[vdr] Re: Idea: Change DVB card while recording

[Usenet-372112@zocki.toppoint.de (Rainer Zocholl)]

huels@iname.com(Stefan Huelswitt)  28.10.01 20:08

Once upon a time Stefan Huelswitt shaped the electrons to say...

>On 28 Oct 2001 Carsten Koch <Carsten.Koch@icem.de> wrote:

>> 1) would even a single frame be lost in the process of simply
>>    switching from one card to another?
>>    After all, switching from 001.vdr to 002.vdr does not loose
>>    frames either.

>This is different because there is no gap when switching files,
>vdr just starts to write to another file without loosing any
>data.

>When changing to a different card, first the recordbuffer has to
>shutdown, then tune the new card, start recording. 

Why not:
first tune the new card
second recordbuffer has to shutdown
third start recording of the new card

That maybe can cause duplicate frames...
(I don't know how deep the buffers of the cards are.)

>I estimate
>that this cost at least 2 seconds, which are lost. I think this
>is noticeable in most cases.


>At 25fps a 12-frame GOP is (nearly) a half second. And did you
>noticed that you have square picture distortions just after the
>cutting point in most cases?
>I think this is because B- & I-frames rely on past frames for
>their incremental picture changes.

Gaps of 100ms are visible.