[MPlayer-users] Audio click when speed changed

[Reimar Döffinger]

On Mon, May 19, 2014 at 09:43:12PM -0500, Chris Crochet wrote:
> On Sun, May 18, 2014 at 11:50 AM, Reimar Döffinger <Reimar.Doeffinger at gmx.de>
> wrote:
> > So instead I added a (not too bad) hack to scaletempo.
> > I am fairly confident that the issue should be gone now as long as you
> > use -af scaletempo.
> > Though I admit I only tested it with the only sample where I managed to
> > really notice the issue, and that was a trivial 1kHz sine.
> > But that one definitely came out 100% smooth through all speed changes.
> > That change is in r37204.
> 
> I tried r37205 today, and found it eliminates almost all clicks.
> 
> The remainder seem to occur when speed crosses from >1.0 to <1.0, or vica
> versa.  Which occurs with some regularity, because my sychronization
> algorithm on the clients hunts around a bit for the optimal speed, due to
> jitter in the timebases.  But I can still avoid the clicks by setting the
> master to play at speed 1.02, so that once in sync, jitter never causes the
> client speed to go below 1.0.

I haven't seen this issue. I forgot the one issue I noticed though:
If you start with 1.0 the filter will not do anything and it will
not cover up the clicks when it gets activated.
By starting with -speed 1.0001 I couldn't notice it anymore though.
That included when going back to 1.0, though in theory the
filter should request being removed at 1.0...
Either way, I suspect you might avoid using exactly 1.0 as speed.