[pulseaudio-discuss] VLC, PulseAudio and large tlengths

Maarten Bosmans mkbosmans at gmail.com
Sun Aug 21 00:24:48 PDT 2011

2011/8/21 Tanu Kaskinen <tanuk at iki.fi>:
> On Sat, 2011-08-20 at 23:31 +0300, Rémi Denis-Courmont wrote:
>> It is thus essential that the stream gets triggered approximately on time,
>> whether that is initially, upon resuming from pause, or upon recovering from
>> underflow. Otherwise, resampling kicks in and you get to hear Doppler.
> The resampling shouldn't be hearable if it speeds up the stream at most
> 2% (or at least there are such comments in Pulseaudio source code where
> similar adaptive resampling is done). I'd guess slight resampling would
> be good for small drop-outs. For longer gaps the catch-up time might be
> too long and the initial difference between video and audio too
> noticeable, so dropping some audio would be better to get done with it
> quickly.

Actually, that it 2 pro-mille and refers to the jump in sample rate
that should be inaudible. The total difference from the original rate
that can't be detected is really dependent on thinks like type of
source material, absolute pitch of the listener, and whether the audio
is playing alone or together with something else. For pulseaudio I
limited to the total deviation from the original rate to 25%, which is
certainly audible, but it should get there slowly enough that you
can't hear any doppler-like effects.


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