[vdr] Re: Curious behaviour with radio record

["Dr. Werner Fink" <werner@suse.de>]

On Wed, Dec 22, 2004 at 09:42:34PM +0100, kafifi wrote:
> >Under vdr-1.3.17, I've recorded 60 minutes of radio emission;
> >when I've tried to replay, edit and cut it, I found a curious behaviour :
> >1/ vdr is displaying only 27 minutes instead of  60 minutes.
> >2/ in video0 directory : 001.vdr, 002.vdr, 003.vdr etc... are only 9.4 MB
> >files.
> >3/ It's very difficult to edit the radio record : it's impossible to move
> >thinly along the record,
> >cursor is moving too fast and very irregularly.
> 
> >Do you notice this strange behaviour in radio records ?
> >Is it a bug of vdr under radio record, or did I missed something ?
> 
> >Fix reported back in November but it has yet to make it in to vdr:
> >http://www.linuxtv.org/mailinglists/vdr/2004/11-2004/msg00081.html
> 
> =====================================================
> ....
> The solution I worked out was to force synced = true for radio recordings: I
> can see no bad effects from this, apart from the aesthetics of it being
> impossible for it to be synced in practice!
> 
> --- remux.c.orig        2004-10-24 10:25:33.000000000 +0100
> +++ remux.c     2004-11-03 10:43:41.000000000 +0000
> @@ -541,6 +541,8 @@
>       // XXX but it would probably be best to only use '0'
> +     // Force syncing of radio channels to avoid "no useful data" error
> +     synced = true;
>       if (PictureType)
>          *PictureType = I_FRAME;
>       return resultBuffer->Get(Count);
> 
> Some of the line numbers may have changed (that was for vanilla vdr-1.3.15)
> but it shouldn't be hard to patch by hand.
> Since patching this, I have had no problems with radio recordings.

IMHO the word `synced' is not what it seems like. It is
something like `I-frame boundary crossed'
... it has nothing to do with A/V synchronization ;^)

       Werner
> 
> Does someone have an idea how to fix that ?

For non-Video data the condition to wait on a I-frame
is not sufficient.

Btw: How difficult it is to generate black pictures in Video
Mpeg to fulfill the Audio offset of around one GOP with
`black' I-Frames on data streams _with_ Video included.
I'm thinking about a function like

       pict = fade_pict(x, y, &size);

for pict(ure) with the resolution x and y for including
into the remuxers part of handling video payloads.



           Werner

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