[MPlayer-dev-eng] [PATCH] switch audio delay keys

Ivan Kalvachev ikalvachev at gmail.com
Thu Apr 6 09:50:20 CEST 2006


2006/4/5, Uoti Urpala <uoti.urpala at pp1.inet.fi>:
> On Tue, 2006-04-04 at 19:16 -0400, The Wanderer wrote:
> > To address Ivan's other original point, about "delay is something
> > relative": this is true, but since the name is "audio delay" it is
> > reasonable to expect that the audio is what is being delayed - and thus,
> > that increasing the delay factor will make the audio come later. As
> > things presently stand that is not the case. Additionally, the
> > signedness of the argument to the '-delay' option (which sets the
> > initial delay factor to something other than zero) is presently inverted
> > from the signedness of the increase/decrease keys, so a change would
> > have to be made in any case.
>
> There are three directional things:
> - whether audio or video is ahead of the other
> - whether the "delay" setting is positive or negative (the value of this
>   setting is displayed to the user when adjusting it at runtime and is
>   also settable from the command line, so it's not just an internal
>   detail)
> - whether you get to this state by pressing '+' or '-'.
>
> The first one is kind of arbitrary relative to the others and depends on
> the interpretation of the option name (but I agree that "audio delay"
> sounds like positive values should make audio lag behind video). However
> the last two have a natural relation: '+' should correspond to positive
> values and '-' should correspond to negative values. Currently it's the
> opposite.
>
> Currently positive audio_delay means that audio comes ahead of the video
> (contrary to the intuitive interpretation of the option name). No one
> has proposed a patch to change this yet. The two related patches posted
> so far are my patch that fixes a/v sync adjustment when the delay value
> is changed at runtime (this is a real bug, not just an user interface
> consistency issue) and Diego's patch that makes the default keybindings
> use '+' for increase and '-' for decrease instead of the opposite.

I think that now i get what is the problem.

The word "delay".

It is the word that implies negative values. I guess that the word
delta or difference would be more correct.

If we talk about PTS, then then pressing "+" we make the audio pts
bigger than video one, so
A-V  is positive and audio is ahead of the video. However word delay
implies that the audio is behind video thus negative....

So... as of now the audio and subtitles are controlled by similar
manner, with this patch the things go opposite, that would create only
more confusion.




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