This should not adversely affect LibVLC: more errors cases will lead to
error code returns instead of abnormal termination. It is not strictly
semantically correct though (update to Win7 or above if you care).

MMDevice is not available on older Windows versions anyway. Failing to
load the plugin there is fine. It is even arguably better: it prevents
impossible choices showing in the preferences.

video/mpeg is underspecified, could be ES, PS or TS.
video/MP1S, video/MP2P and video/MP2T are more specific/better
specified (but should only be used internally or in SDPs).

Where the search paths list is not changed, using AC_PATH_PROG(S) has
no useful effects and makes manual override more difficult.

(Compare to Qt code using different search paths.)

Otherwise, it demuxes at max speed without allowing
user to change program

Some streams send clear padded data (probably
due to insufficient remaining data for encryption)

We'll only test on payload start then.

Since we can swap formats, some doesn't provide any or same values

Red over blue was against usability rules

Closed captions are in the same SEI user sections
as H264 according to the spec.

No functional changes.