[mythtv] ac3 audio problems 0.21-fixes (r16899)

[Daniel Chassot]

On Fri, Apr 4, 2008 at 9:29 PM, Khanh Tran <khanh at khanh.net> wrote:
>
> On Fri, Apr 4, 2008 at 2:13 PM, Mark Spieth <mark at digivation.com.au> wrote:
>  > > > Everything is working great with the upgrade to 0.21-fixes, except AC3
>  > > >  audio.  In an avi file or a DVD, the frontend log fills up with:
>  > > >
>  > > ....
>  > > >
>  > > >  This only happens with files that have AC3 audio.  Everything else,
>  > > >  including live TV and pre-recorded shows works (MP2).  Anyone have any
>  > > >  ideas?  I'm seeing this on my various openSUSE frontends (10.0 through
>  > > > 10.3).
>  > > >  Thanks again for everyone's hard work.
>  > >
>  > > hello,
>  > >
>  > > I made some investigations on this exact same problem last weekend and
>  > > found the problem and the fix.
>  > > The buffering problem comes to the fact that the nuppelvideoplayer
>  > > expect audio not being more than 2s away from the video (value 2000 in
>  > > the code). It seems that this value is too small for some files
>  > > containing AC3 (especially in AVI files).
>  > >
>  > > To fix the problem, I had to increase this limit from 2000 to 4000 in
>  > > the nuppelvideoplayer.cpp file.
>  > >
>  > > Not that I'm knowing exactly what I'm doing here, but it fixed the
>  > > problem. Perhaps some knowledged devloppers can give some insight on
>  > > what the right value (tm) should be.
>  > >
>  > > I will provide you my patch when I get back home.
>  > >
>  > > Daniel
>  >
>  > please try the latest patch in 4764. this corrects this.
>  > there is also an associated mythmusic patch (if you use mythmusic)
>  >
>  > mark
>
>  Running the latest patch from #4764 had some issues (mythtv_ac3.54-v2.patch):
>
>  1 out of 1 hunk FAILED -- saving rejects to file
>  libs/libmyth/audiooutputbase.h.rej
>  3 out of 3 hunks FAILED -- saving rejects to file
>  libs/libmyth/audiooutputbase.cpp.rej
>
>  So I had to edit audiooutputbase.h and audiooutputbase.cpp manually,
>  but now it wont compile:
>
>  audiooutputbase.cpp: In member function 'virtual int
>  AudioOutputBase::GetAudioBufferedTime() const':
>  audiooutputbase.cpp:684: error: passing 'const AudioOutputBase' as
>  'this' argument of 'virtual int
>  AudioOutputBase::GetAudiotime()' discards qualifiers
>  make[2]: *** [audiooutputbase.o] Error 1
>  make[2]: Leaving directory
>  `/home/mythtv/Documents/download/mythtv-0.21-fixes/mythtv/libs/libmyth'
>  make[1]: *** [sub-libmyth] Error 2
>  make[1]: Leaving directory
>  `/home/mythtv/Documents/download/mythtv-0.21-fixes/mythtv/libs'
>  make: *** [sub-libs] Error 2
>  mythtv at livingroom:~/Documents/download/mythtv-0.21-fixes/mythtv>
>
Here is the patch I use on my side.
I didn't look at what Mark proposed yet.

Just to explain a little how I get the value, changing manually the
audio sync (via the menu) with a value of 200 ms was getting the thing
right. As the sync can be adjusted by 1 sec max in the other
direction, I ended up with barely 3.2 s to get something working with
my files, then I choose to use 4 in order to have some more margin.

Hope this helps

Daniel
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