High speed playback 8x, 16x, 32x

[uoti.urpala at pp1.inet.fi (Uoti Urpala)]

On Thu, 2010-05-20 at 11:28 -0500, Luke Massey wrote:
> I am using a named pipe to control mplayer and can't get it to play back
> above 4x.  The man page says up to 100x should work, but when I try to
> set playback speed above 4x, Mplayer just sets it at 4x.  I was
> wondering if this might be a limitation of the video codec or the remote
> control protocol.  I can re-encode the video in any format necessary.  I
> also don't mind modifying source code if I need to.  What can I do to
> get MPlayer to play back at 8x, 16x, 32x, etc.?

This is a limitation of the audio resampling filter that is being used
in your case; it refuses to accept parameters outside a certain range
(though IIRC things worked fine when I once tested just removing that
limit). The simplest workaround is to use "-af scaletempo". The main
effect of this is to use a pitch-preserving filter for audio speedup
instead of the default resampling; this filter happens not to share the
same limit.