[vorbis-dev] Re: Re: How is 6 channels coupling made?

[MiwongShaib]

----- Original Message -----
From: "ChristianHJW" <christianhjw at users.sourceforge.net>
To: <vorbis-dev at xiph.org>
Sent: Tuesday, September 10, 2002 8:16 AM
Subject: [vorbis-dev] Re: Re: How is 6 channels coupling made?

<p>>
> "MiwongShaib" <miwongshaib at hotmail.com> schrieb im Newsbeitrag
> news:OE32tUHzXrJGpkeH9ur00002c6d at hotmail.com...
> > > unfortunately there is no channel coupling used at all when doing 6 ch
> > > Vorbis encodings, thats why files are currently bigger than they should
> be
> > Thanks for telling.
> > This makes things easier for me: it's safer to patch the bug like this
> > Just curious: is there any channel coupling when encoding 2ch (stereo) ?
>
> Of course there is, depending on q level. For q > 5 lossy mode is disabled,
> thats why from 4.99 to 5.0 there is a rather huge jump in bitrate.

How much does the coupling gain? From my encodings with OggDS seems nothing!
A 6 channel encoding is 2.3 times larger filesize than 2 channels encoding at
the same quality.
Of course the additional channels (expecially the subwoofer) have less sound
than FL and FR, but it seems to me that coupling doesn't gain much.

Or maybe Tobias has disabled any coupling, even in 2ch, in order to be flexible
to the number of channels entered?

> ...
>
> But its not the recommended way to use Tobias's
> filters for encoding in any case, bith DSPguru and DarkAvenger update their
> tolls much more frequently.

You mean that you would prefer making an additional encoding step with Headac3he
than wasting 50 MB for a somewhat larger audio track?

<p>> > I'm not sure if I should release such a patching-filter to the public. I
> want
> > Tobias to fix that!
>
> Agree here

Good

Thanks everybody
Gabriele
--- >8 ----
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