[vdr] RE: [ANNOUNCE] VDR developer version 1.3.37

Martin Dauskardt md001 at gmx.de
Mon Nov 28 07:34:13 CET 2005

> From: Klaus Schmidinger <Klaus.Schmidinger at cadsoft.de>
> - Modified switching to Dolby Digital audio in live mode, if the driver
>    and firmware can handle live DD without the need of a Transfer
> Mode (thanks
>    to Werner Fink). Live DD mode requires a full featured DVB card and a
>    LinuxDVB driver with firmware version 0x2622 or higher. Older
> versions will
>    use Transfer Mode just like before.

I recognized that channel switching to an AC3-channel goes much faster with
Live-AC3, when you comment out some lines in transfer.c and dvbosd.c to turn
off the buffer reserve :

     //XXX This is a very ugly hack to allow cDvbOsd to reduce the buffer
     //XXX requirements in cTransfer if it detects a 4MB full featured DVB
     extern bool DvbCardWith4MBofSDRAM;
     DvbCardWith4MBofSDRAM = osdMem >= 1000000;
//     #endif

Even if you can`t use Live AC3 because of an old driver, it works without
buffer reserve if you use one of Werners latest firmware versions. AC3 in
transfer mode doesn`t need a buffer reserve since firmware 2620.
(o.k., if you use the old 2.4 driver, you will have to compile it with new

My suggestion is to turn off the buffer reserve by default in 1.3.38

Or maybe it is possible to solve this with a new parameter in setup.conf?
Could vdr detect if live AC3 is possible and set the best parameter
(UseBufferreserve=1 or 0) by itself? Just an idea.

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