# DSHeaderChunk

Stream header structure.

### Synopsis

    typedef struct DSHeaderChunk {
       SUBS_CHUNK_COMMON
       long headerVersion;
       long streamBlockSize;
       long streamBuffers;
       long streamerDeltaPri;
       long dataAcqDeltaPri;
       long numSubsMsgs;
       long audioClockChan;
       long enableAudioChan;
       long preloadInstList[DS_HDR_MAX_PRELOADINST];
       DSHeaderSubs   subscriberList[DS_HDR_MAX_SUBSCRIBER];
    } DSHeaderChunk,  *DSHeaderChunkPtr;

### Description

The basic data buffer structure managed by the stream parser. Each buffer is obtained from the stream's data acquisition component. The first part of every physical data buffer must contain the header information described by this structure. The actual data component of a `DSDataBuf` can be a different length for each stream. However, buffer sizes are fixed within a given stream.

### Fields

`SUBS_CHUNK_COMMON`
  From SubscriberUtils.h

`headerVersion`
  Version of header data.

`streamBlockSize`
  Size of stream buffers in this stream.

`streamBuffers`
  Suggested number of stream buffers to use.

`streamerDeltaPri`
  Delta priority for streamer thread.

`dataAcqDeltaPri`
  Delta priority for data acquisition thread.

`numSubsMsgs`
  Number of subscriber messages to allocate.

`audioClockChan`
  Logical channel number of audio clock channel.

`enableAudioChan`
  Mask of audio channels to enable.

`preloadInstList[DS_HDR_MAX_PRELOADINST]`

`subscriberList[DS_HDR_MAX_SUBSCRIBER]`

### Associated Files

DSStreamHeader.h