IDLvideo

IDL routines for reading and processing video files on UNIX-like operating systems

IDL is the Interactive Data Language, and is a product of Exelis Visual Information Solutions.

IDLvideo is licensed under the GPLv3.

What it does

The IDLvideo routines provide access to individual frames from video files. The DGGffVideoRead object class makes use of the native support for reading video files that was added in IDL 8.2.3. DGGgrMPlayer uses the external programs mplayer and mencoder to extract frames and pipe them into IDL. Although DGGffVideoRead is simpler and operates on all platforms, it is limited by the ffmpeg libraries that ship with IDL. DGGgrMPlayer, by contrast, can read any video format supported by mplayer, and thus is more functional.

• DGGffVideoRead__define: Extends the native IDL IDLffVideoRead object class to provide the functionality of DGGgrMPlayer.

DGGgrMPlayer uses the open-source MPlayer and MEncoder programs to open and read video files. Each frame of the video then can be transferred into IDL as an array of bytes for further processing. Because it relies on installed software rather than libraries, IDLvideo does not have to be separately compiled, and does not require any additions or modifications to IDL itself.

• DGGgrMPlayer__define: An IDL object that opens a video file, decodes it, and extracts frames.

• VOB__define: A simplified object interface for VOB files.

• mplayer: A simple resizable GUI movie player that demonstrates the capabilities of the DGGgrMPlayer object.

• mp_ripper: An IDL procedure that uses the DGGgrMPlayer object to rip a video file into individual frames that are stored on disk.

• mp_normalize: Remove overall intensity variations from a video file.

• mp_median: Computes running median of a video file.

The following utility routines are useful for working with individual images taken from video streams.

• deinterlace: Deinterlaces an image.

• rgb2luma: Convert an RGB image to grayscale.

Usage notes

IDL 8.2.X includes its own version of the FFmpeg libraries. These may limit the functionality of DGGffVideoRead, and may not be compatible with the installed versions of mplayer and mencoder on which the DGGgrMPlayer object relies. If this is a problem, follow the published instructions on Replacing the FFmpeg Version.

DGGgrMPlayer relies internally on named pipes, which also are called fifos. Fifos are available on UNIX-like systems, including MacOS, but not under Windows. Consequently, IDLVideo does not (yet) work on Windows systems. DGGffVideoRead should be truly cross-platform compatible.