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

[Vladimir Mosgalin]

Hi Ivan Kalvachev!

 On 2006.04.06 at 10:50:20 +0300, Ivan Kalvachev wrote next:

> 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.

You are right about the origin of the problem. But something must be
changed for sure. Because right now all the people I know who use
mplayer don't understand how it should work. And I tried using it
numerous times, I just can't remember whether I need positive or
negative audio delay if the audio lags behind the video, for example.
The only way is to try some big shift, like 1 sec and discover it each
time this feature is needed. Don't you think that something SHOULD be
done for sure?

I think that there is no way to get it right with using short
expressions like "a-v delay". The correct solution would be:
1) - decreases the value, + increases the value
2) the new (long) message should be "audio lags behind the video by ..",
   or "audio is ahead the video by ...". They mean opposite, and the one
   that preserves old behaviour probably should be picked. I.e. "-" will
   now decrease the value, unlike before, but if the overall meaning
   will be reversed, old users won't be confused. And there are no
   problems with reversing the meaning at all.
3) another way to do this is to get rid of negative values and use
   _both_ phrases with positive-only value, depending on current
   situation. This will make controls slightly worse, but it would be
   easier to understand (wtf is "lags by -0.1 sec"?). Also the current
   change of + and - behaviour can be rolled back, since it gives
   problem for people who took default input.conf a long time ago and
   then customized it, so + and - is already redefined there. It
   wouldn't matter at all whether "+" decreases the value since you
   won't see any negative values on the screen. This way, the old
   behaviour can be preserved for everybody, whether they remember what
   "a-v delay" means or not and whether they had redefined +/- or not.


I liked "audio lags behind the video" message when I started writing
this, but now I think that idea in 3) is much better ;)

-- 

Vladimir