[vdr] VDR-1.3.27: updated cVideoRepacker
Stefan Lucke
stefan at lucke.in-berlin.de
Sat Jul 23 22:02:20 CEST 2005
On Samstag, 23. Juli 2005 21:29, Reinhard Nissl wrote:
> Hi,
>
> Stefan Lucke wrote:
>
> >>> - a quick reminder of why this needs to be changed, and
> >>
> >>VDR's index file for recordings has byte granularity but adresses
> >>complete PES packets. When VDR needs to send an I frame to a device (e.
> >>g. for fast forward or editing cutting marks) it seeks to the index of
> >>the I frame and reads the data up to the next B frame, i. e. it stops
> >>just before the PES packet which contains the start of the B frame. But
> >>it is likely that this packet also contains the tail of the I frame
> >>before the B frame starts. So VDR will read to few data which results in
> >>an incomplete I frame. The result is that xine doesn't show incomplete
> >>frames, i. e. moving a cutting mark results in no screen update.
> >
> > Are there some sample streams available ? I'm asking this because I
> > get an updated picture upon moving cut marks. That is with
> > softdevice running with vdr-1.3.27 and vdr-1.2.1 recordings.
>
> Well, any stream will do, especially HDTV streams. The result depends on
> the implementation. When softdevice displays incomplete frames,
> everything works almost properly. Maybe you see that part of the image's
> last slice may be black or garbage.
>
> xine-lib discards incomplete frames. The problem exists for quite a long
> time already. My first approach in successfully displaying a still
> image was to send the data 4 times to xine.
Thats the same as softdevice does.
> But this didn't work anymore
> when I wanted to edit cut marks for the HDTV broadcast Spiderman.
Oh, I never tried HDTV streams.
> After
> debugging a lot, I realized that the I frame was incomplete. The last
> slice was completely missing.
>
> With the patches it is now possible to send the still image just once to
> xine, which speeds up moving cut marks accordingly.
That sounds fine. I'll try "sending once" in softdevice too.
Thanks for your explanation.
--
Stefan Lucke
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