[MPlayer-advusers] DVB documentation unclear/outdated

[lynx.abraxas at freenet.de]

On 11/02/07 12:11:14, Nico Sabbi wrote:
> lynx.abraxas at freenet.de wrote:
>
> >How is that ment?
>
> now the description in video.xml is crystal-clear

Yepp. Now it's understandable. Thanks.

> >I don't think the examples show a way of transcoding to mpeg4  for  they
> >just
> >have a video filter addition. Have a look for yourself.
>
>
> excerpt from video.xml_
> <para>
> If you want to record it in a different format (re-encoding it) instead
> you can run a command such as
> <screen>
> mencoder -o <replaceable>r1.avi</replaceable> -ovc xvid -xvidencopts
> bitrate=800 .br >     -oac mp3lame -lameopts cbr:br=128 -pp=ci
> dvb://<replaceable>R1</replaceable>
> </screen>
> </para>
>
> change xvid with lavc and adjust the encoding options as you prefer to
> obtain mpeg4
>

I  think  there  is  a  misunderstanding.  I  am  using  transcoding  here for
"transcoding between MPEG-2  and    MPEG-4  (partial  decompression)"  without
decoding  to  raw  and then encoding to mpeg4 (as mentioned at the end of DVB-
doc). If I'm not mistaken decoding to raw and  then  encoding  is  called  re-
encoding  which  is  not transcoding. I'm though not sure if transrating would
apply here as well since they are both mpeg but not the same video formats. In
the  excerpt  it  states  re-encoding  not  transcoding  and so it is for sure
mencoder's task but not what I am looking for.

> >>>6) Last there is "realtime transcoding between MPEG-2  and   MPEG-4
> >>>(partial
> >>>decompression)" mentioned. It seems this is outdated. In my researches I
> >>>found
> >>>out that in 2002 it had been  dropped  off  the  ToDo-list.  I  couldn't
> >>>find
> >>>anything newer to that concerning mplayer/mencoder. Is it possible now?
> >>>
> >>
> >>it's been possible since dvb:// and demux_ts were added to mplayer
> >
> >
> >Doing  some  research  with  your  hint  to demux_ts I wasn't able to find
> >any
> >examples or hints how to transcode my dvb input to a mpeg4 output-file.
> >Could
> >You please provide some?What programme is in charge for transcoding
> >mplayer or
> >mencoder? (I know there is the programme transcode as well;))
>
> mencoder

I'm    referring    to    this     email     from     the     thread     here:
http://lists.mplayerhq.hu/pipermail/mplayer-dvb/2002-August/000668.html

> >What  uses demux_ts: -demuxer lavf or  -demuxer mpegts?
> >
>
> isn't the filename clear enough? demux_ts; anyway -demuxer lavf can be
> used to demux dvb streams, too
>

If  one  is  new and unsure about things concerning DVB, demux_ts is confusing
since  mplayer  -demux  help  yields  mpegts  fitting   to   last   lines   of
libmpdemux/demux_ts.c  but  making  not  much sense to google hit for demux_ts
http://www.arcknowledge.com/gmane.comp.video.mplayer.user.dvb/2006-10/msg00031.html
So  I'm  still  wondering  if  anyhow  one  can use demux_ts with DVB-input to
achieve transcoding in the way I discribed above? So that I  end  up  with  an
mpeg4-file without re-encoding.


> >>>Finally: If I use the keys 'h' or 'k' to change the channel when watching
> >>>dvb-
> >>>t  mplayer  changes  it  but  then  does  not  take any further input
> >>>from
> >>>the
> >>>keyboard.
> >>>
> >>
> >>??
> >
> >
> >Doing some tests I found out that only -vo xv,svga,aa,fbdev allow  me  to
> >use
> >'h'  or 'k' to change the channel without dropping input reads. I am very
> >fond
> >of the vidix driver. Is it a bug that it doesn't work with cvidix nor
> >xvidix?
>
>
> xvidix does accept 'h', 'k' and shows the osd menu. I use it every day

Sorry, my mistake. gmplayer -vo xvidix and 'h'  or 'k'  make  mine  crash  but
mplayer -vo xvidix does work.
Contrary mplayer -vo cvidix and 'h' or 'k' make mplayer change the channel but
when showing the new channel it does not care about any key strokes any  more.
I  think this is somehow connected to dvb:// since 'h'  or 'k' work forever if
I use them with v4l2 mplayer -vo cvidix tv:// -tv ...

Regards,
Lynx