Video and Audio Chunk Granularity

The chunk granularity is a logical block size for an AVI file that is used for writing and retrieving audio and video data chunks. When writing audio and video chunks to disk, AVICap adds filler chunks (RIFF  JUNK  chunks) as necessary to fill each logical block of data.

You can retrieve the current chunk granularity setting by using the WM_CAP_GET_SEQUENCE_SETUP1GNHJI message (or the capCaptureGetSetup1A5QZ0N macro). The current chunk granularity is stored in the wChunkGranularity member of the CAPTUREPARMSRYJ.8W structure. You can specify a new chunk granularity as the value of wChunkGranularity and then send the updated CAPTUREPARMS structure to the capture window by using the WM_CAP_SET_SEQUENCE_SETUPYGBQ.R message (or the capCaptureSetSetup115V26W macro). You can also specify zero for this member to set the chunk granularity to the sector size of the disk.