnits                             OpenViBE::CIdentifier(0x5E330216, 0x2C09724C)

The following sections will describe each stream type.

Standard EBML stream

Description

EBML stream description (November 6th 2006, version 1).

From any standard EBML stream header, you can retrieve the stream type identifier, and the stream version.

EBML description & identifiers

 * STREAM STRUCTURE
 * ----------------
 * OVTK_NodeId_Header
 *   OVTK_NodeId_Header_StreamType (integer:)
 *   OVTK_NodeId_Header_StreamVersion (integer:)
 * OVTK_NodeId_Buffer
 * OVTK_NodeId_Buffer
 * ...
 * OVTK_NodeId_End
 *


 * NODE IDENTIFIERS
 * ----------------
 #define OVTK_NodeId_Header                                           EBML::CIdentifier(0x002B395F, 0x108ADFAE)
 #define OVTK_NodeId_Header_StreamType                                EBML::CIdentifier(0x00CDD0F7, 0x46B0278D)
 #define OVTK_NodeId_Header_StreamVersion                             EBML::CIdentifier(0x006F5A08, 0x7796EBC5)
 #define OVTK_NodeId_Buffer                                           EBML::CIdentifier(0x00CF2101, 0x02375310)
 #define OVTK_NodeId_End                                              EBML::CIdentifier(0x00D9DDC3, 0x0B12873A)

Streamed matrix stream

Description

Streamed matrix stream description (November 6th 2006, version 1).

The streamed matrix stream is an EBML Stream that also contains a matrix descriptor in the header, and a matrix of float64 values in its buffers. The matrix descriptor gives the dimension count, size of each dimension, and labels of each dimension.

EBML description & identifiers

 * STREAM STRUCTURE
 * ----------------
 * OVTK_NodeId_Header
 *   OVTK_NodeId_Header_StreamType (integer:)
 *   OVTK_NodeId_Header_StreamVersion (integer:)
 *   OVTK_NodeId_Header_StreamedMatrix
 *     OVTK_NodeId_Header_StreamedMatrix_DimensionCount (integer:)
 *     OVTK_NodeId_Header_StreamedMatrix_Dimension
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Size (integer:)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:)
 *       ...
 * OVTK_NodeId_Buffer
 *   OVTK_NodeId_Buffer_StreamedMatrix
 *     OVTK_NodeId_Buffer_StreamedMatrix_RawBuffer (array of float64)
 * OVTK_NodeId_Buffer
 *   OVTK_NodeId_Buffer_StreamedMatrix
 *     OVTK_NodeId_Buffer_StreamedMatrix_RawBuffer (array of float64)
 * ...
 * OVTK_NodeId_End
 *


 * NODE IDENTIFIERS
 * ----------------
 #define OVTK_NodeId_Header_StreamedMatrix                            EBML::CIdentifier(0x0072F560, 0x7ED2CBED)
 #define OVTK_NodeId_Header_StreamedMatrix_DimensionCount             EBML::CIdentifier(0x003FEBD4, 0x2725D428)
 #define OVTK_NodeId_Header_StreamedMatrix_Dimension                  EBML::CIdentifier(0x0000E3C0, 0x3A7D5141)
 #define OVTK_NodeId_Header_StreamedMatrix_Dimension_Size             EBML::CIdentifier(0x001302F7, 0x36D8438A)
 #define OVTK_NodeId_Header_StreamedMatrix_Dimension_Label            EBML::CIdentifier(0x00153E40, 0x190227E0)
 #define OVTK_NodeId_Buffer_StreamedMatrix                            EBML::CIdentifier(0x00120663, 0x08FBC165)
 #define OVTK_NodeId_Buffer_StreamedMatrix_RawBuffer                  EBML::CIdentifier(0x00B18C10, 0x427D098C)

Channel localisation stream

Description

Channel localisation description (nov 04th 2008, version 1)

The channel localisation stream is a stream matrix stream with some constraints:

  • 2 dimensions : channels and positions
  • First dimension has variable size (channel count)
  • Second dimension has a size of 3 : the normalized cartesian coordinates in the following frame of reference : X right, Y front and Z up.

Its header also exposes a boolean value : Dynamic. If false the coordinates are assumed to be static, thus sent once and for all (e.g. with an EEG system). If Dynamic is set, the coordinates of the sensors may change over time, thus several buffer can be received over time.

EBML description & identifiers

 * STREAM STRUCTURE
 * ----------------
 * OVTK_NodeId_Header
 *   OVTK_NodeId_Header_StreamType (integer:)
 *   OVTK_NodeId_Header_StreamVersion (integer:2)
 *   OVTK_NodeId_Header_ChannelLocalisation
 *     OVTK_NodeId_Header_ChannelLocalisation_Dynamic (boolean)
 *   OVTK_NodeId_Header_StreamedMatrix
 *     OVTK_NodeId_Header_StreamedMatrix_DimensionCount (integer:2)
 *     OVTK_NodeId_Header_StreamedMatrix_Dimension
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Size (integer:channel count)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:channel 1 name)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:channel 2 name)
 *       ...
 *     OVTK_NodeId_Header_StreamedMatrix_Dimension
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Size (integer:3)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:x)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:y)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:z)
 * OVTK_NodeId_Buffer
 *   OVTK_NodeId_Buffer_StreamedMatrix
 *     OVTK_NodeId_Buffer_StreamedMatrix_RawBuffer (array of float64)
 * OVTK_NodeId_Buffer
 *   OVTK_NodeId_Buffer_StreamedMatrix
 *     OVTK_NodeId_Buffer_StreamedMatrix_RawBuffer (array of float64)
 * ...
 * OVTK_NodeId_End
 *


 * NODE IDENTIFIERS
 * ----------------
 #define OVTK_NodeId_Header_ChannelLocalisation                       EBML::CIdentifier(0xF2CFE60B, 0xEFD63E3B)
 #define OVTK_NodeId_Header_ChannelLocalisation_Dynamic               EBML::CIdentifier(0x5338AF5C, 0x07C469C3)

Channel units stream

Description

Channel units description (mar 30th 2015, version 1).

The channel units stream is a streamed matrix stream intended to carry channel measurement unit information from the drivers to Designer (e.g. ‘channel 1 is in microvolts’). The stream has some constraints:

  • 2 dimensions : channels and their properties
  • First dimension has variable size (channel count)
  • Second dimension has a size of 2 : the unit and the scaling factor.

Although the stream contents can be handled as a matrix, the unit codes and scaling factors supported and understood by OpenViBE are limited to a specific set. The list is in in toolkit/include/ovtk_defines.h.

Its header also exposes a boolean value : Dynamic. If false the units are assumed to be static, thus sent once and for all (e.g. with an EEG system). If Dynamic is set, the units may change over time, thus several buffer can be received over time. However, no component in 1.0.0 supports the dynamic units.

EBML description & identifiers

 * STREAM STRUCTURE
 * ----------------
 * OVTK_NodeId_Header
 *   OVTK_NodeId_Header_StreamType (integer:)
 *   OVTK_NodeId_Header_StreamVersion (integer:2)
 *   OVTK_NodeId_Header_ChannelUnits
 *     OVTK_NodeId_Header_ChannelUnits_Dynamic (boolean)
 *   OVTK_NodeId_Header_StreamedMatrix
 *     OVTK_NodeId_Header_StreamedMatrix_DimensionCount (integer:2)
 *     OVTK_NodeId_Header_StreamedMatrix_Dimension
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Size (integer:channel count)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:channel 1 name)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:channel 2 name)
 *       ...
 *     OVTK_NodeId_Header_StreamedMatrix_Dimension
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Size (integer:2)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:unit)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:factor)
 * OVTK_NodeId_Buffer
 *   OVTK_NodeId_Buffer_StreamedMatrix
 *     OVTK_NodeId_Buffer_StreamedMatrix_RawBuffer (array of float64)
 * OVTK_NodeId_Buffer
 *   OVTK_NodeId_Buffer_StreamedMatrix
 *     OVTK_NodeId_Buffer_StreamedMatrix_RawBuffer (array of float64)
 * ...
 * OVTK_NodeId_End
 *


 * NODE IDENTIFIERS
 * ----------------
 #define OVTK_NodeId_Header_ChannelUnits                       EBML::CIdentifier(0x17400C76, 0x16CF14C8)
 #define OVTK_NodeId_Header_ChannelUnits_Dynamic               EBML::CIdentifier(0x7307023C, 0x7F754D2E)

Feature vector stream

Description

Feature vector stream description (may 24th 2007, version 1).

The feature vector stream is a stream matrix stream with some constraints:

  •  1 dimension : the features
  • Number of features may vary, but remains the same for one stream life time.

EBML description & identifiers

 * STREAM STRUCTURE
 * ----------------
 * OVTK_NodeId_Header
 *   OVTK_NodeId_Header_StreamType (integer:)
 *   OVTK_NodeId_Header_StreamVersion (integer:)
 *   OVTK_NodeId_Header_StreamedMatrix
 *     OVTK_NodeId_Header_StreamedMatrix_DimensionCount (integer:1)
 *     OVTK_NodeId_Header_StreamedMatrix_Dimension
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Size (integer:feature count)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:feature 1 name)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:feature 2 name)
 *       ...
 * OVTK_NodeId_Buffer
 *   OVTK_NodeId_Buffer_StreamedMatrix
 *     OVTK_NodeId_Buffer_StreamedMatrix_RawBuffer (array of float64)
 * OVTK_NodeId_Buffer
 *   OVTK_NodeId_Buffer_StreamedMatrix
 *     OVTK_NodeId_Buffer_StreamedMatrix_RawBuffer (array of float64)
 * ...
 * OVTK_NodeId_End
 *

Spectrum stream

Description

Spectrum stream description (june 4th 2007, version 1).

Spectrum stream description (june 4th 2007, version 1).

The spectrum stream is a stream matrix stream with some constraints:

  • 2 dimensions : channels and frequency bands
  • First dimension has variable size (channel count)
  • Second dimension has variable size (number of frequency bands)

Its header also expose the list of frequency bands used. Each band has 2 float64 attributes: start and end of the frequency range.

EBML description & identifiers

 * STREAM STRUCTURE
 * ----------------
 * OVTK_NodeId_Header
 *   OVTK_NodeId_Header_StreamType (integer:)
 *   OVTK_NodeId_Header_StreamVersion (integer:)
 *   OVTK_NodeId_Header_StreamedMatrix
 *     OVTK_NodeId_Header_StreamedMatrix_DimensionCount (integer:2)
 *     OVTK_NodeId_Header_StreamedMatrix_Dimension
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Size (integer:channel count)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:channel 1 name)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:channel 2 name)
 *       ...
 *     OVTK_NodeId_Header_StreamedMatrix_Dimension
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Size (integer:number of frequency band)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:frequency band 1 name)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:frequency band 2 name)
 *       ...
 *   OVTK_NodeId_Header_Spectrum
 *     OVTK_NodeId_Header_Spectrum_FrequencyBand
 *       OVTK_NodeId_Header_Spectrum_FrequencyBand_Start (float64)
 *       OVTK_NodeId_Header_Spectrum_FrequencyBand_Stop (float64)
 *     OVTK_NodeId_Header_Spectrum_FrequencyBand
 *       OVTK_NodeId_Header_Spectrum_FrequencyBand_Start (float64)
 *       OVTK_NodeId_Header_Spectrum_FrequencyBand_Stop (float64)
 *     ...
 * OVTK_NodeId_Buffer
 *   OVTK_NodeId_Buffer_StreamedMatrix
 *     OVTK_NodeId_Buffer_StreamedMatrix_RawBuffer (array of float64)
 * OVTK_NodeId_Buffer
 *   OVTK_NodeId_Buffer_StreamedMatrix
 *     OVTK_NodeId_Buffer_StreamedMatrix_RawBuffer (array of float64)
 * ...
 * OVTK_NodeId_End
 *


 * NODE IDENTIFIERS
 * ----------------
 #define OVTK_NodeId_Header_Spectrum                                  EBML::CIdentifier(0x00CCFA4B, 0x14F37D4D)
 #define OVTK_NodeId_Header_Spectrum_FrequencyBand                    EBML::CIdentifier(0x0010983C, 0x21F8BDE5)
 #define OVTK_NodeId_Header_Spectrum_FrequencyBand_Start              EBML::CIdentifier(0x00AA5654, 0x2403A2CB)
 #define OVTK_NodeId_Header_Spectrum_FrequencyBand_Stop               EBML::CIdentifier(0x00A44C82, 0x05BE50D5)

Signal stream

Description

Signal stream description (may 24th 2007, version 2).

The signal stream is a stream matrix stream with some constraints:

  • 2 dimensions : channels and samples
  • First dimension has variable size (channel count)
  • Second dimension has a size corresponding to the sample count per buffer.

Its header also expose an integer value : the Sampling Frequency. Sampling frequency and sample count per buffer depends on the data producer (file reader or acquisition client).

EBML description & identifiers

 * STREAM STRUCTURE
 * ----------------
 * OVTK_NodeId_Header
 *   OVTK_NodeId_Header_StreamType (integer:)
 *   OVTK_NodeId_Header_StreamVersion (integer:)
 *   OVTK_NodeId_Header_Signal
 *     OVTK_NodeId_Header_Signal_SamplingRate (integer)
 *   OVTK_NodeId_Header_StreamedMatrix
 *     OVTK_NodeId_Header_StreamedMatrix_DimensionCount (integer:2)
 *     OVTK_NodeId_Header_StreamedMatrix_Dimension
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Size (integer:channel count)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:channel 1 name)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string:channel 2 name)
 *       ...
 *     OVTK_NodeId_Header_StreamedMatrix_Dimension
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Size (integer:number of samples per buffer)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string)
 *       OVTK_NodeId_Header_StreamedMatrix_Dimension_Label (string)
 *       ...
 * OVTK_NodeId_Buffer
 *   OVTK_NodeId_Buffer_StreamedMatrix
 *     OVTK_NodeId_Buffer_StreamedMatrix_RawBuffer (array of float64)
 * OVTK_NodeId_Buffer
 *   OVTK_NodeId_Buffer_StreamedMatrix
 *     OVTK_NodeId_Buffer_StreamedMatrix_RawBuffer (array of float64)
 * ...
 * OVTK_NodeId_End
 *


 * NODE IDENTIFIERS
 * ----------------
 #define OVTK_NodeId_Header_Signal                                    EBML::CIdentifier(0x007855DE, 0x3748D375)
 #define OVTK_NodeId_Header_Signal_SamplingRate                       EBML::CIdentifier(0x00141C43, 0x0C37006B)

Stimulation stream

Description

Stimulation stream description (may 24th 2007, version 3).

The stimulation stream is an EBML stream which buffers contains stimulation sets. Each stimulation has 3 attributes:

  • Stimulation Date: a 64bit unsigned integer in 32:32 precision (first 32 bits for the seconds, last 32 bits for the divisions)
  • Stimulation Identifier as listed in the documentation page.
  • Stimulation Duration: same encoding as stimulation date. In practice, the duration is never used by boxes, thus the value is most of the time 0.

EBML description & identifiers

 * STREAM STRUCTURE
 * ----------------
 * OVTK_NodeId_Header
 *   OVTK_NodeId_Header_StreamType (integer:)
 *   OVTK_NodeId_Header_StreamVersion (integer:)
 * OVTK_NodeId_Buffer
 *   OVTK_NodeId_Buffer_Stimulation
 *     OVTK_NodeId_Buffer_Stimulation_NumberOfStimulations (integer)
 *     OVTK_NodeId_Buffer_Stimulation_Stimulation
 *       OVTK_NodeId_Buffer_Stimulation_Stimulation_Identifier (integer)
 *       OVTK_NodeId_Buffer_Stimulation_Stimulation_Date (integer)
 *       OVTK_NodeId_Buffer_Stimulation_Stimulation_Duration (integer)
 *     OVTK_NodeId_Stimulation_Stimulation
 *     ...
 * OVTK_NodeId_Buffer
 * OVTK_NodeId_Buffer
 * ...
 * OVTK_NodeId_End
 *


 * NODE IDENTIFIERS
 * ----------------
 #define OVTK_NodeId_Buffer_Stimulation                               EBML::CIdentifier(0x006DEABE, 0x7FC05A20)
 #define OVTK_NodeId_Buffer_Stimulation_NumberOfStimulations          EBML::CIdentifier(0x00BB790B, 0x2B8574D8)
 #define OVTK_NodeId_Buffer_Stimulation_Stimulation                   EBML::CIdentifier(0x0016EAC6, 0x29FBCAA1)
 #define OVTK_NodeId_Buffer_Stimulation_Stimulation_Identifier        EBML::CIdentifier(0x006FA5DB, 0x4BAC31E9)
 #define OVTK_NodeId_Buffer_Stimulation_Stimulation_Date              EBML::CIdentifier(0x00B866D8, 0x14DA5374)
 #define OVTK_NodeId_Buffer_Stimulation_Stimulation_Duration          EBML::CIdentifier(0x14EE055F, 0x87FBCC9C)

Experimentation information stream

Description

Experimentation information stream description (november 6th 2006, version 1).

The experiment information stream is an EBML stream that provides in its header some information about the experiment being conducted. These information are entered for example in the acquisition server, when configuring the driver before starting the acquisition. You can find :

  • Experiment description: identifier and date.
  • Subject description: identifier, name, age and gender.
  • Context: laboratory identifier and name, technician identifier and name.

EBML description & identifiers

 * STREAM STRUCTURE
 * ----------------
 * OVTK_NodeId_Header
 *   OVTK_NodeId_Header_StreamType (integer:)
 *   OVTK_NodeId_Header_StreamVersion (integer:)
 *   OVTK_NodeId_Header_ExperimentInformation
 *     OVTK_NodeId_Header_ExperimentInformation_Experiment
 *       OVTK_NodeId_Header_ExperimentInformation_Experiment_Identifier (integer)
 *       OVTK_NodeId_Header_ExperimentInformation_Experiment_Date (date)
 *     OVTK_NodeId_Header_ExperimentInformation_Subject
 *       OVTK_NodeId_Header_ExperimentInformation_Subject_Identifier (integer)
 *       OVTK_NodeId_Header_ExperimentInformation_Subject_Name (string)
 *       OVTK_NodeId_Header_ExperimentInformation_Subject_Age (integer)
 *       OVTK_NodeId_Header_ExperimentInformation_Subject_Gender (integer)
 *     OVTK_NodeId_Header_ExperimentInformation_Context
 *       OVTK_NodeId_Header_ExperimentInformation_Context_LaboratoryIdentifier (integer)
 *       OVTK_NodeId_Header_ExperimentInformation_Context_LaboratoryName (string)
 *       OVTK_NodeId_Header_ExperimentInformation_Context_TechnicianIdentifier (integer)
 *       OVTK_NodeId_Header_ExperimentInformation_Context_TechnicianName (string)
 * OVTK_NodeId_End
 *


* NODE IDENTIFIERS
 * ----------------
 #define OVTK_NodeId_Header_ExperimentInformation                               EBML::CIdentifier(0x00746BA0, 0x115AE04D)
 #define OVTK_NodeId_Header_ExperimentInformation_Experiment                    EBML::CIdentifier(0x0011D6B7, 0x48F1AA39)
 #define OVTK_NodeId_Header_ExperimentInformation_Experiment_Identifier         EBML::CIdentifier(0x006ACD74, 0x1C960C26)
 #define OVTK_NodeId_Header_ExperimentInformation_Experiment_Date               EBML::CIdentifier(0x002F8FB7, 0x6DA7552D)
 #define OVTK_NodeId_Header_ExperimentInformation_Subject                       EBML::CIdentifier(0x003EC620, 0x333E0A94)
 #define OVTK_NodeId_Header_ExperimentInformation_Subject_Identifier            EBML::CIdentifier(0x00D62974, 0x473D4AA5)
 #define OVTK_NodeId_Header_ExperimentInformation_Subject_Name                  EBML::CIdentifier(0x0041FD0A, 0x6BCD9A99)
 #define OVTK_NodeId_Header_ExperimentInformation_Subject_Age                   EBML::CIdentifier(0x00DF7DD9, 0x33336C51)
 /* for retro compat */
 #define OVTK_NodeId_Header_ExperimentInformation_Subject_Sex                   EBML::CIdentifier(0x0069BB84, 0x3FC8E149)
 #define OVTK_NodeId_Header_ExperimentInformation_Subject_Gender                EBML::CIdentifier(0x0069BB84, 0x3FC8E149)
 #define OVTK_NodeId_Header_ExperimentInformation_Context                       EBML::CIdentifier(0x0018C291, 0x7985DFDD)
 #define OVTK_NodeId_Header_ExperimentInformation_Context_LaboratoryIdentifier  EBML::CIdentifier(0x003F11B9, 0x26D76D9C)
 #define OVTK_NodeId_Header_ExperimentInformation_Context_LaboratoryName        EBML::CIdentifier(0x00EB1F23, 0x51C23B83)
 #define OVTK_NodeId_Header_ExperimentInformation_Context_TechnicianIdentifier  EBML::CIdentifier(0x00874A7F, 0x60DC34C2)
 #define OVTK_NodeId_Header_ExperimentInformation_Context_TechnicianName        EBML::CIdentifier(0x00C8C393, 0x31CE5B3E)

Acquisition stream

Description

Acquisition stream description (nov 2014, version 3). This is a multiplexed stream.

The acquisition stream encapsulates 5 streams : experiment information, channel localisation, channel units, signal and stimulation.

This stream is produced by the Acquisition Server and is sent to every client connected via tcp/ip network connection. The stream is received by the Acquisition Client box, that separates each streams and makes them available on 5 corresponding outputs.

EBML description & identifiers

 * STREAM STRUCTURE
 * ----------------
 * OVTK_NodeId_Header
 *   OVTK_NodeId_Acquisition_Header_ExperimentInformation
 *     ... some experiment information stream header
 *   OVTK_NodeId_Acquisition_Header_Signal
 *     ... some signal stream header
 *   OVTK_NodeId_Acquisition_Header_Stimulation
 *     ... some stimulation stream header
 *   OVTK_NodeId_Acquisition_Header_ChannelLocalisation
 *     ... some channel localisation stream header
 *   OVTK_NodeId_Acquisition_Header_ChannelUnits
 *     ... some channel units stream header
 * OVTK_NodeId_Buffer
 *   OVTK_NodeId_Acquisition_Buffer_ExperimentInformation
 *     ... some experiment information stream buffer
 *   OVTK_NodeId_Acquisition_Buffer_Signal
 *     ... some signal stream buffer
 *   OVTK_NodeId_Acquisition_Buffer_Stimulation
 *     ... some stimulation stream buffer
 *   OVTK_NodeId_Acquisition_Buffer_ChannelLocalisation
 *     ... some channel localisation stream buffer
 *   OVTK_NodeId_Acquisition_Buffer_ChannelUnits
 *     ... some channel units stream buffer
 * OVTK_NodeId_Buffer
 * OVTK_NodeId_Buffer
 * ...
 *

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