VirtualDub help - Capture: Multi-segment mode | |||
Processing: Main UI Video captureEditing Filtering Rendering/saving Artifacts The pipeline Direct mode Display panes Frameserver Video filter reference Video shader reference Hardware setup Dialogs:Driver selection Audio setup Pipeline Filtering Info panel Multi-segment mode Timing dialog Performance Troubleshooting Video filters On a crash...Video frame rate control Video color depth Video range Video compression Audio filters Audio interleaving Audio compression Audio conversion Audio volume Capture settings Preferences | Spill mode allows a video capture operation to be split across multiple files. This allows file size limits to be bypassed and also permits use of multiple partitions. Selecting spill drives for captureSelect the Capture > Capture drives to set up the drive array for spill mode:
Using multi-segment captureEnable Capture > Enable multisegment capture to allow use of spill drives. The capture filename will then be used to generate the prefix for sequentially numbered files, so that a base name of capture.avi produces capture.00.avi, capture.01.avi, capture.02.avi, etc. Then begin capture as usual to start capturing to a series of sequential files.
Caveats with multi-segment captureAs when editing, audio and video compression can impact the ability of VirtualDub to produce clean cuts between segments. In the interest of speed, VirtualDub is a bit sloppy when writing capture segments. Issues include:
If you will attempt to load individual segments or load the files into a different program, it is recommended that you use video compression that does not use delta frames, and disable audio compression. Reading multi-segment capture filesEach capture segment written by VirtualDub contains a record in it that indicates the location of the next segment. This makes it possible for VirtualDub to follow the sequence of capture files without knowing the list of spill drives, even if the sequence hops between drives. The algorithm for following the chain is as follows:
It is thus not a good idea to mix segments from different captures, as VirtualDub may get confused if it sees a capture.06.avi that is actually from a different sequence than capture.05.avi in the same location. The format of the segment hint is a chunk with the FOURCC segm within the AVI header block. It consists of a single byte which is 00 if no further segments are present, or 01 if more segments should be loaded, followed by the filename of the next segment, null terminated. (Regrettably, this is 8-bit ANSI encoded, not 16-bit Unicode.) The full filename is encoded, although only the path is used, and the filename should still follow the basename.nn.avi convention. |