GstDiskSrc
Asynchronous read from a file (disksrc)
Asynchonously read buffers from a file.
GST_DISKSRC_OPEN
the disksrc is open for reading
@GST_DISKSRC_OPEN:
@GST_DISKSRC_FLAG_LAST:
Specify the location of the file to read.
Specify how many bytes to read at a time.
Get/set the current offset in the file.