[MPlayer-dev-eng] [PATCH] hwac3 support DTS WAV passthrough

[Ulion]

2007/11/17, Reimar Doeffinger <Reimar.Doeffinger at stud.uni-karlsruhe.de>:
> Hello,
> On Sat, Nov 17, 2007 at 04:31:51AM +0800, Ulion wrote:
> > 2007/11/13, Ulion <ulion2002 at gmail.com>:
> > > Original hwac3 only support 48kHz sample rate to passthrough, and only
> > > support 16bits BE DTS audio stream. Indeed that's only 1 of 4 DTS
> > > audio stream format, there also have 16bits LE, 14bits BE, 14bits LE.
> > > Specially, normal DTS WAV is 44.1kHz 14bits LE DTS stream.
> > > There's one way to passthrough DTS WAV is add '-ac +pcm' to force
> > > mplayer treat it as raw pcm format, some receiver will detect the DTS
> > > audio and play it well.
> > > But some receivers does not support passthrough by this method, so I
> > > try to find out a way to passthrough it just like normal DTS track in
> > > movies. We need to modify ad_hwac3 to make it support more dts format,
> > > but after did this, we still have problem to passthrough DTS WAV,
> > > that's because the fsize of DTS WAV is 4096 if it's in 14bits mode,
> > > and the sample number per channel (nblks*32) is 1024, then 1024 * 2ch
> > > * 2(16bits sample size) just equal the fsize 4096, that make us have
> > > no space to add an IEC 61937 header for the passthrough.
> > > But finally I found a way to resolve this problem -- convert the
> > > stream from 14bits format to 16bits format, that will save spaces then
> > > we can add the IEC header, after convert, the fsize changed to 3584.
> > > Now we can passthrough DTS WAV by hwac3, tested on both Intel and PPC.
> > > If you want some sample to test, goto these site:
> > >
> > > http://www.sr.se/multikanal/english/e_index.stm
> > > http://www.kellyindustries.com/sounds.html
> > >
> >
> > If no objects, I will commit this in a week.
>
>
> Well, it is a rather big patch, it would be much appreciated if you could find
> a way to split it a bit (it does not matter if the intermediate code has no real
> improvment, if at least you can think of different, descriptive commit messages
> for each).
> Also I'd much appreciate if you could split the comments at something around 80
> characters.

It should be, thank you for notification, I will do that.


-- 
Ulion