[mythtv] sound during fast forward/rewind on pvr350 when using it for tv-out

[Joseph A. Caputo]

On Friday 19 March 2004 15:38, jose rubio wrote:
> On Thu, 2004-03-18 at 12:45, Joseph A. Caputo wrote:
> > On Thursday 18 March 2004 11:57, Simon Kenyon wrote:
> > > David Engel wrote:
> > > >On Thu, Mar 18, 2004 at 01:49:44PM +0000, Simon Kenyon wrote:
> > > >>with ivtv-fb. when i fast forward to rewind then it plays brief
> > > >>sequences of video as it goes. unfortunately, it also plays
> > > >> brief snatches of audio as well, which IMHO is annoying. this
> > > >> does not
> > > >
> > > >It's a known problem.  I don't know when it will get fixed since
> > > > it requires a significant change to the way Myth does ff/rew.
> > >
> > > oh well. i'll have to live with it so
> > > thanks for the quick answer
> >
> > You could use the 'trick play' feature instead of bona-fide ff/rew.
> >
> > Pro/cons:
> >
> > + gives 'smooth' rather than 'jumpy' ff/rew
> >
> > - requires more CPU, as it actually decodes every frame, as opposed
> > to skipping them like ff/rew does
> > - max. speed is lower than ff/rew
> >
> > That said, I think ff/rew should be able to be re-worked so that it
> > doesn't play sound.  Trick play obviously does it.
> >
> > This has been an item on my list for a long time.  I wrote the
> > initial implementation of the current ff/rew behavior, and at the
> > time there was no clean way to mute the sound during ff/rew without
> > modifying NuppelVideoPlayer, which Isaac didn't want me to do at
> > the time.  Later the 'mute' functionality was added, and I thought
> > I might be able to utilize that, but it would have been a kludge,
> > and since the mute function doesn't maintain state, there was no
> > elegant way to determine if the sound should remain muted or not
> > when exiting ff/rew.  Then the trick play features were added, and
> > I seem to recall ended up touching NuppelVideoPlayer to do
> > things... I guess the author was able to make a better argument
> > than I did at the time.
> >
> > Maybe I'll revisit this, but actually it's not a priority right
> > now; I think I'm going to remap my ff/rew keys to do trick play. 
> > Anyone else is welcome to take a stab at it...
> >
> > -JAC
>
> OK so I'm gonna sound stupid here but...
>
> What is the 'trick play' feature?

Speed up/slow down playback.  According to keys.txt:

- U to increase the play speed
- J to decrease the play speed

This is different than ff/rew, as I've described... the 'trick play' 
features give a smoother playback, since they're not skipping frames 
but simply changing the playback rate.  For fast playback this of 
course this means decoding more frames per second, so it comes at the 
expense of a higher CPU load (if I had to guess, anyway).

-JAC