[MPlayer-dev-eng] [PATCH] demux_ogg: add switch audio control

[Paul TT]

On Fri, 11 Nov 2005 09:53:25 +0100
Moritz Bunkus <moritz at bunkus.org> wrote:

> Hey,
> 
> I do read the list, and I usually read all the threads whose topics
> indicate that they might involve my files.

so sorry if i annoyed your private mails... ;-)

> That being said...
> 
> There are two problems with OGM and audio switching. The first is that
> in order to get all the necessary header packets the OGM demuxer must
> read up to three packets (in case of Vorbis) for each audio stream. As
> we want to support non-seeking streams all packets will have to be
> buffered so that you won't have to seek back.
> 
> This should also allow for what Rich wants: finding the comment
headers
> which is the second header packet.

indeed i was looking at this, and after i found out that way of treating
the comments & packets, i postponed that modification, which doesn't
seem very trivial...

> The second problem is that you must not switch audio tracks if the
> Vorbis codec init packets don't match (third packet). The same might
be
> true for other audio codecs, e.g. AAC. The next problem is that
> mplayer's demuxer layer only supports one stream of each kind (video,
> audio). So you must not switch between different audio types either
> (e.g. from Vorbis to AAC).

yes, it's what it's been done in my patch, i save the format just for
this purpose. assuming the same format, is it correct to try anyway the
switching, (that's what i do), or not?

> So in reality audio switching will not work all that often. Especially
> not if you have one audio track with superb quality and e.g.
director's
> comments in mono or something like this.
> 
> Mosu

thanx for yr answers