The implementation of Range header support in the RTSP server module of VLC is relatively incomplete. At this point in time the code expects the parameter to the Range header to be a float only - There is at this stage no support for the specific time references or the "now" keyword as defined in RFC 2326. This document defines npt-range acceptable parameters as follows:
npt-range = ( npt-time "-" [ npt-time ] ) | ( "-" npt-time )
npt-time = "now" | npt-sec | npt-hhmmss
npt-sec = 1*DIGIT [ "." *DIGIT ]
npt-hhmmss = npt-hh ":" npt-mm ":" npt-ss [ "." *DIGIT ]
npt-hh = 1*DIGIT ; any positive number
npt-mm = 1*2DIGIT ; 0-59
npt-ss = 1*2DIGIT ; 0-59
Further to this however, the vlm_MediaControl function within src/misc/vlm.c source file expects the seek position parameter to be supplied as a percentage of the total film length (rather than an absolute normal play time as parsed from the Range header) - This disjoint between expected and supplied parameters is likely to also contribute to the mixed behaviour seen with respect to Range header support.